Process for using persulfate in a low pH etch solution to increase aluminum foil capacitance
US10422050B2 · kind B2 · utility
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16Claims
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Key dates
| Filing date | Mar 15, 2017 |
| Grant date | Sep 24, 2019 |
| Priority date | — |
| Expiry date | Oct 21, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25F3/14
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Anode foil, preferably aluminum anode foil, is etched using a process of treating the foil in an electrolyte bath composition comprising a persulfate, a halide, an oxidizing agent, and a sulfate. An etch resist can be added to the anode foil prior to etching. The anode foil and the attached etch resist can be heated prior to immersing both in an electrolyte bath composition. The anode foil is etched in the electrolyte bath composition by passing a charge through the bath, while maintaining a constant level of persulfate. The etched anode foil is suitable for use in an electrolytic capacitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.