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					   Component Engineering Training
              Course

                  This Training Course has been compiled and is
                          presented by Spur Electron Ltd.




Component Engineering Training Course                             VF No.   1
                  WHAT IS COMPONENT ENGINEERING?

      It is an individual or group which provides the project team with
      a broad knowledge and experience of EEE components,
      including:

      • Electronic and semiconductor theory and principals

      • Materials, construction and manufacture

      • Space component procurement systems

      • Quality and screening requirements




Component Engineering Training Course                              VF No.   2
                        HIGH RELIABILITY COMPONENTS

DEFINITION : A component is defined as :-

The smallest sub-division of a system which cannot be further sub-
divided without destroying its function.

EEE stands for :-

    E Electrical, e.g. Resistors, Capacitors, Connectors
    E Electromechanical, e.g. Relays, Switches, Actuators
    E Electronic, e.g. Integrated Circuits, Transistors, Diodes




Component Engineering Training Course                             VF No.   3
               HIGH RELIABILITY COMPONENTS (CONT.)

Europeans tend to use the word “Component”, whereas the
Americans use the term “Part”. Both terms will be found within this
presentation, and should be considered as synonymous.

Europeans use the term “High Reliability Components, Americans
often use the term “Hi-Rel Part”. Again the terms are synonymous.

High Reliability components are those in which a very high degree
of confidence can be placed that they have stable characteristics
and a working life in excess of the mission requirements.

This definition is flawed, in that the components are manufactured
to a standard set of requirements, whilst mission duration's vary
considerably.



Component Engineering Training Course                          VF No.   4
               HIGH RELIABILITY COMPONENTS (CONT.)

A decade ago mission duration's were typically 3 to 5 years. Today
mission duration's of up to 15 to 20 years are required.

The US Military market has led the field in specifying reliability
standards.

In the mid 1960’s, various government agencies identified that
defects, able to be screened out, were resulting in an equipment
failure rate of about 1% per thousand hours.

In-depth failure analysis identified the predominant failure
mechanisms.




Component Engineering Training Course                                VF No.   5
               HIGH RELIABILITY COMPONENTS (CONT.)


The Solid State Applications Branch of the RADC was assigned the
task of developing a screening procedure to remove the infant
mortality failures, which led to the high failure rates previously
encountered.

In 1968 the RADC staff developed MIL-STD-883.




Component Engineering Training Course                        VF No.   6
                                      THE BATHTUB CURVE



Failure
 Rate




                                             Time in operation
                                                                 Phase III
                 Phase I                      Phase II
                                                                 Wear-Out
                 Infant                       Working Life
                 Mortality
  Component Engineering Training Course                                VF No.   7
OPERATING ENVIRONMENT FOR SPACE COMPONENTS

Environmental Extremes:

• Temperature

• Radiation

• Mechanical Stresses

• Vacuum




Component Engineering Training Course   VF No.   8
    THE EUROPEAN APPROACH TO
        SPACE COMPONENTS




Component Engineering Training Course   VF No.   9
                      ORIGINS OF THE ESA/SCC SYSTEM


Need for Pan-European Specification System for EEE Components
realized by ESRO, prior to the formation of ESA.

Until this need was recognized and acted upon a range of differing
specification systems were being used




Component Engineering Training Course                       VF No.   10
             ORIGINS OF THE ESA/SCC SYSTEM (CONT.)

This resulted in:



-        No standardization.


-        Wide variations in test and inspection philosophies.


-        Huge variances in manufacturers quoted price and delivery.


-        Extreme difficulty in assessing comparative quality and
         reliability of delivered components.

Component Engineering Training Course                              VF No.   11
             ORIGINS OF THE ESA/SCC SYSTEM (CONT.)




In 1971 ESRO through its Joint Programmes and Policy Committee
(JPPC) set up the Space Components Coordination Group (SCCG)
on an interim basis as an advisory group.

Over 30 years later, this interim group is still operating.

In 1973 the JPPC approved the SCCG Terms of Reference.

The SCCG now set about the generation of a series of basic policy
documents.



Component Engineering Training Course                         VF No.   12
             ORIGINS OF THE ESA/SCC SYSTEM (CONT.)



These documents were approved by the SCCG at its plenary
meeting in November 1973 and submitted to the JPPC for its
approval.

Before approval by the JPPC, ESRO and ELDO were merged into
the present day ESA.

ESA then abolished the JPPC, and the SCCG was placed under
the direct authority of the Director General.




Component Engineering Training Course                        VF No.   13
             ORIGINS OF THE ESA/SCC SYSTEM (CONT.)


This new status entailed new terms of reference and redefinition of
responsibilities for both the SCCG and the Director General.

The placement of the SCCG under the Director General's control
was finally approved in 1976.

This ESA policy has been superseded by ESCC and SCAHC




Component Engineering Training Course                        VF No.   14
                 OBJECTIVES OF THE ESA/SCC SYSTEM

The basic objectives of the ESA/SCC System as defined by
ESA/SCC Document No. 00000 “Object and Basic Rules of the
ESA/SCC System” are:

-           Political. The promotion of a European System of
            Specifications for Space Components.

-           Technical. The System capable of being integrated
            with other international systems.

-           Commercial. Promotion of the production in Europe of
            Components suitable for Space Application.



Component Engineering Training Course                           VF No.   15
                 OBJECTIVES OF THE ESA/SCC SYSTEM


-    Standardisation

-    Interchangability

-    Improvement cost/schedule planning




Component Engineering Training Course               VF No.   16
                                    SCCG ACHIEVEMENTS

By the early 1980s the SCCG had achieved a very complete
    ESA/SCC System comprising over 1000 specifications and had
    assisted in the qualification of some 350 components
    manufactured by a total of 40 European manufacturers.
In spite of this success the European user community were very
    concerned that ESA/SCC components were significantly more
    expensive than space qualified components from the US.
There was also a major concern that the SCCG was overly
    bureaucratic and the ESA/SCC System over specified technical
    requirements.
In 1993 ESA published a technical paper recommending some
    major areas of review and modification.
This lead to the formation of SCAHC.


Component Engineering Training Course                      VF No.   17
                                        SCAHC

What was SCAHC?

-    The Space Components Ad Hoc Committee (SCAHC) was
     established by ESA in October 1994

-    It comprised of experts from all the main space sectors within
     Europe. i.e. ESA, National Space Agencies, Commercial Space
     Organisations, Space Industry and Space Component
     Manufacturers. In addition the European Commission was also
     represented.

-    The SCAHC task was to formulate a long term programme for
     space components that would enhance European
     competitiveness in the world market.

Component Engineering Training Course                         VF No.   18
                             SCAHC RECOMMENDATIONS

In a final report released in 1995 the SCAHC made ten recommendations:

R1 – Maintain the ESA/SCC System of specifications including related
     qualification programmes and quality assurance approach in order to
     meet users needs and market trends.

R2 – Standards and specifications for components shall reflect a higher
     degree of delegation from suppliers with reduced customers controls.

R3 – Wherever possible, European component specifications and
     standards should be based on international standards and should be
     promoted to obtain international recognition.




Component Engineering Training Course                              VF No.   19
                   SCAHC RECOMMENDATIONS (CONT.)

R4 – Implement a stringent system for the reduction of diversity of
     components for use in space, based on the usage of a
     European Preferred Parts List, giving preference to European
     components.

R5 – Establish a reliability system for European space Components

R6 – Establish an information Exchange system on component
     data with access for all European users.

R7 – Enable the mutual recognition of industrial performance in the
     various component disciplines, including component
     engineering, radiation hardness assurance, auditing and
     inspection (with formal certification of the latter), through
     provision of the relevant and regular training opportunities.

Component Engineering Training Course                        VF No.   20
                   SCAHC RECOMMENDATIONS (CONT.)

R8 – Improve the availability of strategically important components,
     giving preference to European sources (Microprocessors,
     MMICs etc).

R9 – Implement, in full partnership with the users, manufacturers,
     commercial customers and agencies, a European Space
     Component Research and Technology Programme assuring
     coherence with other market sectors, and cost effectiveness.

R10 – Establish a permanent Component Steering Board (CSB)
     representing the interests of all the European space partners,
     to monitor market trends, to provide financing and to overview
     the technology programmes and its synergies, and advise on
     necessary policy changes.



Component Engineering Training Course                         VF No.   21
                         SCSB ACHEIVEMENTS TO DATE

In the 7 years since the SCAHC recommendations were made
progress has been slow but reasonably successful.
Using the recommendations as a guide we can demonstrate the
following achievements.
R1 Maintain but improve the ESA/SCC system.
Two major contracts awarded. One to review the structure and
organisation, relatively successful, the SCSB now responsible for
the policy and the Executive responsible for the day to day
operation.
Second contract to carry out in depth review. Results very
controversial. However general agreement appears to have been
reached, some changes already incorporated, some still to be
made.


Component Engineering Training Course                        VF No.   22
                       ACHEIVEMENTS TO DATE (CONT.)

R2 Reduce Customer Controls.
Partially achieved by the reduction of deliverable documentation,
now incorporated into the system.
R3 Gain international recognition for the system
NASA now accept ESA/SCC Level B as equivalent to US MIL
Level S
R4 Establish a European PPL
Now available on ESCIES (see later)
R5 Establish a European reliability system
Problem found to be an international concern. NASA and NASDA
are currently involved in seeking solutions.
R6 Establish Information Exchange Database
Now Established (see ESCIES).

Component Engineering Training Course                        VF No.   23
                       ACHEIVEMENTS TO DATE (CONT.)

R7 Enable mutual recognition.
Set of training programmes envisioned. Still not fully initiated.

R8 Improve availability of strategically important components.
Incorporate into CTB activities, see R9 below.

R9 Establish a Component Technology Board.
The CTB is well established and has developed it’s own five year
plan. However funding availability is a major concern.

R10 Establish a Space Components Steering Board (SCSB).
SCSB Charter was formally signed on 8th October 2002


Component Engineering Training Course                               VF No.   24
                      MR. RODOTẦ SIGNS THE CHARTER




Component Engineering Training Course                VF No.   25
                         ESA/SCC STILL THE STANDARD




Even though the ESCC is intended to replace the ESA/SCC
System, it hasn’t yet happened and is unlikely to be complete for a
number of years. In the meantime the ESA/SCC System continues
to be the preferred standard.




Component Engineering Training Course                         VF No.   26
                  RELATIONSHIP TO THE ECSS SYSTEM


The ESA/SCC specification system is a self contained subset of
the ECSS System in that ECSS-Q-00 identifies that components
shall be procured by means of the ESA/SCC specification system,
thus making it a part of the ECSS system.

ECSS-Q-60 is the Level II document applicable for EEE
components. This document clearly identifies the requirement for
maximum use and preference towards the ESA/SCC Specification
System.




Component Engineering Training Course                      VF No.   27
                            ESA/SCC DOCUMENT REF/001
This identifies the existence and status of all documents and
specifications issued on behalf of the Director General of ESA.

It is regularly updated and issued to all registered users of the
ESA/SCC System.

At this time, this document comprises a total of >1000 documents
and specifications, including:-

Percentage of Total Documents
Level 0 Series -Object and Basic Rules                      0.5%
Level 1 Series -Organization, Procedures and Implementation 1.0%
Level 2 Series -Basic Specifications                      10.5%
Level 3 Series -Generic Specifications                      3.0%
Level 4 Series -Detail Specifications                       86%

Component Engineering Training Course                         VF No.   28
                            SCC DOCUMENTARY SYSTEM
                                        FIGURE 1 - SCC DOCUMENTARY SYSTEM


                                                                                        Level 0
                                           Object and Basic Rules of
                                               the SCC System



                                                                                        Level 1
                                                                       Implementation
                       Organisation               Procedures
                                                                        (Agreements)



                                                                                        Level 2
                                           System of Specifications
                                               for Components

                                             Basic Specifications


                                                                                        Level 3
                                             Generic Specification




                                                                                        Level 4
                                             Detail Specifications




Component Engineering Training Course                                                             VF No.   29
       LEVEL 2 DOCUMENTS                  BASIC SPECIFICATIONS

These specifications define the basic requirements for a process,
document or test method.

There is no standard table of contents owing to the wide range of
topics addressed.

Employs either a 5 or 7 digit code,

i.e. either

20400             Internal Visual Inspection

2049000 Internal Visual Inspection of Integrated Circuits


Component Engineering Training Course                        VF No.   30
                    BASIC SPECIFICATIONS (EXAMPLES)


TEST METHODS

22900 Total Dose Steady-State Irradiation Test Method

23800 Electrostatic Discharge Sensitivity Test Method

24800 Resistance to Solvents of Marking Materials and Finishes




Component Engineering Training Course                     VF No.   31
           BASIC SPECIFICATIONS (EXAMPLES) (CONT.)


INSPECTION METHODS

2049000 Internal Visual Inspection of Integrated Circuits

20500               External Visual Inspection

21400               Scanning Electron Microscope Inspection




Component Engineering Training Course                         VF No.   32
           BASIC SPECIFICATIONS (EXAMPLES) (CONT.)

SYSTEM REQUIREMENTS

20100               Requirements for Qualification of Standard Electronic
                    Components for Space Application

21500               Calibration System Requirements

2263502 Evaluation Test Programme for Surface Acoustic Wave
        (SAW) Devices

22800               ESA/SCC Non-Conformance System

24600               Minimum Quality System Requirements




Component Engineering Training Course                              VF No.   33
     LEVEL 3 DOCUMENTS GENERIC SPECIFICATIONS

GENERIC SPECIFICATIONS:
-  Generic meaning “CLOSELY RELATING TO ANY GROUP OR
   CLASS”.
-  It defines the general Inspection, Test and Documentation
   requirements for a group of components.
-  Employs a Four Digit Code, and may refer to a Family of
   components or a Sub-Family of components.

