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					EIA-576
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                                RESISTORS, RECTANGULAR, SURFACE MOUNT

                                                      PRECISION

(From Standards Proposal No. 2246, formulated under the cognizance of the EIA P-1.2 Subcommittee on Non-
Wirewound Fixed Resistors.)

1.0 SCOPE

This standard covers precision rectangular leadless discrete fixed resistors with temperature coefficients of  50
PPM/C and lower and resistance tolerances of 1%, 0.5%, 0.25% and 0.1% for use in surface mounting applications
using soldering techniques.

1.1 Typical Construction Characteristics

The termination shall include a leach-resistant barrier layer, made of nickel or an equivalent material. The barrier
layer shall be covered with a layer of solderable material.

1.2 Classification

The type designation shall be as follows:

                PRC3216                  C                    1003                 D
                 Style             Characteristic             Resistance        Tolerance
                (1.2.1)             (1.2.2)                   (1.2.3)           (1.2.4)

1.2.1 Style

The style is identified by two letters describing the type of surface mount component (Resistor Chip) followed by
four digits giving the resistor’s nominal length and width in millimeters per Table I.
1.2.2 Characteristics

The characteristic is identified by a single letter in accordance with Table II. Individual part requirements shall be
specified in Table II and the test paragraphs.

1.2.3 Resistance

The nominal resistance expressed in ohms is identified by four digits; the first three digits represent significant
figures and the last digit represents the number of zeros to follow.

When the value of resistance is less than 1000, the letter “R” shall be substituted for one of the significant digits to
represent the decimal point.

When the letter "R" is used, succeeding digits of the group represent significant figures. The resistance value
designations are shown in Table III. Zero ohm jumper chip resistors are identified by three zeros.

1.2.3.1 Standard Values
The standard values for every decade shall follow the sequence of IEC Publication 63. Refer to Table IV.

1.2.4 Resistance Tolerance

The resistance tolerance is identified by a single letter: “F” for 1%, “D” for 0.5%, “C” for 0.25% and “B” for 0.1%.
1.2.5 Resistance Range

The resistance range applicable to this standard is 10 ohms to l megohm, inclusive. Characteristics for nominal
resistance values less than 10 ohms or greater than l megohm may differ from those specified in Table II.
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                                                   TABLE I




TYPE           BODY           BODY            BODY (*)       TERM          RATED   MAX   INCH SIZE
               LENGTH (L)     WIDTH(W)        THICKNESS(H)   WIDTH(P)      POWER   CWV   (REF)
                                                                           mW
PRC0603        0.6  0.03     0.3  0.03      0.25  0.05    0.10  0.05
               .024  .001    .012  .001     .010  .002    .004  .002    50     25     0201
PRC1005        1.0  0.10     0.5  0.10      0.30  0.10    0.20  0.10
               .039  .004    .020  .004     .012  .004    .008  .004    62.5   25     0402
PRC1608        1.60  0.10    0.80  0.10     0.50  0.10    0.20  0.10
               .063  .004    .031  .004     .020  .004    .008  .004    62.5   50     0603
PRC2012        2.00  0.15    1.25  0.15     0.50  0.15    0.40  0.25
               .079  .006    .049  .006     .020  .006    .016  .010    100    100    0805
PRC3216        3.20  0.15    1.60 0.15      0.56  0.15    0.50  0.25
               .126  .006    .063  .006     .022  .006    .020  .010    125    200    1206
PRC3225        3.20  0.15    2.50  0.15     0.56  0.15    0.50  0.25
               .126  .006    .098  .006     .022  .006    .020  .010    250    200    1210
PRC5025        5.00  0.15    2.50  0.15     0.56  0.15    0.60  0.25
               .197  .006    .098  .006     .022  .006    .024  .010    500    225    2010
PRC6332        6.30  0.15    3.20 .015      0.56  0.15    0.60  0.25
               .248  .006    .126  .006     .022  .006    .024  .010    1000   250    2512

Reference: EIA PDP-100

* Dimension H includes termination solder finish

WORKING TEMPERATURE RANGE: - 55 C to + 150 C
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                                         TABLE II

