Abstract: A structure with superior shock resistance is proposed for a parasol-type acceleration sensor. The acceleration sensor comprises a support portion the lower end of which is fixed to a substrate; a beam portion on which a detection element for applying changes to an output signal in correspondence with strain caused by acceleration acting on the detection element is formed, one end of the beam portion being connected to the top part of the support portion; a suspended weight connected to the other end of the beam portion; and a stopper substrate with a window portion through which, in order to guide an output signal of the detection element via a pad that is formed on the upper end face of the support portion, a conductor lead that is connected to the pad passes. Overswing of the weight is limited by means of the stopper substrate.

Abstract: A surface acoustic wave (SAW) filter includes a piezoelectric substrate, a first interdigital transducer (IDT) for input and a second IDT for output that are provided on the piezoelectric substrate, the first IDT and the second IDT being arranged in a propagation direction, and a shield electrode arranged between the first IDT and the second IDT and/or between interconnection lines that connect the first IDT and the second IDT, at least one of the first IDT and the second IDT being of a longitudinal coupling multi-mode type having a balanced operation. Thus, it is possible to suppress a stray capacitance between the first IDT and the second IDT, and thereby to improve the symmetry of balanced operation signals.

Abstract: A package substrate includes signal pads provided on a main surface of the package substrate, footpads provided on a backside of the package substrate, and a sealing electrode provided on the main surface to surround the signal pads, the signal pads being electrically coupled to the footpads, the sealing electrode being insulated from the footpads.

Abstract: An antenna duplexer includes two surface acoustic wave filters having different center frequencies and a phase matching circuit that matches phases of the two surface acoustic wave filters. A matching line pattern is provided on at least two layers between the two surface acoustic wave filters and transmission and reception terminals, and within an area specified by a sheet-like ground in a multilayered package, the multilayered package comprising multiple layers including a bonding layer on which wire bonding pads are provided for connecting to the two surface acoustic wave filters, and the matching line pattern having no portion provided on bonding layer.

Abstract: A surface acoustic wave device includes, a first substrate, a surface acoustic wave chip attached to the first substrate, and a second substrate that hermetically seals the surface acoustic wave chip. At least one of the first and second substrates includes. The first and second substrates have respective joining surfaces. An electric circuit is formed on a surface area of the first substrate other than the joining surfaces.

Abstract: A filter element includes resonators that are arranged in series arms and parallel arms in a circuit. In this filter element, at least one of the series-arm resonators includes a plurality of single-terminal pair piezoelectric thin-film resonators connected in parallel.

Abstract: Disclosed is a method of manufacturing a surface acoustic wave device comprising the steps of forming a drive electrode having a surface acoustic wave element function on a piezoelectric substrate wafer, providing a resist coat on an upper region of the drive electrode, covering the resist coat with a metal film, removing the resist coat lying within the metal film so that the metal film is formed in a dome form having a hollow portion covering the drive electrode, and providing a resin seal on the metal film.

Abstract: A detector is made up of a semiconductor integrated circuit in a part, and the semiconductor integrated circuit includes a driving circuit, an AC amplifier, a detection circuit and an amplifier circuit. An input resistor that is connected to input terminals of an operational amplifier includes an internal input resistor made up of a semiconductor integrated circuit element and an external input resistor made up of an external discrete component connected to each other in parallel. Temperature characteristics of an angular velocity sensor is compensated by a temperature coefficient (a3) that is a combination of a temperature coefficient (al) of the internal input resistor and a temperature coefficient (a2) of the external input resistor.

Abstract: A microstructure, suitable for avoiding sticking phenomena, includes a base, a first structural portion joined to the base, and a second structural portion opposed to the base and having a fixed end fixed to the first structural portion. Such a microstructure is made by a method including the step of processing a material substrate having a stacked structure made of a first layer, a second layer, and an intermediate layer between the first and second layers. By this method, the first layer is formed with the first structural portion, the second structural portion having the fixed end fixed to the first structural portion, and a support beam bridging the first and second structural portions. Thereafter, wet etching is performed to remove a region of the intermediate layer between the second layer and the second structural portion, followed by a drying step, and a cutting step with respect to the support beam.

Abstract: A sensor stem supporting a sensor element comprising a metal plate having a shape defined by press, the metal plate include a dent portion formed on a first surface of the metal plate, a step portion formed on a second surface of the metal plate facing the first surface, and a projection formed on the step portion for resistance welding. It is thus possible to obtain an excellent hermetic sealing of the sensor stem and a cap, which protects an oscillator, a circuit board and the like. The sensor stem can prevent a short circuit and can be lowered in height thereof.

