Removal of orthophosphite ions from electroless nickel plating baths
US6048585A · kind A · utility
7Cited by
5References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1998 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Jan 25, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C18/36
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Orthophosphite ions produced by oxidation of hypophosphite in an electroless nickel plating bath can be removed by precipitation with an alkali metal or alkaline earth metal cation such as calcium. In order to avoid the precipitation of calcium sulfate and the generation of large amounts of particulates in the bath, nickel sulfate can be replaced by a nickel salt of an alkylsulfonic acid or hypophosphorous acid, whose anion forms a soluble salt with an alkali metal or alkaline earth metal cation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.