CHARACTERISTICS                                        C             E                    T
RESISTANCE TEMPERATURE COEFFICIENT                   50            25                  10
(PPM/C)
RESISTANCE TOLERANCE (%)                            1.0 (F)       0.50 (D)             0.25 (C)
                                                    0.5 (D)       0.25 (C)             0.10 (B)
                                                                  0.10 (B)
MAXIMUM AMBIENT TEMPERATURE AT RATED                70              70                   70
WATTAGE (C)
MAXIMUM AMBIENT TEMPERATURE AT ZERO                 150             150                  150
WATTAGE (C)
MAXIMUM CHANGE IN RESISTANCE  (% + 0.05)
THERMAL SHOCK (3.5)                                  0.25           0.20                0.15
SHORT TIME OVERLOAD (3.6)                            0.25           0.20                0.15
HIGH TEMPERATURE EXPOSURE (3.7)                      0.50           0.30                0.20
EFFECTS OF BONDING (3.8)                             0.30           0.15                0.10
TERMINAL STRENGTH (3.9)                              0.50           0.25                0.15
MOISTURE RESISTANCE (3.10)                           0.50           0.30                0.20
LIFE (3.14)                                          0.50           0.30                0.20




                                     TABLE III

DESIGNATION OF RESISTANCE VALUES FOR E-24, 96 & 192 VALUE SERIES
DESIGNATION                                RESISTANCE OHMS
R100 to R988 inclusive                     0.1          to         .988    inclusive
1R00 to 9R88 inclusive                     1.0          to        9.88     inclusive
10R0 to 98R8 inclusive                     10.0         to       98.8      inclusive
100R to 988R inclusive                     100.0        to     988.0       inclusive
1001 to 9881 inclusive                     1,000.0      to   9,880.0       inclusive
1002 to 9882 inclusive                     10,000.0     to   98,800.0      inclusive
1003 to 9883 inclusive                     100,000.0    to  988,000.0      inclusive
1004 to 9884 inclusive                     1,000,000.0 to 9,880,000.0      inclusive
1005                                       10,000,000.0
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                                                   TABLE IV

          STANDARD RESISTANCE VALUES FOR THE E24, E96 & E192 100 TO 1000 DECADE
                             BY RESISTANCE TOLERANCE

                             All tolerances 1% (F), 0.5% (D), 0.25% (C) & 0.10% (B)
    E24        E96    E192            E96            E192            E96              E192   E96   E192
    100        100     100            178             178            316              316    562   562
    110                101                            180                             320          569
    120        102     102            182             182            324              324    576   576
    130                104                            184                             328          583
    150        105     105            187             187            332              332    590   590
    160                106                            189                             336          597
    180        107     107            191             191            340              340    604   604
    200                109                            193                             344          612
    220        110     110            196             196            348              348    619   619
    240                111                            198                             352          626
    270        113     113            200             200            357              357    634   634
    300                114                            203                             361          642
    330        115     115            205             205            365              365    649   649
    360                117                            208                             370          657
    390        118     118            210             210            374              374    665   665
    430                120                            213                             379          673
    470        121     121            215             215            383              383    681   681
    510                123                            218                             388          690
    560        124     124            221             221            392              392    698   698
    620                126                            223                             397          706
    680        127     127            226             226            402              402    715   715
    750                129                            229                             407          723
    820        130     130            232             232            412              412    732   732
    910                132                            234                             417          741
               133     133            237             237            422              422    750   750
                       135                            240                             427          759
               137     137            243             243            432              432    768   768
                       138                            246                             437          777
               140     140            249             249            442              442    787   787
                       142                            252                             448          796
               143     143            255             255            453              453    806   806
                       145                            258                             459          816
               147     147            261             261            464              464    825   825
                       149                            264                             470          835
               150     150            267             267            475              475    845   845
                       152                            271                             481          856
               154     154            274             274            487              487    866   866
                       156                            277                             493          876
               158     158            280             280            499              499    887   887
                       160                            284                             505          898
               162     162            287             287            511              511    909   909
                       164                            291                             517          920
               165     165            294             294            523              523    931   931
                       167                            298                             530          942
               169     169            301             301            536              536    953   953
                       172                            305                             542          965
               174     174            309             309            549              549    976   976
                       176                            312                             556          988
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2.0 DEFINITIONS

2.1 Wattage
Power rating is based on continuous full load operation at a rated ambient temperature of 70C. For operation at
higher ambient temperatures, resistors shall be derated in accordance with 2.1.1.

