Regeneration of spent ferric chloride etchants.

摘要

Spent ferric chloride etching compositions are regenerated by electrolysis which includes introducing spent ferric chloride etching composition containing total iron content substantially equal to the original total iron content of fresh etching composition into the anode compartment of an electrolysis cell that contains an anode compartment, a cathode compartment, and an anion-exchange membrane separating the compartments, and applying voltage of +0.6 to +1.5 volts versus a saturated calomel electrode to the anode.