MIL-PRF-39001 Capacitors, Fixed, Mica Dielectric, Established Reliability And Nonestablished Reliability, General Specification ForThis specification covers the general requirements for established reliability \(ER\) and nonestablished reliability \(non-ER\), mica dielectric, fixed capacitors \(see 6.1\). The ER capacitors have a failure rate level \(FRL\) ranging from 1.0 percent per 1,000 hours to 0.001 percent per 1,000 hours \(see 1.2.1.7\). The FRL is established at a 90 percent confidence level. The FRL, identified by the applicable symbol specified in table V is referred to operational life at full rated voltage \(see 1.2.1.6\) at 125 degrees C or 150 degrees C, as applicable. An acceleration factor of 25:1 has been used to relate the life test at 150 percent of rated voltage at rated temperature to rated voltage at rated temperature.

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MIL-PRF-39001E

4.4.1 Sample size. The number of sample units comprising a sample of capacitors to be submitted for

qualification inspection shall be as specified in table VIII, or in appendix A of this specification. The sample shall be

taken from a production run and shall be produced with equipment and procedures normally used in production.

Each capacitor style shall be qualified separately.

4.4.2 Inspection routine. Sample units shall be subjected to the qualification inspection specified in table VIII, in

the order shown. All sample units shall be subjected to group I and group II tests. These sample units shall then be

divided as shown in table VIII for group III to group VI, inclusive, and subjected to the tests for their particular group.

The units subjected to life test at rated conditions shall be continued on test for 48,000 additional hours.

4.4.3 Failures. Failures in excess of those allowed in table VIII shall be cause for refusal to grant qualification

approval.

4.4.4 FRL and quality level verification.

4.4.4.1 Failure rate (FR) qualification and lot conformance FR inspection. FR qualification and lot conformance

FR inspection 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. Upon successful

completion of the 2,000-hour qualification test (group V, table VIII), those sample units which have been

subjected to rated conditions shall be continued on test for an additional period as specified in 4.7.16.3.

b. Procedure II: Extension of qualification to lower FRL. To extend qualification to the P (0.1 percent), R (0.01

percent), and S (0.001 percent) FRLs, data from two or more voltages within a style and of similar

construction may be combined. For FRLs R and S, two or more styles of similar construction (see 4.6.1.1.1)

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 4.5f).

4.4.4.2 Quality level verification. The manufacturer is responsible for establishing a quality system to verify the

ppm defect level of lots that are subjected to the group A inspections. The ppm defect level can be maintained for

each specification sheet, or alternatively can combine all specification sheets. 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. Continued qualification is based on meeting the following requirements:

b. The capacitor design has not been modified.

c. Lot rejection for group A does not exceed 10 percent or one lot, whichever is greater.

d. Periodic group C inspection.

e. Verification of FRLs.

f. PPM assessment.

g. Continued qualification to non-ER (level C) shall be based upon maintenance of qualification for the ER part

FRL P.