Resistor and battery assembly

Abstract

The application discloses a resistor and a battery assembly, and relates to the technical field of batteries. The resistor comprises a resistor body, a first electrode, a second electrode and a passivation layer; wherein the resistor body has a first surface and a second surface arranged oppositely, the first surface has a resistor region and two electrode regions, the first electrode is arranged in one electrode region, the second electrode is arranged in the other electrode region, and the passivation layer covers the resistor region and the second surface. The resistor provided by the application covers the resistor region and the second surface with the passivation layer, reduces the surface leakage or short circuit of the resistor body by using the high resistivity of the passivation layer, makes the resistance value of the resistor meet the design expectation, and thus the resistor can be free of an insulating substrate and adhesive, the overall thickness of the resistor is reduced, and the resistor is miniaturized.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a resistor and a battery assembly. Background Technology

[0002] In the design of battery modules, precision resistors are usually placed in the battery head area. Due to the high thickness of precision resistors, the thickness of the entire PCM (Protection Circuit Module) also increases, which directly affects the overall thickness of the battery head and limits the improvement of the energy density of the battery module. Utility Model Content

[0003] In view of this, this application provides a resistor and a battery assembly, which aims to solve one of the technical problems in the prior art.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, this application provides a resistor, including a resistive body, a first electrode, a second electrode, and a passivation layer; wherein the resistive body has a first surface and a second surface disposed opposite to each other, the first surface has a resistive region and two electrode regions, the first electrode is disposed in one of the electrode regions, the second electrode is disposed in the other electrode region, and the passivation layer covers the resistive region and the second surface.

[0005] In an optional embodiment, the first electrode includes a base layer, an isolation layer, and a solder layer. The base layer is connected to the resistor and is used to prevent copper ions in the resistor layer from diffusing towards the solder layer. The isolation layer is disposed on the side of the base layer away from the resistor and is used to prevent the base layer from reacting with the solder layer. The solder layer is disposed on the side of the isolation layer away from the resistor.

[0006] In an optional embodiment, the base layer is made of nickel; the insulating layer is made of palladium; and the solder layer is made of gold.

[0007] In an optional embodiment, the thickness of the base layer is D1, satisfying: 3μm≤D1≤6μm; the thickness of the isolation layer is D2, satisfying: 0.05≤D2≤0.15μm; and the thickness of the welding layer is D3, satisfying: 0.03≤D3≤0.1μm.

[0008] In an optional embodiment, the first electrode includes a base layer and a solder layer. The base layer is connected to the resistor, and the solder layer is disposed on the side of the base layer away from the resistor. The base layer is connected to the resistor and is used to prevent copper ions in the resistor layer from diffusing towards the solder layer.

[0009] In an optional embodiment, the base layer is made of nickel; the solder layer is made of gold.

[0010] In an optional embodiment, the thickness of the base layer is D4, satisfying: 3μm≤D4≤6μm; the thickness of the welding layer is D5, satisfying: 0.03≤D5≤0.1μm.

[0011] In an optional embodiment, the first electrode and the second electrode are made of copper.

[0012] In an optional embodiment, the first electrode and the second electrode are made of nickel.

[0013] In an optional embodiment, the first electrode and the second electrode have the same structure. The first electrode includes a copper layer and a nickel layer. The copper layer is disposed on the first surface of the resistive body, and the nickel layer is disposed on the surface of the copper layer away from the resistive body.

[0014] In an optional embodiment, the first electrode layer and the second electrode layer have the same thickness, and the thickness of the first electrode layer is D, satisfying: 3 ≤ D ≤ 20 μm; and / or The passivation layer is an oxide layer, a polymer layer, or an insulating coating.

