On Wed, 2012-03-07 at 14:00 -0500, rickman wrote: > I'm not sure why you say this. Isn't the Gerber format a pretty good > way to specify the copper on a PCB? Isn't a bitmap what you are trying > to get in order to make the board? I guess you are saying it can be > hard to import to Gerbv?
Gerber probably does a half decent representation of the geometry. The code is pretty difficult to read and grok by hand though. When we specify things like drill files and routes, it seems more important to convey design intent though - which is hard. Do you realy need a 1.543mm drill and a 1.462mm drill, or would a finished hole size somewhere between 1.4mm <= hole <= 1.6mm be satisfactory for a reliable connection? Perhaps the fab can meet the tolerance spec on various different holes with different with fewer drills than the design has nominal drill values? It should (at some level), be up to the fab to choose the appropriate process and tooling to produce a board within the customer's requirements. This is where the interchange standards will let you down. How many people specify tolerances on their gerber data? The most I'd bet are controlled impedance design requirements, which is basically another "design intent" type metric for the manufacturer to follow. I could think of others, such as minimum clearance spacing for isolation standards, but it is unlikely the board house would have enough latitude in process controls to violate anything like that, unless they decide to get cute and use copper thieving patterns or something. (And in practice, I've not seen manufacturers do that kind of thing in the real world). Best wishes, -- Peter Clifton <peter.clif...@clifton-electronics.co.uk> Clifton Electronics ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Gerbv-devel mailing list Gerbv-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gerbv-devel
