Insulated wrapped copper bus

Abstract

This invention relates to the field of power conductive components technology, and discloses an insulating copper busbar, comprising: a copper busbar substrate, a composite insulation structure covering its outer surface, and an insulating reinforcement layer covering the outer surface of the composite insulation structure in stress concentration areas of the copper busbar substrate. The composite insulation structure includes, from the inside out, a bonding covering layer, a reinforcing insulating middle layer, and a wear-resistant protective outer layer, all sequentially bonded together. The insulating reinforcement layer and the composite insulation structure are integrally heat-pressed and cured. This invention employs a layered design of the composite insulation structure, balancing bonding and sealing, insulation withstand voltage, and wear resistance, completely solving the problems of traditional single-layer insulation structures' limited protection and weak performance. The insulation withstand voltage rating is significantly improved, and the flame-retardant and aging-resistant properties are excellent, making it suitable for harsh operating conditions in various scenarios such as high and low voltage and energy storage. Insulating reinforcement structures are set at the bends and corners of the copper busbar, comprehensively eliminating electrical safety hazards and significantly improving the safety and stability of the product.

Description

Technical Field

[0001] This invention relates to the field of electrical conductive accessories technology, and in particular to an insulating copper busbar. Background Technology

[0002] Copper busbars, also known as copper busbars or copper busbars, are core conductive connectors in high and low voltage switchgear, energy storage battery systems, electrical control cabinets, and rail transit electrical equipment. They are characterized by good conductivity, high current carrying capacity, and high mechanical strength. To prevent short circuits, leakage, and electric shocks during use, and to prevent oxidation and corrosion, the surface of the copper busbars must be insulated and protected.

[0003] Most copper busbars currently on the market use a single insulating tape wrapping or a single-layer sheath. However, these types of copper busbars are prone to insulation layer cracking and aging failure after long-term energized operation, leading to electrical safety hazards. Especially in stress concentration areas such as the corners and bends of the copper busbar, they are easily broken down and worn, making them high-risk locations for leakage and short circuit accidents. Therefore, they cannot meet the requirements of high-precision and high-safety-level electrical equipment. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an insulating wrapped copper busbar that can improve the insulation protection performance and operational stability of the copper busbar.

[0005] This invention provides an insulating copper busbar, comprising: a copper busbar substrate, a composite insulation structure covering its outer surface, and an insulating reinforcement layer covering the outer surface of the composite insulation structure in stress concentration areas of the copper busbar substrate; wherein, The composite insulation structure includes a bonding and covering layer, a reinforced insulation middle layer, and a wear-resistant protective outer layer, which are sequentially bonded and laid from the inside out. The insulating reinforcement layer and the composite insulation structure are integrally thermo-pressed and cured.

[0006] Optionally, the bonding and covering layer is a polyimide insulating film layer, which is bonded to the outer surface of the copper busbar substrate by low-temperature hot pressing.

[0007] Optionally, the thickness of the bonding and covering layer is 0.1mm to 0.3mm.

[0008] Optionally, the reinforced insulation middle layer is a flame-retardant polyester insulation tape, which is spirally wound around the outer layer of the bonding and covering layer.

[0009] Optionally, the overlap width of the reinforced insulation middle layer is 3mm to 5mm, the winding angle is 30° to 45°, and the thickness of the flame-retardant polyester insulation tape is 0.4mm to 0.8mm.

[0010] Optionally, the wear-resistant protective outer layer is a modified PVC insulating sheath, and both ends of the wear-resistant protective outer layer are sealed to the wiring terminals of the copper busbar substrate.

[0011] Optionally, the thickness of the wear-resistant protective outer layer is 0.2mm to 0.4mm, and the outer surface of the wear-resistant protective outer layer is provided with an anti-slip and wear-resistant textured structure.

[0012] Optionally, the insulating reinforcement layer covers all the edges and curved surfaces of the copper busbar substrate, and the thickness of the insulating reinforcement layer is 1.5 to 2 times the thickness of the composite insulation structure.

[0013] Optionally, the composite insulation structure is formed by segmented gradient hot pressing, with the hot pressing temperature of the bonding and covering layer being 80℃, the hot pressing temperature of the reinforcing insulation middle layer being 120℃, and the hot pressing temperature of the wear-resistant protective outer layer being 100℃.

[0014] Optionally, the copper busbar substrate is a tin-plated copper busbar with a surface roughness ≤1.6μm.

