[sdiy] Solder mask

[jhaible]

> > I scrape with the egde of a sharp X-Acto knife.  Solder mask comes
> > off in a scrape or two.  Maybe practice on a trash board if you have
> > never done it, for practice...
>
> I second this... altghout I call the knife something completely different.
> It is usually not very hard to scrape of the mask layer,


I'm using a screwdriver.

Now if you think getting to a copper trace thru the solder mask is
difficult, you'd be surprised what else is possible on pcbs.
At least *I* was surprised when I saw it.

While debugging a circuit on a multilayer board, I saw a guy going
thru several layers with a dremel and making contact to one of the
inner copper layers. (That was EMC debugging, so tracing the
signal to a point where it would eventually come out to a surface
layer was no good.)
These layers are 35um of thickness - a little too deep and he would
have gone thru it ...

How would you call this - "Archeological Electronics" ?

JH.