Piezoelectric resonator including an acoustic reflector portion
US7868519B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 1, 2010 |
| Grant date | Jan 11, 2011 |
| Priority date | — |
| Expiry date | Mar 1, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/02133
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A piezoelectric resonator that achieves stable quality and improved resonance characteristics includes an acoustic reflector portion disposed between a substrate and a vibration portion, which includes a piezoelectric thin film sandwiched between a pair of electrodes, and a plurality of low acoustic impedance layers made of a material having relatively low acoustic impedance and a plurality of high acoustic impedance layers formed made of a material having relatively high acoustic impedance, the acoustic impedance layers being disposed alternately, and adjustment layers, which are disposed between the high acoustic impedance layers and the low acoustic impedance layers on the substrate sides of the high acoustic impedance layers and which have an acoustic impedance value intermediate between that of the high acoustic impedance layers and that of the low acoustic impedance layers. The low acoustic impedance layers and the high acoustic impedance layers have compressive stresses and the adjustment layers have a tensile stress.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.