Fall 1991

Further Aspects of Ferric Chloride Regeneration

Etchant regeneration is the process by which "spent" etchants are oxidised back to a reuseable form. In an etching facility, the need to regenerate (or dispose ofand replace) an etchant, through "contamination" by the increasing concentration of byproducts, is typified by slower etch rates and poorer quality finishes"); both unacceptable features in a commercial operation. Owing to the increasing public concern for the environment, in terms of polluting it and an awareness of using up finite resources, disposal is becoming less desirable and, through legislation, more restrictive and, therefore, more expensive. Regeneration is the obvious answer to the problem, but it is advisable to be aware of the stage at which regeneration becomes more economical than disposal. Such aspects were addressed in an earlier work on etchant regeneration systems") of which this paper is effectively an extension.

David M. Allen and Heather J.A. White, Cranfield Institute of Technology