[0015] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art: This invention provides an insulated copper busbar with a composite insulation structure, comprising a bonding layer, a reinforced insulating middle layer, and a wear-resistant protective outer layer, all covering the outer surface of the copper busbar substrate. This layered design balances sealing, insulation withstand voltage, and wear resistance, completely solving the problems of limited protection and weak performance in traditional single-layer insulation structures. The insulation withstand voltage rating is significantly improved, and the flame-retardant and aging-resistant properties are excellent, making it suitable for harsh operating conditions in high and low voltage, energy storage, and other scenarios. Insulation reinforcement structures are added at the bends and corners of the copper busbar, specifically addressing the pain points of easy breakdown and wear at the corner insulation of traditional copper busbars. This comprehensively eliminates electrical safety hazards, significantly improving product safety and stability. Simultaneously, the integrated hot-pressing curing process ensures a tight, integrated structure without air bubbles, gaps, delamination, or wrinkles, resulting in high product consistency. It is not prone to detachment or cracking during long-term use, significantly extending its service life. Suitable for high and low voltage distribution cabinets, energy storage battery packs, and other applications, it offers structural stability, long service life, and convenient mass production. The overall structure is waterproof, dustproof, wear-resistant, and scratch-resistant, making it suitable for complex working environments. The structural design is adapted to automated mass production, resulting in good product consistency, high yield, and broad market application prospects. Attached Figure Description

[0016] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of the structure of an insulating copper busbar provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the composite insulation structure provided in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Copper busbar substrate; 2. Composite insulation structure; 21. Lamination and covering layer; 22. Reinforced insulation middle layer; 23. Wear-resistant protective outer layer; 3. Insulation reinforcement layer. Detailed Implementation

[0019] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0020] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] First, this embodiment of the invention provides an insulating wrapped copper busbar, specifically as follows: Figure 1 and Figure 2As shown, the structure includes: a copper busbar substrate 1, a composite insulation structure 2 covering its outer surface, and an insulation reinforcement layer 3 covering the stress concentration area of ​​the composite insulation structure 2. The copper busbar substrate 1, as the conductive core, is extruded from high-conductivity copper or low-alloy copper, and its cross-sectional shape can be designed as rectangular, trapezoidal, or irregular depending on the application. The composite insulation structure 2 is entirely covered on the outer surface of the copper busbar substrate 1, providing basic electrical insulation, mechanical protection, and environmental resistance. This composite insulation structure 2 is a multi-layered composite design. Specifically, the composite insulation structure 2 includes, from the inside out, a bonding and covering layer 21, a reinforcing insulation middle layer 22, and a wear-resistant protective outer layer 23, sequentially bonded together. The bonding and covering layer 21 uses a high-dielectric-strength, low-dielectric-loss insulating material (such as polyimide film or epoxy glass fiber prepreg). Its main function is to eliminate local electric field distortion caused by microscopic burrs on the copper busbar surface and to serve as a bottom-layer insulation barrier. The reinforced insulation middle layer 22 covers the outside of the bonding and covering layer 21. It adopts an alternating wrapping structure of mica tape and polyester film composite tape with matched thickness and dielectric constant, or a high-toughness modified polyphenylene ether (PPO) insulation layer, to withstand the rated voltage and operating overvoltage of the main circuit and provide the core insulation withstand voltage rating. The wear-resistant protective outer layer 23 is set on the outside of the reinforced insulation middle layer 22. It adopts a high wear-resistant and arc-resistant polyamide (PA) or thermoplastic polyester elastomer (TPEE) material, or a glass fiber reinforced epoxy resin layer, to resist friction, scratches and external mechanical impacts generated between the copper busbar and adjacent components during installation and use, while also having moisture-proof and dirt-proof properties. The insulation reinforcement layer 3 is integrally heat-pressed and cured with the composite insulation structure 2. The insulation reinforcement layer 3 is not laid all the way, but selectively covers the stress concentration area of ​​the copper busbar substrate 1 and is located on the outer surface of the composite insulation structure 2 at the corresponding position in the area. Stress concentration areas include, but are not limited to, the bends and corners of the copper busbar substrate, the ends of punched connections, the transition areas of crimped joints, and locations of abrupt changes in cross-section. The insulating reinforcement layer 3 uses the same material as the wear-resistant protective outer layer 23 or an insulating material with higher mechanical strength (such as extra-thickened glass fiber reinforced epoxy resin or aramid fiber composite material). Its local thickness is 1.2 to 2.0 times the thickness of the main body of the composite insulation structure 2, used to disperse and absorb concentrated mechanical strain caused by thermal expansion and contraction or electrodynamic stress of the copper busbar, effectively preventing insulation cracking. Crucially, the insulating reinforcement layer 3 and the composite insulation structure 2 are not bonded in stages or assembled in two stages, but rather manufactured using an integrated hot-pressing curing process. During the hot-pressing process, the interface material of the insulating reinforcement layer 3 and the material of the wear-resistant protective outer layer 23 undergo molten cross-linking or molecular chain diffusion under high temperature and pressure, forming a seamless fusion bonding area.This integrated molding structure not only eliminates the potential risks of interface bubbles and peeling that may exist in traditional layered bonding, but also significantly improves the bonding strength between the reinforced area and the main insulation layer. This ensures that the insulation reinforcement layer 3 does not undergo relative displacement or delamination under long-term vibration and temperature cycling conditions, thereby improving the long-term operational reliability and service life of the copper busbar under the combined effects of complex electrical and mechanical stresses.

