PCB Design Considerations

[yano]

I've never designed a PCB before, but I'm starting to work on designing one for a project of mine. Are there any sort of things I should take into account?

For instance, is it OK to run various power traces near each other?
In my case, I have + and -9V running next to each other, and sometimes i have a power lead near ground.

Are things like this OK? Anything else to consider?

[Dai H.]

I believe R.G. Keen has a book on this you can buy from him.

[gez]

One or two tips here:

http://www.expresspcb.com/ExpressPCBHtm/Tips.htm

Go along to your local library.  If it's anything like mine they'll have at least ONE book which covers the basics (even if it's only part of a chapter).  Failing that, take out "Everything is Illuminated" by Jonathan Safran Foer... nothing to do with PCBs, but a good read!

[R.G.]

I've never designed a PCB before, but I'm starting to work on designing one for a project of mine. Are there any sort of things I should take into account?

A huge number of them. Take the suggestion and go get some kind of guide on how to do this. I have a book that narrows the subject to just the simple kinds of PCBs for effects, but most texts will tell you the nitty gritty.

For instance, is it OK to run various power traces near each other?

It's not only OK, it's desirable - if you can manage to do it. Paired power and ground traces carry equal and opposite currents (if you do the layout right) and the area between them has a magnetic field that can induce voltages and currents - feedback that's usually in an unwanted direction. The problem is usually that you *can't* run power and ground in parallel for any significant distance on a single layer board. Double or more layers make this easier.