Homebrew PCBs

mumin55555 wrote:
> i tried for the first time to use ammonium persulphate instead of
> ferric chloride. i built a nice etcing tank with a heater at about
> 50 degree celcius and an air pump. i used about 1kg of ammonium
> persulphate with 2 litre of water (at the first place i used much
> less ammonium persulphate, but when i saw nothing is happening i put
> more).
> help!!!!!!!!!!!!! i need it very urgent!
> thanks a lot,
> mumin.

I get good results with ammonium persulphate, I use 1 part crystals to 5
parts hot water (75 deg C) as per the directions on the bottle I have. Your
agitation and heating should help speed the etching. Don't make it too
strong. Give it some time, don't just start throwing in more crystals.

Hope that helps
Dean