Title:
ELASTIC WAVE DEVICE
Document Type and Number:
WIPO Patent Application WO/2023/136292
Kind Code:
A1
Abstract:
Provided is an elastic wave device that can suppress loss degradation without easily damaging the elastic wave device. An elastic wave device 10 according to the present invention comprises: a piezoelectric substrate 12 having a support member 13 including a support substrate 16, and a piezoelectric layer 14 provided on the support member 13 and comprising lithium tantalite or lithium niobate; and an IDT electrode 11 provided on the piezoelectric layer 14 and having a pair of bus bars and a plurality of electrode fingers (plurality of first and second electrode fingers 28, 29). If the thickness of the piezoelectric layer 14 is denoted by d, and the distance between the centers of adjacent electrode fingers is denoted by p, d/p is less than or equal to 0.5. Some of the plurality of electrode fingers are connected to one bus bar of the pair of bus bars. The remaining electrode fingers are connected to the other bus bar. The portion of electrode fingers connected to the one bus bar and the remaining electrode fingers connected to the other bus bar are interdigitated. A region in which adjacent electrode fingers overlap if viewed from an electrode finger facing direction in which adjacent electrode fingers face each other is an intersecting region F. Regions positioned between the intersecting region F and the pair of bus bars are a pair of gap regions. The intersecting region F comprises a central region, and a pair of edge regions arranged so as to sandwich the central region in the electrode finger extension direction in which the plurality of electrode fingers extend. The support member 13 includes a support part 13a supporting the piezoelectric layer 14, and a non-support part 13b not supporting the piezoelectric layer 14. In a plan view, the non-support part 13b of the support member 13 overlaps the central region and 90% or more of a portion positioned between electrode fingers in the pair of edge regions. A through hole (through hole 14c) is provided in the piezoelectric layer 14 in 50% or more of a portion positioned between the electrode fingers, the portion thereof overlapping the pair of gap regions in a plan view. The support part 13a of the support member 13 is provided so as to overlap, in a plan view, a portion at which the electrode fingers are provided in the pair of gap regions.
Inventors:
DAIMON KATSUYA (JP)
Application Number:
PCT/JP2023/000610
Publication Date:
July 20, 2023
Filing Date:
January 12, 2023
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/25; H03H9/145
Domestic Patent References:
| WO2016098526A1 | 2016-06-23 | |||
| WO2018163860A1 | 2018-09-13 |
Foreign References:
| US20210167756A1 | 2021-06-03 |
Attorney, Agent or Firm:
OSAKA FRONT (JP)
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