Murata Manufacturing Co., Ltd.

Yuta Ishii

Tetsuya Kimura

Takashi Yamane

Sho Nagatomo

Kazunori Inoue

Naohiro Nodake

Akihiro Iyama

An acoustic wave device includes a piezoelectric film and an IDT electrode on the piezoelectric film. The IDT electrode includes first and second busbars, at least one first electrode finger, and at least one second electrode finger. When an overlap region is defined as a region in which the first and second electrode fingers overlap each other in an acoustic wave propagation direction, points A, B, C, and D, defined as follows, are all outside the cavity when, at the points A, B, C, and D, xa>about 25 μm, ya>about 25 μm, xb>about 25 μm, yb>about 25 μm, xc>about 25 μm, yc>about 25 μm, xd>about 25 μm, and yd>about 25 μm.

Acoustic wave device

An acoustic wave device includes a support substrate, a piezoelectric layer, a functional electrode, a first trace, a second trace, and an attenuation layer. The piezoelectric layer is located on the support substrate and includes first and second main surfaces on opposite sides. The functional electrode is located on the first or second main surface of the piezoelectric layer. The first trace is located on the piezoelectric layer and connected to the functional electrode. The second trace is located on the piezoelectric layer and faces the first trace. The first and second traces are connected to different potentials. The attenuation layer is located between the first trace and the second trace when viewed in plan. The attenuation layer is made of a dielectric material lower in density than the piezoelectric layer.

An acoustic wave device includes a support substrate, a piezoelectric layer on the support substrate, functional electrodes on the piezoelectric layer, and first and second electrode films positioned on the piezoelectric layer to face each other and having different potentials from each other. A thickness of the piezoelectric layer in at least a portion of a first region overlapping the first electrode film in plan view is different from a thickness of the piezoelectric layer in at least a portion of a second region not overlapping the first electrode film in plan view.

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Nagaokakyo, Japan

Yuta Ishii