An example to illustrate its use:-
EXAMPLE
4001
40 = Family Code (Resistor Family)
01 = Sub-Family Code (Metal Film)

Component Engineering Training Course                 VF No.   34
                   GENERIC SPECIFICATION CONTENTS



Defines the general requirements for a component family,
including:

Qualification Approval
     Capability Approval
              Procurement
                    Lot Acceptance Testing
                         Delivery
                               Inspection & Test Schedules
                                       Data Documentation



Component Engineering Training Course                        VF No.   35
                               GENERIC SPECIFICATION
                                        TABLE OF CONTENTS
1.          Introduction
2.          Applicable Documents
3.          Terms, Definitions, Abbreviations, Symbols and Units
4.          Requirements
5.          Production Control for Qualification and Capability Approval
6.          Final Production Tests
7.          Burn-in and Electrical Measurements
8.          Qualification Approval, Capability Approval and Lot Acceptance
            Tests
9.          Test Methods and Procedures
10.         Data Documentation
11.         Delivery
12.         Packaging and Despatch
                                  -- Test Flows --
                                        -- Sampling Plans --

Component Engineering Training Course                                  VF No.   36
       GENERIC SPECIFICATIONS (EXAMPLES) (CONT.)



3009          Capacitors, fixed, chips, ceramic dielectric types I and II

4001          Resistors, fixed film

5000          Discrete Semiconductor Components

9000          Integrated Circuits, Monolithics.




Component Engineering Training Course                                  VF No.   37
      LEVEL 4 DOCUMENTS                         DETAIL SPECIFICATIONS

Defines the detail requirements for a component type, including:-
•     Ratings
•     Physical and Electrical Characteristics
•     Test and Inspection Data

                                        TABLE OF CONTENTS
1.          General
2.          Applicable Documents
3.          Terms, Definitions, Abbreviations, Symbols and Units
4.          Requirements
5.          Tables
6.          Figures
7.          Appendices
Component Engineering Training Course                              VF No.   38
                  DETAILED SPECIFICATION EXAMPLES



3009/004                    Capacitors, fixed, chips, ceramic dielectric type I.

4001/011                    Resistors, fixed film, Non hermetically sealed.

5000/005                    Diodes, silicon, fast recovery, avalanche rectifiers,
                            400W.

9000/001                    Monolithic microwave integrated circuits (MMIC),
                            GaAs, Travelling wave amplifier.




Component Engineering Training Course                                         VF No.   39
    COMPONENT NUMBERING - RADIATION IDENTIFICATION




Component Engineering Training Course          VF No.   40
                              RADIATION IDENTIFICATION




Component Engineering Training Course                    VF No.   41
                       OTHER PROCUREMENT SYSTEMS




• CECC

• NASA

• US MILITARY




Component Engineering Training Course              VF No.   42
                                        CECC

The Cenelec Electronic Components Committee (CECC) System
for electronic components of assessed quality became operational
in 1973.

Its object is to facilitate trade by the harmonization of specifications
and quality assessment procedures for electronic components.

Components produced under CECC requirements carry a special
mark and are accepted by all member states.

15 countries participate in the CECC System:-

Austria, Denmark, France, Belgium, Finland, Germany, Ireland,
Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland
and United Kingdom.

Component Engineering Training Course                             VF No.   43
                                        CECC LOGO




Component Engineering Training Course               VF No.   44
                                        CECC (Cont.)

There are a number of different types of approval available within
CECC.
Manufacturers, specialist contractors, distributors and independent
test houses, can each be approved for their particular capability.

Each approval carries its own award of a certificate.




Component Engineering Training Course                         VF No.   45
                                        CECC

Qualification Approval, CECC 00 114:part II

Enhanced Assessment of Quality, CECC 00 114:part IV

Capability Approval, CECC 00 114:part III

Technology Approval, CECC 00 114:part VI

Process Approval, CECC 00 114:part V

Distributor Approval, CECC 00 114:part 1

Test Laboratory Approval, CECC 00 114:part 1


Component Engineering Training Course                 VF No.   46
                                        NASA

The National Aeronautics and Space Administration, NASA, was
formerly established in 1958, to plan and execute the US civil
space programme. It comprises about a dozen major facilities,
employing around 25,000 civil servants.




Component Engineering Training Course                      VF No.   47
                                        MAIN NASA SITES

Goddard Space Flight Centre (GSFC)

Jet Propulsion Laboratory (JPL)

Kennedy Space Centre (KSC)

Marshall Space Flight Centre (MSFC)




Component Engineering Training Course                     VF No.   48
                                        NHB 5300.4

NASA programmes are controlled through a top level handbook,
  NHB 5300.4

This document is imposed on all contractors.

It details the requirements for the control, selection, procurement,
    testing and application of all flight and mission essential EEE
    components.

The hand book is divided into two major sections, Programme
  Management and Component Requirements.




Component Engineering Training Course                           VF No.   49
                                        NHB 5300.4 (Cont.)

The Programme Management Section also identifies the
requirements to provide data to NASA in electronic form.

The Component Requirements Section addresses the detailed
topics directly related to components including, selection and
specification, screening, parts lists, critical parts, derating, GIDEP,
traceability, handling, packaging and storage, qualification and
quality conformance tests, receiving inspection and manufacturer
surveillance.




Component Engineering Training Course                             VF No.   50
                          GSFC PREFERRED PARTS LIST

There are numerous PPLs used within the US space industry,
however the GSFC PPL is considered as one of the best.

It contains a list of preferred parts in two quality levels: Grade 1 for
higher quality/critical applications and Grade 2 for less demanding
applications.




Component Engineering Training Course                              VF No.   51
                                US MILITARY STANDARDS

In the 1950s the US government, in conjunction with the American
armed forces, introduced a series of documents to standardize the
screening flows for electrical and electromechanical components.
The system has continued to evolve, and now includes electronic
components. The objectives being:

   Total product Interchangeability
   Configuration control
   Efficiency of volume production
   Maximum number of approved sources
   These aims have in the most part been achieved




Component Engineering Training Course                       VF No.   52
                                        MIL-STD-883

In the early 1960s the rapidly growing Integrated Circuit industry
was coming of age. It was recognised that the level of defects
attributable to Infant Mortality could be significantly reduced if a
standardized screening flow were introduced. The Solid State
Applications Branch of the Air Forces, Rome Air Defence Center
(RADC) was given the task.




Component Engineering Training Course                            VF No.   53
                                  MIL-STD-883 OBJECTIVE

To create an economically feasible, standardized IC screening
flow, to achieve equipment failure rates of :-

0.085% per 1000hrs., class B (Military)

0.004% per 1000hrs., class S (Space)




Component Engineering Training Course                       VF No.   54
                       883 ORIGINAL SCREENING FLOWS

Originally there were three screening flow classes, A,B and C:-


Class A, critical non-repairable applications
Class B, high reliability, maintainable
Class C, non-critical ground applications


Class A, was superseded by Class S in 1977
Class C, was dropped in 1984, lack of use.




Component Engineering Training Course                         VF No.   55
                          883 DETAILED SPECIFICATIONS

MIL-STD-883 is a collection of test methods designed to look at
specific reliability and quality concerns affecting semiconductor
products.

The specification covers Environmental, Mechanical and Electrical
test methods.

In addition 883 also covers a range of procedures.




Component Engineering Training Course                          VF No.   56
                        883 SCREENING REQUIREMENTS
                                                                  Class S                              Class B
                                  SCREEN
                                                                  Method                    Reqmt      Method                 Reqmt

                                  1. Wafer Lot Acceptance         5007                      All Lots                          _______

                                  2. Non-destructive              2023                      100%                              _______
                                    Bond Pull (Note 14)

                                  3. Internal Visual (Note 1)     2010, Condition A         100%       2010, Condition B      100%

                                  4. Stabilisation Bake           1008, Condition C, Min    100%       1008, Condition C      100%
                                    (Note 16)                     24 hrs. Min.                         min, 24 hrs. Min.

                                  5. Temp. Cycling (Note 2)       1010, Condition C         100%       1010 Condition C       100%

                                  6. Constant Acceleration        2001, Condition E (Min)   100%       2001, Condition E      100%
                                                                  Y1 Orientation Only                  (Min) Y1 Orientation
                                                                                                       Only

                                  7. Visual Inspection (Note 3)                             100%                              100%

                                  8. Particle Impact Noise        2010, Condition A (Note   100%                              _______
                                    Detection (PIND)              4)

                                  9. Serialisation                Note 5                    100%                              -------

                                  10. Interim (Per Burn-In)       Per applicable Device     100%       Per applicable         _______
                                    Electrical Parameters         Specification (Note 13)              Device Specification
                                                                                                       (Note 6)


                                  11. Burn-in Test                1015                      100%       1015                   100%
                                                                               o                                    o
                                                                  240 hrs @ 125 C                      160 hrs @ 125 C
                                                                  Min (Cond F not                      Min
                                                                  allowed)

                                  12. Interim (Post-Burn-In)      Per Applicable            100%
                                    Electrical                    Device Specification
                                                                  (Note 13)

                                  13. Reverse Bias Burn-In        1015; Test Condition      100%
                                    (Note 7)                      A,C,
                                                                  72 ins. @ 150oC
                                                                  Min. (Cond F not
                                                                  allowed)

                                  14. Interim (Post-Burn-In)      Per Applicable Device     100%       Per Applicable         100%
                                    Electrical                    Specification (Note 13)              Device
                                                                                                       Specification

                                  15. PDA Calculation             5% Parametric (Note       All lots   5% Parametric          All lots
                                                                  14)                                  (Note 14)
                                                                  3% Functional




Component Engineering Training Course                                                                                                    VF No.   57
              883 SCREENING REQUIREMENTS (CONTD)
                                                         Class S                                 Class B
                             SCREEN
                                                         Method                  Reqmt           Method           Reqmt

                             16. Final Electrical Test   Per applicable Device                   Per applicable
                                                                                 100%
                                (Note 15)                                                        Device           100%
                                                                                 Specification
                                (a) Static Tests                                                 Specification
                              1) 25oC (Subgroup 1)
                                  Table 1, 5005)
                                                                                 100%
                               2) Max and Min                                                                     100%
                                    Rated Operating
                                    Temp (Subgroups
                                    2,3 Table 1,5005)
                                 (b) Dynamic Tests or
                                    Functional Tests
                                        o                                        100%
                                  1) 25 C (Subgroups 4                                                            100%
                                    or 7)
                                  2) Max and Min                                 100%                             100%
                                    Rated Operating
                                    Temp (Subgroups 5
                                    and 6 or 8,
                                    Table 1,5005)
                                 (c) Switching Tests
                                       o                                         100%
                                    25 C (Subgroup 9                                                              100%
                                    Table 1,5005)


                             17. Seal Fine, Gross        1014                    100%            1014             100%
                                                                                 (Note 8)                         (Note 9)

                             18. Radiographic            2012 Two Views (Note    100%            _______          _______
                               (Note 10)                 15)

                             19. Qualification or        (Note 11)               Samp.           (Note 11)        Samp.
                             Quality Conformance
                               Inspection Test Sample
                             Selection



                             20. External Visual         2009                    100%                             100%
                               (Note 12)




Component Engineering Training Course                                                                                        VF No.   58
   38510 - QUALIFICATION AND QUALITY CONFORMANCE TESTING

Each of the flows requires qualification and quality conformance testing.

The quality conformance testing frequency is defined in MIL-M-38510
(JAN product) and paragraph 1.2 of 883 (non-JAN product).

Quality conformance testing is divided into 5 groups, A, B, C, D
and E.

Group A :                   Sample electrical testing
Group B :                   Sample constructional tests
Group C :                   performed only on class B product. Sample
                            reliability testing
Group D :                   Sample package related testing
Group E :                   Only required where a radiation hardness
                            requirement identified.



Component Engineering Training Course                                   VF No.   59
                                 MIL-STD-883   SUMMARY

883 provides a valuable tool for the Military and Space
semiconductor user.

However it does not provide the specific device electrical
requirements necessary to achieve standardization.

This is established by MIL-M-38510




Component Engineering Training Course                        VF No.   60
                                        MIL-M-38510

Concurrent with the development of MIL-STD-883, RADC
developed MIL-M-38510

MIL-M-38510, establishes the procedures which a manufacturer
must follow to have his products listed in the Qualified Parts List

Also published a set of performance and electrical parameters,
(slash sheets)




Component Engineering Training Course                           VF No.   61
                                 OBTAINING QPL LISTING

A manufacturer must meet the following requirements before
obtaining QPL listing

Line Certification as defined within MIL-STD 976

Device Qualification. There are two levels of QPL listing. Part II
requirements are significantly less than Part I.

Part II listing was established to expedite manufacturers into the
QPL.




Component Engineering Training Course                           VF No.   62
                         OBTAINING QPL LISTING (Cont.)

To obtain Part II listing, all line certifications must be complete and
significant electrical, design and constructional test data submitted,
and approved.

Part I listing requires significant additional testing and therefore
takes much longer to complete.




Component Engineering Training Course                             VF No.   63
                          QUALIFICATION BY EXTENSION

There are three ways to extend device or package qualification.

• Die related testing
• Die extension
• Package extension

In addition it is possible to extend qualification to differing lead
finishes.




Component Engineering Training Course                              VF No.   64
                       PART NUMBERING AND MARKING

MIL-M-38510 devices have a unique part numbering system.
e.g. JM38510/AAABBCDE:

J =            JAN prefix

M38510                       =          MIL-M-38510

/    =        Replaced by hardness assurance letter, when

              applicable




Component Engineering Training Course                       VF No.   65
                PART NUMBERING AND MARKING (Cont)

AAA            =              Slash sheet no.

