MIL-PRF-19978 Capacitors, Fixed, Plastic \(Or Paper-Plastic\) Dielectric \(Hermetically Sealed In Metal, Ceramic Or Glass Cases\), Established And Non-Established Reliability General Specification ForThis specification covers the general requirements for established reliability \(ER\) and non-established reliability \(non-ER\), direct current \(dc\), plastic or paper-plastic dielectric, fixed capacitors, hermetically sealed in metal or ceramic or glass cases. Capacitors meeting the established reliability requirements specified herein have failure rate \(FR\) levels ranging from 1.0 percent to 0.001 percent per 1,000 hours \(see 1.2.1.9\). These FRLs are established at a 90-percent confidence level and maintained at a 10-percent producer\'s risk and are based on life tests performed at maximum rated voltage and maximum rated temperature. An acceleration factor of 5:1 has been used to relate the life test data obtained at 140 percent of rated dc voltage at the applicable high test temperature to the rated voltage at the applicable high test temperature. This specification also covers removable mounting retainers for use with applicable capacitors \(see 3.1\). A parts 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.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14

MIL-PRF-19978K

TABLE VIII. FRL substitutability.

Parts qualified to FRL

Substitutable for FRL

M, P, and R

M and P

3.30.6 Substitution of capacitance tolerance and voltage. Parts qualified and marked to tighter capacitance

tolerance or higher rated voltage, with acquiring agency approval, are substitutable for parts marked to looser

capacitance tolerance or lower rated voltage, provided all other values, such as case size, characteristic, and leads

are the same. Unless specified in the contract or purchase order (see 6.2), the substitutable parts shall not be

remarked, the lot date code on the parts are unchanged, and the workmanship criteria are met.

3.30.7 Non-ER marking. An ER part may be marked and furnished as a non-ER part if produced on the same

assembly line, and provided it is subject to and meets all the inspection requirements of the ER part.

3.31 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally

preferable materials should be used to the maximum extent possible provided that the material meets or exceeds the

operational and maintenance requirements, and promotes economically advantageous life cycle costs.

3.32. Workmanship. Capacitors and retainers shall be processed in such a manner as to be uniform in quality

and shall be free from pits, corrosion, cracks, rough edges, and other defects that will affect life, serviceability, or

appearance.

4. VERIFICATION

4.1 Classification of inspection. The inspection requirements specified herein are classified as follows:

a. Qualification inspection (see 4.4).

b. Verification of qualification (ER styles: See 4.5; non-ER: See 4.5.1).

c. Conformance inspection (see 4.6).

4.2 QPL system (applicable to ER parts only). The manufacturer shall establish and maintain a QPL system in

accordance with 3.3. Evidence of such compliance is a prerequisite for qualification and retention of qualification.

4.3 Inspection conditions. Unless otherwise specified, all inspections shall be performed in accordance with the

test conditions specified in the "GENERAL REQUIREMENTS" of MIL-STD-202.

4.3.1 Test equipment and inspection facilities. The supplier shall establish and maintain a calibration system in

accordance with ANSI/NCSL Z540-1, ISO-10012-1, or equivalent system.

4.3.2 AC measurements. Alternating-current (ac) measurements shall be made at the frequency specified. The

magnitude of the ac voltage shall be limited to 1.0 volt root-mean-square (rms). The maximum dc bias voltage shall

be 2.2 volts for all ac measurements of capacitors.

4.3.3 Reference measurements. When requirements are based on comparative measurements made before and

after conditioning, the reference measurement shall be considered the last measurement made at +25�C 5�C prior

to conditioning. Unless reference measurements have been made within 30 days prior to the beginning of

conditioning, they shall be repeated.

4.3.4 Power supply. The power supply used for life testing shall have a regulation of 2 percent or less of the

rated voltage. The power source employed for dc leakage current measurements shall be stabilized to at least 100

ppm. No voltage fluctuations shall occur during measurements that would produce a variation in the current

measurement as read with any acceptable dc leakage current tester used to test capacitors.

4.4 Qualification inspection. Qualification inspection shall be performed at a laboratory acceptable to the

Government (see 6.4) on sample units produced with equipment and procedures normally used in production.