Double-sided copper-embedded double-sided circuit board with symmetrical structure and preparation method thereof

Abstract

The invention relates to the technical field of circuit board preparation, and particularly discloses a double-sided circuit board with a double-sided copper-embedded symmetrical structure and a preparation method thereof, and the method comprises the steps: providing and processing a first copper-clad core board and a second copper-clad core board, and forming an etched core board through pattern transfer and etching; carrying out board milling treatment on the copper embedding area of the etched core board; preparing a copper block, and carrying out brownification drying on the copper block and the core plate after milling; laminating and laminating the pretreated core plate and the copper block by using a polyimide film to form a substrate laminated structure; and finally, completing the preparation of the circuit board based on the structure. The accuracy of a copper embedding area can be ensured through a routing processing mode, the bonding force between copper and a base material is enhanced through browning processing, the stability and the mechanical strength of the whole circuit board structure can be effectively enhanced by utilizing a polyimide film to perform lamination processing, meanwhile, buffering is provided for the difference of thermal expansion coefficients between different materials, and the reliability of the circuit board structure is improved. And the layering or fracture problem caused by temperature change is prevented.

Description

Technical Field

[0001] The present application relates to the technical field of circuit board preparation, and more specifically, to a double-sided circuit board with a double-sided copper embedded symmetrical structure and a preparation method thereof. Background Art

[0002] In the electronics manufacturing industry, circuit boards are the basic structures that carry and connect various electronic components. Their performance and quality play a vital role in the reliability of the entire electronic product. As electronic equipment develops towards miniaturization and multifunctionality, traditional single-layer or double-layer PCBs (Printed Circuit Boards) are difficult to meet the needs of some high-power, high-current-carrying, and efficient heat dissipation application scenarios. In order to cope with these problems, the industry gradually adopts thick copper foil (2 ounces or more) to make circuit boards to enhance current carrying capacity and heat dissipation effects.

[0003] However, in practical applications, when the line width does not match the copper thickness or cost considerations do not allow the use of an overall thick copper design, manufacturers usually adopt a method of partially embedding copper blocks / copper bars to solve this contradiction. This method can provide higher current density and better heat conduction paths in specific areas while keeping the line fineness of other parts unchanged, thereby achieving a more economical and efficient solution. However, the current conventional embedded copper block / copper bar process still faces many challenges, such as overflow, uneven surface, pressure loss and insufficient bonding force, which greatly hinder the application of this process. In addition, traditional double-sided circuit boards are usually covered with a thin layer of copper foil on both sides, and then the required circuit pattern is formed by etching and other processes. However, as electronic devices develop towards miniaturization and high performance, traditional double-sided circuit boards are gradually unable to meet the needs of some special application scenarios. For example, when good heat dissipation performance or carrying large currents are required, ordinary copper cladding layers and asymmetric circuit patterns may not provide sufficient conductivity or thermal conductivity.

[0004] Therefore, an optimized preparation scheme for a double-sided circuit board with a double-sided copper embedded symmetrical structure is desired. Summary of the invention

[0005] The present application provides a double-sided copper-embedded symmetrical structure double-sided circuit board and its preparation method, which can ensure the accuracy of the copper-embedded area through gong plate processing, enhance the bonding force between copper and substrate through browning treatment, and effectively enhance the stability and mechanical strength of the entire circuit board structure through lamination treatment using polyimide film, while also providing a buffer for the difference in thermal expansion coefficients between different materials, preventing delamination or fracture problems caused by temperature changes.

[0006] In a first aspect, a method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure is provided, comprising: Providing a first copper clad core board and a second copper clad core board; Performing pattern transfer and etching treatment on the first copper clad core board and the second copper clad core board to obtain a first etched copper clad core board and a second etched copper clad core board; Performing lamination treatment on the copper embedded areas of the first etched copper clad core board and the second etched copper clad core board to obtain a first lamination copper clad core board and a second lamination copper clad core board; Provide copper blocks; The first copper clad core board after the gong plate, the second copper clad core board after the gong plate and the copper block are subjected to browning treatment and drying to obtain a first pre-treated copper clad core board, a second pre-treated copper clad core board and a pre-treated copper block; Based on the polyimide film, the first pretreated copper clad core board, the second pretreated copper clad core board and the pretreated copper block are laminated to obtain a circuit board substrate laminated structure; Based on the circuit board substrate laminated structure, a double-sided circuit board with a double-sided copper embedded symmetrical structure is prepared.

