On Wed, 6 Mar 2019 01:16:01 +1100, you wrote:
On 05/03/19 22:26, MVS Sarma wrote:
Ferric chloride disposal is a a cumber some affair.
?Most Indian PCB makers appear to be using HCL and h2o2.
Ammonium per oxide, i bought a bottle, but never used.
Till now only Ferric chloride . Working OK? for me for my hobby use.
There is no need to *ever* dispose of Ferric chloride.
The Ferric Chloride eventually becomes CuCl, but will run out of
Chloride, hence adding HCL is needed. In the HCL/H2O2, you start out
with enough oxygen from the H2O2, run out of that, then bubble. You
really ought to bubble in the first place, since it keeps the etchant
moving. I don't think that the Iron ions do very much, they may plate
back onto the board, but have no structural strength and fall off.
No real need for Ferric Chloride in the first place, though.
CuCl stains less, for some reason.
Harvey
Start with it diluted 1:1 with water, and just add some HCl every time you use
it. Keep the Ferric chloride covered when not in use.
Use air bubble agitation, because the dissolved oxygen regenerates it.
