| 摘要 |
PURPOSE:To ensure 'OFF' state of a fuse circuit by providing a gap on which a threaded defective pattern is formed, on a wiring pattern on the surface of an insulator, and by welding a low temperature fusible alloy to the gap position, so as to connect a wiring pattern and to obtain a fuse thereby. CONSTITUTION:A heating element 1 is composed of a base material 2 and a wiring pattern 3 formed on the surface of the base material 2, and the wiring pattern 3 is formed out of a heating resistor pattern 3A and a conductor pattern 3B. A gap 4 is provided on a part of the conductor pattern 3B. The part of the conductor pattern 3B is notched in a certain size, and the base material 2 in the part is exposed thereby, and the gap 4 is thus formed, while an insulating pattern 5 composed of a wetting defect is formed on the surface of the base material 2 in such a way that the gap 4 is filled, and a fuse part 7 is formed by welding a solder 6 of low melting point in such a way that a bridge is formed on the edge of the conductor pattern 3B that is opposed over the gap 4. When the fuse part 7 is overheated to a preset temperature, the solder 6 is melted and is attracted to the end part of the conductor pattern 3B, and the circuit is turned 'OFF' thereby. |
