| 摘要 |
PURPOSE:To decrease the radius of a diaphragm and to lower basic resonance frequency by using a metallic plate as a ring forming material for diaphragm extension, providing a conductive thin-film layer over one surface of this metallic plate, and etching the metallic plate into the shape of the diaphragm extension ring. CONSTITUTION:The metallic plate 41 for the formation of the diaphragm extension ring and composite conductive film 31 are laminated. The film 31 has internal stress owing to the vaporization of an organic solvent and the cohesive force of a polymer itself, but the polymer having high adhesive strength to the metallic plate for the diaphragm extension ring forming material is used to maintain the shape. Then, the metallic surface side of the metallic plate 41 is coated with photoresist and the forming material for the diaphragm extension ring is etched into the shape of the diaphragm extension ring, thus obtaining title diaphragm for the capacitor type microphone. |
