Flexible equipotential wire bar

Abstract

The utility model relates to a flexible equipotential wire bar, which comprises a flexible printed circuit (FPC) wire bar and a plurality of equipotential structures arranged on the FPC wire bar at intervals, each equipotential structure comprises an equipotential circuit and two FPC bonding pads which are formed on the FPC wire bar, and two equipotential sheets which are respectively welded on the two FPC bonding pads, the two FPC bonding pads are connected to the two ends of the equipotential circuit, the hardness of the equipotential piece is larger than that of the FPC wire bar, and after the equipotential piece is welded and fixed, mechanical vibration, assembly stress or deformation caused by external force in the using process can be effectively resisted. The equipotential wire bar has higher mechanical strength, more stable electrical connection and better thermal management capability in a new energy battery system, and meanwhile, process feasibility and cost effectiveness are taken into account, and potential consistency among the battery cell modules is ensured.

Description

Technical Field

[0001] This utility model relates to the field of equipotential structure technology, specifically to a flexible equipotential line bus. Background Technology

[0002] Currently, in the new energy lithium battery industry, the battery pack, as a high-voltage component, is crucial for ensuring equipotential bonding. Equipotential bonding is defined as the minimization of the potential difference between the exposed conductive parts of electrical equipment. With equipotential bonding, even if the insulation between the positive or negative terminal of the battery module and the battery pack casing fails due to a fault, the same potential is achieved through equipotential bonding. This ensures that no current is generated when a person comes into contact with certain metal parts of the vehicle, and the person remains safe inside the vehicle. To achieve potential balance in the battery pack, a new type of equipotential bonding method is the use of flexible equipotential boards (FPCs) embedded in the circuit design. FPCs are widely used in circuit board products, especially due to their thinness, flexibility, rollability, low voltage, low power consumption, and low power requirements. Many automotive battery modules on the market also use FPC equipotential boards to replace traditional wire harness equipotential bonding methods. This type of FPC equipotential board uses an integral etching process to form multiple connecting pieces on both sides. These connecting pieces are then soldered to the battery module to achieve equipotential bonding in the battery pack. However, this type of FPC equipotential board also has the following problems in actual use: because the FPC equipotential board is thin and flexible, the connecting pieces lack rigidity, making them prone to warping, twisting, and misalignment. Frequent bending can even lead to fatigue fracture of the connecting pieces, preventing them from being stably and reliably attached to the preset position on the battery module. This directly affects the welding quality and efficiency between the FPC equipotential board and the battery module. Utility Model Content

[0003] In view of this, the technical problem to be solved by this utility model is to overcome the problem that the FPC equipotential plate in the prior art is very soft and the connecting piece on it is not hard enough, which makes the connecting piece easy to warp, twist and misalign, thereby affecting the welding quality and working efficiency between the FPC equipotential plate and the battery module.

[0004] To solve the above-mentioned technical problems, this utility model provides a flexible equipotential bonding bus, including an FPC bus and multiple sets of equipotential structures spaced apart on the FPC bus. Each set of equipotential structures includes an equipotential line formed on the FPC bus and two FPC pads, as well as two equipotential plates respectively soldered on the two FPC pads. The two FPC pads are connected to the two ends of the equipotential line. The two equipotential plates are rigid sheet structures and extend outward from the edge of the FPC bus for connecting the battery cell module. The hardness of the equipotential plates is greater than the hardness of the FPC bus.

[0005] As a preferred embodiment, the FPC busbar is an aluminum-based FPC busbar, and the equipotential bonding sheet is an aluminum sheet structure welded to the aluminum-based FPC busbar.

[0006] As a preferred embodiment, the FPC busbar is a copper-based FPC busbar, and the equipotential bonding sheet is a copper sheet structure soldered onto the copper-based FPC busbar.

[0007] As a preferred embodiment, the thickness of the equipotential sheet is 0.2-1 mm.

[0008] As a preferred embodiment, the FPC busbar is covered with an insulating protective film on both sides, and the insulating protective film has a welding window corresponding to the FPC pad position. One end of the equipotential bonding sheet is welded to the FPC pad at the welding window.

