POSITIVE TEMPERATURE-COEFFICIENT THERMISTOR

摘要

The present invention lowers the resistance of a positive temperature-coefficient thermistor having an embodiment wherein a thermistor thick film that is a heat source is formed on an alumina substrate. The positive temperature-coefficient thermistor (1) is provided with: an alumina substrate (2); a thermistor thick film (3) exhibiting PTC characteristics and formed on the alumina substrate (2); and a pair of electrodes (4, 5) that face each other sandwiching at least a portion of the thermistor thick film (3). The thermistor thick film (3) comprises a sintered body of a semiconductor ceramic having barium titanate as the primary component, and when the total donor quantity contained in the sintered body as a donor/Ti atom ratio is x, the amount of Mn as an Mn/Ti atom ratio is y, and the amount of Na in the alumina substrate (2) as an Na/Al atom ratio is z, the conditions 0.0008 = (x-0.5y-0.5z) = 0.004, 0 = y = 0.007, and 0 < z = 0.002 are satisfied.