| 摘要 |
PURPOSE:To decrease relatively the vibrating frequency and to attain ease of trimming by forming a slot in a direction crossing with a side contributing to the vibration and a spread vibration mode. CONSTITUTION:A mechanical vibration part 3 made of a constant elastic metallic plate such as elinvar, a coupling part 4 and a frame 5 are formed incorporatedly. Then a piezoelectric thin film 6 is provided and an electrode film 7 is provided on the film 6. Through the structure above, the vibrating mode decided by the size in the short side direction. The slot 8 is prolonged in a direction in crossing with the applied vibrating direction, preferably orthogonal thereto. If one slot is not enough, slots are preferably provided at both sides of the center slot symmetrically from the standpoint of balance. Laser trimming is applied to the formation of slots. Thus, the effective length on the surface is made longer in comparison with the case without slot to slow down the vibration propagating speed thereby decreasing the vibrating frequency.
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