| 摘要 |
PURPOSE:To improve the heat conductivity and to suppress a rise in thermal deformation temperature by molding a coil bobbin used for an acoustic transducer such as a speaker and a microphone by using an aromatic polyimide resin film to which powder of boron nitride is added. CONSTITUTION:This coil bobbin, formed of an aromatic polyimide resin film to which powder of boron nitride is added, has excellent heat conductivity and high thermal deformation temperature, prevents the generation of an eddy current, and suits, specially, to a large-input acoustic transducer. For example, powder of 3wt% boron nitride is added to aromatic polyimide resin, which is molded into a film; and the film is cut in a specific shape and assembled into a cylindrical bobbin, which is wound with a voice coil. This coil bobbin 1 has improve heat conductivity, so Joule heat generated at the voice coil is conducted excellently and radiated from the coil bobbin and other members, so a rise in voice coil temperature is small with the same input electric power, thereby improving the input resistance characteristic of the acoustic transducer. |
