[sdiy] Dual ground planes

[David G. Dixon]

All this talk about ground planes has got me to wondering...

I lay out one-sided boards in Excel (it's antediluvian, but it suits my
cockeyed sensibilities) with lots of jumpers.  I always fill in the empty
spaces with "ground" as I can, or just leave islands of unconnected copper.
My boards are usually pretty densely populated, and the end result almost
looks like a machined board.

What I'm wondering is this: does this make any difference whatsoever, or
would I be just as well off simply having ground traces, with no islands of
unetched copper (grounded or not)?


> Are you talking 2-layer here? I'll assume you are. Also I'll assume you're
> not
> going for EMC compliance here. Mostly dual ground planes give you better
> ground
> paths (obviously). This becomes an issue if there are lots of traces
> cutting
> across the board. Also if you have mixed signal (analog&digital) having
> planes
> on both sides can make splitting the ground planes easier.
> 
> Given all of that, ground planes are not critical to the basic design. But
> as
> performance requirements go up the use of ground planes become necessary.
> As an
> example, I just added a quantizer to my Muse thingie. It is all hand-wired
> with
> no ground planes. The signals are okay, but I can see little wiggles when
> I poke
> around the circuit. Most likely from inferior grounds. The circuit works,
> but
> could be better.