MIL-PRF-914 Resistor Networks, Fixed, Film, Surface Mount, Nonestablished Reliability, And Established Reliability, General Specification ForThis specification covers the general requirements for nonestablished reliability \(non-ER\) and established reliability \(ER\), hermetically sealed \(see 3.27\) and nonhermetically sealed networks \(see 3.27.1\). These networks consist entirely of fixed, film resistors. They are primarily intended for use in surface mount applications where space is a major concern. ER resistors covered by this specification will have life failure rates \(FR\) ranging from 1 percent to 0.001 percent per 1,000 hours \(see 1.2.1.7\). The ER FR are established at a minimum 60-percent confidence level on the basis of life tests. Designers are CAUTIONED on using these resistors in pulse applications \(see 6.4.4\).

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MIL-PRF-914C

Operating conditions: Rated dc continuous working voltage, filtered or nonfiltered full-wave rectified ac

voltage shall be simultaneously applied to each resistor in the network intermittently, one and one-half hours

"on" and one-half hour "off", for 100 hours �4 hours and at the test temperature. During the "on" cycle, the

voltage shall be regulated and controlled to maintain 5 percent of the rated continuous working voltage.

Unless otherwise specified, power applied shall be 1.5 times the rated power (see 3.1) not to exceed the

maximum voltage.

Measurements after test: Following a minimum one-half hour stabilization period, dc resistance shall be

measured as specified in 4.8.5.

Inspection after test: Networks shall be inspected for evidence of mechanical damage.

4.8.5 DC resistance (see 3.10). The dc resistance shall be measured in accordance with method 303 of

MIL-STD-202. The following details and exceptions shall apply:

Mounting: As specified in 4.8.1, method A.

Measuring apparatus: Different types of measuring test equipment (multimeters, bridges, or equivalent) are

permitted to be used on the initial and final readings of this test, provided the equipment is the same style,

model, or if it can be shown that the performance of the equipment is equivalent or better.

Measurement energy for electronic test equipment: The measurement energy applied to the unit under test

shall not exceed 10 percent of the 25OC rated wattage times 1 second.

Test voltage for bridges: Measurements of resistance shall be made using the test voltages specified in

table XVIII. The test voltage chosen, whether it be the maximum or a lower voltage which would still provide

the sensitivity required, shall be applied across the terminals of the resistor. This same voltage shall be

used whenever a subsequent resistance measurement is made.

Temperature: Unless otherwise specified herein, the temperature at which subsequent and final resistance

measurements are made in each test shall be within �2OC of the temperature at which the initial resistance

measurement was made.

TABLE XVIII. Standard dc resistance test voltages.

Maximum test voltage (in volts)

Nominal Resistance

25 to 99

100 to 225

(in ohms)

milliwatts

98.8

0.3

0.5

1.0

100

988

1.0

1,000

9,880

3.0

10,000

98,800

10.0

100,000

and above

30.0

Procedure: Unless otherwise specified (see 3.1), all resistor elements that can be isolated in the network

shall be individually measured. All resistor elements that cannot be isolated in the network shall be

measured using a guarded resistance measuring technique as far as practical (see 3.1). Interpin resistance

shall be measured using the test instrument used for measuring the isolated resistors.