MILPRF55110G
APPENDIX A
A.3.7.3
A.3.7.3 Chemical requirements.
A.3.7.3.1
A.3.7.3.1 Cleanliness. When printed wiring boards are tested in accordance with A.4.8.3.1, the levels of
cleanliness shall be in accordance with the requirements of A.3.7.3.1.1 or A.3.7.3.1.2, as applicable.
A.3.7.3.1.1
A.3.7.3.1.1 Prior to the application of solder resist and qualification (see A.6.4). For qualification, and unless
otherwise specified, prior to the application of solder resist, the level of ionic contamination shall not exceed an
equivalent of 10.06 micrograms/square inch (1.56 micrograms/square centimeter) of sodium chloride. Alternative test
methods or test equipment specified in A.6.4 may be used in lieu of the method specified in A.4.8.3.1. When printed
wiring boards are tested using an alternative test method or test equipment specified in A.6.4, the final value shall be
less than the equivalents of sodium chloride specified for the printed wiring board surface area tested.
A.3.7.3.1.2
A.3.7.3.1.2 Completed printed wiring boards (when specified, see A.3.1.1 and A.6.2.2.g). The levels of cleanliness
for completed printed wiring boards shall be as specified.
A.3.7.3.2
A.3.7.3.2 Resistance to solvents (marking inks or paints). After marking is tested in accordance with A.4.8.3.2, any
specified markings which are missing in whole or in part, faded, smeared, or shifted (dislodged) to the extent that they
cannot be readily identified shall constitute failure.
A.3.7.4
A.3.7.4 Physical requirements.
A.3.7.4.1
A.3.7.4.1 Bow and twist. When tested as specified in A.4.8.4.1, the maximum allowable bow and twist of the
printed wiring board shall be within the limits specified (see A.3.1.1). If not specified, the limits for bow and twist shall
be 0.75 percent for designs that use surface mount components and 1.5 percent for all other designs.
A.3.7.4.2
A.3.7.4.2 Conductor edge outgrowth.
A.3.7.4.2.1
A.3.7.4.2.1 Conductors covered with solder. When the printed wiring board test specimen is examined as
specified in A.4.8.1, there shall be no outgrowth of the solder coating on the conductor edges.
A.3.7.4.2.2
A.3.7.4.2.2 Conductors covered with metals other than solder. After undergoing the test as specified in A.4.8.4.2,
the printed wiring board test specimen shall be examined as specified in A.4.8.1 and the maximum permissible
outgrowth on conductors shall be .001 inch (0.03 mm).
A.3.7.4.3
A.3.7.4.3 Plating adhesion. When tested as specified in A.4.8.4.3, there shall be no plating particles or conductor
patterns removed from the printed wiring board test specimen except for outgrowth or slivers.
A.3.7.4.4
A.3.7.4.4 Rework simulation. Rework simulation is not applicable for printed wiring board designs that do not use
any through-holes (unsupported or plated) for component attachment.
A.3.7.4.4.1
A.3.7.4.4.1 Type 1 with unsupported holes (bond strength). After undergoing the test specified in A.4.8.4.4.1, the
unsupported land shall withstand 5 pounds (2.27 Kg) pull or 500 PSI (3.4 MPa), whichever is less.
A.3.7.4.4.2
A.3.7.4.4.2 Types 2 and 3 with plated-through holes. After undergoing the test specified in A.4.8.4.4.2, the type 2
or 3 printed wiring board test specimens shall meet the following requirements:
External visual and dimensional inspection: When inspected as specified in A.4.8.1, there shall be no
a.
evidence of blistering, crazing, or delamination in excess of that allowed in A.3.5.
b.
Internal visual and dimensional inspection: After the printed wiring board test specimen is microsectioned
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