N_Cook wrote:

On 11/01/2014 16:46, Kaz Kylheku wrote:
On 2014-01-11, Doug White wrote:
0.5mm thick abrasive disc or cintride/"diamond" disc in a "Dremmel"

Thus throwing small conductive bits all over the board. No thanks...

Reconsider your objection. You can blow the filings away with compressed air,
and vacuum up.

The board is not powered up while you're doing this, right?

You could also mask the board off with a piece of paper (or whatever) that has
a cutout just for the IC, if you're paranoid.


Its not as though the bits of metal grow dendrite or tin-whisker
fashion. You'd have to be extremly unlucky to end up with a continous
patch of dozens of minute particles forming a continuous path.
Similar situation with solder paste, you cannot guarantee making all
those tiny balls molten and aggregate together as one


Really? You ever test new boards, right out of the reflow oven? A lot
of lead to lead shorts from balls of solder trapped under the IC's leads
if the reflow profile, paste solder and a dozen other things aren't
exactly right. I've removed hundreds of them from new boards. Metal dust
doesn't have to make good connections to cause problems. I had a batch
of new embedded computer boards come from the vendor with a problem. It
wasn't caught at incoming inspection, so we stuffed and reflowed them.
The were erratic as hell. I found the problem. The PCB house had
scratched the film along a +5V rail. This was arching to the parallel
ground plane, and right next to the input of an ADC. Know it alls claim
you can't have an arc at that voltage. All you need is enough potential
to jump the gap.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.