A semiconductor chip , comprising: a functional area , the functional area being a semiconductor material area having a first side and a second side which are opposite each other; a first end , the first end being an output end disposed on the first side ; a second end, the second end being an output end ; a third end , the third end being an input end disposed on the first side , wherein the semiconductor chip is switched on or off according to a drive signal received between the third end and the first end ; a connecting portion , being disposed on the first side of the functional area and being connected to the first end and the third end , wherein when a temperature rises above a first temperature, the connecting portion is in a conductive state, so that the semiconductor chip is switched off due to a short circuit between the first end and the third end ; 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 , the functional area being a semiconductor material area having a first side and a second side which are opposite each other; a first end , the first end being an output end disposed on the first side ; a second end, the second end being an output end ; a third end , the third end being an input end disposed on the first side , wherein the semiconductor chip is switched on or off according to a drive signal received between the third end and the first end ; a connecting portion , being disposed on the first side of the functional area and being connected to the first end and the third end , wherein when a temperature rises above a first temperature, the connecting portion is in a conductive state, so that the semiconductor chip is switched off due to a short circuit between the first end and the third end ; 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. <EOS>