> Nevermind -- I just checked the gerbers I sent to the fab in gerbv, > and the overlapping silk has clearly been deleted. And yet, there it > is right there in green and white on the boards that came back. How > could this happen? Is it that pcb writes the complete silk layer to > the gerber along with commands to delete the overlapping portion? > (I'm pretty ignorant about the gerber format, so forgive me if this is > a silly question...) > > If this is so, then it would seem that pcbexpress.com ignores these > "delete" commands. Am I justified in telling them to re-do the boards > at their expense? They might complain, since I didn't use the "free" > gerber viewer they recommend to check my files, ViewMate from > www.pentalogix.com. Of course, that gerber viewer runs only on > Windows on is only free as in free beer.
FWIW, I have also had problems with boards at ExpressPCB. In my case they did not put thermals or reliefs from drilled holes onto a board with a GND plane on the back layer. Therefore, all my through holes were shorted to GND. I looked at my Gerbers with GCPrevue (a very popular freeware Windoze viewer) as well as with gerbv. Both programs showed that the reliefs were there. I took some screenshots of the Gerbers (in GCPrevue), as well as some digital photos of my board. I then wrote a quick MS Word doc describing the problem & sent it to ExpressPCB. They did fix the problem, and sent me respun boards free of charge, a move I respect. You can probably do the same with your boards. I think it's best to send some documentation so they can see the problem. Nonetheless, I wouldn't recommend sending them boards to fab in the future. Their software doesn't seem to work well with the Gerber exported by PCB. I wonder if their mfg software has problems with other CAD tools also? The best vendor I have used for PCB designs is Advanced Circuits (www.4pcb.com); I think other people on this list will second this recommendation. Stuart
