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Ralph Mowery

In article ,
says...

In article ,
Ralph Mowery wrote:

I have not bought any yet and have been practicing witht he SMD on old
computer boards. That stuff seems a pain to work with compaired to the
'regular' tin/lead that I have been using for the last 50 years.

Ralph-

I sympathize!

The problem with using tin-lead solder with SMD, is that lead
"amalgamates" with the silver contacts of surface mount devices,
resulting in a non-conductive layer between the device and the circuit.

While tin-lead-copper solder may help, it would be better to use
lead-free. It may work better if you use a temperature-controlled iron,
capable of higher temperatures than your old iron.

Fred

Ok Fred, thanks for explaing the 'amalgamates' part. Looks like I will
be getting some of the lead free solder. I know the old gold plated RF
power transistors gave a lot of problems due to the gold plating of the
leads, so guess the lead free boards are doing something similar.

I do have a couple of temperature controlled irons. Also bought one of
the hot air gun and soldering pencil stations. Just an inexpensive one
for about $ 65 off Ebay. Seems to work well on the regular leaded SMD
boards. I have been running the irons up much higher to match the lead
free boards.

I have been looking at a lot of the Youtube vids about the SMD soldering
and they make it look easy. The boards with the tin/lead solder I have
been practicing on usually turn out very well, not so much for the lead
free stuff. I do have one small tube of solder that has some silver in
it but not sure what else. I need to look it up on the internet and see
what it is actually made of. It is some from some samples we got when I
was working and no one ever used. The tube does not state the makeup,
just thatit has some silver in it.