Murata Manufacturing Co., Ltd.

Chihiro Konoma

Ryo Nakagawa

Masashi Tsubokawa

Taku Kikuchi

In an elastic wave device, an IDT electrode is disposed on a piezoelectric substrate and includes a close contact layer, which includes first and second main surfaces and side surfaces. The first main surface is in contact with the piezoelectric substrate, and at least two electrode layers are disposed on the close contact layer. The at least two electrode layers include a first electrode layer and a second electrode layer. The first electrode layer is made of a material that has a higher density than that of Al. The second electrode layer has a lower density than the first electrode layer. One of the at least two electrode layers has higher weather resistance than the close contact layer and covers the side surfaces of the close contact layer.

Elastic wave device

An acoustic wave device includes a piezoelectric substrate and an IDT electrode directly or indirectly disposed on the piezoelectric substrate. The IDT electrode includes first metal layers, a second metal layer disposed on one of the first metal layers, and a third metal layer disposed on the second metal layer. The first, second, and third metal layers include side surfaces, respectively. The side surface includes a first end portion adjacent to the second metal layer. The side surface includes a second end portion adjacent to the second metal layer. In at least a portion of the IDT electrode, a creepage distance stretching from the first end portion to the second end portion via the side surface of the second metal layer is longer than a distance between the first end portion and the second end portion.

Acoustic wave device

An elastic wave device includes a piezoelectric substrate and an interdigital transducer electrode provided on the piezoelectric substrate. The interdigital transducer electrode includes at least one electrode layer including an outermost electrode layer, and a protective electrode layer protecting the outermost electrode layer, the protective electrode layer has a higher electric resistivity than the outermost electrode layer, the outermost electrode layer includes a first principal surface located at a side opposite to the piezoelectric substrate side, and a side surface connected to the first principal surface, the first principal surface of the outermost electrode layer and a region extending from the first principal surface to at least a portion of the side surface are covered with the protective electrode layer, and the protective electrode layer does not extend beyond a lower edge of the side surface of the outermost electrode layer.

An acoustic wave device includes a piezoelectric substrate including an electrode formation surface, and an IDT electrode provided on the electrode formation surface. The IDT electrode includes a close contact layer located on the electrode formation surface, and a main electrode layer located on the close contact layer. The close contact layer includes first and second layers that respectively include first and second lateral surfaces. An area of a surface of the second layer that is in close contact with the main electrode layer is smaller than an area of a surface of the first layer that is in close contact with the piezoelectric substrate. An inclination angle of the second lateral surface is smaller than an inclination angle of the first lateral surface.

Acoustic wave device and manufacturing method for same

An elastic wave device includes a substrate including a piezoelectric material layer and an IDT electrode on the piezoelectric material layer. The IDT electrode includes a Pt film, a Ti film on the Pt film, and an Al-based metal film on the Ti film. The Ti film is quasi-single-crystalline.

An elastic wave device includes a piezoelectric substrate including a primary surface and a first electrode which is provided on the primary surface of the piezoelectric substrate, which includes a first multilayer metal film including at least three metal films laminated in a bottom-to-top direction, and which includes at least an IDT film. The first multilayer metal film includes a Ti film as the topmost film and has a crystal orientation oriented in a predetermined direction so that the normal line direction of the plane of a Ti crystal of the Ti film coincides with the Z axis of a crystal of a piezoelectric body defining the piezoelectric substrate.

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Nagaokakyo, Japan

Chihiro Konoma