Patent ID: 7304562

Claim:
A process for producing an organic PTC thermistor comprising the steps of: mixing an organic binder with a filler to obtain a mixture; layer-forming on a first conductive foil, a mixture layer comprising the mixture to obtain a laminate; and laminating on the laminate, a second conductive foil or another of the laminate to obtain a sandwich so that the mixture layer can be sandwiched by the opposing conductive foils, wherein at least one of the mixing step, the layer-forming step and the laminating step is conducted under reduced pressure, wherein the at least one of the mixing step, the layer-forming step and the laminating step is conducted under reduced pressure to remove voids from the mixture layer so that the following equations (1) and (2) can be satisfied: A≧100 Eq. (1) B/A ≧0.5 Eq. (2) wherein A and B each represent the change rate of resistance to be calculated according to the following equation (3) or (4): A =( Ra 1 /Ra 0 )×100 Eq. (3) B =( Rb 1 /Rb 0 )×100 Eq. (4) wherein each of Ra 0 , Ra 1 , Rb 0 and Rb 1 is an electric resistance value of the organic PTC thermistor; Ra 0 represents a value at 25° C. before heating at 260° C.; Ra 1 represents a value at 185° C. before heating at 260° C.; Rb 0 represents a value at 25° C. after heating at 260° C.; and Rb 1 represents a value at 185° C. after heating at 260° C.