Under-bump-metallurgy layer for improving adhesion
US6891274B2 · kind B2 · utility
3Cited by
12References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 18, 2003 |
| Grant date | May 10, 2005 |
| Priority date | — |
| Expiry date | Aug 18, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/14
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An under-bump-metallurgy layer is provided. The under-bump-metallurgy layer is formed over the contact pad of a chip and a welding lump is formed over the under-ball-metallurgy layer. The under-bump-metallurgy layer comprises an adhesion layer, a barrier layer and a wettable layer. The adhesion layer is directly formed over the contact pad. The barrier layer made from a material such as nickel-vanadium alloy is formed over the adhesion layer. The wettable layer made from a material such as copper is formed over the barrier layer. The wettable layer has an overall thickness that ranges from about 3 μm to about 8 μm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.