"warrenbrayshaw" <
warrenbrayshaw@...> writes:
> Depending on the copper thickness and your etchant chemistry you can
> compensate for the undercutting of the etch resist.
Actually, I already thought of this. When I wrote the postscript
output plugin for PCB, I added a "bloat" option that lets you expand
all the toner by some amount (units of 1/100 thou, negative allowed)
to compensate for variations in the process, both printer and etch.
I put a test board here:
http://www.delorie.com/pcb/ - scroll down to
"Goodies". It has various line/space rules from 1/1 to 12/12, with
bloats in 0.25 thou increments from -1.5 thou to +1.5 thou.
Both gerber and pdf are available for download.