On Thu, 14 Jul 2005 09:55:36 +0200, Phil <
phil1960us@...> wrote:
>
> However, I wouldn't focus on using fat traces for avoiding copper
> removal. I think that would be the hard way to do it. I much prefer
> to create a ground polygon that encompasses the entire board and then
> let the layout software figure out the actual shape. In eagle, I put
> a ground poly on both the top and bottom with isolate set to 24 mil.
> Then I route the board. The only places eagle will take copper is for
> isolation and "orphaned" copper areas (not connected to ground).
> Look at http://www.geocities.com/pcbs4less/boardtop.gif for an example
> of this. Red and green are copper areas/traces. As you can see, this
> design keeps much more copper than one using just fat traces. It
> seems much cleaner and makes for a quieter board, noise-wise, because
> of the extensive ground areas.
> Besides, thin traces just look more professional to me
> Phil
I agree, reasonably thin looks better.
I also make groud planes, but i always wondered about islands. You say you
don't leave the copper there, which i only partially understand (though i
do the same, i just don't know exactly why).
How bad are they? I mean i can imagine they could potentially provide more
capacitive coupling between signals which is unwanted, but is that really
an issue?
Have you any information about that?
Sometimes those gaps don't look right, and i'm tempted to leave them.
I usually use 10mil for signal traces and 20 mil for power, but i've also
made boards with 1mm traces for customers if they want, where 10mil would
have been plenty, and it doesn't look bad if the components are right for
it (only throughhole, not many ICs, ..) Esp. if all traces are that wide
and none are thinner it looks ok.
ST