Manufacturing method of semi-embedded copper sheet large-current circuit board for connected car and circuit board

Abstract

A method for manufacturing a semi-embedded copper sheet high-current-carrying circuit board for connected vehicles is disclosed. This method integrates the circuit board body and the copper sheet through a semi-embedded copper sheet structure. The embedded section of the copper sheet is directly led out from the circuit board body. Utilizing the high conductivity of the copper sheet, efficient switching, conduction, and function conversion of high-current-carrying lines are achieved, significantly improving the circuit board's current-carrying capacity. This meets the high-voltage, high-current-carrying application requirements of intelligent connected vehicles and provides a new approach to the design and application of high-current-carrying circuit boards. Furthermore, this structure can replace traditional circuit board and wire designs, effectively solving problems such as complex wiring and large space occupation. It also reduces electromagnetic interference between wires, improves the heat dissipation efficiency of the circuit board, and allows high-current-carrying connection sections or independent control modules to be set up as separate circuit boards, achieving precise functional decomposition of the control circuit board and significantly reducing the functional integration and failure rate of the main control circuit board.

Description

Technical Field

[0001] This invention relates to the field of circuit board processing, and more particularly to a method for manufacturing a semi-embedded copper sheet high current-carrying circuit board for connected vehicles, and a circuit board. Background Technology

[0002] As the automotive industry undergoes a profound upgrade towards intelligence, connectivity, and electrification, the on-board electronic system architecture of intelligent connected vehicles is becoming increasingly complex. Core modules such as autonomous driving perception, power battery management, high-voltage power distribution, and motor drive control all need to achieve high current-carrying and high-voltage power transmission and signal control within a limited vehicle space. This places extremely high demands on the current-carrying capacity of circuit boards and whether they can achieve effective conversion control.

[0003] Currently, the industry generally adopts a combination of control circuit boards and wires to meet this need. The wires are connected to the control circuit board by plugging and soldering. The circuit board completes the regulation and conversion of current, and the wires realize the conduction and transmission of large current.

[0004] However, in the practical application of this traditional combination solution in intelligent connected vehicles, it has exposed many intractable technical defects and application problems: (1) Due to the miniaturized and modular design features of the vehicle space, the wiring process is complicated. If it is connected to the control circuit board, it will further increase the complexity of the overall wiring, not only occupying too much vehicle space, but also causing the dense wire layout to cause heat accumulation, making it difficult to dissipate heat in time, affecting the working stability and service life of the circuit components. (2) In order to adapt to the functional requirements of multiple modules, the functional integration of the control circuit board has been greatly improved, resulting in a high concentration of circuit nodes and functional modules on the board, a significant increase in the overall failure rate, and the structure makes it difficult to accurately locate and separate faults. Once a circuit fault occurs, the entire control circuit board often needs to be replaced, making it impossible to perform targeted repairs and component replacements, leading to increased application risks and costs.

[0005] Based on the above background and problems, there is a need to provide a novel method for manufacturing a semi-embedded copper sheet high current-carrying circuit board for connected vehicles, as well as a circuit board. Summary of the Invention

[0006] This invention aims to solve the comprehensive problems of high failure rate and heat accumulation in existing circuit boards due to their compact size and numerous modules. It provides a method for manufacturing a semi-embedded copper sheet high-current-carrying circuit board for connected vehicles. The circuit board is manufactured according to design data, and the copper sheet includes exposed and embedded sections. The manufacturing method includes the following steps: S10: Take a first copper-clad laminate with a first copper layer, a first prepreg, and a second copper-clad laminate with a second copper layer, and stack them in sequence to form a first stacked structure. S20: Drill pin holes in the first stacked structure, then use pins to fix each layer to the drilling table through the pin holes, then drill target holes, the first prepreg forms the first target hole prepreg, the first copper clad laminate forms the first target hole copper clad laminate, the second copper clad laminate forms the second target hole copper clad laminate, and the whole forms a drilled stacked structure. S30: A first window is made on the first target hole prepreg corresponding to the size of the copper sheet to form a windowed prepreg; S40: The first target hole copper-clad laminate, the windowed prepreg, the copper sheet, and the second target hole copper-clad laminate are stacked in sequence to form a second stacked structure, then pressed together to form a press plate, and then processed by subsequent processes to form the circuit board. The first copper layer and the second copper layer are located on the surface of the press plate, and the copper sheet is disposed in the first opening.

[0007] Furthermore, both the first copper layer and the second copper layer in the first stacked structure are disposed facing the first prepreg.

