HYBRID SUBSTRATE FUSE ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a fuse that can intercept short-circuit current with no abnormality under a trouble and also intercept overcurrent exceeding rating current, whereby a DC system can be surely protected.SOLUTION: A hybrid substrate fuse element 1 comprises a conductive thin film 3 formed on a ceramic substrate 2 having an electrical insulation property. The conductive thin film 3 is configured so that a large current intercepting part (P part) 4 and a small current intercepting part (I part) 5 are connected to each other in series through an electrical conduction part 6. Thirty two narrow parts 4a which are reduced in cross-sectional area are arranged electrically in parallel in the P part 4 to form a parallel intercepting part 4b. Ten parallel intercepting parts 4b are further arranged electrically in series through heat radiating parts 4c in the P part 4. An I part 5 is formed like a sheet, and a slender minimum cross-sectional area part 5a is formed in the I part 5. Ahead of the P part 4, the I part 5 intercepts overcurrent which is smaller than fault current to be intercepted by the P part 4 and larger than rating current.