[0009] As a preferred embodiment, the two equipotential plates of each equipotential structure extend to the two sides or the same side of the FPC busbar, and the equipotential plates are arranged in a bent structure.

[0010] As a preferred embodiment, the FPC busbar includes multiple FPC unit sections distributed at intervals along its length. Each of the multiple FPC unit sections is provided with a set of equipotential structures. An FPC connection section is provided between two adjacent FPC unit sections. The middle part of the FPC connection section is a hollow structure, and two notches are provided on its two sides.

[0011] As a preferred embodiment, each FPC unit is provided with a bent and extended equipotential line and two FPC pads connected to both ends of the equipotential line, as well as two equipotential plates soldered on the two FPC pads, and a fuse line is connected in series along the extension path of the equipotential line.

[0012] As a preferred embodiment, the equipotential bonding circuit and the fuse circuit are integrally formed in the FPC unit, and the wire diameter of the fuse circuit is smaller than that of the equipotential bonding circuit.

[0013] As a preferred embodiment, the FPC unit is provided with two strip slots, and two FPC pads are distributed on both sides of the two strip slots. The equipotential line bends and extends between the two strip slots to connect the two FPC pads.

[0014] Compared with the prior art, the technical solution of this utility model has the following advantages:

[0015] 1. The flexible equipotential bonding busbar provided by this utility model fixes the metal equipotential bonding sheet to the FPC busbar by welding. Compared with the traditional one-piece molded soft equipotential bonding sheet, it mainly brings the following advantages: First, it improves the structural strength and stability. This metal equipotential bonding sheet has higher hardness and can effectively resist mechanical vibration, assembly stress, or deformation caused by external forces during use after welding. It avoids poor contact or short circuit risks caused by bending or misalignment, or fatigue fracture of the equipotential bonding sheet caused by frequent bending, and has a good anti-bending and anti-misalignment effect. Second, it also optimizes the electrical performance of the product. The hardness of this metal equipotential bonding sheet and welding fixation can maintain the stable shape of the current path, avoid uneven current distribution caused by deformation of soft materials, and improve the current sharing effect of the battery module. Third, it improves the welding quality and working efficiency between the FPC equipotential bonding busbar and the cell module. This design is conducive to improving the safety and life of the battery module.

[0016] 2. In the flexible equipotential bonding pad provided by this utility model, the function of the flexible equipotential bonding pad is to ensure the potential consistency between each cell module and prevent excessive voltage difference from affecting battery performance or safety. By welding a metal equipotential sheet with higher hardness to the equipotential bonding pad, the FPC equipotential bonding pad achieves higher mechanical strength, more stable electrical connection, and better thermal management capability in new energy battery systems. At the same time, it takes into account process feasibility and cost-effectiveness, and can be well applied to scenarios with stringent requirements for reliability and durability, such as electric vehicles and energy storage systems.

[0017] 3. In the flexible equipotential bonding busbar provided by this utility model, the substrates of the equipotential bonding sheet and the FPC equipotential bonding busbar are uniformly made of aluminum or copper. The advantage of this design is that when the metal equipotential bonding sheet and the FPC substrate are the same metal (aluminum or copper), their conductivity and electron migration characteristics are consistent, reducing contact resistance, reducing mechanical stress, improving heat dissipation performance, simplifying the welding process, and making it reliable and economical. By designing a unified metal material, the advantages of aluminum or copper can be maximized, while avoiding compatibility issues of combining dissimilar materials. Such an optimized design has significant advantages in terms of performance, process, and cost.

[0018] 4. In the flexible equipotential line provided by this utility model, the FPC line includes multiple FPC connecting parts connected between multiple FPC unit parts. The middle part of this FPC connecting part has a hollow structure, and two notches are provided on both sides. This can absorb the mechanical stress caused by vibration, temperature change, and battery expansion / contraction during the installation or use of the FPC line. In addition, according to the installation length requirements of the FPC line, the FPC connecting part can be cut at the corresponding notch position, thereby meeting the installation and connection requirements of FPC line of different lengths.