[0007] In a second aspect, a double-sided circuit board with a symmetrical structure and double-sided copper embedded on both sides is provided. The double-sided circuit board with a symmetrical structure and double-sided copper embedded on both sides is prepared by the preparation method of the double-sided circuit board with a symmetrical structure and double-sided copper embedded on both sides as described in the first aspect.

[0008] The present application provides a double-sided copper-embedded symmetrical structure double-sided circuit board and its preparation method, which can ensure the accuracy of the copper-embedded area through gong plate processing, enhance the bonding force between copper and substrate through browning treatment, and use polyimide film for lamination treatment to effectively enhance the stability and mechanical strength of the entire circuit board structure. At the same time, it also provides a buffer for the difference in thermal expansion coefficients between different materials, preventing delamination or fracture problems caused by temperature changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments of the present application are briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present application, and are not intended to limit the present application.

[0010] Figure 1 This is a schematic flow chart of a double-sided copper embedded symmetrical structure double-sided circuit board and a preparation method thereof according to an embodiment of the present application.

[0011] Figure 2 It is a schematic flow chart of step S6 in the double-sided copper embedded symmetrical structure double-sided circuit board and its preparation method according to an embodiment of the present application.

[0012] Figure 3 This is a schematic flow chart of step S2 in a double-sided copper embedded symmetrical structure double-sided circuit board and a preparation method thereof according to an embodiment of the present application.

[0013] Figure 4 It is a schematic flow chart of step S24 in the double-sided copper embedded symmetrical structure double-sided circuit board and its preparation method according to an embodiment of the present application. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.

[0015] In view of the above technical problems, in the technical solution of the present application, a method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure is proposed, such as Figure 1 As shown, the preparation method of the double-sided copper-embedded symmetrical structure double-sided circuit board comprises: S1, providing a first copper-clad core board and a second copper-clad core board; S2, performing pattern transfer and etching treatment on the first copper-clad core board and the second copper-clad core board to obtain a first etched copper-clad core board and a second etched copper-clad core board; S3, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second etched copper-clad core board to obtain a first gonged copper-clad core board and a second gonged copper-clad core board; S4, providing a copper block; S5, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second etched copper-clad core board to obtain a first gonged copper-clad core board and a second gonged copper-clad core board; S6, providing a copper block; S7, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second etched copper-clad core board to obtain a first gonged copper-clad core board and a second gonged copper-clad core board; S8, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second gonged copper-clad core board; S9, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second gonged copper-clad core board; S10, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second gonged copper-clad core board; S11, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second gonged copper-clad core board; S12, performing gong treatment on the copper-embedded areas of the first etched copper-clad core board and the second gonged copper-cla 5. The first copper clad core board after gong plate, the second copper clad core board after gong plate and the copper block are subjected to browning treatment and dried to obtain the first pre-treated copper clad core board, the second pre-treated copper clad core board and the pre-treated copper block; S6. Based on the polyimide film, the first pre-treated copper clad core board, the second pre-treated copper clad core board and the pre-treated copper block are subjected to lamination treatment to obtain a circuit board substrate lamination structure; S7. Based on the circuit board substrate lamination structure, a double-sided circuit board with a double-sided copper-embedded symmetrical structure is prepared. In the preparation method of the double-sided circuit board with a double-sided copper-embedded symmetrical structure, the accuracy of the copper-embedded area can be ensured by gong plate treatment, the browning treatment enhances the bonding force between copper and the substrate, and the lamination treatment using polyimide film can effectively enhance the stability and mechanical strength of the entire circuit board structure, while also providing a buffer for the difference in thermal expansion coefficients between different materials to prevent delamination or fracture problems caused by temperature changes.

