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:
Jun. 21, 2005
Filed:
Oct. 23, 2001
Ryoichi Takayama, Osaka, JP;
Hidekazu Nakanishi, Osaka, JP;
Tetsuo Kawasaki, Osaka, JP;
Toru Sakuragawa, Osaka, JP;
Yasuhiko Yokota, Osaka, JP;
Ryoichi Takayama, Osaka, JP;
Hidekazu Nakanishi, Osaka, JP;
Tetsuo Kawasaki, Osaka, JP;
Toru Sakuragawa, Osaka, JP;
Yasuhiko Yokota, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a surface acoustic wave (SAW) filter including a substrate and an electrode formed on the substrate, the electrode includes a base layer, a first metal layer made of a metal consisting of Al or consisting mainly of Al, and having a given orientation relative to the substrate, a second layer for preventing the first metal layer from migration of Al atoms occurring in vertical to the substrate, and a third layer for adjusting a thickness of the layer. In this SAW filter having an arbitrary layer thickness, the layer hardly causes grain boundary diffusion, and grains of the layer can be made fine for effective resistance to stress. Thus, in this SAW filter, the migration of the Al atoms of the electrode that is associated with the SAW propagation-induced stress imposed on the electrode is inhibited. Accordingly, the filter exhibits excellent resistance against electric power.