width of routing trace

[caringin]

Hi,

I'd like to design a PCB (single layer) using Protel99_SE. I'm still confused, how is the preferred of the width of routing trace for signal and power? How to set it in Protel99_SE? And how to create ground plane? Thanks.

 

[wwfeda]

Normally I put my traces as wide as possible for the power lines. Usually 100 mils if possible. When it branches into the circuit area, I use thinner traces like 20 or 30mils.
You can change the units by pressing 'q' from mils to millimeters and vice versa.

To set ground planes, you click on the polygon toolset with the name 'placepolygonplane' and select the area you want the ground to be in. A box will appear and on the net, select ground. Make the width 10mils and grid size 8mil. This ensures your ground plane is totally connected.

To change the track width, you can start drawing a trace, then press tab to change the width. Or you can set it at the preference rules part.

Also if you need 50 ohms impedance traces, you will need around 40 to 60 mils traces. This depends on the board thickness that you are using and if your board are two sided or not. But setting it to 50mils thick is a good start. This is only important if you are doing high frequency stuff.