I have seen that in some cases the ground plane is only on the lower (solder) side of the PCB, and in other cases in is on both sides. What is more correct? I really don’t know much about this but it seems to me that having a ground plane on both sides looks like a giant capacitor!
There is no voltage across it so it can’t act as a capacitor. It actually screens the board better, and provides shorter return paths for current. They aren’t ground planes, anyway; they are copper pours. Ground planes are (ideally) uninterrupted copper layers.
Leon
Nearly all of my 2 layer boards have a GND copper pour on the bottom and a VCC copper pour on the top. The copper is there so you might a well use it. It make routing more complex boards alot easier too.
gussy:
Nearly all of my 2 layer boards have a GND copper pour on the bottom and a VCC copper pour on the top. The copper is there so you might a well use it. It make routing more complex boards alot easier too.
But, does that not reduce noise immunity? I thought that a star routing (for ground at last) is supposed to be better and/or solve noise issues.
Not for digital circuitry.
Leon