Electroless gold plating bath and method of using same
US5130168A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1989 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | May 15, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C18/44
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electroless gold plating composition comprises an aqueous solution of alkali metal gold cyanide, alkali metal cyanide, alkali metal hydroxide, a reducer selected from borohydrides and alkyl amine boranes, and a stabilizer having the formula ##STR1## wherein R.sub.1 is --COOH, --OH, --CH.sub.2 OH, or --SO.sub.3 H (or an alkali metal salt thereof), R.sub.2 is --COOH, --OH, --Cl, --H, (or an alkali metal salt thereof) and is disposed in the 2, 5, or 6 ring position, and --NO.sub.2 is in the 3 or 4 ring position. This composition has a pH of 12.5-14.0, is heated at 85.degree.-95.degree. C., and operates at an oxidation/reduction potential of -550 to -700 millivolts to produce high purity gold deposits of amorphous structure and good hardness for electronic applications. The composition may be replenished as many as ten turnovers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.