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

3.11.1 Solderability for leadless packages. The criteria for acceptable solderability during evaluation of the

terminations are:

The total surface area of the dipped part of the termination is at least 95 percent covered by a continuous

new solder coating.

That pinholes, voids, porosity, nonwetting, or dewetting are not concentrated in one area and do not exceed

5 percent of the total metallized termination area.

That there shall be no solder bridging between any termination area and any other termination area not

connected to it by design. In the event that the solder dipping causes bridging, the test shall not be

considered a failure provided that a local application of heat (e.g., gas, soldering iron, or redipping) results in

solder pull back and no wetting of the dielectric area as indicated by microscope of 10X.

The area of the surface to be tested as specified in 4.8.6c. shall include the total metallized area of both the

castellations and bottom terminal pads. In case of a dispute, the percentage of coverage with pinholes or voids shall

be determined by actual measurement of these areas, as compared to the total area.

3.11.2 Solderability for leaded packages. When networks are tested as specified in 4.8.6, they shall meet the

criteria as specified on figure 2.

The total surface area (except for the edge) of the dipped part of the termination is at least 95 percent

covered by a continuous new solder coating.

That pinholes, voids, porosity, nonwetting, or dewetting are not concentrated in one area and do not exceed

5 percent of the total wetting inspection area.

FIGURE 2. Solderability for gullwing packages.

3.12 Resistance to solvents. When networks are tested as specified in 4.8.7, there shall be no evidence of

mechanical damage and the marking shall remain legible.

3.13 Resistance-temperature characteristic. When networks are tested as specified in 4.8.8, the resistance-

temperature characteristic, at each of the temperatures specified in 4.8.8c referred to room ambient temperature,

shall not exceed the value specified:

Resistance temperature

Element tracking

Characteristic

characteristic

�300 ppm

�100 ppm

�50 ppm

C and V

�50 ppm

�5 ppm

�25 ppm