Murata Manufacturing Co., Ltd.

Daisuke Ajima

Seiji Kai

Masaru Yata

Takao Mukai

Takuya Koyanagi

An acoustic wave device includes a piezoelectric substrate, an interdigital transducer electrode on the piezoelectric substrate, and reflectors. The interdigital transducer electrode includes first and second busbars including first and second cavities in a first direction, and first and second edge regions and first and second gap regions. The first and second edge regions include low acoustic velocity regions. Regions in which the first and second cavities are provided include high acoustic velocity regions. The reflector includes first and second reflector busbars and first reflection electrode fingers each including a second end portion that faces the second reflector busbar. The first reflection electrode fingers overlap the entire or substantially the entire second gap region when viewed in the first direction.

Acoustic wave device

A ladder filter includes a piezoelectric substrate, an antenna terminal, a transmission terminal, and ground terminals on the piezoelectric substrate, and IDT electrodes. Each of the IDT electrodes is disposed on the piezoelectric substrate and includes a plurality of electrode fingers and a pair of busbars to which first ends of the plurality of electrode fingers are connected commonly. The IDT electrodes define elastic wave resonators. The ladder filter further includes an interlayer insulating film disposed on at least one of the busbars and a thermally conductive member made of a material with thermal conductivity higher than that of the interlayer insulating film and disposed on the interlayer insulating film. The thermally conductive member is in contact with at least one of the antenna terminal, the transmission terminal, and the ground terminals.

Ladder filter

In a surface acoustic wave device, a conductor pattern is located on a main surface of a piezoelectric substrate and includes a surface acoustic wave element pattern, a pad and a feed line that is electrically connected to the pad and extends up to an outer peripheral edge of the main surface. The piezoelectric substrate and a cover are bonded to each other with a support layer therebetween that includes a frame extending along the outer peripheral edge of the main surface so that a gap is provided between the frame and the outer peripheral edge and includes a pad adjacent portion on the pad. Thus, a closed space is surrounded by the piezoelectric substrate, the cover and the frame. The support layer further includes a reinforcement portion that intersects a feed line at or near an intersection portion in which a separated portion of the frame that is separated from the pad adjacent portion intersects the feed line.

Surface acoustic wave device and manufacturing method therefor

An elastic wave apparatus includes a piezoelectric substrate including a main surface and a polarization axis direction having a tilt angle with respect to the main surface, an IDT electrode provided on the main surface, and at least one line on the main surface and between an end edge of the main surface and the IDT electrode. A relationship a&#x2264;316|cos(&#x3b8;)|&#x3bc;m is satisfied where a denotes a distance from the end edge of the main surface to the IDT electrode and b&#x2265;28 &#x3bc;m where a dimension of the line along a direction connecting the end edge to the IDT electrode is defined as a width, b denotes the width of the line when one line is provided, and b denotes the sum of the widths of multiple lines when the multiple lines are provided.

Elastic wave apparatus

A longitudinally-coupled resonator-type acoustic wave device includes first to third IDT electrodes disposed on a piezoelectric material and first and second reflectors disposed in acoustic wave propagation directions. Each of any two IDT electrodes adjacent to each other in the acoustic wave propagation directions, of the first to third IDT electrodes, has a narrower-pitch electrode finger portion at an edge thereof adjacent to the other IDT electrode. Most portions of the first to third IDT electrodes are apodized, and the narrower-pitch electrode finger portions and the electrode finger portions adjacent thereto are normally shaped.

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Nagaokakyo, Japan

Daisuke Ajima