Murata Manufacturing Co., Ltd.

Michiru Mikami

Hiroshi Marusawa

Yasunori Hioki

A temperature sensor that includes a first electrode layer, a second electrode layer, and a thermistor layer between the first and second electrode layers. The thermistor layer includes a spinel-type semiconductor ceramic composition powder containing Mn, Ni, and Fe, and an organic polymer component. In the semiconductor ceramic composition powder, the molar ratio of Mn to Ni is 85/15&#x2265;Mn/Ni&#x2265;65/35, and when the total molar quantity of Mn and Ni is 100 parts by mole, the content of Fe is 30 parts by mole or less, and the semiconductor ceramic composition powder is 2 &#x3bc;m or less in particle size.

Temperature sensor

Disclosed is a semiconductor ceramic composition for NTC thermistors, which has low dependency on firing temperatures, reduced variations in the resistance values after a resistance-adjusting operation, and reduced changes in resistance in high-temperature environments. The semiconductor ceramic composition contains Mn, Ni and Fe, wherein the molar ratios of Mn and Ni are in ranges of 70 to 80 mol % and 20 to 30 mol %, respectively, relative to the total content (100 mol %) of Mn and Ni, and the Fe content is in a range of 15 parts by mole to 25 parts by mole, both inclusive, relative to the total molar amount (100 parts by mole) of Mn and Ni. Preferably, Co is additionally present in an amount of 2 parts by mole to 40 parts by mole, both inclusive, relative to the total molar amount (100 parts by mole) of Mn and Ni.

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Nagaokakyo, Japan

Michiru Mikami