A guide to
soldering
BY JAMES L. ANTONAKOS
Finally, electronic components can simply be soldered
together. Soldering involves heating up the metal
leads of the components and then coating them with a
different molten metal. This makes for both good electrical
and mechanical connections, that ideally, will not come
apart when the leads of the components are moved
or vibrated.
A typical solder
is an alloy made
up of 60% lead
and 40% tin; it is
thus referred to as
60/40 solder. It
comes on a roll in
the form of a thin,
flexible wire that
is pushed into the
area being heated
to make it melt.
Figure 1 shows the
cross section of
three different
types of solder
wire, all of which
contain some
internal resin or flux
— a chemical used
to clean and wet
the metal surfaces.
There are many ways to connect
electronic components together to
form a working circuit. They can be
wire-wrapped or their leads can be
pushed into small metal springs
popular with 100-in-one electronic
kits available at RadioShack.
The components can also be placed
into small plastic cubes with metal
tabs on each side and inserted into
a two-dimensional grid to form a
circuit, another hobbyist fabrication
for fashioning your own electronic
projects.
FIGURE 1. Cross section of three
types of solder wire.
Let’s Begin
What do you need to begin soldering? First, you need
something to solder. This may be as simple as a few wires
that you want to tin or as complex as a radio or other
electronic kit that does something interesting. Next,
you need a soldering iron, some solder, and a small wet
sponge. Figure 2 shows all these items. A soldering iron is
essentially an electric heater. The tip of the soldering iron
gets very hot. Placing the tip onto the wire leads of two
components transfers heat to the leads. When the leads
get hot enough, they will melt the solder that is applied to
them. When the soldering iron is removed, the molten
solder will slowly cool and harden, making a strong, highly
conductive connection between the wire leads. As the
solder melts, it gives off smoke. Hold your head back
so the smoke does not get in your eyes — or lungs — as
you work.
The small wet sponge is used to clean the tip of the
soldering iron before it is used each time. The high heat
of the tip causes it to rapidly oxidize, which reduces
its ability to transfer heat. So, before you place the tip
Solder smoke - Try not to breath it!
64
February 2009
Cutting leads.
Wire tinning.