[0008] Furthermore, both the first copper-clad laminate and the second copper-clad laminate are double-sided copper-clad laminates. The first target hole copper-clad laminate includes a third copper layer, and the second target hole copper-clad laminate includes a fourth copper layer; Forming the second stacked structure includes creating a circuit pattern on the exposed section of the third copper layer corresponding to the copper sheet to form a first reverse copper pattern, and creating a circuit pattern on the fourth copper layer corresponding to the exposed section of the copper sheet to form a second reverse copper pattern. In the second stacked structure, both the first reverse copper pattern and the second reverse copper pattern face the copper sheet.

[0009] Further, forming the second stacked structure includes taking an adhesive layer, wherein one side of the size of the adhesive layer is less than or equal to the size of the copper sheet of the embedded section, and adhering the embedded section of the copper sheet to the surface of the first target hole copper clad laminate or the surface of the second target hole copper clad laminate using the adhesive layer.

[0010] Furthermore, forming the first stacked structure includes baking both the first copper-clad laminate and the second copper-clad laminate, and then stacking them sequentially to form the first stacked structure.

[0011] Furthermore, forming the first stacked structure also includes taking a third copper-clad laminate, etching all the copper layers, and forming an optical core board. Take the second semi-cured sheet. The first copper-clad laminate, the first prepreg, the optical core board, the second prepreg, and the second copper-clad laminate are stacked sequentially to form the first stacked structure. Forming the drilled stack structure includes drilling target holes in the first stack structure, the first copper-clad laminate forming the first target hole copper-clad laminate, the first prepreg forming the first target hole prepreg, the optical core board forming the target hole optical core board, the second prepreg forming the second target hole prepreg, and the second copper-clad laminate forming the second target hole copper-clad laminate.

[0012] Furthermore, forming the second stacked structure includes, A second window is made on the target hole optical core plate corresponding to the copper sheet to form a windowed optical core plate; The first target hole copper-clad laminate, the first target hole prepreg, the windowed optical core board, the copper sheet, the second target hole prepreg, and the second target hole copper-clad laminate are stacked sequentially to form the second stacked structure; The copper sheet is disposed within the second window.

[0013] Furthermore, forming the second stacked structure includes, Take a first release tape and a second release tape, the size of the first release tape and the size of the second release tape both corresponding to the exposed section of the copper sheet; The first release tape is attached to the surface of the first target hole semi-cured sheet, and the second release tape is attached to the surface of the second target hole semi-cured sheet; In the second stacked structure, both the first release tape and the second release tape face the copper sheet.

[0014] Further, the post-processing includes drilling through holes and electroplating them sequentially on the press plate, forming through holes to form conductive holes, then sequentially fabricating surface circuit patterns, solder mask patterns and surface treatment, forming a surface-treated board, then controlling the depth of the exposed section of the copper sheet for milling, and then removing the cover, and finally forming the circuit board. The depth of the controlled-depth milling is from the surface of the surface treatment plate to the surface of the copper sheet.

[0015] The present invention also provides a circuit board, which is manufactured using any of the above-described manufacturing methods.

[0016] The main beneficial effects of this technical solution include: First, by designing an integrated structure with semi-embedded copper sheets, the circuit board body and the copper sheets are integrated. The exposed section of the copper sheet is directly led out from the circuit board body. Relying on the high conductivity of the copper sheet, efficient transfer, conduction, and functional conversion of high-current-carrying lines are achieved, significantly improving the current-carrying capacity of the circuit board. This meets the application requirements of high voltage and high current-carrying capacity in intelligent connected vehicles and provides a new approach to the design and application of high-current-carrying circuit boards. Simultaneously, this structure can replace the traditional circuit board and wire design, effectively solving problems such as complex wiring and large space occupation, reducing electromagnetic interference between wires, improving the heat dissipation efficiency of the circuit board, and setting high-current-carrying connection sections or independent control modules as separate circuit boards. This allows for precise functional decomposition of the control circuit board, significantly reducing the functional integration and failure rate of the main control circuit board. In case of failure, only the dedicated circuit board needs to be replaced, instead of replacing the entire board, significantly reducing subsequent maintenance costs and application risks.

[0017] Secondly, by stacking copper-clad laminates and prepregs in an orderly manner to form the first stack structure, and using a processing method of fixing with pins first and then drilling target holes as a whole, the target hole spacing and coaxial positioning reference of each layer of board are made uniform, eliminating the alignment error caused by drilling individual holes in a single layer of board, greatly improving the target hole processing accuracy. The produced target holes provide a high-precision positioning basis for subsequent processes such as window opening, copper sheet positioning, and stacking and pressing, ensuring the alignment consistency of each processing link, effectively improving the overall processing accuracy and product yield of the circuit board. At the same time, integrated drilling simplifies the processing flow and improves the overall processing efficiency.

