Method of forming BGA interconnections having mixed solder profiles
US6541857B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 2001 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Jan 4, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of forming BGA interconnections having improved fatigue life is disclosed. In particular, a combination of mask-defined and pad-defined solder joints are selectively positioned within the BGA package. The mask-defined solder joints possess a high equilibrium height, which forces the pad-defined solder joints to elongate, thereby making the pad-defined solder joints more compliant. Further, the pad-defined solder joints possess a slightly longer fatigue life because the stress concentrations found in the mask-defined solder joints are not present in the pad-defined solder joints. Therefore, the fatigue life of BGA packages is increased by implementing a majority of mask-defined solder joints to maintain a high equilibrium height, and selectively placing pad-defined solder joints in high stress areas of the BGA package.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.