Taiyo Yuden Co., Ltd.

Sumiaki Kishimoto

Hiroyuki Shimizu

Takayuki Goto

Tomohiro Harada

Yukihiro Konishi

Yutaka Doshida

Keiichi Hatano

Shigeo Ishii

Gouki Watanabe

Hiroshi Hamada

Yukihiro Matsui

Yuichi Namikawa

Ryo Ito

Yuuhei Ueyama

A multilayer piezoelectric ceramic is such that: its piezoelectric ceramic layers do not contain lead as a constituent element, and have a perovskite compound expressed by the composition formula LiNaKNbO(where 0.02<x≤0.1, 0.02<x+y≤1), as the primary component; and the internal electrode layers are constituted by a metal containing silver by 80 percent by mass or more, and contain ceramic grains containing the same elements found in the primary component. The multilayer piezoelectric element has a long lifespan, and whose internal electrode layers have a high content percentage of silver.

Multilayer piezoelectric ceramic and method for manufacturing same, multilayer piezoelectric element, as well as piezoelectric vibration apparatus

A multilayer piezoelectric element includes a ceramic body formed by a piezoelectric ceramic, and having first and second end face facing a longitudinal direction, first and second principal faces facing a thickness direction perpendicular to the longitudinal direction. A pair of external electrodes cover the first and second end faces, extend from the first and second end faces onto the first principal face via ridge parts connecting the end faces with the principal faces, and project in the thickness direction on the first principal face. Multiple internal electrodes are stacked inside the ceramic body and are connected alternately to the pair of external electrodes along the thickness direction. A surface electrode is provided on at least one of the first and second principal faces, and connected to the external electrode different from the one to which the internal electrode adjacent in the thickness direction is connected.

Multilayer piezoelectric element, piezoelectric vibration apparatus, and electronic device

A driving device generates a driving signal and outputs the driving signal to a piezoelectric element, the driving signal having a waveform obtained by using, as a first modulated wave, a first low-frequency wave having a frequency of 1 Hz or more and less than 100 Hz, using, as a second modulated wave, a waveform obtained by modulating an amplitude of a second low-frequency wave having a frequency of 100 Hz or more and 300 Hz or less with the first modulated wave, and modulating a high-frequency wave having a frequency of 20 kHz or more and 100 kHz or less with the second modulated wave.

Driving device, tactile sensation providing apparatus, and driving method

Provided is a driving apparatus that sets a signal wave in a low-frequency region having a frequency of 10 Hz or more and 250 Hz or less as a modulating wave and outputs to a piezoelectric actuator a driving signal having a waveform obtained by modulating an amplitude of a sine wave in a high-frequency region having a frequency of 20 kHz or more and 40 kHz or less with the modulating wave.

Driving apparatus, vibration generating apparatus, electronic apparatus, and driving method

A multilayer piezoelectric ceramic is constituted by: piezoelectric ceramic layers which do not contain lead as a constituent element, have a perovskite compound expressed by the composition formula LiNaKNbO(where 0.02&#x3c;x&#x2264;0.1, 0.02&#x3c;x+y&#x2264;1) as the primary component, and contain 0.2 to 3.0 mol of Li relative to 100 mol of the primary component; and internal electrode layers which are constituted by a metal that contains silver by 80 percent by mass or more; wherein the multilayer piezoelectric ceramic is such that Li compounds other than the primary component are localized therein. The multilayer piezoelectric element can offer excellent insulating property.

Multilayer piezoelectric ceramic and method for manufacturing same, multilayer piezoelectric element, as well as piezoelectric vibration device

A piezoelectric ceramic, which does not contain lead as a constituent element, is characterized in that: its primary component is a perovskite compound expressed by the composition formula (BiNaBa)(TiMn)O(where 0.01&#x2264;x&#x2264;0.25, 0.001&#x2264;y&#x2264;0.020); and the coefficient of variation (CV) in grain size among the grains contained therein is 35 percent or lower. The piezoelectric ceramic presents an improved dielectric loss tangent tan &#x3b4;.

Piezoelectric ceramic and method for manufacturing same, as well as piezoelectric element

In an embodiment, a multilayer piezoelectric element includes a multilayer piezoelectric body and multiple internal electrodes. The multilayer piezoelectric body has a pair of principal faces in a first-axis direction, a pair of end faces in a second-axis direction crossing at right angles with the first-axis direction and defining the longitudinal direction, and a pair of side faces in a third-axis direction crossing at right angles with the first-axis direction and second-axis direction. The multiple internal electrodes are placed inside the multilayer piezoelectric body and stacked in the first-axis direction. Among the multiple internal electrodes, a center internal electrode placed at the center part of the multilayer piezoelectric body is such that its first cross-sectional shape, as viewed from the third-axis direction, has undulations greater than the undulations of the second cross-sectional shape of the center internal electrode as viewed from the second-axis direction.