[0019] 5. The flexible equipotential bonding busbar provided by this utility model, by designing bent and extended equipotential lines and series fuse lines in the FPC equipotential bonding busbar, achieves high reliability connection and active safety protection of the new energy battery system in dynamic environments through mechanical flexibility and integrated electrical protection design. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the flexible equipotential line provided by this utility model;

[0022] Figure 2 This is a partially enlarged structural diagram of the flexible equipotential line bus of this utility model;

[0023] Figure 3 for Figure 2 The diagram shows the structure of the flexible equipotential bonding array with the equipotential bonding sheet hidden.

[0024] Explanation of reference numerals in the attached drawings: 1. FPC busbar; 11. FPC unit section; 12. FPC connection section; 13. Strip slot; 14. Notch slot; 2. Equipotential bonding sheet; 3. Equipotential bonding line; 4. FPC pad; 5. Fuse line; 6. Soldering window. Detailed Implementation

[0025] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] In the description of this utility model, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0029] Example

[0030] This utility model provides, for example Figures 1-3 The flexible equipotential bonding busbar includes an FPC busbar 1 and multiple sets of equipotential structures spaced apart on the FPC busbar 1. Each set of equipotential structures includes an equipotential line 3 formed on the FPC busbar 1 and two FPC pads 4, as well as two equipotential plates 2 respectively soldered on the two FPC pads 4. The equipotential plates 2 are metal equipotential plates 2. The two FPC pads 4 are connected to the two ends of the equipotential line 3. The two equipotential plates 2 are rigid sheet structures and extend outward from the edge of the FPC busbar 1 for connecting the battery cell module. The hardness of the equipotential plates 2 is greater than the hardness of the FPC busbar 1.

[0031] The above-described implementation method is the core technical solution of this embodiment. The metal equipotential bonding sheet 2 is fixed to the FPC busbar 1 by welding. Compared with the traditional one-piece molded soft equipotential bonding sheet 2, it mainly brings the following advantages: First, it improves the structural strength and stability. This metal equipotential bonding sheet has higher hardness and can effectively resist mechanical vibration, assembly stress, or deformation caused by external forces during use after welding. It avoids poor contact or short circuit risks caused by bending or misalignment, or fatigue fracture of the equipotential bonding sheet caused by frequent bending. It has a good anti-bending and anti-misalignment effect. Second, it also optimizes the electrical performance of the product. The hardness of this metal equipotential bonding sheet and welding fixation can maintain the stable shape of the current path and avoid uneven current distribution caused by deformation of soft materials, thus improving the current sharing effect of the battery module. Third, it improves the welding quality and working efficiency between the FPC equipotential bonding sheet and the cell module. This flexible equipotential bonding sheet design is conducive to improving the safety and life of the battery module.

[0032] The following is combined Figure 1-3 The specific arrangement of the FPC busbar and equipotential bonding plate is described in detail below:

[0033] The FPC busbar 1 is an aluminum-based FPC busbar 1, and the equipotential bonding sheet 2 is an aluminum sheet structure (aluminum potential sheet) welded to the aluminum-based FPC busbar 1. The thickness of the aluminum sheet structure is 0.2-1mm. Obviously, the hardness of this aluminum sheet structure is greater than that of the aluminum-based FPC busbar 1. This design has the following advantages: First, the aluminum-based FPC busbar 1 and the aluminum sheet structure can be ultrasonically welded or laser welded. Since the oxidation characteristics of the same metal are consistent, the aluminum potential sheet and the aluminum-based FPC busbar are directly welded to form a metallurgical bond, resulting in lower contact resistance and higher consistency, reducing energy loss and local heat generation, and improving the overall efficiency of the battery system. Second, the welded and fixed aluminum potential sheet can effectively resist mechanical vibration, assembly stress, or deformation caused by external forces during use, and has the functions of bending resistance and anti-displacement. Third, this aluminum potential sheet can serve as a heat dissipation medium, quickly dissipating heat from the FPC through the welding point, avoiding excessive local temperature that could affect battery life or cause thermal runaway. Furthermore, this aluminum-based FPC busbar is lightweight (compared to copper) and more flexible, making it suitable for complex spatial layouts (such as irregularly shaped battery packs) and for scenarios with high energy density and range requirements, such as electric vehicles.

