A sensor assembly includes a die substrate and a metalized layer formed on the die substrate. The metalized layer is formed of a first metal material and includes a bonding pad to facilitate electrically coupling the sensor assembly to a sensor system. A re-metalized bump is formed on the bonding pad of a second metal material and is electrically coupled to the metalized layer. An adhesive is applied to the re-metalized bump and facilitates mechanically coupling the sensor assembly to the sensor system.

A method for manufacturing a substrate for a radiofrequency filter by joining a piezoelectric layer to a carrier substrate via an electrically insulating layer, wherein the method comprises depositing the electrically insulating layer by spin coating an oxide belonging to the family of SOGs (spin-on glasses) on the surface of the piezoelectric layer to be joined to the carrier substrate, followed by an anneal for densifying the electrically insulating layer before joining the piezoelectric layer to the carrier substrate via the electrically insulating layer.

[Object] It is an object of the present invention to provide a lithium tantalate single crystal substrate which undergoes only small warpage, is free from cracks and scratches, has better temperature non-dependence characteristics and a larger electromechanical coupling coefficient than a conventional Y-cut LiTaO.sub.3 substrate. [Means to solve the Problems] The lithium tantalate single crystal substrate of the present invention is a rotated Y-cut LiTaO.sub.3 single crystal substrate having a crystal orientation of 36° Y-49° Y cut characterized in that: the substrate is diffused with Li from its surface into its depth such that it has a Li concentration profile showing a difference in the Li concentration between the substrate surface and the depth of the substrate; and the substrate is treated with single polarization treatment so that the Li concentration is substantially uniform from the substrate surface to a depth which is equivalent to 5-15 times the wavelength of either a surface acoustic wave or a leaky surface acoustic wave propagating in the LiTaO.sub.3 substrate surface.

A vibration detection element (10) includes substrates (1 to 3), a support member (22), a support member (32), and an oscillator (4). The substrates (1 to 3) have a space portion (SP) having a bottom surface (21A) and a bottom surface (31A) opposed to the bottom surface (21A). The support member (22) protrudes from the bottom surface (21A) toward the bottom surface (31A) of the space portion (SP). The support member (32) protrudes from the bottom surface (31A) toward the bottom surface (21A) of the space portion. The oscillator (4) is disposed in contact with the support member (22) or the support member (32) and capable of vibrating in the space portion (SP) and has a thickness less than 10 μm. The support members (22, 32) each include multiple supports which prevent the oscillator (4) from contacting the bottom surface (21A) or the bottom surface (31A).

A piezoceramic ultrasonic transducer for a vehicle includes: a disc-shaped piezoceramic oscillator configured to generate ultrasonic waves; a printed circuit board configured to provide electric power to the disc-shaped piezoceramic oscillator; and a composite elastomeric element arranged between the disc-shaped piezoceramic oscillator and the printed circuit board, the composite elastomeric element being configured to support the piezoceramic oscillator on the printed circuit board. The composite elastomeric element includes a first elastomeric compound element and a second elastomeric compound element. The first elastomeric compound element includes a first temperature dependent viscoelasticity and supports the piezoceramic oscillator on the printed circuit board in a first temperature range and the second elastomeric compound element includes a second temperature dependent viscoelasticity and supports the piezoceramic oscillator on the printed circuit board in a second temperature range different from the first temperature range.

The present disclosure provides methods to integrate piezoelectric micromachined ultrasonic transducer (pMUT) arrays with an application-specific integrated circuit (ASIC) using thermocompression or eutectic/solder bonding. In an aspect, the present disclosure provides a device comprising a first substrate and a second substrate, the first substrate comprising a pMUT array and the second substrate comprising an electrical circuit, wherein the first substrate and the second substrate are bonded together using thermocompression, wherein any set of individual PMUTs of PMUT array is addressable. In another aspect, the present disclosure provides a device comprising a first substrate and a second substrate, the first substrate comprising a pMUT array and the second substrate comprising an electrical circuit, wherein the first substrate and the second substrate are bonded together using eutectic or solder bonding, wherein any set of individual PMUTs of the PMUT array is addressable.

The present invention relates to a heterostructure, in particular, a piezoelectric structure, comprising a cover layer, in particular, a layer of piezoelectric material, the material of the cover layer having a first coefficient of thermal expansion, assembled to a support substrate, the support substrate having a second coefficient of thermal expansion substantially different from the first coefficient of thermal expansion, at an interface wherein the cover layer comprises at least a recess extending from the interface into the cover layer, and its method of fabrication.

A hybrid structure for a surface acoustic wave device comprises a working layer of piezoelectric material assembled with a support substrate having a lower coefficient of thermal expansion than that of the working layer, and an intermediate layer located between the working layer and the support substrate. The intermediate layer is a sintered composite layer formed from powders of at least a first material and a second material different from the first.

A process for fabricating a substrate for a radiofrequency device by joining a piezoelectric layer to a carrier substrate by way of an electrically insulating layer, the piezoelectric layer having a rough surface at its interface with the electrically insulating layer, the process being characterized in that it comprises the following steps: providing a piezoelectric substrate having a rough surface for reflecting a radiofrequency wave, depositing a dielectric layer on the rough surface of the piezoelectric substrate, providing a carrier substrate, depositing a photo-polymerizable adhesive layer on the carrier substrate, bonding the piezoelectric substrate to the carrier substrate by way of the dielectric layer and of the adhesive layer, in order to form an assembled substrate, irradiating the assembled substrate with a light flux in order to polymerize the adhesive layer, the adhesive layer and the dielectric layer together forming the electrically insulating layer.

A bonding layer 3 is formed over a piezoelectric material substrate, and the bonding layer is made of one or more materials selected from the group consisting of silicon nitride, aluminum nitride, alumina, tantalum pentoxide, mullite, niobium pentoxide and titanium oxide. A neutralized beam is irradiated onto a surface of the bonding layer and a surface of a supporting body to activate the surface of the bonding layer and the surface of the supporting body. The surface of the bonding layer and the surface of the supporting body are bonded by direct bonding.