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