Surface-mountable negative-characteristic ceramic thermistor based on Mn, Co, Ni and Ti compounds

摘要

There is provided a high-reliability surface-mountable negative-characteristic thermistor having high strength of a ceramic body, the thermistor being capable of preventing the erosion of the ceramic body due to a plating solution without the need for the formation of a glass layer. A surface-mountable negative-characteristic thermistor 1 includes a ceramic body 4 composed of a semiconductor ceramic material containing at least one of Mn, Ni, and Ti; external electrodes 5 disposed on surfaces of the ceramic body 4; and plating films 6 disposed on surfaces of the external electrodes 5, wherein when the molar quantity of Mn in the semiconductor ceramic material is represented by a and when the molar quantity of Ni in the semiconductor ceramic material is represented by b, the molar ratio of Mn to Ni is in the range of 55/45 ‰ a/b ‰ 90/10, and wherein when the total molar quantity of Mn and Ni in the semiconductor ceramic material is defined as 100 parts by mole, the content of Ti is in the range of 0.5 parts by mole to 25 parts by mole.