[0015] Secondly, this application provides a battery assembly, including a resistor, a protection board, and a battery cell as described in any of the above embodiments, wherein the resistor is electrically connected to the protection board, and the protection board is electrically connected to the battery cell.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: This application proposes a resistor, including a resistive body, a first electrode, a second electrode, and a passivation layer; wherein, the resistive body has a first surface and a second surface disposed opposite to each other, the first electrode is disposed in one electrode region, the second electrode is disposed in another electrode region, the first surface has a resistive region and two electrode regions, the passivation layer covers the resistive region and the second surface, and on the resistive region, the edge of the passivation layer coincides with the edge of the resistive region, so that the surfaces of the first electrode and the second electrode are exposed, increasing the welding area and reducing the occurrence of cold solder joints; Furthermore, by covering the resistive region and the second surface with a passivation layer, the high resistivity of the passivation layer reduces leakage current or short circuits on the resistor surface, ensuring the resistor value meets design expectations. This eliminates the need for an insulating substrate and adhesive, reducing the overall thickness of the resistor (to approximately 0.11 mm) and promoting miniaturization. When the resistor is assembled on the PCM, the thickness of the PCM is also reduced, decreasing the overall thickness of the battery header and increasing the energy density of the battery module. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This paper shows a schematic diagram of the structure of a resistor in some embodiments of this application; Figure 2 This is shown as a second schematic diagram of the resistor structure in some embodiments of this application; Figure 3 This is shown as a third schematic diagram of the resistor structure in some embodiments of this application; Figure 4 The fourth schematic diagram of the resistor structure in some embodiments of this application is shown; Figure 5 This illustration shows one of the structural schematic diagrams of the resistor in the resistor fabrication process of some embodiments of this application; Figure 6 This is shown as a second schematic diagram of the resistor structure in the resistor fabrication process of some embodiments of this application; Figure 7 The third schematic diagram of the resistor structure in the resistor fabrication process of some embodiments of this application is shown.

[0019] Explanation of key component symbols: 100-Resistor; 110-Resistor element; 120-First electrode; 130-Second electrode; 140-Passivation layer; 111-First surface; 112-Second surface; 1111-Resistor region; 1112-Electrode region; 121-Base layer; 122-Solder layer; 123-Isolation layer; 200-Photosensitive adhesive. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] In related technologies, a resistor includes an insulating substrate, a resistive element, and electrodes. The electrodes are connected to the upper surface of the resistive element, and the insulating substrate is attached to the lower surface of the resistive element. The resistive element and the insulating substrate are bonded together using adhesive, thus obtaining a composite plate formed by the bonding of the resistive element and the insulating substrate. By using an insulating substrate (such as ceramic, epoxy resin, etc.) as a non-conductive base, electrical contact is prevented between the resistive element and external conductors (such as circuit boards or metal casings), avoiding current leakage or short circuits, and ensuring that the resistor value meets design expectations. However, the insulating substrate and adhesive increase the overall thickness of the resistor (typically, the thickness of a resistor with an insulating substrate is 0.25~0.4mm).

[0026] In particular, when resistors are assembled on the battery's PCM (Protection Circuit Module), the thickness of the PCM increases, affecting the overall thickness of the battery head and limiting the improvement of the battery module's energy density.

[0027] In response to the above problems, such as Figure 1 As shown, an embodiment of this application provides a resistor 100, which includes a resistive body 110, a first electrode 120, a second electrode 130, and a passivation layer 140.

[0028] The resistor element 110 is plate-shaped and made of copper alloy. Copper alloys include manganese-copper alloys, nickel-copper alloys, manganese-copper-tin alloys, and alloys with similar properties. Copper alloys have low resistivity and the resistor 100 has a good temperature coefficient.

[0029] The resistor 110 has a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 and the second surface 112 are spaced apart along the thickness direction of the resistor 110. Figure 1 In the diagram, the first surface 111 is the upper surface of the resistor 110, and the second surface 112 is the lower surface.

[0030] like Figure 1 As shown, the first surface 111 has a resistive region 1111 and two electrode regions 1112. A first electrode 120 is disposed in one electrode region 1112, and a second electrode 130 is disposed in the other electrode region 1112. The two electrode regions are spaced apart, such that the first electrode 120 and the second electrode 130 are spaced apart.

[0031] A passivation layer 140 covers the resistive region 1111 and the second surface 112. The edges of the resistive region 1111 and the electrode region 1112 are joined. On the resistive region 1111, the edge of the passivation layer 140 coincides with the edge of the resistive region 1111, exposing the surfaces of the first electrode 120 and the second electrode 130, increasing the welding area of ​​the first electrode 120 and the second electrode 130, and reducing the occurrence of cold solder joints.

