US 12,439,823 B2
Piezoelectric device
Yutaka Kishimoto, Nagaokakyo (JP); and Shinsuke Ikeuchi, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Aug. 9, 2022, as Appl. No. 17/883,742.
Application 17/883,742 is a continuation of application No. PCT/JP2021/006585, filed on Feb. 22, 2021.
Claims priority of application No. 2020-030351 (JP), filed on Feb. 26, 2020.
Prior Publication US 2022/0384708 A1, Dec. 1, 2022
Int. Cl. H10N 30/072 (2023.01); H04R 17/00 (2006.01); H10N 30/06 (2023.01); H10N 30/50 (2023.01); H10N 30/853 (2023.01); H10N 30/87 (2023.01)
CPC H10N 30/072 (2023.02) [H04R 17/00 (2013.01); H10N 30/06 (2023.02); H10N 30/50 (2023.02); H10N 30/8542 (2023.02); H10N 30/87 (2023.02); H10N 30/871 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A piezoelectric device comprising:
a base including:
a first principal surface and a second principal surface positioned opposite to the first principal surface; and
a recess at the first principal surface; and
a layered portion provided on the first principal surface of the base so as to cover the recess from above; wherein
the layered portion includes, at a position at least above the recess, a single crystal piezoelectric layer and a pair of electrode layers to apply voltage to the single crystal piezoelectric layer;
at least a portion of the pair of electrode layers includes a lower electrode layer;
the lower electrode layer extends along a surface of the single crystal piezoelectric layer, the surface being closer to the base; and
the lower electrode layer is present only inside the recess.