[0016] Exemplarily, in step S1, a first copper clad core board and a second copper clad core board are provided. That is, first, a suitable copper clad core board material is selected according to the design specifications. In order to ensure good electrical performance, mechanical strength and thermal management capabilities, a substrate with excellent insulation performance and stability such as FR-4 is usually selected, and a certain thickness of copper foil is covered on both sides. Taking into account the specific needs of the application, such as for high-power or high heat dissipation requirements, it may be preferred to use thick copper foil (such as 2 ounces or thicker), or plan to locally bury additional copper blocks / copper bars in certain areas to enhance current carrying capacity and heat dissipation efficiency. Cut two copper clad core boards according to precise design dimensions. This process requires the use of high-precision cutting equipment, such as a laser cutting machine or a CNC milling machine (CNC), to ensure that the cut is smooth and burr-free, and the dimensional error is controlled within a very small range (such as ±0.05mm).

[0017] In addition, to facilitate positioning and operation in subsequent processes, each core board should be marked with clear direction identification and numbering for easy tracking and management. After the cutting is completed, the newly cut edges are immediately processed to remove any defects that may affect the subsequent processes, such as sharp edges or residues. Subsequently, the copper clad core board is fully inspected for quality, focusing on the consistency of copper foil thickness, surface flatness, and the presence of defects (such as scratches, unevenness). Only high-quality copper clad core boards that have passed strict screening can proceed to the next step - pattern transfer and etching.

[0018] Exemplarily, in step S2, the first copper clad core board and the second copper clad core board are subjected to pattern transfer and etching treatment to obtain a first etched copper clad core board and a second etched copper clad core board. That is, on the prepared first copper clad core board and the second copper clad core board, the pre-designed circuit pattern needs to be accurately transferred to the surface of the substrate. This step is usually completed by photolithography film or direct imaging technology. Then, an ultraviolet light exposure machine is used to irradiate these patterns onto the copper clad core board coated with a photosensitive resist. After exposure, the part of the resist that is not exposed to light will undergo chemical changes to form a protective film, while the rest of the part remains soluble in the developer. Next, the core board is placed in the developer to remove the resist in the unexposed area and expose the copper foil underneath, which is the so-called "development" process.

[0019] After the development is complete, the next crucial step is etching. At this stage, the core board will be immersed in a specially formulated etching solution, such as strong oxidants such as ferric chloride or ammonium persulfate. These chemicals can selectively dissolve the exposed copper layer without affecting the part covered by the resist. In order to ensure uniform etching effect, the etching time and temperature parameters must be strictly controlled, and the solution must be continuously circulated to avoid excessive corrosion caused by excessive local concentration.

[0020] In addition, spray etching equipment can also be used to spray etching liquid onto the surface of the core board using a high-pressure nozzle, which can not only speed up the reaction speed, but also further improve the etching accuracy. When the etching process is over, the continuous copper foil originally covering the entire copper clad core board has been processed into a complex circuit pattern, forming the first etched copper clad core board and the second etched copper clad core board. At this time, the residual resist needs to be completely removed, generally by cleaning agents or mechanical brushing. The cleaned core board should not have any visible traces of resist, and the edges of the copper wires should be smooth and neat, without obvious burrs or defects.

[0021] In one embodiment, in performing pattern transfer and etching on the first copper clad core board and the second copper clad core board to obtain a first etched copper clad core board and a second etched copper clad core board, the size of the gong plate is 0.05 mm-0.075 mm larger than the copper block.

[0022] Exemplarily, in step S3, the copper-embedded areas of the first etched copper-clad core board and the second etched copper-clad core board are subjected to grooving treatment to obtain the first grooved copper-clad core board and the second grooved copper-clad core board. It should be understood that after the pattern transfer and etching process are completed, the two copper-clad core boards have formed the required circuit pattern. At this time, for the position where the copper block needs to be embedded, part of the substrate must be accurately removed to reserve a suitable space for the copper block. In order to achieve this, it is very necessary to use grooving (also known as milling groove or hollowing) technology. The grooving equipment can be a CNC milling machine (CNC), which can automatically perform high-precision cutting tasks according to a preset program to ensure that the size and shape of each copper-embedded area strictly meet the design requirements. In actual operation, the technician will fix the etched copper-clad core board on a stable platform to ensure that it will not be displaced during the entire processing process.

