A semiconductor chip (1, 2, 3, 4, 5, 6), comprising: a functional area (11, 21, 31, 41, 51, 61), the functional area being a semiconductor material area having a first side (111, 211, 311, 411, 511, 611) and a second side (112, 212, 312, 412, 512, 612) which are opposite each other; a first end (12, 22, 32, 42, 52, 62), the first end being an output end disposed on the first side (111, 211, 311, 411, 511, 611); a second end, the second end being an output end; a third end (13, 23, 33, 43, 53, 63), the third end being an input end disposed on the first side (111, 211, 311, 411, 511, 611), wherein the semiconductor chip (1, 2, 3, 4, 5, 6) is switched on or off according to a drive signal received between the third end (13, 23, 33, 43, 53, 63) and the first end (12, 22, 32, 42, 52, 62); a connecting portion (14, 24, 34, 44, 54), being disposed on the first side (111, 211, 311, 411, 511, 611) of the functional area (11, 21, 31, 41, 51, 61) and being connected to the first end (12, 22, 32, 42, 52, 62) and the third end (13, 23, 33, 43, 53, 63), wherein when a temperature rises above a first temperature, the connecting portion is in a conductive state, so that the semiconductor chip (1, 2, 3, 4, 5, 6) is switched off due to a short circuit between the first end (12, 22, 32, 42, 52, 62) and the third end (13, 23, 33, 43, 53, 63); and when the temperature drops to be not higher than a third temperature, the connecting portion is in an insulating state, wherein the first temperature is higher than or equal to the third temperature; and a metal wiring layer characterized in that the first temperature is lower than a melting temperature of the metal wiring layer, and is lower than a lowest temperature at which the semiconductor chip loses semiconductor characteristics, wherein the semiconductor chip has semiconductor switching characteristics and the connection portion is in the insulating state when a temperature of the semiconductor chip is lowered to be no higher than a second temperature, wherein the second temperature is a maximum allowable junction temperature of the semiconductor chip, is lower than a limiting temperature that the semiconductor can withstand to remain the semiconductor switching characteristics and is lower than the first temperature. a functional area (11, 21, 31, 41, 51, 61), the functional area being a semiconductor material area having a first side (111, 211, 311, 411, 511, 611) and a second side (112, 212, 312, 412, 512, 612) which are opposite each other; a first end (12, 22, 32, 42, 52, 62), the first end being an output end disposed on the first side (111, 211, 311, 411, 511, 611); a second end, the second end being an output end; a third end (13, 23, 33, 43, 53, 63), the third end being an input end disposed on the first side (111, 211, 311, 411, 511, 611), wherein the semiconductor chip (1, 2, 3, 4, 5, 6) is switched on or off according to a drive signal received between the third end (13, 23, 33, 43, 53, 63) and the first end (12, 22, 32, 42, 52, 62); a connecting portion (14, 24, 34, 44, 54), being disposed on the first side (111, 211, 311, 411, 511, 611) of the functional area (11, 21, 31, 41, 51, 61) and being connected to the first end (12, 22, 32, 42, 52, 62) and the third end (13, 23, 33, 43, 53, 63), wherein when a temperature rises above a first temperature, the connecting portion is in a conductive state, so that the semiconductor chip (1, 2, 3, 4, 5, 6) is switched off due to a short circuit between the first end (12, 22, 32, 42, 52, 62) and the third end (13, 23, 33, 43, 53, 63); and when the temperature drops to be not higher than a third temperature, the connecting portion is in an insulating state, wherein the first temperature is higher than or equal to the third temperature; and a metal wiring layer characterized in that the first temperature is lower than a melting temperature of the metal wiring layer, and is lower than a lowest temperature at which the semiconductor chip loses semiconductor characteristics, wherein the semiconductor chip has semiconductor switching characteristics and the connection portion is in the insulating state when a temperature of the semiconductor chip is lowered to be no higher than a second temperature, wherein the second temperature is a maximum allowable junction temperature of the semiconductor chip, is lower than a limiting temperature that the semiconductor can withstand to remain the semiconductor switching characteristics and is lower than the first temperature.