| 摘要 |
A vibration electrode plate (34), which performs film vibration upon receiving vibration, is arranged on an upper surface of a silicon substrate (32) including a hollow portion (37). A fixed electrode plate (36) in which a plurality of acoustic perforations (43) passing therethrough in the thickness direction is opened is arranged on an upper side of the vibration electrode plate (34), and the vibration electrode plate (34) and the fixed electrode plate (36) are faced to each other. A vent hole (45) for communicating an air gap (35), which is between the vibration electrode plate (34) and the fixed electrode plate (36), to the hollow portion (37) is arranged between the upper surface of the silicon substrate (32) and the lower surface of the vibration electrode plate (34) at the periphery of the hollow portion (37). An air escape portion (42) in the form of a plurality of through-holes is opened in the vibration electrode plate (34) in the region corresponding to the vent hole (45). |
