Underfill method
US7331106B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 2006 |
| Grant date | Feb 19, 2008 |
| Priority date | — |
| Expiry date | May 15, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49179
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for selectively depositing a filled underfill material onto a die surface without covering solder bumps present on the die. The process entails microjetting a polymer matrix material, a filler material, and optionally a fluxing material onto the die surface. Together, the polymer matrix and filler materials define the filled underfill material in which the filler material is dispersed to reduce the coefficient of thermal expansion of the underfill material. The resulting underfill material surrounds but does not cover the solder bumps. The die is then placed on a substrate on which a second underfill material is present, forming a composite underfill layer that completely fills the space between the die and substrate and forms a fillet on a peripheral wall of the die.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.