Dual Layer Ground Planes on PCB's.

[raulduke]

Hey Guys, doing a layout and I have a quick question...

Are there any disadvantages in using two ground planes on a 2 layer PCB (ie. top and bottom layers)?

Dual ground planes are something I have not really seen with a lot of guitar PCB's, so I was wondering if there are reasons why...

Cheers!

[croquet hoop]

I am not sure there are any disadvantages. I think Pickdropper often uses two ground planes, so from this fact alone I'd say it's not a bad design choice

[rullywowr]

I am also a proponent for dual ground planes.  If not, then just one on the bottom is fine.

I discourage using a positive side rail on one side and GND on the other as this creates a type of mild capacitor plus makes it easier to have an unintended short between the layers.

Having more copper on the board means less etching required, plus a thicker/more sturdy PCB overall.

[raulduke]

Thanks for the words of wisdom guys.

I stopped doing V+ as a plane a while ago as I figured it can't be a good idea!

Think I'm gonna just go ahead and do dual ground planes from now on.

As you say; less copper to etch away too.

[pickdropper]

Dual grounds is indeed preferable whenever possible on 2-layer boards.  It can also help to add via stitching to tie them together.

Top and bottom ground planes aren't quite as important on a 4-layer board (assuming one of the inner layers is a ground plane) but they can help to some degree.

[Vallhagen]

I actually go to the opposite direction; i tend to skip ground pours today. I dont see any real advantages in our applications as everything happens in low (audio) frequencies. Besides (and not to forget); it is convenient when designing, and (as said in thread) it saves on the etch process.

It should be said though, i am open to any argument that sais im wrong (it has happened before;) ).

Cheerio

[pickdropper]

The argument for doing dual ground pours is that it usually lowers the noise floor.

The argument against it is that can, on occasion,  make it worse if there is a noisy component or circuit section polluting the ground plane.

But it's usually beneficial to pour ground. (At least for these types of circuits ).