NTC THERMISTOR AND CHIP TYPE NTC THERMISTOR

摘要

PURPOSE: An NTC(negative temperature coefficient) thermistor is provided to make fast responding speed in temperature sensing to lower resistance and to elevate reliability. CONSTITUTION: An alumina substrate is provided as an electricity insulating substrate(1). A thermistor film(2) is formed by sputtering a mold containing over 50wt% of LaCoO3 as an oxide of the rare-earth transit element containing La and Co by employing a high frequency sputtering device. The sputtering process is performed in the atmosphere of Ar, at 500°C of the substrate, 800W of high frequency electricity and 3 micrometer/H of film forming speed. Thermal treatment is performed for a time proper to the temperature selected from the 300-1000°C of temperature range. The crystallization of the thermistor film is improved and the film is stabilized. An electrode is formed on the substrate with the thermistor film. When the substrate is divided into respective device(4), the electrode becomes a pair of surface electrodes(3) facing each other. After obtaining the respective device, outer electrodes(5) are formed on both ends of the device to be electrically contacted to the surface electrodes correspondingly. The outer electrodes are formed continuously over a portion on the upper and the lower faces adjacent to the sides facing each other of the plane substrate. The surfaces of the thermistor film and the surface electrodes are coated with an electricity insulating glass coating agent(6). Thereby an NTC thermistor is obtained.