Method to reduce occurrences of fillet cracking in flip-chip underfill
US6372544B1 · kind B1 · utility
16Cited by
2References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 23, 2000 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Jun 23, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/351
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A softened and compliant fillet portion of a cured polymeric underfill in a flip-chip arrangement reduces occurences of fillet crackings caused by thermal stresses. The softening of the fillet is achieved by chemically breaking cross-links in the cured polymeric underfill material using a chemical solvent. In another embodiment, the softening of the fillet is achieved by applying heat using a controllable beam of thermal energy to break up the cross-links to thereby soften the fillet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.