BB            =              Component no. on the slash sheet

C =           Screening level S or B

D =           Component package type.

E =           Lead finish

e.g.   JM38510/10107SGC = Slash sheet 101 device 07(LM118)
   Class S, in 8 pin, TO-99 package with gold finish.


Component Engineering Training Course                           VF No.   66
                                        MIL-I-38535

Over the past decade, standards have not been able to keep pace
with the rapidly changing technologies.

MIL-M-38510, which is very successful for simpler components was
not suited to complex technologies such as ASICs, gate arrays and
VLSI components.

As a result the Qualified Manufacturers List (QML) approach was
implemented through MIL-I-38535

The QML approach is to qualify the manufacturer, rather than his
specific products.



Component Engineering Training Course                        VF No.   67
                                        MIL-I-38535 (Cont.)

The manufacturer adopts a Total Quality Management (TQM)
approach to his business.

This applies from the initial design phase through to customer
feedback.

The objective is to demonstrate, through Statistical Process Control
(SPC), continuous improvement.




Component Engineering Training Course                            VF No.   68
                                        MIL-S-19500

To date the information related to the US-MIL System has related
to ICs.

Similar reliability concerns are held with respect to other EEE
components.

This section deals with discrete semiconductor devices, incl. FETs,
bipolar transistors, diodes, rectifiers and thyristors.

In 1959 the United States Navy Bureau of Ships, created MIL-S-
19500, which performs the same function for discrete
semiconductor products, that MIL-M-38510 provides for ICs.

MIL-S-19500 was tailored to work with the JEDEC numbering
system.

Component Engineering Training Course                             VF No.   69
                                        MIL-S-19500 (Cont.)

The JEDEC numbering system is simple in that a three or four digit
number was preceded by an XN, where X is one less than the
number of active element terminations on the device.

Thus a diode has two terminations, X = 1.

Transistors generally have three terminations, thus X = 2

Dual transistors were also given a 2N number, even though their 6
pins would suggest a 5N number.

Suffixes were added to provide additional information e.g. M for
matched pair.



Component Engineering Training Course                         VF No.   70
                                        MIL-S-19500 (Cont.)

In 1963 the Navy decided that it would be better to have a separate
specification for detailed test methods.

In 1964 MIL-STD-750 was published as a “how to” of test methods
for MIL-S-19500.

MIL-S-19500 establishes general requirements

Detailed requirements are specified in detail specifications.

4 levels of PA requirements are specified.
JAN,JANTX,JANTXV and JANS.


Component Engineering Training Course                           VF No.   71
                             MIL-S-19500 QUALIFICATION

Before any supplier can deliver any level of JAN semiconductor
products, he must undergo a formal qualification cycle.

This qualification cycle is much like that already identified for MIL-
M-38510.

Once qualified the manufacturer is listed in QPL-19500.

To retain QPL listing the manufacturer has to submit, each year, a
summary of all of the quality conformance testing that has been
completed.

If any changes are made to the QPL listed components that affect
performance, quality, appearance, reliability or Interchangeability,
re-qualification may be required.

Component Engineering Training Course                             VF No.   72
               MIL-S-19500 SCREENING REQUIREMENTS
                                                               MIL STD                                    JAN        JAN          JAN
                                           Screen                750              Condition                S         TXV           TX
                                                               Method                                    Reqmt      Reqmt        Reqmt
                                      1. Internal Visual        2072           For Transistors           100%        100%         ____
                                      (Precap) Inspection       2073      For diodes when specified
                                                                2074              For diodes
                                      2. High Temp Life         1032       24 hrs min at max rated       100%        100%         100%
                                           (LTPD)                               storage temp
                                      (Stabilisation Bake)
                                      3. Thermal Shock          1051     No dwell is required at 25oC    100%        100%         100%
                                    (temp cycling) (Note 6)              Test condition C, 20 cycles
                                                                          t(extremes) > 10 minutes
                                   4. Constant acceleration     2006     Y1 direction at 20,000G min     100%        100%         100%
                                        (not required for                 (10,000G min for devices
                                       double plug diodes)                with power rating of > 10
                                                                                              o
                                                                             watts at TC = 25 C).
                                   5. Particle Impact Noise     2052             Condition A             100%        ____         _____
                                         detection (for all
                                         devices with an
                                          internal cavity)
                                   6.(a) Forward instability    2081                                     100%        _____        _____
                                               shock test
                                            (FIST) (Note 5)
                                    (b) Backward instability
                                               shock test       2082                                     100%
                                           (BIST) (Note 5)
                                       7. Hermetic Seal         1071       (a) Test condition G or       Option    100% (Note   100% (Note
                                              (a) Fine                         H1 max leak rate =            al        8)           8)
                                           (not required for                   5 X 10 -8 atm cc/s        if done
                                        double plug diodes)                     for devices with            at
                                                                                internal cavity >        step 14
                                                                                     0.3 cc)
                                           (b) Gross                          (b) Test condition
                                                                                  A, C, E or F           Option
                                                                                                            al
                                       8. Serialisation                                                   100%        -----       -----
                                     9. Interim electrical                       As specified             100%       _____       ______
                                           parameters                                                     (Read
                                                                                                           and
                                                                                                         record)
                                    10. High temp reverse                  48 hrs min at TA = 150oV
                                     bias (HTRB) (Note 7)                min and min applied voltage
                                                                                  as follows:
                                                                         Transistor-Cond A, 80% min
                                           Burn-In (for         1039      of rated VCB (bipolar), VGS    100%        100%         100%
                                         transistors)                        (FET), as applicable

                                                                         Diodes (except Zeners) and
                                                                         rectifiers rated < 10 amps at
                                       Burn-In (for diodes      1038       TC > 100oC-80% min of         100%        100%         100%
                                        and rectifiers)                      rated VR-Condition A




Component Engineering Training Course                                                                                                        VF No.   73
       MIL-S-19500 SCREENING REQUIREMENTS (Cont.)
                                                      MIL STD                              JAN              JAN            JAN
                                  Screen                750         Condition               S               TXV             TX
                                                      Method                              Reqmt            Reqmt          Reqmt
                         11. Interim electrical and              As specified but           100%         100% (Read     100% (Read
                             delta parameters                   including all delta      (Read and        and record     and record
                                                                 parameters as a        record delta          delta          delta
                                                                  min. Leakage          parameters       parameters     parameters
                                                                 current shall be      within 16 hrs       within 24      within 24
                                                                measured on each      after removal of      hrs after      hrs after
                                                                device before any     applied voltage     removal of     removal of
                                                                other test is made        in HTRB)          applied        applied
                                                                                                           voltage in     voltage in
                                                                                                             HTRB)          HTRB)
                         12 Power burn-in (Note 4)                 As specified           100%               100%           100%
                          Burn in (for transistors)    1039     Transistors-Cond B      240hrs min        160hrsmin      160hrsmin
                          Burn in (for diodes and      1038      Diodes (including      240hrs min        96hrs min      96hrs min
                                 rectifiers)                      Zeners) and all
                                                                 rectifiers Cond B
                           Burn in (for thyristors     1040         Thryistors          240hrs min        96hrs min      96hrs min
                           controlled rectifiers)

                          13. Final electrical test                As specified            100%             100%           100%
                            (a) Interim electrical                All parameter           Interim          Interim        Interim
                                    and delta                     measurements           electrical       electrical     electrical
                                 parameters for                 must be completed        and delta        and delta      and delta
                                PDA. PDA when                   within 96 hrs after     parameters       parameters     parameters
                               applicable is 10%                removal from burn       (Read and        (Read and      (Read and
                                   maximum                         in condition           Record)          Record)        Record)
                                                                                         Group A
                              (b) Other electrical                                      subgroups         Group A        Group A
                                    parameters                                            2 and 3        subgroup 2     subgroup 2
                             14. Hermetic seal         1071     (same as 7 above)          100%           Optional       Optional
                                (a) Fine (except                    (Note 3)                              (Note 8)       (Note 8)
                            double plug diodes)

                                  (b) Gross
                             15. Radiography           2076          (Note 3)              100%            _____          ______
                            16. External visual        2071      To be performed           100%            _____          ______
                                 examination                      after complete
                                                                     marking




Component Engineering Training Course                                                                                                  VF No.   74
                                        MIL-STD-202

MIL-STD-202 establishes uniform methods of testing for
component parts including: Capacitors, resistors, switches, relays
and transformers. The standard is only intended to apply to small
parts.

The test methods have been prepared to serve several purposes:-

• To give test results equivalent to those existing in actual service

• To provide a standardized, uniform approach to testing

• To provide a range of test methods, that can be applied to
  components not covered by an approved military drawing

Component Engineering Training Course                           VF No.   75
                                        MIL-STD-202 (Cont.)

Classes of tests.                 The tests are divided into three classes:-

•      101 to 199, Environmental

•      201 to 299, Physical characteristics

•      301 to 399, Electrical Characteristics




Component Engineering Training Course                                          VF No.   76
                                        MIL-STD-202 (Cont.)

Revision of test methods are indicated by a letter following the
method number

Thus the first revision to test 101 is 101A, the second 101B etc.

Test sequences are not mandatory, but are provided to give
guidance.




Component Engineering Training Course                          VF No.   77
                                        MIL-STD-202 (Cont.)


     Group I (all of the samples)
            Visual inspection
            Mechanical inspection
            Electrical measurements
            Hermetic seal test (if applicable)


     Group II a (part of sample)                              Group II b (balance of sample)
             Shock                                                    Resistance to soldering heat
             Acceleration                                             Terminal strength
             Vibration                                                Terminal shock


     Group III (all units which have passed group II tests)
             Moisture resistance or seal test on hermetically sealed parts.




Component Engineering Training Course                                                                VF No.   78
     COMPONENT MANUFACTURERS SPECIFICATIONS

Nearly all component manufacturers have their own internal
standards which form the basis for any other customer specification
placed upon them.

These standards cover basic electrical, mechanical and
environmental characteristics.

Increasingly manufacturers are also setting standard screening and
test requirements, from which they are not prepared to deviate.




Component Engineering Training Course                        VF No.   79
   COMPONENT MANUFACTURERS SPECIFICATIONS (Cont.)
                                                                           SGS-THOMSON
                                                              COMMERCIAL SPACE QUALITY LEVEL

                1.   Screening Specification: MIL-STD-883 Class B=, rev D
                                              Pind Test Condition A.

                2.   Electrical Specification:   ESA/SCC Table II (when applicable) or
                                                 SGS-Thomson Data Book.

                3.   Sourcing:                   SCC Qualified Assembly line of Rennes Factory
                                                 SCC Qualified Assembly Materials
                                                 SCC Qualified Assembly Silicon Dices
                                                 SCC Qualified Assembly Generic Quality Rules

                     Traceability: Each Lot identified with a data code with tracking file which is permanently stored in factory. It would not contain
                     wafer tracking data but will grant that utilised wafer are from SCC qualified radhard process.

                4.   Radiation: Guaranteed by Design but not tested:
                     Heavy Ions LU and SEU:      LU Free
                                                 SEU figure available
                     CMOS 4000B Total Dose: 100KRad
                     54HC Total Dose:       50KRad (100Krd upon request)
                     Bias:                  Worst case
                                            Floating Output (Tri-State)
                     Dose Rate:             25 Rad per Hour
                     Tested                 (Idd1, Idd2:     Limit 10/40A
                     Parameters:            (Vth, Delta Vth: as SCC Spec
                                            (Rebound, functionality: as SCC Spec

                5.   Certificate of Conformity and RVT Reports:
                     They are not delivered, Parts conformity to present
                     Quality level being granted by Marking.

                6.   Packages:
                      DIL Ceramic Side Braze (SCC Qualified),
                        metallic Sn-Au soldered lid (Stock items)
                     Upon Request
                      FLAT Ceramic Side Braze (SCC Qualified),
                      LCC Ceramic (SCC Qualified)




Component Engineering Training Course                                                                                                                     VF No.   80
  ESA/SCC TEST AND INSPECTION
         REQUIREMENTS




Component Engineering Training Course   VF No.   81
      ESA/SCC TEST AND INSPECTION REQUIREMENTS

This section covers the various tests and inspections which form
part of the ESA/SCC Specification System for high reliability
components.

In the ESA/SCC System the inspections are divided up into:

- Special In-process Controls
- Final Production Tests
- Burn-in
- Qualification Tests
- Lot Acceptance Tests




Component Engineering Training Course                        VF No.   82
                                         INDIVIDUAL TESTS

Test                                       Category of Test       Probable Procurer’s Inspector Involvement


SEM Inspection                             Destructive            Reviews report
Internal Visual Inspection                 Non-destructive        Performs test
External Visual Inspection                 Non-destructive        Performs test
Electrical Screening Tests                 Non-destructive        Unlikely
High Temperature Stabilisation Bake        Non-destructive        Unlikely
Temperature Cycling                        Non-destructive        Unlikely
Thermal Shock (in Air)                     Non-destructive        Unlikely
Constant Acceleration                      Non-destructive        Unlikely
Particle Impact Noise Detection (PIND)     Non-destructive        Witnesses test
Seal Test                                  Non-destructive        Unlikely
Burn-in                                    Non-destructive        Unlikely
Radiography                                Non-destructive        Review report
Permanence of Marking                      Non-destructive        Unlikely
High Temperature Storage                   Non-destructive        Unlikely
Bond Pull                                  Destructive            Witnesses test
Die shear                                  Destructive            Witnesses test
Mechanical Shock Test                      Destructive Sequence   Unlikely
Vibration                                  Destructive Sequence   Unlikely
Thermal Shock                              Destructive Sequence   Unlikely
Moisture Resistance                        Destructive Sequence   Unlikely
Solderability                              Destructive Sequence   Witnesses test and/or inspects devices
Terminal Strength                          Destructive Sequence   Unlikely
Operating Life                             Destructive Sequence   Unlikely




Component Engineering Training Course                                                              VF No.   83
                       SPECIAL IN-PROCESS CONTROLS

Special tests and inspections which are carried out during
manufacturing with the intention of checking specific processing
steps or sub-components of the final device.

