摘要 |
An electret capacitor microphone, comprising a diaphragm (33) and a rear electrode (35) forming a capacitor, a cylindrical case (31) in which the diaphragm (33) and the rear electrode (35) are stored, a circuit board (39) stored in the cylindrical case (31) on the opening part (31c) side, and fixed to the opening part (31c) by caulking a caulking part (31b) formed by bending the opening edge of the cylindrical case (31) to the inside to close the opening part (31c), and a substrate (51) fixed to the outer surface of the circuit board (39). A circular pattern (44) and an annular pattern (45) are formed on the outer surface of the circuit board (39), and a circular pattern (52) and an annular pattern (53) are formed on the surface of the substrate (51) on the opposite side of the circuit board (39) side. The circuit pattern (44) and the annular pattern (45) are electrically connected to the circular pattern (52) and the annular pattern (53) through through-holes (54a) and (54b) formed in the substrate (51), and the surface of the substrate (51) on which the circular pattern (52) and the annular pattern (53) are formed is formed in a reflow soldering face. |