I need to etch a PCB

Wig

I've made a PCB (Printed Circuit Board) in my education days, but I don't have access to the equipment now.

I have a PCB to make about 4 x 3 inches, and I'm wondering if any one has some ideas about how to get a single board done as cheaply as possible. I've thought about asking the local University, if they would let me use their equipment, but I need other ideas to fall back on if I can't do it at the Uni.

And I've forgotten, how do you transfer the circuit pattern onto the board so that the acid does not dissolve the copper?

tom9980

Quick google and i found this on youtube

http://www.youtube.com/watch?v=Vlui7s4lj7g&NR=1

http://www.youtube.com/watch?v=urv6jArKp6M

Wig

Good find, thanks, Youtube is full of good stuff.

isofa

You need to use an etch resist pen to draw the circuit onto the copper - such as this one from maplin: http://www.maplin.co.uk/Module.aspx?ModuleNo=2104

(Or develop a transparency printed with the circuit design onto the copper using etch resist ink)

The etch away the copper using ferric chloride solution (crystals or made up solutions available from most electronic stores, including Maplin).

Only just disposed on mine from old school days after a big clear out, otherwise could have popped it all in the post!

Stompa

Wig wrote: »

And I've forgotten, how do you transfer the circuit pattern onto the board so that the acid does not dissolve the copper?

I've probably not etched a board for about 25 years, but you used to be able to get some letraset like transfers (in various shapes, lines, pads, etc...) that you'd apply manually to the surface of the board. Then etch in ferric chloride, and hope that the transfers didn't float off!

Looks like there are easier ways these days though, for example:

http://www.semis.demon.co.uk/PCB/PCB.html

Wig

I think I used this UV method in college but I can't remember how we printed onto the transparent paper/film. I'd be surprised if we had a laser printer in those days.

Stompa wrote: »

Looks like there are easier ways these days though, for example:

http://www.semis.demon.co.uk/PCB/PCB.html

That blue paper is still available from Maplin, but it seems to be a commercialised version of using a laser printer onto normal glossy photo paper. I think I'll use the glossy photo paper method.

Fifer

For a simple single board, drawing the tracks with an etch resist pen, then etch with ferric chloride solution is is probably simplest (as suggested by isofa).

unrich

I think Maplin still sell the stuff to do this.