Piezoelectric element and touch screen utilizing the same
US7176903B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2004 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Sep 16, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/877
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A piezoelectric element includes a substrate, a lower electrode on the substrate, a piezoelectric layer on the lower electrode, and an upper electrode on the piezoelectric layer. The upper electrode includes a common base and a plurality of parallel branches extending from the base. The branches are arranged at a regular interval or pitch λ1. The lower electrode faces the branches of the upper electrode via the piezoelectric layer. The thickness h of the piezoelectric layer and the branch pitch λ1 are determined to satisfy an inequality 0.005≦h/λ1≦0.1. The lower electrode has a hillock occurrence rate which is no greater than 0.1%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.