Electroplated gold-copper-silver alloys
US5256275A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 15, 1992 |
| Grant date | Oct 26, 1993 |
| Priority date | — |
| Expiry date | Apr 15, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D3/62
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A solution for electroplating gold-copper-silver alloys. The solution comprises gold, copper and silver, each in the form of a cyanide complex. The solution further comprises a divalent sulfur compound capable of brightening and leveling the electroplated deposit of the gold-copper-silver alloy. Optionally, a source of cyanide ions such as a free alkali cyanide, is included in the solution. In addition, additives such as surface active agents, buffers and/or conductivity salts may also be included to impart a particular feature or characteristic to the solution. The invention additionally comprises a process for electroplating up to about 20 microns of a gold-copper-silver alloy upon a substrate utilizing these novel solutions. The alloy is deposited upon a substrate which is immersed in the solution, by electroplating at a current density of between about 1 and 15 ASF, a pH of between about 8-11 at a temperature of between about 100.degree.-170.degree. F. for a time sufficient to obtain the desired thickness. Improved brightness results are obtained with the process of the invention by manipulating the electroplating current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.