A multilayer piezoelectric element includes a ceramic base body, a pair of external electrodes, multiple internal electrodes, and surface electrodes. The pair of external electrodes cover a pair of end faces and extend from the pair of end faces along a pair of principal faces and a pair of side faces. The multiple internal electrodes are stacked inside the ceramic base body along the thickness direction, and are connected alternately to one or the other of the pair of external electrodes along the thickness direction. The surface electrodes extend from the pair of external electrodes along the pair of principal faces, and are each divided in the longitudinal direction at a position near, of the pair of external electrodes, the external electrode to which the internal electrode adjacent to the principal face is connected.

A multi-layer piezoelectric ceramic component includes: a piezoelectric ceramic body having a cuboid shape, having upper and lower surfaces facing in a thickness direction, first and second end surfaces facing in a length direction, and a pair of side surfaces facing in a width direction, and including first and second regions; first internal electrodes in the first region; second internal electrodes in the second region; third internal electrodes in the first and second regions; a first terminal electrode formed on the first end surface and electrically connected to the first internal electrodes; a second terminal electrode formed on the first end surface and electrically connected to the second internal electrodes; a third terminal electrode formed on the second end surface and electrically connected to the third internal electrodes; a first surface electrode formed on the upper surface; and a second surface electrode formed on the lower surface.

Multi-layer piezoelectric ceramic component and piezoelectric device

A multi-layer piezoelectric ceramic component includes: a piezoelectric ceramic body having a cuboid shape having upper and lower surfaces facing in a thickness direction, first and second end surfaces facing in a length direction, and a pair of side surfaces facing in a width direction; first internal electrodes formed in the piezoelectric ceramic body and drawn to the first end surface; second internal electrodes formed in the piezoelectric ceramic body and drawn to the second end surface; a first terminal electrode formed on the first end surface; and a second terminal electrode formed on the second end surface, the first and second internal electrodes each having a width equal to a distance between the pair of side surfaces, at least one of the pair of side surfaces including a groove extending in non-parallel with the length direction.

A multi-layer piezoelectric ceramic component includes: a piezoelectric ceramic body having a cuboid shape, having upper and lower surfaces facing in a thickness direction, first and second end surfaces facing in a length direction, and a pair of side surfaces facing in a width direction, and including first and second regions; first internal electrodes in the first region; second internal electrodes in the second region; third internal electrodes in the first and second regions; a first terminal electrode formed on the first end surface and electrically connected to the first internal electrodes; a second terminal electrode formed on the first end surface and electrically connected to the second internal electrodes; and a third terminal electrode formed on the second end surface and electrically connected to the third internal electrodes, the first, second, and third internal electrodes each having a width equal to a distance between the pair of side surfaces.

Multi-layer piezoelectric ceramic component-mounted piezoelectric device

A multilayer piezoelectric element includes a ceramic base body, a pair of external electrodes, multiple internal electrodes, and surface electrodes. The ceramic base body is formed by a piezoelectric ceramic. The pair of external electrodes cover a pair of end faces. The multiple internal electrodes are stacked inside the ceramic base body along a thickness direction crossing at right angles with a longitudinal direction, and connected alternately to the pair of external electrodes in the thickness direction. The surface electrodes are provided on a pair of principal faces, respectively, and are each connected to the external electrode different from the one to which the internal electrode adjacent in the thickness direction is connected. The pair of external electrodes have a higher porosity than the surface electrodes.

A piezoelectric element which is a single-layer or laminated piezoelectric element has a first electrode, a second electrode, and a piezoelectric ceramic layer. The first electrode and second electrode contain silver by 50 percent by weight or more. The piezoelectric ceramic layer is placed between the first electrode and second electrode, and constituted by a polycrystalline substance of alkali niobate piezoelectric ceramic containing at least one alkali earth metal being calcium, strontium, or barium, and silver. According to this constitution, the electrical resistance and piezoelectric property can be improved, and consequently high reliability and good piezoelectric characteristics can be achieved.

Piezoelectric element and method of manufacturing the same

A piezoelectric ceramic speaker includes a piezoelectric element using a vibration sheet formed with piezoelectric ceramic having a primary phase constituted by ceramic grains of perovskite crystal structure containing Pb, Nb, Zn, Ti, and Zr, and a secondary phase constituted by ZnO grains, wherein the primary phase is constituted by ceramic grains expressed by a composition formula Pb {(ZrTi)&#xb7;(NiNb)&#xb7;(ZnNb)}O(where 0&#x3c;x&#x2264;0.85, 0&#x2264;y&#x3c;1, 0&#x3c;z&#x3c;1, x+y+z=1, and 0.45&#x2264;a&#x2264;0.60); and an enclosure which encloses the piezoelectric element.

Piezoelectric ceramic speaker using vibration sheet formed with piezoelectric ceramic

A piezoelectric ceramic has a primary phase constituted by ceramic grains of perovskite crystal structure containing Pb, Nb, Zn, Ti, and Zr, and a secondary phase constituted by ZnO grains present sporadically in the primary phase. The piezoelectric ceramic of high kr and high specific dielectric constant can be sintered at low temperature and exhibit minimal characteristics variations.

Growing community of inventors

Takasaki, Japan

Sumiaki Kishimoto