In the past I used Ferric Chloride. My recent PCB-DIY adventures are
just beginning. At present I am using a mixture of ferric chloride and
citric acid, which is widely known as Edinburgh Etch.
I followed this material:
http://www.nontoxicprint.com/etchcopperandbrass.htm "4 liters ferric chloride solution + 1 liter hot water mixed with
300ml citric acid powder (ratio 3:1) = Edinburgh Etch"
This is citric acid powder by volume. To make half of my Ferric
Chloride in this way I need 1/16th of this. So my mixture is:
250ml Ferric Chloride solution from
http://www.altronics.com.au 62.5ml hot water mixed with 18.75 ml by volume of citric acid powder.
I have little experience with this so far.
In the "Magnetic drive pumps for spray etchers" thread Derward Myrick
wrote that he uses muriatic acid (HCl, hydrochloric acid) because he can
see the board as it etches.
I guess the topic of etchants has been discussed many times. Does
anyone have any views on Edinburgh Etch? There are claims that it can
have a very long life.
Is hydrochloric acid used on its own, with dilution with water, or with
hydrogen peroxide (H2O2)?
http://joshuagalloway.com/pcb.html Two parts 3% H2O2 to one part 31.5% HCl.
I imagine the transparency of the etchant would be helpful. However,
does the etching process leave a residue on the board? I think one of
the claims about Edinburgh Etch is that it doesn't leave any residue.
- Robin
http://www.firstpr.com.au/pcb-diy/ - Robin