Semiconductor ceramic composition for NTC thermistors and NTC thermistor
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.
1. A semiconductor ceramic composition for NTC thermistors, consisting essentially of Mn, Ni, and Fe, wherein
the molar amounts 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.
2. The semiconductor ceramic composition for NTC thermistors according to claim 1 , additionally containing Co 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.
3. The semiconductor ceramic composition for NTC thermistors according to claim 2 , in which the Co is in an amount of at least 4 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
4. The semiconductor ceramic composition for NTC thermistors according to claim 3 , in which the Mn is in an amount of 70 to 75 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
5. The semiconductor ceramic composition for NTC thermistors according to claim 4 , in which the Fe is in an amount of 15 to 20 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
6. The semiconductor ceramic composition for NTC thermistors according to claim 1 , in which the Mn is in an amount of 70 to 75 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
7. The semiconductor ceramic composition for NTC thermistors according to claim 6 , in which the Fe is in an amount of 15 to 20 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
8. The semiconductor ceramic composition for NTC thermistors according to claim 7 , additionally containing Co in an amount of 4 parts by mole to 40 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
9. The semiconductor ceramic composition for NTC thermistors according to claim 1 , in which the Fe is in an amount of 15 to 20 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
10. The semiconductor ceramic composition for NTC thermistors according to claim 9 , additionally containing Co in an amount of at least 4 parts by mole relative to the total molar amount (100 parts by mole) of Mn and Ni.
11. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 10 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
12. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 9 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
13. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 8 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
14. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 7 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
15. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 6 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
16. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 5 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
17. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 4 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
18. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 3 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
19. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 2 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
20. An NTC thermistor comprising a component main body of the semiconductor ceramic composition according to claim 1 , and first and second electrodes facing each other with at least a portion of the component main body therebetween.
21. A semiconductor ceramic composition for NTC thermistors, comprising Mn, Ni, and Fe, wherein
the molar amounts 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,
wherein said composition is free of Al and Ti.