Conductive connection structure and production and processing technology thereof

Abstract

The invention provides a conductive connection structure and a production and processing technology thereof, and belongs to the technical field of flexible connection conductive sheets. Comprising a flexible connection conducting strip formed by stacking a plurality of conducting sheets, the two ends of the flexible connection conducting strip are welded and fixed, connecting parts are formed at the welding positions of the two ends of the flexible connection conducting strip, and the middle flexible connection position of the flexible connection conducting strip is in a bent shape. Raw materials are cut into large sheet raw materials, after the large sheet raw materials are stacked together, interlayer tight bonding is achieved on the periphery through thermocompression welding, then primary punching is carried out, the thermocompression welding parts on the two sides form a plurality of semi-finished products of the flexible connection conducting strip, and at the moment, the periphery is in a closed state through thermocompression welding; after electroplating, secondary punching is carried out to form a plurality of flexible connection conducting strips, and the processing mode does not need to wind a protective adhesive tape during electroplating, so that electroplating materials cannot enter the middle areas of the flexible connection conducting strips, the stability of products is improved, and the processing efficiency can be improved.

Description

Technical Field

[0001] This invention belongs to the field of flexible conductive sheet technology, specifically relating to a conductive connection structure and its manufacturing process. Background Technology

[0002] Flexible conductive sheets are conductive components that enable electrical connections and possess a certain degree of flexibility. They are typically made of highly conductive metals such as copper and aluminum. Flexible conductive sheets have a wide range of applications across various industries. In the new energy vehicle industry, they are primarily used for connecting battery modules, adapting to volume changes during charging and discharging to ensure the efficient and stable operation of the battery system. In the power industry, they are commonly used in transformers, switchgear, and other equipment, serving as both conductive and mechanical buffers to improve the reliability and safety of power equipment. This effectively compensates for displacement caused by equipment vibration, thermal expansion and contraction, and other factors, ensuring the stability of the electrical connection. The current production process for flexible conductive sheets requires individual welding and fixing before electroplating. Since these sheets are composed of multiple layers of thin sheets, the central area is susceptible to electroplating contamination after welding. This contamination affects the sheet's toughness and reduces its performance. To prevent this, a common method is to wrap protective tape around the sheet before electroplating. However, this method has several drawbacks. It is cumbersome, requiring significant manpower and time. Furthermore, ensuring the tape's uniformity and tightness during wrapping is difficult, leading to overlapping or excessive gaps that compromise protection. Additionally, the protective tape may be damaged during electroplating due to corrosion from the plating solution or mechanical friction. If damaged, the electroplating material can easily enter the central area of ​​the flexible conductive sheet, increasing product instability. Summary of the Invention

[0003] (1) Technical problems to be solved In view of the shortcomings of the prior art, the purpose of this invention is to provide a conductive connection structure and its manufacturing process, so as to solve the problem that the existing flexible conductive sheet is formed by stacking multiple thin sheets, welding and electroplating them one by one, and wrapping protective tape in the middle, which is not only cumbersome to operate, but also increases the instability of the product.

[0004] (2) Technical solution To solve the above-mentioned technical problems, the present invention provides a conductive connection structure comprising a flexible conductive sheet composed of multiple conductive sheets stacked on top of each other. The two ends of the flexible conductive sheet are welded and fixed, and the welded ends of the flexible conductive sheet form a connection portion. The flexible connection portion in the middle of the flexible conductive sheet is bent, and the flexible connection portion in the middle of the flexible conductive sheet is covered with an insulating tube. The peel force of the conductive sheet is not less than 30N, the peel force in the middle of the conductive sheet is not less than 20N, and a connection through hole is provided at the end of the connection portion. The conductive connection structure is manufactured using a production process that includes sheet cutting, sheet welding, polishing, primary punching, electroplating, secondary punching, insulation tube fitting, bending and forming, and full inspection.

[0005] Preferably, the conductive sheet is made of T2 copper and has a thickness of 0.08-0.12 mm.

[0006] Preferably, the two ends of the flexible conductive sheet are fixed by thermoforming.

[0007] Preferably, the insulating tube is a heat-shrinkable insulating tube.

