An elastic wave device includes elastic wave elements, each including a piezoelectric layer directly or indirectly supported by a supporting substrate and an electrode disposed in contact with the piezoelectric layer, and a highly heat-conductive member stacked on a surface of the supporting substrate, opposite to the surface supporting the piezoelectric layer, in which the thermal conductivity of the supporting substrate is higher than the thermal conductivity of the piezoelectric layer, the coefficient of linear expansion of the supporting substrate is lower than the coefficient of linear expansion of the piezoelectric layer, the highly heat-conductive member has a larger area than the surface of the supporting substrate supporting the piezoelectric layer, and the thermal conductivity of the highly heat-conductive member is higher than that of the piezoelectric layer.

A vibrator device includes a circuit element, which has a first terminal and is a quadrangle in plan view, a vibrator, which is disposed on an active surface and is a quadrangle in plan view, a base, on which the circuit element is disposed and which has a second terminal, and a wire which connects the first terminal and the second terminal together. In plan view of the circuit element, at least one side of the vibrator is disposed along a direction where the one side intersects each of two adjacent sides of the circuit element, and the vibrator does not overlap the first terminal.

An elastic wave device including a sealing structure. Examples of the elastic wave device include a piezoelectric substrate, an IDT electrode provided on the substrate, a first wiring electrode provided on the substrate adjacent the IDT electrode, a second wiring electrode provided on the first wiring electrode, and a dielectric sealing structure that extends over and seals an excitation space above the IDT electrode in which the IDT electrode excites the elastic wave. The second wiring electrode includes a protrusion formed on its outer periphery and extending beyond the first wiring electrode into the excitation space. The first and/or second wiring electrodes are electrically connected to the IDT electrode. The dielectric sealing structure includes a sealing wall provided on the second wiring electrode, the sealing wall being spaced apart from the IDT electrode by the protrusion and having a side surface that defines a side edge of the excitation space.

A SAW filter includes a substrate, an upper bus bar arranged on the substrate, a lower bus bar arranged on the substrate so as to face the upper bus bar, a first finger IDT arranged so as to be connected to the upper bus bar at one end, a second finger IDT arranged so as to be connected to the lower bus bar at one end, a passivation part formed on the first finger IDT and the second finger IDT, a first metal part formed on the passivation part and including all area of the upper bus bar and a partial area of the first finger IDT, and a second metal part formed on the passivation part and including all area of the lower bus bar and a partial area of the second finger IDT.

A microacoustic component includes a functional acoustic region, an inner marginal region and an outer marginal region. The cover covers the functional acoustic region and has a thin film and a bearing surface. The inner marginal region is acoustically coupled to the functional acoustic region and the bearing surface bears directly at least on a part of the inner marginal region.

An acoustic wave element includes IDT electrodes on two main surfaces of a piezoelectric layer, and reflectors on both of the two main surfaces. The IDT electrodes each include electrode fingers extending in a second direction that intersects a first direction. The reflectors each include reflection electrode fingers extending in the second direction. An array pitch of the electrode fingers along the first direction is Pi, an array pitch of the reflection electrode fingers is Pr, and an IDT-reflector gap in the first direction d1 between a center of an electrode finger and a center of a reflection electrode finger that is closest to the IDT electrode among the plurality of reflection electrode fingers is G, a thickness of the piezoelectric layer is smaller than or equal to twice Pi, G is smaller than Pr, and Pr is greater than Pi.

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 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.

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.

A protection film for a surface acoustic wave element, the protection film being configured to prevent moisture absorption into a silicon dioxide film to improve the moisture resistance capability and configured to be unsusceptible to oxidation and stable such that the propagation characteristics of the surface acoustic wave are not adversely affected. The surface acoustic wave element includes a piezoelectric substrate having a top surface, an IDT electrode formed on the top surface of the piezoelectric substrate and including a plurality of electrode fingers configured to excite a surface acoustic wave, a first silicon dioxide film formed to cover the comb-shaped electrode on the top surface of the piezoelectric substrate, a silicon oxynitride film formed over and in contact with the first silicon dioxide film, and a second silicon dioxide film formed over and in contact with the silicon oxynitride film.