US 12,425,001 B2
Acoustic wave device and ladder filter
Katsuya Daimon, Nagaokakyo (JP); and Sho Nagatomo, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Apr. 21, 2023, as Appl. No. 18/137,631.
Application 18/137,631 is a continuation of application No. PCT/JP2021/045960, filed on Dec. 14, 2021.
Claims priority of application No. 2020-210371 (JP), filed on Dec. 18, 2020.
Prior Publication US 2023/0261634 A1, Aug. 17, 2023
Int. Cl. H03H 9/02 (2006.01); H03H 9/145 (2006.01); H03H 9/25 (2006.01); H03H 9/64 (2006.01)
CPC H03H 9/02992 (2013.01) [H03H 9/02866 (2013.01); H03H 9/145 (2013.01); H03H 9/25 (2013.01); H03H 9/6483 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An acoustic wave device comprising:
a support substrate;
a piezoelectric layer provided directly or indirectly on the support substrate, the piezoelectric layer including a first main surface and a second main surface that face away from each other, the second main surface being closer to the support substrate; and
an IDT electrode provided on the first main surface of the piezoelectric layer; wherein
the IDT electrode includes a first comb electrode including a plurality of first electrode fingers and a first busbar and a second comb electrode including a plurality of second electrode fingers interdigitated with the plurality of first electrode fingers and a second busbar, a region in which the first electrode fingers and the second electrode fingers overlap each other in a direction perpendicular or substantially perpendicular the first electrode fingers and the second electrode fingers is an overlap region, the overlap region includes a middle region located centrally in a direction in which the first electrode fingers and the second electrode fingers extend, a first edge region located on an outer side of the middle region in the direction in which the first electrode fingers and the second electrode fingers extend, the first edge region being closer to the first busbar, and a second edge region located on the outer side of the middle region in the direction in which the first electrode fingers and the second electrode fingers extend, the second edge region being closer to the second busbar, a first gap region is present between the first busbar and the first edge region, a second gap region is present between the second busbar and the second edge region, and the acoustic wave device further includes a conductive layer that is provided on the second main surface of the piezoelectric layer to overlap at least some portions of the first and second edge regions in plan view and at least some portions of the first and second busbars in plan view.