--- Louis Schulman <louiss(a)gate.net> wrote:
My questions is this: Is the copper itself sufficient
to carry the
currents, or is the tinning required to reduce
resistance?
I'm not sure it has anything to do with resistance.
Or, putting it another way, is the tinning required,
or is
it just to assist in attaching components?
Tinning _does_ help with attaching components.
Or, putting it one last way, do I need to re-tin the
bare spots?
I would. Carefully.
I think the biggest benefit gained from tinning spots that _don't_
have components attaching to them is that bare copper traces could
oxidize all the way through, especially if they are exposed to a
corrosive agent (from ammonia to human sweat). I think tin oxides
are more protective of the underlying metal, much like aluminum
oxides.
I am not a chemist or metallurgist, but I _think_ it works like that.
-ethan
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