These processing steps or sub-components are ones which have:

 - Been shown to be critical in producing high reliability
components and
 - which cannot be tested or inspected at the end of production.




Component Engineering Training Course                         VF No.   84
                                        WLA

A wafer lot is a set of wafers that been manufactured together and
therefore are from the same diffusion, oxidation and metallisation
lot.

Wafer lot acceptance (WLA) is a series of inspections carried out
on samples of die from a wafer lot. The samples must be taken
from particular locations within the wafer. These positions are
described in ESA/SCC Basic Specification No. 21400 or
MIL-STD-883 Method 5007.6




Component Engineering Training Course                         VF No.   85
                                        SAMPLE SELECTION


1. Proper sample selection is an important part of the examination
   method.

2. Statistical techniques using random selection are not practical,
   because of the large sample needed.

3. Sample selection criteria are based on minimizing test sample
   size yet maintaining confidence in the examination.

4. The selection of wafers is based on their position in the wafer
   holder. Dice at specific locations on those wafers are selected to
   show worst case metallisation processing defects.



Component Engineering Training Course                          VF No.   86
                                        DIE SELECTION PLAN




Component Engineering Training Course                        VF No.   87
                               DIE SAMPLE EXAMINATION


1. All four edge directions shall be examined for each type of
   contact window or metallisation step.

2. Viewing angles & direction shall be chosen so as to accurately
   assess the quality of metallisation.

3. For multi-layered-metal systems, it will be necessary to remove
   the layers one at a time to expose the next underlying layer for
   examination.




Component Engineering Training Course                            VF No.   88
                    SCANNING ELECTRON MICROSCOPE




Component Engineering Training Course              VF No.   89
                                    METALLISATION STEP




Component Engineering Training Course                    VF No.   90
                     EXAMPLE OF INSPECTION DEFECTS




Component Engineering Training Course                VF No.   91
                    ACCEPTANCE/REJECTION CRITERIA


1. Rejection of dice shall be based on lot process orientated
   defects.

2. Rejection shall not be based on workmanship and other type
   defects such as scratches, smeared metallisation, tooling
   marks, etc. Such defects will be rejected at Pre-cap inspection.




Component Engineering Training Course                           VF No.   92
                                   WLA DOCUMENTATION

1. Photographic

-    minimum of 3 SEM, 1 each for worst case metallisation, oxide step &
     contact window.

2. Information traceable to each Photograph

-    Manufacturer’s name & address
-    name & address of test house or laboratory
-    SEM operators/inspectors identification no.
-    Date of SEM inspection & photograph
-    component part, type or reference number
-    SEM inspection lot number or code
-    area forming subject of photograph
-    magnification
-    accelerating voltage
-    viewing angle

Component Engineering Training Course                               VF No.   93
                              FINAL PRODUCTION TESTS

The final step in the manufacture of most types of components is
the final sealing of the component package. The Final Production
Tests are a series of tests and inspections carried out just before
and just after the components are sealed.

Purpose is to look for:
Anomalies in the production lot




Component Engineering Training Course                          VF No.   94
                                        INTERNAL VISUAL

Before sealing the component it should be examined optically to
verify that internal materials, design and construction are in
accordance with the applicable acquisition document.

In the case of integrated circuits the inspection should be
performed at both high and low magnification.




Component Engineering Training Course                         VF No.   95
                                        INTERNAL VISUAL




Component Engineering Training Course                     VF No.   96
                                        INTERNAL VISUAL




Component Engineering Training Course                     VF No.   97
                                   BOND STRENGTH TEST

This test measures bond strengths,evaluates bond strength
distributions or determines compliance with specified bond
strengths required of applied acquisition documents.

The specifications include table and graphs giving the different
bond strengths required for the diameter and material of the bond
wires.

A record should be made of the force at which the bond wire
breaks and the applicable code for the site of break.




Component Engineering Training Course                         VF No.   98
             BOND STRENGTH AND DIE SHEAR TESTER




Component Engineering Training Course             VF No.   99
                                        BOND PULL TEST




Component Engineering Training Course                    VF No.   100
                                   BOND STRENGTH TEST




Component Engineering Training Course                   VF No.   101
                                   BOND STRENGTH TEST




Component Engineering Training Course                   VF No.   102
                                        DIE SHEAR TEST




Component Engineering Training Course                    VF No.   103
                                   DIE SHEAR STRENGTH

This test is used to determine the integrity of materials and
procedures used to attach semiconductor die or surface mounted
passive elements to package headers or other substrates.

Failure criteria is based on:

1. Measure of force applied to die.

2. Type of failure (if failure occurs)

3. Visual appearance of residual die attach.




Component Engineering Training Course                    VF No.   104
                                   DIE SHEAR STRENGTH




Component Engineering Training Course                   VF No.   105
            HIGH TEMPERATURE STABILISATION BAKE


Many components initially display variations in some of their
electrical parameters, but these parameters become stable after a
short time at high temperature.

The ESA/SCC Generic Specification No. 9000 requires devices to
be stored for 48 hours at the maximum storage temperature.




Component Engineering Training Course                       VF No.   106
       TEMPERATURE CYCLING AND THERMAL SHOCK




Component Engineering Training Course     VF No.   107
           PARTICLE IMPACT NOISE DETECTION (PIND)




Component Engineering Training Course               VF No.   108
                    PARTICLE IMPACT NOISE DETECTOR




Component Engineering Training Course                VF No.   109
                                        PIND RESPONSE




Component Engineering Training Course                   VF No.   110
                             RADIOGRAPHIC INSPECTION




Component Engineering Training Course                  VF No.   111
                                        RADIOGRAPHY

The purpose of Radiography is, to confirm the following:-

•    Absence of foreign material within the package.
•    Correct location/mounting of internal elements.
•    Correctly made internal/external connections.
•    Proper sealing of the device.

Radiography has the following drawbacks:-

•    Aluminium bond wires and silicon are almost transparent to X-Rays
•    Additional tests are required to determine whether foreign material
     within the package is loose.
•    Due to unfavourable positioning of the device, a defect maybe
     undetectable


Component Engineering Training Course                            VF No.   112
                                        FINE LEAK TESTING


1. The most widely used fine leak tests are radioactive tracer and
   helium leak detection methods

2. The radioactive tracer test is most sensitive but test is complex
   and hazardous and the equipment is very expensive

3. For the helium test the components are placed in a bombing
   chamber and pressurized in helium gas. The pressure and time
   are dependant on the volume of the package.

4. The components are then transferred to a detector which detects
   the outgassing helium.


Component Engineering Training Course                          VF No.   113
            TYPICAL CONDITIONS FOR FINE LEAK TEST




Component Engineering Training Course               VF No.   114
                                        BOMBING CHAMBER




Component Engineering Training Course                     VF No.   115
                                        FINE LEAK TESTING




Component Engineering Training Course                       VF No.   116
                                   GROSS LEAK TESTING

1. If the component needs to be preconditioned then it is placed in
    D80 perfluorinated fluid and placed in the bombing chamber
    under pressure for a specified amount of time.

2. The component is then immersed in D02 perfluorinated fluid at
   125°C. A stream of bubbles is looked for.

3. Another gross leak test that is used in some circumstances
   i.e. for glass diodes is the dye penetrant test.

     Here the component is placed in a dye penetrant fluid in the
     bombing chamber. After removal and cleaning it is inspected
     with ultraviolet light. Areas where the dye has entered inside
     cavities are easily located.

Component Engineering Training Course                          VF No.   117
    TYPICAL CONDITIONS FOR THE GROSS LEAK TEST




Component Engineering Training Course      VF No.   118
                                        GROSS LEAK TEST




Component Engineering Training Course                     VF No.   119
                         EXTERNAL VISUAL INSPECTION

A low magnification inspection of the external surfaces of parts.

PURPOSE: “To check the external component materials,
construction and workmanship for compliance to ESA/SCC”.

Requirements taken from ESA/SCC Basic Specification series
20500.

Performed after stress tests and as a final inspection prior to
delivery. Generally the final inspection activity.

Can be performed on an AQL basis of 1% in final production tests.
At other times, e.g. screening, it is performed on 100% basis.
Although dimensional check is generally applied on AQL of 1%.


Component Engineering Training Course                             VF No.   120
                     EXTERNAL VISUAL PHOTOGRAPHS




Component Engineering Training Course              VF No.   121
       EXTERNAL VISUAL INSPECTION SHALL INCLUDE THE
                 FOLLOWING EXAMINATIONS

1. Marking

2. Metal Surface

3. Case

4. Feed-throughs

5. Brazed joints

6. Leads



Component Engineering Training Course            VF No.   122
       EXTERNAL VISUAL INSPECTION REQUIREMENTS

Ensure Material and External construction are in accordance with
detail specification.

External surfaces should be clean.
           No corrosion.
           No peeling of finishes.
           No holes or cracks.
           No colour change.

Except for :Tinned surfaces which may show some discolouration
             after endurance or high temperature storage.
            :Even discolouration of body after high temperature
             storage.

Component Engineering Training Course                      VF No.   123
   EXTERNAL VISUAL INSPECTION REQUIREMENTS (CONT.)

Dimensional check - In accordance with the detail specification.

Marking - Legibility and permanence.

Soldered/Braised Joints - Reject if:

                             Solder surface not clean and smooth.
                             Evidence of cracks or voids.
                             Incomplete solder flow or coverage.
                             Balling of solder.
                             Foreign matter in solder.



Component Engineering Training Course                               VF No.   124
                                        DIMENSION CHECK




Component Engineering Training Course                     VF No.   125
          ELECTRICAL SCREENING TEST AND
                     BURN-IN




Component Engineering Training Course   VF No.   126
                         ELECTRICAL SCREENING TESTS

Electrical measurements carried out to confirm that the
components do meet the electrical requirements specified for them
and to remove from the lot any which do not.
It is a check for any electrical degradation which has occurred in
components as a result of any stress tests. The tests can be a full
set of parameter measurements at room temperature, or at high
and low temperature or just a measurement of certain critical
parameters to look for changes.
The details of which measurements must be carried out at any
point and what results are acceptable are given in the detail
specification for each component type.




Component Engineering Training Course                        VF No.   127
                                        BURN-IN




The purposes of Burn-in are two
fold:



- Removal of infant mortalities

- To check the PDA




Component Engineering Training Course             VF No.   128
                    HIGH TEMPERATURE REVERSE BIAS

HTRB is designed to check the ability of a device to continuously
block a voltage under conditions accelerated by both elevated
temperatures and high voltages.

The HTRB is particularly useful when screening defective MOS
devices. The primary failure modes for this stress are the leakage
currents Idss and Igss.




Component Engineering Training Course                        VF No.   129
    QUALIFICATION AND LOT ACCEPTANCE
                   TESTS




Component Engineering Training Course   VF No.   130
                                LOT ACCEPTANCE TESTS

Full ESA qualified parts undergo Lot Acceptance Testing (LAT) on
samples from the production lot. This yields greater reliability
assurance with respect to environmental, mechanical assembly
and endurance of the devices. Within the ESA/SCC system the Lot
Acceptance Tests are specified in Chart V of the appropriate
Generic Specification and indicate which tests are performed, how
many parts are required for each test and how many failures are
permitted for each of the tests.




Component Engineering Training Course                      VF No.   131
                              CONSTANT ACCELERATION




Component Engineering Training Course                 VF No.   132
                          HIGH TEMPERATURE STORAGE

The test is performed by placing the components in a high
temperature chamber for the specified time at a specified
temperature.

Its purpose is to determine whether the components are degraded
by a period of time at their maximum rated storage temperature.

After completion of the storage test, any degradation of the
components is detected by using appropriate end point
measurements such as leak testing, electrical testing and visual
inspection.




Component Engineering Training Course                        VF No.   133
                              MECHANICAL SHOCK TEST


The components are mounted on a shock machine and subjected
to a series of mechanical shocks.

The purpose of this test is to check the mechanical integrity of the
package, particularly the die mounting, wire bonding and package
sealing.




Component Engineering Training Course                          VF No.   134
                                        VIBRATION TEST




Component Engineering Training Course                    VF No.   135
                                        VIBRATION TEST




Component Engineering Training Course                    VF No.   136
                                        THERMAL SHOCK

Components are alternately immersed in liquids at high
temperature and at low temperature.
The number of cycles, the immersion and transfer times, the liquids
to be used and the temperatures to be used are given in the
appropriate specifications.
The purpose of the test is to subject the components to severe
thermal stressing to reveal any mechanical weaknesses.

Any degradation caused by this test is usually detected by
subsequent end point measurements such as leak testing,
electrical measurements or external visual inspection.




Component Engineering Training Course                        VF No.   137
                                  MOISTURE RESISTANCE

Components are subjected to a number of cycles of combined high
temperature and humidity.

Purpose of the test:

- Corrosion

- Moisture ingress.




Component Engineering Training Course                    VF No.   138
                                        OPERATING LIFE

The components are electrically stressed while simultaneously
subjected to a high temperature.

→ accelerated ageing
→ simulating the normal operating life in a matter of weeks.

Arrhenius Equation:                     R=Ae -Eα/kT

Electrical measurements, leak testing, visual inspection performed
at the end of the test to establish whether there is any degradation.