[0023] Then, the core board is firmly fixed with a special fixture to prevent processing deviation caused by vibration or other external factors. Next, the gong plate path is generated by computer-aided design (CAD) software and imported into the CNC milling machine. These paths accurately indicate the specific location, depth and edge contour of the material to be removed, so as to ensure that each copper embedding area can perfectly match the copper block to be embedded. During the gong plate process, it is important to maintain appropriate cutting speed and feed rate, which helps to reduce heat generation and avoid material deformation. At the same time, in order to prevent dust and other impurities from contaminating the work area, an effective dust collection system should be equipped to clean up the generated debris in time. In addition, in order to ensure that the edges of the copper embedding area are smooth and neat, a grinding wheel or grinding head is usually used after the gong plate is completed to perform a slight grinding to remove possible burrs or unevenness. This additional treatment not only improves the convenience of operation when the copper block is embedded later, but also increases the contact area between the two, thereby improving the bonding strength. When the gong plate treatment is completed, the copper embedding area on each copper-clad core board is ready for the next step of browning and drying. It is worth noting that in order to ensure the consistency between the two copper-clad core boards, the gong board operation should be carried out as synchronously as possible, or at least completed under the same conditions. This can minimize the impact of any minor differences and ensure that the final double-sided copper-embedded symmetrical structure has a high degree of balance and stability.

[0024] Exemplarily, in step S4, a copper block is provided. That is, an appropriate copper material is selected according to the design requirements. For application scenarios that require high electrical conductivity and good thermal conductivity, electrolytic copper with higher purity (such as C1020 or C1100) is usually selected because such materials have excellent electrical properties and mechanical processing properties. In addition, considering the cost-effectiveness ratio and the matching of the thermal expansion coefficient with insulating substrates such as FR-4, nickel plating or other surface treatment methods are sometimes used to enhance the corrosion resistance and bonding strength of the copper block. In order to meet the needs of different sizes and shapes, the copper block can be a solid block, a bar or other customized forms.

[0025] Next, after determining the material of the copper block, it needs to be cut. This step is crucial because it is directly related to whether the copper block can be smoothly embedded in the pre-prepared copper clad core board. In order to ensure accuracy, CNC milling machines (CNC), laser cutting machines or stamping equipment are usually used for cutting. Regardless of the method, it is necessary to strictly follow the dimensions specified in the design drawings to ensure that the shape, thickness and edge processing of each copper block meet the standards. For example, the single-side size should be 0.05mm to 0.075mm larger than the gong space to facilitate placement without causing excessive gaps. In addition, in order to prevent the heat generated during the cutting process from affecting the quality of the copper block, it is recommended to use coolant-assisted processing and regularly check the tool status to avoid dimensional deviations due to wear.

[0026] Exemplarily, in step S5, the first gong plate copper clad core board, the second gong plate copper clad core board and the copper block are browned and dried to obtain the first pre-treated copper clad core board, the second pre-treated copper clad core board and the pre-treated copper block. It should be understood that after the gong plate treatment is completed, the precise space has been reserved for the copper block, and then these components need to be browned. Browning is a chemical treatment method that uses a specific chemical solution to generate a uniform and stable oxide film on the copper surface. This oxide film has good hydrophilicity and high activity, and can significantly improve the bonding strength between copper and the semi-cured sheet resin, thereby ensuring that no delamination or degumming occurs during the pressing process. In addition, the browning treatment can also play a certain anti-corrosion role and protect the copper material from environmental factors.

[0027] In order to ensure the consistency and reliability of the browning effect, the entire treatment process needs to be carried out under strict control conditions. First, the technicians will put the copper-clad core board and the cut copper blocks behind the gong plate into a specially designed browning tank. The browning tank is filled with pre-modulated browning liquid, which is usually composed of sulfuric acid, hydrogen peroxide and other additives. These ingredients work together on the copper surface to promote the formation of the required oxide film. The treatment time is generally set to range from a few minutes to more than ten minutes, depending on the formula of the browning liquid used and the thickness of the required oxide film. Throughout the process, the temperature of the browning liquid must be kept stable to avoid poor treatment effects due to temperature fluctuations.

