A crystal oscillator includes an oscillating substrate, a hollow frame, a first electrode, and a second electrode. The oscillating substrate includes a main oscillating region and a thinned region that has a thickness smaller than that of the main oscillating region. The first and second electrodes are disposed on a first surface of the oscillating substrate and a second surface opposite to the first surface, respectively. The hollow frame is disposed on the second surface. The second electrode includes a second electrode portion that has at least one opening in positional correspondence with the thinned region. A method for making the crystal oscillator is also provided herein.

A package comprising an acoustic device, a polymer frame coupled to the acoustic device, a plurality of frame interconnects located in the polymer frame, where the plurality of frame interconnects are coupled to the acoustic device, a polymer cap layer coupled to the acoustic device though the polymer frame, where the polymer cap layer is configured as a cap for the acoustic device, a plurality of cap interconnects located in the polymer cap layer, where the plurality of cap interconnects are coupled to the plurality of frame interconnects, and a cavity located between the acoustic device and the polymer cap layer. The acoustic device includes a substrate and an acoustic element coupled to the substrate.

An apparatus is disclosed for implementing a microacoustic filter with a cavity stack. In an example aspect, the apparatus includes a microacoustic filter with an electrode structure, a cavity stack, a buffer layer, and a piezoelectric layer. The cavity stack comprises a conductive layer, a substrate layer, and at least two pillars extending past a plane defined by a surface of the substrate layer and towards the conductive layer to form a cavity between the substrate layer and the conductive layer. The buffer layer is disposed between the conductive layer of the cavity stack and the electrode structure. The piezoelectric layer is disposed between the buffer layer and the electrode structure.

An acoustic wave filter component can include a surface acoustic wave device including a first piezoelectric layer, an interdigital transducer electrode on the first piezoelectric layer, and an additional layer, such as a temperature compensation layer, over the interdigital transducer electrode. The acoustic wave filter component can also include a bulk acoustic wave resonator supported by the additional layer. The additional layer may be a layer on which a surface acoustic wave of the surface acoustic wave device will propagate. The bulk acoustic wave resonator may include an air cavity, where a shape of the air cavity is defined in part by the additional layer.

A thin film bulk acoustic resonator and a method for manufacturing the same. The thin film bulk acoustic resonator comprises a bottom electrode layer, a piezoelectric layer, and a top electrode layer, which are disposed on a substrate in which an acoustic reflection structure is located, where a portion which is of the piezoelectric layer and corresponds to a boundary of the acoustic reflection structure is depolarized to form a depolarized portion. The method comprises providing a bottom electrode layer on a substrate to cover an acoustic reflection structure which is formed or to be formed on the substrate; providing a piezoelectric layer on the bottom electrode layer; depolarizing a portion, which is of the piezoelectric layer and corresponds to a boundary of the acoustic reflection structure, to form a depolarized portion; and providing a top electrode layer on the piezoelectric layer.

An acoustic wave device includes a supporting substrate, an acoustic reflection film the supporting substrate, a piezoelectric thin film on the acoustic reflection film, and an interdigital transducer electrode the piezoelectric thin film. The acoustic reflection film includes acoustic impedance layers including therein first, second, third, and fourth low acoustic impedance layers and first, second, and third high acoustic impedance layers. The acoustic reflection film includes a first acoustic impedance layer and a second acoustic impedance layer, the first and second acoustic impedance layers each being one of the acoustic impedance layers, and the second acoustic impedance layer has an arithmetic average roughness different from that of the first acoustic impedance layer.

A vibrator element includes: a plate-shaped vibrating substrate including a first surface and a second surface, which are in a front and back relationship, and including a vibrating portion and a support portion that supports the vibrating portion and has a thickness smaller than that of the vibrating portion; an electrode including a first excitation electrode disposed at the first surface at the vibrating portion, a second excitation electrode disposed at the second surface at the vibrating portion, a first pad electrode disposed at the support portion and electrically coupled to the first excitation electrode, and a second pad electrode disposed at the support portion and electrically coupled to the second excitation electrode; a first metal film disposed at an upper layer on the first pad electrode and having a thickness larger than that of the first pad electrode; and a second metal film disposed at an upper layer on the second pad electrode and having a thickness larger than that of the second pad electrode.

A vibrator element includes: a plate-shaped vibrating substrate including a first surface and a second surface, which are in a front and back relationship, and including a vibrating portion, a support portion, and a coupling portion that couples the vibrating portion to the support portion and includes a portion having a thickness smaller than that of the support portion; an electrode layer including a first excitation electrode disposed at the first surface at the vibrating portion, a second excitation electrode disposed at the second surface at the vibrating portion, a first pad electrode disposed at the support portion, a second pad electrode disposed at the support portion, a first coupling electrode disposed at the coupling portion and coupling the first excitation electrode to the first pad electrode, and a second coupling electrode disposed at the coupling portion and coupling the second excitation electrode to the second pad electrode; a first metal film disposed at an upper layer on the first coupling electrode that is located on the coupling portion and having a thickness larger than that of the electrode layer; and a second metal film disposed at an upper layer on the second coupling electrode that is located on the coupling portion and having a thickness larger than that of the electrode layer.

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 clock oscillator, a clock oscillator production method and use method, and a chip including the clock oscillator are provided. The clock oscillator includes a resonator, a shock-absorbing material layer, and a base, and at least a part of the shock-absorbing material layer is located between the resonator and the base. In the clock oscillator, the shock-absorbing material layer is added between the resonator and the base, and the shock-absorbing material layer can effectively prevent a mechanical wave from being conducted between the base and the resonator, so that the resonator is protected from external vibration. This can ensure, when there is external vibration, that an output frequency of the resonator is not deteriorated and improve shock absorption performance of the clock oscillator.