DRC errors for precisely minimum distance

[Joakim Nilsson]

I was designing a break out board for a chip, so I needed to use really thin wires. Anyways, I had the minimum wire width (and spacing) set to 5.91 mil while routing my board and everything seemed to work well and I didn't get any DRC errors. Anyways, when I restarted pcb and made a new DRC, I started getting errors claiming that the minimum widths and spacings were violated in several places even though the distances were given in the error equal to the minimum width. An example:

Line width is to thin (5.91 mil)
Process specifications dictate a minimum feature-width that can readily be produced
Required: 5.91 mil

Note here that it states 5.91 mil in both places. The DRC errors went away if I lowered the minimum requirements to 5.90 mil.

[DJ Delorie (djdelorie)]

Could you upload a sample board that fails? There might be some rounding issues in the mil-nm conversion...

[Joakim Nilsson (nijoakim)]

Yes, of course. Unfortunately, I cannot reproduce the "Copper areas to close" error, so I'll forward both my entire project which is in the "gaf" folder and also a minimum layout ("pcb-bug") which produces the "Minimumm width" error.

[Joakim Nilsson (nijoakim)]

Sorry for spamming, but I forgot to add that the footprints used in project ("gaf" folder) is contained in "gaf/pcb-elements/".

[Joakim Nilsson (nijoakim)]

Also, as a suggestion, I think it would be useful if the actual spacing is printed out even in the case for the "Copper areas to close" errors. (This is done for the "Minimum feature width" errors.)

[Chad Parker (parker-charles)]

This issue is specifically about the size of objects. This has been corrected at some point. There are still issues associated with clearances that are equal, but those are covered under different reports.