| 摘要 |
PROBLEM TO BE SOLVED: To prevent the oxidation of a surface at heating/melting time, and provide a reliably actuating and highly reliable fuse by covering the surface of the fuse with a high melting point covering member. SOLUTION: A resistance pattern formed of a resistor is sandwiched by a heat radiating plate via an insulator, and a resistor is constituted, and a fuse 4 composed of solder melting at a temperature not less than a prescribed value is provided. The entire surface of the fuse 4 is covered by plating gold 10 having a melting temperature higher than the solder and a melting point of 1,064 deg.C in a thickness of 0.25μm to 10μm. An overcurrent flows to the fuse 4 by some accident, and a temperature rises, and even if the solder starts to melt, an oxide film is not formed on a surface of the fuse 4 by a gold film. When it is disconnected since the solder melts, the gold film is also deformed and is disrupted, and is taken into the molten solder, and the gold 10 is also integrally solidified according to the solidification of the solder. Therefore, the molten fuse 4 can be supply fused without reducing laterally separating force by an oxide film.
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