US 12,456,959 B2
Piezoelectric element
Yutaka Kishimoto, Nagaokakyo (JP); Shinsuke Ikeuchi, Nagaokakyo (JP); Masayuki Suzuki, Nagaokakyo (JP); and Fumiya Kurokawa, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Mar. 3, 2022, as Appl. No. 17/685,437.
Application 17/685,437 is a continuation of application No. PCT/JP2020/020537, filed on May 25, 2020.
Claims priority of application No. 2019-166218 (JP), filed on Sep. 12, 2019.
Prior Publication US 2022/0271728 A1, Aug. 25, 2022
Int. Cl. H03H 9/02 (2006.01); H03H 3/02 (2006.01); H03H 9/13 (2006.01); H03H 9/17 (2006.01)
CPC H03H 9/02133 (2013.01) [H03H 3/02 (2013.01); H03H 9/02031 (2013.01); H03H 9/02228 (2013.01); H03H 9/13 (2013.01); H03H 9/174 (2013.01); H03H 9/176 (2013.01); H03H 2003/023 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A piezoelectric element comprising:
a single-crystal piezoelectric layer including a first surface, a second surface on an opposite side to the first surface, and a through-hole penetrating from the first surface to the second surface;
a first electrode layer on a first surface side of the single-crystal piezoelectric layer;
a second electrode layer on a second surface side of the single-crystal piezoelectric layer and including a hole continuous with the through-hole, at least a portion of the second electrode layer being opposed to the first electrode layer with the single-crystal piezoelectric layer interposed therebetween; and
a third electrode layer on a side of the second electrode layer opposite to the single-crystal piezoelectric layer and including at least a portion outside of an edge of the hole with a distance maintained relative to the edge of the hole when viewed in a direction perpendicular or substantially perpendicular to the second surface; wherein
the second electrode layer is made of Pt, Ti, Al, Cu, Au, Ag, or Mg, or an alloy including at least one of Pt, Ti, Al, Cu, Au, Ag, or Mg as a main ingredient; and
the third electrode layer is made of Ni or an alloy including Ni as a main ingredient.