PTC thermistor with improved flash pressure resistance

摘要

A PTC thermistor has a disk-shaped main body with electrodes on its main surfaces which are facing mutually away from each other such that, during an initial period after a potential difference is applied between these electrodes, the side surface of the main body has an asymmetric temperature distribution between the electrodes in the direction normal to its main surfaces. The heat emission does not have a peak half-way between the electrodes in the direction of the thickness such that the thermistor has an improved resistance against flash pressure. This may be done by forming the electrodes in different sizes or by providing a non-uniform distribution in specific resistance to the main body such that the heat-emission peak is displaced from the center region between the two main surfaces of the main body.