Etching PCB with HCL and H202

[vick5821]

Hey friends, I discovered that I could actually used HCL and H202 as etchant fo my PCB. But one problem is that I get a normal/standard HCL and H202 will do ? Or any specific concentration ?

http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/

Need some yrgent help cause would go to hardware shop soon !

Thank you for help

 

[gorgon]

When I did this some 40 years ago, I used both HCl and H2O2 at 30% strength. 1 part of each and 3-4 parts water as far as I can remember. Always remember to pour the acid into water, NOT the other way around.

 

[vick5821]

When I did this some 40 years ago, I used both HCl and H2O2 at 30% strength. 1 part of each and 3-4 parts water as far as I can remember. Always remember to pour the acid into water, NOT the other way around.

Pour the acid into the beaker(with water) , then pour H202 you means ? 30% concentation means how many molar ?

Thanks

 

[gorgon]

Correct, always water first. 30% HCl is around 11.2 M. H2O2 I've never used M, only %(volume).

 

[vick5821]

Correct, always water first. 30% HCl is around 11.2 M. H2O2 I've never used M, only %(volume).

If like I go to hardware shop and ask them for HCl, they will give me only one type ..they didnt sell in molar I think. So any will do is it ?

Thank you

 

[(*steve*)]

If you purchase HCl in a form where it is listed with a w/w or % conc then you'll have to do some math to get the molar concentration. Just googling for it will also probably get you the answer.

As Gorgon has suggested 30% is about 11.2M