METHOD FOR TREATING ETCHANT

摘要

In order to ensure an easy operation a decreased cost in maintenance and installation and a safely 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) treating an etchant including copper (1) chloride or ferric chloride containing copper by means of an electrolysis using a diaphragm to withdraw copper electrolytically deposited in a cathode cell, (2) supplying chlorine gas generated in an anode cell into another etchant used in an etching process, thereby enabling the etchant to be regenerated.