[0018] Third, a core board is added to the stacked structure as a dedicated fixing medium layer for the copper sheets. After curing, the core board has high hardness and weak resin flow, which can provide stable support and limit for the copper sheets. This effectively avoids the copper sheets from shifting and warping due to the flow of resin in the medium layer during the pressing process, and greatly improves the positioning accuracy of copper sheet fixing and pressing. At the same time, the addition of the core board also enhances the overall rigidity and structural strength of the circuit board.

[0019] Fourth, a standardized full-process manufacturing system is constructed, from stacking, drilling, windowing, pressing to post-processing. Each process is closely connected and uses the target hole as a unified positioning reference, ultimately achieving high-precision processing of semi-embedded copper sheet high-current-carrying circuit boards for intelligent connected vehicles. The processing is highly controllable and the operation is standardized, which facilitates industrialized mass production. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, 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 the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a process flow diagram of an embodiment of the present invention; Figure 2 This is a plan view of the drilling stack structure according to an embodiment of the present invention; Figure 3 for Figure 2 Schematic diagram of AA section; Figure 4 This is a plan view of the second stacked structure according to an embodiment of the present invention; Figure 5 for Figure 4 Schematic diagram of the BB cross section; Figure 6 for Figure 4 Schematic diagram of the CC section; Figure 7 for Figure 4 Schematic diagram of the DD cross section; Figure 8 This is a schematic diagram of the cross-sectional structure of the press plate formed by the BB section after pressing; Figure 9 This is a schematic diagram of the cross-sectional structure of the press plate formed by the CC section after pressing. Figure 10 This is a cross-sectional schematic diagram of another borehole stack structure according to an embodiment of the present invention; Figure 11 This is a plan view of another second stacked structure according to an embodiment of the present invention; Figure 12 for Figure 11 Schematic diagram of the EE cross section; Figure 13 for Figure 11 Schematic diagram of the FF cross section; Figure 14 for Figure 11 Schematic diagram of the GG cross section; Figure 15 This is a schematic diagram of the cross-sectional structure of another press plate formed by the EE section after pressing; Figure 16 This is a schematic diagram of the cross-sectional structure of another press plate formed by the FF cross section after pressing; Figure 17 This is a cross-sectional schematic diagram of the circuit board according to an embodiment of the present invention; Figure 18 for Figure 17 Schematic diagram of the HH cross section; Figure 19 This is a physical schematic diagram of the circuit board according to an embodiment of the present invention.

[0022] Reference numerals: 10, Drilled stacked structure; 1010, Pin; 1020, Target hole; 1030, First target hole copper-clad laminate; 1031, First dielectric layer; 1032, First copper layer; 1040, First target hole prepreg; 1050, Second target hole copper-clad laminate; 1051, Second copper layer; 1052, Second dielectric layer; 20, Second stacked structure; 2010, Stacked area; 2020, Windowed prepreg; 2030, Copper sheet; 2031, Embedded section; 2032, Exposed section; 2040, Adhesive layer; 2050... First reverse copper pattern; 2060, second reverse copper pattern; 2070, depth control groove; 30, laminating plate; 10A, another drilling stacked structure; 1060, target hole core board; 1070, second target hole prepreg; 20A, another second stacked structure; 2080, windowed core board; 2091, first release tape; 2092, second release tape; 30A, another laminating plate; 40, circuit board; 4010, circuit board through hole; 4020, copper sheet through hole; 4030, copper sheet solder pad through hole; 4040, solder resist pattern.

[0023] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0026] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0028] To better understand the above technical solution, the following detailed explanation is provided in conjunction with the accompanying drawings.

[0029] Please see Figure 1 , Figure 1 This is a process flow diagram of an embodiment of the present invention.

[0030] The semi-embedded copper sheet 2030 high-current-carrying circuit board 40 for connected vehicles in this embodiment is manufactured according to design data. The circuit board 40 includes an effective area for laying functional circuits and an ineffective area (i.e., a tooling area) that needs to be cut off during final forming. The copper sheet 2030 includes an exposed section 2032 and an embedded section 2031. The manufacturing method includes... Figure 1 The process flow diagram is as follows.

[0031] Please see Figure 2 and Figure 3 , Figure 2 This is a plan view of the drilling stack structure according to an embodiment of the present invention; Figure 3 for Figure 2 A schematic diagram of the AA section.

[0032] Step S10: A first copper-clad laminate with a first copper layer 1032, a first prepreg, and a second copper-clad laminate with a second copper layer 1051 are stacked sequentially to form a first stacked structure (not shown in the attached figure).

[0033] By stacking the above-mentioned interlayer structures in an orderly manner, an integrated basic layered structure for processing the circuit board 40 is constructed, providing a unified processing substrate for subsequent drilling processes such as drilling pin holes and drilling target holes 1020.

[0034] Furthermore, in the first stacked structure, both the first copper layer 1032 and the second copper layer 1051 are disposed facing the first prepreg.

