Thermistor element

Patent metadata

Field	Value
Publication number	US-10037838-B2
Application number	US-201715585216-A
Country	US
Kind code	B2
Filing date	May 3, 2017
Priority date	Nov 7, 2014
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

A thermistor element satisfies 4≤(d/ed) when a first distance is d, which is a shortest distance between a first internal electrode and a second external electrode, whereas a second distance is referred to as ed, which is a shortest distance between the first internal electrode and a fifth internal electrode, in a cross section of a body including an L direction and a T direction thereof.

First claim

What is claimed is:

1. A thermistor element comprising:
a body including a length direction, a width direction, and a height direction;

two external electrodes covering both ends of the body in the length direction; and
multiple internal electrodes laminated at intervals in a height direction in the body; wherein the multiple internal electrodes include:
an outermost internal electrode disposed outermost in the height direction and connected to one of the external electrodes; and
an adjacent internal electrode overlapping with the outermost internal electrode in the height direction and connected to the other external electrode;
the outermost internal electrode extends past a center or a substantial center of the body; and
in a cross section including the length direction and height direction of the body, a first distance that is a shortest distance between the outermost internal electrode and the other external electrode is denoted by d, and a second distance that is a shortest distance between the outermost internal electrode and the adjacent internal electrode is denoted by ed, the first and second distances satisfy 4≤(d/ed)≤10.

2. The thermistor element according to claim 1 , wherein
when a minimum thickness of the body is denoted by Tm between a surface of the body and an internal electrode located closest to the surface, among the multiple internal electrodes, in the height direction; and
when a minimum thickness of the body is denoted by Wm between a surface of the body and an internal electrode located closest to the surface, among the multiple internal electrodes, in the width direction;
the minimum thicknesses satisfy 0<(Tm/Wm)≤0.4.

3. The thermistor element according to claim 1 , wherein a number of the internal electrodes connected to the one of the external electrodes and a number of the internal electrodes connected to the other external electrode are odd numbers.

4. The thermistor element according to claim 1 , wherein a number of the internal electrodes connected to the one of the external electrodes and a number of the internal electrodes connected to the other external electrode are even numbers.

5. The thermistor element according to claim 1 , wherein the body includes multiple ceramic layers laminated together to define an integral structure.

6. The thermistor element according to claim 5 , wherein the ceramic layers are composed of a ceramic that has negative resistance-temperature characteristics.

7. The thermistor element according to claim 6 , wherein the ceramic contains a manganese oxide as a main constituent, and includes at least one of a nickel oxide, a cobalt oxide, alumina, an iron oxide, a titanium oxide, and a zirconium oxide.

8. The thermistor element according to claim 1 , wherein the external electrodes each include an electrode layer covering the body, and a plated layer laminated on the electrode layer.

9. The thermistor element according to claim 8 , wherein the electrode layer is made of Ag, and the plated layer is made of Sn or Cu.

10. The thermistor element according to claim 1 , wherein the multiple internal electrodes include at least one element of Ag, Pd, and Cu.

11. The thermistor element according to claim 1 , wherein
the multiple internal electrodes include first, second, and third internal electrodes arranged in order in the height direction and connected to the one of the external electrodes, and fourth, fifth, and sixth internal electrodes arranged in order in the height direction and connect to the other external electrode; and
the outermost internal electrode is the first internal electrode and the adjacent internal electrode is the fifth internal electrode.

12. The thermistor element according to claim 11 , wherein the first internal electrode and the fourth internal electrode are located on a same level in the height direction, the second internal electrode and the fifth internal electrode are located on a same level in the height direction, and the third internal electrode and the sixth internal electrode are located on a same level in the height direction.

13. The thermistor element according to claim 1 , wherein the first and second distances satisfy 5≤(d/ed)≤10.

14. The thermistor element according to claim 1 , wherein the first and second distances satisfy 6≤(d/ed)≤10.

Assignees

• Murata Manufacturing Co

Inventors

• Nawai Shinichiro
• Hirata Yuichi

Classifications

• H01C1/148

  the terminals embracing or surrounding the resistive element (H01C1/142 takes precedence) · CPC title

• H01C7/04 Primary

  having negative temperature coefficient · CPC title

• H01C1/1413

  Terminals or electrodes formed on resistive elements having negative temperature coefficient · CPC title

• H01C7/041

  formed with two or more layers · CPC title