Abstract: A surface acoustic wave device that enables to reduce heating process, prevent from heat break, and make thin profile is to be provided. The surface acoustic wave device includes a substrate, a surface acoustic wave element having a comb electrode formed on a piezoelectric substrate, and being flip-mounted on the substrate using a bump in such a manner as the comb electrode is disposed opposite to the substrate, a first resin layer covering the surface acoustic wave element, and a second resin layer formed on the first resin layer, wherein the first resin layer and the second resin layer are thermosetting resins in which state transitions of being softened and thereafter cured are produced through heating process, and the first resin layer is formed of a resin material having greater fluidity caused by softening than the resin material of the second resin layer.

Abstract: A surface acoustic wave filter capable of obtaining a low insertion loss and wide bandwidth characteristic is provided. The surface acoustic wave filter includes a piezoelectric substrate; a pair of reflective electrodes formed on the piezoelectric substrate; and a plurality of comb electrodes formed between the pair of reflective electrodes on the piezoelectric substrate, wherein, in regard to the neighboring two comb electrodes among the plurality of comb electrodes, an electrode pitch of one comb electrode is set so that continuously varying phases of surface acoustic waves respectively generated by the two comb electrodes are obtained in a gap opposite to an outermost finger electrode of the other neighboring comb electrode.

Abstract: A balanced filter includes a package having an input ground metal pattern and an output ground metal pattern, and a filter chip having an inphase filter and an antiphase filter, which filters are mounted on the package, at least one of the inphase and antiphase filters having an input ground terminal connected to the input ground metal pattern and an output ground terminal connected to the output ground metal pattern, the input and output ground terminals of said at least one of the inphase and antiphase filters being separate from each other on the filter chip.

Abstract: A surface acoustic wave device includes a piezoelectric substrate having a first surface on which comb-like electrodes, first pads connected thereto, and a first film are provided. The first film is located so as to surround the comb-like electrodes. A base substrate has a second surface on which second pads joined to the first pads and a second film joined to the first film are provided. The first and second films joined by a surface activation process define a cavity in which the comb-like electrodes and the first and second pads are hermetically sealed.

Abstract: An elastic boundary wave device includes a first piezoelectric substrate, IDTs arranged thereon, a first dielectric film having a smoothed surface that covers the IDTs, a second substrate that is a silicon-based substrate, and a second dielectric film provided on a main surface of the second substrate. The smoothed surface of the first dielectric surface and a surface of the second dielectric film are joined together.

Abstract: A surface acoustic wave device includes a piezoelectric substrate, a first and a second interdigital transducers (IDTs) provided on the piezoelectric substrate. The first IDT includes multiple tracks having different frequency characteristics that are connected in parallel. The second IDT includes a normalized electrode pattern. The frequency characteristic of the multiple tracks is asymmetric to a center frequency of the SAW filter, substantially flat in a passband when those of the multiple tracks are overlapped, or complementary in the passband. Thus, it is possible to provide the surface acoustic wave device having a high damping property.

Abstract: A surface acoustic wave element includes: metal patterns that include interdigital transducers, each of the metal patterns being formed with a first alloy or multi-layer film of metals having different standard electrode potentials; and metal films each formed with a second alloy or multi-layer film containing metals having different standard electrode potentials from the standard electrode potentials of the metals forming the first alloy or multi-layer film, the metal films being formed at least on a part of the regions other than the regions corresponding to the electrode fingers of the interdigital transducers of all the metal patterns that are electrically independent of one another.

Abstract: A surface acoustic wave (SAW) device includes a SAW chip including comb-like electrodes arranged on a piezoelectric substrate, and a package on which the SAW chip is flip-chip mounted, the package including an interconnection that connects the comb-like electrodes. Resonators are connected to signal interconnection pads through the interconnection pattern. IDTs in a three-IDT multimode filter are respectively connected to the signal interconnection pads via another interconnection pattern. The signal interconnection pads are connected to a signal interconnection provided on a chip mounting surface with bumps. Then, a part of the interconnection pattern connecting the resonators is extracted onto the package. It is thus possible to design the interconnections on the package flexibly and thereby easy to adjust the impedance of the interconnections that connect the resonators.

Abstract: A surface acoustic wave device includes a surface acoustic wave chip having a piezoelectric substrate on which comb-like electrodes and electrode pads are formed, a package housing the surface acoustic wave chip, and electrode patterns provided on a bottom surface of the package. The bottom surface of the package is wider than a top surface of the package. The electrode patterns are away from edges of the bottom surface of the package.

Abstract: A surface acoustic wave device having a given impedance includes multimode type filters connected in series. A composite impedance of the multimode type filters defines the given impedance of the surface acoustic wave device.