Homebrew PCBs

On Tue, 08 Nov 2005 00:12:41 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

> Stefan,
> By chance do you happen to know what process the board MFGs use to
> remove the excess copper? (as in etching boards the way we do to leave
> only the traces)
> I am guessing it is a chemical etching of some sort, but have no idea
> beyond a guess.
> Chris


usually chemical etching. as far as i know mostly sulphuric etchants and  
some CuCl, conveyor spraying any maybe bubble tanks in smaller operations  
i think.

Most seem to use laminated film resists (as those are tenting THP), or  
"inverted" resist and tin plating with sulphuric etchants.

That's what i gathered seems common, not 100% sure. Never seen a  
industrial etching shop inside, actually. There are sure ppl here that  
have seen some.

ST