MANUFACTURING METHOD FOR VIBRATION FILM FOR ELECTROSTATIC TYPE ELECTROACOUSTIC TRANSDUCER ELEMENT, THE VIBRATING FILM AND ELECTROSTATIC TYPE ELECTROACOUSTIC TRANSDUCER ELEMENT PROVIDED WITH THE VIBRATION FILM

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method for a vibrating film for an electrostatic type electroacoustic transducer element with high productivity where the vibrating film with excellent heat resistance is formed at once with an electret material film and to provide the vibrating film and the electrostatic type electroacoustic transducer element provided with the vibrating film. SOLUTION: A nickel thin film 12 is formed to one side of a metallic material base 11, an electret material coating film 31 is formed on the surface of the nickel thin film 12, a partial region 131 on the other side of the metallic material base 11 is removed by etching to expose the nickel thin film 12, a vibration film ring 15 is joined to the exposed nickel thin film 12, and the metallic material base 11 is punched along the outer circumferential face of the vibration film ring 15 in the manufacturing method of the vibration film for the electrostatic type electroacoustic transducer element.