| 摘要 |
PURPOSE:To reduce spurious response by regularly changing the film thickness of respective electrodes formed on both the main surfaces of a piezo-electric substrate in the directions parallel to the diagonal directions of respective main surfaces. CONSTITUTION:Respective electrodes 6 are obtained by forming the 1st electrode films 7 having the uniform film thickness over the whole surfaces of respective main surfaces and forming the 2nd electrode films 8 on the electrode films 7. The electrode films 8 are stripe-like electrode films constituted of plural band parts 8a formed on the main surfaces of the piezo-electric substrate 5 with the same pitch in the parallel direction along the diagonal lines of respective surfaces and the band parts 8a are arrayed in the directions intersected with each other on the front and back surfaces of the piezo-electric element 2. When a voltage is applied to the electrodes 6, expanding vibration components along the diagonal lines are energized without any trouble in the surface directions of the substrate 5 and vibration components in the vertical thickness direction are dispersed by the discontinuous change of the film thickness of the electrodes 6, suppressing spurious response.
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