2.1.1 Derating Curve for Higher Ambient Temperatures



                       120




                       100




                       80
         % W (power)




                       60




                       40




                       20




                        0
                             -60   -40   -20    0       20       40     60     80     100   120   140   160   180

                                               Ambient Temperature in Degrees Celsius




In no case shall the maximum continuous working voltage (CWV) be exceeded.

2.2 Voltage
The rated dc continuous working voltage, or the approximate sine-wave rms continuous working voltage at
commercial line frequency, corresponds to the power rating as determined from the formula:
        E = Sq. Root of (PxR)                   where        E = Rated Voltage (in volts)
                                                             P = Rated Power (in watts)
                                                             R = Resistance (in ohms).

2.2.1 In no case shall the rated voltage be greater than the applicable maximum continuous working voltage
specified in Table I.

3.0 STANDARD TESTS
3.1 Test Groups

When tests are conducted, the standard test sequence and grouping shall be as shown in Table V.
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3.2 Standard Test Conditions

Unless otherwise specified, the atmospheric conditions at which tests are made are as follows:

         Temperature                                            25 C  3 C
         Barometric Pressure                                   30  2 inches of Hg
         Relative Humidity                                     less than 60 %
3.2.1 Mounting

a) Thermal Shock, Short Time Overload, Moisture Resistance, Terminal Strength, Temperature Coefficient and
   Load Life tests shall be performed with the units mounted resist side up by their normal means on a glass epoxy
   test substrate, FR4 or equivalent, having a thickness of 1.6 mm (0.063 in) with a surface area of at least 4 times
   the resistor surface for each unit being tested. The copper foil thickness of the test board shall be 0.035 mm
   (0.001 in.) nominal. For other tests, the resistor may be tested mounted or unmounted and pressure type contacts
   used.
b) Units shall be mounted with 60/40 or 63/37 preforms or paste. A nonactivated flux shall be used.

c) The substrate shall be placed in or on a suitable heat transfer unit (e.g. molten solder, hot plate, tunnel oven). The
   temperature of the unit shall be maintained between 215 and 260 degrees Celsius until the solder melts and
   reflows forming a homogeneous solder bond, but for no longer than 10 seconds.

   Note 1:        Flux shall be removed by a suitable solvent treatment. All subsequent handling shall be such as to
                  avoid contamination. Care shall be taken to maintain cleanliness in test chambers and during post-
                  test measurements.

3.3 Visual and Mechanical

Resistors shall be examined under appropriate magnification, 5X minimum, to verify that dimensional and physical
appearance is in accordance with the applicable requirements.

3.4 DC Resistance

The dc resistance or the equivalent percentage deviation from the specified nominal value shall be measured.

3.4.1 Measuring Apparatus

The apparatus shall have the capability of a full-scale accuracy of 0.01% on the lowest scale. The same instrument
shall be used for any one test, but not necessarily for all tests.
3.4.2 Temperature

The dc resistance test shall be performed at 25 degrees Celsius plus or minus 3 degrees.

3.4.3 Method of Contact

Resistance shall be measured by applying pressure type contacts to the termination areas of the resistor or by wire
leads on a test substrate (3.2.1) on which the resistor is mounted.
3.5 Thermal Shock

Resistors shall be tested in accordance with Method 11 of EIA Standard EIA-186. The following details and
exceptions shall apply.

a) Mounting: Resistors shall be mounted on a test substrate (3.2.1) and placed in containers which allow circulation
   of air to each resistor.

b) Measurement before cycling: Resistance shall be measured as specified in 3.4.
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c) Test Condition: Condition “C” except Step l shall be at –55 C +0/-5C and the number of cycles shall be
   500.

d) Measurement after cycling: After removal of the resistors from the chamber, the temperature of the resistors and
   the test fixture shall be stabilized at 25C  3C for a minimum of 30 minutes and the dc resistance again
   measured.
   When resistors are tested as specified, there shall be no evidence of mechanical damage and the change in
   resistance shall not exceed the value specified in Table II.


