Method of making an air tight cavity in an assembly package
US5801074A · kind A · utility
Inventors
Key dates
| Filing date | Feb 20, 1996 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Feb 20, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/163
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of making an assembly package having an airtight cavity for housing an electrical element, such as a semiconductor chip. The method includes bonding a shell to a conductive base with a thermally setting alpha-staged epoxy resin which is characterized as being a gel in the uncured state at room temperature. The use of the alpha-staged epoxy resin, in contrast with the conventional beta-staged epoxy resin, results in an airtight cavity being formed without punctures or fissures in the epoxy resin. The method also provides a two-step heating process whereby the epoxy resin is cured at a first elevated temperature in the open atmosphere and further cured and stabilized at a second elevated temperature in a closed environment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.