[0035] The first copper layer 1032 and the second copper layer 1051 are both arranged inwards. This is an optimization of the drill bit layout for the subsequent drilling of the target hole 1020. When the drill bit enters the hole, it first contacts the first medium layer 1031, which has a texture more suitable for the drill bit's cutting. This avoids direct contact with the high-hardness first copper layer 1032, which would generate excessive friction and cause structural damage such as cracking, delamination, and warping. Furthermore, when the drill bit penetrates the entire first stacked structure, it finally penetrates the second medium layer 1052, rather than the second copper layer 1051. This can also effectively avoid the strong pulling force and cutting burr problems that are easily generated when drilling through the copper layer.

[0036] Furthermore, forming the first stacked structure includes baking the first copper-clad laminate and the second copper-clad laminate, and then stacking them sequentially to form the first stacked structure.

[0037] Baking effectively releases the internal stress of the first and second copper-clad laminates, improves the dimensional stability of the board itself, avoids problems such as interlayer alignment deviation and hole offset caused by board expansion and contraction deformation during subsequent processing, ensures the accuracy of stacking and drilling, and the surface flatness of the copper-clad laminate after baking is better, and the interlayer bonding after stacking is tighter, which can lay the foundation for the structural stability of the overall processing in the future.

[0038] Optionally, the baking temperature of the baking plate is 120℃ to 150℃, and the baking time is 20 minutes to 60 minutes. This can ensure the release of internal stress and avoid damage to the bonding force between the dielectric layer and the copper layer caused by high temperature and long-term treatment, thus preventing defects such as board warping and copper layer peeling.

[0039] Step S20: Drill pin holes in the ineffective area of ​​the first stacked structure, and then use pins 1010 to fix each layer to the drilling table through the pin holes. Then drill target holes 1020, the first semi-cured sheet forms the first target hole semi-cured sheet 1040, the first copper clad laminate forms the first target hole copper clad laminate 1030, and the second copper clad laminate forms the second target hole copper clad laminate 1050, thus forming the drilled stacked structure 10.

[0040] By drilling pin holes and using pins 1010, the rigid fixing of each layer of the first stacked structure is achieved, ensuring the alignment consistency of each board when drilling the target hole 1020. This makes the first copper-clad laminate, the first prepreg, and the second copper-clad laminate form a unified target hole spacing and coaxial positioning reference, avoiding the cumulative alignment error caused by drilling individual holes in a single layer of board. This provides high-precision positioning conditions for all subsequent processes based on the target hole 1020, such as window opening, precise positioning of copper sheet 2030, and stacking and pressing. Furthermore, it also relies on the overall stacked structure to complete two types of drilling, simplifying the processing flow and improving processing efficiency.

[0041] It is worth noting that the pin holes are simple positioning holes machined in the ineffective area of ​​the first stacked structure. They do not have high precision requirements and only serve to fix the layers of boards. After the pins 1010 firmly fix the layers to the drilling table, high-precision target holes 1020 are drilled according to the design requirements. The pin holes are set in the ineffective area and will not occupy the space of the effective area of ​​the circuit board 40, thus not affecting its subsequent electrical performance and structural layout.

[0042] Please refer to the following: Figures 4 to 7 , Figure 4 This is a plan view of the second stacked structure according to an embodiment of the present invention; Figure 5 for Figure 4 Schematic diagram of the BB cross section; Figure 6 for Figure 4 A schematic diagram of the CC section; Figure 7 for Figure 4 Schematic diagram of the DD cross section.

[0043] Step S30: A first window is made on the copper sheet 2030 corresponding to the size of the first target hole prepreg 1040, forming a windowed prepreg 2020.

[0044] Using the target hole 1020 as a high-precision positioning reference, the first window is precisely made according to the actual size of the copper sheet 2030. Structurally, space is reserved for the placement of the copper sheet 2030. In the subsequent pressing process, the displacement of the copper sheet 2030 can be effectively restricted, ensuring the positional accuracy of the copper sheet 2030 embedded in the board after pressing. This lays the structural foundation for the high current carrying capacity and structural stability of the subsequent circuit board 40.

[0045] Please continue reading. Figures 4 to 7 Please see also Figure 8 and Figure 9 ; Figure 8 This is a schematic diagram of the cross-sectional structure of the press plate formed by the BB section after pressing; Figure 9 This is a schematic diagram of the cross-sectional structure of the press plate formed by the CC section after pressing.

[0046] Step S40: The first target hole copper clad laminate 1030, the windowed prepreg 2020, the copper sheet 2030, and the second target hole copper clad laminate 1050 are stacked sequentially to form a second stacked structure 20 (including a stacked area 2010). These are then laminated to form a laminated plate 30, which is further processed to form a circuit board 40. The first copper layer 1032 and the second copper layer 1051 are located on the surface of the laminated plate 30, and the copper sheet 2030 is disposed within the first window (e.g., ...). Figure 7 (As shown).

