Patent ID: 7173512

Claim:
A thermistor which is to be attached to a surface of an object by welding in order to protect the object from overheating or excess current, the thermistor comprising: a resistance material layer of a sheet shape, of which electric resistance is changed depending on temperature; first and second electrodes respectively formed on both sides of the sheet-shaped resistance material layer; and first and second leads respectively formed on the first and second electrodes, wherein the second lead is made of an alloy having different main materials, wherein a part of the second lead to be united to the second electrode is mainly made of the same material as the second electrode, wherein a part of the second lead to be united to a surface of the object is mainly made of the same material as the surface of the object, and wherein the second lead is formed with a single layer and a composition ratio of the second lead is continuously changed along a thickness direction thereof.