Surface electrode type NTC (Negative Temperature Coefficient) thermistor

Abstract

The utility model relates to the technical field of resistor manufacturing, in particular to a surface electrode type NTC (Negative Temperature Coefficient) thermistor. The surface electrode type NTC thermistor comprises an NTC ceramic substrate, an electrode layer and a protective layer, the electrode layer comprises a surface electrode and two outer electrodes, the electrode layer is located on the NTC ceramic substrate, and the protective layer is located above the electrode layer. The device has the advantages of high manufacturing precision, simplicity in manufacturing and low cost.

Description

Technical Field

[0001] The utility model relates to the technical field of resistor manufacturing, in particular to a surface electrode type NTC thermistor. Background Art

[0002] In the future, with the continuous development of science and technology, chip NTC thermistors will gradually realize the development trend of intelligence, miniaturization and high efficiency, bringing more convenience and innovation to mankind. Negative temperature coefficient thermistors (NTC thermistors) are widely used in electronics, automobiles, medical care, energy and other fields. Their structural structures and types are also very rich, which can meet the needs of different fields. At present, there are two main structures of existing NTC thermistor products. The first structure is without internal electrodes, that is, block ceramic NTC thermistors, which are composed of five parts, inner core material, silver plating, electroplated nickel layer, electroplated tin layer and glass packaging layer. This structure is thicker as a whole, and the temperature response time is relatively long. In addition, the thermal shock of welding has a greater impact on its resistance and B value, which will cause resistance drift, thereby affecting the temperature measurement accuracy. In addition, the resistance provided by this structure is not flexible enough. The second structure has an internal electrode, that is, a multilayer ceramic laminated NTC thermistor. This product has a multilayer ceramic structure with an internal electrode, similar to the structure of MLCC. The resistance and accuracy are usually adjusted by adjusting the internal electrode. It is affected by the thermal shock of welding, mechanical stress difference, thermal shock and circuit board bending, which are likely to cause the product to crack and fail.

[0003] Therefore, there is a need for a surface electrode NTC thermistor with high precision, simple manufacturing and low cost. Utility Model Content

[0004] In order to solve the above problems, a surface electrode type NTC thermistor with high precision, simple manufacturing and low cost is provided. The utility model adopts the following technical solutions.

[0005] A surface electrode type NTC thermistor comprises an NTC ceramic substrate, an electrode layer and a protective layer, wherein the electrode layer comprises a surface electrode and two outer electrodes, the electrode layer is located on the NTC ceramic substrate, and the protective layer is located above the electrode layer.

[0006] The utility model adjusts the resistance value and precision through the surface electrode and ensures the stability of the whole resistor through the protective layer, and has the advantages of simple manufacturing and low cost.

[0007] Preferably, the NTC ceramic substrate is made of two or more metal oxides of manganese, copper, silicon, cobalt, iron, nickel, and zinc, or one of silicon carbide, tin selenide, and tantalum nitride.

[0008] The resistivity and material constants of these materials will vary with the material composition ratio, sintering atmosphere, sintering temperature and structural state. According to the resistance law, the resistance R of a conductor is proportional to its length L and resistivity ρ, and inversely proportional to its cross-sectional area S. The ceramic substrate prepared by the above materials has good temperature sensitivity.

[0009] Preferably, the surface electrode comprises a left electrode and a right electrode, each of the left electrode and the right electrode comprises a plurality of electrode sheets, the electrode sheets of the left electrode and the electrode sheets of the right electrode are alternately arranged, the external electrode comprises a left external electrode and a right external electrode, the left external electrode is connected to the left side of the left electrode, and the right external electrode is connected to the right side of the right electrode.

[0010] The surface electrodes of the utility model adopt a finger-insertion design, and there is a directly facing area between the surface electrodes. This structure enables the utility model to adjust the resistance between the two electrodes with higher precision and ensures the yield rate of the product.

[0011] Preferably, the outer electrode comprises a base layer, a barrier layer and a welding layer from the inside to the outside.

