Eching

[KFC]

I don't get what I'm suppose to do in the beginning of this:

 

http://max8888.orcon.net.nz/pcbs.htm

 

Some thing with soap water and a hot iron?

[Coolphreak]

here's a slightly different way to do it (pretty much the same though)

 

print out ur circuit design on transparent paper...put the transparent paper onto the copper board and then shine an ultra violet light through for about 12 min (with the layout on top). Afer that, put it in some developer solution and water (warm i THINK...not 100% sure) the ratio is about 1 part developer to 5 parts water (1:5). Use a little sponge brush thing to help take off the resist. The water is to dilute the developer, be careful...if there is too much developer, your design might get ruined. After you see your design take it out and apply some acetone to the back (where there is no design) to take off the extra copper resist. Next...mix about 125 grams of sodium persulfate in about 0.5 L of water. Put this solution on a hot plate (i don't think it should be boiling though...just warm it up...maybe it should be boiling? just try it warm first). Use the little sponge brush thing to take off the remaining resist...all the copper should go away (except for your design) and there should be yellow showing through. little bubbles will appear so brush them with ur sponge brush. keep flipping the circuit board in the solution. after you're done apply some acetone to the front (side with the layout) and that should remove the remaining copper resist...

 

hope that helps!