Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Hi,
Back in the 70's and 80's I etched several hundred boards using Shipley's AZ111 positive photo resist. Recently I have started to build some boards again using toner method but would like more accuracy.

I have looked all over the net and can't seem to find the AZ111 anymore. Does anyone know of an equivalent available product that you can buy in small quantities.

Last time I purchased AZ111 it was about $60 per qt. but that was in the 70's.

The AZ111 worked great. For two sided boards I would spin coat one side bake for 15 minutss, spin coat and bake the other side, then UV expose with a film maste and etch. Shipley had a sodium carbonate develop that worked well, no brushing or wiping was necessary. For etching I initially used ferric chloride but switched to heated ammonium persulfate spiked with touch of mercury chloride. The persulfate was much cleaner to work with and would etch a board in 20 seconds in my splash tank.

The only issue was the spin coating which limited the board size and shape to about 8-10" sq.max. Long narrow boards were a problem to get coated evenly. I never tried spray or dip coating.

Craig