Protective element and protective circuit substrate using the same

A protective circuit substrate having a circuit substrate and a protective element mounted on the circuit substrate,

• the protective element comprising:
• a rectangurarly shaped insulating substrate;
• a heat-generating element formed on the insulating substrate;
• an insulating member laminated on the insulating substrate for so as to cover at least the heat-generating element;
• a first and a second electrodes laminated on a surface of the insulating substrate;
• a first connecting terminal provided on a back surface of the insulating substrate and being continuous with the first electrode and a second connecting terminal provided on the back surface and being continuous with the second electrode;
• a heat-generating element extracting electrode provided on a current path between the first and the second electrodes and electrically connected to the heat-generating element;
• and
• a meltable conductor laminated on a region extending from the heat-generating element extracting electrode to the first and second electrodes and to be melted by heat to interrupt the current path between the first electrode and the second electrode;
• wherein at least one of the corner portions of the insulating substrate is chamfered.