Title:
ELASTIC WAVE DEVICE
Document Type and Number:
WIPO Patent Application WO/2023/112652
Kind Code:
A1
Abstract:
Provided is an elastic wave device with which polarization reversal can be suppressed. This elastic wave device 10 comprises: a package substrate 2 having a first principal surface 2a; and an elastic wave element chip 1 mounted on the first principal surface 2a of the package substrate 2. The elastic wave element chip includes: a piezoelectric layer (piezoelectric substrate 3) having a second principal surface 3a and a third principal surface opposing each other; and a plurality of IDT electrodes which are provided to, from between the second principal surface 3a and the third principal surface, the second principal surface 3a which is located on the first principal surface 2a, each of the IDT electrodes having a plurality of electrode fingers. The first principal surface 2a of the package substrate 2 has a first side 2d and a second side 2e opposing each other. The second principal surface 3a of the piezoelectric layer includes, in plan view: a first edge part 3d positioned on the first side 2d from between the first side 2d and the second side 2e; and a second edge part 3e opposing the first edge part 3d. In plan view, a first outer circumferential edge-to-edge distance A1 between the first side 2d and the first edge part 3d is longer than a second outer circumferential edge-to-edge distance A2 between the second side 2e and the second edge part 3e. The piezoelectric layer has a Z axis which serves as a crystalline axis. The Z axis is inclined with respect to the thickness direction of the piezoelectric layer so as to be inclined toward the first edge part 3d side from the third principal surface to the second principal surface 3a of the piezoelectric layer. When viewing the IDT electrodes from a direction orthogonal to the direction in which the plurality of electrode fingers extend, a region in which adjacent electrode fingers overlap each other is an intersecting region, and a dimension of the intersecting region along the direction in which the plurality of electrode fingers extend is an intersecting width. When the IDT electrode positioned closest to the first edge part 3d among the plurality of IDT electrodes is designated as an edge-side IDT electrode, the product of the intersecting width and the logarithm of the plurality of electrode fingers of the edge-side IDT electrode is the smallest among the products of the intersecting width and the logarithm of the plurality of electrode fingers of the plurality of IDT electrodes.
Inventors:
SHODA CHIHIRO (JP)
SHIN YASUAKI (JP)
OKANO YOSHIHISA (JP)
YASUDA JUNPEI (JP)
SHIN YASUAKI (JP)
OKANO YOSHIHISA (JP)
YASUDA JUNPEI (JP)
Application Number:
PCT/JP2022/043805
Publication Date:
June 22, 2023
Filing Date:
November 28, 2022
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/25; H03H9/64; H03H9/72
Foreign References:
| JP2018186481A | 2018-11-22 | |||
| JP2018006799A | 2018-01-11 | |||
| JP2006180192A | 2006-07-06 | |||
| JP2012253497A | 2012-12-20 |
Attorney, Agent or Firm:
OSAKA FRONT (JP)
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