Abstract: An acoustic wave device includes a support substrate with a thickness in a first direction, a piezoelectric layer above or below the support substrate, and a functional electrode on the piezoelectric layer. A space is between the support substrate and the piezoelectric layer to least partially overlap the functional electrode in a plan view in the first direction. At least one through-hole extends through the piezoelectric layer, communicates with the space, and is inside an outer edge of the space in a plan view in the first direction.

Abstract: An acoustic wave device includes a piezoelectric substrate including a support and a piezoelectric layer provided on the support and including first and second main surfaces, one or more functional electrodes provided on the first or second main surface, and including at least one pair of electrodes, a first support provided on the piezoelectric substrate so as to surround the functional electrodes, one or more second supports provided on the piezoelectric substrate and on a portion surrounded by the first support, and a cover on the first support and the second supports. A direction in which adjacent electrodes face each other is an electrode facing direction, a region in which the adjacent electrodes overlap each other when viewed from the electrode facing direction is an intersecting region, and the second support at least partially overlaps the intersecting region when viewed from the electrode facing direction.

Abstract: An acoustic wave device includes a piezoelectric substrate including a support and a piezoelectric layer on the support and including first and second main surfaces, one or more functional electrodes on the first or second main surfaces, and including at least one pair of electrodes, a first support surrounding the functional electrodes, one or more second supports on the piezoelectric substrate and on a portion surrounded by the first support, and a cover on the first and second supports. A direction in which adjacent electrodes face each other is an electrode facing direction, a region in which the adjacent electrodes overlap each other when viewed from the electrode facing direction is an intersecting region, a direction in which at least one pair of electrodes extend is an electrode extending direction, and the second support at least partially overlaps the intersecting region when viewed from the electrode extending direction.

Abstract: An acoustic wave device includes a piezoelectric substrate including a support including a support substrate and a piezoelectric layer on the support and including first and second main surfaces, a functional electrode on the first or second main surface and including a pair of electrodes, a first support on the piezoelectric substrate and surrounding the functional electrode, at least one second support on the piezoelectric substrate in a portion surrounded by the first support, and a lid on the first and second supports. The second support does not overlap an intersecting region when viewed from an electrode extending direction and from an electrode facing direction.

Abstract: An acoustic wave device includes a piezoelectric substrate including a support including a support substrate and a piezoelectric layer on the support, a functional electrode on the piezoelectric layer, at least one support, and a lid. One of the at least one support surrounds the functional electrode on the piezoelectric substrate and the lid is provided on the support. A first cavity is provided in the support. The first cavity overlaps at least a portion of the functional electrode in plan view. A second cavity is surrounded by the piezoelectric substrate, a support provided between the piezoelectric substrate and the lid, and the lid. A height of the first cavity is greater than a height of the second cavity.

Abstract: An acoustic wave device includes a first substrate, a piezoelectric layer adjacent to a first principal surface of the first substrate, a functional electrode on the piezoelectric layer, a second substrate, and a third substrate. The second substrate is adjacent to the first principal surface of the first substrate and faces the first substrate, with a second hollow interposed therebetween. The third substrate is adjacent to a second principal surface of the first substrate and faces the first substrate, with a first hollow interposed therebetween. The acoustic wave device includes a first support portion between the first principal surface of the first substrate and the second substrate, and a second support portion between the first substrate and the third substrate.

Abstract: An acoustic wave device is provided that includes a piezoelectric layer including lithium niobate or lithium tantalate, and a series arm resonator and a parallel arm resonator that each include at least a pair of a first electrode and a second electrode on the piezoelectric layer. The acoustic wave device uses a bulk wave in a first thickness-shear mode. Moreover, a film thickness of a first portion of the piezoelectric layer in the series arm resonator is different from a film thickness of a second portion of the piezoelectric layer in the parallel arm resonator. In each of the series arm resonator and the parallel arm resonator, assuming a film thickness of the piezoelectric layer is d and a distance between centers of the first electrode and the second electrode adjacent to each other is p, a ratio d/p is less than or equal to about 0.5.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An acoustic wave device includes a support including a support substrate, a piezoelectric layer on the support, a functional electrode at the piezoelectric layer, a frame-shaped support frame on the piezoelectric layer and surrounding the functional electrode in a plan view in a stacking direction of the support and the piezoelectric layer, and a lid covering an opening of the support frame, wherein the support includes a first cavity at a position overlapping at least a portion of the functional electrode in the plan view, a second cavity defined by the piezoelectric layer, the support frame, and the lid between the piezoelectric layer and the lid, the piezoelectric layer includes a through hole communicating with the first and second cavities, and the first and second cavities are under vacuum.

Abstract: An acoustic wave device includes a support, a piezoelectric layer on the support, a functional electrode at the piezoelectric layer, a frame-shaped support frame on the piezoelectric layer and surrounding the functional electrode in plan view in a stacking direction of the support and the piezoelectric layer, and a lid covering an opening of the support frame, wherein the support includes a first cavity overlapping at least a portion of the functional electrode in the plan view, a second cavity defined by the piezoelectric layer, the support frame, and the lid between the piezoelectric layer and the lid, the piezoelectric layer includes a through hole communicating with the first and second cavities, and a gas is provided in the first and second cavities.

Abstract: 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.

Abstract: An elastic wave device includes a multilayer film stacked on a support substrate. A first support layer surrounds a region including interdigital transducer electrodes. A second support layer is disposed in the region surrounded by the first support layer. A cover is fixed on the first support layer and the second support layer so as to close a cavity defined by the first support layer. The multilayer film is partially disposed on the support substrate, and an insulating layer is disposed in at least a portion of a region in which the multilayer film is not disposed. At least one of the first support layer and the second support layer is disposed on the insulating layer.

Abstract: An elastic wave device includes a piezoelectric thin film provided on a low acoustic velocity film and an IDT electrode provided on the piezoelectric thin film, wherein the piezoelectric thin film is made of a piezoelectric single crystal and includes a first principal surface that is a positive surface in a polarization axis direction and a second principal surface that is a negative surface in the polarization axis direction. The first principal surface of the piezoelectric thin film faces the low acoustic velocity film, and the second principal surface faces the IDT electrode.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An elastic wave device includes a piezoelectric substrate, functional electrodes on the piezoelectric substrate, a support layer on the piezoelectric substrate with a frame shape surrounding the functional electrodes, a cover member on the support layer to seal an opening of the support layer, the cover member including a first main surface facing the support layer, and a second main surface opposite to the first main surface. Recesses are located in the cover member and are open to the second main surface. Via holes extend through the support layer and to bottom surfaces of the recesses of the cover member, the via holes each including an opening that is open to the bottom surface. The area of the opening of each of the via holes is not more than the area of the bottom surface of the corresponding recess of the cover member. First via conductor portions are provided in the via holes and second via conductor portions are provided in the recesses of the cover member.

Abstract: An elastic wave device includes a lamination layer film including a piezoelectric thin film on a support substrate. The lamination layer film is not partially present in a region located in an outer side portion of a region where IDT electrodes are provided. A first insulation layer extends from at least a portion of a region where the lamination layer film is not present to an upper portion of the piezoelectric thin film. A wiring electrode has a width of about 6 ?m and extends from the upper portion of the piezoelectric thin film to an upper portion of the first insulation layer, and extends onto a section of the first insulation layer in the region.