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US 12,689,354 B2Granted
Acoustic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorsKatsuya Daimon, Koji Yamamoto
Life of this patent
Estimating the term…
Abstract
An acoustic wave device includes a piezoelectric substrate and IDT electrodes each including a first pitch portion with a relatively wide electrode finger pitch and a second pitch portion with a relatively narrow electrode finger pitch. A central region is located on a central side in a direction in which electrode fingers extend, and first and second edge regions are located on both sides of the central region. Mass addition films are in the first and second edge regions and include first mass addition films in the first pitch portion and second mass addition films in the second pitch portion. A length of the first mass addition film along an acoustic wave propagation direction is greater than a length of the second mass addition film.
Claims19
An acoustic wave device comprising:
- a piezoelectric substrate;
- and
- a plurality of interdigital transducer (IDT) electrodes extending in an acoustic wave propagation direction on the piezoelectric substrate and each including a pair of busbars and a plurality of electrode fingers;
- wherein
- at least one of the plurality of IDT electrodes includes a first pitch portion in which an electrode finger pitch is relatively wide and a second pitch portion in which an electrode finger pitch is relatively narrow;
- a portion in which the plurality of electrode fingers adjacent to each other overlap each other in the acoustic wave propagation direction is an intersecting region, the intersecting region includes a central region located on a central side in a direction in which the plurality of electrode fingers extend, and a pair of edge regions are provided on both sides of the central region in the direction in which the plurality of electrode fingers extend and including respective tip portions of the plurality of electrode fingers;
- in each of the plurality of IDT electrodes, a pair of gap regions is between the intersecting region and the pair of busbars;
- a plurality of mass addition films overlap portions of the plurality of electrode fingers in the pair of edge regions in a plan view;
- the plurality of mass addition films includes a plurality of first mass addition films in the first pitch portion and a plurality of second mass addition films in the second pitch portion;
- one of the plurality of first mass addition films overlaps at least one of the plurality of electrode fingers in a plan view;
- each of the plurality of second mass addition films overlaps one of the plurality of electrode fingers but does not overlap another of the plurality of electrode fingers adjacent to the one of the plurality of electrode fingers in a plan view;
- and
- a length of one of the plurality of first mass addition films along the acoustic wave propagation direction is greater than a length of one of the plurality of second mass addition films along the acoustic wave propagation direction.
10 more elements
An acoustic wave device comprising:
- a piezoelectric substrate;
- and
- a plurality of interdigital transducer (IDT) electrodes extending in an acoustic wave propagation direction on the piezoelectric substrate and each including a pair of busbars and a plurality of electrode fingers;
- wherein
- at least one of the plurality of IDT electrodes includes a first pitch portion in which an electrode finger pitch is relatively wide and a second pitch portion in which an electrode finger pitch is relatively narrow;
- a portion in which the plurality of electrode fingers adjacent to each other overlap each other in the acoustic wave propagation direction is an intersecting region, the intersecting region includes a central region located on a central side in a direction in which the plurality of electrode fingers extend, and a pair of edge regions are provided on both sides of the central region in the direction in which the plurality of electrode fingers extend and include respective tip portions of the plurality of electrode fingers;
- in each of the plurality of IDT electrodes, a pair of gap regions is between the intersecting region and the pair of busbars;
- a width of each of the plurality of electrode fingers in the first pitch portion in the pair of edge regions is greater than a width of each of the plurality of electrode fingers in the central region;
- a width of each of the plurality of electrode fingers in the second pitch portion in the pair of edge regions is equal to or less than a width of each of the plurality of electrode fingers in the central region;
- a plurality of mass addition films overlap portions of the plurality of electrode fingers in the first pitch portion and the second pitch portion located in the pair of edge regions in a plan view;
- and
- each of the plurality of mass addition films overlaps the plurality of electrode fingers and a portion located between the plurality of electrode fingers in a plan view.
9 more elements
Dependencies are inferred from the claim text.