gEDA-user: n00b question: English - Metric connections

[Eric Brombaugh <ebrombaugh@xxxxxxxxxxxxx>]

Hi,

I've been coming up to speed on gEDA for the last few days and I've made 
pretty good headway with gschem & PCB. Nice tools - thanks to all who 
have made this possible.

I've got a fairly fundamental question: I'm using an 80-pin LQFP with 
0.5mm pitch. The rest of the components on my design are all 100mil and 
the board house I'm looking at using specifies 8mil line/space rules so 
I've chosen to go with my measurements in mils. Per the tutorials, I've 
started with 25mil grid and the layout went fairly painlessly until I 
tried the DRCs.

Connections from the 25-mil grid to the 0.5mm pitch on my LQFP is pretty 
ugly, so I usually dropped down to 5mil grid to make the last little 
trace to the LQFP pads. That still doesn't line up perfectly and I can 
see little bits of copper trace misaligned under the pads. Running DRCs 
is also pretty ugly - lots of spacing violations right at those pads.

Is there an accepted best-practice way to get around these 
english-metric misalignments? What about line spacing on the fan-in to 
the fine pitch pads? How to keep this from causing all sorts of violations?

Thanks,

Eric


_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user