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					     GLAST LAT Project                       TKR Peer Design Review, Mar 24-25, 2003




                         GLAST Large Area Telescope
Gamma-ray Large
                         Tracker Subsystem
Area Space
Telescope
                         5B: EEE Parts and Electronic
                         Packaging


                         Nick Virmani
                         LAT EEE parts and Electronic Packaging
                         Manager

                         nvirmani@swales.com
                         (202) - 767 - 3455



5B                            Nick Virmani                                        1
         GLAST LAT Project                     TKR Peer Design Review, Mar 24-25, 2003


                               Outline

     •   EEE Parts Requirements
     •   EEE Part Implementation Plan
     •   EEE Parts Status
     •   Process Flow for ASICs and MCM Fabrication, Screening,
         and Qualification
     •   Radiation Testing
     •   Radiation testing Results
     •   Electronic Packaging Program
     •   ASIC and MCM Documentation Status
     •   EEE Parts Issues & Risk Mitigation
     •   Manufacturing and Test Process Flow of TKR Hardware




5B                              Nick Virmani                                        2
        GLAST LAT Project                          TKR Peer Design Review, Mar 24-25, 2003


                            EEE Parts Requirements

     • Requirements Summary
        – Parts screening and qualification per GSFC 311-INST-001,
          Level 2,
        – Additional requirements outlined in the LAT EEE parts
          program control plan, LAT-MD-00099-1
        – Review and approve EEE Part Lists.
        – Derate EEE Parts per PPL-21
           • Review and approve derating information before
             drawing sign-offs.
        – Perform stress analysis
        – Parts Control Board (PCB) Approach, a partnership
          arrangement with NASA/GSFC parts engineer and code
          562.



5B                                  Nick Virmani                                        3
        GLAST LAT Project                      TKR Peer Design Review, Mar 24-25, 2003


                  EEE Parts Implementation Plan
     • Part lists are reviewed and approved by the project PCB prior
       to flight procurements.
     • Special considerations include:
        – Radiation evaluation of all active components
        – Radiation testing (TID and/or SEE ) when necessary
        – Parts stress analysis
        – PIND testing on all cavity devices
        – Destructive Physical Analysis (DPA), when applicable
        – Mandatory in process inspections and verification on
           Multi-Chip Modules (MCMs) and other devices as required
        – Life Testing if Quality Conformance Inspection (QCI) data
           within one year of the lot being procured is not available
        – No pure tin, cadmium, and zinc plating is allowed
        – Vendor surveillance where required.



5B                              Nick Virmani                                        4
        GLAST LAT Project                     TKR Peer Design Review, Mar 24-25, 2003


                  EEE Parts Implementation Plan
     • Special considerations include cont’d:
        – 50V ceramic capacitors require 850C/85RH low voltage
          testing
        – Mandatory surge current testing on all tantalum
          capacitors
        – MCM testing and verification requires special evaluation
          as outlined in the EEE parts plan
        – Age control requirements. Lot Date Code (LDC) older than
          5 years requires DPA and room temperature re-screen
        – Parts traceability from procurement to assembly of board
          and components.
        – GIDEP Alerts & NASA Advisories review and disposition
          from selection of parts until subsystem integration.
        – Parts Identification list (PIL) includes LDC, MFR,
          Radiation information on the flight lot



5B                             Nick Virmani                                        5
        GLAST LAT Project                       TKR Peer Design Review, Mar 24-25, 2003


                            EEE Parts Status
     • The TKR subsystem EEE parts lists have been reviewed by
       the PCB all parts have been approved except ASIC
       screening, MCM screening, flex cable screening and
       qualification, and cristek connectors.
     • Resettable polyswitch fuse specification LAT-SS-01116-04
       was approved by the PCB and will review test data after
       completion of the tests.
     • All part test data will be reviewed prior to flight assembly by
       the PCB where applicable.
     • The goal is to approve the remaining parts on the parts lists
       prior to the CDR
     • Discuss EEE parts availability weekly, to support fabrication
       schedule.
     • Perform 100% incoming inspection as per defined
       procedures.



5B                               Nick Virmani                                        6
        GLAST LAT Project                       TKR Peer Design Review, Mar 24-25, 2003


                            EEE Parts Status

     • Performed stress analysis of most of the approved parts on
       the parts lists and they meet derating criteria after stress
       application. Will complete the remaining analysis by the CDR.
     • Perform screening and qualification tests as required per
       approved procedure.
     • Hold regular meeting with GSFC Parts Engineer to resolve
       any parts-related issues and approve parts though the Parts
       Control Board (PCB).
     • Attribute data for screening and lot specific qualification/QCI
       data shall be reviewed for acceptance of parts for flight.
     • Parts Identification List (PIL) and As-built parts lists is
       maintained and will be submitted to GSFC.




