Ngk Insulators, Inc.

Akifumi Morishita

Masayuki Uetani

Tomohiko Hibino

Takao Ohnishi

Takatomo Ogata

Daishi Tanabe

A first detection electrode is provided on an insulating layer. A second detection electrode is provided away from the first detection electrode on the insulating layer, and forms a capacitance together with the first detection electrode. The protection layer covers the first detection electrode and the second detection electrode, has a thickness d satisfying 1 μm≤d≤10 μm, and is made of zirconia or alumina. The protection layer is a sintered body.

Capacitive sensor

An electrode embedded ceramic structure includes: a first ceramic layer; an electrode layer formed on the first ceramic layer; and a second ceramic layer covering the first ceramic layer and the electrode layer, the second ceramic layer being thinner than the first ceramic layer. In a cross section of the first ceramic layer, the electrode layer, and the second ceramic layer along a laminating direction in this electrode embedded ceramic structure, T1 and T2 satisfy Equation (T2−T1)/T2≤0.15, where T1 denotes a least thickness in the second ceramic layer, and T2 denotes an average thickness of the second ceramic layer.

Electrode embedded ceramic structure

A piezoelectric element includes a piezoelectric body having a main phase configured by lead zirconate titanate and a heterogenous phase configured by a different component to lead zirconate titanate, and a pair of electrodes provided on the piezoelectric body. The piezoelectric body has a surface region within 10 &#x3bc;m of a surface, and an inner region more than 10 &#x3bc;m from the surface. A surface area coverage of the heterogenous phase in a cross section of the surface region is at least 0.75% greater than a surface area coverage of the heterogenous phase in a cross section of the inner region.

Piezoelectric element

The piezoelectric element comprises a piezoelectric body extending in a lateral direction and a first and second electrodes that are provided on the piezoelectric body. The piezoelectric body has an active portion sandwiched between the first and second electrodes in a thickness direction that is vertical to the lateral direction, and an inactive portion connected to the active portion in the lateral direction. The first electrode has an active electrode portion disposed on the active portion. The active electrode portion includes an interface region that is adjacent to the interface of the active portion and the inactive portion in the lateral direction, and an inner region that is separated from the interface of the active portion and the inactive portion in the lateral direction. The cross sectional surface area per unit length of the interface region in the cross section of the active electrode portion is greater than the cross sectional area per unit length of the inner region.

A piezoelectric/electrostrictive material is composed of Mn and a compound of Pb(Zn, Nb)O&#x2014;Pb(Ni, Nb)O&#x2014;Pb(Zr, Ti)O. A ratio of a molar amount of Mn relative to a sum of respective molar amounts of Ni, Zn, Ti, Zr, Nb and Mn is at least 0.001 to no more than 0.015. A ratio of a molar amount of Nb relative to a sum of respective molar amounts of Ni and Zn is at least 2.007 to no more than 2.125.

Growing community of inventors

Nagoya, Japan

Akifumi Morishita