Economic Aspects of Regeneration of Etchants

The chemical machining industry, as well as the printed circuit industry, have long considered etching the backbone of the process. Consequently, much emphasis has been put into reducing etchant costs, refining process controls, and reducing equipment downtime. The search for a method to address these problems resulted in the birth of etchant regeneration. Regeneration, as the name implies, is a process used for keeping the etchant bath fresh or as close to fresh as possible. This paper will discuss the regeneration of cupric chloride when etching copper and copper alloys, and ferric chloride when etching steel and steel alloys.