Hi Mike,
> > I have discovered one neat trick with Eagle. It is trivial to get a
> > beautiful "ground plane" around all your traces. While still at
> > the "rats nest" stage of layout...just place a polygon (simply a
> > rectangle really) on the same layer as your traces. Make it the
> > size of your entire board. When you auto route...the autorouter
> > will automatically isolate all your traces from this "ground plane".
> > So, it is not really a "ground plane" as it is isolated from
> > everything else. But, with one little "blue wire" you can make it a
> > ground plane, if you want. I just do it because it will save on
> > etch time.
>
> Set its signal name is GND and Eagle will start routing to it.
You can also add the ground plane after you've finished routing. It's
important to use the polygon tool and NOT the rectangle tool.
After creating the polygon (on the bottom layer), rename it to GND (as
Mike mentioned) and then click on Change Isolation and change the
isolation to an appropriate value (you have to click on one of the
polygon edges).
When you click on the Ratsnest, it will redo the isolation. If you
already have ground traces, you can rip them up. I find that when I
open the board, the ground plae doesn't always show up properly.
Clicking on rats nest redraws it properly.
--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/