An acoustic wave element which can be reduced in size and produced relatively easily, practically used without using harmful substances, and can suppress a surface acoustic wave propagation loss, which has an excellent temperature coefficient of frequency and a velocity dispersion characteristic, and with which an increase in the reflection coefficient of interdigital transducers can be suppressed, and a method for manufacturing the acoustic wave element are provided. The acoustic wave element includes a pair of electrodes provided on both surfaces of a piezoelectric substrate, and a dielectric film provided on a first surface of the piezoelectric substrate so as to cover the electrode. The acoustic wave element alternatively includes interdigital transducers provided on a first surface of the piezoelectric substrate, and a dielectric film provided on the interdigital transducers, a gap between the interdigital transducers, and/or a second surface of the piezoelectric substrate.

Embodiments may relate to a die such as an acoustic wave resonator (AWR) die. The die may include a first filter and a second filter in the die body. The die may further include an electromagnetic interference (EMI) structure that surrounds at least one of the filters. Other embodiments may be described or claimed.

A MEMS device may include: (i) a lower cavity, including a first island, formed within a first layer of the MEMS device; (ii) an upper cavity, including a second island, formed within a second layer of the MEMS device; (iii) a MEMS resonating element arranged in a device layer of the MEMS device and anchored via the first and second islands; (iv) a first set of electrodes for electrostatic actuation and sensing of the MEMS resonating element in an in-plane mode that is arranged in the device layer of the MEMS device; and (v) a second set of electrodes for electrostatic actuation and sensing of the MEMS resonating element in an out-of-plane mode that is electrically isolated from the first set of electrodes and located in the first or second layer of the MEMS device, and wherein the out-of-plane mode is a torsional mode or a saddle mode.

A method for manufacturing a ceramic substrate that includes forming a mother multilayer body by positioning a hole in at least one ceramic green sheet among a plurality of laminated ceramic green sheets in a location that does not overlap with a recess formation-planned region in which a recess is to be formed after firing of the mother multilayer body and that overlaps with a singulation-planned line for singulating the mother multilayer body into pieces after firing; and forming the recess in the mother multilayer body before firing by performing press working on the recess formation-planned region of the mother multilayer body.

Provided is a multiplexer that includes a first filter (first transmission filter), a second filter (second reception filter), a third filter (third reception filter), a first inductor, and a second inductor. The first inductor is connected in series with one parallel arm resonator (second parallel arm resonator) of the first filter between the one parallel arm resonator and ground. The second inductor is connected in series with another parallel arm resonator (third parallel arm resonator) of the first filter between the other parallel arm resonator and ground. The first inductor and the second inductor have the same winding direction as each other from the first filter side toward the ground side thereof.

A semiconductor package includes a main substrate, a resonator device disposed above the main substrate, a wiring portion connected to the resonator device, an electrical connection structure connected to the wiring portion and the main substrate, an encapsulant encapsulating the resonator device and the electrical connection structure, and a heat dissipation member bonded to and mounted on the resonator device. A cavity is provided in the resonator device, and is formed between the resonance portion and a resonator device substrate provided in the resonator device.

Aspects of this disclosure relate to a bulk acoustic wave device that includes a multi-layer raised frame structure. The multi-layer raised frame structure includes a first raised frame layer positioned between a first electrode and a second electrode of the bulk acoustic wave device. The first raised frame layer has a lower acoustic impedance than the first electrode. The first raised frame layer and the second raised frame layer overlap in an active region of the bulk acoustic wave device. Related filters, multiplexers, packaged modules, wireless communication devices, and methods are disclosed.

A stacked acoustic wave device assembly is disclosed. The stacked acoustic wave device assembly can include a first acoustic wave device including a first solid acoustic mirror on a first substrate, a first piezoelectric layer on the first solid acoustic mirror and a first interdigital transducer electrode in contact with the first piezoelectric layer. The stacked acoustic wave device assembly can include a second acoustic wave device including a second solid acoustic mirror on a second substrate, a second piezoelectric layer on the second solid acoustic mirror and a second interdigital transducer electrode in contact with the second piezoelectric layer. The stacked acoustic wave device assembly can include a third solid acoustic mirror positioned between the first acoustic wave device and the second acoustic wave device.

An apparatus is disclosed for partially suspending a piezoelectric layer using a dielectric. In an example aspect, the apparatus includes a microacoustic filter with a substrate layer, a piezoelectric layer, an electrode structure that is in contact with the piezoelectric layer, and a dielectric. The electrode structure includes multiple fingers arranged across a plane having a first axis that is perpendicular to the multiple fingers and a second axis that is parallel to the multiple fingers. The dielectric is configured to separate the piezoelectric layer from the substrate layer and define a cavity between the piezoelectric layer and the substrate layer. The dielectric is also configured to support the piezoelectric layer across at least three points along the first axis.

A thin film piezoelectric acoustic wave resonator and a manufacturing method therefor, and a filter. The thin film piezoelectric acoustic wave resonator includes: a first base, an upper electrode, a piezoelectric plate body, a lower electrode and an isolation cavity. The upper electrode, the piezoelectric plate body and the lower electrode are arranged on an upper surface of the first base and are stacked sequentially from top to bottom. The upper electrode, the piezoelectric plate body and the lower electrode have an overlapping region in a direction perpendicular to the surface of the piezoelectric plate body, in which a first gap is formed between the piezoelectric plate body and the upper electrode, and a second gap is formed between the piezoelectric plate body and the lower electrode. The isolation cavity surrounds the periphery of the piezoelectric plate body and connects the first and second gaps together. At least one connecting bridge is arranged between the piezoelectric plate body and the base.