DZ HT-7, Инструкция по сборке, Страница: 10 / 44

Page 10
SOLDERING INSTRUCTIONS
Poor soldering accounts for almost 90% of all kit building problems.
The photographs below show examples of the most common types of bad
solder connections and a good one. If you locate any of these bad sol ‐
der connections in your kit, correct them as described. Study this
section carefully before you start building your kit.
Use a good quality, variable tem ‐
perature soldering iron with a
conical, narrow tip, and set the
temperature to 750 degrees F. Use
thin, non ‐ corrosive, rosin core
solder to assemble your kit. Keep
the sponge damp and wipe the tip
on the sponge after each solder
step.
Solder blob. In this example,
solder flowed onto a lead, but
the heat was not maintained long
enough for it to flow onto the
circuit board pad. Solution: re ‐
heat the connection, touching the
iron to both the component lead
and the pad at the same time.
Solder bridge . Solder that
stretches from one trace or pad
to another creates a short cir ‐
cuit. Solution: Hold the board
upside down and reheat the area.
The excess solder will flow down
the soldering iron. Another so ‐
lution is to use a “solder
sucker” or solder wick to remove
excess solder. Solder suckers
work well one or two times on a
given connection. If used too
much, they can pull pads and
traces off of PC boards.
A good solder connection looks
like this. Solder flows evenly
onto both the part and the PC
board or chassis component. It is
shiny and even, not lumpy and
dull. The component lies flat on
the board. Leads that are prop ‐
erly soldered can not be moved in
the hole. You can find bad solder
connections by measuring the re ‐
sistance, using an ohmmeter, be ‐
tween the component’s lead (where
it attaches to the body of the
part) and the other end of the
trace. If it reads infinity (or
very high) the connection is
open.