Patent ID: 6912288
Filing Date: 2005-06-28
Classification: H04R

Abstract:
1. A piezoelectric electroacoustic transducer comprising: a plurality of piezoelectric ceramic layers deposited so as to define a deposited product having top and bottom major surfaces; external electrodes disposed on the top and bottom major surfaces of the deposited product; internal electrodes disposed between adjacent ones of the plurality of piezoelectric ceramic layers; and dummy electrodes disposed between adjacent ones of the plurality of piezoelectric ceramic layers and outside the internal electrodes via a gap; wherein all of the plurality of piezoelectric ceramic layers are polarized in the same direction of thickness of the deposited product and the piezoelectric electroacoustic transducer flexurally vibrates in response to application of an alternating signal applied between the external electrodes and the internal electrodes, portions of the internal electrodes are exposed at at least a first side surface of the piezoelectric ceramic layers, the dummy electrodes are exposed at a second side surface of the piezoelectric ceramic layers, and the external electrodes extend only to side surfaces other than the first side surface at which the internal electrodes are exposed; trimmed portions of the external electrodes are disposed at positions corresponding to the side surface of the piezoelectric ceramic layers at which the internal electrodes are exposed; extension electrodes are disposed at the positions in which the trimmed portions of the external electrodes are disposed, and side surface electrodes are disposed on side surfaces of the piezoelectric ceramic layers; and the extension electrodes are connected to the internal electrodes via the side surface electrodes.