[0032] By using a passivation layer 140 to cover the resistive region 1111 and the second surface 112, and utilizing the high resistivity of the passivation layer 140, leakage current or short circuits on the surface of the resistor 110 are reduced, ensuring that the resistance value of the resistor 100 meets the design expectations. This eliminates the need for an insulating substrate and adhesive for the resistor 100, reducing the overall thickness of the resistor 100 (to approximately 0.11 mm) and promoting miniaturization. When the resistor 100 is assembled on the PCM of the battery, the thickness of the PCM is also reduced, decreasing the overall thickness of the battery head and increasing the energy density of the battery assembly.

[0033] Furthermore, since the second surface 112 of the resistor 110 in this application does not have an insulating substrate and adhesive, it is convenient to repair the resistor and calibrate the resistance value from the back of the resistor 110. At the same time, the high density of the passivation layer 140 can isolate air, moisture or chemicals, and improve the long-term stability of the resistor 100. It needs to be explained, such as Figure 1 As shown, the resistor 110 also includes a side surface connecting the first surface 111 and the second surface 112, and the passivation layer 140 can also cover the side surface to improve the surface insulation of the resistor 110.

[0034] In one embodiment, such as Figure 3 As shown, both the first electrode 120 and the second electrode 130 are made of copper. The first electrode 120 layer and the second electrode 130 layer have the same thickness, with the first electrode 120 layer having a thickness of 0.3-5 μm. Alternatively, gold wire bonding can be used to bond the copper layer, improving the welding reliability and conductivity of the electrodes, reducing the contact resistance 100 between the electrodes and the external circuit, and improving the stability and accuracy of the resistance value of resistor 100.

[0035] In one embodiment, such as Figure 3 As shown, both the first electrode 120 and the second electrode 130 are made of nickel.

[0036] In one embodiment, such as Figure 4 As shown, the first electrode 120 and the second electrode 130 are identical. The first electrode 120 includes a copper layer and a nickel layer. The copper layer is connected to the resistor 110, and the nickel layer is connected to the side of the copper layer away from the resistor 110.

[0037] In practical applications, it has been found that when electrodes are typically made of copper, they are usually soldered to pads on the circuit board using a soldering process. However, the soldering properties of copper and tin are prone to forming unstable intermetallic compounds at the solder interface. This poor solder interface leads to increased contact resistance, which in turn affects the overall resistance accuracy and stability of the resistor.

[0038] It was also found that when the electrodes are made of tin, or when tin is used as the solder layer for the electrodes, the tin is easily oxidized, which affects the contact resistance between the electrodes and the external solder pads, reducing the overall resistance accuracy and stability of the resistor.

[0039] To eliminate the above-mentioned adverse effects, such as Figure 1 and Figure 2 The first electrode 120 layer includes a base layer 121 and a solder layer 122, or the first electrode 120 includes a base layer 121, an isolation layer 123 and a solder layer 122.

[0040] It should be noted that in this embodiment, the first electrode layer 120 and the second electrode layer 130 have the same structure.

[0041] like Figure 2 As shown, when the first electrode 120 layer includes a base layer 121 and a solder layer 122.

[0042] The base layer 121 is connected to the resistor 110, and the solder layer 122 is located on the side of the base layer 121 away from the resistor 110. The base layer 121 acts as a buffer zone between the resistor 110 and the solder layer 122, preventing copper ions in the resistor 110 from diffusing into the solder layer 122 and improving the stability of the soldering.

[0043] In one embodiment, the substrate 121 is made of nickel.

[0044] In some embodiments, the thickness of the substrate layer 121 is D4, satisfying: 3μm ≤ D4 ≤ 6μm. Specifically, D4 can be 3μm, 3.2μm, 3.4μm, 3.6μm, 3.8μm, 4μm, 4.2μm, 4.4μm, 4.6μm, 4.8μm, 5μm, 5.2μm, 5.4μm, 5.6μm, 5.8μm, 6μm, etc., and is not limited to the values ​​in the examples. When the thickness of the substrate layer 121 is less than 3μm, the substrate layer 121 is too thin, reducing its ability to block copper ions. When the thickness of the substrate layer 121 is greater than 6μm, it increases the manufacturing cost and also increases the overall thickness of the first electrode 120, thereby increasing the thickness of the resistor 100, which is detrimental to the miniaturization of the resistor 100.