[0012] The utility model adopts an external electrode structure, which is connected through a base layer and a surface electrode. The barrier layer can prevent the electrode from being affected during welding, and the welding layer is connected to the welding pad.

[0013] Preferably, a welding pad is provided outside the welding layer, and the welding pad includes a top fixing plate, a bottom fixing plate and a side fixing plate. The NTC ceramic substrate, the electrode layer and the protective layer are all located between the top fixing plate and the bottom fixing plate, and the NTC ceramic substrate, the electrode layer and the protective layer are all located on the inner side of the side fixing plate.

[0014] The utility model adopts the structure, and welding is performed when the utility model is installed, which can play a role in protecting the resistor.

[0015] Preferably, the protective layer is made of glass material.

[0016] Preferably, the surface electrode and the external electrode are covered on the NTC ceramic substrate by screen printing.

[0017] The utility model adopts the screen printing method for processing, which not only improves the production efficiency and can process a large number of components in a short time, but also helps to reduce the processing cost.

[0018] Preferably, the surface electrode further comprises a middle electrode, and the middle electrode and the left electrode and the right electrode are parallel to each other.

[0019] In the processing of the utility model, firstly, an integral electrode is printed on the NTC ceramic substrate by screen printing, and then a left electrode, a right electrode and a middle electrode are cut by laser, and the facing area between the electrodes is adjusted by laser.

[0020] Preferably, the surface electrode is cut by laser light spots to change the facing area of ​​the electrode, thereby adjusting the resistance value of the thermistor.

[0021] In the production process of the utility model, the NTC ceramic substrate is first prepared, and then the electrode is printed on the ceramic substrate by screen printing, sintered after drying, and then precisely cut by laser to control the resistance, and then coated with a protective layer, the protective layer uses silicon dioxide particles, and the protective layer is sintered after drying to form a protective layer after sintering, and finally the sintered substrate is folded, silver dipped or sputtered, silver burned and electroplated in sequence. The utility model adopts the folding method for processing, which has the advantages of fast processing speed and high processing precision.

[0022] Preferably, the NTC thermistor has a length of 0.4-2.0 mm, a width of 0.2-1.25 mm, and a height of 0.2-0.85 mm.

[0023] The resistor size of the utility model is very small, and it is difficult to process small-sized components. The utility model adopts a surface printing method to process a large number of components in a short time, and then adopts a folding strip method to enhance the processing accuracy of the utility model.

[0024] The beneficial effects of the utility model are: 1. The utility model has the advantage of high processing precision; 2. The utility model has the advantage of low cost; 3. The utility model has the advantages of high production efficiency and high yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the utility model;

[0026] Figure 2 It is a structural schematic diagram of Example 1;

[0027] Figure 3 It is a structural schematic diagram of Example 2;

[0028] Figure 4 It is a structural schematic diagram of Example 3;

[0029] Figure 5 is a schematic diagram of the structure of the left outer electrode;

[0030] Figure 6 It is the production flow chart of the utility model. DETAILED DESCRIPTION

[0031] The utility model is further explained below in conjunction with specific implementation cases.

[0032] Example 1

[0033] A surface electrode 4 type NTC thermistor includes an NTC ceramic substrate 1, an electrode layer 2 and a protective layer 3, wherein the electrode layer 2 includes a surface electrode 4 and two external electrodes 5, the electrode layer 2 is located on the NTC ceramic substrate 1, and the protective layer 3 is located above the electrode layer 2. The NTC ceramic substrate 1 is made of two or more metal oxides selected from manganese, copper, silicon, cobalt, iron, nickel, and zinc, or one of silicon carbide, tin selenide, and tantalum nitride. The surface electrode 4 includes a left electrode 6 and a right electrode 7, and the external electrode 5 includes a left external electrode 8 and a right external electrode 9, wherein the left external electrode 8 is connected to the left side of the left electrode 6, and the right external electrode 9 is connected to the right side of the right electrode 7. The external electrode 5 includes a base layer 10, a barrier layer 11, and a welding layer 12 from the inside to the outside. The welding layer 12 is provided with a welding pad 13 outside, and the welding pad 13 includes a top fixing plate 14, a bottom fixing plate 15 and a side fixing plate 16. The NTC ceramic substrate 1, the electrode layer 2 and the protective layer 3 are all located between the top fixing plate 14 and the bottom fixing plate 15, and the NTC ceramic substrate 1, the electrode layer 2 and the protective layer 3 are all located inside the side fixing plate 16. The protective layer 3 is made of glass material. The surface electrode 4 and the external electrode 5 are covered on the NTC ceramic substrate by screen printing. The surface electrode 4 changes the corresponding area of ​​the electrode by cutting with a laser spot, thereby adjusting the resistance value of the thermistor. The NTC thermistor has a length of 0.4 mm, a width of 0.2 mm and a height of 0.2 mm.

