The present disclosure provides a package structure of an air gap type semiconductor device and its fabrication method. The fabrication method includes forming a bonding layer having a first opening on a carrier; disposing a semiconductor chip on the bonding layer, thereby forming a first cavity at the first opening, where the first cavity is at least aligned with a portion of an active region of the semiconductor chip; performing an encapsulation process to encapsulate the semiconductor chip on the carrier; lastly, forming through holes passing through the carrier where each through hole is aligned with a corresponding input/output electrode region of the semiconductor chip, and forming interconnection structures on a side of the carrier different from a side with the bonding layer, where each interconnection structure passes through a corresponding through hole and is electrically connected to an corresponding input/output electrode.

An acoustic wave device includes a piezoelectric substrate, a pair of interleaved interdigital transducer electrodes disposed on the piezoelectric substrate, and a dielectric film including silicon oxynitride covering the pair of interleaved interdigital transducer electrodes. The dielectric film exhibits a temperature coefficient of velocity of substantially zero throughout an operating temperature range of the acoustic wave device of between −55° C. and 125° C.

An electronic filter comprises a high pass section (110) and a low pass section (120). The high pass section includes at least one filter stage of a series-connected acoustic resonator (111) and a parallel connected inductor (114). The low pass section comprises at least one filter stage including a series-connected inductor (121) and a parallel connected acoustic resonator (123). The filter is useful for a communication device covering the n79 5G band.

A surface acoustic wave device includes a piezoelectric substrate and a pair of interdigital transducer electrodes. The pair of interdigital transducer electrodes include an alternating region as a region where the electrode fingers connected to one busbar and the electrode fingers connected to the other busbar are alternately provided. When a region on an end portion side of the alternating region and a region including distal end portions of the plurality of electrode fingers is referred to as an edge region, a propagation velocity of a surface acoustic wave in the edge region is slower than a propagation velocity of a surface acoustic wave in the alternating region. A propagation velocity of a surface acoustic wave in a busbar region as a region where the busbar is disposed is faster than the propagation velocity of the surface acoustic wave in the alternating region.

An acoustic wave device includes: a support substrate; a first piezoelectric substrate bonded to a first principal surface of the support substrate, the first piezoelectric substrate being a single crystal substrate, a first acoustic wave resonator located on an opposite surface of the first piezoelectric substrate from a surface to which the support substrate is bonded, the first acoustic wave resonator including an IDT; a second piezoelectric substrate bonded to a second principal surface of the support substrate opposite from the first principal surface, the second piezoelectric substrate being a single crystal substrate; and a second acoustic wave resonator located on an opposite surface of the second piezoelectric substrate from a surface to which the support substrate is bonded, the second acoustic wave resonator including an IDT.

The invention relates to a device for measuring temperature in a high-voltage portion of a switchgear station, characterised in that it comprises: at least one temperature sensor (21, 22, 23, 24) located at a point on the high-voltage portion of which the temperature is to be monitored, at least one antenna (25) connected to the at least one temperature sensor, a control module (26) located in a low-voltage portion of the switchgear station, and at least one antenna (27) connected to the control module. The at least one temperature sensor (21, 22, 23, 24) is suitable for transmitting a signal representative of a temperature measurement and the control module (26) is suitable for receiving the representative signal, via the antennas, and for processing said signal in order to produce a message.

There is provided a wafer processing method for dividing a wafer having a plurality of devices formed in regions partitioned by a plurality of crossing division lines on a front surface of a substrate having a birefringent crystal structure, into individual device chips. The wafer processing method includes a detection step of detecting the division line formed on the front surface of the wafer by an imaging unit from the back side of the wafer. In the detection step, a polarizer disposed on an optical axis connecting an imaging element and an image forming lens provided in the imaging unit intercepts extraordinary light appearing due to birefringence in the substrate and guides ordinary light to the imaging element.

An elastic wave device propagating plate waves includes a stack of an acoustic reflection layer, a piezoelectric layer, and IDT electrode on a supporting substrate. The piezoelectric layer is thinner than a period of fingers of the IDT electrode. The acoustic reflection layer includes low-acoustic-impedance layers and high-acoustic-impedance layers. The low-acoustic-impedance layers are made of SiO.sub.2, and the high-acoustic-impedance layers are made of at least one material selected from the group consisting of W, LiTaO.sub.3, Al.sub.2O.sub.3, AlN, LiNbO.sub.3, SiN, and ZnO.

An elastic wave device includes an IDT electrode on a piezoelectric substrate, in which the IDT electrode includes first electrode fingers and second electrode fingers, where a portion in which the first electrode fingers and the second electrode fingers overlap with each other in an elastic wave propagation direction is defined as an intersection region including in a direction in which the first and second electrode fingers extend, a center region located on a center side and first and second edge regions respectively located on both sides of the center region, in the first and second edge regions, grooves defining recess portions are provided on the piezoelectric substrate, the first and second electrode fingers are provided inside of the grooves as the recess portions and are disposed on the piezoelectric substrate in the grooves.

An acoustic wave device includes: a piezoelectric substrate that is made of a single crystal piezoelectric material, and includes a first region including an upper surface, and a second region that is located under the first region and has a density less than a density of the first region; and an IDT located on the upper surface of the piezoelectric substrate.