5B                               Nick Virmani                                        7
          GLAST LAT Project                                                             TKR Peer Design Review, Mar 24-25, 2003

                      Process Flow for ASICs and MCM
                   Fabrication, Screening, and Qualification
                   WAFERS
                                             Wafer Probe                                      WAFER              WAFER
                   RECEIVE
                                             100% Sort                 INSPECTION            LAPPING              SAW
                 FROM MOSIS
                                                dies                                          MOUNT            PROCEDURE
                    USING
                                                                                            PROCEDURE
                   AGILENT
                  PROCESS
                                             Wafer Probe
                                             Procedure
                    100%
                 INSPECTION




                                                                                                                PACK DIE
                                                                                                         IN WAFFLE PACK OR GEL
DPA & Scanning                                             CONTROL
                               OPTICAL                                               SAMPLE               PACK FOR SHIPPING TO
   Electron                                                MONITORS
                               QC GATE                                              RADIATION              TELEDYNE WITH DATA
  Microscope                                                 FOR
                                                                                     TESTING            PACKAGE & TRACEABILITY
    (SEM)                                                  RADIATION
  Inspection
                              2ND OPTICAL
                              INSPECTION




                                                                                                           VERIFY
                  Receive/Inspect ASIC die             Clean/Bake               BOND PITCH
                                                                                                        ADHESION AND
                   in waffle or gel packs,             PWBs as per             ADAPTER FLEX
                                                                                                         INSPECTION
                  PWBs and parts, record               NASA-STD-                  CIRCUIT
                      data at Teledyne                   8739.3




5B                                                            Nick Virmani                                                   8
     GLAST LAT Project                    TKR Peer Design Review, Mar 24-25, 2003

             Process Flow for ASICs and MCM
          Fabrication, Screening, and Qualification




5B                         Nick Virmani                                        9
          GLAST LAT Project                                                  TKR Peer Design Review, Mar 24-25, 2003

                    Process Flow for ASICs and MCM
                 Fabrication, Screening, and Qualification
        Clean Die Bonding
                                        Apply Die Attach
        Surfaces of PWB                                          COB Die Placement
                                        Material to PWB                                     Die Attach Monitor
        Plasma and Local                                           on the PWB
                                            (MCM)
          cleaning (IPA)




         Die Attach Material          Plasma Clean PWB                                     In Process Wirebond
              Cure per                  and Die Bonding            Wirebond of ASIC           Pull Testing on
           Manufacturer’s             Surfaces for Wedge          die and MCM PWB          samples and Monitor
            Suggestions                  Wire Bonding




                                Rework, if required                      100% Optical Inspection


                                        Functional Testing
                                                                   Rework or replace        Encapsulate ASIC
        Install connectors by           and verification of
                                                                    dies if required        die and bond areas
           hand-soldering                MCM as per test
                                           program *


     * Test all register and memory locations, all I/O functions, including LVDS bias levels, all inter-
     chip communication, power consumption, all amplifiers by charge injection and test the trigger
     output, and for excessive noise or instabilities.

5B                                                      Nick Virmani                                             10
      GLAST LAT Project                                               TKR Peer Design Review, Mar 24-25, 2003

                Process Flow for ASICs and MCM
             Fabrication, Screening, and Qualification
                             Full Functional
          100%                Testing using
                                                                                     Conformal Coat
        Inspection         configured software                Clean
                              test & EGSE



                                               100% Inspect


                             Pack each MCM
       Full Functional      individually in the                                        100% thermal
        Testing using      ESD container with               MCM ready                cycling –30 to +85
     configured software      pigtail hanging             functional test &             degrees C,
        test & EGSE           outside of the             environmental test              unpowered
                           container for testing




                                                          100% Dynamic
                                   100%                    burn-in at 85            Review results data
         Functional                Visual                 degrees C with                 package
          Testing                Inspection                 continuous
                                                         monitoring for 168
                                                               hours




5B                                            Nick Virmani                                                11
      GLAST LAT Project                                          TKR Peer Design Review, Mar 24-25, 2003

                Process Flow for ASICs and MCM
             Fabrication, Screening, and Qualification
                          Present data to the
                                                                                 Store MCM in
       100% Visual        Parts Control Board          Obtain approval
                                                                                 nitrogen purge
        Inspection        (PCB) Screening &              from PCB
                                                                                     storage
                              Qualification




     MCM ready for next                                                           100% powered
      step and sample       Select 38 MCMs               Radiograph 2          thermal cycling –30
        selection for      from screened lot          samples and DPA on        to +85 degrees C,
         qualification                                     1 sample                 100 cycles