[0034] In the production process of the utility model, the NTC ceramic substrate is first prepared, and then the electrode is printed on the ceramic substrate by screen printing, sintered after drying, and then precisely cut by laser to control the resistance, and then a protective layer is coated, and sintered after the protective layer is dried, and finally the sintered substrate is folded, silver dipped or sputtered, silver burned and electroplated in sequence. The utility model adopts the folding method for processing, which has the advantages of fast processing speed and high processing precision.

[0035] Example 2

[0036] A surface electrode 4 type NTC thermistor comprises an NTC ceramic substrate 1, an electrode layer 2 and a protective layer 3, wherein the electrode layer 2 comprises a surface electrode 4 and two external electrodes 5, wherein the electrode layer 2 is located on the NTC ceramic substrate 1, and the protective layer 3 is located above the electrode layer 2. The NTC ceramic substrate 1 is made of two or more metal oxides selected from manganese, copper, silicon, cobalt, iron, nickel and zinc, or is made of one of silicon carbide, tin selenide and tantalum nitride. The surface electrode 4 comprises a left electrode 6 and a right electrode 7, wherein the left electrode 6 and the right electrode 7 each comprise a plurality of electrode sheets 17, wherein the electrode sheets 17 of the left electrode 6 and the electrode sheets 17 of the right electrode 7 are arranged alternately, wherein the external electrode 5 comprises a left external electrode 8 and a right external electrode 9, wherein the left external electrode 8 is connected to the left side of the left electrode 6, and the right external electrode 9 is connected to the right side of the right electrode 7. The external electrode 5 comprises a base layer 10, a barrier layer 11 and a welding layer 12 from the inside to the outside. The welding layer 12 is provided with a welding pad 13 outside, and the welding pad 13 includes a top fixing plate 14, a bottom fixing plate 15 and a side fixing plate 16. The NTC ceramic substrate 1, the electrode layer 2 and the protective layer 3 are all located between the top fixing plate 14 and the bottom fixing plate 15, and the NTC ceramic substrate 1, the electrode layer 2 and the protective layer 3 are all located inside the side fixing plate 16. The protective layer 3 is made of glass material. The surface electrode 4 and the external electrode 5 are covered on the NTC ceramic substrate by screen printing. The surface electrode 4 changes the corresponding area of ​​the electrode by cutting with a laser spot, thereby adjusting the resistance value of the thermistor. The NTC thermistor has a length of 0.4 mm, a width of 0.2 mm and a height of 0.2 mm.