[0034] As an alternative to the aforementioned FPC busbar 1 and equipotential bonding plate 2, the FPC busbar 1 is a copper-based FPC busbar 1, and the equipotential bonding plate 2 is a copper sheet structure welded to the copper-based FPC busbar 1. The thickness of the copper sheet structure is 0.2-1mm. The hardness of this copper busbar structure is greater than that of the copper-based FPC busbar 1. After welding and fixing, the copper equipotential bonding plate can effectively resist mechanical vibration, assembly stress, or deformation caused by external forces during use. It has the functions of bending resistance and anti-displacement, ensuring the efficiency of product welding. The copper equipotential bonding plate can also serve as a heat dissipation medium, quickly dissipating heat from the FPC through the welding points, avoiding excessive local temperature that could affect battery life or cause thermal runaway. In addition, this copper-based FPC busbar 1 supports finer circuit designs, is suitable for high-density integrated modules, has excellent conductivity, and is suitable for high-power battery modules (such as energy storage systems or fast charging equipment). Furthermore, the copper-based FPC busbar has higher mechanical strength, better vibration and impact resistance, and is suitable for laser welding or thermocompression welding. The process is mature and the cost is controllable.

[0035] In summary, using aluminum or copper as the substrate for both the equipotential bonding sheet 2 and the FPC equipotential line busbar (i.e., aluminum sheet structure with aluminum substrate FPC, copper sheet structure with copper substrate FPC) offers the following advantages: When the metal equipotential bonding sheet and the FPC substrate are the same metal (aluminum or copper), their conductivity and electron migration characteristics are consistent, reducing contact resistance, minimizing mechanical stress, improving heat dissipation, simplifying the welding process, and making the design reliable and economical. By using a unified metal material design, the advantages of aluminum or copper can be maximized, while avoiding compatibility issues associated with different material combinations. This unified metal material design offers significant advantages in terms of performance, process, and cost.

[0036] The FPC busbar 1 is covered with an insulating protective film on both sides. This film effectively protects the aluminum or copper substrate from exposure to air, preventing oxidation and static electricity, thus providing insulation and protection. Figure 3 As shown, the insulating protective film has a welding window 6 at the position of the FPC pad 4, and the rest of the FPC busbar 1 is effectively covered by the insulating protective film. One end of the equipotential bonding sheet 2 is welded to the FPC pad 4 at the welding window 6, and the other end of the equipotential bonding sheet 2 is extended and attached to the cell module to achieve welding, thereby ensuring that the potential between each cell module is consistent. Specifically, the two equipotential bonding sheets 2 of each equipotential structure are respectively extended and set on both sides or the same side of the FPC busbar 1. The equipotential bonding sheet 2 is set with a bent structure according to the position and shape of the cell module to adapt to the installation and connection of the cell module.

[0037] In this embodiment, reference Figure 1 and Figure 3 The FPC busbar 1 includes multiple FPC unit sections 11 spaced apart along its length. Each FPC unit section 11 is provided with a set of equipotential structures. An FPC connection section 12 is provided between two adjacent FPC unit sections 11, that is, two adjacent FPC unit sections 11 are connected by the FPC connection section 12. The middle part of the FPC connection section 12 is a hollow structure, and two notches 14 are provided on both sides. This can absorb the mechanical stress generated by vibration, temperature change, and battery expansion / contraction during the installation or use of the FPC busbar 1. In addition, according to the installation length requirements of the FPC equipotential busbar, the FPC connection section 12 can be cut at the corresponding notch 14 position to meet the installation and connection requirements of FPC equipotential busbars of different lengths.

[0038] In a further preferred configuration, each FPC unit 11 is provided with a bent and extended equipotential line 3 and two FPC pads 4 connected to both ends of the equipotential line 3, as well as two equipotential bonding pads 2 soldered to the two FPC pads 4. Specifically, the FPC unit 11 is provided with two strip-shaped slots 13, and the two FPC pads 4 are distributed on both sides of the two strip-shaped slots 13. The equipotential line 3 bends and extends between the two strip-shaped slots 13 to connect the two FPC pads 4. With this structural configuration, each FPC unit on the FPC busbar 1 is provided with a equipotential line 3, an equipotential bonding pad 4, and two equipotential bonding pads 2 soldered to the two FPC pads 4. The equipotential structure formed by the C pad and the equipotential bonding pad 2 extends and bends the equipotential line 3 in each FPC unit. This allows it to adapt to mechanical deformation and improve durability. By increasing flexible redundancy, it reduces local stress concentration and significantly improves the fatigue resistance of the FPC busbar 1 in dynamic environments (such as the bumpy conditions of electric vehicles). In addition, this design of the extended and bendable equipotential line 3 can flexibly adapt to narrow or irregular spaces, ensuring the integrity of the equipotential connection to match the complex spatial layout of the FPC busbar. At the same time, by increasing the conductor length or adjusting the path, it optimizes the current distribution, reduces the risk of local overheating, and improves the product's performance.

