MIL-PRF-27208F
3.30 Solder.
3.30.1 Solder, flux, and soldering. Materials and processes for soft soldering shall be as specified in 3.30.1.1 to
3.30.1.3 inclusive.
3.30.1.1 Soft solder. Soft solder, when used for electrical connections, shall conform to composition Type A of
3.30.1.2 Flux and cleaning agents. Flux for soldering electrical connections shall be resin or resin and alcohol. No
acid or acid salts shall be permitted for pretinning of electrical connections, for tinning of electrical connections, or for
tinning or soldering of mechanical joints not used to complete electrical circuits. In no case shall acid or acid salts be
used where they come into contact with insulation material. Where acid or acid salts are used, as permitted herein,
they shall be completely neutralized and removed immediately after use.
3.30.1.3 Process. Soldering connections shall be neat. There shall be no sharp points, rough spots, or surfaces
resulting from insufficient heating. The solder shall feather out to a thin edge, indicating proper flowing and wetting
action, and shall not be crystallized, overheated, or underheated. The minimum necessary amount of flux shall be
used for electrical connections. Wherever practical, excess resin shall be removed with a wire brush and dry cloth.
Any resulting loose flakes of resin shall be removed. Insulation resistance material that has been subjected to
heating during the soldering operation shall be undamaged and parts fastened thereto shall not have loosened.
3.31 Welding and brazing. Where welding and brazing is employed, the electrical connections shall be
mechanically secure and electrically continuous after welding or brazing. Where brazing is employed, only
substantially noncorrosive fluxes shall be used, unless it can be shown that corrosive elements have been
satisfactorily removed after brazing.
3.32 Marking. Resistors shall be permanently marked with the PIN and manufacturer's name and or trademark.
The circuit diagram shall be marked on the resistor as specified in 3.4.3.1. The location of the manufacturer's code
symbol shall be at the discretion of the manufacturer. Marking shall remain legible at the end of all tests. There shall
be no space between symbols that comprise the PIN. If lack of space requires it, the PIN may be set in two lines. In
this event, the PIN shall be divided between the characteristic and terminal symbols, as shown in the following
example:
RT10C2
P102
3.33 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally
preferable materials should be used to the maximum extent possible provided that the material meets or exceeds the
operational and maintenance requirements, and promotes economically advantageous life cycle costs.
3.34 Workmanship. Resistors shall be processed in such a manner as to be uniform in quality and shall be free
from other defects that will affect life, serviceability, or appearance.
4. VERIFICATION
4.1 Classification of inspections. The inspection requirements specified herein are classified as follows:
a.
Qualification inspection (see 4.4).
b.
Conformance inspection (see 4.6).
4.2 Test equipment and inspection facilities. The manufacturer shall establish and maintain a calibration system in
accordance with NCSL Z540-1, ISO 10012-1, or equivalent system as approved by the qualifying activity.
10
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business