Wafer-level surface acoustic wave filter package with temperature-compensating characteristics
US7230512B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 2004 |
| Grant date | Jun 12, 2007 |
| Priority date | — |
| Expiry date | Aug 19, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/1071
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A SAW filter is fabricated at a wafer level for providing desirable temperature characteristics. The filter includes a piezoelectric substrate bonded to a carrier substrate, wherein the coefficient of thermal expansion of the carrier substrate is less than the coefficient of thermal expansion of the piezoelectric substrate. Interdigital transducers are formed on the piezoelectric substrate so as to form a SAW composite die structure. A cap substrate having a coefficient of thermal expansion similar to that of the carrier substrate is bonded to the SAW composite die structure for enclosing the interdigital transducers. Plated vias form signal pad interconnects to input and output pads of the interdigital transducer and a sealing pad formed on the surface of the piezoelectric substrate bonds the SAW composite die structure to the cap substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.