On Mon, 2007-10-15 at 10:17 +0000, Kai-Martin Knaak wrote: > On Mon, 15 Oct 2007 10:33:18 +0200, Gabriel Paubert wrote: > > > The problem > > is that the soldermask patterns pads are still rectangular and this > > means that the distance between the corners of the soldermask openings > > and the remaining copper is much smaller than with rectangular ground > > plane openings. > > Can you enlighten me: Why should the distance to soldermask be greater at > corners than at straight copper edges?
Registration mis-match between the copper and the soldermask printing. With square + square, the misalignment can be as much as +/- GAP With square + rounded, the misalignment is not allowed to be as big in both directions at the same time. (Eg.. if the registration is out both in the X and Y directions at once, it might mean mask covers the corner of the pad whilst the X and Y registrations are otherwise in tolerance. (It seems likely to me that the X and Y registrations are independent error terms, not some "distance" offset error in registration. -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) _______________________________________________ geda-dev mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-dev
