MIL-PRF-22684 Resistors, Fixed, Film \(Insulated\) General Specification ForThis specification covers the general requirements for insulated, film, fixed resistors of 2- and 5- percent resistance tolerance. These resistors are capable of full-load operation at an ambient temperature of 70 degrees C and have a resistance-temperature characteristic of +200 parts per million per degree Celsius \(ppm/degrees C\), \(see 6.1\). Designers are CAUTIONED on using these resistors in high power pulse applications \(see 6.10\).

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MIL-PRF-22684F

3. REQUIREMENTS

3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with the

applicable associated specification sheet. In the event of any conflict between the requirements of this specification

and the applicable associated specification sheet, the latter shall govern (see 6.2)

3.2 Qualification. Resistors furnished under this specification shall be products which are qualified and have been

listed on or approved for listing on the applicable qualified products list (see 4.4 and 6.3).

3.3 Material. The material shall be as specified herein. However, when a definite material is not specified, a

material shall be used which will enable the resistors to meet the performance requirements of this specification.

Acceptance or approval of any constituent material shall not be construed as a guarantee of the acceptance of the

finished product.

3.4 Interface and physical dimension requirements. Resistors shall meet the interface and physical dimension

requirements as specified (see 3.1). Each resistor shall consist of a film-type resistance element protected against

exposure to humidity and temperature conditions by an enclosure or a coating of moisture-resistant, insulating

material.

3.4.1 Coating of terminals. At the option of the contractor, the terminals may be solder coated or otherwise treated

to meet the solderability requirements. When a tin-lead solder coating is used, the tin content shall range between 40

and 70 percent.

3.4.2 Solder dip (retinning) leads. Only the manufacturer or his authorized MIL-PRF-39017 category B or C

distributor who has been previously approved may solder dip/retin the leads of the product supplied to this

specification provided the solder dip/retin process (see Appendix A) has been approved by the qualifying activity.

3.4.3 Pure tin. The use of pure tin, as an underplate or final finish is prohibited both internally and externally. Tin

content of resistor components and solder shall not exceed 97 percent, by mass. Tin shall be alloyed with a minimum

of 3 percent lead, by mass (see 6.9).

3.5 Power rating. Resistors shall have a power rating as specified (see 3.1), based on continuous full-load

operation at an ambient temperature of 70�C. This power rating is dependent on the ability of resistors to meet the

life requirements specified in 3.17. For temperatures in excess of those specified above, the load life shall be derated

in accordance with figure 1 (see 6.4).

FIGURE 1. Derating curve for high ambient temperatures.