| 摘要 |
A technology capable of improving receiver sensitivity and improving insulation withstand voltage in an ultrasonic transducer is provided. An ultrasonic transducer comprises: a lower electrode 301; an insulator 302, 304, 305, 307, 309 covering the lower electrode 301; a cavity portion 303 disposed on the insulator so as to overlap with the lower electrode 301; and an upper electrode 306 disposed so as to overlap with the cavity portion 303. In this ultrasonic transducer, an insulator is inserted between the upper and lower electrodes 306, 301 in a part not having the cavity portion 303. By this means, sum total of thickness of insulators between the upper and lower electrodes 306, 301 in a part not having the cavity portion 303 is larger than sum total of thickness of insulators between the upper and lower electrodes 306, 301 in a part having the cavity portion 303. |
