Composite solder paste for flip chip bumping
US5803340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1995 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Sep 29, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/0769
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Composite solder paste compositions adapted to be deposited using a dry film photoresist mask to form solder joints for flip chip integrated circuit devices. The composite solder paste compositions are characterized by the ability to flow at a first temperature during bumping reflow while the photoresist mask is present, yet upon subsequently reheating to a higher temperature yield solder joints capable of withstanding temperatures of 200.degree. C. and higher. As such, the present invention retains the advantages associated with using a dry film photoresist as a mask during deposition of the solder, yet results in the formation of solder joints that exhibit enhanced reliability in severe thermal environments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.