scope:

This specification covers the general requirements for fixed, film, chip resistors primarily intended for incorporation into hybrid microelectronic circuits and surface mounting applications. Resistors covered by this specification will have an established reliability with life failure rates ranging from 1 percent to 0.001 percent per 1,000 hours (see 1.2.7). These failure rates are established at 60 percent confidence on the basis of life tests. The failure rate, identified by the appropriate symbol, is referred to operation at full rated voltage and rated temperature, with a permissible change in resistance of ± 2 percent as the criteria for failure. Table I provides a summary of performance characteristics for these resistors. A part per million (PPM) quality system is used for documenting and reporting the average outgoing quality of resistors supplied to this specification. Statistical process control (SPC) techniques are required in the manufacturing process to minimize variation in production of resistors supplied to the requirements of this specification.

Resistors specified herein (see 3.1) will be identified by a PIN which will consist of the basic number of the military specification sheet and a dash number. Each military specification sheet covers a different resistor style. The dash number will be coded to provide information concerning the resistor characteristic, resistance value, resistance tolerance, termination material, and life failure rate. The PIN shall be in the following form with the dash number derived as indicated:

The style (see 3.1) is identified by the two-letter symbol "RM" followed by a four digit number; the letters identify fixed, film resistors, in a flat chip configuration.

The characteristic is identified by the single letter E, H, K, or M, in accordance with table I. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: US Army Research Laboratory, ATTN: AMSRL-PS-DC, Fort Monmouth, NJ 07703-5601, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

The termination material designation will be in accordance with table II.

The nominal resistance expressed in ohms is identified by four characters consisting of three digits and a letter. The letter is used simultaneously as a decimal point, multiplier, and a resistance tolerance designator. For resistance values:

a. Greater than or equal to 1 ohm but less than 1,000 ohms, the letters A, D, G, J, and M are used to represent a decimal point, depending on the resistance tolerance (see table III).

b. Greater than or equal to 1,000 ohms but less than 1 megohm, the letters B, E, H, K, and N are used to represent a decimal point, depending on the resistance tolerance (see table III).

c. Greater than or equal to 1 megohm, the letters C, F, T, L, and P are used to represent a decimal point, depending upon the resistance tolerance (see table III). All digits preceding and following the letters (A, B, C, D, E, F, G, H, T, L, J, K, M, N, and P) of the group represent significant figures. The resistance value designators are shown in table III. Minimum and maximum resistance values will be as specified herein (see 3.1). The standard values for every decade will follow the sequence specified in table IV of MIL-R-55342 for resistance tolerances 1.0, 2.0, 5.0, and 10.0 percent. The resistance values for tolerance 0.1 percent maybe any value within the limits specified (see 3.1), but it is preferred that values be chosen from the 0.1 percent column of table IV of MIL-R-55342.

The resistance tolerance and multipliers are identified by a single letter in accordance with table V. TABLE V. Resistance tolerance and multipliers.

Resistance Multiplier Symbol tolerance (±) ------------------------------------ 0.1 X1 A 0.1 X1,000 B 0.1 X1,000,000 C 1.0 X1 D 1.0 X1,000 E 1.0 X1,000,000 F 2.0 X1 G 2.0 X1,000 H 2.0 X1,000,000 T 5.0 X1 J 5.0 X1,000 K 5.0 X1,000,000 L 10.0 X1 M 10.0 X1,000 N 10.0 X1,000,000 P

The life failure rate designation as shown in table VI is signified by a single letter (M, P, R, S), which identifies the life failure rate level for which the resistor is qualified (see 4.5 and 6.3). TABLE VI. Life failure rate level (established at 60 percent confidence).

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

This appendix details the procedure for submission of samples with related data, for qualification inspection of resistors covered by this specification. The procedure for extending qualification of the required sample to other resistors covered by this specification is also outlined herein. This appendix is a mandatory part of the specification. The information contained herein is intended for compliance.

intended Use:

Chip resistors are intended to be used in thin or thick film hybrid circuits where micro-circuitry is indicated and in surface mount applications.