[0045] In some embodiments, the weld layer 122 is made of gold. Compared to copper, gold has better welding performance, improving the overall resistance accuracy and stability of the resistor 100.

[0046] In some embodiments, the thickness of the weld layer 122 is D5, satisfying: 0.03 ≤ D5 ≤ 0.1 μm. Specifically, D3 can be 0.03 μm, 0.035 μm, 0.04 μm, 0.045 μm, 0.05 μm, 0.055 μm, 0.06 μm, 0.065 μm, 0.07 μm, 0.075 μm, 0.08 μm, 0.085 μm, 0.09 μm, 0.095 μm, 0.1 μm, etc., and is not limited to the values ​​in the examples. When the thickness of the weld layer 122 is less than 0.03 μm, the weld layer 122 is too thin, reducing the weld stability. When the thickness of the solder layer 122 is greater than 0.1μm, the manufacturing cost increases. An excessively thick gold layer may cause "gold brittleness" (the solder joint becomes brittle), which also increases the overall thickness of the first electrode 120, thereby increasing the thickness of the resistor 100, which is not conducive to the miniaturization of the resistor 100.

[0047] like Figure 1 As shown, when the first electrode 120 layer includes a base layer 121, an isolation layer 123, and a solder layer 122.

[0048] The base layer 121 is connected to the resistor 110. The isolation layer 123 is disposed on the side of the base layer 121 away from the resistor 110, and the solder layer 122 is disposed on the side of the isolation layer 123 away from the resistor 110. The base layer 121 acts as a buffer zone between the resistor 110 and the solder layer 122, preventing copper ions in the resistor 110 from diffusing into the isolation layer 123 and the solder layer 122, thereby improving the stability of the soldering.

[0049] In one embodiment, the substrate 121 is made of nickel.

[0050] In some embodiments, the thickness of the substrate layer 121 is D1, satisfying: 3μm ≤ D1 ≤ 6μm. Specifically, D1 can be 3μm, 3.2μm, 3.4μm, 3.6μm, 3.8μm, 4μm, 4.2μm, 4.4μm, 4.6μm, 4.8μm, 5μm, 5.2μm, 5.4μm, 5.6μm, 5.8μm, 6μm, etc., and is not limited to the values ​​in the examples. When the thickness of the substrate layer 121 is less than 3μm, the substrate layer 121 is too thin, reducing its ability to block copper ions. When the thickness of the substrate layer 121 is greater than 6μm, it increases the manufacturing cost and also increases the overall thickness of the first electrode 120, thereby increasing the thickness of the resistor 100, which is detrimental to the miniaturization of the resistor 100.

[0051] In some embodiments, the weld layer 122 is made of gold. Compared to copper, gold has better welding performance, improving the overall resistance accuracy and stability of the resistor 100.

[0052] In some embodiments, the thickness of the weld layer 122 is D3, satisfying: 0.03 ≤ D3 ≤ 0.1 μm. Specifically, D3 can be 0.03 μm, 0.035 μm, 0.04 μm, 0.045 μm, 0.05 μm, 0.055 μm, 0.06 μm, 0.065 μm, 0.07 μm, 0.075 μm, 0.08 μm, 0.085 μm, 0.09 μm, 0.095 μm, 0.1 μm, etc., and is not limited to the values ​​in the examples. When the thickness of the weld layer 122 is less than 0.03 μm, the weld layer 122 is too thin, reducing the weld stability. When the thickness of the solder layer 122 is greater than 0.1μm, the manufacturing cost increases. An excessively thick gold layer may cause "gold brittleness" (the solder joint becomes brittle), which also increases the overall thickness of the first electrode 120, thereby increasing the thickness of the resistor 100, which is not conducive to the miniaturization of the resistor 100.