[0022] To address the technical shortcomings of existing insulated copper busbars, which are prone to aging and cracking during long-term operation, especially in stress concentration areas such as corners and bends where breakdown and wear are likely to occur, making it difficult to meet the requirements of high-safety-level equipment, this invention provides the aforementioned insulated copper busbar. This copper busbar employs a multi-layer composite insulation structure consisting of a bonded outer layer, a reinforced insulating middle layer, and a wear-resistant protective outer layer. This creates a gradient and synergistic protection in terms of basic insulation, electrical strength, and external wear and impact resistance, effectively preventing the overall failure of a single insulation layer due to localized damage. Simultaneously, targeted insulation reinforcement layers are added to the stress concentration areas of the copper busbar and fused to the composite insulation structure using an integrated hot-pressing curing process. This structurally disperses and buffers the concentrated strain caused by thermal expansion and contraction and electromechanical stress, while the interface-free fusion eliminates the peeling and bubble risks inherent in traditional layered bonding. This significantly improves the long-term reliability of the copper busbar under complex electrical and mechanical coupling stresses, greatly reducing the risk of breakdown and short circuits, enabling it to meet the stringent requirements of high-precision, high-safety-level electrical equipment for the durability and stability of the insulation system.

[0023] Specifically, in this embodiment of the invention, the bonding and covering layer 21 is a polyimide insulating film layer, which is bonded to the outer surface of the copper busbar substrate 1 using a low-temperature hot-pressing method. The polyimide film possesses excellent dielectric strength (breakdown voltage up to 150kV / mm or higher), excellent high-temperature resistance (long-term operating temperature up to 200℃ or higher), and good dimensional stability. Its coefficient of thermal expansion is well-matched with copper, enabling it to expand and contract synchronously with the copper busbar substrate during drastic temperature changes. This effectively reduces the risk of interface separation caused by thermal stress, effectively eliminates the problem of localized suspension and leakage of the insulation layer, and ensures the sealing performance of the inner layer and the basic insulation performance.

