A piezoelectric device includes a base member, a first conductive film arranged above the base member in contact with an upper surface of the base member, a piezoelectric film arranged above the first conductive film in contact with an upper surface of the first conductive film, a second conductive film arranged on the piezoelectric film, and an insulating portion provided inside a trench penetrating through the piezoelectric film and the first conductive film. The insulating portion has a higher electrical resistivity than the piezoelectric film.

A structure of an integrated crystal oscillator package has a first quartz crystal resonator, a second quartz crystal resonator, and application-specific integrated circuit chip (ASIC) combined in a package. The ASIC has a switch control for receiving audio formats of 44.1 kHz and 48 kHz with different hi-fidelity (hi-fi). The first quartz crystal resonator has a first clock rate corresponding to the 44.1 kHz frequency and the second quartz crystal resonator has a second clock rate corresponding to the 48 kHz frequency to be switched by the present invention in operation.

The invention relates to a piezoceramic sensor in a housing having a layer (3), preferably a PZT layer, made of a piezoelectric material, on both sides of which there is a respective sensor electrode (2), both sensor electrodes (2) being connected in each case to a pole (5, 6). In order that no potential difference, which would allow for the charge to be dissipated by way of the surface, is formed between the housing and the sensor electrodes (2), it is proposed according to the invention that the layer (3) protrudes beyond the sensor electrode (2) on at least one side of the layer (3), and a protective electrode (1) which encompasses the sensor electrode (2) at an insulating distance (7) is arranged on that part of the layer (3) which protrudes beyond the sensor electrode (2).

A package that includes a first filter comprising a first polymer, a substrate cap, a second filter comprising a second polymer frame, at least one interconnect, an encapsulation layer and a plurality of through encapsulation vias. The substrate cap is coupled to the first polymer frame such that a first void is formed between the substrate cap and the first filter. The second polymer frame is coupled to the substrate cap such that a second void is formed between the substrate cap and the second filter. The at least one interconnect is coupled to the first filter and the second filter. The encapsulation layer encapsulates the first filter, the substrate cap, the second filter, and the at least one interconnect. The plurality of through encapsulation vias coupled to the first filter.

A vibration device includes a substrate having a first surface and a second surface at an opposite side to the first surface, a vibration element disposed on the first surface, a first through electrode which penetrates the substrate, and is configured to electrically couple the power supply interconnection disposed on the second surface and the first circuit block disposed on the first surface, and a second through electrode which penetrates the substrate, and is configured to electrically couple the power supply interconnection and the second circuit block including an analog circuit disposed on the first circuit, wherein R1>R4 and R2>R4, in which R1 is an electric resistance of the first through electrode, R2 is an electric resistance of the second through electrode, and R4 is an electric resistance of a zone of the power supply interconnection coupling the first through electrode and the second through electrode.

A piezoelectric element includes a laminate including first and second piezoelectric layers with respective polarization directions in a thickness direction and an elastic layer provided between the first piezoelectric layer and the second piezoelectric layer, first and second terminal electrodes that are provided on an external surface of the laminate, a first detection electrode provided on a positive polar surface of the first piezoelectric layer, a second detection electrode provided on a negative polar surface of the first piezoelectric layer, a third detection electrode provided on a positive polar surface of the second piezoelectric layer, and a fourth detection electrode provided on a negative polar surface of the second piezoelectric layer. The first detection electrode and the fourth detection electrode are connected to the first terminal electrode. The second detection electrode and the third detection electrode are connected to the second terminal electrode.

An elastic wave device in which an IDT electrode defines an excitation electrode on a piezoelectric layer, an acoustic reflection layer is laminated on a first main surface of the piezoelectric layer, the acoustic reflection layer includes high acoustic impedance layers with a relatively high acoustic impedance and low acoustic impedance layers with a relatively low acoustic impedance, and the acoustic reflection layer has an unwanted wave reflection suppression structure in which reflection of unwanted waves toward the piezoelectric layer side is significantly reduced or prevented.

A fingerprint sensor device includes a sensor substrate, a plurality of sensor circuits over a first surface of the sensor substrate, and a transceiver layer located over the plurality of sensor circuits and the first surface of the sensor substrate. The transceiver layer includes a piezoelectric layer and a transceiver electrode positioned over the piezoelectric layer. The piezoelectric layer and the transceiver electrode are configured to generate one or more ultrasonic waves or to receive one or more ultrasonic waves. The fingerprint sensor device may include a cap coupled to the sensor substrate and a cavity formed between the cap and the sensor substrate. The cavity and the sensor substrate may form an acoustic barrier.

The ultrasound probe includes a piezoelectric element including a piezoelectric composition and an electrode that applies a voltage to the piezoelectric composition. The piezoelectric composition has piezoelectric characteristics expressed by any coordinates included in a region formed by a polyhedron having a plurality of predetermined points as vertexes in Cartesian coordinates (k.sub.eff, ε.sub.33.sup.S, E.sub.c) including variables k.sub.eff, ε.sub.33.sup.S and E.sub.c.

An ultrasound-on-a-chip device has an ultrasonic transducer substrate with plurality of transducer cells, and an electrical substrate. For each transducer cell, one or more conductive bond connections are disposed between the ultrasonic transducer substrate and the electrical substrate. Examples of electrical substrates include CMOS chips, integrated circuits including analog circuits, interposers and printed circuit boards.