Murata Manufacturing Co., Ltd.

Makoto Sawamura

Seiji Kai

Yutaka Kishimoto

Yuzo Kishi

An acoustic wave device includes a piezoelectric substrate including a support substrate and a piezoelectric layer on the support substrate, the piezoelectric substrate including a first principal surface on the piezoelectric layer side, and a second principal surface on the support substrate side, an IDT electrode on the first principal surface, a support layer on the support substrate, a cover on the support layer, a through-via electrode provided through the support substrate and electrically connected to the IDT electrode, a first wiring electrode on the second principal surface of the piezoelectric substrate and electrically connected to the through-via electrode, and a protective film on the second principal surface to cover at least a portion of the first wiring electrode. The protective film is provided on an inner side of the support layer when viewed in a direction normal or substantially normal to the second principal surface.

Acoustic wave device, high-frequency front end circuit, communication device, and method for manufacturing acoustic wave device

An elastic wave device manufacturing method includes a preparing a piezoelectric wafer on which IDT electrodes are provided in elastic wave device forming portions, providing on a first main surface of the piezoelectric wafer support layers in the elastic wave device forming portions, bonding a cover member to cover the support layers to obtain a multilayer body, cutting the multilayer body in a first direction multiple times, cutting the multilayer body in a second direction orthogonal to the first direction to obtain elastic wave devices, in which a resin layer extends across a boundary between the elastic wave device forming portions adjacent to each other on the first main surface of the piezoelectric wafer, and the second cutting step is performed in a state in which the resin layer is present.

Elastic wave device manufacturing method, elastic wave device, radio-frequency front-end circuit, and communication device

An acoustic wave device includes a silicon support substrate that includes first and second main surfaces opposing each other, a piezoelectric structure provided on the first main surface and including the piezoelectric layer, an IDT electrode provided on the piezoelectric layer, a support layer provided on the first main surface of the silicon support substrate and surrounding the piezoelectric layer, a cover layer provided on the support layer, a through-via electrode that extending through the silicon support substrate and the piezoelectric structure, and a first wiring electrode connected to the through-via electrode and electrically connected to the IDT electrode. The piezoelectric structure includes at least one layer having an insulating property, the at least one layer including the piezoelectric layer. The first wiring electrode is provided on the layer having an insulating property in the piezoelectric structure.

Acoustic wave device, high-frequency front-end circuit, and communication device

In an acoustic wave device, a piezoelectric body is directly or indirectly laminated on a silicon support substrate, and a functional electrode is provided on the piezoelectric body. A support layer is directly or indirectly laminated on the silicon support substrate, and the support layer is located outside the functional electrode when viewed in plan view. A silicon cover layer is provided on the support layer that includes an insulating material, and a space A is defined by the silicon support substrate, the support layer, and the silicon cover layer. The electric resistance of the silicon support substrate is higher than the electric resistance of the silicon cover layer.

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Nagaokakyo, Japan

Makoto Sawamura