A warning to anyone making PCBs - and maybe to get some devs thinking, I'm not sure if there's a better way to do this:
For those who didn't know, "subtract soldermask from silkscreen", for Gerber, is implemented by plotting the silkscreen, then switching plot modes to 'clear' with the %LPC*% command and plotting the mask over the top. This is like "drawing" the mask with an eraser, clearing out the silk layer. I sent a board off yesterday, to Elecrow, which had an empty back silkscreen. I sent the file anyway, to make sure they were aware I indeed wanted it empty and didn't just forget the file. Got an email a few minutes ago telling me my silk and mask layers were the same and asking me to check them. Checked the files I sent them and confirmed this wasn't the case, my files were fine - though I was led on a wild goose chase by the fact that the silk layer contained the whole mask layer in negative. What I believe happened is that their software saw a layer with all negative drawing, and automatically inverted it. Probably meant to detect gerbers generated by old-fashioned EDA packages or packages with old-fashioned settings that output power plane layers in negative. Something to watch out for - if your silk layer is empty, either don't send it, or don't use "subtract soldermask from silkscreen". I wonder if we can do anything about this from the software side, like not generating the mask negative if the silk is empty. -- Chris _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp
