Markus Zingg <
homebrew-pcb@...> writes:
> I intend to use dryfilm laminate on both sides. The idea is to etch
> from both sides which I think might help keeping the undercuts at
> about half your rate. Just guessing though, and again, I definately
> will try this soon.
I thought of that. In my case, I couldn't align the toner sheets
accurately enough for that to work with the hole sizes I needed (0.5mm
pitch TQFP). I'm guessing with photoresist that's not a problem.
Working from one side also gives you a nice trapezoidal hole shape,
which helps release the paste. Big side down, of course ;-)