US Patent 7164341 Surface-mountable PTC thermistor and mounting method thereof

A surface-mountable PTC thermistor element includes electrodes disposed on a top surface and a bottom surface of a thermistor element body, in which each of the electrodes is connected with a terminal respectively and each of the terminals is extended downward. An upper terminal is protected from being detached by a reaction force acting against pressing at the time of press-mounting the PTC thermistor element onto a surface of a substrate. A vertical-leg portion of the lower terminal is placed inside the thermistor element body in the radial direction from the outer edge of the thermistor element body. Preferably, the vertical-leg portion of the lower terminal is placed in the vicinity of the center of the thermistor element body.