Component Engineering Training Course                          VF No.   139
                           MARKING PERMANENCY TEST




Component Engineering Training Course                VF No.   140
                          PERMANENCE OF MARKING - 1




Component Engineering Training Course                 VF No.   141
                          PERMANENCE OF MARKING - 2




Component Engineering Training Course                 VF No.   142
                                        SOLDERABILITY

This test method is to evaluate the The ability of the terminations to
   be:

1. Wetted by a coating of solder.

2. To produce a suitable solder fillet.

The termination is dipped in flux and allowed to dry for a few
  seconds, then dipped in a solder pot which is at the specified
  temperature for 7 - 10 secs. The termination is then cleaned in
  IPA and examined at a magnification of 10-15x.




Component Engineering Training Course                          VF No.   143
                                        SOLDERABILITY

Acceptance criteria:

1. At least 95% covered with a continuous new solder coating.

2. Pinholes, voids, porosity, nonwetting, or dewetting must not
   exceed 5% of the total area.




Component Engineering Training Course                         VF No.   144
                                        SOLDERABILITY




Component Engineering Training Course                   VF No.   145
                                        SOLDERABILITY




Component Engineering Training Course                   VF No.   146
                                        LEAD INTEGRITY

There are various tests for determining the integrity of device leads,
  welds and seals.

1. Straight tensile loading.

2. Application of bending stresses.

3. Application of torque or twisting stresses.

4.Application of peel and tensile stresses

The individual test conditions need to be specified.


Component Engineering Training Course                          VF No.   147
                                        LEAD INTEGRITY

Failure criteria:

The components should be examined at a magnification of 10 –
  20x after the removal of stress any evidence of:

1. Breakage
2. Loosening
3. Relative motion between lead and body
4. Adhesion failure of solder pads

shall be considered a failure.



Component Engineering Training Course                    VF No.   148
                                        LEAD INTEGRITY




Component Engineering Training Course                    VF No.   149
                                        MICROSECTION

Components are microsectioned after potting in a suitable epoxy
resin so that a microscopic examination can be undertaken for the
purpose of accurately locating, identifying and characterising all the
internal structural features of the samples in order to judge any
defects against the criteria of the specification.

Typical components that require microsection are:

                                            Diodes
                                          Capacitors
                                            Relays
                                           Isolators
                                            Fuses

Component Engineering Training Course                          VF No.   150
                       MICROSECTION OF A CAPACITOR




Component Engineering Training Course                VF No.   151
                                        ESA/SCC → ESCC

Following a SCAHC recommendation produced after consultation with the
space industry, ESCC Specifications are being phased in to replace the
ESA/SCC specifications.

The ESA/SCC Generic Specifications contain five charts which are:-

Chart I Testing Levels
Chart II Final Production Tests
Chart III Burn-in and Electrical Measurements
Chart IV Qualification Tests
Chart V Lot Acceptance Tests

In ESCC Generic specifications, these will be replaced by:-

Chart F1 General Flow Chart
Chart F2 Screening Tests Chart
Chart F3 Qualification and Periodic Tests

Component Engineering Training Course                            VF No.   152
           A TYPICAL COMPONENT
         PROCUREMENT PROGRAMME




Component Engineering Training Course   VF No.   153
                    PROCUREMENT SYSTEM SELECTION

Generally, on Larger programmes, the prime contractor selects the
method by which the EEE components will be procured. The basis
for the selection will depend upon the programme cost, meeting the
agreed schedule, and compliance to the technical requirements.

Procurement possibilities are usually assessed under three
separate headings:
- Self Procurement
- Co-ordinated Procurement
- Centralised Procurement




Component Engineering Training Course                        VF No.   154
                                        SELF PROCUREMENT

Overall higher costs:

No cost sharing between contractors

MOQs

More man power required




Component Engineering Training Course                      VF No.   155
                          COORDINATED PROCUREMENT

Minimum:
Loose association of users combining procurements

Maximum:
Almost Centralised were all parts are procured through the same
system to the same specifications.

Control is in theory maintained by the prime contractor who would
receive schedules, specifications, non-conformances evaluation
reports and other technical input from users.




Component Engineering Training Course                       VF No.   156
                             CENTRALISED PROCUREMENT


All EEE component requirements are delivered to the Prime
contractors managements team who then consolidate the
requirements into a project procurement allocation list, which once
reviewed and approved by the Procurement Management is
passed to the Procurement agent to carry out the actual
procurement.
 If properly managed Centralised procurement offers:
 - All the advantages of minimal cost
 - Maximised control and uniform quality




Component Engineering Training Course                        VF No.   157
  COMPARISON OF THE COORDINATED AND CENTRALISED
                   APPROACHES




Component Engineering Training Course      VF No.   158
     PARTS PROCUREMENT COSTS PER SATELLITE MODEL




Component Engineering Training Course        VF No.   159
                          LEAD TIMES IN PROCUREMENT

                   Device Type            Procurement Lead Time



                     Capacitor                24 – 26 weeks

                     Connector                  24 weeks

                         Diode                  24 weeks

                           IC               Stock to 26 weeks

                         Relay                  32 weeks

                       Resistor             Stock to 12 weeks

                     Transistor                 24 weeks


Component Engineering Training Course                           VF No.   160
                                 PROCUREMENT PHASES


PRE-PROCUREMENT: Those activities necessary to be
                 completed before purchase orders can be
                 placed upon the component
                 manufacturers.

PROCUREMENT:                            The actual manufacture, test and
                                         inspections necessary to meet the
                                         purchase order requirements.

POST PROCUREMENT: Those activities required to provide
                  confidence that the requirements have
                  been met and to prepare the components
                  for installation.

Component Engineering Training Course                                        VF No.   161
                        TYPICAL PROCUREMENT PHASES


    PRE-PROCUREMENT PHASE
     SELECTED PARTS
     EVALUATION PROGRAMMES
     INTEGRATE SPECIFICATIONS
     OBTAIN QUOTATION

                                        PROCUREMENT PHASE
                                                   
                          PLACE ORDERS            MANUFACTURE PARTS
                          TEST AND SCREEN         QUALIFICATION OR LAT
                          PACKAGE AND SHIP

                                                             POST PROCUREMENT PHASE
                                                              RECEIVING INSPECTION AND TEST
                                                              DESTRUCTIVE PHYSICAL ANALYSIS
                                                              KIT MARSHAL

                    6                    12             18                   24                  30
 MONTHS




Component Engineering Training Course                                                   VF No.   162
                             PRE-PROCUREMENT PHASE

The objective of this phase is to complete those activities
necessary to confidently place purchase orders for EEE
components.

Often this phase is not properly carried out, leading to severe
problems and project delays later in the programme.

Those areas most commonly neglected are:-
• Risk Management
• Component Selection
• Component Type Reduction.
• Evaluation.
• Obsolescence Management
• Specification preparation, integration and modification.

Component Engineering Training Course                         VF No.   163
                   PRE-PROCUREMENT PHASE (CONT.)

                               PPL
                                                                                                        INFORM USERS
                      USERS DRAFT PARTS LIST


           FULLY QUALIFIED            PARTIAL OR         PART TYPE REDUCTION
               PARTS                 NON-QUALIFIED            POSSIBLE?


                                                        NO              YES


                                               EVALUATION REQUIRED

                                      IDENTIFY
                                                                                REPLACE WITH
            INTEGRATE             ADDITIONAL QUAL.          NO    YES
                                                                                QUALIFIED PART
              SPECS              TESTING REQUIRED



          OBTAIN QUOTES                              SELECT MANUFACTURER(S)
                                                             & AUDIT


                                               ACCEPTABLE            UNACCEPTABLE                USER MUST REPLACE
              ORDER
                                                     CONSTRUCTIONAL ANALYSIS AND             FAIL           REJECT
                                                     ANY FURTHER EVALUATION TESTS
                             IDENTIFY
                        QUALIFICATION TEST
                          REQUIREMENTS
                                                                 PASS

                                                      PREPARE SPECIFICATION AGREE
                                                         WITH USERS/CUSTOMER




Component Engineering Training Course                                                                                VF No.   164
                                 COMPONENT SELECTION

The equipment design engineers are responsible for the selection
of EEE components. However it is the task of the component
engineers to provide support and assistance in the activity,
particularly with respect to standardization, quality and reliability
issues.

The main tool provided to assist in the selection process is the
Preferred Parts List (PPL).




Component Engineering Training Course                           VF No.   165
              THE EUROPEAN PREFERRED PARTS LIST

ECSS-Q-60-01 provides the rules for establishing the list of
preferred and suitable components to be used by European
manufacturers of spacecraft hardware and associated equipment.

A copy of the ECSS-Q-60-01 can be down loaded from the ECSS
home page (http://www.ecss.nl/)

The EPPL can be found on the ESCIES website.




Component Engineering Training Course                    VF No.   166
                                        EPPL (CONT.)




Component Engineering Training Course                  VF No.   167
                                        EPPL (CONT.)




Component Engineering Training Course                  VF No.   168
                                        EPPL (CONT.)




Component Engineering Training Course                  VF No.   169
                                        EPPL (CONT.)




Component Engineering Training Course                  VF No.   170
                                        EPPL (CONT.)




Component Engineering Training Course                  VF No.   171
                                        PPL (CONT.)

Contractual enforcement of the PPL has sometimes been
achieved, however this places a major responsibility upon the PPL
developer to ensure that the components in the PPL are:-


• Capable of satisfying a wide range of design applications
• Mature in the chosen technologies to be suitable for flight
    applications
• Considered to have a significant utilization
• Have an acceptable test or usage history
• Available from approved manufacturers



Component Engineering Training Course                           VF No.   172
                                        PPL (CONT.)

In addition to the above it is also essential that the PPL also:-

• Takes into account known single user applications

• Identifies new technologies for evaluation (Part 2)

• Is maintained and regularly updated




Component Engineering Training Course                           VF No.   173
                                        QML




Component Engineering Training Course         VF No.   174
                                        QML (CONT.)




Component Engineering Training Course                 VF No.   175
                                        QML (CONT.)




Component Engineering Training Course                 VF No.   176
                                     PARTS LIST REVIEW

Parts list should be reviewed to check:
• Availability of qualified parts.
• Lead times to component delivery.
• Part costs and minimum order quantities (MOQ)
• Part type reductions (with implicit per part cost reductions for
  buying greater quantities of a given type)
• Number of DPAs necessary - Does the EEE parts plan allow
  limited DPA on similar part types / date codes
• Radiation test requirements
• LAT levels necessary
• The need for any constructional analyses
• Evaluation plans (life test etc.)



 Component Engineering Training Course                           VF No.   177
PLASTIC ENCAPSULATED MICROCIRCUITS
               AND
   CUSTOM OFF THE SHELF DEVICES




Component Engineering Training Course   VF No.   178
                                        PEMs

Space projects are increasingly interested in using PEMs.

There are a number of reliability related issues with using COTS
PEMs for space including:

Traceability
Lot Conformance
Screening
Change Control
Radiation Hardness
Obsolescence



Component Engineering Training Course                       VF No.   179
                                        SCREENING TESTS

There are a number of tests that can be performed to increase
confidence in device reliability.

Some procurement agents believe that minimal screening is
necessary and that over and above the usual screening
requirements it is necessary to perform little more than:

Radiographic Inspection
Scanning Acoustic Microscopy (CSAM)




Component Engineering Training Course                       VF No.   180
                    SCANNING ACOUSTIC MICROSCOPY




Component Engineering Training Course              VF No.   181
                        CSAM IMAGE OF DELAMINATION




Component Engineering Training Course                VF No.   182
                   LIFTED BONDS AT THE DIE SURFACE




Component Engineering Training Course                VF No.   183
                             RADIOGRAPHIC INSPECTION




Component Engineering Training Course                  VF No.   184
                             RADIOGRAPHIC INSPECTION




Component Engineering Training Course                  VF No.   185
                                        PEMs


But…

There are other failure mechanisms and potential concerns.




Component Engineering Training Course                        VF No.   186
                                        Tg of PEM PLASTICS




Component Engineering Training Course                        VF No.   187
                                        Screening
If you need confidence approaching that which you might have from space
qualified parts you’ll need to look at performing…
DPA including Tg (Sample)
1st Electrical Test (100%)
Temperature Cycling (Sample)
Radiographic (100%)
CSAM (100%)
Electrical Test (100%)
Dynamic Burn-In (100%)
Electrical Test (100%)
Dynamic Life Test (Sample)
End Point Electrical Test(100%)
HAST (Sample)
Post HAST electrical Test (Sample)
Vibration (Sample)

Component Engineering Training Course                           VF No.   188
                        COST IMPACT OF UPSCREENING

NEPAG have produced a cost model to assess the relative costs of
buying space grade parts with the cost of upscreening COTS.

The model does not include non-recurring engineering (NRE)
charges so the model is very conservative. NRE can run to
hundreds of thousands of dollars for complex microcircuits.




Component Engineering Training Course                     VF No.   189
                   NEPAG COST MODEL PER LINE ITEM




Component Engineering Training Course               VF No.   190
                       RELIABILITY ASSURANCE LEVELS

NASA has traditionally categorized space level EEE parts by
  reliability assurance level:

Level 1 = Most reliable, intended for use in mission critical and life
  support applications (US MIL Class S, V or K or ESA Level B
  LAT2)

Level 2 = Moderate reliability for general applications (US MIL
  Class B,Q or H or ESA Level C)

Level 3 = Non-mission essential, higher risk applications (MIL-STD-
  883 Compliant)



Component Engineering Training Course                           VF No.   191
                                  IMPACT OF UPGRADING




Component Engineering Training Course                   VF No.   192
                                 RADIATION ASSURANCE

COTS parts are not designed or manufactured to meet any
particular level of radiation hardness for TID or SEE.

