| 摘要 |
PROBLEM TO BE SOLVED: To provide a condenser microphone capable of simplifying its manufacturing process, and to provide its manufacturing method. SOLUTION: A sound sensor of a condenser microphone 1 has a laminated construction composed of a device board 10 and a first film to a fourth film. A hole 11 at the device board 10 has a cylindrical shape and opens to a first plane 10a and a second plane 10b. A concave 12 of the device board 10 has the shape of a groove, opens to the second plane 10b, and extends to outside in the radial direction from the hole 11. As a result, an aperture 13 having the shape of a gear and composed of a circular aperture 13a and a rectangular aperture 13b is formed on the second plane 10b of the device board 10. The rectangular aperture 13b extends to outside in the radial direction from a part of the outer rim of the aperture 13a. On the other hand, a circular aperture 14 according to the two dimensional shape of a diaphragm 20 is formed on the first plane 10a of the device board 10. Even if air bubbles generate and cover the aperture 13 in wet etching process, the generated air bubbles tend to burst, because surface tension force acting on the air bubbles becomes uneven by the aperture 13b. COPYRIGHT: (C)2008,JPO&INPIT
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