US 12,413,206 B2
Acoustic wave device
Hisashi Yamazaki, Nagaokakyo (JP); Seiji Kai, Nagaokakyo (JP); and Takeshi Nakao, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Mar. 29, 2022, as Appl. No. 17/706,723.
Claims priority of provisional application 63/168,296, filed on Mar. 31, 2021.
Prior Publication US 2022/0321097 A1, Oct. 6, 2022
Int. Cl. H03H 9/54 (2006.01); H03H 9/02 (2006.01); H03H 9/13 (2006.01)
CPC H03H 9/54 (2013.01) [H03H 9/02007 (2013.01); H03H 9/02228 (2013.01); H03H 9/13 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An acoustic wave device comprising:
a support including a support substrate;
a piezoelectric layer on the support;
a functional electrode at the piezoelectric layer;
a support frame on the piezoelectric layer and surrounding the functional electrode in a plan view in a stacking direction of the support and the piezoelectric layer; and
a lid covering an opening of the support frame; wherein
the support includes a first cavity at a position overlapping at least a portion of the functional electrode in the plan view in the stacking direction of the support and the piezoelectric layer;
a second cavity defined by the piezoelectric layer, the support frame, and the lid is provided between the piezoelectric layer and the lid;
the piezoelectric layer includes a through hole communicating with the first cavity and the second cavity; and
the first cavity and the second cavity are under vacuum.