Method for electrolytic recycling and regenerating acidic cupric chloride etchants
US10443138B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Aug 30, 2016 |
| Grant date | Oct 15, 2019 |
| Priority date | — |
| Expiry date | Feb 20, 2037 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
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 electrolyzing 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.