3.6 Short-Time Overload

The de resistance shall be measured as specified in 3.4. A dc test potential of 2.5 times the rated continuous working
voltage (Table II) but not to exceed twice the maximum Continuous Working Voltage (CWV) (Table I) shall then be
applied for 5 +1/-0 seconds to the resistor under the following conditions:

a) Resistors are to be mounted on a test substrate in accordance with paragraph 3.2.1.
b) Resistors are to be tested in still air with no circulation other than that created by the heat of the resistors being
   operated.
After removal of the test potential, the resistors and the test fixture shall be temperature stabilized at 25C + 3C for
a minimum of 30 minutes before again measuring the dc resistance. Resistors shall then be visually examined for
evidence of arcing, charring and burning.

When resistors are tested as specified, the change in resistance shall not exceed the value specified in Table II and
there shall be no evidence of arcing, charring or burning.

3.7 High Temperature Exposure

The resistors shall be subjected to a continuous temperature of +125C + 5C for a period of 100 hours + 4 hours in
a circulating forced air chamber. The dc resistance shall be measured in accordance with 3.4 prior to the exposure to
the high temperature. After removal of the resistors from the chamber, the resistors and the test fixture shall be
stabilized at 25C  3C for a minimum of 30 minutes and the dc resistance again measured.

The change in resistance shall not exceed the value specified in Table II

3.8 Effects of Bonding

Resistors shall be placed in a small stainless steel clip. No part of the clip jaw shall make contact with either
termination nor have sufficient tension to mechanically darnage the resistor element’s protective coating.
3.8.1 Measurement

The dc resistance shall be measured as specified in 3.4.

3.8.2 Fluxing
The specimen shall be completely immersed in flux corresponding to type L0 as specified in ANSI/J-STD-004 and
slowly withdrawn. Excess flux shall be allowed to drip off or may be wicked off with an absorbent tissue.

3.8.3 Exposure to Solder

The specimen shall be completely immersed in non-silver bearing 60/40, 63/37 or 90/10 Sn/Pb solder at 260C 
5C for 10 l seconds. Immersion shall be with the normal seating plane vertical and not less than 2 mm (0.079 in.)
below the surface of the solder meniscus, but not to a greater depth than necessary.
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3.8.4 Evaluation

After solder immersion, the specimens are to be stabilized at room temperature for a minimum of 30 minutes and the
dc resistance again measured. Resistors shall then be visually inspected for evidence of mechanical damage.

The change in resistance shall not exceed the value specified in Table II and there shall be no evidence of
mechanical damage.

3.9 Terminal Strength

a) A 76 millimeter (3 inch) piece of AWG No.26 or No.34 solid copper wire shall be soldered to each
   resistor terminal. The wires are to be soldered using a 40W iron having a tip temperature not exceeding 260C.
   The wires shall be placed along the width axis off the chip at approximately mid-width of the termination using
   60/40 solder. One wire is to be attached to the top termination on one end of the resistor, the other in the
   opposite direction on the bottom termination on the other end of the resistor.

b) A force of 20 grams shall be applied at a 90 degree angle to the surface of the chip one lead at a time for 30
   seconds. The chip shall be held with a tweezer or other suitable holding device.

c) Each termination shall be visually examined for any evidence of mechanical damage. They shall also be
   electrically examined for any evidence of discontinuity between the top and bottom termination and the resistor
   element.

Evaluation: When resistors are tested as specified, there shall be no evidence of mechanical or electrical damage to
the terminations of the resistor.

3.10 Moisture Resistance

Resistors shall be tested in accordance with Method 2 of EIA Standard EIA-186. The following details and
exceptions shall apply:

a) No initial conditioning period shall be used. DC resistance shall be measured as specified in paragraph 3.4.

b) Mounting: Resistors shall be mounted on a test board as described in paragraph 3.2.1.

c) No voltage shall be applied, no load, no polarization.

d) No measurement of dc resistance is required at the high humidity point.

e) Upon completion of Step 6 of the final cycle, the resistors shall be removed from the chamber and air-dried for
   30  15 minutes. The dc resistance shall then be measured in accordance with 3.4 and the percentage change in
   resistance between the initial and final value calculated.

