Method of etching circuit boards and recovering copper from the spent etch solutions
US4378270A · kind A · utility
21Cited by
1References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 29, 1981 |
| Grant date | Mar 29, 1983 |
| Priority date | — |
| Expiry date | Oct 29, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25C1/12
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention relates to a method of etching copper with a hydrogen peroxide-sulfuric acid etchant containing an acid soluble phosphonic acid in the manufacture of electronic circuits utilizing a masked copper surface and to a method of recovering the copper from the spent etch solution by electrolysis in solid continuous form saleable as electrolytic copper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.