Catalyst solutions for activating non-conductive substrates and electroless plating process
US4863758A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1987 |
| Grant date | Sep 5, 1989 |
| Priority date | — |
| Expiry date | May 13, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/181
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed are an improved activation composition for preparing substrates for metallization in an electroless plating bath. Also disclosed is an improved process for activating substrates prior to metallization and an improved process for metallizing employing the improved activating process. Electroless deposition, which involves chemically reducing ions of the metal to be plated from a plating bath and onto an activated substrate surface, is improved by employing an organic acid in the activating bath which activates the substrate surface. Preferred activating baths contain palladium halide ions to provide a catalytic surface on the substrate, stannous halide ions to provide a protective sol, a source of additional halide ions, and an organic acid such as citric or tartaric acids. The composition and process enable the elimination of a typically-required acceleration step, but yet provide consistently high quality results especially with substrates having through holes requiring coating, such as printed circuit boards requiring a plating of copper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.