| 摘要 |
PURPOSE:To change easily the center frequency of oscillation and reduce the impedance fall even if higher-mode oscillation is used, by forming parts, which are displaced in directions opposite to each other, alternately in parallel with the surface in piezoelectric ceramics to generate bulk waves in the direction parallel with the surface of piezoelectric ceramics. CONSTITUTION:Electrodes 21a and 21b for polarization are formed on the longer side face of a layer-built structure body. Electrodes 21a and 21b for polarization are formed in parts where electrodes constituting individual electrode groups 11-15 are led out to the longer side of ceramic layers 1 and 2. Next, electrodes 21a and 21b for polarization are eliminated by cutting or grinding, and external electrodes 24 and 25 are formed on shorter side faces 22 and 23. The external electrode 24 is connected to electrodes 11a, 13a, and 15a in end parts of electrode groups 11, 13, and 15, and the other external electrode 25 is connected to electrodes 12b and 14d placed in end parts of electrode groups 12 and 14. |
