Wafer level packaging of materials with different coefficients of thermal expansion
US7635636B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 2006 |
| Grant date | Dec 22, 2009 |
| Priority date | — |
| Expiry date | Mar 26, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/059
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electro-mechanical device package includes a cap material permanently bonded to a device wafer encapsulating an electromechanical device. An intermediate material is used to bond the device and capping material together at a low temperature, and a structure including the intermediate material emanating from either the device or cap material, or both, provides an interlocking at the bonding interface. One package includes a reusable carrier wafer with a similar coefficient of thermal expansion as a mating material and a low cost cap wafer of different material than the device wafer. A method for temporarily bonding the cap material to the carrier wafer includes attaching the cap material to the carrier wafer and is then singulated to mitigate thermal expansion mismatch with the device wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.