Immersion tin silver plating in electronics manufacture
US9175400B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2009 |
| Grant date | Nov 3, 2015 |
| Priority date | — |
| Expiry date | Jun 12, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12715
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method is provided for depositing a whisker resistant tin-based coating layer on a surface of a copper substrate. The method is useful for preparing an article comprising a copper substrate having a surface; and a tin-based coating layer on the surface of the substrate, wherein the tin-based coating layer has a thickness between 0.5 micrometers and 1.5 micrometers and has a resistance to formation of copper-tin intermetallics, wherein said resistance to formation of copper-tin intermetallics is characterized in that, upon exposure of the article to at least seven heating and cooling cycles in which each cycle comprises subjecting the article to a temperature of at least 217° C. followed by cooling to a temperature between about 20° C. and about 28° C., there remains a region of the tin coating layer that is free of copper that is at least 0.25 micrometers thick.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.