Laminated metal foil winding structure and process thereof

Abstract

The application discloses a laminated metal foil winding structure and a process thereof, and relates to the technical field of electromagnetic winding processing and manufacturing, which comprises a winding composite unit, wherein the winding composite unit comprises a first coil layer, a first insulating layer, a heat dissipation layer, a second insulating layer and a second coil layer. The application adopts a pure mechanical pressing composite structure of an aluminum foil as a main metal foil, an insulating film and a heat dissipation back plate, discards traditional processes of PCB etching and enameled wire winding, can break through the industry bottleneck of high temperature rise and difficult mass production of aluminum winding, realizes the substitution of copper winding with aluminum at low cost, greatly reduces the raw material and processing cost, and guarantees the flatness of the plate surface, the symmetry of the magnetic field and the stable torque output through the built-in welding of the inner diameter, the avoidance of the window and the staggered layout design of the same layer welding points.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic winding processing and manufacturing technology, specifically a laminated metal foil winding structure and its process. Background Technology

[0002] Laminated metal foil winding structures are a type of winding where thin conductive metal foils of copper and aluminum are used as conductive layers, and insulating film / paper is used as the interlayer isolation medium. The two are alternately wound and stacked layer by layer along the radial direction of the iron core, and then mechanically compacted, impregnated with resin, and hot-pressed to form a dense, integrated, rigid composite winding. However, existing electromagnetic winding forming processes have obvious industry shortcomings and technical barriers to copper-to-aluminum conversion. Traditional enameled copper windings have high raw material costs and strong resource dependence. Although the industry trend of copper-to-aluminum replacement is clear, aluminum has a significantly higher resistivity than copper. Traditional winding processes lack dedicated heat dissipation structures, resulting in aluminum windings with excessive temperature rise, poor overload capacity, and unstable performance. At the same time, traditional enameled wire winding processes have low automation, poor consistency of multi-layer winding stacking, and uneven heat dissipation. Ultra-thin flat aluminum windings cannot be mass-produced. PCB copper foil etched windings rely on special copper-clad PCB substrates, which are expensive in raw materials, have complex etching and electroplating processes, long production cycles, and limited yield rates. Moreover, the industry has not yet formed a mature and stable complete set of mass production processes for aluminum foil PCBs, making it difficult to standardize and apply aluminum foil windings on a large scale.

[0003] Traditional winding interlayer conduction often employs substrate vias and external lead soldering, which suffers from poor conduction stability, messy joints, high insulation risk, and inability to mass-produce on large boards. Furthermore, the overlapping and concentrated placement of solder joints at the beginning and end of conventional winding layers easily leads to localized thickness stacking, solder joint interference, and uneven board surfaces, severely impacting multi-layer stacking accuracy and insulation safety. This makes it impossible to simultaneously meet the differentiated demands of high precision and low jitter in distributed winding and high torque and high density in concentrated winding, further hindering the industrialization of aluminum foil windings in servo motors and low-altitude flight motors. Currently, the industry lacks a composite winding solution with a regular structure, reasonable solder joint layout, excellent heat dissipation, low cost, large-scale mass production capability, specific compatibility with aluminum foil materials, and compatibility with multiple conductive metals. This solution cannot meet the industry's demand for low-cost, high-consistency, and mass-producible copper-to-aluminum replacement production. Therefore, this paper presents a laminated metal foil winding structure and its process, which can eliminate the shortcomings of existing devices. Summary of the Invention

[0004] The purpose of this invention is to provide a laminated metal foil winding structure and its process to solve the problems in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A laminated metal foil winding structure includes a winding composite unit, wherein the winding composite unit includes a first coil layer, a first insulating layer, a heat dissipation layer, a second insulating layer, and a second coil layer; The first coil layer, the first insulating layer, the heat dissipation layer, the second insulating layer, and the second coil layer are stacked. Both the first and second insulating layers have welding openings, and the heat dissipation layer has a clearance opening at the position corresponding to the orthographic projection of the welding opening. The aperture of the clearance opening is larger than that of the welding opening.

[0006] Based on the above technical solutions, the present invention also provides the following optional technical solutions: In one alternative: the head and tail welding points of the first coil layer and the second coil layer are arranged in a staggered manner. The head and tail welding points on the first coil layer and the second coil layer are offset forward and backward along the circumference, and the head and tail welding points on the first coil layer and the second coil layer do not overlap with each other.

