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.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13

MIL-PRF-39001E

3.12 Solderability. When capacitors are tested as specified in 4.7.8, the dipped surface of the lead shall be at

least 95 percent covered with continuous new solder coating. The remaining 5 percent of the lead surface shall

show only pinholes or voids. These shall not be concentrated in one area. No individual view of the dipped surface

shall show less than 95 percent coverage. Bare base metal and areas where the solder dip failed to cover the

original coating are indications of poor solderability and shall be cause for failure. In case of dispute, the percent of

coverage with pinholes or voids shall be determined by actual measurement of these areas, as compared to the total

area.

3.13 Vibration. When capacitors are tested as specified in 4.7.9, there shall be no intermittent contacts of 0.5

milliseconds (ms) or greater duration, or momentary arcing, or other indication of breakdown, nor shall there be any

open-circuiting or short-circuiting or evidence of mechanical damage.

3.14 Temperature coefficient and capacitance drift. When measured as specified in 4.7.10, the temperature

coefficient and capacitance drift shall be within the limits specified in table I for the characteristic listed (see 3.1).

3.15 Thermal shock and immersion. When tested as specified in 4.7.11, capacitors shall meet the following

requirements:

a. DWV: As specified in 3.6.

b. IR: Shall be not less than 30 percent of initial requirement (see 3.9).

c. Capacitance: The capacitance change shall not exceed 1 percent or 1 pF, whichever is greater, from the

reference measurement (see 4.3.2.1).

d. DF: Shall not exceed 150 percent of the initial requirement specified in 3.11.

e. Visual examination: No visible evidence of deterioration, permanent damage to leads or case, or corrosion

on leads.

FIGURE 1. IR versus capacitance at test temperature.