[0047] Based on the unified target hole 1020 positioning reference of each layer of board, the components are stacked in an orderly manner according to a predetermined order, so that the copper sheet 2030 is precisely embedded in the first window of the windowed semi-cured sheet 2020. Through the physical limiting effect of the window, the position of the copper sheet 2030 is fixed in space, avoiding horizontal displacement, angular skew, or vertical warping of the copper sheet 2030 during the stacking process. Then, the second stacked structure 20 is pressed to form an integrated press plate 30 with tight interlayer bonding and a solid structure, realizing the design structure of the copper sheet 2030 being semi-embedded in the board body.

[0048] Further, forming the second stacked structure 20 includes taking an adhesive layer 2040, wherein one side of the size of the adhesive layer 2040 is less than or equal to the size of the copper sheet 2030 of the embedded section 2031, and adhering the embedded section 2031 of the copper sheet 2030 to the surface of the first target hole copper clad laminate 1030 or the surface of the second target hole copper clad laminate 1050 using the adhesive layer 2040 (e.g., Figure 5 (As shown).

[0049] The adhesive layer 2040 is used to first adhere the embedded section 2031 to the surface of the first target hole copper clad laminate 1030 or the second target hole copper clad laminate 1050, so as to achieve precise pre-fixation of the copper sheet 2030 in the early stage and prevent problems such as misalignment and lamination misalignment caused by directly stacking the copper sheets 2030. The function of the adhesive layer 2040 is to fix the copper sheet 2030 to the surface of the first target hole copper clad laminate 1030 or the second target hole copper clad laminate 1050 before lamination. Therefore, it is sufficient to just play a fixing role.

[0050] Optionally, the adhesive layer 2040 is an epoxy resin adhesive or an acrylic adhesive. This type of adhesive layer 2040 has moderate adhesion and its material properties are close to those of the insulating dielectric layer material of the board itself. It can achieve stable pre-fixation between the copper sheet 2030 and the surface of the first target hole copper clad laminate 1030 or the surface of the second target hole copper clad laminate 1050, and it can also be adapted to the properties such as pressing heat performance and expansion and contraction performance during processing.

[0051] The size of the adhesive layer 2040 is less than or equal to the size of the copper sheet 2030 embedded in the section 2031 on one side, so that the adhesive layer 2040 is attached within the range of the copper sheet 2030, avoiding excessive adhesive overflow during pressing. The thickness of the adhesive layer 2040 is relatively thin, ranging from 5 micrometers to 35 micrometers, which can effectively adhere the copper sheet 2030 so that it does not shift excessively during pressing, while avoiding problems such as excessive adhesive overflow due to excessive thickness and mismatch in processing performance due to differences in material properties.

[0052] It is worth noting that forming the second stacked structure 20 includes, before stacking, first fabricating depth control grooves 2070 on the first dielectric layer 1031 of the first target hole copper clad laminate 1030 and the second dielectric layer 1052 of the second target hole copper clad laminate 1050 (e.g., ...). Figure 6 (As shown).

[0053] On the one hand, defining a precise depth reference for subsequent surface controlled-depth milling and peeling processes can effectively avoid the problems of excessive milling damaging the copper sheet 2030 body or the internal circuitry of the board, or insufficient milling depth leading to incomplete peeling. On the other hand, the structure of the controlled-depth groove 2070 can reduce the cutting resistance during milling, making the peeling of the surface material smoother, improving the efficiency and yield of peeling processes, and also ensuring the structural integrity of the exposed section 2032, laying a regular structural foundation for the subsequent edge trimming of the exposed section 2032 and the electrical connection of the entire circuit board 40.

[0054] Optionally, both the first and second copper-clad laminates are double-sided copper-clad laminates. The first target-hole copper-clad laminate 1030 includes a third copper layer, and the second target-hole copper-clad laminate 1050 includes a fourth copper layer. Forming the second stacked structure 20 includes fabricating a circuit pattern on the exposed section 2032 of the copper sheet 2030 corresponding to the third copper layer to form a first reverse copper pattern 2050, and fabricating a circuit pattern on the exposed section of the copper sheet 2030 corresponding to the fourth copper layer to form a second reverse copper pattern 2060 (e.g., ...). Figure 7 (As shown); in the second stacked structure, both the first reverse copper pattern 2050 and the second reverse copper pattern 2060 face the copper sheet 2030.

