MILPRF50884F
APPENDIX A
A.3.7.3 Chemical requirements.
A.3.7.3.1 Ionic contamination (cleanliness). When printed wiring boards are tested in accordance with A.4.8.3.1,
the levels of ionic contamination shall be in accordance with the requirements of A.3.7.3.1.1 or A.3.7.3.1.2, as
applicable. The sodium chloride salt equivalent ionic contamination test equipment specified in A.6.4.2 can be used
in lieu of the method specified in A.4.8.3.1. When printed wiring boards are tested using the sodium chloride salt
equivalent ionic contamination test equipment specified in A.6.4.2, the final value shall be less than equivalents of
sodium chloride specified for the printed wiring board surface area tested.
A.3.7.3.1.1 Prior to the application of solder mask (see A.6.4). Unless otherwise specified (see A.3.1.1), the level
of ionic contamination shall not exceed 10.06 micrograms/square inch (1.56 micrograms/square centimeter) prior to
the application of solder mask.
A.3.7.3.1.2 Completed inner layer prior to lamination (when specified, see A.3.1.1 and A.6.2.2.g). The levels of
ionic contamination for completed inner layers prior to lamination shall be as specified (see A.3.1.1).
A.3.7.3.1.3 Completed printed wiring boards (when specified, see A.3.1.1 and A.6.2.2.g). The levels of ionic
contamination for completed printed wiring boards shall be as specified (see A.3.1.1).
A.3.7.3.2 Resistance to solvents (inks or paints). After ink or paint based markings or legends are tested in
accordance with A.4.8.3.2, any specified markings or legends which are missing in whole or in part, faded, smeared,
of shifted (dislodged) to the extent that they cannot be readily identified shall constitute failure.
A.3.7.4 Physical requirements.
A.3.7.4.1 Adhesion, coverlayer (including coverfilm and cover coat). When tested as specified in A.4.8.4.1, the
maximum percentage of cured coverlayer lifted from the conductors, lands, or surface of the printed wiring board test
specimen shall be in accordance with the following:
a.
Bare copper or base material: Maximum percentage of lifting 0 percent.
b.
Gold or nickel plating: Maximum percentage of lifting 5 percent.
c.
Melting metals (tin-lead plating, solder coating, indium, bismuth, and others): Maximum percentage of lifting
10 percent.
A.3.7.4.2 Adhesion, legend and marking. After legends or marking are tested in accordance with A.4.8.4.2, any
specified legend or markings which are missing in whole or in part, faded, shifted (dislodged), or smeared to the
extent that it is no longer legible shall constitute failure. A slight change in the color of ink or paint markings after the
test shall be acceptable.
A.3.7.4.3 Adhesion, plating. 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.
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