MILPRF50884F
APPENDIX A
A.3.7.4.4 Adhesion, solder mask. When tested as specified in A.4.8.4.4, the maximum percentage of cured solder
mask lifted from the surface of the base material, conductors, and lands of the coated 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.3.7.4.5 Bow and twist (stiffener sections). When tested as specified in A.4.8.4.5, the maximum allowable bow
and twist for rigid or stiffener sections of the printed wiring board shall be, unless otherwise specified (see A.3.1.1),
0.75 percent for designs that use surface mount components and 1.5 percent for all other designs.
A.3.7.4.6 Flexibility endurance (installation use B only). When tested as specified in A.4.8.4.6, printed wiring board
test specimen shall be capable of withstanding the specified conditions of A.3.7.4.6.1 or A.3.7.4.6.2, as applicable,
without any evidence of damage, degradation or rejectable delamination. After the test, the requirements specified in
A.3.7.4.6.1 Qualification and periodic testing. Printed wiring board test specimen shall be capable of withstanding
the specified number of cycles without any evidence of damage, degradation, or rejectable delamination.
A.3.7.4.6.2 User specified (see A.3.1.1 and A.6.2.2). The number of flexing cycles, flexing rate, and points of
application of the flexing, travel of loop (if other than 1.0 inch (25.4 mm) minimum), and diameter of mandrel (when
applicable) shall be specified (see A.3.1.1). If no parameters are specified, use the qualification and lot acceptance
test default values of A.4.8.4.6.
A.3.7.4.7 Folding flexibility (installation use A only). When tested as specified in A.4.8.4.7, printed wiring board
test specimen shall be capable of withstanding the specified conditions of A.3.7.4.7.1 or A.3.7.4.7.2, as applicable,
without any evidence of damage, degradation, or rejectable delamination. After the test, the electrical requirements
A.3.7.4.7.1 Qualification and periodic testing. The number of fold cycles shall be 25 cycles in both directions. The
point of application shall be the center of the printed wiring board test specimen, orthogonal to the longest length.
The mandrel size for types 1 and 2 shall be 12 times the sum of the total ply thickness reduced to the nearest .125
inch (3.18 mm). The mandrel size for types 3, 4, and 5 shall be 24 times the sum of the total ply thickness reduced to
the nearest .125 inch (3.18 mm). The mandrel shall not be less than .125 inch (3.18 mm).
A.3.7.4.7.2 User specified (see A.3.1.1 and A.6.2.2). The folding flexibility test parameters shall be as specified
(see A.3.1.1). The minimum parameters specified on the master drawing shall be as follows:
a.
Direction of bend.
b.
Degree of bend.
c.
Number of fold cycles.
d.
Diameter of mandrel.
e.
Points of application.
32
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business