Revolutionary!

PCB etched with plain salt! Electrochemical (anodic) etching.

First test setup:

– 5% Sodium Chloride NaCl (as table salt) solution
– Warm water ca. 60°C starting temperature
– Stirring (magnetic stir bar)
– 17V DC, 1 .. 5A
– Copper clad PCB as anode with Toner Pattern (HowTo)
– Copper clad PCB also as cathode.
– measured pH 6,8 about neutral.

Here it´s only done on a scrap sample, but hey – better than expected!
The reddish slur on the bottom of the jar seems to be Cu2O, maybe with CuOH and not metallic Cu (what I wrote first)..
No toxic blue waste water! (Blue is the colour of copper in solution.). We want the copper in the residue and not in solution.
.. I will find out it turns blueish after a while. Must be some interaction with the chloride ions. Must investigate further. But in the end, I dont care  because all dissolved copper will end up on the cathode in the next electrolysis.  Btw.  the white fog is caused by the table salt, it contains a small amount of insoluble anticaking agents.

Reaction Scheme – First Preview

Etching Setup 0

Etching Jar CloseUp

CloseUp of the PCB

The red slurry Residue

Resulting PCB

Unetched PCB

Etched_Sample_1

Still foggy Copper everywhere..

Some hours later there is BLUE 🙁