scope:

This specification covers the general requirements for plastic (or metallized plastic) dielectric, fixed capacitors, enclosed in nonmetal cases intended primarily, in view of the limited long term moisture resistant characteristics, for use in potted or encapsulated systems, in blocking, filter and by-pass applications (see 6.4). Capacitors covered by this specification have failure rates ranging from 1.0 percent to 0.001 percent per 1,000 hours (see 1.2.1.7). These failure rate levels 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 +85°C. An acceleration factor of 5:1 has been used to relate life test data obtained at 125 percent, or 140 percent of rated voltage at +85°C to rated voltage at +85°C. The failure rate levels are based on catastrophic failures and failures occurring outside the degradation limits.

Capacitors covered by this specification shall be classified as indicated by style (see 1.2.1.1 and 3.1).

The term Part or Identifying Number (PIN) is equivalent to the term (part number, identification number, and type designator) which was previously used in this specification. A Parts 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. The PIN shall be in the following form, and as specified (see 3.1 and 3.26.1).

The style is identified by the three-letter symbol "CFR" followed by a two-digit number; the letters identify established reliability, plastic dielectric fixed capacitors in nonmetal cases. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, U.S. Army Laboratory Command (LABCON), ATTN: SLCET-R-S, Fort Monmouth, NJ 07703-5302, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

The terminal is identified by a single letter as shown in table I. TABLE I. Terminal.

Symbol Terminal -------------------------------- A Axial wire-lead R Radial wire-lead L Lugs

The characteristic is identified by a single letter as shown in table II. TABLE II. Characteristic.

Symbol Construction Operating temperature Dielectric material Electrode range -------------------------------------------------------------------------------------- K Polypropylene Foil −55°C to +105°C L Polypropylene Metallized polypropylene −55°C to +105°C M Polyethylene terephthalate Foil −55°C to +85°C N Polyethylene terephthalate Metallized polypropylene terephthalate −55°C to +85°C Q Polycarbonate Foil −5°C to +125°C 1/ R Polycarbonate Metallized polycarbonate −55°C to +125°C 1/ S Poly-para-xylylene Foil −55°C to +125°C 1/ 1/ For operation at +125°C, characteristics Q, R, and S capacitors shall be voltage derated (see table III).

The rated voltage is for operation at +85°C and is identified by a single symbol as shown in table III. TABLE III. Voltage rating at +85°C. 1/

Symbol DC voltage rating ---------------------------- A 50 B 100 C 200 D 300 E 400 F 600 G 75 H 150 J 25 K 250 L 800 1/ Voltage derating at high ambient temperatures is dependent on the characteristic as follows: Characteristics M and N are rated for +85°C operating only. The +85°C rating of characteristic Q capacitors shall be derated by one-third for operation at +125°C. The +85°C ratings of characteristics R and S capacitors shall be derated by one-half for operation at +125°C.

The nominal capacitance value, expressed in picofarads (pF), is identified by a three-digit number; the first two digits represent significant figures and the last digit specifies the number of zeros to follow.

NOTE: Tabulated capacitance values expressed in microfarads (µF) are given for information only (see 3.1).

The capacitance tolerance is identified by a single letter as shown in table IV. TABLE IV. Capacitance tolerance.

Symbol Capacitance tolerance -------------------------------- Percent (±) F 1 G 2 J 5 K 10 M 20

The failure rate Level (based on life test performed at +85°C) is identified by a single letter as shown in table V. TABLE V. Failure rate Level (established at a 90-percent confidence Level).

Symbol Failure rate level ------------------------------ Percent/1,000 hours M 1.0 P 0.1 R 0.01 S 0.001