When resistors are tested as specified, the change in resistance shall not exceed the value specified in Table II.

3.11 Resistance - Temperature Characteristic

Resistors shall be tested in accordance with Method 304 of MIL-STD-202. The following details and exceptions
shall apply:

a) Reference temperature: 25 C + 2 C

b) Test temperature: The high temperature shall be + 125 C and the low temperature shall be –55 C for all
   characteristics.
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c) Accuracy of temperature measurement: Resistors shall be maintained for 15 minutes within  2 C at each of the
   test temperatures.

When resistors are tested as specified, the resistance temperature characteristic shall not exceed the value specified
in Table II for the applicable characteristic.

3.12 Solderability:

3.12.1 Wetting

a) Resistors shall be placed in a small stainless steel clip or tweezers. No part of the clip jaw or tweezers shall make
contact with the surface to be evaluated.

b) The resistor shall be completely immersed in type L0 flux as specified in ANSI/J-STD-004 and slowly
    withdrawn. Any excess flux shall be removed with an absorbent pad.

c)   The test group shall be divided into three equal parts. Each group shall be completely immersed in molten
     solder of the same composition as used in the test for Effects of Bonding (3.9) at one of the temperature and
     time profiles specified in paragraph 3.12.2. Immersion shall be with the normal seating plane vertical and not
     less than 2 millimeters (0.079 in.) below the surface of tile solder meniscus, but not to a greater depth than
     necessary.

     Note:   The solder vessel should be of suitable size to contain a minimum of 2 1/2 pounds of solder All dross
             must be skimmed from the solder surface prior to the immersion of the specimen.

d) Within 60 minutes of removal from the solder bath and after the resistor has been allowed to cool to room
   temperature, flux residue shall be removed with a suitable solvent and allowed to dry.

3.12.2 Time and Temperature Profiles

a) 2 seconds immersion at 235 C  5 C

b) 3 seconds immersion at 215 C  5 C

c) 5 seconds immersion at 260 C  5 C

 Condition (a) is primarily applicable to solderability conditions associated with IR or hot air reflow soldering
  methods.

 Condition (b) is primarily applicable to solderability conditions associated with vapor-phase soldering methods,
  as the result obtained at either 235 C or 260 C is not necessarily relevant to soldering behavior at 215 C. A
  somewhat longer immersion time is specified as the wetting reaction even on a readily wetted surface can be
  expected to be slower.

 Condition (c) is primarily applicable to solderability conditions associated with immersion or wave soldering
  methods. The time-temperature relationship provides the greatest degree of assessment for dewetting.

It should be noted that, as wetting is assessed after immersion, the “dipping” method gives no measurement of the
speed of wetting; it does, however, indicate whether adequate wetting can be achieved within the specified time.

Evaluation: Units shall be visually examined under magnification to confirm a minimum coverage of 95% of clean
and smooth solder on both top and bottom surface of the wrap-around termination. The solder coated surfaces may
contain small amounts of scattered imperfections, such as pin holes, non-wetted or dewetted areas; however, these
areas shall not be concentrated in one area or on one terminal surface.
EIA-576
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3.13 Leach Resistance - Demetallization


a) Preparation: The resistors shall be prepared for solder bath immersion as specified in 3.12.1 (a) and (b).

b) Immersion: Specimen shall be immersed in molten solder as specified in 3.12.1 (c), except the immersion profile
   shall be 30  5 seconds at 260 C + 5 C.

     NOTE:        In wave soldering, the speed of dissolution of metallization is much greater than in a static dip.
                  With wave, reflow or vapor-phase soldering, the component may be subjected to subsequent
                  iron soldering for touchup repair. A long immersion at high temperature is therefore specified for
                  testing the resistance of the metallization to dissolution in molten solder.

