| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-size, highly reliable, and high performance electret capacitor which shows excellent moisture-proof characteristic and includes an electret formed of silicon oxide film. SOLUTION: The electret capacitor comprises a first electrode 11 in which an empty hole 10 is formed, an air gap 15 connected to the empty hole, and a second electrode 16. The electret film formed of silicon oxide film 4 is formed to the first electrode, and the air gap 15 and electret are formed between the first electrode and the second electrode. In the electret film, an insulating film is formed to the upper surface and lower surface of the silicon oxide film and the second electrode operates as an vibrating film. COPYRIGHT: (C)2005,JPO&NCIPI
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