On Sat, 2010-09-11 at 21:44 +0200, kai-martin knaak wrote: > Peter Clifton wrote: > > > Just how useful is anti-copper? > > I'd use it for text in copper (less space demanding than regular, > positve text). Anti-text in mask would be neat, too. It is even less > space hungry. Letters look fine if the exposed copper surface is HAL or > even better, gold plated. > > Real anti-objects in mask would be useful with regular text in copper, > too. Currently, I expose the copper with a zero width line converted to > footprint and equipped with massive clearance. In addition, I tell the > fab to just ignore the zero width lines. > > Yes, this is a hassle. But I really like to have the purpose of the > board stand out in large and friendly letters, even on prototypes > without silk print.
I've done it before too. (I first encountered the idea on a board one of my students, made using Protel I think). > > Is it mitigated by allowing holes in polygons? > > Can a footprint contain such a hole? No, the hole is a part of the definition of the polygon, not an object in its own right. I think you just gave me the most solid reason I've heard yet for explicit anti-objects / anti-layers. We probably need to define some rules as to which objects take precedence over others. One way might just for a "keepout" object to auto-clear polygons, and perhaps just flag a DRC warning for other objects the user places in the area. We wouldn't want a component's keep-out erasing tracks leading to the component, or the component's pads etc.. At first sight, I can't quite envisage how those will be differentiated from a keep-out violation. (Can someone who uses / has used keepouts on another package describe for me how they work, or how you use them?) Best wishes, -- 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!) Tel: +44 (0)1223 748328 - (Shared lab phone, ask for me) _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