Evaluation:

a) Areas where metallization is lost during immersion as indicated by a void in the termination surface, shall not
   individually exceed 5% of the area of any single face of the terminal area, nor collectively exceed 10% of the
   total terminal area.
b) The functional connection of the terminal area to the resistive element connection shall not be exposed.

c) Where the metallization of a terminal extends over edges onto adjacent surfaces, loss of metallization on the
   edges shall not exceed 10% of their total length.

3.14 Life

Resistors shall be tested in accordance with the following:
a) Mounting: Resistors shall be mounted on a test board as specified in 3.2.1.

b) Measurement before test: Prior to the start of the test, the dc resistance shall be measured as specified in 3.4.

c) Measurements: At the option of the tester, dc resistance measurement may be performed at the elevated ambient
   temperature (see (d) below). The initial dc resistance measurement shall be performed after stabilization and
   within 8 hours of placement in the chamber.

d) The test temperature shall be 70 C ambient forced circulating air. The test specimen, however, shall be baffled
   so as not to be subjected to direct air-flow.

e) Operating Conditions - Rated dc continuous working voltage shall be applied intermittently for 1.5 hours on, 0.5
   hour off.

f)   Measurements during test -- The dc resistance shall be measured at 100  4, 500  8, and 1000  24 hours and
     the change in resistance calculated. Measurements may be taken in or out of the chamber, but all measurements
     must be made under the same conditions.

Evaluation: When resistors are tested as specified, there shall be no evidence of mechanical damage and the change
in resistance between the initial measurement and any of the succeeding measurements shall not exceed the value
specified in Table II.


3.15 Resistance to Solvents:

Resistors shall be tested for resistance to solvents in accordance with the procedures specified in Method 215 of
MIL-STD-202.
a) They shall be visually examined for evidence of damage to the marking and coating over the resistive element.
EIA-576
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4.0 QUALITY ASSESSMENT


4.1 Qualification (Certification of Design Performance)
For qualification of a style, the test group shall comprise, as a minimum, the lowest, the critical and highest value for
the style and resistance range being qualified.

For qualification, a complete test sequence consisting of all the tests of Table V shall be conducted and the
acceptability levels complied with.

4.2 Quality Assurance Requirements:

The testing listed below shall be conducted on an ongoing basis in order to verily the continued acceptability of the
resistor performance. Where approved by the qualifying activity, the use of process control techniques may be
substituted for some of the verification tests.

The manufacturer shall prepare a test plan that describes the procedure to be used for test sampling and should
include the frequency and resistance values of decades to be tested.

4.2.1 Group A: Tests listed under Group I of Table V are to be conducted on samples used for Groups II, III, IV and
     IX.

4.2.2 Group B: Tests listed under Groups III through IX of Table V, shall be conducted as required for
    quality/performance audits, but not less frequently than monthly for Groups V and VI, quarterly for Group VIII,
    semiannually for Group VII and annually for Groups III, IV and IX.

4.2.3 Group C: Tests listed under Group II of Table V, shall be conducted on a semiannual basis.

4.2.4 A complete product evaluation consisting of all of Table V groups shall be conducted for qualification.
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                                             TABLE V
                           TEST SEQUENCE AND ACCEPTABILITY LEVELS



EXAMINATION/TEST                                     TEST METHOD           # UNITS/STYLE            ACC/REJ
GROUP I
Visual & Mechanical                                         3.3                   120                   0/1
DC Resistance                                               3.4
GROUP II
Resistance-Temperature Characteristic                       3.11
Thermal Shock                                               3.5                    30                   0/1
Short-Time Overload                                         3.6
GROUP III
Moisture Resistance                                         3.10                   30                   0/1
GROUP IV
Life                                                        3.14                   30                   0/1
GROUP V
Solderability                                               3.12                   36                   0/1
Resistance to Solvents                                      3.15
GROUP VI
Leaching                                                    3.13                   30                   0/1
GROUP VII
Effects of Bonding                                           3.8                   30                   0/1
GROUP VIII
Terminal Strength                                            3.9                   30                   0/1
GROUP IX
High Temperature Exposure                                    3.7                   30                   0/1

* NOTE: Number of units per Group are the minimum acceptable to statistically support reliability. When more
        than one value is tested, the test group shall be equally divided between the values, but shall have no
        fewer than 10 units per value.

				
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