Thermistor sintered body and thermistor element

Patent metadata

Field	Value
Publication number	US-10643768-B2
Application number	US-201816475944-A
Country	US
Kind code	B2
Filing date	Apr 27, 2018
Priority date	Jun 20, 2017
Publication date	May 5, 2020
Grant date	May 5, 2020

Abstract

A thermistor sintered body that can control a B constant at 1000° C. to the same level as that of a conventional wide range type. The thermistor sintered body according to the present invention has a composite structure that includes a Y2O3 phase and a Y(Cr, Mn)O3 phase or a YMnO3 phase. In the thermistor sintered body according to one aspect of the present invention, a chemical composition of Cr, Mn, Ca and Y excluding oxygen is Cr: 3 to 9 mol %, Mn: 5 to 15 mol %, Ca: 1 to 8 mol % (where Cr/Mn<1.0), and the balance being unavoidable impurities and Y. In the thermistor sintered body, the B constant (B(0/1000)) determined by the following Expression (1) is 2400 K or lower; B=(lnRm−lnRn)/(1/Tm−1/Tn) . . . (1). Rm: resistance value at 0° C., Rn: resistance value at 1000° C., Tm: 0° C., and Tn: 1000° C.

First claim

The invention claimed is:

1. A thermistor sintered body comprising a sintered body that comprises a Y 2 O 3 phase and a Y(Cr, Mn)O 3 phase or a YMnO 3 phase, and is rich in Mn relative to Cr, wherein
a B constant (B(0/1000)) determined by the following expression is 2400 K or lower;
B=(lnRm−lnRn)/(1/Tm−1/Tn), wherein
Rm: resistance value at 0° C.,
Rn: resistance value at 1000° C.,
Tm: 0° C., and
Tn: 1000° C.

2. The thermistor sintered body according to claim 1 , wherein
the sintered body comprises the Y 2 O 3 phase and the Y(Cr, Mn)O 3 phase; and
a chemical composition of Cr, Mn, Ca and Y excluding oxygen is Cr: 3 to 9 mol %, Mn: 5 to 15 mol %, Ca: 1 to 8 mol % (wherein Cr/Mn<1.0), and the balance being unavoidable impurities and Y, wherein
Cr/Mn is 0.4 to 0.9.

3. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 2 .

4. The thermistor sintered body according to claim 1 , wherein
Ca dissolves in the Y(Cr, Mn)O 3 phase or in the YMnO 3 phase.

5. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 4 .

6. The thermistor sintered body according to claim 1 , comprising a crystal structure of an orthorhombic crystal system.

7. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 6 .

8. The thermistor sintered body according to claim 1 , wherein
a B constant (B(−40/25)) determined by the following expression is 2200 K or lower;
B=(lnRm−lnRn)/(1/Tm−1/Tn), wherein
Rm: resistance value at −40° C.,
Rn: resistance value at 25° C.,
Tm: −40° C., and
Tn: 25° C.

9. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 8 .

10. The thermistor sintered body according to claim 1 , wherein
a B constant (B(25/600)) determined by the following expression is 2300 K or lower;
B=(lnRm−lnRn)/(1/Tm−1/Tn), wherein
Rm: resistance value at 25° C.,
Rn: resistance value at 600° C.,
Tm: 25° C., and
Tn: 600° C.

11. The thermistor sintered body according to claim 1 , wherein
a B constant (B(600/1000)) determined by the following expression is 2800 K or lower;
B=(lnRm−lnRn)/(1/Tm−1/Tn), wherein
Rm: resistance value at 600° C.,
Rn: resistance value at 1000° C.,
Tm: 600° C., and
Tn: 1000° C.

12. The thermistor sintered body according to claim 1 , wherein
a resistance value at 1050° C. is 0.05 kΩ or larger.

13. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 12 .

14. The thermistor sintered body according to claim 1 , wherein
a resistance value of 100 kΩ is exhibited at room temperature or lower.

15. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 14 .

16. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 1 .

17. A thermistor sintered body comprising a sintered body that comprises a Y 2 O 3 phase and a Y(Cr, Mn)O 3 phase, and is rich in Mn relative to Cr, wherein
a B constant (B(0/1000)) determined by the following expression is 2400 K or lower;
B=(lnRm−lnRn)/(1/Tm−1/Tn), wherein
Rm: resistance value at 0° C.,
Rn: resistance value at 1000° C.,
Tm: 0° C., and
Tn: 1000° C., wherein
a chemical composition of Cr, Mn, Ca and Y excluding oxygen is Cr: ≤mol % (excluding 0), Mn: 12 to 23 mol %, Ca: 6 to 18 mol %, and the balance being unavoidable impurities and Y, and wherein
Cr/Mn is 0.5 or smaller (excluding 0).

18. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 17 .

19. A thermistor sintered body comprising a sintered body that comprises a Y 2 O 3 phase and a YMnO 3 phase, and is rich in Mn relative to Cr, wherein
a B constant (B(0/1000)) determined by the following expression is 2400 K or lower;
B=(lnRm−lnRn)/(1/Tm−1/Tn), wherein
Rm: resistance value at 0° C.,
Rn: resistance value at 1000° C.,
Tm: 0° C., and
Tn: 1000° C., and wherein
a chemical composition of Mn, Ca and Y excluding oxygen is Mn: 12 to 18 mol %, Ca: 6 to 18 mol %, and the balance being unavoidable impurities and Y.

20. A thermistor element comprising:
a heat sensitive body;
a pair of lead wires electrically connected to the heat sensitive body; and
a covering layer covering the heat sensitive body, wherein
the heat sensitive body comprises the thermistor sintered body according to claim 19 .

Assignees

• Shibaura Electronics Co Ltd

Inventors

• Takeuchi Akitaka
• Niizeki Naohiro

Classifications

• C04B35/505

  based on yttrium oxide · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title

• C04B2235/3263

  Mn3O4 · CPC title

• C04B2235/6567

  Treatment time · CPC title

• H01C17/06533

  composed of oxides · CPC title