[0055] By precisely fabricating the first reverse copper pattern 2050 and the second reverse copper pattern 2060 at the positions of the exposed sections 2032 of the copper sheet 2030 corresponding to the third and fourth copper layers, the copper sheet 2030 and the two reverse copper patterns are tightly bonded to each other after the second stacked structure 20 is stacked, forming a "release" structural effect. This avoids excessive adhesion between the copper sheet 2030 and other layers of the copper-clad laminate, providing a core foundation for precise and smooth uncovering processing of the exposed sections 2032 of the copper sheet 2030 in subsequent deep milling processes. This ensures that the surface board can be precisely peeled off along the contours of the first reverse copper pattern 2050 and the second reverse copper pattern 2060 during milling, exposing the copper sheet 2030 without damaging its body.

[0056] Please see Figures 10 to 16 ; Figure 10 This is a cross-sectional schematic diagram of another borehole stacking structure according to an embodiment of the present invention. Figure 11 This is a plan view of another second stacked structure according to an embodiment of the present invention; Figure 12 for Figure 11 Schematic diagram of the EE cross section; Figure 13 for Figure 11 Schematic diagram of the FF cross section; Figure 14 for Figure 11 Schematic diagram of the GG cross section; Figure 15 This is a schematic diagram of the cross-sectional structure of another press plate formed by the EE section after pressing; Figure 16This is a schematic diagram of the cross-sectional structure of another press plate formed by the FF cross section after pressing.

[0057] In another embodiment, forming another first stacked structure further includes taking a third copper-clad laminate, etching all copper layers to form an optical core board, then taking a second prepreg, and stacking the first copper-clad laminate, the first prepreg, the optical core board, the second prepreg, and the second copper-clad laminate sequentially to form a first stacked structure; laminating to form another lamination board 30A, forming another drilled stacked structure 10A includes drilling target holes 1020 in the first stacked structure, the first copper-clad laminate forming a first target hole copper-clad laminate 1030, the first prepreg forming a first target hole prepreg 1040, the optical core board forming a target hole optical core board 1060, the second prepreg forming a second target hole prepreg 1070, and the second copper-clad laminate forming a second target hole copper-clad laminate 1050 (e.g., Figure 10 (As shown).

[0058] The addition of the optical core board serves two purposes. First, as a rigid core board with fully cured resin, its low fluidity and high hardness provide stable support and limiting conditions for the copper sheet 2030, which serves as a dedicated fixing medium layer. This effectively prevents the copper sheet 2030 from shifting or warping due to resin flow during the pressing process, significantly improving the positioning accuracy of the copper sheet 2030 during fixing and pressing. Second, it enhances the overall rigidity and structural strength of the circuit board 40, improving the structural reliability and service life of the semi-embedded copper sheet circuit board 40 under complex working conditions such as vehicle vibration. Moreover, the optical core board is not completely non-fluid; it can effectively bond with the semi-cured sheets on the upper and lower sides during pressing, ensuring interlayer bonding and avoiding problems such as interlayer separation and delamination.

[0059] The target hole core board 1060 is set as the middle layer of the stacked structure, so that the first stacked structure forms a symmetrical layered layout, which makes the stress on each layer of the board uniform during the drilling of the target hole. This improves the stability of the drilling operation from the structural level and effectively prevents problems such as the skewness of the target hole 1020 or the displacement of the hole position caused by uneven stress between layers. This further ensures the processing accuracy of the target hole 1020 and provides a higher precision positioning basis for subsequent processes such as window opening, copper sheet 2030 positioning and stacking based on the target hole 1020.

[0060] Furthermore, based on another stacked structure, forming another second stacked structure 20A includes: fabricating a second window on the copper sheet 2030 corresponding to the target hole optical core plate 1060 to form a windowed optical core plate 2080; sequentially stacking the first target hole copper-clad laminate 1030, the first target hole prepreg 1040, the windowed optical core plate 2080, the copper sheet 2030, the second target hole prepreg 1070, and the second target hole copper-clad laminate 1050 to form another second stacked structure 20A; wherein, the copper sheet 2030 is disposed within the second window (e.g., Figure 12 , Figure 13 and Figure 14 (As shown).

[0061] Using the target hole 1020 as a unified positioning reference, a second window is made on the target hole core plate 1060 to precisely match the size of the copper sheet 2030, making the windowed core plate 2080 a dedicated rigid fixing layer for the copper sheet 2030. Utilizing the characteristics of the core plate resin curing and high hardness, it provides a more stable limiting support for the copper sheet 2030. Compared with opening windows only on the semi-cured sheet, the positioning and fixing effect of the copper sheet 2030 is more accurate, effectively avoiding the copper sheet 2030 from shifting, warping or moving during stacking and pressing.

