Electrochemical etch for high tin solder bumps
US6468413B1 · kind B1 · utility
11Cited by
6References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2000 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Apr 18, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/10253
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An aqueous electrochemical etchant for etching metals in the presence of one or more metals not to be etched, the etchant including glycerol in the concentration range of 1.30 to 1.70 M, a sulfate compound having a sulfate ion concentration in the range of 0 to 0.5 M, and a phosphate compound having a phosphate ion concentration in the range of 0.1 to 0.5 M.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.