Gridded Ground Plane & 2 Layer PCBs

Hey all,

I have been doing some research on dual sided PCBs for a project I am currently working on and I came across the concept of ground planes. I believe I understand the general gist of how they operate and their purpose, but what I do not understand is how they are re implemented and then utilized. A bunch of resources on the internet explain what they are, but I have not been able to locate even a simple tutorial for how to utilize one on a PCB, but rather other questions about designing them in EAGLE (I am using AutoCAD). I do not think I need any help designing the plane aside from general rules about their placement or similar tips.

For aesthetic reasons, I would really like to do one of those grid style ones, similar to what is on the top of the Duemilanove. What I believe I am supposed to do is have a piece of exposed copper on the top side of a ground connection soldered to the component ground pins, but again I am not sure.

It's best to use a solid copper fill. Those large areas of copper help a lot in spreading out and dissipating heat. So I suppose that's rule number one: use them to dissipate heat. If you need a decorative pattern it would be better to do that in the printed/text layer.

I suppose the second rule is just convenience; it's easier to use a ground plane (or a positive voltage plane) than pull traces all over the board.

My understanding is that grid or patterned fills are used to reduce warping of the board when it heats and cools. That might be important on a computer motherboard or such but not basic microcontroller projects.

In brief for Eagle:

Use the polygon tool to layout the plane, then the name tool to rename it "GND",
Then hit ratsnest to see the result.

If handling high currents you'll need to uncheck "thermals" in the info page
for the plane.

Many Eagle tutorials are out there on the web.

Gridded ground planes are visually confusing while laying out, if you need a grid
enable it last thing.

Having ground plane on both sides for a 2-layer board means that its easy to get
continuity of ground, but you have to add GND vias between them explicitly.