> DJ - When you are etching your brass stencils they are almost all > resist and only tiny apatures. If you work out the cost of inkjet > ink and the amount of coverage you need - it may make a $200K laser > cutter seem like a prudent investment :D
More like $90k. I've checked. And you can put a drill/mill head on it and use it for other aspects of PCB making. But I don't have $90k :-P But I use a laser *printer* not a laser *cutter*. Printing a page of mostly-black isn't that expensive. > The photo paper is quite reasonable in terms of quality and I may > use it from time to time on single sided baords with 16/16 rules. I do 8/8 with TT but them I'm using the special paper that releases easily. > I am going to stick to photo for the DS 6/6 stuff though. The limiting factor (for me) for the TT is the quality of the edges. I haven't tried disableing REt though, it might be "dithering" the edges for me. > HCl/H2H2 (and the CuCl I use) do not give as sharp an edge as > FeCl3. Also I think for your brass masks that HCl may not be the > best solution. Check with someone smarter than me, but I think it > is bad with brass. The problem with brass is that it's *thick*. Consider an 8 mil opening in 5 mil brass - the opening is almost *square* vertically. The undercutting from the etchant distorts the shape of the hole. Hence my desire to etch from both sides; on 3 mil brass DS you're only etching through 1.5 mil, not 5 mil, that's 1/3 the distortion. Comapre to 1.3 mil for a 1oz copper PCB (or 0.7mil for 1/2oz that I use), and it's a big difference. _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user