Homebrew PCBs

On 08/05/12 23:39, poofjunior wrote:
> Hi everyone,
>
> I noticed that a few people have mentioned regenerating a cupric chloride
> etching solution with a few options: aerating it with a fish pump, adding
> Hydrogen Peroxide, or even using some form of electrolysis.
>
> Has anyone had any long-term success with this process?  How long does it
> take to aerate?  Is there any excess waste that needs to be dumped
> eventually?

No.

> Are there any circuits I can create to duplicate an electrolysis setup?
>
> I'd greatly appreciate more details on anyone's success or any insights on
> maintaining a CuCl2 solution for use over and over again.  If I can duplicate
> a setup, or make my own, I'd be happy to write up a tutorial.

Ferric chloride is commonly known as Profloc-F for floculating in sewer treatment.

You shouldn't dispose of ferric chloride if using air agitation such as 
bubbling, because it'll eventually turn green and work as copper-chloride etcher 
and last forever (the oxygenation is needed iirc). My etchant is years old and 
still working well.

I use a bubble etcher same as the first in this list:

   http://www.esr.co.uk/electronics/pcb-tanks.htm

The only aeration that's needed happens during etching anyway.

That one comes with a heater, but i get a complete etch of double-side pcb at 
room temperature in ~12mins.

Just keep the stuff topped up with hydrochloric acid every few months and it'll 
work well instead of the water evaporating out. Keep a cover over the container 
when not in use.

When starting with new ferric chloride, first dilute it 1:1 with water, then put 
a bit (like half a cup per litre) of hydrochloric acid in it.

Copper saturated etchant is excellent weed killer. Apply only selectively, or 
you'll end up with a large black spot on the lawn.