[0007] In one alternative: the heat dissipation layer adopts a single metal plate structure or a multi-metal plate stacked structure, and the first coil layer, the second coil layer, and the heat dissipation layer are all made of metal foil.

[0008] In one alternative: the first coil layer and the second coil layer are distributed winding layout structures or concentrated winding area layout structures. The coils of the first coil layer and the second coil layer are provided with multiple sectors or individual sectors at equal intervals along the circumference. Each sector is provided with a single turn or multiple turns of circuit.

[0009] In one alternative: the winding composite unit is compatible with both the independent heat dissipation backplate full-area heat dissipation mode and the self-heat dissipation mode without an independent heat dissipation layer; The self-heating mode has no independent heat dissipation layer, the wiring areas on the first coil layer and the second coil layer do not overlap, and the wiring areas on the first coil layer and the second coil layer are fully covered and staggered.

[0010] In one alternative: multiple winding composite units are arranged in a matrix array on an ultra-large solid substrate.

[0011] In one alternative configuration, the thicknesses of the first coil layer, the first insulation layer, the heat dissipation layer, the second insulation layer, and the second coil layer can all be independently adjusted.

[0012] In one alternative: the coils of the first coil layer and the second coil layer are provided with weak connection roots, and the weak connection roots are breakable and separable structures.

[0013] This invention also discloses a fabrication process for a laminated metal foil winding structure, comprising the following steps: Step 1: Raw material pretreatment: The metal foil, insulating film, and heat dissipation metal plate are flattened and cut into extra-large whole-board substrates, which are used to prepare the first coil layer, the second coil layer, the first insulating layer, the second insulating layer, and the heat dissipation layer, respectively. The oxide layer, impurities, and burrs on the surface of each substrate are removed. Step 2: Window Forming: According to the preset interlayer series node positions and the layout rules of staggered weld points in the same layer, welding windows are opened on the entire plate of the first insulation layer and the second insulation layer. At the same time, avoidance windows are opened at the corresponding positions of the heat dissipation layer, and the aperture of the avoidance windows is larger than the aperture of the welding windows. Step 3: Single-layer integrated composite molding: The first coil layer, the first insulation layer, the heat dissipation layer, the second insulation layer, and the second coil layer are precisely aligned and stacked, and then pressed together by mechanical tooling. The single-layer winding composite unit whole board substrate is prepared by high-temperature hot pressing curing or room-temperature anaerobic adhesive cold pressing curing process. Step 4: Weak connection root punching: Weak connection root punching is performed to disconnect the weak connection roots between each coil to avoid difficulties in cutting the entire board. Step 5: Multi-layer stacked fixed-point welding: According to the preset winding turns and thickness requirements, stack the entire substrate of the multi-layer winding composite unit, and use the board-side pressing welding at the insulation window position to make the second coil layer of one winding composite unit connected in series with the first coil layer of another winding composite unit. Step Six: Integrated Forming of the Whole Board: After completing multi-layer stacking and welding, a complete ultra-large winding whole board substrate is formed. All welding nodes are uniformly located in the inner area of ​​the substrate, and the welding points in the same layer are staggered. The overall board surface is flat and uniform. Step 7: Matrix-style batch cutting: Perform matrix-style batch cutting according to the target winding specifications to obtain multiple standardized metal foil composite winding blanks in one batch; Step 8: Insulation Testing and Finishing: Insulation performance, conductivity, and surface flatness of the cut individual winding blanks are tested to complete the finished product preparation.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention adopts a pure mechanical pressing composite structure of aluminum foil as the main metal foil, insulating film, and heat dissipation backplate, which abandons the traditional processes of PCB etching and enameled wire winding. It can overcome the industry bottleneck of high temperature of aluminum winding and difficulty in mass production, and realize the replacement of copper with aluminum in motor winding at low cost, which greatly reduces raw material and processing costs.

[0015] 2. This invention, through its internal diameter welding, heat dissipation backplate with recessed windows, and staggered layout of weld points in the same layer, can take into account high precision, low vibration, high torque, and high density working conditions, eliminate the risk of leakage and short circuit, ensure flatness of the board surface, symmetrical magnetic field, and more stable torque output.

[0016] 3. This invention uses an independent heat dissipation backplate for full-area heat dissipation and a dual-mode switching scheme of staggered self-heat dissipation between upper and lower layers to specifically compensate for the defect of high resistivity of aluminum foil. It is suitable for both high-power and low-line-width high-density windings, providing uniform heat dissipation, effectively reducing temperature rise, and improving overload capacity.

