Composition and method for stripping tin or tin-lead alloy from copper surfaces
US5017267A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1990 |
| Grant date | May 21, 1991 |
| Priority date | — |
| Expiry date | Jul 17, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/067
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An aqueous composition for stripping tin or solder, as well as any underlying copper-tin alloy, from copper surfaces, containing an alkane sulfonic acid, preferably methane sulfonic acid, ferric nitrate, and a source of chlorate ion. The composition effects stripping without any appreciable formation of sludge or precipitate or suspended particles, and the chlorate component enables significant reduction in the concentration of alkane sulfonic acid otherwise needed for the stripping. Also described are stripping compositions containing a source of chlorate ion and an acid for solubilizing stripped tin or tin-lead, such as alkane sulfonic acid, acetic acid, formic acid and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.