Double solder bumps on substrates for low temperature flip chip bonding
US8987132B2 · kind B2 · utility
74Cited by
8References
2Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 25, 2014 |
| Grant date | Mar 24, 2015 |
| Priority date | — |
| Expiry date | Aug 25, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/043
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Multiple injections of molten solder are employed to form double solder bumps having outer layers that melt at lower temperatures than the inner portions thereof. During a flip chip assembly process, the reflow temperature is above the melting temperature of the outer layers and below the melting temperature of the inner portions of the solder bumps. As the inner portions of the solder bumps do not collapse during reflow, a flip chip assembly can be made at relatively low temperatures and have a high stand-off height. A structure having double solder bumps facilitates flip chip assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.