A method of manufacturing an acoustic wave device is disclosed. The method includes attaching a support layer to a ceramic layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The method also includes bonding a piezoelectric layer to a surface of the ceramic layer. The method further includes forming an interdigital transducer electrode over the piezoelectric layer.

Certain aspects of the present disclosure provide an electroacoustic device and methods for signal processing via the electroacoustic device. One example electroacoustic device generally includes a first surface acoustic wave (SAW) resonator comprising a first apodized interdigital transducer (IDT) disposed between a first busbar and a second busbar, and a second SAW resonator comprising a second apodized IDT disposed between the second busbar and a third busbar, wherein the second busbar is at an angle with respect to at least one of the first busbar or the third busbar.

An acoustic wave device includes a piezoelectric substrate, and an IDT electrode on the piezoelectric substrate, and the IDT electrode includes an intersection region in which first and second electrode fingers overlap each other in an acoustic wave propagation direction, the intersection region includes a central region and first and second low acoustic velocity regions outside the central region on respective sides in an extending direction of the first and second electrode fingers, first and second busbars include first and second cavities, respectively, first and second inner busbar portions on one side of the first and second cavities, and first and second outer busbar portions on another side are connected by first and second connecting portions, and at least one of the first connecting portions and at least one of the second connecting portions are a first wide width connecting portion and a second wide width connecting portion having a width wider than that of each of remaining first and second connecting portions.

Disclosed in the present disclosure are a surface-acoustic-wave temperature and pressure sensing device and a manufacturing method thereof. The surface-acoustic-wave temperature and pressure sensing device includes a first high-temperature-resistant substrate and a second high-temperature-resistant substrate bonded together, where a recess is formed in the second high-temperature-resistant substrate to form a sealed cavity between the first high-temperature-resistant substrate and the second high-temperature-resistant substrate; first surface-acoustic-wave temperature sensors and surface-acoustic-wave pressure sensors are formed on a first surface of the first high-temperature-resistant substrate located in the cavity, and second surface-acoustic-wave temperature sensors are formed on a second surface of the first high-temperature-resistant substrate opposite the first surface; and the first surface-acoustic-wave temperature sensors, the second surface-acoustic-wave temperature sensors, and the surface-acoustic-wave pressure sensors are electrically connected to one another.

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.

An acoustic wave device includes a plurality of interdigital transducer electrodes, in a first interdigital transducer electrode, a first electrode finger includes a wide portion having a greater width in the second direction than a center portion. In the first interdigital transducer electrode, for the first electrode finger, a first distance that is a maximum distance in the second direction between a center line of the center portion in a first direction is shorter than a second distance that is a maximum distance in a second direction between the center line of the center portion and an outer edge, away from a second interdigital transducer electrode, of the wide portion.

A production method for a surface acoustic wave device comprises the following steps: a step of providing a piezoelectric substrate comprising a transducer arranged on the main front face; a step of depositing a dielectric encapsulation layer on the main front face of the piezoelectric substrate and on the transducer; and a step of assembling the dielectric encapsulation layer with the main front face of a support substrate having a coefficient of thermal expansion less than that of the piezoelectric substrate. In additional embodiments, a surface acoustic wave device comprises a layer of piezoelectric material equipped with a transducer on a main front face, arranged on a substrate support of which the coefficient of thermal expansion is less than that of the piezoelectric material. The transducer is arranged in a dielectric encapsulation layer, between the layer of piezoelectric material and the support substrate.

The invention provides a filter device, an RF front-end device and a wireless communication device. The filter device comprises a substrate, at least one resonance device, a passive device and a connector, wherein the at least one resonance device has a first side and a second side opposite to the first side, the substrate is located on the first side, and the passive device is located on the second side. The at least one resonance device is connected to the passive device through the connector. The RF filter device formed by integrating the resonance device (such as an SAW resonance device or a BAW resonance device) and the passive device (such as an IPD) in one die can broaden the passband width, has a high out-of-band rejection, and occupies less space in an RF front-end chip.

An acoustic wave device fabrication method includes: forming on a piezoelectric substrate a comb-shaped electrode and a wiring layer coupled to the comb-shaped electrode; forming on the piezoelectric substrate a first dielectric film having a film thickness greater than those of the comb-shaped electrode and the wiring layer, covering the comb-shaped electrode and the wiring layer, and being made of silicon oxide doped with an element or undoped silicon oxide; forming on the first dielectric film a second dielectric film having an aperture above the wiring layer; removing the first dielectric film exposed by the aperture of the second dielectric film by wet etching using an etching liquid causing an etching rate of the second dielectric film to be less than that of the first dielectric film so that the first dielectric film is left so as to cover an end face of the wiring layer and the comb-shaped electrode.

Aspects of this disclosure relate to a boundary acoustic wave device. The boundary acoustic wave device can include two low acoustic impedance layers, an interdigital transducer electrode, piezoelectric material positioned between the interdigital transducer electrode and each of the two low acoustic impedance layers, and two high acoustic impedance substrates. The two low acoustic impedance layers can be positioned between the two high acoustic impedance substrates. Related acoustic wave filters, multiplexers, radio frequency modules, wireless communication devices, and methods are disclosed.