[0053] The isolation layer 123 is used to separate the gold layer and the tin layer, effectively preventing nickel from diffusing into the gold layer and avoiding the "black nickel" problem (poor soldering caused by nickel oxidation).

[0054] In some embodiments, the isolation layer 123 is made of palladium. The thickness of the isolation layer 123 is D2, satisfying: 0.05 ≤ D2 ≤ 0.15 μm. Specifically, D2 is 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.11 μm, 0.12 μm, 0.13 μm, 0.14 μm, 0.15 μm, etc., and is not limited to the values ​​in the examples. When the thickness of the isolation layer 123 is less than 0.05 μm, the isolation layer 123 is too thin, reducing the isolation stability. When the thickness of the isolation layer 123 is greater than 0.15 μm, it increases the manufacturing cost and also increases the overall thickness of the first electrode 120, thereby increasing the thickness of the resistor 100, which is not conducive to the miniaturization of the resistor 100.

[0055] It should be noted that when the first electrode 120 layer includes a base layer 121 and a solder layer 122, or when the first electrode 120 includes a base layer 121, an isolation layer 123 and a solder layer 122, the thickness of the first electrode 120 is lower than the thickness when the first electrode 120 uses a copper layer and / or a nickel layer.

[0056] In some embodiments, the thickness of the first electrode 120 and the thickness of the second electrode 130 are the same in the direction opposite to the first surface 111. The thickness of the first electrode 120 layer is D, which satisfies: 3μm≤D≤20μm. Specifically, D is 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, etc., and is not limited to the values ​​in the examples.

[0057] In some embodiments, the passivation layer 140 is an oxide layer, a polymer layer, or an insulating coating.

[0058] When the passivation layer 140 is an oxide layer, the oxide is silicon dioxide, aluminum oxide, or nickel / chromium oxide.

[0059] When the passivation layer 140 is a polymer layer, the polymer is epoxy resin, polyimide, silicone resin or parylene.

[0060] When the passivation layer 140 is a coating, the coating is a silicon nitride coating or a ceramic coating.

[0061] This application also provides a battery assembly, including a resistor 100, a protection board, and a battery cell as described in any of the above embodiments, wherein the resistor 100 is electrically connected to the protection board, and the protection board is electrically connected to the battery cell.

[0062] The protection board has a connection part that is electrically connected to the tabs of the battery cells, and the resistor 100 is soldered to the protection board. By reducing the thickness of the resistor 100, when the protection board is arranged parallel to the battery cells, the volume of the battery assembly in the length direction of the battery cells can be reduced; when the protection board is arranged perpendicular to the battery cells, the volume of the battery assembly in the thickness direction of the battery cells can be reduced, making the battery assembly thinner and lighter, and increasing the energy density of the battery assembly.

[0063] This application also provides a method for fabricating a resistor, the method comprising: Step S10: Obtain resistor 110 and cover the surface of resistor 110 with a film.

[0064] like Figure 5 As shown, photosensitive adhesive 200 is printed on the first surface 111 of the resistor 110.

[0065] Step S20: The required electrode size is obtained by exposure and development.

[0066] like Figure 6 As shown, a mask is placed above photosensitive emulsion 200 and irradiated with light of a specific wavelength, causing the mask pattern to transfer onto the photosensitive emulsion 200. After exposure, the chemical properties of the photosensitive emulsion 200 change.

[0067] like Figure 6 As shown, the exposed areas (positive photomask) or unexposed areas (negative photomask) are removed by using a developing solution to obtain a pattern that matches the mask pattern.

[0068] Step S30: Etch to create a window.

[0069] like Figure 6As shown, dry etching (plasma etching) or wet etching (chemical solution) is used, and photosensitive adhesive 200 is used as a mask to protect the resistive region 1111 covered by it from being etched, while the unprotected electrode region 1112 is removed to form the desired structure.

[0070] After etching is completed, the residual photosensitive adhesive 200 in electrode area 1112 is removed.

[0071] Step S40: Fabricate electrodes.

