MIL-PRF-20 Capacitor, Fixed, Ceramic Dielectric \(Temperature Compensating\), Established Reliability And Non-Established Reliability, General Specification ForThis specification covers the general requirements for established reliability \(ER\) and non-ER, temperature compensating, fixed capacitors for use primarily where compensation is necessary for circuit applications due to temperature changes, in bypass and coupling applications. Capacitors meeting the ER requirements specified herein have a failure rate level \(FRL\) ranging from 1.0 percent per 1,000 hours to 0.00l percent per 1,000 hours. These failure rate levels are established at a 90-percent confidence level based on the life test parameters specified and are maintained at a 10-percent producer\'s risk. An acceleration factor of 8:1 has been used to relate the life test data at 200 percent of rated voltage at the applicable high test temperature to the rated voltage at the applicable high test temperature. A part per million \(ppm\) quality system is used for documenting and reporting the average outgoing quality of ER capacitors supplied to this specification. Statistical process control \(SPC\) techniques are required in the manufacturing process to minimize variation in production of ER capacitors supplied to the requirements of this specification.

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MIL-PRF-20M

c. Dissipation factor: Shall not exceed initial requirement.

d. Dielectric withstanding voltage: As specified in 3.9.

e. Insulation resistance: Not less than 50 percent of the initial requirement.

3.16 Terminal strength. When capacitors are tested as specified in 4.7.12, the terminals shall not loosen or

rupture, and there shall be no other damage to the terminals or capacitor body.

3.17 Resistance to soldering heat. When tested as specified in 4.7.13, capacitors shall meet the following

requirements:

a. Insulation resistance at +25�C: Unless otherwise specified (see 3.1), not less than the initial +25�C

requirement.

b. Capacitance: Shall not change more than �3.0 percent from the initial measured value.

c. Dissipation factor: Shall not exceed the initial requirements.

3.18 Moisture resistance. When tested as specified in 4.7.14, capacitors shall meet the following requirements:

a. Visual examination: No evidence of corrosion or mechanical damage.

b. Capacitance: Change not to exceed �3 percent or �0.5 pF (�0.25 pF for values less than 10 pF), whichever is

greater, from initial measured value obtained as specified in 4.7.3.

c. Dielectric withstanding voltage: As specified in 3.9.

d. Insulation resistance: Not less than 30 percent of the initial requirement.

3.19 Solderability. When capacitors are tested as specified in 4.7.15, the dipped surface of the leads shall be at

least 95 percent covered with a new, smooth, solder coating. The remaining 5 percent may contain only small

pinholes or rough spots; these shall not be concentrated in one area. In case of dispute, the percent of coverage with

pinholes or rough spots shall be determined by actual measurement of these areas, as compared to the total area.

3.20 Resistance to solvents (ink marking only). When capacitors are tested as specified in 4.7.17, there shall be

no evidence of mechanical damage and the marking shall remain legible.

3.21 Radiographic inspection (for qualification and FRL "S"). When capacitors are tested as specified in 4.7.18,

radiographic examination shall not disclose evidence of improperly made connections, substandard soldering or

structural weakness, or attached solder particles or slivers.

3.22 Fungus. The manufacturer shall certify that all external materials are fungus resistant or shall perform the

test as specified in 4.7.19. When capacitors are tested as specified in 4.7.19, there shall be no evidence of fungus

growth on the external surface.

3.23 Life (at elevated ambient temperature). When tested as specified in 4.7.20, capacitors shall meet the

following requirements:

a. Visual examination: No evidence of corrosion or mechanical damage.

b. Capacitance: Shall not change more than �3.0 percent or �0.5 pF (�0.25 pF for values less than 10 pF),

whichever is greater, from the initial value obtained as specified in 4.7.3.

c. Dissipation factor: Shall not exceed initial requirement.

d. Insulation resistance: Shall not be less than 50 percent of the initial requirement.