I. SOLDERING TECHNIQUES
Care must be exercised, and good soldering
techniques used, in the repairing of printed
circuit boards. Excessive heat or poor
workmanship can easily damage foil and
components on a printed circuit board.
It is recommended that soldering irons exceeding
60 watts maximum NOT be used. DO NOT use a
soldering gun.
De-soldering components from printed circuit
boards is not difficult to master if some simple
rules are followed:
a. Soldering Iron
The soldering iron tip should be of the
tapered type, 1 /8" or less. For maximum
heat transfer, the soldering iron must be
kept clean and tinned.
b. S
o
l
de
r
Wick
#3
There are two different means of removing
solder from a component pad on a printed
circuit board. One, using a solder sipper,
and two, using solder wick.
A solder sipper is a suction type device that
draws the solder from the pad once melted.
Solder wick is a copper braided material that
absorbs the melted solder. Unless a person
is proficient at using a solder sipper, we
recommend using a solder wick.
#3 solder wick is approximately 1 /8" wide
and is available in 5 foot lengths from any
electronic supply store.
c. De-soldering Procedure
1. Apply the solder wick to the pad to be
desoldered, see figure 6-8.
16
)
Figure 6-8
2. Place the soldering iron tip on the
soldering wick directly over the pad to be
desoldered. Press down, firmly but
carefully.
The heat from the soldering iron will
transfer through the solder wick to the
pad. The melted solder from the pad will
be drawn into the solder wick. Continue
this process until the solder is removed
from around the component lead.
3. With a pair of pliers, grasp the lead of
the component to be desoldered where
it extends through the printed circuit
board. Gently move it from side to side
to break any solder connection. Note: if
the lead doesn't move freely in the hole,
it may be necessary to repeat step #2.
