Ceramic heat-sensitive device

Abstract

A ceramic thermistor includes a ceramic body, an internal electrode layer, an interconnect structure, and an encapsulation layer. The internal electrode layer has a first internal electrode layer and a second internal electrode layer covering the upper and lower surfaces of the ceramic body, respectively. The interconnect structure has a first interconnect structure and a second interconnect structure connecting the first and second internal electrode layers, respectively, and extending below the second internal electrode layer. The encapsulation layer covers the ceramic body, the internal electrode layer, and the interconnect structure, such that a portion of the first interconnect structure and a portion of the second interconnect structure are located below the encapsulation layer.

Claims

1. A ceramic thermistor, comprising: a ceramic body having an upper surface and a lower surface opposite to the upper surface; and an inner electrode layer having a first inner electrode layer and a second inner electrode layer respectively covering the upper surface and the lower surface of the ceramic body, wherein: The first inner electrode layer and the second inner electrode layer are separated by a gap; the first inner electrode layer and the second inner electrode layer have a first surface area and a second surface area respectively in top view and bottom view; and the ratio obtained by dividing the gap by the first surface area or the second surface area is less than 3; an interconnect structure having a first interconnect structure and a second interconnect structure respectively connecting the first inner electrode layer and the second inner electrode layer, and extending below the second inner electrode layer; and an encapsulation layer covering the ceramic body, the inner electrode layer and the interconnect structure, such that a portion of the first interconnect structure and a portion of the second interconnect structure are located below the second inner electrode layer in the encapsulation layer.

2. The ceramic thermistor according to claim 1, wherein the spacing is between 0.15 mm and 0.19 mm, and the first surface area or the second surface area is between 0.08 mm2 and 0.13 mm2.

3. The ceramic thermistor of claim 1 further includes a lead electrode having a first lead electrode and a second lead electrode respectively connected to the first interconnect structure and the second interconnect structure, and extending downward in a direction away from the interconnect structure.

4. The ceramic thermistor of claim 3, wherein the encapsulation layer covers the lead electrode, thereby exposing only a portion of the first lead electrode and a portion of the second lead electrode on the same side.

5. The ceramic thermistor of claim 4 further includes an external electrode layer having a first external electrode layer and a second external electrode layer respectively covering the exposed first lead electrode and the exposed second lead electrode.

6. The ceramic thermistor element according to claim 1, wherein the ceramic body comprises a first component and a second component, wherein: The first component comprises barium, strontium, calcium and a first trace element; the second component comprises titanium, manganese and a second trace element; the first trace element and the second trace element are selected from the group consisting of ytterbium, lanthanum, cerium, antimony, tungsten, neodymium, samarium, europium, thorium, tantalum, erbium, thionium and combinations thereof; and the volume resistivity of the ceramic body is less than 15 Ω·cm.

7. The ceramic thermistor of claim 6, wherein the total mole count of barium, strontium, calcium and the first trace element is 100%, and: strontium accounts for 20% to 25%; calcium accounts for 4.5% to 5%; and the first trace element accounts for 0.13% to 0.17%, thereby the Curie temperature of the ceramic body is 80°C to 130°C.

8. The ceramic thermistor of claim 6, wherein the total moles of titanium, manganese and the second trace element are 100%, and: manganese accounts for 0.01% to 0.03%; and the second trace element accounts for 0.02% to 0.04%.

9. The ceramic thermistor according to claim 8, wherein: The ceramic body has a first resistance value at 25°C; the ceramic body has a second resistance value at 125°C; And the ratio of the second resistance value to the first resistance value is 10 or more.

10. A ceramic thermistor, comprising: a ceramic body assembly having a first ceramic body and a second ceramic body stacked below the first ceramic body; an inner electrode layer having a first inner electrode layer, a second inner electrode layer, a third inner electrode layer and a fourth inner electrode layer, wherein the first inner electrode layer and the second inner electrode layer respectively cover an opposite upper surface and a lower surface of the first ceramic body, and the third inner electrode layer and the fourth inner electrode layer respectively cover an opposite upper surface and a lower surface of the second ceramic body, such that the second inner electrode layer faces the third inner electrode layer; An interconnect structure having a first interconnect structure, a second interconnect structure, and a third interconnect structure, wherein the first interconnect structure is connected between the second inner electrode layer and the third inner electrode layer, the second interconnect structure is connected to the fourth inner electrode layer, and the third interconnect structure is connected to the first inner electrode layer, and the first, second, and third interconnect structures further extend below the fourth inner electrode layer; and an encapsulation layer covering the ceramic body assembly, the inner electrode layer, and the interconnect structure, such that a portion of the first interconnect structure, a portion of the second interconnect structure, and a portion of the third interconnect structure are located below the fourth inner electrode layer within the encapsulation layer.

11. The ceramic thermistor according to claim 10, wherein: The first inner electrode layer and the second inner electrode layer are separated by a distance; the first inner electrode layer and the second inner electrode layer have a first surface area and a second surface area respectively when viewed from above and from below; and the ratio obtained by dividing the distance by the first surface area or the second surface area is less than 3.

12. The ceramic thermistor of claim 10 further includes a lead electrode having a first lead electrode and a second lead electrode, wherein the first lead electrode is connected to the first interconnect structure, and the second lead electrode is connected to the second interconnect structure and the third interconnect structure and extends downward in a direction away from the interconnect structure.

13. The ceramic thermistor of claim 12, wherein the encapsulation layer covers the lead electrode, thereby exposing only a portion of the first lead electrode and a portion of the second lead electrode on the same side.

14. The ceramic thermistor of claim 13 further includes an external electrode layer having a first external electrode layer and a second external electrode layer respectively covering the exposed first lead electrode and the exposed second lead electrode.

15. A ceramic thermistor, comprising: a ceramic body assembly having a first ceramic body and a second ceramic body stacked below the first ceramic body; an inner electrode layer having a first inner electrode layer, a second inner electrode layer, a third inner electrode layer and a fourth inner electrode layer, wherein the first inner electrode layer and the second inner electrode layer respectively cover an opposite upper surface and a lower surface of the first ceramic body, and the third inner electrode layer and the fourth inner electrode layer respectively cover an opposite upper surface and a lower surface of the second ceramic body, and the second inner electrode layer directly contacts the third inner electrode layer; an interconnection structure having a first interconnection structure and a second interconnection structure respectively connecting the first inner electrode layer and the fourth inner electrode layer, and extending below the fourth inner electrode layer; and an encapsulation layer covering the ceramic body assembly, the inner electrode layer and the interconnection structure, such that a portion of the first interconnection structure and a portion of the second interconnection structure are located below the fourth inner electrode layer within the encapsulation layer.

16. The ceramic thermistor according to claim 15, wherein: The first inner electrode layer and the second inner electrode layer are separated by a distance; the first inner electrode layer and the second inner electrode layer have a first surface area and a second surface area respectively when viewed from above and from below; and the ratio obtained by dividing the distance by the first surface area or the second surface area is less than 3.

17. The ceramic thermistor of claim 16 further includes a lead electrode having a first lead electrode and a second lead electrode respectively connected to the first interconnect structure and the second interconnect structure, and extending downward in a direction away from the interconnect structure.

18. The ceramic thermistor of claim 17, wherein the encapsulation layer covers the lead electrode, thereby exposing only a portion of the first lead electrode and a portion of the second lead electrode on the same side.

19. The ceramic thermistor of claim 18 further includes an external electrode layer having a first external electrode layer and a second external electrode layer respectively covering the exposed first lead electrode and the exposed second lead electrode.

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