--- In
Homebrew_PCBs@yahoogroups.com, Piers Goodhew <piers@...> wrote:
>
> Hi All,
>
> What is the term for the process where your traces are simply
> "outlined" by etching, and as a result, most of the copper is left on
> the board, and you presumably use a lot less etchant (and maybe get
> some 2D RF shielding as well).
>
It's called a flood or a copper pour. Both OrCAD and DipTrace refer to it as a pour (I highly recommend DipTrace). You can select which net to connect it too or you can leave it isolated to just save on etching. I always connect mine to ground to create a ground plane on the top surface. It's good for both analog and RF circuitry. Select the pour function and draw the area you want to fill. Usually this would just be the outline of the whole board. From the Pour settings, you can specify the keep-away (the gaps from the traces and objects) and also the size and number of the connections at each node connected to the selected net (say ground). The nice thing about pours (as opposed to planes) is you can make them any shape and you can have more than one on a layer. They're a great way to do split power planes. In this way you can have only a 2 layer board and still have a Vdd and a Ground plane. A copper pour on top with a few vias to the bottom helps give good ground coverage all over the board. I have one picture of a flood posted here ...
http://groups.yahoo.com/group/Homebrew_PCBs/photos/album/1406912540/pic/listNote, I usually use a cross-hatch pattern as this keeps the laser's drum from loading up. I'll try to remember to upload some more images soon.
Phil (KA0HBG)