[0017] 4. This invention utilizes a large-plate matrix array and a small-root weak connection batch manufacturing process, combined with an integrated molding positioning and mounting hole, to produce dozens to hundreds of windings at a time. This simplifies the splitting and cutting process, significantly improves mass production efficiency, and simultaneously enhances winding consistency and overall assembly precision.

[0018] 5. This invention features a universal structural design with adjustable thickness and number of turns, and adopts a pure physical processing flow without etching or electroplating. It is compatible with various conductive materials such as aluminum, copper, and superconductors, and can be adapted to all types of electromagnetic equipment, simplifying production management and stabilizing mass production yield. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the winding explosion structure of the present invention.

[0020] Figure 2 This is a schematic diagram of the preparation steps of the present invention.

[0021] Figure 3 This is a schematic diagram of the raw material pretreatment process structure of the present invention.

[0022] Figure 4 This is a schematic diagram of the window forming process of the present invention.

[0023] Figure 5 This is a schematic diagram of the single-layer integrated composite molding process structure of the present invention.

[0024] Figure 6 This is a schematic diagram of the multi-layer stacked fixed-point welding process structure of the present invention.

[0025] Figure 7 This is a schematic diagram of the integrated molding process of the present invention.

[0026] Figure 8 This is a schematic diagram of the matrix-style batch cutting process structure of the present invention.

[0027] Figure 9 This is a schematic diagram of the insulation testing and finalization process of the present invention.

[0028] Figure reference numerals: 1. Winding composite unit; 101. First coil layer; 102. First insulation layer; 103. Heat dissipation layer; 104. Second insulation layer; 105. Second coil layer. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] In one embodiment, such as Figure 1 As shown, a laminated metal foil winding structure includes a winding composite unit 1, which includes a first coil layer 101, a first insulating layer 102, a heat dissipation layer 103, a second insulating layer 104, and a second coil layer 105. The first coil layer 101, the first insulating layer 102, the heat dissipation layer 103, the second insulating layer 104, and the second coil layer 105 are stacked. The thickness of the first coil layer 101, the first insulating layer 102, the heat dissipation layer 103, the second insulating layer 104, and the second coil layer 105 can all be independently adjusted. Both the first insulating layer 102 and the second insulating layer 104 have welding openings. The heat dissipation layer 103 has a clearance opening at the position corresponding to the orthogonal projection of the welding opening. The diameter of the clearance opening is larger than that of the welding opening. The head and tail welding points of the first coil layer 101 and the second coil layer 105 are staggered. The head and tail welding points on the first coil layer 101 and the second coil layer 105 are offset circumferentially. The welding points and the tail welding points do not overlap with each other. The heat dissipation layer 103 adopts a single metal plate structure or a multi-metal plate stacked structure. The first coil layer 101, the second coil layer 105, and the heat dissipation layer 103 are all made of metal foil. The first coil layer 101 and the second coil layer 105 are distributed winding layout structures or concentrated winding area layout structures. The coils of the first coil layer 101 and the second coil layer 105 are provided with multiple sectors or individual sectors at equal intervals along the circumference. Single-turn or multi-turn lines are provided in the sector. In one embodiment, such as Figure 1 As shown, the winding composite unit 1 is compatible with both the independent heat dissipation backplate full-area heat dissipation mode and the self-heat dissipation mode without an independent heat dissipation layer. In the self-heating mode, there is no independent heat dissipation layer 103, and the wiring areas on the first coil layer 101 and the second coil layer 105 do not overlap. The wiring areas on the first coil layer 101 and the second coil layer 105 are fully covered and staggered. In one embodiment, such as Figure 1 As shown, multiple winding composite units 1 are arranged in a matrix array on a large whole board substrate. The coils of the first coil layer 101 and the second coil layer 105 are provided with weak connection roots, which are breakable and separable structures.

