TM 11-5895-1090-34/TO 31 R2-2TSC-152
WARNING
NOTE
Adequate ventilation should be provided
If one lead of the component is to be
while using TRICHLOROTRIFLUORO-
connected to a ground plane, connect
ETHANE. Prolonged breathing of vapor
that first. If no connection is to be made
should be avoided. The solvent should
to the plane, proceed to (4) below.
not be used near heat or open flame;
the products of decomposition are toxic
(3) Preheat the through hole connected to the
and irritating. Since TRICHLOROTRI-
ground plane. When the solder begins to melt, insert
FLUOROETIHANE dissolves natural
oils, prolonged contact with skin should
(4) Gently maneuver the component to insert
be avoided.
When necessary, use
leads into the proper through holes. Continue with a
gloves which the solvent cannot
gentle rocking movement until the component is
penetrate.
If the solvent is taken
inserted to the proper depth, or until the body of the
internally, consult a physician im-
component makes contact with the surface of the circuit
mediately.
board. Heat through holes as necessary to install
component.
NOTE
(1) Use a small paint brush or the tip of a pipe
cleaner dipped in trichlorotrifluoroethane; and carefully
Do not crimp or bend leads to hold the
clean both sides of the surface area, the through holes,
and pads.
The protruding portion of the lead
(2) Observe polarity markings, and properly
should remain straight to prevent
orient the component. Shape the leads of the new
damage to the circuit board if
component so that the leads fit freely into the correct
subsequent replacement is required.
through holes.
CAUTION
(5) Use diagonal cutting pliers to cut leads so
When installing diodes, attach a
that the protruding lengths match those of other
heatsink to the lead, near the body of
components, approximately 1.5 mm (0.063 in.).
(6) Use flux and solder sparingly. Solder each
apply heat at a through hole for longer
lead at the side opposite the component. Be sure that
than 8 seconds. Figure 4-13.
the component does not shift position during the
soldering procedure.
(7) Carefully inspect all new solder points for
are removed. A round toothpick may be used to help
evidence of poor connections, cold solder, or short
remove heavy rosin deposits. Solder points should
circuit. Solder should completely fill the through hole
appear clean, smooth, and bright.
(9) Use a small paint brush dipped in urethane
(8) Use a small paint brush or the tip of a pipe
coating (M4605-8 Type UR or equivalent) and cover all
cleaner dipped in solvent and thoroughly clean all new
new solder points on both sides of board.
soldered points.
Be sure that all flux and rosin
4-18