[0039] To ensure circuit safety of flexible equipotential bonding lines under complex operating conditions, combined with Figure 2-3 As shown, a fuse line 5 is connected in series along the extension path of the equipotential bonding line 3. The equipotential bonding line 3 and the fuse line 5 are integrally formed in the FPC unit 11, and the wire diameter of the fuse line 5 is smaller than that of the equipotential bonding line 3. With this structure, when the battery module experiences an overcurrent due to abnormal conditions such as short circuits, overcharging, or external impacts, the fuse quickly melts, cutting off the fault circuit and preventing thermal runaway or chain reactions. This provides overcurrent protection and fault isolation. The fuse's melting parameters can be customized according to the battery system's rated current and safety requirements to ensure the accuracy and timeliness of the protection action. In summary, the flexible equipotential bonding line design of this embodiment, with its bent and extended equipotential bonding line 3 and series-connected fuse line 5, achieves highly reliable connection and active safety protection for the new energy battery system in dynamic environments through mechanical flexibility and integrated electrical protection.

[0040] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A flexible equipotential busbar, characterized in that, The FPC wire row (1) is an aluminum substrate FPC wire row (1), and the equipotential sheet (2) is an aluminum sheet structure welded to the aluminum substrate FPC wire row (1).

2. The flexible equipotential strip of claim 1, wherein: The FPC wire row (1) is a copper substrate FPC wire row (1), and the equipotential sheet (2) is a copper sheet structure welded to the copper substrate FPC wire row (1).

3. The flexible equipotential strip of claim 1, wherein: The thickness of the equipotential sheet (2) is 0.2-1mm.

4. The flexible equipotential strip according to any one of claims 1-3, characterized in that: The FPC wire row (1) is covered with an insulating protective film on both front and back surfaces, the insulating protective film is provided with a welding window (6) corresponding to the position of the FPC pad (4), and one end of the equipotential sheet (2) is welded to the FPC pad (4) at the welding window (6).

5. The flexible equipotential strip of claim 1, wherein: The two equipotential sheets (2) of each equipotential structure are respectively arranged on the two side edges or the same side edge of the FPC wire row (1), and the equipotential sheet (2) is arranged in a bending structure.

6. The flexible equipotential strip of claim 5, wherein: The FPC wire row (1) includes a plurality of FPC unit parts (11) arranged along the length direction, each FPC unit part (11) is provided with a group of equipotential structures, and an FPC connecting part (12) is arranged between two adjacent FPC unit parts (11), the middle part of the FPC connecting part (12) is a hollow structure, and two notched grooves (14) are respectively arranged on both sides of the FPC connecting part (12).

7. The flexible equipotential strip of claim 1, wherein: Each FPC unit part (11) is provided with a bending and extending equipotential line (3), two FPC pads (4) connected to both ends of the equipotential line (3), and two equipotential sheets (2) welded to the two FPC pads (4), and a fuse line (5) is arranged in series on the extension path of the equipotential line (3).

8. The flexible equipotential strip of claim 7, wherein: The equipotential line (3) and the fuse line (5) are integrally formed on the FPC unit part (11), and the wire diameter of the fuse line (5) is smaller than that of the equipotential line (3).

9. The flexible equipotential strip of claim 8, wherein: The FPC unit part (11) is provided with two strip-shaped air grooves (13), and the two FPC pads (4) are arranged on both sides of the two strip-shaped air grooves (13), and the equipotential line (3) is bent and extended from between the two strip-shaped air grooves to connect the two FPC pads (4).

10. The flexible equipotential strip according to any one of claims 7-9, characterized in that: ​

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