Structure to accommodate increase in volume expansion during solder reflow
US6686664B2 · kind B2 · utility
6Cited by
5References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 30, 2001 |
| Grant date | Feb 3, 2004 |
| Priority date | — |
| Expiry date | Oct 20, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49171
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Solder balls, such as, low melt C4 solder balls undergo volume expansion during reflow. Where the solder balls are encapsulated, expansion pressure can cause damage to device integrity. A volume expansion region in the semiconductor chip substrate beneath each of the solder balls accommodates volume expansion. Air-cushioned diaphgrams, deformable materials and non-wettable surfaces may be used to permit return of the solder during cooling to its original site. A porous medium with voids sufficient to accommodate expansion may also be used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.