[0008] Preferably, the specific production and processing technology is as follows: Sheet cutting: Cut the raw materials into thin sheets according to the design dimensions, and then stack the multiple layers of thin sheets neatly together; Thin sheet welding: Hot-press welding is used to achieve tight bonding between the layers of multi-layer thin sheet materials to form a sheet material; Polishing: Grind and polish the hot-pressed welded parts of the sheet metal to make them free of bumps, pits and obvious scratches. One-time punching: The sheet metal is placed into a punching machine for one-time punching, so that multiple corresponding protrusions are formed on both sides of the hot-pressed welded part, and connecting through holes are punched at the ends of the protrusions. The length of the protrusions is less than the width of the hot-pressed welded part. Electroplating: Electroplating is performed on the surface of a sheet material to form a uniform and dense metal coating. Secondary punching: The sheet metal is placed into a punching machine for secondary punching, so that the protrusions on the corresponding parts on both sides are connected to form a flexible conductive sheet. Insulating tube fitting: Based on the size of the flexible conductive sheet, accurately measure and select a heat-shrinkable insulating tube with an inner diameter slightly larger than the outer diameter of the flexible conductive sheet to ensure that the insulating tube can be smoothly fitted and that it fits tightly against the flexible conductive sheet after shrinking. Bending and forming: Bending equipment is used to change the shape of the flexible conductive sheet to ensure that the bending angle and shape meet the design requirements and satisfy different installation environments; Full inspection: The appearance and dimensions of the flexible conductive sheet are inspected and processed to ensure that the surface of the flexible conductive sheet is smooth, flat, free of obvious scratches and cracks, and that the dimensions are consistent with the design drawings.

[0009] Preferably, the hot-pressed welding portion of the plate includes a first hot-pressed zone on both sides and a second hot-pressed zone on the other two sides. The width of the first hot-pressed zone is greater than the hot-pressed width of the second hot-pressed zone. The hot-pressed width of the first hot-pressed zone is not less than the length of the connecting portion. The protrusion is formed by punching the first hot-pressed zone.

[0010] Preferably, the corner of the hot-pressed welded portion of the plate is provided with a positioning hole.

[0011] Preferably, in the electroplating process, the metal plating layer is a nickel plating layer with a thickness of 3 μm, and the width of the second hot-pressing zone is 4.5-5.5 mm.

[0012] Preferably, the pressure for hot-press welding is 0.8-1.5 MPa, and the pressure is applied twice during hot-press welding.

[0013] Preferably, the first pressurization is at a pressure of % of the sheet material thickness, and the pressurization time is equal to the thickness of the sheet material. 10-15s, the second pressurization is at a certain percentage of the pressure; holding time: thickness of the sheet material. 20-30s.

[0014] (3) Beneficial effects Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the above solution, the raw materials are cut into large thin sheets, stacked together, and then hot-pressed and welded to achieve tight interlayer bonding. Then, a punching is performed to form a semi-finished product of multiple flexible conductive sheets from the hot-pressed welded parts on both sides. At this time, the sides are sealed by hot-pressing and welding. After electroplating, a second punching is performed to form multiple flexible conductive sheets. This processing method does not require wrapping protective tape during electroplating. Not only will the electroplating material not enter the central area of ​​the flexible conductive sheet, improving the stability of the product, but it can also improve processing efficiency. 2. In the above scheme, the multi-layer thin sheet material is pressure-welded in two stages. In the first stage of pressure application, the pressure rises to 30%. At this time, the microscopic protrusions between the thin sheet materials are first squeezed against each other, resulting in plastic deformation. The pressure at this stage can initially expel most of the air between the thin sheet materials, reducing the presence of bubbles and voids and mitigating their negative impact on the bonding strength. Then, the second stage of pressure application is carried out, with the pressure reaching 100%. As the pressure increases, the interatomic distance between the thin sheet materials further decreases, the interatomic interaction force is enhanced, and the diffusion rate accelerates. At this time, the areas that could not fully contact and bond in the first stage of pressure application are allowed to diffuse and fuse more fully under the action of the second pressure application, thereby filling the tiny gaps and weak points that may have existed after the first pressure application. This allows the multi-layer thin sheet materials to gradually achieve a tight bond at different stages, thereby improving the strength of the weld fixation. Attached Figure Description

[0015] Figure 1 This is a frontal cross-sectional view of the conductive connection structure.

[0016] Figure 2 For conductive connection structure Figure 1 A magnified structural diagram of point A in the middle.

[0017] Figure 3 This is a schematic diagram of the conductive connection structure from the right.

[0018] Figure 4 A schematic diagram of the sheet material structure used in the manufacturing process of conductive connection structures.

[0019] Figure 5 This is a schematic diagram of the stacked sheet material structure used in the manufacturing process of conductive connection structures.