[0062] Specifically, the interlayer structures are stacked in a predetermined order, and the copper sheet 2030 is embedded in the second window. The physical positioning of the window achieves precise positioning of the copper sheet 2030. At the same time, the first target hole semi-cured sheet 1040 and the second target hole semi-cured sheet 1070 laid on the upper and lower sides can fully melt and form a good bonding effect with each layer of board and the copper sheet 2030 during the pressing process, ensuring the interlayer bonding force of the board and making the copper sheet 2030 and the circuit board 40 form a strong integrated structure. This structure combines the precise positioning advantage of the core board and the bonding characteristics of the semi-cured sheet, doubly ensuring the positional accuracy of the embedded copper sheet 2030, effectively improving the overall processing accuracy and structural reliability of the embedded copper sheet 2030, and providing stable structural support for the high current carrying capacity of the circuit board 40.

[0063] Further, forming another second stacked structure 20A includes taking a first release tape 2091 and a second release tape 2092, the dimensions of the first release tape 2091 and the second release tape 2092 both corresponding to the exposed section 2032 of the copper sheet 2030; attaching the first release tape 2091 to the surface of the first target hole semi-cured sheet 1040, and attaching the second release tape 2092 to the surface of the second target hole semi-cured sheet 1070; in the other second stacked structure 20A, both the first release tape 2091 and the second release tape 2092 face the copper sheet 2030 (e.g., Figure 13 and Figure 14 (As shown).

[0064] By selecting a first release tape 2091 and a second release tape 2092 that precisely match the size of the exposed section 2032, the precise area for release processing can be limited to the corresponding position of the exposed section 2032.

[0065] During the pressing process, the first release tape 2091 and the second release tape 2092 can effectively block the exposed section 2032 of the copper sheet 2030 from the molten first target hole semi-cured sheet 1040 and the second target hole semi-cured sheet 1070. This can effectively prevent the exposed section 2032 of the copper sheet 2030 from sticking and causing difficulties in subsequent capping, and provide a smooth release foundation for the subsequent controlled depth milling of the exposed copper sheet 2030.

[0066] Furthermore, the forming process includes milling or laser trimming the edges of the exposed section 2032 of the copper sheet 2030.

[0067] By milling or laser finishing the edges of the exposed section 2032, impurities such as adhesive residue or excess adhesive that adhered to the edges of the copper sheet 2030 during the pressing process can be completely removed, preventing the adhesive layer 2040 residue from affecting the conductivity of the copper sheet 2030 and the contact effect of subsequent electrical connections. At the same time, it can precisely smooth out burrs, warped edges, irregular protrusions and other defects caused by processing on the edges of the copper sheet 2030, improving the flatness and regularity of the exposed section 2032 edges and ensuring the fitting accuracy when it is connected to external components.

[0068] Please see Figure 17 and Figure 18 ; Figure 17 This is a cross-sectional schematic diagram of the circuit board according to an embodiment of the present invention. Figure 18 for Figure 17 A schematic diagram of the HH cross section.

[0069] After the above-mentioned post-processing steps, circuit board 40 is formed.

[0070] Further, the subsequent processing includes drilling through holes and electroplating the press plate 30 in sequence, forming through holes (including circuit board through holes 4010, copper sheet through holes 4020 and copper sheet solder pad through holes 4030), then sequentially creating surface circuit patterns, solder mask patterns 4040 and surface treatment, forming a surface-treated board, then controlling the depth of the exposed section 2032 of the copper sheet 2030 for milling, and then removing the cover, and finally forming the board to form the circuit board 40; wherein, the depth of the controlled milling is from the surface of the surface-treated board to the surface of the copper sheet 2030.

[0071] Through holes are formed on the lamination board 30 to achieve electrical connectivity between the layers of the circuit board 40, ensuring the realization of the electrical functions of the circuit board 40. Then, surface circuit patterns are made to match the circuit control requirements of intelligent connected vehicles. Solder mask patterns 4040 are used to isolate the circuits and prevent short circuits and oxidation. After that, surface treatment improves the wear resistance, corrosion resistance and high temperature resistance of the circuit board 40 surface, adapting to the complex working conditions of vehicle vibration and high and low temperature alternation, greatly improving the environmental adaptability and service life of the circuit board 40. Then, the exposed section 2032 of the copper sheet 2030 is precisely milled with controlled depth, and the milling depth is strictly controlled from the surface of the surface treatment board to the position of the copper sheet 2030 to achieve precise uncovering. Finally, the whole board is formed so that the circuit board 40 achieves the designed shape and dimensional accuracy, completing the overall processing and manufacturing of the circuit board 40.

[0072] Please see Figure 19 ; Figure 19 This is a physical schematic diagram of the circuit board according to an embodiment of the present invention.

[0073] This embodiment also provides a circuit board, which is manufactured in the above manner. Through the semi-embedded integrated structure of copper sheet 2030, it realizes efficient transfer and conduction of high current-carrying lines, significantly improves current carrying capacity, and can meet the application requirements of high voltage and high current of intelligent connected vehicles. It has high processing precision and strong reliability.