Radiation is a very real issue with plastic devices because plastic is
an insulator and may allow charge to build up.

Radiation Hardness Assurance a must be performed on every lot
further adding to the overall cost.

The lack of lot homogeneity for COTS may require testing of larger
samples also driving up costs.




Component Engineering Training Course                          VF No.   193
                                        CONCLUSION


COTS microcircuits are not a low cost alternative to inherently
space level parts.




Component Engineering Training Course                         VF No.   194
                                        To find out more…

NEPAG Website:
        http://eee.larc.nasa.gov/forum/default_2.htm

Mike Sampson’s paper to ESCCON 2002:
      https://escies.org/private/esccon2002/coasscopro.html




Component Engineering Training Course                       VF No.   195
                               PLASTIC DECAPSULATION




Component Engineering Training Course                  VF No.   196
                               PLASTIC DECAPSULATION




Component Engineering Training Course                  VF No.   197
                                        TYPE REDUCTION

Type reduction is carried out to minimize the number of component
types with similar functions.

Failure to carry out this activity reduces the possibility to
standardize.

This, in turn, results in significant cost increases and increased
delivery times.

It is the component engineers responsibility to ensure that this task
is carried out thoroughly.




Component Engineering Training Course                           VF No.   198
                               COMPONENT EVALUATION

ECSS-Q-60A states. If valid and acceptable qualification of a
component type cannot be demonstrated, a component evaluation
and approval testing programme shall be implemented.

This programme is required to cover the following elements:-

  -   Design and Application Assessment
  -   Constructional Analysis
  -   Manufacturer Assessment
  -   Evaluation Testing

Reduction or omission of any of the above steps may be approved
if sufficient evidence is provided to justify the omission.

Component Engineering Training Course                          VF No.   199
               DESIGN AND APPLICATION ASSESSMENT




The objective of the Design and Application assessment is to:-

• Identify those electrical parameters essential for the intended
  application

• Justify why a fully qualified component cannot be used




Component Engineering Training Course                         VF No.   200
                            CONSTRUCTIONAL ANALYSIS

Typically carried out on a sample of three representative
components, the Constructional Analysis is intended to demonstrate
that:-

• The standard of fabrication and assembly has been fully assessed.

• All potential failure modes are identified.

• No materials or processes have been employed which might result
  in premature failure of the component.




Component Engineering Training Course                      VF No.   201
          TYPICAL CONSTRUCTIONAL ANALYSIS FLOW
                                              6 OF, SAMPLES


                                           PHYSICAL DIMENSIONS


                                        ELECTRICAL MEASUREMENTS


                                        EXTERNAL VISUAL INSPECTION


                                               HERMETICITY


                                        MARKING AND SERIALISATION


                                                  X - RAY


                                               DE - CAPPING


                                        INTERNAL VISUAL INSPECTION


                                            MICROSECTIONING


                                           BOND STRENGTH TEST

                                              DIE SHEAR TEST


Component Engineering Training Course                                VF No.   202
                         MANUFACTURER ASSESSMENT


This assessment, carried out against the appropriate ESA/SCC
checklist, includes, but is not necessarily limited to, an audit of:-

• The overall manufacturing facility, and its organization and
  management.

• The manufacturers system for inspection and manufacturing
  control.

• The production line used for the component.



Component Engineering Training Course                             VF No.   203
                                 SPECIFICATION WRITING

Maximum use should always be made of existing specifications
But, projects sometimes require devices which:

-There is no existing hi-rel specification

-Require additional testing

-Testing is excessive




Component Engineering Training Course                    VF No.   204
                                 SPECIFICATION WRITING

If the required parts fall outside of existing qualification limits they
can be covered by extension and a cover sheet is all that is
required.

Specifications are prepared around the manufacturers datasheet
and sent to the manufacturer see whether the requirements are
possible and to the customer for agreement on the details. This
cycle of negotiation continues until full agreement is reached.

Specifications are usually written in the same format as some
existing specification such as those from MIL or ESA. It is
necessary to establish which type of format is most desirable to the
customer.


Component Engineering Training Course                              VF No.   205
                             OBTAINING SPECIFICATIONS

Most space specifications are available free of charge through the internet.
The following sites may prove useful:

ESA Specifications:
http//www.escies.org

US Military Specifications:
http://www.dscc.dla.mil/programs/milspec/default.asp

Military and others (J-STD, IEC etc.)
http://astimage.daps.dla.mil/online/new/




Component Engineering Training Course                                VF No.   206
                                  EVALUATION TESTING

Carried out after completion of the previously identified
assessments, evaluation testing is intended to determine which
inspection and tests are the most appropriate to provide confidence
that the component when fully meeting the procurement
specification requirements, will also meet the intended mission
requirements.

The types of testing to be considered include:-

•   Electrical stress
•   Mechanical stress
•   Environmental stress
•   Assembly capability testing
•   Radiation testing

Component Engineering Training Course                       VF No.   207
                                    EVALUATION REPORT

The Evaluation Report comprises:-

•      Design Assessment

•      Constructional Analysis

•      Manufacturer Audit

•      Evaluation test report




Component Engineering Training Course                   VF No.   208
                   PART APPROVAL DOCUMENTS (PAD)


Once the Pre-procurement technical activities are complete, it is of
great value, and mandatory for ESA programmes to summarize the
technical baseline.

The Part Approval Document (PAD), provides an excellent base for
this summary.




Component Engineering Training Course                        VF No.   209
          PART APPROVAL DOCUMENTS (PAD) (CONT.)




Component Engineering Training Course         VF No.   210
                                 ATTRITION AND SPARES

Allowance must be made for the provision of attrition and spares,
the following excerpt from a procurement plan is an example of
such a policy:-



                Total User Need            Manufacturing Attrition

                        1-2                           1
                        3-5                           2
                       5 - 500           10% or 3 whichever is greater
                        500+                         50




Component Engineering Training Course                                    VF No.   211
                         OBSOLESCENCE MANAGEMENT

How can we minimise the affects of obsolescence?

-At the design phase the selection of the components must have
the maximum predictable life span.

-Procure sufficient components for the intended programme and
any envisaged ‘follow on’ programmes

-Monitor the availability of components used in the design and
allow the implementation of ‘last time buy’

-Joining obsolescence groups can yield opportunities to discuss
‘work around solutions’ with other engineers

Component Engineering Training Course                        VF No.   212
                OBSOLESCENCE MANAGEMENT (CONT.)

-    There are manufacturers who specialise in buying die stock
     from manufacturers who are phasing out product types.

-    Assembly and Test Houses can package and screen product if
     die is available.




Component Engineering Training Course                        VF No.   213
                               RISK MANAGEMENT




Component Engineering Training Course            VF No.   214
                           RISK MANAGEMENT CONCEPT

Risk management is a four step systematic and iterative process
for optimising resources in accordance with the project’s risk
management policy.

Four Steps:

Step1 - Define risk management implementation requirements
Step2 - Identify and assess the risks
Step 3 - Decide and act
Step 4 - Monitor, communicate and accept risks




Component Engineering Training Course                      VF No.   215
    STEP 1 – DEFINE RISK MANAGEMENT IMPLEMENTATION
                       REQUIREMENTS

              SEVERITY CONSEQUENCE SCORING SCHEME




Component Engineering Training Course               VF No.   216
    STEP 1 – DEFINE RISK MANAGEMENT IMPLEMENTATION
                       REQUIREMENTS

                             LIKELIHOOD SCORING SCHEME




Component Engineering Training Course                    VF No.   217
                    EXAMPLE OF A RISK INDEX SCHEME




Component Engineering Training Course                VF No.   218
                   STEP 2: IDENTIFY AND ASSESS RISKS

Purpose:
To identify each of the risk scenarios, to determine based on the
output of step 1, the magnitude of the individual risks and finally, to
rank them. Data from all project domains are used (managerial,
programmatic, technical)




Component Engineering Training Course                           VF No.   219
                                STEP 3: DECIDE AND ACT

Purpose:
To analyse the acceptability of risks and risk reduction options
according to the risk management policy, and to determine the
appropriate risk reduction strategy.

-Determine measures for reducing the risk
-Determine the risk reduction success/failure criteria.
-Select the best risk reduction measure




Component Engineering Training Course                         VF No.   220
      STEP 4:MONITOR, COMMUNICATE AND ACCECPT

Purpose:
To track, monitor, update, iterate and communicate risks and finally
to accept the risks.

Periodic assessment of risks

Illustration of risk trend over project evolution

Implementation of new risks as they arise or become evident




Component Engineering Training Course                         VF No.   221
                             EXAMPLE OF A RISK TREND




Component Engineering Training Course                  VF No.   222
                           READY TO ORDER




Component Engineering Training Course       VF No.   223
                                  THE PURCHASE ORDER




Component Engineering Training Course                  VF No.   224
                    PERFORMANCE OF AN
                        INSPECTION




Component Engineering Training Course   VF No.   225
                             PLANNING OF INSPECTIONS


- Ensure that the manufacturer knows that you are coming and that
  he is aware of the exact purpose of the of the inspection

- Check that all essential documents are available.

- If previous history files are available, check for previous problems
  found and how they were dealt with. It is important to be as
  knowledgeable as possible.




Component Engineering Training Course                          VF No.   226
              DOCUMENTARY ORDER OF PRECEDANCE

To undertake an inspection the procurers inspector should use the
following documentation. Whilst undertaking an inspection it is
possible that conflicts between documents could occur. In such
circumstances the procurer’s inspector shall take the documentary
order of precedence as indicated below:-

1.Purchase order or contract
2.Detail Specification
3.Generic Specification
4.Basic Specification
5.Other reference documents




Component Engineering Training Course                      VF No.   227
                                        SAMPLE INSPECTION

Within the ESA/SCC System sampling inspection is performed for
certain tests.

Three approaches may be found within the system:-

•     Fixed sample size
•     Sample size dependent upon lot size, and used to assess the
      lot on an AQL
•     Sample size dependent on lot size and used to assess the lot
      based upon an LTPD

Use of sampling methods is of limited statistical significance due to
discontinuous nature of space component production.

Component Engineering Training Course                          VF No.   228
                            SAMPLE INSPECTION (CONT.)

Acceptable Quality Level (AQL), example

ESA/SCC Detail specification 5101/011

Electrical measurements at high temperature

Tests to be performed on a sample basis, Inspection Level II, Table
II-a, AQL = 1.0 of MIL-STD-105, minimum 10% parts to be
measured.

Using MIL-STD-105 , lot size 450, inspection level II requires
sample size letter H, Now, using the ‘Single Sampling Plan for
Normal Inspection’
code H and AQL 1.0%, gives sample 50 accept on 1, fail on 2.


Component Engineering Training Course                       VF No.   229
                            SAMPLE INSPECTION (CONT.)
        Lot Tolerant Percentage Defects. (LTPD) Example.

        Electrical measurements at room temp. on 450 2N6033 Transistors
        ESA/SCC 5203/026 a.c. parameters sample basis LTPD 7 or less.
        Using LTPD sampling plan, lot sizes greater than 200, LTPD 7 or
        less,

        The sample size is to be a reasonable size for the lot under
        inspection. e.g. Sample size 32 accept on 0 defects.
                         Sample size 55 accept on 1 defect
        Summary           LTPD = 7
                   Sample size = 32
                Acceptance no. = 0
                 Rejection no. = 1

Component Engineering Training Course                            VF No.   230
                                 INSPECTIONS SUMMARY

•      Inspect strictly in accordance with the requirements
•      Do not allow personal feelings, lack of time or previous history
       affect your judgement.
•      Report your findings in reasonable detail .
•      Never try to correct a discrepancy, raise a non-conformance.
•      Always report the sampling plan used.
•      Obtain the manufacturers representatives signature to your
       report.
•      Never lose your temper.
•      If you cause any damage, of any sort, report it immediately.


Component Engineering Training Course                            VF No.   231
                                 QUALIFICATION TESTING

 Qualification Testing of a component must be in accordance with
 Chart IV of the relevant ESA/SCC Generic Specification.

 The Qualifying Space Agency may accept relevant and recent valid
 test data as replacing part, or all, of the Chart IV test requirements.

 Components subjected to the qualification testing phase are
 considered as having undergone destructive testing.

 The disposition of the qualification test lot is the responsibility of the
 Qualifying Space Agency.




Component Engineering Training Course                              VF No.   232
          TYPICAL FINAL PRODUCTION AND BURN-IN TESTS
              FINAL PRODUCTION TESTS                 BURN-IN AND ELECTRICAL MEASUREMENTS
              (Ref. ESA / SCC 9000 Chart II)               (Ref. ESA / SCC 9000 Chart II)
                 (For Integrated Circuits)                    (For Integrated Circuits)

      Productions and Controls in accordance
      with Section 5 of the Generic Specification
                                                       Parameter Drift Values            (Initial
                                                                 Measurements)
                 Internal Visual Inspection

                                                                  Power Burn-in
                  Special In-Process Tests

                                                              Parameter Drift Values
               Final Assembly, Encapsulation                  (Final Measurements)


                     Stabilisation Bake                   Electrical Measurement at High
                                                              and Low Temperature

             Mechanical + Environmental Tests
                                                            Electrical Measurement at
                                                               Room Temperature
                    Seal Test (optional)

                                                             Radiographic Inspection
                 Electrical Measurement at
                    Room Temperature
                                                         Seal Test (Fine and Gross Leak)

              Electrical Measurement at High
              and Low Temperature (optional)                External Visual Inspection


          Marking (plus serialisation for Level B)         Check for Lot Failure (P.D.A.)


