Lead Free Solder

[Robert A. Taylor]

Fred,

I want to answer your query via the server because I also want to get
feedback on my opinion to your solder question.

First of all, I would only use eutectic (60/40 approx.) solder because it
has the lowest melting temp of any combination of tin, lead, silver, etc.
As you know, I always use heat sinks on all components soldered into
equipment to prevent component degradation due to heat during the soldering
process.

Second, there are all kinds of 60/40 solder, some you would only use if you
were caught with a desperate need and it was the only solder you could find.
I classify the solder Heath supplied with the kits as near to that
specification.  Of all the solders I have used, my favorite is Kester "44"
0.032 dia. wire solder.  It is a resin core solder that is active enough to
clean well during the tinning process, yet inactive enough after soldering
to prevent corrosion if left on the joint.  I used alcohol or 1:1:1
trichlorethelene (no longer permitted to be sold I think) to clean the
joints after soldering to prevent flux damage in the long term.

Lastly, use a temperature controlled grounded soldering iron.  The
temperature and size of the tip were determined by the size of the component
to be soldered.  You want a tip large enough and/or hot enough to perform
the soldering job quickly before the heat could bring the heat sinks up to a
dangerous temperature and therefore pass the temperature on to the
component.  Heat sinks ranged from the light-weight alum clips sold for that
purpose to using them plus alligator clips to attach cotton swabs filled
with alcohol to the leads and/or the components.  This is especially needed
for solid state devices.  The grounded iron tip is very important with these
items to prevent leakage current from the iron from wiping out the device
either now or in the future due to electrostatic discharge.

Fred, I know you just asked about solder, but it is only one element in the
process.

I welcome the group input on this.

73's Bob, W2CNB

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