The original question asked was: Can anyone post here the formula for Cupric Chloride etch and Ammoniacal Etch? I know that Hydrochloric Acid and Hydrogen Peroxide are used in Cupric Chloride etch but I can't find any formula in my personal meager library. Thanks... [log in to unmask] Reply: Look in Coombs, Handbook of Printed Circuits 3 rd edition on page 14.15 at paragraph 14.4.3 for the chemical reactions for cupric . The alkaline chemistry is on page 14.10. Hydrochloric acid and Hydrogen peroxide or sodium hypochlorite are listed as means to regenerate the cupric chloride etchant. Only personnel with proper equipment and that definitely includes very good ventilation with a fume scrubber on the ventilation sustem, and more importantly a good understanding should attempt to do this as the reaction basically involves the creation of chlorine gas in the solution and you do not want this nasty chemical in your breathing area Chlorine gas really can kill you, and if it does not get you when you breath it can cause chemical pneumonia ---------- From: [log in to unmask] To: [log in to unmask] Subject: Re: FAB: Formula for Etching Date: Monday, September 23, 1996 10:10PM John: I think you are a little confused, and if you try playing around with HCl and peroxide, you are going to die, along with some of the people near you. Suggest that you look at the website: http://www.pcbfab.com and look up the sections on etching, both innerlayer and outerlayer. This may assist in understanding what the chemistry of the etchants is all about. Your inquiry sounded like you want to make your own, and if so, read carefully, and be real real careful. This stuff can kill. Good luck Rudy Sedlak RD Chemical Company [log in to unmask] phone 415-962-8004 *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************