Patent ID: 7564985

Claim:
A condenser microphone comprising a substrate which is accommodated in a cylindrical metal capsule having a sound collecting hole at one end and on which a diaphragm, a rear pole, a holder, and an impedance converting circuit are mounted, the cylindrical capsule having the other end caulked to an outer surface of the substrate so as to form a caulking portion, thus fixing internal parts, wherein the substrate comprises: an annular metal plate; a substrate main body comprising an insulating material and including a flat plate portion covering an entire surface of the annular metal plate located opposite a mounted side and a central projecting portion connected to the flat plate portion through an interior of the annular metal plate to project an outer peripheral surface of the mounted side of the annular metal plate; an external ground terminal formed in an outer peripheral portion of a flat surface of a mounted side of the central projecting portion and connected to the annular metal plate through an outer surface or a through-hole and an external signal output terminal formed in a central portion of the central projecting portion away from the external ground terminal; an internal ground terminal formed on a flat surface of the flat plate portion located opposite a mounted side and connected to the annular metal plate through a through-hole, an internal signal output terminal formed in a central portion of the flat plate portion away from the other terminals and connected to the external signal output terminal through a through-hole, and an input terminal formed away from the internal terminals and connected to an input side of the circuit.