MIL-PRF-39017 Resistors, Fixed, Film \(Insulated\), Nonestablished Reliability, And Established Reliability, General Specification ForThis specification covers the general requirements for nonestablished reliability \(non-ER\) and established reliability \(ER\), insulated, film, fixed resistors. These resistors are capable of full load operation at an ambient temperature of 70 Degrees C and have a resistance temperature characteristic of 100 parts per million \(PPM\) and 350 PPM per degree Celsius \(PPM/Degrees C\). The ER resistors have life failure rate \(FR\) levels ranging from 1.0 percent to 0.001 percent per 1,000 hours \(see 1.2.1.4\). These FR levels are established at a 60 percent confidence level on the basis of life tests. Designers are CAUTIONED on using these resistors in high power pulse applications \(see 6.13.2\).

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MIL-PRF-39017G

4.8.18 Life (see 3.24). Resistors shall be tested in accordance with method 108 of MIL-STD-202. The

following details and exceptions shall apply:

a. Method of mounting: Resistors shall be mounted on lightweight terminals. The effective length of

each lead shall be 0.5 inch minimum. Resistors shall be soldered to the terminals. Resistors

shall be so arranged that the temperature of any one resistor shall not appreciably influence the

temperature of any other resistor.

b. Test temperature: 70�C +15�C, -5�C.

Initial measurement: Measurements may be made inside or outside the chamber.

(1) Inside the chamber: When measurements are to be made inside the chamber, the initial dc

resistance shall be measured after mounting at the applicable test temperature after

temperature stabilization and within 8 hours of exposure of the resistors to the test

temperature. This initial measurement shall be used as the reference temperature for all

subsequent measurements under the same conditions.

(2) Outside the chamber: When measurements are to be made outside the chamber, the initial

dc resistance shall be measured after mounting at room temperature. This initial

measurement shall be used as the reference temperature for all subsequent measurements

under the same conditions.

d. Operating conditions: Rated dc continuous working voltage (RCWV), or filtered or nonfiltered full-

wave rectified ac voltage shall be applied intermittently, one and one-half hours "on" and one-half

hours "off" for the applicable number of hours (see 4.8.18f) and at the applicable test

temperature. "On time" shall be three-fourths of the total elapsed time. Voltage shall be

maintained within 5 percent of RCWV.

e. Test condition: 2,000 hours elapsed time for qualification with all samples continued to 10,000

hours; 10,000 hours for FR level inspection of group C.

Measurements during test:

(1) Qualification inspection: DC resistance shall be measured at the end of the 0.5 hour "off"

periods after 250 hours +72 hours, -24 hours; 500 hours +72 hours, -24 hours; 1,000 hours

+72 hours, -24 hours; and 2,000 hours +96 hours, -24 hours have elapsed.

(2) Extended life testing: DC resistance shall be measured at the end of the one-half hour "off"

periods after 250 hours +72 hours, -24 hours; 500 hours +72 hours, -24 hours; 1,000 hours

+72 hours, -24 hours; 2,000 hours +96 hours, -24 hours, and every 2,000 hours +96 hours,

-24 hours thereafter, until the required 10,000 +120, -0 hours, have elapsed. Measurements

shall be made as near as possible to the specified time but may be adjusted so that

measurements need not be made during other than normal working days.

(3). Measurements outside of chamber: When measurements are made outside the chamber,

resistors shall be outside of the chamber for a minimum of 45 minutes and stabilized at room

temperature before measurement.

g. Examination after test: Resistors shall be examined for evidence of mechanical damage.