[0024] In a preferred embodiment of the present invention, the thickness of the bonding coating layer 21 is controlled between 0.1 mm and 0.3 mm. This thickness range is not arbitrarily selected, but is optimized and determined after comprehensively considering multiple factors such as electrical performance, mechanical performance, bonding process adaptability, and overall structural coordination. Specifically, as follows: First, in terms of electrical insulation performance, the dielectric strength of polyimide film can typically reach 150 kV / mm to 300 kV / mm. Even at the minimum thickness of 0.1 mm, its breakdown voltage can still reach above 15 kV, meeting the withstand voltage requirements of most medium and low voltage electrical equipment for the bottom insulation. Setting the upper limit of the thickness to 0.3 mm ensures insulation margin while avoiding the problems of significantly increased material costs and uneven heat conduction during hot pressing due to excessive film thickness. Within this thickness range, the bonding coating layer 21 can effectively reduce the electric field strength on the copper busbar surface, suppress local corona discharge, and provide a reliable electric barrier for the upper reinforced insulation middle layer 22. Secondly, regarding the compatibility with the hot-pressing process, a thickness range of 0.1mm to 0.3mm ensures that the polyimide film has good thermal conductivity and consistent thermal response during low-temperature hot pressing. If the thickness is too thin (less than 0.1mm), the film is prone to wrinkles, cracks, or pinholes during hot pressing due to localized overheating or uneven pressure. Furthermore, its mechanical strength is insufficient to withstand the stretching and friction during the subsequent winding or wrapping of the reinforcing insulating middle layer 22. If the thickness is too thick (greater than 0.3mm), the film's thermal resistance increases, making it difficult to achieve uniform softening and sufficient flow under low-temperature hot pressing conditions. This may result in residual micro-bubbles at the bonding interface or insufficient bonding, thus reducing the interface bonding strength and insulation reliability. Thirdly, regarding the compatibility with the microstructure of the copper busbar substrate, after extrusion, drawing, or bending in actual production, the copper busbar substrate 1 inevitably has processing textures, micro-scratches, or unevenness with a depth of several micrometers to tens of micrometers on its surface. A film thickness of 0.1mm to 0.3mm provides sufficient material margin after hot pressing and softening to fill and cover these microscopic defects, forming a complete physical isolation layer. Simultaneously, the film at this thickness exhibits moderate flexibility, allowing it to naturally conform to the contours of the copper busbar surface. It maintains continuous and complete coverage, especially in the arc transition areas or non-planar parts of the copper busbar, preventing cracking or warping due to bending stress concentration. Fourth, regarding overall structural synergy, the 0.1mm to 0.3mm thickness of the bonding and covering layer 21 forms a reasonable gradation relationship with the subsequent thicknesses of the reinforcing insulating middle layer 22 and the wear-resistant protective outer layer 23. At this thickness, the bonding and covering layer 21 provides sufficient underlying insulation protection without excessively increasing the outer diameter of the entire composite insulation structure 2, which is beneficial for the installation and wiring of the copper busbar within space-constrained electrical cabinets. Furthermore, the polyimide film at this thickness has a low heat capacity, allowing it to respond quickly to temperature changes when the copper busbar experiences short-term overload heating, maintaining synchronous thermal expansion and contraction with the copper busbar substrate, further reducing the risk of interfacial thermal stress accumulation.Fifth, regarding economic efficiency and engineering practicality, polyimide film, as a high-performance engineering material, has a relatively high cost per unit area. Controlling the thickness of the lamination layer 21 within a reasonable range of 0.1mm to 0.3mm achieves an optimal balance between performance redundancy and economic cost, ensuring insulation reliability and process feasibility while avoiding material waste caused by over-design, thus possessing significant value for industrial application. Therefore, this invention limits the thickness of the lamination layer 21 to 0.1mm to 0.3mm, which is the optimal matching range under multiple constraints such as electrical strength, process yield, interface bonding quality, structural synergy, and economic efficiency. The polyimide film layer within this thickness range can form a dense, continuous, and defect-free underlying insulation barrier after low-temperature hot pressing, providing a solid guarantee for the long-term stable operation of the composite insulation structure 2 as a whole.

[0025] Optionally, the reinforced insulation middle layer 22 is a flame-retardant polyester insulation tape, which is spirally wound around the outer layer of the bonding and covering layer 21, and the flame retardant rating meets the UL94 V0 standard.

[0026] This invention achieves a systematic improvement in insulation performance and service reliability by optimizing the layered structure and process parameters: The bonding and covering layer 21 uses a polyimide film with a thickness of 0.1mm to 0.3mm, and is tightly bonded to the surface of the copper busbar substrate 1 by low-temperature hot pressing (120℃ to 160℃, 0.5MPa to 2.0MPa). This thin-layer design ensures a breakdown margin of over 15kV while taking into account thermal response consistency and economy. The low-temperature process effectively prevents the copper busbar substrate from softening due to thermal annealing, and the softened film fully fills the surface micro-defects, eliminating the risk of air gap discharge. On this basis, the reinforcing insulation middle layer 22 is made of flame-retardant polyester insulation tape spirally wound at an overlap rate of 50% to 75% and an angle of 15° to 45°, forming a redundant stacked structure of 2 to 4 layers, which significantly improves the main insulation withstand voltage level (above 20kV / mm for a single layer) and UL94. The V-0 flame-retardant safety margin, coupled with the adaptive compensation of interlayer slippage at the spiral interface for linear strain caused by thermal expansion and contraction of the copper busbar, prevents insulation layer cracking. In the synergistic effect of the two layers, the uniform radial clamping force generated by the spiral winding consolidates the thermal bonding effect of the bottom layer, while the high dielectric level rectification substrate provided by the polyimide bottom layer creates an optimized electric field distribution environment for the upper layer of wound insulation tape. The two form a gradient insulation protection system from three dimensions: material matching, process connection, and structural complementarity, which significantly improves the electrical safety margin and mechanical structural stability of the copper busbar under overload, short circuit, and long-term thermal cycling conditions.

