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

3.4.2.3 Solder dip/retinning options. The manufacturer (or authorized category B or category C distributor) may

solder dip/retin as follows (see 3.4.2.1):

a. As a corrective action if the lot fails the group A solderability test.

b. After the group A inspection has been completed, following the solder dip/retinning process, the high voltage

stabilization, DWV, IR, capacitance, and DF measurements shall be performed on 100 percent of the lot.

The percent defective allowable (PDA) for the electrical measurements shall be as for the subgroup 1 tests.

Following these tests, the manufacturer shall submit the lot to the group A solderability test as specified in

4.7.8.

3.5 Interface and physical dimensions. Capacitors shall meet the interface and physical dimensions specified

(see 3.1).

3.5.1 Pure tin. The use of pure tin, as an undercoat or final finish, is prohibited both internally and externally. Tin

content of capacitor and solder shall not exceed 97 percent, by mass. Tin shall be alloyed with a minimum of 3

percent lead, by mass (see 6.9).

3.6 DWV. Capacitors shall withstand the direct-current (dc) potential specified in 4.7.2 without damage, arcing, or

breakdown.

3.7 High voltage stabilization. When capacitors are tested as specified in 4.7.3, there shall be no evidence of

damage, arcing, or breakdown; and the IR shall be not less than the applicable value specified on figure 1 or in table

VI.

3.8 Barometric pressure (for qualification only). Capacitors shall withstand the dc potential specified in 4.7.4

without damage, arcing, or breakdown.

3.9 IR (see 4.7.5).

3.9.1 At room ambient temperature. When measured as specified in 4.7.5.1, the IR shall be not less than the

applicable value specified on figure 1 or in table VI.

3.9.2 At high ambient temperature. When measured as specified in 4.7.5.2, the IR shall be not less than the

applicable value specified on figure 1 or in table VI.

TABLE VI. IR.

Capacitance rating

Minimum IR

At 25C

0 pF to 10,000 pF

100,000 megohms

10,000 pF and greater

1,000 megohms-microfarads 1/

At 125C

0 pF to 3,300 pF

10,000 megohms

3,300 pF and greater

33 megohm-microfarads

At 150C

0 pF to 1,500 pF

5,000 megohms

1,500 pF and greater

7.5 megohm-microfarads

1/ Product obtained by multiplying the capacitance in microfarads

by the IR in megohms.

3.10 Capacitance. When measured as specified in 4.7.6, the capacitor shall be within the tolerance shown in the

type designation (see 3.1).

3.11 DF. When measured as specified in 4.7.7, the DF shall not exceed the applicable value shown on figure 2.