etchants

For etching PCBs, what is a) the best, and b) the most gruesome, mixture that you have attempted to use?
I'll start the ball rolling with a) ammonium persulphate, it's fast, clean, see-thru', and you can get the waste products to crystallise out and keep all the active stuff!
And b) weedkiller (chlorate) and battery acid, it's fast, suffers from thermal runaway, is liable to explode, sets fire to most anything that'll burn, and if the fire dont get ya, the fumes will. (Believe this,DON'T try it)
I shall be interested to see how ferric bloody chloride makes out.

I have always used Ferric Chloride. It is nasty stuff.

The EE department a the U I attended used Feric Chloride in a spray etcher they build. It was a crusty mess. I have always used a small glass pan.

The last time I etched I did the **broken link removed** thing. Used rubber gloves and Ferric Chloride on a sponge to wipe the copper from the board. It was fast and worked well. Easy cleanup. I do not know if it works with ammonium persulphate.

Pcb Etching

spuffock said:

For etching PCBs, what is a) the best, and b) the most gruesome, mixture that you have attempted to use?
I'll start the ball rolling with a) ammonium persulphate, it's fast, clean, see-thru', and you can get the waste products to crystallise out and keep all the active stuff!
And b) weedkiller (chlorate) and battery acid, it's fast, suffers from thermal runaway, is liable to explode, sets fire to most anything that'll burn, and if the fire dont get ya, the fumes will. (Believe this,DON'T try it)
I shall be interested to see how ferric bloody chloride makes out.

Click to expand...

Hi, for many years I've been using the VERY MESSY Ferric Chloride. During a visit to a company that produces pcb s commercially, the owner was kind enough to tell me to rather use dilute Hydrochloric Acid (pool acid diluted with 2 parts of water). Then add a little Copper sulphate and stir until dissolved and the solution appears light green (Like cream soda cold drink!). Further, a dash of Hydrogen peroxide (40 volume or more) is added to the mix.

This solution produces virtually NO fumes, is transparent and takes about the same time to etch as your regular ferric chloride. It eventually also becomes dark with the dissolved copper from your board(s), but the addition of another dash of hydrogen peroxide clears it again and you may proceed with a transparent liquid! What's more, when you are finished, just store the used liquid until next time and repeat above steps. VERY ECONOMIC and very clean! I'll NEVER use ferric chloride again if I could help it!
Good luck!

The copper sulphate is not needed, start with the acid and peroxide. Once started, bubbling air through the mixture will regenerate it, although a dash of peroxide does it quicker. All it uses up is acid and air!