| 摘要 |
PROBLEM TO BE SOLVED: To improve the driving and detecting efficiency of an external force detecting sensor by forming a plurality of grooves on one surface of a piezoelectric supporting beam at regular intervals in the direction perpendicular to the axis of the beam in which electrodes are formed and alternately leading out lead-out electrodes from the electrodes in a comb-teeth shape. SOLUTION: A piezoelectric substrate 2 is stuck to a supporting substrate 1 having a hollow section 1a and a piezoelectric supporting beam 3 is formed in the hollow section 1a. Grooves 4 respectively provided with groove electrodes 4a are formed on the supporting beams 3 at regular intervals in the direction perpendicular to the axis of the beam 3. Then comb-shaped electrodes (k) are formed by alternately leading out lead-out electrodes in the opposite directions from the electrodes 4a and respectively connected to electrode pads 5c and 5d. When an AC voltage is applied across the pads 5c and 5d, the beam 3 makes flexural oscillations, because an electrode field is formed not only in the surface layer of the beam, but also in the beam 3. When the beam 3 bends, an electric field which passes through the surface layer and inside of the beam 3 is formed between the electrodes (k) and, as a result, a voltage is generated across the electrode pads 5c and 5d. Therefore, the driving and detecting efficiency of an external force detecting sensor can be improved. |