                             100% Dynamic
                                                             100%              Thermal Vac testing
        100% Visual         burn-in testing for
                                                             Visual            for 10 samples, 12
         inspection             240 hours
                                                           Inspection                 cycles




5B                                          Nick Virmani                                             12
     GLAST LAT Project                                        TKR Peer Design Review, Mar 24-25, 2003

                Process Flow for ASICs and MCM
             Fabrication, Screening, and Qualification
                            100%
                                                                               Radiograph
     Vibration Testing      Visual                     Functional
                                                                              CSAM & DPA
        10 samples        Inspection                    Testing




                         PCB Approval
      Review of Data




5B                                      Nick Virmani                                              13
        GLAST LAT Project                       TKR Peer Design Review, Mar 24-25, 2003


                            Radiation Testing

     • All EEE parts are being reviewed by PCB and screened for
       radiation susceptibility against the radiation specification
       defined in GLAST IRD-433-SPEC-001.
     • Requirements:
        – Total dose requirement, including standard factor of 2
           safety margin is 4.5 Krad (Si) for 5 years behind 100 mils
           Aluminum.
        – Our goal is to test all parts up to 10 Krads (Si).
        – SEE Damage – no SEE shall cause permanent damage to
           the subsystem.




5B                               Nick Virmani                                       14
        GLAST LAT Project                            TKR Peer Design Review, Mar 24-25, 2003


                            Radiation Testing

     • SEE Rate and Effects Analysis:
        – SEE rates and effects shall take place based on threshold
          LET (LETth) as follows:
               Device Threshold                  Environment to be Assessed
     LETth < 15 MeV*cm2/mg                 Cosmic Ray, Trapped Protons, Solar
                                           Heavy Ion and Proton
     LETth =15-37 MeV*cm2/mg               Cosmic Ray, Solar Heavy Ion
     LETth > 37 MeV*cm2/mg                 No analysis required


        SEE immune is defined as a device have an LETth > 37
          MeV*cm2/mg

        – Our goal is to test each part to this specification.


5B                                Nick Virmani                                           15
        GLAST LAT Project                      TKR Peer Design Review, Mar 24-25, 2003


                       Radiation Testing Results

     • Radiation testing was performed on engineering parts
       produced using similar processes and materials.
     • An earlier version of ASICs tested and met requirements.
     • No outstanding issues




5B                              Nick Virmani                                       16
        GLAST LAT Project                     TKR Peer Design Review, Mar 24-25, 2003


                  Electronic Packaging Program

     • Electronic Packaging, Manufacturing, Test, and Process
       Control program
        – Manufacturing, Assembly, and Quality Control of electronic
          system will be in compliance to the NASA technical
          standards: NASA-STD-8739.1, NASA-STD-8739.2, NASA-
          STD-8739.3, NASA-STD-8739.4, NASA-STD-8739.7, and IPC-
          6012 & 6013.
     • Rigid MCM PWBs shall meet the requirements of LAT
       Procurement Specification, LAT-DS-01127-01 based on Mil-
       PRF-55110, Revision F, and GSFC S-312-P-003 with a
       minimum internal annular ring of 0.002”.
     • Flex circuit and cables shall meet requirement of LAT-PS-
       01132 and IPC 6013 class 3. Coupons shall be submitted to
       GSFC for evaluation.



5B                             Nick Virmani                                       17
        GLAST LAT Project                       TKR Peer Design Review, Mar 24-25, 2003


                  Electronic Packaging Program

     • PWB Coupon will be analyzed by GSFC prior to flight
       assembly.
     • Particular attention will be paid to the quality of workmanship,
       soldering, welding, wiring, marking of parts and assemblies,
       plating and painting.
     • Verification of flight hardware will be performed by NASA
       certified and qualified personnel other than the original
       operator.
     • An item inspection will be performed on each component to
       verify:
        – Configuration is as specified on each component
          drawing/specification.
        – Workmanship standards have been met.
        – Test results are acceptable


5B                               Nick Virmani                                       18
         GLAST LAT Project                         TKR Peer Design Review, Mar 24-25, 2003


            ASIC and MCM Documentation Status
     •   Wafer Procurement from MOSIS / Agilent
          – LAT-PS-1279: Overview
          – LAT-PS-1201: Front-end readout chip (GTFE) approved by PCB
          – LAT-PS-1222: Readout controller chip (GTRC) approved by PCB
          – LAT-PS-1250: wafer probing, review in process
          – LAT-PS-01321: wafer lapping, dicing, and inspection, review in
             process.
          – LAT-TD-1325: Radiation testing, to be reviewed.
     •   Several other documents such as MCM assembly, SMT assembly,
         part procurements are in draft format and shall be released by CDR.
     •   Final board prototypes were recently produced and are being
         tested:
          – PWB: loaded with parts and new ASICs for functional testing
          – Pitch Adapter: Teledyne is bonding 3 of them to MCMs to check
             that the new design works
          – Bias: sent to Italy for review

