Method for regenerating etchant.

摘要

In order to ensure an easy operation, a decreased cost in maintenance and installation, and a safety and effective use of chlorine gas generated in a closed system, a new method for treating an etchant is offered. The method comprises the following steps of; 1 pi beta treating an etchant including copper (I) chloride or ferric chloride containing copper by means of an electrolysis using a diaphragm to withdraw copper electrolytically deposited in a cathode cell, 2 pi beta supplying chlorine gas generated in an anode cell into another etchant used in an etching process, thereby enabling the etchant to be regenerated. <IMAGE>