I hope you don't mean you plan to etch with a Cupric Chloride bath and
will use HCl and H2O2 to regenerate it. If not the combination of these
two chemicals will result in the evolution of chlorine and should only
be done in a very controlled way.
	
        There is a lot of work that has been done on Cupric systems with
and without the addition of Sodium Chloride and some modifiers to help
with the stability of the bath. There are a host of resists optimized
for Acid etching and most shops use cupric for  l inner layers.
        One significant difference between Ammonical systems and acid is
speed , the acid are classically slower. Slower is bad for production
but can be a good thing for edge definition and resolution. Cupric is
fairly easy to regenerate in house and waste treatment is also fairly
easy . Ammonical on the other hand is usually sent out for reclaim and
is difficult to treat in house. There are a few reclaim systems out
there that are designed to regenerate the solution you might ask around
for who is using them and how do they work.
        Finally with Ammonical etch systems you have a variety of etch
resists to use including tin, tin/lead/oxide/resists/ etc. with Acid
systems you are fairly limited to resists of various types and
application methods , as well as gold and a few other metals.

        SO the decision should be based on a few criteria:
                1) Type of surface to etch ( inner layer , outerlayer)
                2) Waste reduction, handling Governmental issues
                3) Production, thru put
                4) Equipment to use ( Ammonical systems need  controlled
venting to be stable)

        There are some great sources of info out there including
chemical and equipment suppliers. I am sure that a lot of them are on
the Net and would be more than willing to give you all the info you
need.

From: Tomer_2
To: [log in to unmask]
Subject: [TN] Acid Etching
Date: Thursday, April 02, 1998 4:39PM

Technetters,
I'm in the process of gathering information on Acid Etching,
Hence I'm looking for any reference information, articles etc.
 
The compositions of the solution ( we intend to use )are Hcl and H2O2.
What is the basic etching reaction ?
What is the basic differences between Acid and Alkaline Ammonia  etching
( Etching rate, etc.) ?
Any recommendation for the make up and operating procedures ?
Any user experience of basic well known problems, we supose to meet ?
Any response would be appreciated.
Tomer
 
 
 
 

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