Title:
ELASTIC WAVE DEVICE
Document Type and Number:
WIPO Patent Application WO/2023/002823
Kind Code:
A1
Abstract:
The present invention provides an elastic wave device that can suppress an increase in insertion loss. An elastic wave device 10 according to the present invention comprises: a support member that includes a support substrate; a piezoelectric layer 14 that is a lithium niobate layer or a lithium tantalate layer and is provided on the support member; a pair of busbars (first and second busbars 26, 27) provided on the piezoelectric layer 14; and an IDT electrode 11 having a plurality of electrode fingers (first and second electrode fingers 28, 29). An acoustic reflection part is provided on the support member. The acoustic reflection part overlaps at least a portion of the IDT electrode 11 in a plan view. When d represents the thickness of the piezoelectric layer 14 and p represents the distance between the centers of adjacent electrode fingers, d/p is 0.5 or less. Of the plurality of electrode fingers, a portion of the electrode fingers are connected to one busbar of the IDT electrode 11, the remaining electrode fingers of the plurality of electrode fingers are connected to the other busbar, and the plurality of electrode fingers connected to the one busbar and the plurality of electrode fingers connected to the other busbar are interdigitated with each other. A region in which adjacent electrode fingers overlap when viewed in the 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 busbars are a pair of gap regions (first and second gap regions G1, G2). An additive film 23 having a higher dielectric constant and density than silicon oxide is provided in at least one of the pair of gap regions.
Inventors:
DAIMON KATSUYA (JP)
Application Number:
PCT/JP2022/025940
Publication Date:
January 26, 2023
Filing Date:
June 29, 2022
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/145; H03H9/25
Domestic Patent References:
| WO2019049608A1 | 2019-03-14 |
Foreign References:
| JP2019080093A | 2019-05-23 | |||
| JP6819834B1 | 2021-01-27 | |||
| JP2021100280A | 2021-07-01 | |||
| JP2017175276A | 2017-09-28 | |||
| JP2014131351A | 2014-07-10 | |||
| JP2018191112A | 2018-11-29 | |||
| JP2018182544A | 2018-11-15 |
Attorney, Agent or Firm:
OSAKA FRONT (JP)
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