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US 12,348,212 B2Granted
Elastic wave device and ladder filter
AssigneeMurata Manufacturing Co., Ltd.
InventorsTetsuya Kimura, Naohiro Nodake
Life of this patent
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Abstract
An elastic wave device includes a piezoelectric film made of lithium niobate or lithium tantalate, and a first electrode finger and a second electrode finger opposing each other in a direction intersecting a thickness direction of the piezoelectric film. When an average thickness of the piezoelectric film is d and a distance between centers of the first electrode finger and the second electrode finger is p, d/p is about 0.5 or less. The first electrode finger and the second electrode finger are connected to the first and second bus bars, respectively. The first and second bus bars include corner portions. At least one of corner portions of the first and second bus bars is outside a cavity portion when viewed in plan view.
Claims19
An elastic wave device comprising:
- a support substrate including a first main surface and a recessed portion at the first main surface;
- a piezoelectric film made of lithium niobate or lithium tantalate, laminated on the first main surface of the support substrate, and defining a cavity portion with the recessed portion;
- and
- an electrode on the piezoelectric film and including first and second bus bars, a first electrode finger connected to the first bus bar, and a second electrode finger connected to the second bus bar;
- wherein
- the first and second bus bars include a plurality of corner portions when viewed in a plan view;
- the elastic wave device is configured to use a bulk wave in a thickness slip mode;
- and at least one of the plurality of corner portions of the first and second bus bars that is closest to the first and second electrode fingers is outside the cavity portion when viewed in the plan view;
- and
- an outer edge of at least one of the plurality of corner portions of the first and second bus bars is curved.
7 more elements
An elastic wave device comprising:
- a support substrate including a first main surface and a recessed portion open to the first main surface;
- a piezoelectric film made of lithium niobate or lithium tantalate, laminated on the first main surface of the support substrate and defining a cavity portion with the recessed portion together with the support substrate;
- and
- an electrode on the piezoelectric film and including first and second bus bars, a first electrode finger connected to the first bus bar, and a second electrode finger connected to the second bus bar;
- wherein
- the first and second bus bars include a plurality of corner portions when viewed in a plan view;
- an outer edge of at least one of the plurality of corner portions of the first and second bus bars is curved;
- when a thickness of the piezoelectric film is d and a distance between centers of the first electrode finger and second electrode finger is p, d/p is about 0.5 or less;
- at least one of the plurality of corner portions of the first and second bus bars that is closest to the first and second electrode fingers is outside the cavity portion when viewed in the plan view;
- and
- a portion of at least one of the first and second busbars that includes the at least one of the plurality of corner portions that is outside the cavity portion overlaps with the cavity portion in the plan view.
8 more elements
An elastic wave device comprising:
- a support substrate including a first main surface and a recessed portion at the first main surface;
- a piezoelectric film laminated on the first main surface of the support substrate and defining a cavity portion with the recessed portion;
- and
- an interdigital transducer (IDT) electrode on the piezoelectric film so that a portion of the IDT electrode overlaps the cavity portion;
- wherein
- the IDT electrode includes first and second bus bars, a plurality of first electrode fingers connected to the first bus bar, and a plurality of second electrode fingers connected to the second bus bar;
- the plurality of first electrode fingers and the plurality of second electrode fingers are interleaved with each other;
- the first and second bus bars include a plurality of corner portions when viewed in a plan view;
- a second-layer electrode pattern is laminated on at least a portion of the first and second bus bars;
- at least one of the plurality of corner portions of the first and second bus bars that is closest to the plurality of first and second electrode fingers is outside the cavity portion when viewed in the plan view;
- a portion of at least one of the first and second busbars that includes the at least one of the plurality of corner portions that is outside the cavity portion overlaps with the cavity portion in the plan view;
- the second-layer electrode pattern includes a plurality of corner portions, and at least one of the plurality of corner portions of the second-layer electrode pattern is outside the cavity portion when viewed in the plan view;
- and
- an outer edge of at least one of the plurality of corner portions of the second-layer electrode pattern is curved.
11 more elements
Dependencies are inferred from the claim text.