[0027] Optionally, the overlap width of the reinforced insulation middle layer 22 is 3mm to 5mm, the winding angle is 30° to 45°, and the thickness of the flame-retardant polyester insulation tape is 0.4mm to 0.8mm. Through a standardized spiral winding method with fixed angles and fixed overlap, uniform coverage of the middle layer without dead corners can be ensured, significantly improving the overall insulation withstand voltage performance and flame-retardant protection capability of the copper busbar, fully meeting the safety operation standards for high and low voltage electrical equipment.

[0028] Optionally, the wear-resistant protective outer layer 23 is a modified PVC insulating sheath, and both ends of the wear-resistant protective outer layer 23 are sealed to the wiring terminals of the copper busbar substrate 1. This invention uses a modified PVC insulating sheath as the wear-resistant protective outer layer 23. This material, through plasticization, stabilization, and wear-resistant modification, achieves a volume resistivity ≥10¹³Ω·cm, dielectric strength ≥18kV / mm, and a flame retardant rating of UL94. The overall performance is improved by V-0 rating and a 30%~50% reduction in wear. It is tightly covered on the outside of the reinforced insulation middle layer 22 by extrusion or encapsulation. The radial compression force formed by the cooling and shrinkage of molten PVC consolidates the dense bond of the internal layers. At the same time, the two ends of the sheath are integrated with the root of the copper busbar terminal by hot melting or injection molding. This sealing structure not only effectively blocks the channels for moisture, dust and corrosive gases to penetrate into the insulation layers along the axis, inhibiting insulation degradation due to moisture and surface creep, but also prevents the sheath from vibrating and shifting through end fixation. The entire composite insulation structure forms a gradient modulus matching system of "soft bottom layer - rigid reinforcement layer - tough sealing protection layer". While significantly improving the wear resistance and impact resistance of the outer layer, it constructs a fully enclosed insulation system, isolating it from external oxygen and moisture corrosion. This comprehensively enhances the long-term service reliability and environmental adaptability of the copper busbar under harsh conditions such as humidity, salt spray, dirt and vibration.

[0029] Optionally, the thickness of the wear-resistant protective outer layer 23 is 0.2mm to 0.4mm, and the outer surface of the wear-resistant protective outer layer 23 is provided with an anti-slip and wear-resistant textured structure. Controlling its thickness within the range of 0.2mm to 0.4mm achieves an optimized balance between mechanical strength and flexibility. A thickness of not less than 0.2mm ensures that the sheath has sufficient mechanical redundancy to resist scratches during installation, long-term vibration and friction, and external impacts without damage. A thickness of not more than 0.4mm avoids excessively increasing the overall outer diameter of the copper busbar, which would affect the spacing within the narrow cabinet. Simultaneously, it ensures that the sheath has good flexibility to facilitate smooth coverage of the copper busbar bending areas and uniform heat-sealing. The outer surface of the wear-resistant protective outer layer 23 is provided with an anti-slip and wear-resistant textured structure. This texture can be made into a mesh, stripe, or granular raised pattern by embossing, knurling, or molding. On the one hand, by increasing the surface roughness, it significantly improves the wear resistance of the sheath, so that wear first acts on the top of the textured protrusions rather than the base surface of the sheath body, thereby delaying the overall thinning and failure process of the sheath. On the other hand, it enhances the grip friction during the installation and maintenance of the copper busbar, avoiding slippage and bump damage during operation. At the same time, the concave and convex texture also increases the heat dissipation area of ​​the outer surface of the sheath, which is conducive to the radiation and convection dissipation of Joule heat during the operation of the copper busbar, combining multiple engineering effects of anti-slip, wear resistance, and auxiliary heat dissipation. The outer layer structure can effectively resist external scratches and wear during assembly and maintenance, while isolating external moisture and dust from entering the insulation layer, avoiding insulation failure caused by moisture and dust accumulation in the insulation structure, and greatly improving the product's environmental adaptability and service life.