            External Visual Inspection Sampling
                   Level II - A.Q.L. 1%)                            To Figure 9


                    Dimension Check


Component Engineering Training Course                                                               VF No.   233
            TYPICAL GENERIC SPECIFICATION QUALIFICATION
                               TEST
                                                                100 Components



        Environmental / Mechanical Subgroups                   Assembly / Capability                               Endurance Subgroup
                         nnn                                       Subgroups                                        nnnnnnnnnnninnn


  15 Components                    15 Components                 15 Components                   15 Components                          15 Components



    Shock Test                    Temperature Cycling              Solderabilty                   Operating Life                High Temperature Storage



     Vibration                     Thermal Shock                  Permanence of                  Electrical Measurements         Electrical Measurements
   nnnnnnnnnnn                         nnnnn                         Marking                     during Endurance Testing        during Endurance Testing


Constant Acceleration            Moisture Resistance              Terminal Strength                 Seal Test                              Seal Test nnn



     Seal Test                        Seal Test                External Visual Inspection



Electrical Measurements at      Electrical Measurements at     Internal Visual Inspection
   Room Temperature                Room Temperature


 External Visual Inspection       External Visual Inspection     Bond Strength          (1)   External Visual Inspection         External Visual Inspection


                                                                   Die Shear      (1)

            2                                  2                            1                              1                                    1



                                          2                                                                                 1

                                                                                         3
       Component Engineering Training Course                                                                                       VF No.    234
                                   INCOMING INSPECTION

Once the devices arrives at the procurement agent. A Receiving
Inspection Record (RIR) is produced which details of the purchase
order, manufacturer, the procurement specification , lot numbers,
date codes etc.

The RIR also records:

Package inspection
Parts Inspection
Data Review
DPA Allocation

Comments, observations, NCRs etc are recorded on the RIR

Component Engineering Training Course                      VF No.   235
                                        DATA REVIEW




Component Engineering Training Course                 VF No.   236
                                        DPA

The objective of DPA is to provide an engineering evaluation of a
device lot to determine compliance with specified constructional
requirements, evaluate processes, workmanship and the material
consistency of the product.

The sample size is not statistically relevant but is intended to be a
snapshot of the quality of the lot.
A typical sample size is 3 randomly selected pieces but it can be
dependant on factors such as cost, quantity of lot and customer
requirements.




Component Engineering Training Course                           VF No.   237
                                        DPA DATA RECORDS

    Each DPA should be assigned a unique number for identification
    purposes and each component serialized if it has not been
    already.

DPA data records should include:

1. Outline of the DPA procedure.
2. DPA summary sheet.
3. DPA check list.
4. DPA data sheets.
5. Original X-rays and photographs
6. Other data or analysis results which support findings


Component Engineering Training Course                      VF No.   238
                           COMPONENT TYPES FOR DPA
DPA is required to be performed on samples from each delivered
date code of the types listed below:

                                    Discrete semiconductors
                                        Integrated circuits
                                              Filters
                                   Variable capacitors/resistors
                                       Ceramic capacitors
                                       Tantalum capacitors
                                       Relays and switches
                                             Crystals
                                             Hybrids
                                    High voltage components
                                   High frequency components
                                   Opto-electronic components


Component Engineering Training Course                              VF No.   239
    EXAMPLE DPA FLOW FOR AN INTEGRATED CIRCUIT
External visual                          MIL-STD-883 method 2009.7
Mechanical parameters                    Manufacturers data sheet
Fine leak                                MIL-STD-883 method 1014.7 cond A1
Gross leak                               MIL-STD-883 method 1014.7 cond C
Radiographic                             MIL-STD-883 method 2012
PIND                                     MIL-STD-883 method 2020
Marking permanence                       ESA/SCC 24800
Lead integrity                           MIL-STD-883 method 2004.5 cond B2
Solderability                            MIL-STD-883 method 2003.4
Internal visual                          MIL-STD- 883 method 2010.8 cond A
SEM inspection                           MIL-STD-883 method 2018.3
Wire bond strength                       MIL-STD-883 method 2011.5 cond D
Die shear strength                        MIL-STD-883 method 2019.5

 Component Engineering Training Course                               VF No.   240
                      EXAMPLE DPA FLOW FOR A DIODE


External visual                         MIL-STD-750 method 2071.4

Mechanical parameters                   MIL-PRF-19500/***

Marking permanency                      ESA/SCC 24800

Solderability                           MIL-STD-750 method 2026

Internal visual                         MIL-STD-750 method 2074.3

Microsection                            MIL-STD-750 method 2074.3




Component Engineering Training Course                               VF No.   241
                         NON CONFORMANCE CONTROL

The European Space Agency has a very precise way of dealing
with non conforming product and if it is an ESA project that is being
worked upon then it is a requirement that the ESA/SCC approach
to NCRs is followed. This is defined in ESA/SCC 22800

Many companies consider this to be too rigid and adopt a more
relaxed approach.




Component Engineering Training Course                         VF No.   242
     INITIATION OF THE ESA/SCC NON-CONFORMANCE
                        SYSTEM

There are two distinct ways of initiating the ESA/SCC Non-
Conformance System:-
   • The Chief Inspector of the ESA/SCC qualified
     manufacturers,
   • The user of the ESA/SCC Specification System,
The former is not only required to initiate the Non-Conformance
System but also to take responsibility for the initiation of the system
for any non-conformance brought to their attention from any
source.
The latter also have a major responsibility toward the system, in
that they are users of the ESA/SCC System.




Component Engineering Training Course                           VF No.   243
             THE MANUFACTURER'S CHIEF INSPECTOR

   There are clearly defined occasions when the Manufacturer's
   Chief Inspector must initiate the non-conformance procedure,
   i.e.:-

      • During final production tests.

      • As a result of a PDA failure

      • As a result of Qualification failure

      • As a result of LAT failure.




Component Engineering Training Course                   VF No.   244
                             THE ESA/SCC SYSTEM USERS
 Any person in attendance at an ESA/SCC Qualified Manufacturer's
 premises to conduct or witness a test or inspection on ESA/SCC
 qualified component lots will raise a NCCS on finding the following:

      •      Any serious breach of quality or safety procedures.
      •      Clear evidence that the Process Identification
             Document (PID) has been modified without ESA/SCC
             approval.
      •      Evidence that the lot submitted for inspection does not
             originate from the master lot identified.
      •      Should the manufacturer refuse to accept the rejection of
             any defects found.




Component Engineering Training Course                              VF No.   245
              THE ESA/SCC SYSTEM USERS (Continued)

     •      If any data to be reviewed is incomplete, inaccurate, or
            results in rejection of the data.

     •      Once components have been delivered by the component
            manufacturer to the orderer, the ESA/SCC Non-Conformance
            System, as defined within ESA/SCC 22800, shall continue to
            be applied.




Component Engineering Training Course                              VF No.   246
FLOW DIAGRAM OF NON-CONFORMANCE PROCEDURE
                NON-CONFORMANCE


         1                                    2
                     LEVEL                              Telex Notification to
                 DETERMINATION                              ESA / SCC


                                                                                                         Lot Rejection
LOCAL MRB                          ESA / SCC MRB
  Decision                            Decision:                   ESA / SCC
                                                             Documentation Affected
                                 • Reject from Lot     •                              Initiate D.C.R.
                                 Rework              •                                       nn
 Corrective                      Use”as is” (waiver)
  Action
                                                                                        D.C.R.          NO
                                                                                      decision by
                                        Distribution                                    SCCG
 Distribution
                                                                                           YES

                                   Corrective Actions
                                                                                                                Reject

 NC Closed                              NCR Closed

                                                                                         Review of
                                                                                        Qualification
                                                                                      Status by SCCG
                                  File in Qualification
                                         Report


                                                                                                             ESA / SCC QPL


Component Engineering Training Course                                                                          VF No.    247
                    NON-CONFORMANCE PROCEDURES

       • All non-conformances are notified to a Materials Review
         Board, by means of a Non-Conformance Control Sheet.

       • The Non-Conformance Control Sheet initially details the
         details of the non-conformance and, later, analysis of the
         failure, the MRB decision and confirmation that all necessary
         actions have been carried to their conclusion.




Component Engineering Training Course                           VF No.   248
Component Engineering Training Course   VF No.   249
Component Engineering Training Course   VF No.   250
                            NON-CONFORMANCE LEVELS

   There are two levels of Non-Conformance:

   LEVEL 1:                  MINOR - Any departure from the requirements
                             which can be corrected and will not contravene
                             ESA/SCC documentation.
                             MINOR Non-Conformances result in Local Material
                             Review Boards (MRB).

   LEVEL 2:                  MAJOR - All other Non-Conformances.
                             MAJOR Non-Conformances result in ESA/SCC
                             Material Review Boards (MRB).




Component Engineering Training Course                                 VF No.   251
                                        LOCAL MRB
 Local MRB shall be composed, as a minimum, of the following
 persons:-

         • Chief Inspector of the manufacturer (Chairman)

         • National Space Agency representative

         • Responsible engineer of the manufacturer

        • Representative of the Orderer (in the case of procurement)

 Members of the MRB may call in specialists as required, but they
 shall not have voting rights.




Component Engineering Training Course                           VF No.   252
                                        LOCAL MRB (CONT.)
 In determining the disposition and corrective action to be taken, the
 board shall:

      • Take all necessary action to investigate the causes of the
        non-conformance.

      • Review the records of previous actions applicable to similar or
        identical cases.

      • Consider the recommendations of specialists acting in an
        advisory capacity.

      • Initiate failure analysis of failed items, if appropriate.

      • Consider and record the effects of the non- conformance on
        contractual requirements.


Component Engineering Training Course                                VF No.   253
                                        ESA/SCC MRB

The ESA/SCC MRB shall be composed, as a minimum, of the
following persons:-

      •   National Space Agency representative (Chairman)
      •   Chief Inspector of the manufacturer
      •   Qualification Manager of the manufacturer
      •   ESA/SCC Representative having acceptance authority
      •   Representative of the Orderer (if applicable)

Members of the ESA/SCC MRB may call in specialists as required,
but these shall have no voting rights.




Component Engineering Training Course                          VF No.   254
                               NCCS RESOLUTION (CONT.)

    ACTIONS

       • Disposition for corrective action,

       • Disposition of the actual product that is the subject of
         the non-conformance (e.g. whether or not it can be of
         further use),

       • Any preventive measures taken.

    Decisions of the MRB must be unanimous.




Component Engineering Training Course                               VF No.   255
                                        NCCS CLOSE-OUT
 The last two lines on the NCCS allow for the confirmation and
 verification of the implementation of the MRB disposition.

 The NSA Inspector and the Chief Inspector shall ensure, through
 actual inspection, that all actions are completed. Close-out requires
 that, as a minimum:-

    • Corrective actions have been accomplished.

    • The effectiveness of preventive actions has been proven.

    • The necessary design or documentation changes have been
      accomplished and verified by tests if so decided by the MRB.

     • Preventive actions have been taken also in respect of identical
      material.

     • The NCCS is signed off by the Chief Inspector and the NSA
      Inspector to evidence the technical review and completion of all
      actions decided upon by the MRB.
Component Engineering Training Course                           VF No.   256
   NON-CONFORMANCE CONTROL SHEET DISTRIBUTION

    Copies are to be sent members of the relevant MRB immediately
   the “Identification” and “Description” sections have been completed
   by the Chief Inspector.

   In urgent cases, a fax or e-mail is recommended.

   After close-out by the MRB the NSA Inspector is responsible for
   defining the distribution list and for its distribution.




Component Engineering Training Course                        VF No.   257
      DISTRIBUTION OF NON-CONFORMANCE CONTROL
                     SHEET (CONT.)
   For both non-conformance levels, the standard distribution list shall
   include as a minimum:-

       • The Chief Inspector of the Manufacturer.

       • The Qualification Manager of the manufacturer.

       • The National Space Agency representative concerned.

       • ESA/SCC (level 1, for information only).

       • The National Space Agency concerned for incorporation in
         the qualification report (but only after “close-out”).

       • the Orderer (in case of procurement).

       • other persons concerned.


Component Engineering Training Course                          VF No.   258
                  SPUR’S NON CONFORMANCE REPORT




Component Engineering Training Course             VF No.   259
                               NCR – SPUR’S APPROACH

1) The NCR is raised as soon as the non conformance is
discovered with all the necessary details including which part of the
procurement specification the non conformity applies to.
2) The report is then sent to the customer and negotiation between
customer and supplier is entered into. An MRB is called if it is
considered necessary.
3)The NCR is closed out once a decision is reached to whether
they are to accept the components.

For the component supplier it is important that all NCRs are
assigned unique numbers and kept in a log along with any written
agreements between the supplier and the customer.
Copies of the NCRs must then accompany the components to the
customer.

Component Engineering Training Course                         VF No.   260
                                        ESA ALERT SYSTEM

The ESA Alert system was launched in December 1995.

This system is aimed at providing awareness of failures and
problems experienced in space projects, in order to eliminate or
minimise their impacts and prevent their recurrence in current and
future projects..

The ESA Alert System and its implementation procedure is fully
described within Q/EAS/PROC/1

Details of how to receive ESA Alerts can also be found via the
ESCIES website (www.escies.org) or go directly to:
http://www.estec.esa.nl/qq/alerts


Component Engineering Training Course                        VF No.   261
                                        ESA ALERT SYSTEM




Component Engineering Training Course                      VF No.   262
                                        ESA ALERT SYSTEM




Component Engineering Training Course                      VF No.   263
                                        ESA ALERT SYSTEM




Component Engineering Training Course                      VF No.   264
                                        ESA ALERT SYSTEM




Component Engineering Training Course                      VF No.   265
                  COMPONENT RELIFE TESTING




Component Engineering Training Course        VF No.   266
                                   COMPONENT RELIFING

If a EEE component has exceeded its shelf life a relifing procedure
can be used validate an extension to life.

