Patent ID: 6747398
Filing Date: 2004-06-08
Classification: H01L

Abstract:
A multilayer piezoelectric device comprising:a piezoelectric substrate; a plurality of longer internal electrodes; a plurality of shorter internal electrodes wherein the longer internal electrodes and the shorter internal electrodes have different lengths, are arranged so that the longer internal electrodes and the shorter internal electrodes extend from a pair of opposing side surfaces of the piezoelectric substrate towards the corresponding side surfaces of the piezoelectric substrate opposite to the side surfaces from which the longer internal electrodes and the shorter internal electrodes extend, and are arranged so that the shorter internal electrodes and the longer internal electrodes are alternately stacked inside the piezoelectric substrate; active portions disposed at locations where the longer internal electrodes and the corresponding shorter internal electrodes are stacked, the active portions being displaced in a direction that is substantially perpendicular to a direction in which the longer internal electrodes and the corresponding shorter internal electrodes are stacked; a first external electrode which is electrically connected to the shorter internal electrodes at one of the side surfaces of the piezoelectric substrate; and a second external electrode which is electrically connected to the longer internal electrodes at one of the side surfaces of the piezoelectric substrate; wherein the first external electrode and the second external electrode are separately disposed on a surface of the piezoelectric substrate; and the first external electrode extends from the side surface of the piezoelectric substrate near the active portions, extends onto a main surface of the piezoelectric substrate, and extends to a location adjacent to the side surface that is distant from the active portions where the longer internal electrodes are drawn out, and the second external electrode extends onto the main surface so as to be disposed on left and right sides of locations at the first external electrode that are adjacent to the side surface of the piezoelectric substrate that is distant from the active portions.