Homebrew_PCBs

On 17/02/14 01:15, Russell Shaw wrote:

> Foaming is usually a sign the liquid viscosity is too high. Long etching times
> are a symptom of that too.

That's interesting - I've never seen viscosity mentioned as a control
parameter for cupric chloride etchant.

> The active ingredient should be diluted 1:1 with water. Add a few percent (like
> half a cup) of hydrochloric acid too. When topping up is need every few months,
> just add more hardware shop hydrochloric acid (it has water in it anyway).

Are you suggesting I dilute the etchant I have one-to-one with water?
That sounds like it'd send the specific gravity crashing through the floor.

I'd sooner add peroxide to it, at least that'll oxygenate it while it's
reducing the SG...

> With a setup similar to yours (but working properly), full etch happens in
> 12mins at room temperature.

I'd consider that more than acceptable seeing as my ferric chloride tank
takes a little over twenty minutes :)

Thanks,
--
Phil.
ygroups@...
http://www.philpem.me.uk/