Relifeing Procedure:
A set of tests performed in order to verify that the initial quality and
reliability levels have not been affected by time.

Relifing is not usually systematically applied to shelf life
components when they reach expiry date. It is initiated whenever
an intended supply arises from a batch in question at a post expiry
date.




Component Engineering Training Course                             VF No.   267
                                        RELIFING (Cont.)

The shelf life and the time that a EEE component can be used after
relifing is detailed in a number of ‘Relifing Rules’ published by a
number of organisations in the space industry such as:

ESA – PSS 01 60
Astrium – CDSP-FD012-PRE
CNES – QFT-IN-0110MM-5210-02

None of these documents are backed up their figures and rules
with consistent approach and physics.

Astrium under contract from CNES and ESA have updated the ESA
rules taking into account field-return and failure mechanism
analysis and have established a new storage and de-storage
procedure that is to be included in ECSS format.

Component Engineering Training Course                       VF No.   268
                                        RELIFING (Cont.)

The number of samples required for relifing is usually defined in the
specification and in is usually 100% or by AQL sample according to test
and component type.

Specifications and methods used during relifing should be the same as
those implemented at the initial procurement, except the most recent
update issues should be applied.

Required test vary from between specifications and component type but
typically they might be:

Electrical Parameters
External Visual Inspection
Solderability
Hermeticity

Component Engineering Training Course                              VF No.   269
                     TYPICAL TIME PERIOD DEFINITIONS


                                        T1    T2      T3       T4



    SAVERS                           10        10      3       4
                                   YEARS     YEARS   YEARS   MONTHS

CONNECTORS
    &                                6         10      4       4
ACCESSORIES                        YEARS     YEARS   YEARS   MONTHS


 ALL OTHER                           6         9       3       4
COMPONENTS                         YEARS     YEARS   YEARS   MONTHS


Component Engineering Training Course                         VF No.   270
                                        ASTRIUM STUDY I

The CNES study consisted of two elements:

Analysing >4000 batches of relifing data from Astrium.

96% of the lots exhibited no problems.
Vast majority of failures were visual discrepancies such as
corrosion on leads.
No defects resulted from a clear failure mechanism induced by
storage.
A small percentage of defects remained due to random defects
implying that it is still necessary to screen at the relife of parts.




Component Engineering Training Course                             VF No.   271
                                        ASTRIUM STUDY II

Batches of stored devices were subjected to life 3000hr life test in
order to understand some potential effects of long term storage (10
years) on reliability.

Part types tested:
Resistors: Metal Film and Power Wire-wound
Capacitors: Ceramic and Solid Tantalum
Transistors: Signal and Power Bipolar
Diodes: Zener
IC: IREG and OP AMP
Relays: Non-Latching
Inductors

None of these parts exhibited any clear reliability concern.

Component Engineering Training Course                          VF No.   272
                      RESULTS OF THE ASTRIUM STUDY

 Astrium findings are summarised as follows:

 1) No reliability issue is to be feared on relifed parts when proper
    storage conditions are in place.
    No clear effect of storage duration was found on a relifed test
    yield.

 2) Recommendation to allow a longer period of time before it
   becomes necessary to relife. This period of time is a function of
   the device type and storage class.

 3) Relifeing tests are considered necessary to sort out the low
   percentage of potentially weak parts.


Component Engineering Training Course                           VF No.   273
                                   ASTRIUM CONCLUSION

An extended period of storage is now allowed. This will give users
a better economical output keeping all reliability guarantees for
these parts.




Component Engineering Training Course                        VF No.   274
                                        NEW SPECIFICATION

Two classes of storage defined: Class A and Class B

Class B: Based on a controlled atmosphere

Class A: Based on neutral ambience or dry air




Component Engineering Training Course                       VF No.   275
  NEW SPECIFICATION – ENVIRONMENTAL REQUIREMENTS




Component Engineering Training Course       VF No.   276
  NEW SPECIFICATION:TIME PARAMETERS-DEFINITION AND
                       VALUES

T0: Original date code
T1: Maximum allowed period with no relifing control
ΔT: Maximum allowed storage period after relifing control
N: Maximum number of relifing authorised
T2: Absolute maximum storage duration

            N=1 N=2 N=…
T0→→→→T1→→ΔT→→ ΔT…→

T0→→→→→→→→→→→→→→T2

Not all relife steps are necessary.
A user can decide to only relife his parts just before they are used
i.e. before T2 is elapsed.

Component Engineering Training Course                          VF No.   277
                   TIME PARAMETERS vs. CATEGORIES.
                                 T1       ΔT        N          T2

  Category 1                  9 years   3 years     2       15 years

  Category 2                 6 Years    3 years     3       15 years


  Category 3                 Case by    3 years   Case by    Case by
                              Case                 Case     Case and
                                                            <15 years



CAT1: Generally for class A storage
CAT2: Generally for class B storage
CAT3: Case by Case




Component Engineering Training Course                           VF No.   278
              EXTRACT FROM ASTRIUM SPECIFICATION




Component Engineering Training Course              VF No.   279
       ELECTROSTATIC DISCHARGE
                (ESD)




Component Engineering Training Course   VF No.   280
                     ELECTROSTATIC DISCHARGE (ESD)

ESD is a major cause of premature failure in electronic
components

Together with Electrical Overstress (EOS) it can account for over
50% of all field failures

ESD is totally preventable if proper precautions are taken




Component Engineering Training Course                        VF No.   281
                                        WHAT IS ESD ?

Charge is stored in insulators and is dissipated upon contact with a
conductor.

Static charge build up in a typical working environment can
generate potentials ranging from 100V to 20 kV build up . If this is
then discharged through a semiconductor the burst of charge can
cause serious damage and cause the device to fail.

Components can be damaged by contact with a charged body of by
exposure to a high electric field




Component Engineering Training Course                         VF No.   282
          ELECTRICAL FIELD SURROUNDING A STATICALLY
                       CHARGED PERSON




Component Engineering Training Course             VF No.   283
                            ESD PROTECTIVE MEASURES

-    Handling and storage at RH between 45% and 55%
-    Grounding of devices, equipment and tools
-    Avoid of insulating materials that are subject to charge
     accumulation (particularly plastics)
-    Conducting work surfaces, floors and storage cabinets
-    Use of containers and packing materials with ESD protection
-    Grounding of personnel by wrist and/or heal straps
-    Nylon coats must not be worn. Untreated cotton is preferred.




Component Engineering Training Course                         VF No.   284
                     TYPICAL ELECTROSTATIC VOLTAGES

           Means of Static Generation      Electrostatic Voltages

                                              10% to 20% Relative Humidity   65% to 90% Relative Humidity



Worker at bench                                             6,000                      100



Vinyl envelopes for work instructions                       7,000                      600



Walking over Vinyl floor                                   12,000                      250



Work chair padded with polyurethane foam                   18,000                     1,500




Common poly bag picked up from bench                       20,000                     1,200




Walking across Carpet                                      35,000                     1,500




Component Engineering Training Course                                                          VF No.   285
                                TYPICAL CHARGE SOURCES

      Object or Process                               Material or Activity
        Work Surfaces                             Waxed, painted or varnished surfaces
                                                      Common vinyl or plastics

            Floors                                         Sealed concrete
                                                         Waxed, finished wood
                                                      Common vinyl tiles or sheeting

           Clothes                                   Common clean room smocks
                                                  Common synthetic personal garments
                                                       Non-conductive shoes
                                                            Virgin cotton

            Chairs                                             Finished wood
                                                                    Vinyl
                                                                 Fibreglass

    Packaging and Handling                    Common plastic - bags, wraps, envelopes
                                                     Common bubble pack, foam
                                         Common plastic trays, plastic tote boxes, vials, parts bins

 Assembly, Cleaning, Test and                                  Spray cleaners
       Repair Areas                                   Common plastic solder suckers
                                                     Solder irons with ungrounded tips
                                                    Solvent brushes (synthetic bristles)
                                                 Cleaning or drying by fluid or evaporation
                                                         Temperature chambers
                                                              Cryogenic sprays
                                                          Heat guns and blowers
                                                               Sand-blasting
                                                           Electrostatic copiers



Component Engineering Training Course                                                                  VF No.   286
                                    THE EFFECTS OF ESD




Component Engineering Training Course                    VF No.   287
                              FAILURE ANALYSIS




Component Engineering Training Course            VF No.   288
                                        FAILURE ANALYSIS

1)    Background research
2)    Avoid additional stresses when removing the component
3)    Observe proper handling
4)    Never de-lid a component until all external tests are completed.
5)    De-lid with extreme care and with the most appropriate method.
6)    Do not jump to conclusions
7)    Report findings as soon as the analysis is complete
8)    Give serious consideration to the conclusions and
      recommendations




Component Engineering Training Course                          VF No.   289
EXAMPLE OF A FAILURE ANALYSIS – CHIP RESISTORS




Component Engineering Training Course    VF No.   290
                           EXAMPLE FAILURE ANALYSIS




Component Engineering Training Course                 VF No.   291
            EXAMPLE FAILURE ANALYSIS – RADIOGRAPHIC
                          INSPECTION




Component Engineering Training Course                 VF No.   292
                           EXAMPLE FAILURE ANALYSIS




Component Engineering Training Course                 VF No.   293
                           EXAMPLE FAILURE ANALYSIS




Component Engineering Training Course                 VF No.   294
                           EXAMPLE FAILURE ANALYSIS




Component Engineering Training Course                 VF No.   295
                                        CONCLUSION

The internal close-up inspection of the failing devices showed that
the metallisation near the termination has become thin to the point
of electrical open circuit. The most likely cause of this would
appear to be Electrical Over Stress.

The point of break down occurs in the weakest area of the network
of tracks, which is where current density would be at a maximum
during operating conditions.

A similar inspection of the good parts shows no visible signs of
defect in this (or any other) area.




Component Engineering Training Course                         VF No.   296
                                        INTERMETALLICS




Component Engineering Training Course                    VF No.   297
                                        TIN WHISKERS




Component Engineering Training Course                  VF No.   298
                                        WARNING!

Due to legislative pressures in recent years, the electronics industry
is being pushed into eliminating lead from their products and
manufacturing processes. This has resulted in many manufacturers
moving towards pure tin electroplates.

But…

      PURE TIN ELECTROPLATES CAN CAUSE POTENTIALLY
        DAMAGING GROWTHS KNOWN AS TIN WHISKERS.




Component Engineering Training Course                          VF No.   299
                                 WHAT ARE TIN WHISKERS?


• ‘Hair-like’ single crystal structures that may grow from tin finished
  surfaces.

• Length: Up to 10mm (typically <1mm)

• Diameter: from 6nm to 10μm (typically ~ 1μm)

• Growth from the base not the tip

• Whisker extrusion is driven by mechanical stress relief and
  diffusion processes in the tin finish.




Component Engineering Training Course                           VF No.   300
                      EXAMPLES OF WHISKER GROWTH




Component Engineering Training Course              VF No.   301
                           SURFACE MOUNT CAPACITOR




Component Engineering Training Course                VF No.   302
                                        TIN WHISKERS




Component Engineering Training Course                  VF No.   303
     A POSSIBLE MECHANISM FOR WHISKER GROWTH

1. Substrate elements (Cu, Zn, etc.) diffuse into tin along grain boundaries
2. Intermetallic compounds (IMC) may form preferentially in the grain
boundaries
3. As a result stress builds up in the tin layer.
4. To relieve stress, whiskers extrude through ruptures in the tin oxide.




Component Engineering Training Course                                VF No.   304
    WHY SHOULD YOU BE CONCERNED ABOUT WHISKERS?

• Electrical Short Circuits
   - Permanent (if current < 10s of mA)
   - Intermittent (if current > 10s of mA)


• Metal Vapour Arc in Vacuum
   - Atmospheric pressure < ~150 torr, V> ~18V and I>10s of Amps, then
     whisker can vapourize into highly conductive plasma of tin ions.
   - Plasma can form arcs capable of carrying HUNDREDS OF AMPS
   - Arc is sustained by tin evaporated from the surrounding area


• Debris/Contamination
   - Interfere with sensitive optics
   - Cause shorts in areas remote from whisker origins


Component Engineering Training Course                            VF No.   305
                                    WHAT CAN BE DONE?

Reduction of Stress
• Hot oil reflow / hot solder dip (preferably Sn/Pb solder)
• High temperature anneal substrate and tin finish
• Underplate with diffusion resistant barrier may delay onset.

Use of Physical Barriers to Insulate against Potential Shorts
• Conformal coat or other insulating barriers
• Increased spacing of surfaces of opposite polarity > 0.5 inches

                               AVOID PURE TIN IF POSSIBLE




Component Engineering Training Course                        VF No.   306
                 SOME LIMITATIONS – HOT SOLDER DIP

Hot Solder Dip does not always allow complete coverage of
terminals to the component body.

There is a risk of heat damage to the component package and the
seals.




Component Engineering Training Course                       VF No.   307
           SOME LIMITATIONS - CONFORMAL COATING

Conformal coating reduces (but does not eliminate) rate of whisker growth
compared to an uncoated specimen.

Whiskers have grown through 0.25 mil (6μm) Uralane 5750 coating.




Component Engineering Training Course                              VF No.   308
                                 For Further Information…


NASA’s Goddard Space Flight Centre runs the
‘Tin Whisker Home Page’:

http://nepp.nasa.gov/whisker/




Component Engineering Training Course                       VF No.   309

				
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