MIL-PRF-83421 Capacitors, Fixed, Metallized, Plastic Film Dielectric, \(Dc, Ac, Or Dc And Ac\), Hermetically Sealed In Metal Cases Or Ceramic Cases, Established Reliability, General Specification ForThis specification covers the general requirements for established reliability \(ER\), metallized plastic film dielectric, fixed capacitors, hermetically sealed in metal or ceramic cases. Capacitors covered by this specification have failure rate levels \(FRL\) established in accordance with MIL-STD-690. The reliability for each level is identified by a symbol in accordance with table I. These FRLs are established at a 90 percent confidence level and maintained at a 10 percent producer\'s risk and, unless otherwise specified \(see 3.1\), are based on life tests performed at maximum rated voltage at maximum rated temperature. Unless otherwise specified \(see 3.1\), an acceleration factor of 5:1 has been used to relate life-test data obtained at 140 percent of rated voltage at maximum rated temperature, to rated voltage at maximum rated temperature \(see 6.1\). A part per million \(PPM\) quality system is used for documenting and reporting the average outgoing quality of capacitors supplied to this specification. Statistical process control \(SPC\) techniques are required in the manufacturing process to minimize variation in production of capacitors supplied to the requirements of this specification.

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MIL-PRF-83421E

TABLE IV. Sampling plans for subgroup 2.

Lot size

Sample size

100%

14 -

150

151 -

280

281 -

500

501 -

1,200

1,201 -

3,200

3,201 - 10,000

10,001 - 35,000

35,001 - 150,000

150,001 - 500,000

500,001 - Up

102

4.6.1.2.3 Subgroup 3 tests (solderability).

4.6.1.2.3.1 Inspection lot. An inspection lot for the purpose of subgroup 3 (solderability) testing shall consist of all

lots manufactured with the same diameter lead wire and offered for inspection within the same work week. Each

production lot shall be kept separate from every other lot. All samples belonging to a production lot shall be identified

to that lot. Means of identification is at the option of the manufacturer. Test samples may be selected from subgroup

1 electrical failures.

4.6.1.2.3.2 Sampling plan. A minimum of 5 pieces shall be selected randomly from each inspection lot; however,

each production lot shall be represented in the sample. If the inspection lot consists of more than 5 production lots,

then a minimum of one sample shall be selected from each production lot. If there are one or more failures, the

inspection lot shall be considered to have failed.

4.6.1.2.3.3 Rejected lots. In the event of one or more defects, the inspection lot is rejected. The manufacturer

may use one of the following options to rework the lot:

a. Each production lot that was used to form the failed inspection lot shall be individually submitted to the

solderability test as required in 4.6.1.2.3.2. Production lots that pass the solderability test are available for

shipment. Production lots failing the solderability test can be reworked only if submitted to the solder dip

procedure in 4.6.1.2.3.3b.

b. The manufacturer submits the failed lot to a 100 percent solder dip using an approved solder dip process in

accordance with appendix A. Following the solder dip, the electrical measurements required in group A,

subgroup 1 tests (dielectric withstanding voltage, insulation resistance at +25�C, capacitance, dissipation

factor and equivalent series resistance, if applicable) shall be repeated on 100 percent of the lot. The PDA

for the electrical measurements shall be as for the subgroup 1 tests. (Note: If hermetic seal is required in the

group A, subgroup 1 tests, this test shall be repeated.) Thirteen additional samples shall be then selected

and subjected to the solderability test with zero defects allowed. If the lot fails this solderability test, the lot

may be reworked a second time and retested. If the lot fails this second rework, the lot shall be considered

rejected and shall not be furnished against the requirements of this specification.

4.6.1.2.3.4 Disposition of samples. The solderability test is considered a destructive test, and samples submitted

to the solderability test shall not be supplied on the contract.