Homebrew PCBs

Simao Cardoso wrote:
> What i had in mind was a copper electro winning system based on platinum
> anode and copper/steel/titanium plates for cathode, it will deposit
> copper and regenerate the persulfate 'from the sulfate' again. 

I think you better first know if you can achieve high enough ratio of 
S2O8/SO4 using such an etch tank configuration. Remember, you are 
competing with electrolysis of water. Expect electrolysis efficiency to 
go through the floor without any S2O8 salt isolation.

> I really want metallic resist because dry film covering the holes gives
> much work and don't has the enough successful rate. 

You may find as I eventually did after several years of home PTH 
plating, that the additional complexity of operating and maintaining a 
metal plating resist tank (acid tin sulphate or tin/lead fluroborates ) 
far out ways the minor problems with hole tenting. You just have shape 
up on your drilling skills a little more.
There is also other problems that come with hobby pattern plating PCBs, 
such as copper surface residues after photoresist developing, use of 
complex controlled alkaline etchants and tin metal attack in NaOH 
photoresist strippers.

Best of luck.

Adam.