Murata Manufacturing Co., Ltd.

Daisuke Tamazaki

Katsuya Daimon

Masakazu Mimura

Takeshi Nakao

Toshimaro Yoneda

Yasumasa Taniguchi

Masato Araki

An elastic wave device includes a piezoelectric substrate made of LiNbO, interdigital transducer electrodes on the piezoelectric substrate, and a first dielectric film provided on the piezoelectric substrate and the first dielectric film to cover the IDT electrodes and made of a silicon oxide. The IDT electrodes include a first metal film made of one metal selected from Pt, Cu, Mo, Au, W, and Ta. The Euler angles (&#x3d5;, &#x3b8;, &#x3c8;) of the piezoelectric substrate are (0&#xb1;5&#xb0;, &#x2212;90&#xb0;&#x2264;&#x3b8;&#x2264;&#x2212;70&#xb0;, 0&#xb0;&#xb1;5&#xb0;). The metal for the first metal film and the thickness hm/&#x3bb; (%) match any of the combinations as follows: 

Elastic wave device

An elastic wave device includes first mass adding films provided on a first dielectric film to overlap with first and second electrodes fingers of an IDT electrode when seen from above, extend in a direction in which the first and second electrode fingers extend, and are provided in a center region, and second and third mass adding films that are provided on the first dielectric film and are provided in first and second edge regions, respectively, and a portion of which overlap with at least one of the first and second electrode fingers when seen from above. Dimensions of the second and third mass adding films along an elastic wave propagation direction are larger than a dimension of the first mass adding films along the elastic wave propagation direction.

An elastic wave device includes a piezoelectric substrate, a first dielectric film disposed on the piezoelectric substrate, and an IDT electrode laminated on the first dielectric film. The resistivity of the piezoelectric substrate is equal to or lower than the resistivity of the first dielectric film. The resistivity of the first dielectric film is equal to or lower than about 1&#xd7;10&#x3a9;&#xb7;cm.

In an elastic wave device, an interdigital transducer (IDT) electrode is disposed on a piezoelectric substrate. In at least one of first and second electrode fingers of the IDT electrode, elongated sections with a widthwise dimension larger than that of a center of the first and second electrode fingers in a longitudinal direction are provided in at least one of a portion closer to a base end of the first or second electrode finger and a portion closer to a leading end of the first or second electrode finger than a central region of the first or second electrode finger. At least one of first and second busbars includes a plurality of openings provided separately from each other along the longitudinal direction of the first and second busbars.

Elastic wave device including electrode fingers with elongated sections

A surface acoustic wave device has first and second surface acoustic wave filter elements which are arranged on a surface acoustic wave substrate so as to define a filter device having a two-stage configuration. A free surface portion is provided by forming a perforation in an inter-stage connecting portion connecting the first and second surface acoustic wave filter elements.

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Nagaokakyo, Japan

Daisuke Tamazaki