[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
RE: gEDA-user: DRC problem at close pads
Prepatch, you could have just ignored the PCB DRC bug in a footprint you
knew to be accurate.
> -----Original Message-----
> From: geda-user-bounces@xxxxxxxxxxxxxx [mailto:geda-user-
> bounces@xxxxxxxxxxxxxx] On Behalf Of David Kuehling
> Sent: Tuesday, February 27, 2007 1:10 AM
> To: gEDA user mailing list
> Subject: Re: gEDA-user: DRC problem at close pads
>
> >>>>> "Dan" == Dan McMahill <dan@xxxxxxxxxxxx> writes:
>
> > David Kuehling wrote:
> >>>>>>> "DJ" == DJ Delorie <dj@xxxxxxxxxxx> writes:
> >>
> >>>> http://user.cs.tu-berlin.de/~dvdkhlng/clearance-problem.png
> >>
> >>> Could you post (or send me privately) the .pcb file?
> >> Here is a simplified file that only contains the problematic
> >> footprint. Quite possibly this is just a problem with the
footprint?
> >> After all this was hand-coded in M4...
>
> > I'd be more likely to suspect the footprint if "after all it was
hand
> > drawn instead of generated programattically"...
>
> > Ok, here's the deal. It is a bug in pcb. Square (or rectangular)
> > pads are checked by growing one of them in X and Y on all 4 sides by
> > the minimum space. This of course means that the corners grew by
> > sqrt(2) more and thats why you got a failures. I'll try to cook up
a
> > patch tonight.
>
> Yes, I now remember having seen some illustration in the PCB user
guide
> (section 7), illustrating how lines (pads) with rectangular ends are
> drawn by a rectangular aperture (on page 57).
>
> The clearance is drawn as a rectangle, so one could take the current
> behaviour as being right. Else somebody would have to fix the
> documentation :)
>
> I already reworked my footprint, moving the pads a little outwards.
> Hopefully this will work in production (but since there isn't an
> oficially recommended pcb layout for the chip in question the
footprint
> is a rough guess anyway).
>
> Thanks also for your patch. But since my layout already changed,
there
> might not be much testing that I can do. I'm going to upgrade PCB
> anyway before exporting the final gerber files (I heard of some
problems
> which aren't fixed yet in pcb-2006082) and will then test the patch.
>
> regards,
>
> David
> --
> GnuPG public key: http://user.cs.tu-berlin.de/~dvdkhlng/dk.gpg
> Fingerprint: B17A DC95 D293 657B 4205 D016 7DEF 5323 C174 7D40
>
>
>
> _______________________________________________
> geda-user mailing list
> geda-user@xxxxxxxxxxxxxx
> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user