US 2010/0060110 A1Published application

Multi-Layer Piezoelectric Element and Injection Apparatus Employing The Same

AssigneesKYOCERA Corporation, Siemens Aktiengesellschaft

InventorsMasahiro Inagaki, Takami Sakamoto, Harald-Johannes Kastl, Carsten Schuh, Bernhard Doellgast, Atsushi Ochi

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Abstract

A multi-layer piezoelectric element which undergo less change in the amount of displacement and shows high durability during continuous operation under a high voltage and pressure over a long period are provided. The multi-layer piezoelectric element comprises a stack having metal layers and piezoelectric layers stacked one on another, and a pair of external electrodes formed on the side faces of the stack, wherein at least one of the metal layers is stress relieving layer having partial metal layers scattered between the two piezoelectric layers and voids, wherein junction sections are formed between the two piezoelectric layers to join and are disposed on both sides of an imaginary straight line drawn to connect the center of width of one of the external electrodes and the center of width of the other of the external electrodes in a plane including the stress relieving perpendicular to the stacking direction.

Claims10

Dependent claims

A multi-layer piezoelectric element comprising:

a stack having a plurality of piezoelectric layers and a plurality of metal layers, the piezoelectric layers and the metal layers being stacked one on another;
a pair of external electrodes formed on the side faces of the stack,
wherein at least one of the plurality of metal layers is a stress relieving layer having a plurality of partial metal layers and voids, the partial metal layers are scattered between two piezoelectric layers sandwiching the stress relieving layer in the direction of stacking, and
wherein a plurality of junction sections are formed between said two piezoelectric layers to join said two piezoelectric layers with each other, the junction sections being disposed on both sides of an imaginary straight line which is drawn so as to connect the center in the direction of width of one of the external electrodes and the center in the direction of width of the other of the external electrodes in a plane that includes the stress relieving layer and is perpendicular to the stacking direction.

1 more element

Dependencies are inferred from the claim text.