Russell Shaw wrote:
>>Phil wrote:
>>
>>
>>
>>>Very nice site! It would have been very helpfull when I was trying CuCl.
>
>
> ...
> Adam Seychell wrote:
> > Thats interesting your experience were different than what I measured in
> > my test. The bubbles agitation for my test was very vigorous, so maybe
> > that had something to do with it. The FeCl3 was full strength as sold
> > industrially (sp.gr=1.47), the AP was 200g/l almost fresh (very faint
> > blue color due to previous tests). For AP I was getting about 9 minutes
> > with 1oz copper at 42°C. 5 minutes sounds fast! Two possible reasons:
> > you unknowingly have "1/2 oz" PCB material, or the ferric chloride you
> > were using was for some reason not very potent which made it slow in
> > comparison. I'm equally curious becuase it could mean my test results
> > are botched.
> >
> > If you have access to a micrometer caliper, you can peal copper away
> > from the board using a heat gun and pair of pliers, burn off the
> > remaining epoxy stuck to the back of the foil, and measure its thickness
> >
> > Adam
>
> Ferric chloride works faster if it is diluted with water (to 1 part or 2
> parts water). A properly cleaned 35um copper pcb should etch in 5 minutes
> at room temperature with gentle/moderate bubble agitation.
>
yep, 5~6 minutes sounds ok for FeCl. But I didn't think AP at 45°C
wouldn't be that fast as Phil is finding, maybe at 70°C however.
> http://www.jtbaker.com/msds/englishhtml/f1060.htm
Thats a good link on FeCl. They say diluting 1 part FeCl (sp.gr 1.47) to
2 parts water doesn't effect etch rate. I didn't try diluting it. I
can't be bothered repeating all the experiments again :(.
Adam