8 Apr
2010
8 Apr
'10
9:49 a.m.
On 8 Apr 2010 at 9:00, Diane Bruce wrote:
That can cut your via. Safer to use a sewing machine
needle or pin.
Heat the solder until it is molten, clean with needle/pin as the
solder tends not to stick to the steel. In a pinch, the end of a
capacitor/resistor lead will do if you are careful.
If you can--often, the problematic pin is in a via between two large
lands and it's simply not possible to apply sufficient heat without
damaging things. I do have a sharpened stainless-steel pick that
will sometimes work (solder won't stick to stainless), but sometimes
you just have to drill. Using a needle or a component lead in this
case merely conducts more heat away from the area.
Another approach is to use Wood's metal (e.g. Chip-Quick) to lower
the melting point of the solder. I use that on SMT boards quite a
bit with excellent results, but it also works for through-hole
boards. Yes, it contains heavy metals which can be toxic, but it's in
metallic form (remember all of the shiny cad-plated hardware of a few
decades ago?).
--Chuck