5B                                  Nick Virmani                                       19
        GLAST LAT Project                      TKR Peer Design Review, Mar 24-25, 2003


              EEE Parts Issues & Risk Mitigation
     • MCM board qualification and handling.
        – To mitigate this risk, processes, procedures, qualification
           plan, and vendor verification plan is in process and will
           ensure they are implemented successfully.
     • Pitch adapter flex gluing and alignment accuracy when
       bonding to PWB.
        – To mitigate this risk, processes will be verified and
           controls will be implemented at Teledyne.
     • Flight ASICs testing
        – To mitigate this risk, all processes and procedures are
           being approved. Test software is being improved, which
           will be used for verification.
     • MCM Assembly and Verification
        – To mitigate this risk, manufacturing readiness reviews will
           be performed and mandatory inspection points will be
           selected.

5B                              Nick Virmani                                       20
        GLAST LAT Project                      TKR Peer Design Review, Mar 24-25, 2003


              EEE Parts Issues & Risk Mitigation

     • Flex Cable to LAT-PS-01132, defines procurement and
       qualification requirements.
        – To mitigate this risk EM flex cable will be manufactured to
          this specification and will be qualified.
        – A visit to the vendor (Parlex) is planned for early April,
          together with GSFC representatives.
     • Flex Cable Assembly.
        – To mitigate risk a detailed procedure being written & EM
          flex will be assembled and will be tested prior to flight
          production.
     • Radiation Testing & Plans
        – To mitigate risk GSFC is involved in approving plans but
          radiation plans yet not approved.



5B                              Nick Virmani                                       21
        GLAST LAT Project                             TKR Peer Design Review, Mar 24-25, 2003


                                  Connectors
     • Nano-connectors: Omnetics was recently approved and the
       parts are now on order, including the connector savers.

                            On MCM


                            On cable


                                                                 Larger 080
                                                                 screws


     • Micro-D connectors: Kristek connectors are not yet approved,
       but we don’t expect any difficult issues.




5B                                     Nick Virmani                                       22
          GLAST LAT Project                       TKR Peer Design Review, Mar 24-25, 2003


                                  SMT Parts

     •   HV capacitors: Novacap
          – Procurement spec: LAT-PS-01194
          – On order for the Tracker and Calorimeter
     •   Polyswitches: Raychem (Tycho)
          – Procurement spec: LAT-SS-01116
          – A sample lot was already procured and all testing performed, so
            no surprised are expected in the flight lot
          – Recently finalized and approved, and the parts are on order
          – Long process of testing at UCSC and discussions with the vendor
              • 100% of parts: screening after thermal cycle
              • 10% of parts: more extensive tests after soldering
              • Smaller sample for qualification testing at UCSC
     •   Ceramic & tantalum capacitors: approved with no issues
     •   Resistors: approved with no issues
     •   Thermistor: approved with no issues


5B                                 Nick Virmani                                       23
           GLAST LAT Project                                                        TKR Peer Design Review, Mar 24-25, 2003

               Manufacturing and Test Process Flow
                      for Tracker Hardware
     Pre-Production                 Procurement                       Fabrication                     Assembly


 -Initial Quality Planning      -Pre-award surveys               -Manufacturing Reviews         -Work instructions,
 -Design Reviews                -Supplier Evaluation             -Work instructions and         procedures, and travellers
 -Critical Components           -Purchase Document Review        procedures                     -Audits
 -Documentation Reviews         -Source inspection where         -Calibration                   -Configuration verification
 -Lessons Learned               applicable                       -Process Readiness             -Inspection
 -Quality Criteria              -Critical Components             -Nonconforming Material
 -Design Requirements           -Nonconforming Material          Control
 -Workmanship Standard          Control                          -Inspection
 -Training and Certification                                     -Material Review Board
                                                                 -Audits




                                Integration & Test                        Storage &
                                                                          Shipping

                               -Test Readiness Review                 -Storage and Shipping
                               -Nonconforming material control        Requirements
                               - Previous Operation Audits            -Inspection and storage
                               -Component Data/Subsystem              shipping controls
                               packages                               -Data Package Reviews
                               -Test Procedures                       -Audits
                               -Test Monitoring
                               -Data Review
                               -Closeout of open NCMRs.


5B                                                        Nick Virmani                                                        24

				
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