On Thu, 04 Oct 2007 00:00:26 +0000, Joerg wrote:
Eeyore wrote:
Joerg wrote:

I'll second John's and Rich's comments. Besides rounding you might want
to consider flaring the traces into the pin header vias. I think
layouters call that "drop". That way there could be less stress fractures.

Teardrop. It's astonishing how many good practices of old have been lost as a
result of CAD layout.

There was once a Marconi (Instruments) IIRC guide to pcb layout from the early
days of tape-up. It covered all these subtleties. I've seen excerpts but never
the actual publication.

I HAVE seen foil fractures where a thin trace enters a pad resulting from rough
handling, rework or whatever. Tear drops reduce such stresses hugely. It's basic
engineering.

PADS IIRC is the only package I've seen that has a teardrop function built in as
standard.

Eagle can do that as well AFAIK. But I never do layouts myself.

A lot of layout is common-sense and it gets violated a lot. Why on earth
everyone thinks right angle looks more cool that round traces I will
never understand. And then the stuff breaks.

Right angles are much more "modern" - like chrome-and-glass furniture as
opposed to art deco. ;-)

They're also easier to tape up. ;-)

Cheers!
Rich