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.

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

MIL-PRF-83421E

4.7.3 Dielectric absorption (when specified, see 3.1 and 3.7). The capacitor shall be charged at dc rated voltage

or 100 volts dc (whichever is less) for a minimum period of 5 minutes. The initial surge current shall not exceed 50

milliamperes. A typical test schematic is shown in figure 1. At the end of this period, the capacitor shall be

disconnected from the power source and discharged through a 5 ohm �1 percent resistor for 5 �0.5 seconds. The

discharge resistor shall be disconnected from the capacitor at the end of the 5 second discharge period; and after 1

minute, the voltage remaining on the capacitor (recovery voltage) shall be measured with an electrometer, or other

suitable device having an input resistance of 10,000 megohms, or greater. The dielectric absorption shall be

computed from the following formula:

Where:

Dielectric absorption (percent).

Maximum recovery voltage.

Charging voltage.

E = DC rated voltage or 100 volts dc, whichever is less (�2 percent)

R1 and R2 = 1000 ohms �20 percent (this value not critical).

R3 = 5 ohms �1 percent.

R4 = 10,000 megohms, minimum.

Suggest use of �1230A GR electrometer or equivalent with 10,000 megohms, minimum, input resistance.

NOTES:

1. Charge for 5 minutes �10 seconds with switch in position 1.

2. Switch in position 2 for 5 seconds �0.5 seconds.

3. Switch in position 3.

4. After 1 minute read recovery voltage and compute as a percentage of charge voltage.

5. Switch to position 4, discharge and remove.

FIGURE 1. Typical dielectric absorption test schematic.