Re: gEDA-user: PCB: how to clear soldermask from entire footprint

[Dan McMahill <dan@mcmahill.net>]

On Sat, Nov 06, 2004 at 05:42:12PM -0500, DJ Delorie wrote:
> 
> > > Areas the autorouter shouldn't put traces through.

I'd expand that to autorouter or human router.

> > 
> > What's the reason for such areas?
> 
> Mounting brackets, component contact, EMI, isolation, etc.
> 
> For example, on my furnace controller I didn't want the logic lines
> getting too close to the power lines, so I manually drew big fat
> tracks between them before routing.  If I had keep outs, I could have
> drawn those tracks on the keep outs and not had to go back and delete
> them later.

Another example is something like a microstrip filter or resonator.
For proper operation, you may require that other copper stay some
distance away.  As an extreme example, consider some microstrip filter
with a grounded stub.  You'd hate it if an autorouter or sleepy 
human decided any piece of that metal was an OK place to ground
something to.

-Dan

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