[0037] Example 3

[0038] A surface electrode 4 type NTC thermistor comprises an NTC ceramic substrate 1, an electrode layer 2 and a protective layer 3, wherein the electrode layer 2 comprises a surface electrode 4 and two external electrodes 5, wherein the electrode layer 2 is located on the NTC ceramic substrate 1, and the protective layer 3 is located above the electrode layer 2. The NTC ceramic substrate 1 is made of two or more metal oxides selected from manganese, copper, silicon, cobalt, iron, nickel and zinc, or is made of one of silicon carbide, tin selenide and tantalum nitride. The surface electrode 4 comprises a left electrode 6 and a right electrode 7, wherein the left electrode 6 and the right electrode 7 each comprise a plurality of electrode sheets 17, wherein the electrode sheets 17 of the left electrode 6 and the electrode sheets 17 of the right electrode 7 are arranged alternately, and the surface electrode 4 further comprises an intermediate electrode 18, wherein the intermediate electrode and the left electrode 6 and the right electrode 7 are parallel to each other. The external electrode 5 comprises a left external electrode 8 and a right external electrode 9, wherein the left external electrode 8 is connected to the left side of the left electrode 6, and the right external electrode 9 is connected to the right side of the right electrode 7. The external electrode 5 includes a base layer 10, a barrier layer 11 and a welding layer 12 from the inside to the outside. The welding layer 12 is provided with a pad 13 outside, and the pad 13 includes a top fixing plate 14, a bottom fixing plate 15 and a side fixing plate 16. The NTC ceramic substrate 1, the electrode layer 2 and the protective layer 3 are all located between the top fixing plate 14 and the bottom fixing plate 15, and the NTC ceramic substrate 1, the electrode layer 2 and the protective layer 3 are all located inside the side fixing plate 16. The protective layer 3 is made of glass material. The surface electrode 4 and the external electrode 5 are covered on the NTC ceramic substrate by screen printing. The surface electrode 4 changes the corresponding area of ​​the electrode by cutting with a laser spot, thereby adjusting the resistance value of the thermistor. The NTC thermistor has a length of 0.4 mm, a width of 0.2 mm and a height of 0.2 mm.

[0039] In the production process of the utility model, the NTC ceramic substrate is first prepared, and then the electrode is printed on the ceramic substrate by screen printing, sintered after drying, and then precisely cut by laser to control the resistance, and then a protective layer is coated, and sintered after the protective layer is dried, and finally the sintered substrate is folded, silver dipped or sputtered, silver burned and electroplated in sequence. The utility model adopts the folding method for processing, which has the advantages of fast processing speed and high processing precision.

[0040] In addition, when the product of the utility model is used, the outer electrode and the welding pad are welded and installed.

[0041] The detection structure of the utility model is as follows:

[0042]

Claims

1. A surface electrode type NTC thermistor, characterized in that: It comprises an NTC ceramic substrate, an electrode layer and a protective layer, wherein the electrode layer comprises a surface electrode and two external electrodes, the electrode layer is located on the NTC ceramic substrate, and the protective layer is located above the electrode layer.

2. A surface electrode type NTC thermistor according to claim 1, characterized in that: The surface electrode includes a left electrode and a right electrode, each of which includes a plurality of electrode sheets, the electrode sheets of the left electrode and the electrode sheets of the right electrode are arranged alternately, and the external electrode includes a left external electrode and a right external electrode, the left external electrode is connected to the left side of the left electrode, and the right external electrode is connected to the right side of the right electrode.

3. A surface electrode type NTC thermistor according to claim 2, characterized in that: The outer electrode comprises a base layer, a barrier layer and a welding layer from the inside to the outside.

4. A surface electrode type NTC thermistor according to claim 3, characterized in that: The welding layer is provided with a welding pad outside, and the welding pad includes a top fixing plate, a bottom fixing plate and a side fixing plate. The NTC ceramic substrate, the electrode layer and the protective layer are all located between the top fixing plate and the bottom fixing plate, and the NTC ceramic substrate, the electrode layer and the protective layer are all located on the inner side of the side fixing plate.

5. A surface electrode type NTC thermistor according to claim 4, characterized in that: The protective layer is made of glass material.

6. A surface electrode type NTC thermistor according to claim 5, characterized in that: The surface electrode and the outer electrode are covered on the NTC ceramic substrate by screen printing.

7. A surface electrode type NTC thermistor according to claim 6, characterized in that: The surface electrode also includes a middle electrode, and the middle electrode and the left electrode and the right electrode are parallel to each other.

8. A surface electrode type NTC thermistor according to claim 7, characterized in that: The surface electrode is cut by laser light spots to change the length and width of the electrode, thereby adjusting the resistance value of the thermistor.

9. A surface electrode type NTC thermistor according to claim 8, characterized in that: The NTC thermistor has a length of 0.4-2.0 mm, a width of 0.2-1.25 mm, and a height of 0.2-0.85 mm.

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