Steve Meier wrote: > Gene, > > My understanding is that the minimum solder mask is dimension is 5 mills > (check with your vendor). So if you have a solder mask cover of 5.5 > mills between pad openings then a trace of 4.5 mills or smaller should > not be a problem. I have used traces as small as 3 mills. I believe for > the copper layers this suggests you should use 0.5 oz copper thickness. > > Steve Meier > >
I checked a couple of online fab outfits, and found at least one that will do 6 mil trace with 6 mil space. I think 3 mil is going to be a little out of the ordinary. For now, in order to avoid any additional cost, maybe 6/6 is a good size to use for those dense areas. But then again, that means minimum space between pins of 18 mils. That won't fit very well in the .8mm pitch part I described and looks pretty much impossible on 0.50mm pitch part. Maybe the better solution is to run the bus on one side of the card, and drop vias from the other side. It's just going to make a lot of swiss cheese, I think, on the card. I'm open to suggestions :) gene _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user