[0031] like Figures 1-9 As shown, a fabrication process for a laminated metal foil winding structure includes the following steps: Step 1: Raw material pretreatment: Metal foil (one or more of aluminum foil, copper foil or superconducting conductive metal foil can be used), high temperature resistant insulating film, and heat dissipation metal plate are flattened and cut into ultra-large whole board substrates, which are used to prepare the first coil layer 101, the second coil layer 105, the first insulating layer 102, the second insulating layer 104 and the heat dissipation layer 103, respectively. The oxide layer, impurities and burrs on the surface of each substrate are removed by mechanical or chemical means to ensure the flatness of each layer and the cleanliness of the surface. Step 2: Window Forming: According to the preset interlayer series node positions and the layout rules of staggered solder points in the same layer (the welding points at the beginning and end of the first coil layer 101 are offset forward and backward along the circumference and do not overlap, and the same applies to the second coil layer 105), welding windows are opened on the entire plate of the first insulating layer 102 and the second insulating layer 104. At the same time, avoidance windows are opened at the corresponding projection position of the welding windows on the heat dissipation layer 103, and the aperture of the avoidance windows is larger than the aperture of the welding windows, so that the interlayer welding area completely avoids the heat dissipation layer 103, ensuring that the welding conduction only occurs between the upper and lower coil layers, and preventing the heat dissipation layer 103 from participating in the conduction. Step 3: Single-layer integrated composite molding: The first coil layer 101, the first insulation layer 102, the heat dissipation layer 103, the second insulation layer 104, and the second coil layer 105 are precisely aligned and stacked, and then pressed together by mechanical tooling. The single-layer winding composite unit 1 is prepared by high-temperature hot pressing curing or room-temperature anaerobic adhesive cold pressing curing process. Multiple winding composite units 1 are arranged in a matrix array on the ultra-large whole board substrate. The coils of the first coil layer 101 and the second coil layer 105 are provided with weak connection roots. The whole board retains only a limited number of connection points, and the rest of the area is independent of each other. Step 4: Weak connection root punching: Weak connection root punching is performed to disconnect the weak connection roots between each coil to avoid difficulties in cutting the entire board. Step 5: Multi-layer stacking and fixed-point welding: According to the preset winding turns and thickness requirements, stack the entire substrate of multi-layer winding composite unit 1. At the insulation window position, use the board-side pressing welding process to make the second coil layer 105 of one winding composite unit 1 connected in series with the first coil layer 101 of another winding composite unit 1. Complete the end-to-end connection of the interlayer conductive metal foil circuit layer layer by layer. The whole board maintains the matrix array arrangement and weak connection state to ensure accurate multi-layer stacking alignment and flat board surface. Step Six: Integrated Forming of the Whole Board: After completing the multi-layer stacking and welding, a complete ultra-large winding whole board substrate is formed. All welding nodes are uniformly located in the inner area of ​​the substrate, and the welding points in the same layer are staggered. The welding points at the beginning and end of the first coil layer 101 and the second coil layer 105 are offset forward and backward along the circumference and do not overlap with each other, so as to avoid the stacking and protrusion of welding points and ensure that the board surface is flat and uniform. Step 7: Matrix-style batch cutting: Matrix-style batch cutting is performed according to the target winding specifications to obtain multiple standardized laminated metal foil composite winding blanks with regular shape and no connection residue in one batch, which greatly reduces the cutting difficulty and improves the mass production yield. Dozens to hundreds of standardized winding blanks can be formed in a single whole board cutting. Step 8: Insulation Testing and Finishing: The insulation performance, conductivity, and flatness of the cut individual winding blanks are tested to verify the reliability of interlayer insulation, the integrity of coil series conduction, and the overall forming quality, thus completing the finished product preparation.

[0032] The above-mentioned manufacturing process requires no PCB substrate, no etching, and no electroplating. It is formed by pure physical mechanical pressing and welding, which is suitable for the large-scale, low-cost mass production of aluminum foil windings. It is also compatible with the replacement of conductive metal materials such as copper foil and superconducting materials. At the same time, the process can flexibly accommodate both independent heat dissipation backplate full-area heat dissipation mode and self-heating mode without independent heat dissipation layer, adapting to different scenario requirements of conventional high-power and small line width high-density compact windings.

[0033] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A laminated metal foil winding structure, comprising a winding composite unit (1), characterized in that, The winding composite unit (1) includes a first coil layer (101), a first insulation layer (102), a heat dissipation layer (103), a second insulation layer (104), and a second coil layer (105). The first coil layer (101), the first insulating layer (102), the heat dissipation layer (103), the second insulating layer (104), and the second coil layer (105) are stacked. Both the first insulating layer (102) and the second insulating layer (104) have welding openings. The heat dissipation layer (103) has a clearance opening at the position corresponding to the orthographic projection of the welding opening. The aperture of the clearance opening is larger than that of the welding opening.

