Homebrew PCBs

Kim Vellore wrote:
>  
> 
> Wondering why this would be faster than dipping the board in FeCl
> 
> Kim

Unlike persulfates, the FeCl3 and CuCl2 etch reactions produce 
relatively insoluble copper(I) chloride at the surface, which acts as a 
barrier for further etching. Because its a precipitate (as opposed to 
ions), it doesn't easily diffuse into the bulk solution. You can see 
this copper(I) chloride as streaks of white solid when you pull the 
copper out of etchant and hold it for 30 seconds.

 From my experience, I found there isn't much speed improvement between 
decent bubble assisted agitation and manual brushing the PCB surface.

Adam