[0030] This invention addresses high-risk areas such as the sharp corners and curved surfaces of the copper busbar substrate 1, where electric field distortion is severe and mechanical stress is highly concentrated. The insulating reinforcement layer 3 is designed to completely cover all these geometrically abrupt changes. Specifically, the edges, right-angle turns, and outer and inner curved surfaces of the curved sections of the copper busbar are all completely covered by this reinforcement layer, leaving no blind spots. Simultaneously, the thickness of the insulating reinforcement layer 3 is set to 1.5 to 2 times the thickness of the main body of the composite insulation structure 2 (if the total thickness of the composite insulation structure is 0.8 mm, then the thickness of the reinforcement layer is 1.2 mm to 1 mm). The 6mm thickness range was determined based on several considerations: Firstly, sufficient thickness increment creates an effective "insulation thickening shielding effect" at the sharp corners, mitigating the electric field concentration at these points through geometric encapsulation, significantly reducing the field strength and thus suppressing corona discharge and local breakdown. Secondly, the thickened reinforcing layer provides ample material redundancy at bending points. When the copper busbar bends due to thermal expansion and contraction or electrodynamic stress, the reinforcing layer can absorb and disperse concentrated strain through its elastic deformation, preventing strain... This prevents insulation cracking caused by focusing on a single cross-section; furthermore, the 1.5 to 2 times thickness ratio ensures sufficient reinforcement margin while avoiding shrinkage stress concentration or molding defects caused by the difference in curing rates between the inner and outer layers during hot pressing of an excessively thick reinforcement layer. It also considers the installation compatibility of the copper busbar within a limited space. After the reinforcement layer is integrally hot-pressed and cured with the composite insulation structure 2, a seamless and interface-free fused thickened structure is formed in the corners and bending areas, eliminating the bubbles, wrinkles, or adhesive interfaces that may occur with traditional separate reinforcement sheets. The process defects such as stripping are eliminated, while ensuring that the bonding strength and electrical continuity between the reinforced part and the main insulation layer are completely consistent. Thus, a reinforced protective barrier with three functions—electric field mitigation, mechanical enhancement, and thermal strain buffering—is built at the weakest point of the copper busbar's geometric change. This fundamentally solves the technical problem of the insulation layer being prone to premature failure at sharp corners and bends in existing technologies. It also addresses the industry pain points of traditional copper busbars having excessively thin insulation layers at sharp corners and bends, which are prone to wear and breakdown. This comprehensively strengthens the protective capabilities of weak insulation locations and completely eliminates the safety hazards of corner leakage and short circuits.

[0031] Optionally, the composite insulation structure 2 is integrally formed using segmented gradient hot-pressing curing. The hot-pressing temperature of the bonding and covering layer 21 is 80℃, the hot-pressing temperature of the reinforcing insulation middle layer 22 is 120℃, and the hot-pressing temperature of the wear-resistant protective outer layer 23 is 100℃. After hot-pressing, each layer is tightly bonded together, perfectly adapting to the surface contour of the copper busbar substrate, resulting in a gap-free and bubble-free bond. The segmented gradient hot-pressing curing temperatures are set from the inside out to 80℃, 120℃, and 100℃, precisely matching the optimal molding temperature of each insulating layer. This balances the bonding stability of the inner layer, the curing strength of the middle layer, and the protective integrity of the outer layer, ensuring the integrated molding effect and structural stability of the overall insulation structure.

[0032] Optionally, the copper busbar substrate is made of tin-plated copper with a surface roughness of ≤1.6μm. The copper busbar substrate material has excellent conductivity and stable current carrying capacity. After fine surface treatment, it is free of burrs and protrusions, which not only ensures the normal conductivity of the equipment, but also effectively improves the adhesion of the insulation layer, preventing the insulation layer from falling off or curling, and further improving the stability of the overall structure.

[0033] Example 1 An insulating copper busbar includes a tin-plated copper busbar substrate with a surface roughness of 1.2 μm. From the inside out, the copper busbar substrate 1 is sequentially configured with an adhesive covering layer 21, a reinforcing insulating middle layer 22, and a wear-resistant protective outer layer 23. The adhesive covering layer 21 is a 0.2 mm thick polyimide film, bonded by low-temperature hot pressing at 80°C. The reinforcing insulating middle layer 22 is a 0.6 mm thick flame-retardant polyester insulating tape, with a wrapping overlap width of 4 mm and a wrapping angle of 35°. The wear-resistant protective outer layer 23 is a 0.3 mm thick modified PVC sheath with sealed edges. Insulating reinforcement layers 3 are provided at the bends and corners of the copper busbar, with a thickness 1.8 times that of conventional areas. The entire assembly is cured by gradient hot pressing.

