| 摘要 |
A phenomenon in which a bonding agent (56) that fixes an acoustic sensing element (32, 62, 72 to 82) to a base substrate (34) runs to through a back chamber (45) is prevented. A leakage of a back chamber (45) from a lower surface of the acoustic sensing element (32, 62, 72 to 82) is prevented. A deformation of the acoustic sensing element (32, 62, 72 to 82) is decreased to improve sensitivity of an acoustic sensor (31 , 61, 68, 71). A lower surface of the acoustic sensing element (32, 62, 72 to 82) is bonded to an upper surface of the base substrate (34) by the thermosetting bonding agent (56). In the acoustic sensing element (32, 62, 72 to 82), a vibration electrode plate (43) and a fixed electrode plate (44) that is opposite the vibration electrode plate (43) are prepared on an upper surface of an element substrate (41). The back chamber (45) is formed in the element substrate (41). The back chamber (45) is opened to the upper surface of the element substrate (41), and a lower surface of the back chamber (45) is closed into a pouched shape by the element substrate (41). The vibration electrode plate (43) is located in the upper surface opening of the back chamber (45), and an acoustic hole (55) is made in the fixed electrode plate (44) in order to pass an acoustic vibration.
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