Title:
ELASTIC WAVE DEVICE
Document Type and Number:
WIPO Patent Application WO/2023/085408
Kind Code:
A1
Abstract:
Provided is an elastic wave device capable of suppressing unwanted waves at a frequency lower than and around a resonance frequency. An elastic wave device 10 according to the present invention comprises: a support member including a support substrate; a piezoelectric layer 14 provided on the support member, the piezoelectric layer 14 being formed from lithium niobate or lithium tantalate, and having a first main surface 14a and a second main surface 14b that face mutually opposite directions; and an IDT electrode 11 provided to the first main surface 14a of the piezoelectric layer 14. In a plan view viewed along the layering direction of the support member and the piezoelectric layer 14, an acoustic reflector is formed at a position overlapping at least a portion of the IDT electrode 11. The IDT electrode 11 has: a first busbar 26 and a second busbar that face one another; a plurality of first electrode fingers, one end of each of the first electrode fingers being connected to the first busbar 26; and a plurality of second electrode fingers 29 inserted between the plurality of first electrode fingers, one end of each of the second electrode fingers 29 being connected to the second busbar. The ratio d/p is equal to or less than 0.5, where d is the thickness of the piezoelectric layer 14, and p is the distance between the centers of adjacent first and second electrode fingers. At least one through-hole 17 is provided in the piezoelectric layer 14. One through-hole 17 is provided at a portion in the piezoelectric layer 14 located between the first busbar 26 and any one of the plurality of second electrode fingers 29. The piezoelectric layer 14 has a cutout-side surface 14c, the cutout-side surface 14c being connected to the first main surface 14a and the second main surface and facing the through-hole 17, and the inclination angle θp of the cutout-side surface 14c being other than 0°, where the inclination angle θp is the angle at which the cutout-side surface 14c is inclined relative to a line normal to the first main surface 14a and the second main surface.
Inventors:
DAIMON KATSUYA (JP)
KIMURA TETSUYA (JP)
KIMURA TETSUYA (JP)
Application Number:
PCT/JP2022/042140
Publication Date:
May 19, 2023
Filing Date:
November 11, 2022
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/25
Domestic Patent References:
| WO2021060509A1 | 2021-04-01 | |||
| WO2021200835A1 | 2021-10-07 | |||
| WO2022210809A1 | 2022-10-06 |
Foreign References:
| JP2014110457A | 2014-06-12 |
Attorney, Agent or Firm:
OSAKA FRONT (JP)
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