Tinning on old PCBs

From: Louis Schulman <louiss_at_gate.net>
Date: Thu Dec 20 19:06:44 2001

On Thu, 20 Dec 2001 19:39:31 +0000 (GMT), Tony Duell wrote:

#> before tinning, so the tinning lost its grip.
#
#
#Do you mean the 'tinning' -- as in the solder layer? Or the (normally
#green) solder mask? If it's the latter, then don't worry about it.

I mean the tin/lead solder coating. There is no green mask on this board, it is bare.
#
#>
#> My questions is this: Is the copper itself sufficient to carry the currents, or is the tinning required to
reduce
#
#Oh, I think the copper will easily carry the current...
#
#What worries me is that if this tinning is flaking off, are the soldered
#joints between components and the tracks still good. Or are they going
#open-circuit. If I had a board like this, I'd want to resolder everything...

Well, I have this concern as well. My theory, since I don't want to resolder everything, is that when the
components were soldered, this reflowed the tinning on the track, making a better bond. The board works,
so there are evidently no open circuits. The copper where the tinning peeled off has a tarnished color.
#
#> Or, putting it one last way, do I need to re-tin the bare spots?
#
#And yes, I'd re-tin any tracks with missing tinning.
#
Louis
Received on Thu Dec 20 2001 - 19:06:44 GMT