Piezoelectric substrate for a saw device
US7408286B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 2007 |
| Grant date | Aug 5, 2008 |
| Priority date | — |
| Expiry date | Jan 17, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49155
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention provides a composite structure having a supporting substrate between a piezoelectric substrate and a compensation layer. The materials used to form the piezoelectric substrate and the compensation layer in isolation, have higher thermal coefficients of expansion (TCE) relative to the TCE of the materials forming the supporting substrate. Once the composite structure is created, the piezoelectric substrate and compensation layer tend to expand and contract in a similar manner as temperature changes. The expansion and contraction forces applied to the supporting substrate by the piezoelectric substrate due to temperature changes are substantially countered by similar opposing forces applied by the compensation layer, resulting in the opposing forces substantially counteracting one another. Due to the counteraction, the composite structure resists bending or warping, reducing expansion and contraction and increasing stress of the piezoelectric substrate, and thus reducing the effective TCE and TCF of the piezoelectric substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.