[0074] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made under the inventive concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for manufacturing a semi-embedded copper sheet high-current-carrying circuit board for connected vehicles, wherein the circuit board is fabricated according to design data, characterized in that... The copper sheet includes an exposed section and an embedded section, and the manufacturing method includes the following steps: S10: Take a first copper-clad laminate with a first copper layer, a first prepreg, and a second copper-clad laminate with a second copper layer, and stack them in sequence to form a first stacked structure. S20: Drill pin holes in the first stacked structure, then use pins to fix each layer to the drilling table through the pin holes, then drill target holes, the first prepreg forms the first target hole prepreg, the first copper clad laminate forms the first target hole copper clad laminate, the second copper clad laminate forms the second target hole copper clad laminate, and the whole forms a drilled stacked structure. S30: A first window is made on the first target hole prepreg corresponding to the size of the copper sheet to form a windowed prepreg; S40: The first target hole copper-clad laminate, the windowed prepreg, the copper sheet, and the second target hole copper-clad laminate are stacked in sequence to form a second stacked structure, then pressed together to form a press plate, and then processed by subsequent processes to form the circuit board. The first copper layer and the second copper layer are located on the surface of the laminating plate, and the copper sheet is disposed in the first opening.

2. The manufacturing method as described in claim 1, characterized in that, In the first stacked structure, both the first copper layer and the second copper layer are positioned facing the first prepreg.

3. The manufacturing method as described in claim 2, characterized in that, Both the first and second copper-clad laminates are double-sided copper-clad laminates. The first target hole copper-clad laminate includes a third copper layer, and the second target hole copper-clad laminate includes a fourth copper layer; Forming the second stacked structure includes creating a circuit pattern on the exposed section of the third copper layer corresponding to the copper sheet to form a first reverse copper pattern, and creating a circuit pattern on the fourth copper layer corresponding to the exposed section of the copper sheet to form a second reverse copper pattern. In the second stacked structure, both the first reverse copper pattern and the second reverse copper pattern face the copper sheet.

4. The manufacturing method as described in claim 1 or 3, characterized in that, Forming the second stacked structure includes taking an adhesive layer, wherein one side of the size of the adhesive layer is less than or equal to the size of the copper sheet of the embedded section, and adhering the embedded section of the copper sheet to the surface of the first target hole copper clad laminate or the surface of the second target hole copper clad laminate using the adhesive layer.

5. The manufacturing method as described in claim 4, characterized in that, Forming the first stacked structure includes baking both the first copper-clad laminate and the second copper-clad laminate, and then stacking them sequentially to form the first stacked structure.

6. The manufacturing method as described in claim 1, characterized in that, The formation of the first stacked structure also includes taking a third copper-clad laminate, etching all the copper layers, and forming an optical core board. Take the second semi-cured sheet. The first copper-clad laminate, the first prepreg, the optical core board, the second prepreg, and the second copper-clad laminate are stacked sequentially to form the first stacked structure. Forming the drilled stack structure includes drilling target holes in the first stack structure, the first copper-clad laminate forming the first target hole copper-clad laminate, the first prepreg forming the first target hole prepreg, the optical core board forming the target hole optical core board, the second prepreg forming the second target hole prepreg, and the second copper-clad laminate forming the second target hole copper-clad laminate.

7. The manufacturing method as described in claim 6, characterized in that, The formation of the second stacked structure includes, A second window is made on the target hole optical core plate corresponding to the copper sheet to form a windowed optical core plate; The first target hole copper-clad laminate, the first target hole prepreg, the windowed optical core board, the copper sheet, the second target hole prepreg, and the second target hole copper-clad laminate are stacked sequentially to form the second stacked structure; The copper sheet is disposed within the second window.

8. The manufacturing method as described in claim 7, characterized in that, Forming the second stacked structure includes, Take a first release tape and a second release tape, the size of the first release tape and the size of the second release tape both corresponding to the exposed section of the copper sheet; The first release tape is attached to the surface of the first target hole semi-cured sheet, and the second release tape is attached to the surface of the second target hole semi-cured sheet; In the second stacked structure, both the first release tape and the second release tape face the copper sheet.

9. The manufacturing method as described in claim 1, characterized in that, The subsequent processing includes drilling through holes and electroplating them sequentially on the press plate, forming through holes to form conductive holes; then sequentially fabricating surface circuit patterns, solder mask patterns, and surface treatments to form a surface-treated plate; then controlling the depth of the exposed section of the copper sheet during milling and removing the cover; and finally forming the circuit board. The depth of the controlled-depth milling is from the surface of the surface treatment plate to the surface of the copper sheet.

10. A circuit board, characterized in that, The circuit board is manufactured using the manufacturing method described in any one of claims 1 to 9.

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