Patent ID: 7646136
Filing Date: 2010-01-12
Classification: H01L,H02N

Abstract:
1. A piezoelectric element formed by alternately stacking substantially rectangular piezoelectric layers and internal electrode layers, wherein the internal electrode layers are positive electrode layers and negative electrode layers which are alternately arranged in a stacking direction with each of the piezoelectric layers interposed between an associated one of the positive electrode layers and an associated one of the negative electrode layers, the positive electrode layers include a first positive electrode layer provided on a principle surface of one of the piezoelectric layers and a second positive electrode layer provided on a principle surface of different one of the piezoelectric layers from the one of the piezoelectric layers in which the first positive electrode layer is provided, the negative electrode layers include a first negative electrode layer provided on a principle surface of one of the piezoelectric layers and a second negative electrode layer provided on a principle surface of different one of the piezoelectric layers from the one of the piezoelectric layers in which the first negative electrode layer is provided, each of the first positive electrode layer and the first negative electrode layer includes four divided electrodes provided in four areas, respectively, the four areas being obtained by dividing a principle surface of an associated one of the piezoelectric layers into two areas in a lengthwise direction and two areas in a widthwise direction, and a connecting electrode for connecting a pair of the divided electrodes formed on diagonally opposite two of the four areas along a first diagonal direction on the principle surface of the associated one of the piezoelectric layers, and each of the second positive electrode layer and the second negative electrode layer includes four divided electrodes provided in the four areas, respectively, and a connecting electrode for connecting a pair of the divided electrodes formed on diagonally opposite two of the four areas along a second diagonal direction on the principle surface of the associated one of the piezoelectric layers.