The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 08, 2012
Filed:
Mar. 10, 2010
Hidekazu Nakanishi, Osaka, JP;
Hiroyuki Nakamura, Osaka, JP;
Yukio Iwasaki, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A surface acoustic wave device includes a piezoelectric element, an IDT electrode formed on the piezoelectric element for exciting a principal wave, a reflection film formed on the piezoelectric element having a higher reflectivity than the reflectivity of the piezoelectric element in a visible light wavelength region, and a light permeable dielectric layer formed on the piezoelectric element, at least a part of the IDT electrode, and the reflection film. Accordingly, when measuring the film thickness of the light permeable dielectric layer by light interference method, the reflected light from the reflection film having a higher reflectivity than the reflectivity of the piezoelectric element in a visible light wavelength region can be utilized, so that the film thickness can be measured more accurately.