Electroless gold plating solution
US5470381A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1994 |
| Grant date | Nov 28, 1995 |
| Priority date | — |
| Expiry date | Jul 22, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C18/44
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electroless gold plating solution comprising an aqueous solution containing as ingredients (a) chloroauric (III) acid or a salt thereof or a sulfite or thiosulfate gold (I) complex salt as a gold source, (b) an alkali metal or ammonium sulfite or thiosulfate, (c) ascorbic acid or a salt thereof and (d) a pH buffer, characterized in that (e) a compound selected from 2-mercaptobenzothiazole, 6-ethoxy-2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and salts thereof, and optionally (f) an alkylamine compound are further incorporated. The solution prevents the bath made up thereof from forming any precipitate during the storage and usage of the bath and the bath can be stably used for long periods of time. Furthermore, the bath gives a significantly high plating rate, which does not decrease even at high bath loads. Thus the bath renders it possible to plate a number of substrate items within a short period of time and also to perform thick plating within a short period of time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.