PTC ELEMENT

摘要

PURPOSE:To prevent increase in resistance value of a PTC element by preventing peeling of an electrode off a PTC element body when temperature change in the PTC element repeatedly takes place according to applied voltages. CONSTITUTION:A PTC element body 1 is constituted by a positive temperature coefficient organic composition in which conductive particles are dispersed into a polymer material. A combined body which is formed by forming a conductive layer 5 by coating a metal foil 4 with a conductive paste which is prepared by blending a metal particle with a binder is referred to an electrode 2. With the conductive layer 5 facing the PTC element body 1, and also with the metal foil 4 kept not to touch the PTC element body 1, the electrode 2 is compression- bonded to the PTC element body 1 so that a PTC element 3 is formed. The thermal expansion coefficient of the conductive layer 5 during the period until reaching the trip temperature in the PTC element 3 is set to be an intermediate value between the thermal expansion coefficient of the metal foil 4 and that of the PTC element body 1.