[0072] like Figure 7 As shown, copper is plated in electrode region 1112 to form a first electrode 120 and a second electrode 130; Alternatively, nickel plating can be performed in electrode region 1112 to form a first electrode 120 and a second electrode 130. Alternatively, copper may be plated first in electrode region 1112 and then nickel to form first electrode 120 and second electrode 130. Alternatively, nickel can be electrolessly plated in electrode region 1112, followed by palladium electroless plating, and finally gold immersion to form the first electrode 120 and the second electrode 130. Alternatively, nickel can be electrolessly plated in electrode region 1112, followed by gold immersion to form the first electrode 120 and the second electrode 130.

[0073] Step S50: Passivation treatment.

[0074] like Figure 1 , Figure 2 , Figure 3 or Figure 4 As shown, first remove the remaining 200g of photosensitive emulsion; Then, use an acidic degreasing agent to degrease the surface of resistor 110 at 25-35℃. Finally, a passivating agent is used to passivate the resistive region 1111 of the first surface 111 and the second surface 112 at 40-50°C for 3-5 minutes.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0076] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A resistor, characterized in that, It includes a resistor (110), a first electrode (120), a second electrode (130), and a passivation layer (140); wherein the resistor (110) has a first surface (111) and a second surface (112) disposed opposite to each other, the first surface (111) has a resistive region (1111) and two electrode regions (1112), the first electrode (120) is disposed in one of the electrode regions (1112), the second electrode (130) is disposed in the other electrode region (1112), and the passivation layer (140) covers the resistive region (1111) and the second surface (112).

2. The resistor according to claim 1, characterized in that, The first electrode (120) includes: Basal layer (121); Isolation layer (123); A solder layer (122) is provided, wherein the base layer (121) is connected to the resistor (110), and the base layer (121) is used to prevent copper ions in the resistor (100) layer from diffusing toward the solder layer (122); an isolation layer (123) is provided on the side of the base layer (121) away from the resistor (110), and the isolation layer (123) is used to prevent the base layer (121) from reacting with the solder layer (122); the solder layer (122) is provided on the side of the isolation layer (123) away from the resistor (110).

3. The resistor according to claim 2, characterized in that, The base layer (121) is made of nickel; The isolation layer (123) is made of palladium; The weld layer (122) is made of gold.

4. The resistor according to claim 3, characterized in that, The thickness of the base layer (121) is D1, which satisfies: 3μm≤D1≤6μm; The thickness of the isolation layer (123) is D2, which satisfies: 0.05≤D2≤0.15μm; The thickness of the weld layer (122) is D3, which satisfies: 0.03≤D3≤0.1μm.

5. The resistor according to claim 1, characterized in that, The first electrode (120) includes: Basal layer (121); A solder layer (122) is provided on the side of the base layer (121) away from the resistor (110). The base layer (121) is connected to the resistor (110). The base layer (121) is used to prevent copper ions in the resistor (100) layer from diffusing towards the solder layer (122).

6. The resistor according to claim 5, characterized in that, The base layer (121) is made of nickel; The weld layer (122) is made of gold.

7. The resistor according to claim 6, characterized in that, The thickness of the base layer (121) is D4, which satisfies: 3μm≤D4≤6μm; The thickness of the weld layer (122) is D5, which satisfies: 0.03≤D5≤0.1μm.

8. The resistor according to claim 1, characterized in that, The first electrode (120) and the second electrode (130) are made of copper; Alternatively, the first electrode (120) and the second electrode (130) may be made of nickel; Alternatively, the first electrode (120) and the second electrode (130) have the same structure. The first electrode (120) includes a copper layer and a nickel layer. The copper layer is disposed on the first surface (111) of the resistor (110), and the nickel layer is disposed on the surface of the copper layer away from the resistor (110).

9. The resistor according to any one of claims 1 to 8, characterized in that, The first electrode (120) layer and the second electrode (130) layer have the same thickness, and the thickness of the first electrode (120) layer is D, satisfying: 3≤D≤20μm; and / or The passivation layer (140) is an oxide layer, a polymer layer, or an insulating coating.

10. A battery assembly, characterized in that, The device includes a resistor (100) as described in any one of claims 1 to 9, a protection board, and a battery cell, wherein the resistor (100) is electrically connected to the protection board, and the protection board is electrically connected to the battery cell.

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