given the 0.01 mill base unit I would like to have a grid of 4 mills. This would allow 4 mill traces and 4 mills of clearance between traces.
The grid error for 50 mill pitch components would be no greater then 2 mills the grid error for 1mm devices would be under 48 microns (~1.8 mills) for the 50 mill pitch parts there will be a margin of 8.5 mills. (25mills pad / 2) - worst case error - (trace width / 2) 12.5 - 2 - 2 = 8.5 mills for the 1 mm pitch the margin .25 mm - .048 mm - .0508 mm = 0.1512 mm ~6 mills Steve Meier On Tue, 2008-06-10 at 18:39 -0400, DJ Delorie wrote: > > What unit should we define for PCB default units? > > For compatibility, the default (no units specified) should remain 0.01 > mil. > > > _______________________________________________ > geda-user mailing list > [email protected] > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
