CN-121983401-A - Ceramic thermosensitive element

Abstract

A ceramic thermal element includes a ceramic body, an inner electrode layer, an interconnect structure, and a package layer. The inner electrode layer is provided with a first inner electrode layer and a second inner electrode layer which are respectively covered on the upper surface and the lower surface of the ceramic body. The interconnection structure is provided with a first interconnection structure and a second interconnection structure which are respectively connected with the first inner electrode layer and the second inner electrode layer and extend to the lower part of the second inner electrode layer. The encapsulation layer encapsulates 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 on the underside of the encapsulation layer.

Inventors

• LI PINXUAN
• Shen Baizhi
• CAI DONGCHENG
• SHA YIAN

Assignees

• 聚鼎科技股份有限公司

Dates

Publication Date

20260505

Application Date

20250725

Priority Date

20250711

Claims (20)

1. 1. A ceramic thermal element comprising: a ceramic body having an upper surface and a lower surface opposite the upper surface; 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; An interconnection structure having a first interconnection structure and a second interconnection structure connected to the first and second internal electrode layers respectively and extending below the second internal electrode layer, and And the packaging layer is used for coating the ceramic body, the inner electrode layer and the interconnection structure, so that part of the first interconnection structure and part of the second interconnection structure are positioned below the second inner electrode layer in the packaging layer.
2. 2. The ceramic thermal element of claim 1, wherein: the first inner electrode layer is separated from the second inner electrode layer by a distance; the first and second internal electrode layers have a first and second surface area in top and bottom views, respectively, and The ratio of the spacing divided by the first surface area or the second surface area is less than 3.
3. 3. A ceramic thermal element according to claim 2, wherein the spacing is between 0.15mm and 0.19mm and the first surface area or the second surface area is between 0.08mm 2 and 0.13mm 2 .
4. 4. The ceramic thermal element according to claim 1, further comprising an extraction electrode having a first extraction electrode and a second extraction electrode respectively connected to the first interconnect structure and the second interconnect structure and extending downward in a direction away from the interconnect structure.
5. 5. The ceramic thermal element according to claim 4, wherein the encapsulation layer encapsulates the extraction electrodes, whereby only a portion of the first extraction electrodes and a portion of the second extraction electrodes are exposed on the same side.
6. 6. The ceramic heat sensitive element of claim 5 further comprising an outer electrode layer having a first outer electrode layer and a second outer electrode layer covering the exposed first lead electrode and the exposed second lead electrode, respectively.
7. 7. The ceramic thermal element of claim 1, wherein the ceramic body comprises a first set of components and a second set of components, wherein: The first group of components comprises barium, strontium, calcium and a first trace element; The second group of components 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, praseodymium, neodymium, samarium, europium, gadolinium, tantalum, erbium, thulium, and combinations thereof, and The volume resistivity of the ceramic body is less than 15 Ω·cm.
8. 8. The ceramic thermal element according to claim 7, wherein the total mole number of barium, strontium, calcium and the first trace element is 100%, and: strontium accounting for 20 to 25 percent; Calcium content of 4.5-5%, and The first trace element comprises 0.13% to 0.17%, whereby the ceramic body has a curie point of 80 ℃ to 130 ℃.
9. 9. The ceramic thermal element according to claim 7, wherein the total mole number of titanium, manganese and the second trace element is 100%, and: Manganese content of 0.01 to 0.03%, and The second trace element accounts for 0.02 to 0.04 percent.
10. 10. The ceramic thermal element of claim 9, wherein: the ceramic body has a first resistance value at 25 ℃; the ceramic body has a second resistance value at 125℃, and The ratio of the second resistance divided by the first resistance is 10 or more.
11. 11. A ceramic thermal element comprising: a ceramic body group, which is provided with 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 upper surface and a lower surface of the first ceramic body opposite to each other, and the third inner electrode layer and the fourth inner electrode layer respectively cover an upper surface and a lower surface of the second ceramic body opposite to each other, 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 and third internal electrode layers, the second interconnect structure is connected to the fourth internal electrode layer, and the third interconnect structure is connected to the first internal electrode layer, and the first, second and third interconnect structures further extend below the fourth internal electrode layer, and And the packaging layer is used for coating the ceramic body group, the inner electrode layer and the interconnection structure, so that part of the first interconnection structure, part of the second interconnection structure and part of the third interconnection structure are positioned below the fourth inner electrode layer in the packaging layer.
12. 12. The ceramic thermal element of claim 11, wherein: the first inner electrode layer is separated from the second inner electrode layer by a distance; the first and second internal electrode layers have a first and second surface area in top and bottom views, respectively, and The ratio of the spacing divided by the first surface area or the second surface area is less than 3.
13. 13. The ceramic thermal element according to claim 11, further comprising an extraction electrode having a first extraction electrode and a second extraction electrode, wherein the first extraction electrode is connected to the first interconnect structure and the second extraction electrode is connected to the second interconnect structure and the third interconnect structure and extends downward in a direction away from the interconnect structure.
14. 14. A ceramic thermal element according to claim 13, wherein the encapsulation layer encapsulates the extraction electrodes, whereby only a portion of the first extraction electrode and a portion of the second extraction electrode are exposed on the same side.
15. 15. The ceramic heat sensitive element of claim 14 further comprising an outer electrode layer having a first outer electrode layer and a second outer electrode layer covering the exposed first lead electrode and the exposed second lead electrode, respectively.
16. 16. A ceramic thermal element comprising: a ceramic body group, which is provided with 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 upper surface and a lower surface of the first ceramic body opposite to each other, the third inner electrode layer and the fourth inner electrode layer respectively cover an upper surface and a lower surface of the second ceramic body opposite to each other, 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 connected to the first and fourth internal electrode layers respectively and extending below the fourth internal electrode layer, and And the packaging layer is used for coating the ceramic body group, the inner electrode layer and the interconnection structure, so that part of the first interconnection structure and part of the second interconnection structure are positioned below the fourth inner electrode layer in the packaging layer.
17. 17. The ceramic thermal element of claim 16, wherein: the first inner electrode layer is separated from the second inner electrode layer by a distance; the first and second internal electrode layers have a first and second surface area in top and bottom views, respectively, and The ratio of the spacing divided by the first surface area or the second surface area is less than 3.
18. 18. The ceramic thermal element according to claim 17, further comprising an extraction electrode having a first extraction electrode and a second extraction electrode connected to the first interconnect structure and the second interconnect structure, respectively, and extending downward in a direction away from the interconnect structure.
19. 19. A ceramic thermal element according to claim 18, wherein the encapsulation layer encapsulates the extraction electrodes, whereby only a portion of the first extraction electrode and a portion of the second extraction electrode are exposed on the same side.
20. 20. The ceramic heat sensitive element of claim 19 further comprising an outer electrode layer having a first outer electrode layer and a second outer electrode layer covering the exposed first lead electrode and the exposed second lead electrode, respectively.

