Patent attributes
Electrode layers 22A-22C, 24A-24C are formed on both main surfaces of each of piezoelectric layers 20A, 20B. Voltages of different polarities are respectively applied to the electrode layers next to each other on the same main surface and to the electrode layers opposing to each other via the piezoelectric layer. Projection forms 30, 32 are formed in respective edges of the second electrode layers 22B, 24B, each of which extends into the opposite area. Through-holes are formed in the piezoelectric layer 20A, 20B, in positions off a division line 38. The electrode layers 22A-22C are connected together by the through-holes 26A, 26B and the projection form 30, to have an equal potential. Those are lead from the diaphragm to the outside, thus reducing the overall thickness.
