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

4.4.4 Failure rate (FR) qualification. FR qualification shall be in accordance with the general and detailed

requirements of MIL-STD-690 and the following details:

a. Procedure I - Qualification at the initial FRL. Level "M" (1.0 percent) of FRSP-90 shall apply. Sample units

shall be subjected to the qualification inspection specified in group VII, table II (see 4.4.2). The entire life test

sample shall be continued on test to 10,000 hours as specified in 4.7.24.2.2, upon completion of the 2,000

hour qualification.

b. Procedure II - Extension of qualification to lower FRLs. To extend qualification to the "R" (0.01 percent) and

"S" to (0.001 percent) FRLs, data from two or more styles within a specification sheet may be combined.

c. Procedure III - Maintenance of FRL qualification. Maintenance period B of FRSP-10 shall apply. Regardless

of the number of production lots produced during this period, the specified number of unit hours shall be

accumulated to maintain qualification. See 4.6.2.1.1 for maintenance of MIL-PRF-83421/2 styles.

4.4.5 Quality level verification. The manufacturer is responsible for establishing a quality system to assess the

ppm defect level of lots that are subjected to the subgroup 2 tests of the group A inspections. The ppm defect level

shall be maintained for each specification sheet. The ppm defect level shall be based on a 6 month moving average.

4.5 Verification of qualification. Every 6 months, the manufacturer shall provide verification of qualification to the

qualifying activity. Continuation shall be based on meeting the following requirements:

b. The capacitor design has not been modified.

c. Lot rejection for group A inspection does not exceed 5 percent or one lot, whichever is greater.

d. The requirements for group B inspection are met.

e. Verification of FRLs.

f. PPM assessment.

In the event that there is no production of a single style device during a maintenance period and the manufacturer is

listed for more than one style on the QPL, the manufacturer shall certify that they retain the capabilities and facilities

necessary to produce that product. However, the manufacturer shall still maintain the required number of unit hours

in the maintenance period using those styles produced in order to remain qualified to the applicable failure rate levels.

In the case where the lowest failure rate for an un-produced style is M, styles need not be manufactured for testing

only but the manufacturer must certify that the capability and facilities needed to produce that style are still in place.

In the event that units must be built for the purpose of maintaining the required hours, they shall also undergo all

required testing prior to being placed on life test. If during three consecutive reporting periods there has been no

production of a given style, the manufacturer may be required, at the discretion of the qualifying activity, to submit a

newly-produced (not from stock) representative product of that style to testing.

4.6 Conformance inspection.

4.6.1 Inspection of product for delivery. Inspection of product for delivery shall consist of group A inspection.