Description

Ceramic thermosensitive element Technical Field The present invention relates to a ceramic thermal element, and more particularly, to a low-resistance and packaged ceramic thermal element. Background The resistance of conventional positive temperature coefficient (Positive Temperature Coefficient, PTC) devices responds very sharply to temperature changes. When the PTC element is in normal use, the resistance can maintain extremely low value, so that the circuit can operate normally. However, when the temperature rises to a critical temperature or Curie point due to the occurrence of an overcurrent or an overtemperature, the resistance value thereof will bounce to a high resistance state (for example, 10 4 Ω or more), so-called trigger (trip), and the excessive current will be cut off, so as to achieve the purpose of protecting the battery or the circuit element. Therefore, PTC elements have been found to be integrated in various circuit elements to prevent damage by overcurrent. Positive temperature coefficient devices can be broadly divided into two general categories, polymeric positive temperature coefficient (Polymer Positive Temperature Coefficient, PPTC) devices and ceramic positive temperature coefficient (Ceramic Positive Temperature Coefficient, CPTC) devices. The conventional PPTC device has a resistance after triggering (trip) that is not easily restored to its original value, i.e., has poor resistance decay (RESISTANCE HYSTERESIS) characteristics and is not resistant to high voltages. Although CPTC devices generally have high voltage resistance and their resistances can be restored to be closer to the original values, the CPTC devices themselves have poor conductivity due to their high normal resistances, thus limiting their application range. With respect to the aforementioned CPTC element, reference is made to FIGS. 1a and 1b, which are a perspective view and a sectional view along line AA of a conventional ceramic thermal element 100. The core component of the ceramic thermal element 100 is a ceramic body 1 having positive temperature coefficient characteristics. In order to make the ceramic body 1 electrically connected to an external power source well, ohmic contact electrodes having low resistance must be printed on both ends thereof, as shown in fig. 1a and 1b, for the first and second internal electrode layers 2a and 2b. Then, an external electrode layer (not shown) may be formed on the surfaces of the first and second internal electrode layers 2a and 2b by electroplating to form a finished product having a specific length L1, width W1 and thickness T1. However, the first and second inner electrode layers 2a and 2b of the conventional ceramic thermosensitive element 100 are located on both end faces, which may cause the gap G1 between the two electrodes to be pulled too far, resulting in excessively high resistance when the element is not activated (i.e., when not triggered). If the distance between the two end surfaces of the ceramic body 1 is simply shortened in order to reduce the resistance, other changes in electrical characteristics tend to be more serious due to miniaturization, and the performance is less stable. In view of the foregoing, there is a need to develop a new ceramic thermal element that has low resistance and stable and good performance in other electrical characteristics. Disclosure of Invention According to one aspect of the present invention, a ceramic thermal element includes a ceramic body, an inner electrode layer, an interconnect structure, and a package layer. The ceramic body has an upper surface and a lower surface opposite the upper surface. The inner electrode layer is provided with a first inner electrode layer and a second inner electrode layer which are respectively covered on the upper surface and the lower surface of the ceramic body. The interconnection structure is provided with a first interconnection structure and a second interconnection structure which are respectively connected with the first inner electrode layer and the second inner electrode layer and extend to the lower part of the second inner electrode layer. The encapsulation layer encapsulates the ceramic body, the inner electrode layer and the interconnection structure, so that a part of the first interconnection structure and a part of the second interconnection structure are positioned below the second inner electrode layer in the encapsulation layer. According to some embodiments, the first inner electrode layer is separated from the second inner electrode layer by a distance. The first and second internal electrode layers have first and second surface areas, respectively, in top and bottom views. The ratio of this spacing divided by the first surface area or the second surface area is less than 3. According to some embodiments, this spacing is between 0.15mm and 0.19mm, while the first surface area or the second surface area is between 0.08mm 2 and 0.13mm 2. According to some embo