Method for forming fine-pitched solder bumps
US6268114A · kind A · utility
67Cited by
5References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1998 |
| Grant date | Jul 31, 2001 |
| Priority date | — |
| Expiry date | Sep 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/014
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming solder balls that have larger spacings between them and electronic devices containing such solder balls are disclosed. In the method, an additional layer of a leachable metal such as gold or silver is used between an under bump metallurgy layer and a solder bump subsequently formed. This allows the formation of the under bump metallurgy layer prior to the deposition of the solder material into a window formed in a photoresist layer. The present invention allows the underfill of a solder window, instead of an overfill which is normally required in a conventional method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.