[0034] The copper busbar prepared in this embodiment has a tightly bonded insulation layer without bubbles, a withstand voltage of ≥10kV, a flame retardant rating of UL94V0, and wear resistance that is 60% higher than that of traditional products. It also shows no aging or delamination under long-term high-temperature conditions.

[0035] Example 2 An insulating copper busbar includes a tin-plated copper busbar substrate with a surface roughness of 1.6 μm; a bonding and covering layer 21 is a 0.1 mm thick polyimide film; a reinforcing insulating middle layer 22 is a 0.4 mm thick flame-retardant polyester insulating tape with a wrapping overlap width of 3 mm and a wrapping angle of 30°; and a wear-resistant protective outer layer 23 is a 0.2 mm thick modified PVC sheath. The insulation reinforcement layer 3 is 1.5 times thicker than that of the conventional area, making it suitable for use in small precision electrical equipment. It is compact in size and has excellent protective performance.

[0036] Example 3 An insulating copper busbar includes a tin-plated copper busbar base, a 0.3mm thick polyimide film as the bonding and covering layer 21, a 0.8mm thick flame-retardant polyester insulating tape as the reinforcing insulating middle layer 22, with a wrapping overlap width of 5mm and a wrapping angle of 45°; and a 0.4mm thick modified PVC sheath as the wear-resistant protective outer layer 23. The thickness of the insulating reinforcing layer 3 is twice that of the conventional area, making it suitable for high-voltage and high-power electrical equipment, and significantly improving the insulation withstand voltage, impact resistance, and wear resistance.

[0037] The above inventions are merely a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. An insulating copper busbar, characterized in that, include: The copper busbar substrate, the composite insulation structure covering its outer surface, and the insulation reinforcement layer covering the outer surface of the composite insulation structure in the stress concentration area of ​​the copper busbar substrate; wherein, The composite insulation structure includes, from the inside out, a bonding and covering layer, a reinforced insulating middle layer, and a wear-resistant protective outer layer, which are sequentially bonded and laid out. The insulating reinforcement layer is integrally heat-pressed and cured with the composite insulation structure.

2. The insulating copper busbar as described in claim 1, characterized in that, The bonding and covering layer is a polyimide insulating film layer, which is bonded to the outer surface of the copper busbar substrate by low-temperature hot pressing.

3. The insulating copper busbar as described in claim 1, characterized in that, The thickness of the bonding and covering layer is 0.1 mm to 0.3 mm.

4. The insulating copper busbar as described in any one of claims 1 to 3, characterized in that, The reinforced insulating middle layer is a flame-retardant polyester insulating tape, which is spirally wound around the outer layer of the bonding and covering layer.

5. The insulating copper busbar as described in claim 4, characterized in that, The width of the overlapping layer of the reinforced insulation middle layer is 3mm to 5mm, the winding angle is 30° to 45°, and the thickness of the flame-retardant polyester insulation tape is 0.4mm to 0.8mm.

6. The insulating copper busbar as described in claim 1, characterized in that, The wear-resistant protective outer layer is a modified PVC insulating sheath, and both ends of the wear-resistant protective outer layer are sealed to the wiring terminals of the copper busbar substrate.

7. The insulating copper busbar as described in claim 6, characterized in that, The wear-resistant protective outer layer has a thickness of 0.2mm to 0.4mm, and the outer surface of the wear-resistant protective outer layer is provided with an anti-slip and wear-resistant textured structure.

8. The insulating copper busbar as described in claim 1, characterized in that, The insulating reinforcement layer covers all the edges and curved surfaces of the copper busbar substrate, and the thickness of the insulating reinforcement layer is 1.5 to 2 times the thickness of the composite insulation structure.

9. The insulating copper busbar as described in claim 1, characterized in that, The composite insulation structure is integrally formed by segmented gradient hot pressing and curing. The hot pressing temperature of the bonding and covering layer is 80℃, the hot pressing temperature of the reinforcing insulation middle layer is 120℃, and the hot pressing temperature of the wear-resistant protective outer layer is 100℃.

10. The insulating copper busbar as described in claim 1, characterized in that, The copper busbar substrate is a tin-plated copper busbar with a surface roughness of ≤1.6μm.

Images