Re: gEDA-user: PCB square pin suggestion

[DJ Delorie <dj@xxxxxxxxxxx>]

> Why?

It may keep a polygon island from getting disconnected or necking down
below DRC parameters.  It may allow for an extra trace between pins.
If the pin is intersected by a 45 degree line, it prevents notches
from being cut out of the clearance:

http://www.delorie.com/pcb/notches.html

It does get ugly when you have a row of square SMD pads, though.  You
end up with lots of little triangles cutting into an otherwise
straight clearance edge.  I think, if we decided to use rounded-corner
clearances, we'd need to be intelligent about rows of pads with
overlapping clearances, and join them into a single rounded-corner
clearance that covered them all.  That might speed up display and
reduce gerber file sizes, too, even if we implemented it for
square-corner clearances.