3 REGENERATION OF ETCH SOLUTIONS CONTAINING TRIVALENT MANGANESE IN ACID MEDIA

摘要

There is disclosed a method of regenerating an etch solution comprising a metastable complex of manganese (III) ions in a strong acid wherein at least a portion of the manganese (III) ions in the metastable complex are unstable, (II) ions. The method comprising: i) adding an effective amount of a reducing agent to the etching solution; ii) allowing the reducing agent to react with the etching solution to cause the manganese dioxide to dissolve; And iii) applying a current to regenerate the manganese (III) ions in the etching solution.