Method and apparatus for forming bump structure used for flip-chip mounting, the bump structure and the flip-chip
US5633204A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/3025
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A bump structure has a bump constituted by a metal projection which is formed on an electrode of a substrate, and a solder which covers the metal projection but does not touch the electrode. The metal projection is substantially spherical and has a projected portion at a center portion on an upper surface thereof. The metal projection is made of a metal having properties of solder diffusion prevention and adhesion to solder. The bump structure may have two bumps, the first bump being substantially the same as the bump described above and the second being such that its diameter is smaller than an outer diameter of the first bump and it covers the projected portion on the first bump. This bump structure can be formed using a simple process, and can be applied to flip-chip mounting in semiconductor devices with high reliability and yield.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.