[0020] Figure 6 This is a schematic diagram of a welded structure made of stacked thin sheet materials used in the manufacturing process of a conductive connection structure.

[0021] Figure 7 This is a schematic diagram of the post-weld punching process for manufacturing conductive connection structures.

[0022] Figure 8 This is a schematic diagram of the secondary punching process after electroplating in the manufacturing process of conductive connection structures. Figure 9 This is a schematic diagram of the side structure after secondary punching in the manufacturing process of the conductive connection structure.

[0023] Figure 10 This is a schematic diagram of the structure of an insulating tube used in the manufacturing process of a conductive connection structure.

[0024] Figure 11This is a schematic diagram of the bending structure used in the manufacturing process of a conductive connection structure.

[0025] The labels in the attached diagram are as follows: 1. Conductive sheet; 2. Flexible conductive sheet; 3. Connecting part; 4. Insulating tube; 5. Connecting through hole; 11. Sheet material; 12. Plate; 13. Protrusion; 14. Positioning hole; 1201. First hot pressing zone; 1202. Second hot pressing zone. Detailed Implementation

[0026] An embodiment of the present invention provides a conductive connection structure, comprising a flexible conductive sheet 2 composed of multiple conductive sheets 1 stacked on top of each other. The two ends of the flexible conductive sheet 2 are welded and fixed, and the welded ends of the flexible conductive sheet 2 form a connection part 3. The flexible connection part in the middle of the flexible conductive sheet 2 is bent. Since the middle of the flexible conductive sheet 2 is not welded and fixed to form a flexible connection, the flexible connection part can be bent to form a desired shape. The flexible connection part in the middle of the flexible conductive sheet 2 is covered with an insulating tube 4. The peel force of the conductive sheet 1 is not less than 30N, the peel force of the middle of the conductive sheet 1 is not less than 20N, and the end of the connection part 3 is provided with a connection through hole 5. The conductive connection structure is manufactured using a production process that includes thin sheet cutting, thin sheet welding, polishing, primary punching, electroplating, secondary punching, insulation tube fitting, bending and forming, and full inspection.

[0027] In order to improve the conductivity of the flexible conductive sheet 2 and give it good flexibility in the middle, in this embodiment, the conductive sheet 1 is made of T2 copper and the thickness of the conductive sheet 1 is 0.08-0.12mm.

[0028] To better fix the multiple conductive sheets 1 together, such as Figure 1 and Figure 3 As shown, in this embodiment, the two ends of the flexible conductive sheet 2 are fixed by thermo-press welding. Thermo-press welding is achieved by applying a certain pressure and heating at high temperature, which causes the molecules between the conductive sheets 1 to diffuse into each other, thereby achieving a firm connection. This welding method belongs to solid-state welding and will not cause the metal to melt. Therefore, it can maintain the original chemical composition and microstructure of the metal, thereby achieving sufficient interlayer fusion in the thermo-press welding area.

[0029] To facilitate the installation of the insulating tube 4, in this embodiment, the insulating tube 4 is a heat-shrinkable insulating tube. The heat-shrinkable tube shrinks by heating and tightly wraps the middle soft connection of the flexible conductive sheet 2 to form an insulating barrier. The heat-shrinkable tube has good insulation and corrosion resistance and can withstand temperatures above 125°C.

[0030] like Figure 4-11 As shown, in this embodiment, the specific production and processing technology is as follows: Sheet cutting: Cut the raw material into thin sheets 11 according to the design dimensions, and then stack multiple layers of thin sheets 11 neatly together, such as... Figure 4 As shown, the sheet material 11 is a large material, and after processing, multiple conductive sheets 1 can be formed laterally; Thin sheet welding: Hot pressing welding is used to achieve tight bonding between the layers of the multi-layer thin sheet material 11 to form a plate 12. The temperature parameters of hot pressing are existing technologies and will not be described in detail here. Polishing: Grind and polish the hot-pressed welded parts of the plate 12 to make the hot-pressed welded parts free of protrusions, pits and obvious scratches; One-time punching: The sheet metal 12 is placed into the punching equipment for one-time punching, so that multiple corresponding protrusions 13 are formed on both sides of the hot-pressed welded part, and connecting through holes 5 are punched at the ends of the protrusions 13. The length of the protrusions 13 is less than the width of the hot-pressed welded part. Electroplating: Electroplating is performed on the surface of the plate 12 to form a uniform and dense metal coating; Secondary punching: The sheet 12 is placed into the punching equipment for secondary punching, so that the protrusions 13 on the corresponding parts on both sides are connected to form a flexible conductive sheet 2. Insulating tube fitting: Based on the size of the flexible conductive sheet 2, accurately measure and select a heat-shrinkable insulating tube 4 with an inner diameter slightly larger than the outer diameter of the flexible conductive sheet 2 to ensure that the insulating tube 4 can be smoothly fitted and that the insulating tube 4 fits tightly with the flexible conductive sheet 2 after shrinking. Bending and forming: The shape of the flexible conductive sheet 2 is changed by bending equipment to ensure that the bending angle and shape meet the design requirements and satisfy different installation environments; Full inspection: Inspect and process the appearance and dimensions of the flexible conductive sheet 2 to ensure that the surface of the flexible conductive sheet 2 is smooth, flat, free of obvious scratches and cracks, and that the dimensions are consistent with the design drawings.

