Patent attributes
A protective element with improved spherical segmentation performance during the melting of a low-melting metal member, has a heat-generating member and a low-melting metal member on a substrate, in which the low-melting metal member is heated and blown out by the heat generated by the heat-generating member. There is a region in which the low-melting metal member is suspended over the underlying base (such as an insulating layer), and when S (μm2) is the surface area of a lateral cross section of the low-melting metal member 4 between a pair of low-melting metal member electrodes 3a and 3b or 3b and 3c sandwiching the region, and H (μm) is the height at which the suspended region is suspended, then the relationship H/S≧5×10−5 is satisfied. It is preferable here that the upper surfaces of both of the pair of low-melting metal member electrodes protrude beyond the upper surface of the underlying insulating layer.