| 摘要 |
<p>The present invention relates to a condenser microphone wherein a spacer is eliminated by forming a concaved portion at a center portion of a back electret. The condenser microphone in accordance with the present invention comprises a cylinder-shape metal casing having an acoustic hole through a front plate thereof; polar ring consisting of a conductor; a diaphragm; a ring-shape first base consisting of an insulating material; a back electret consisting of a metal plate having a high molecule film coated thereon, the back electret having an edge portion contacting the diaphragm, wherein a surface of the high molecule film opposing that of the diaphragm includes a concaved surface deepening away from the edge portion to a center portion thereof; a second base consisting of a conductor; and a PCB having a circuit component mounted thereon and a connection terminal formed thereon. Therefore, in accordance with the present invention, a center portion of a back electret is subjected to a series of processes such as a pressing to render a surface of a high molecular film of the back electret opposing a diaphragm into a concaved surface similar to a vibrating form of the diaphragm so that a conversion of a displacement of the diaphragm to an electrical signal is maximized to improve a sensitivity and that the spacer for forming an insulation space is eliminated to reduce the number of components and the manufacturing cost.</p> |