[0031] The technical solution provided by this invention involves cutting raw materials into large thin sheets 11, stacking them together, and then using hot-press welding to achieve tight interlayer bonding around the edges. A punching process is then performed to form multiple flexible conductive sheets 2 semi-finished products from the hot-press welded portions on both sides. At this point, the edges are sealed by hot-press welding. After electroplating, a second punching process is performed to form multiple flexible conductive sheets 2. This processing method eliminates the need to wrap protective tape during electroplating, preventing electroplating material from entering the central area of ​​the flexible conductive sheets 2, thus improving product stability and processing efficiency.

[0032] To reduce material usage and avoid excessive punching away of the hot-pressed welded parts, such as Figure 6 and Figure 7As shown, in this embodiment, the hot-press welding portion of the plate 12 includes a first hot-press area 1201 on both sides and a second hot-press area 1202 on the other two sides. The width of the first hot-press area 1201 is greater than the hot-press width of the second hot-press area 1202. The hot-press width of the first hot-press area 1201 is not less than the length of the connecting portion 3. The protrusion 13 is formed by punching the first hot-press area 1201.

[0033] like Figure 7 As shown, in this embodiment, a positioning hole 14 is provided at the corner of the hot-pressed welded part of the plate 12.

[0034] To improve service life, in this embodiment, the metal plating layer is a nickel plating layer with a thickness of 3 μm in the electroplating process, and the width of the second hot pressing zone 1202 is 4.5-5.5 mm. Copper-nickel plating can increase wear resistance, improve gloss, prevent metal corrosion, extend service life, and improve heat conduction efficiency. In addition, the second hot pressing zone 1202 is reasonably designed to prevent electroplating material from entering between the multilayer thin sheet raw materials 11 after hot pressing.

[0035] To ensure a secure fixation of both ends of the flexible conductive sheet 2, in this embodiment, the hot-press welding pressure is 0.8-1.5 MPa, and the pressure is applied in two stages during the hot-press welding process; the first application of pressure is 30% of the rated pressure, and the pressing time is equal to the thickness of the sheet material 11. 10-15s, meaning 10-15s of pressure is applied per mm thickness. The second pressure application is at 100% pressure. Holding time: Thickness of sheet material 11 20-30s, that is, apply pressure for 20-30s per mm thickness.

[0036] By applying pressure to the multi-layer thin sheet material 11 in two stages of welding, the pressure rises to 30% in the first stage. At this time, the microscopic protrusions between the thin sheet material 11 first squeeze each other and undergo plastic deformation. The pressure in this stage can initially expel most of the air between the thin sheet material 11, reduce the presence of bubbles and voids, and reduce their negative impact on the bonding strength. Then, the second stage of welding is carried out, and the pressure reaches 100% in this stage. As the pressure increases, the interatomic distance between the thin sheet material 11 further decreases, the interatomic interaction force is enhanced, and the diffusion rate is accelerated. At this time, the area that could not fully contact and bond in the first stage of welding is able to diffuse and fuse more fully under the action of the second stage of welding, thereby filling the small gaps and weak parts that may exist after the first stage of welding. This allows the multi-layer thin sheet material 11 to gradually achieve tight bonding in different stages, thereby improving the firmness of the welding fixation.

[0037] All technical features in this embodiment can be freely combined according to actual needs.

[0038] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present technical solution are within the protection scope of the present invention.

