Non-cyanide electrode cleaning process
US4968397A · kind A · utility
Inventors
Key dates
| Filing date | Nov 27, 1989 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Nov 27, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2224/85011
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electrolytic process employing a water solution of metal lactates or lactic acid and metal hydroxides, rapidly and safely removes metal plating bleed, residual oxides or the like (stains), plastic flash, resin bleed and deflashing media, from electrodes of electronic devices. Anodic etching or a combination of cathodic and anodic etching is preferred. Noble metals are selectively removed without cyanide compounds. For example, excess silver from spot plating on copper leadframes is etched away 2-3 times faster than the underlying copper. After cleaning the device leads are bright, polished, stain-free and without scale, residual plating bleed, deflashing media, plastic flash or resin bleed. The process is effective, less hazardous, easy to use and economical.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.