METHOD FOR ELECTROLYTIC RECYCLING AND REGENERATING ACIDIC CUPRIC CHLORIDE ETCHANTS

• Main Author: YE Yiting
• Format: Patent
• Language: English
• Published: 02.03.2017
• Subjects: APPARATUS THEREFOR; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMISTRY; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTIONOF COMPOUNDS OR NON-METALS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METALLURGY; PRINTED CIRCUITS

A method for electrolytic recycling and regenerating acidic cupric chloride etchants, comprising: (1) employing an acidic cupric chloride etchant that contains iron ions in PCB etching, controlling the oxidation-reduction potential (ORP) of said acidic cupric chloride etchant within the range of 360-700 mV; (2) transferring an etchant waste of step (1) to an electrolysis tank and electrolysing said etchant waste; (3) the chlorine gas generated by electrolysis oxidizes the electrolyte in the electrolysis tank and thereby dissolved into the electrolyte, in the effect of the ORP of the electrolyte; (4) regenerating an etchant by oxidizing Fe(II) ions and Cu(I) ions in the electrolyte to Fe(III) ions and Cu(II) ions using the chlorine gas of step (3) that is dissolved into the electrolyte, and when the chlorine gas is fully dissolved into the electrolyte, the oxidizing step of the electrolyte is finished and an etchant is regenerated; (5) transferring the etchant regenerated in step (4) to an etching production line.