Thin film piezoelectric vibrator, thin film piezoelectric bulk acoustic wave resonator, and radio-frequency filter using such resonator
US7940145B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 2007 |
| Grant date | May 10, 2011 |
| Priority date | — |
| Expiry date | Apr 16, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2009/241
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A thin film piezoelectric bulk acoustic wave resonator has a multilayer structure including a piezoelectric thin film, a first metal electrode film, and a second metal electrode film. At least a part of the piezoelectric thin film is interposed between the first and second metal electrodes. A resonance part and a connection part are formed on an insulating substrate as films by a thin film forming apparatus. The resonance part vibrates in radial extension mode with a center of the piezoelectric thin film used as a node, the piezoelectric thin film of two resonance parts is polarized in a direction perpendicular to a film surface, and a width of the connection part is one-fourth or less of a width of two resonance parts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.