Claims

1. A conductive connection structure, characterized in that, The flexible conductive sheet (2) is composed of multiple conductive sheets (1) stacked together. The two ends of the flexible conductive sheet (2) are welded and fixed, and the welded ends of the flexible conductive sheet (2) form a connection part (3). The flexible connection part in the middle of the flexible conductive sheet (2) is bent, and the flexible connection part in the middle of the flexible conductive sheet (2) is covered with an insulating tube (4). The peeling force of the conductive sheet (1) is not less than 30N, the peeling force in the middle of the conductive sheet (1) is not less than 20N, and the end of the connection part (3) is provided with a connection through hole (5). The conductive connection structure is manufactured using a production process that includes sheet cutting, sheet welding, polishing, primary punching, electroplating, secondary punching, insulation tube fitting, bending and forming, and full inspection.

2. The conductive connection structure according to claim 1, characterized in that, The conductive sheet (1) is made of T2 copper and has a thickness of 0.08-0.12 mm.

3. The conductive connection structure according to claim 2, characterized in that, The two ends of the flexible conductive sheet (2) are fixed by hot-press welding.

4. The conductive connection structure according to claim 3, characterized in that, The insulating tube (4) is a heat-shrinkable insulating tube.

5. The manufacturing process of the conductive connection structure, characterized in that, The manufacturing process includes the conductive connection structure according to any one of claims 1-4, and is as follows: Thin sheet cutting: Cut the raw material into thin sheet material (11) according to the design size, and then stack the multiple layers of thin sheet material (11) neatly together; Thin sheet welding: Hot pressing welding is used to achieve tight interlayer bonding of the multi-layer thin sheet material (11) to form a plate (12). Polishing: The hot-pressed welded part of the plate (12) is ground and polished so that the hot-pressed welded part is free of protrusions, pits and obvious scratches; One-time punching: The plate (12) is placed into the punching equipment for one-time punching, so that the hot-pressed welding parts on both sides form multiple corresponding protrusions (13), and connecting through holes (5) are punched at the ends of the protrusions (13). The length of the protrusions (13) is less than the width of the hot-pressed welding parts. Electroplating: Electroplating is performed on the surface of the plate (12) to form a uniform and dense metal coating; Secondary punching: The plate (12) is placed into the punching equipment for secondary punching, so that the protrusions (13) of the corresponding parts on both sides are connected to form a soft connection conductive sheet (2). Insulating tube: Based on the size of the flexible conductive sheet (2), accurately measure and select a heat shrinkable insulating tube (4) with an inner diameter slightly larger than the outer diameter of the flexible conductive sheet (2) to ensure that the insulating tube (4) can be smoothly inserted and that the insulating tube (4) and the flexible conductive sheet (2) fit tightly after shrinking. Bending and forming: The shape of the flexible conductive sheet (2) is changed by bending equipment to ensure that the bending angle and shape meet the design requirements and satisfy different installation environments; Full inspection: The appearance and dimensions of the flexible conductive sheet (2) are inspected and processed to ensure that the surface of the flexible conductive sheet (2) is smooth, flat, without obvious scratches or cracks, and the dimensions are consistent with the design drawings.

6. The manufacturing process of the conductive connection structure according to claim 5, characterized in that, The hot-pressed welding portion of the plate (12) includes a first hot-pressed area (1201) on both sides and a second hot-pressed area (1202) on the other two sides. The width of the first hot-pressed area (1201) is greater than the hot-pressed width of the second hot-pressed area (1202). The hot-pressed width of the first hot-pressed area (1201) is not less than the length of the connecting portion (3). The protrusion (13) is formed by punching the first hot-pressed area (1201).

7. The manufacturing process of the conductive connection structure according to claim 5, characterized in that, The corner of the hot-pressed welded part of the plate (12) is provided with positioning holes (14).

8. The manufacturing process of the conductive connection structure according to claim 5, characterized in that, In the electroplating process, the metal plating layer is a nickel plating layer with a thickness of 3 μm, and the width of the second hot-pressing zone (1202) is 4.5-5.5 mm.

9. The manufacturing process of the conductive connection structure according to claim 5, characterized in that, The pressure for hot-press welding is 0.8-1.5 MPa, and the pressure is applied twice during hot-press welding.

10. The manufacturing process of the conductive connection structure according to claim 9, characterized in that, The first pressurization is at 30% pressure, and the pressurization time is: the thickness of the sheet material (11) 10-15s, the second pressurization is at 100% pressure, holding time: thickness of the sheet material (11) 20-30s.

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