2. The laminated metal foil winding structure according to claim 1, characterized in that, The head and tail welding points of the first coil layer (101) and the second coil layer (105) are arranged in a staggered manner. The head and tail welding points on the first coil layer (101) and the second coil layer (105) are offset forward and backward along the circumference. The head and tail welding points on the first coil layer (101) and the second coil layer (105) do not overlap with each other.

3. The laminated metal foil winding structure according to claim 1, characterized in that, The heat dissipation layer (103) adopts a single metal plate structure or a multi-metal plate stacked structure. The first coil layer (101), the second coil layer (105), and the heat dissipation layer (103) are all made of metal foil.

4. The laminated metal foil winding structure according to claim 1, characterized in that, The first coil layer (101) and the second coil layer (105) are distributed winding layout structures or concentrated winding area layout structures. The coils of the first coil layer (101) and the second coil layer (105) are provided with multiple sectors or individual sectors at equal intervals along the circumference. Each sector is provided with a single turn or multiple turns of circuit.

5. The laminated metal foil winding structure according to claim 1, characterized in that, The winding composite unit (1) is compatible with both independent heat dissipation backplate full-area heat dissipation mode and self-heat dissipation mode without independent heat dissipation layer. The self-heating mode has no independent heat dissipation layer (103), the wiring areas on the first coil layer (101) and the second coil layer (105) do not overlap, and the wiring areas on the first coil layer (101) and the second coil layer (105) are fully covered and staggered.

6. The laminated metal foil winding structure according to claim 1, characterized in that, Multiple winding composite units (1) are arranged in a matrix array on a large whole plate substrate.

7. The laminated metal foil winding structure according to claim 1, characterized in that, The thicknesses of the first coil layer (101), the first insulation layer (102), the heat dissipation layer (103), the second insulation layer (104), and the second coil layer (105) can all be independently adjusted.

8. The laminated metal foil winding structure according to claim 1, characterized in that, The coils of the first coil layer (101) and the second coil layer (105) are provided with weak connection roots, which are breakable and separable structures.

9. A manufacturing process for a laminated metal foil winding structure according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Raw material pretreatment: The metal foil, insulating film and heat dissipation metal plate are flattened and cut into extra-large whole plate substrates, which are used to prepare the first coil layer (101), the second coil layer (105), the first insulating layer (102), the second insulating layer (104) and the heat dissipation layer (103), respectively, and the oxide layer, impurities and burrs on the surface of each substrate are removed; Step 2: Window Forming: According to the preset interlayer series node position and the layout rules of the same layer staggered welding points, welding windows are opened on the entire plate of the first insulating layer (102) and the second insulating layer (104), and at the same time, avoidance windows are opened at the corresponding position of the heat dissipation layer (103), and the aperture of the avoidance window is larger than the aperture of the welding window. Step 3: Single-layer integrated composite molding: The first coil layer (101), the first insulation layer (102), the heat dissipation layer (103), the second insulation layer (104), and the second coil layer (105) are precisely aligned and stacked, and then pressed together by mechanical tooling. The single-layer winding composite unit (1) whole board substrate is prepared by high temperature hot pressing curing or room temperature anaerobic adhesive cold pressing curing process. Step 4: Weak connection root punching: Weak connection root punching is performed to disconnect the weak connection roots between each coil to avoid difficulties in cutting the entire board. Step 5: Multi-layer stacked fixed-point welding: According to the preset winding turns and thickness requirements, stack the entire substrate of the multi-layer winding composite unit (1), and use the board-side pressing welding at the insulation window position to make the second coil layer (105) of one winding composite unit (1) and the first coil layer (101) of another winding composite unit (1) connected in series. Step Six: Integrated Forming of the Whole Board: After completing multi-layer stacking and welding, a complete ultra-large winding whole board substrate is formed. All welding nodes are uniformly located in the inner area of ​​the substrate, and the welding points in the same layer are staggered. The overall board surface is flat and uniform. Step 7: Matrix-style batch cutting: Perform matrix-style batch cutting according to the target winding specifications to obtain multiple standardized metal foil composite winding blanks in one batch; Step 8: Insulation Testing and Finishing: Insulation performance, conductivity, and flatness of the cut individual winding blanks are tested to complete the finished product preparation.

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