[0028] After the browning treatment is completed, all components are dried immediately. The purpose of drying is to completely remove the residual moisture in the browning process to prevent bubbles or other quality problems that may occur in subsequent processes. To this end, a special oven or infrared drying equipment can be used for fast and uniform heating. The drying temperature is usually set between 80°C and 120°C, and the duration is from tens of minutes to hours. The specific parameters should be adjusted according to the actual materials used and the characteristics of the browning liquid. During this period, it is also necessary to check the status of the components regularly to ensure that no abnormal conditions such as deformation or discoloration occur. When the drying process is completed, the pretreated first copper clad core board, the second copper clad core board and the copper block are obtained. At this time, their surface is covered with a uniform browning film, which not only increases the bonding strength with the semi-cured sheet resin, but also has good corrosion resistance.

[0029] In one embodiment, Figure 2As shown, in step S6, based on the polyimide film, the first pretreated copper clad core board, the second pretreated copper clad core board and the pretreated copper block are laminated to obtain a circuit board substrate laminate structure, including: S61, attaching a first polyimide film on the copper foil of the first pretreated copper clad core board; S62, placing the pretreated copper block on the first polyimide film, wherein the pretreated copper block corresponds to the copper embedded area of ​​the first pretreated copper clad core board; S63, placing a predetermined number of prepregs on the pretreated copper block based on thickness requirements; S64, placing the second pretreated copper clad core board on the prepreg; S65, placing the pretreated copper block on the second pretreated copper clad core board; S66, placing a second polyimide film on the pretreated copper block to obtain a laminate structure; S67, pressing the laminate structure to obtain the circuit board substrate laminate structure.

[0030] In one embodiment, the thickness of the first polyimide film and the second polyimide film is 0.025 mm-0.05 mm.

[0031] It should be understood that before preparing for lamination, it is necessary to ensure that all components - including two pre-treated copper clad core boards and cut copper blocks - have been browned and dried, and a uniform and stable oxide film has been formed on the surface. These oxide films enhance the adhesion between copper and subsequent materials, while also providing good corrosion protection. Next, technicians will attach a polyimide film (PI film) with a thickness of 0.025mm to 0.05mm to the outer copper foil of the first pre-treated copper clad core board (L1 / L2). As a high-performance insulating material, PI film has excellent mechanical strength, thermal stability and electrical properties. It can effectively isolate different conductive layers and maintain its shape without deformation under high temperature and high pressure environments.

[0032] After the PI film is attached, the next step is to accurately place the pre-treated copper block on it. This step requires extremely high precision because the copper block must completely correspond to the hollow area and be in close contact with the surrounding substrate. In order to ensure the correct placement, a high-precision positioning device or a visual recognition system is usually used to assist the operation. When the copper block is in place, a predetermined number of prepregs are laid on top of the copper block according to design requirements. Generally, 2116 prepregs with a glue content of 55%-58% are selected. These prepregs have the function of filling gaps and leveling surfaces. At the same time, the resin components in them will flow and solidify during the subsequent lamination process to form a solid connection.

[0033] Subsequently, the second pre-treated copper clad core board (L3 / L4) is turned over so that L4 faces upwards, and a PI film is also attached to its outer side. Then, the above steps are repeated, another pre-treated copper block is placed on this copper clad core board, and the required prepreg is continued to be added. The purpose of this is to ensure that the copper embedded structure on the upper and lower sides is symmetrical and consistent, thereby improving the balance and stability of the entire circuit board. Finally, another PI film is attached to the top layer to close the entire laminated structure.

[0034] At this point, all materials have been accurately stacked together according to the design requirements to form a complete circuit board substrate stacking structure. However, to make this structure truly stable and reliable, a key operation is still required - pressing. Pressing is carried out under high temperature and high pressure conditions. Uniform pressure and heat are applied by special equipment to make each layer of material tightly combined, especially the resin in the prepreg fully penetrates between each interface and finally solidifies to form irreversible chemical bonds. Pressing parameters such as temperature, pressure and time need to be strictly controlled to ensure the best effect. In addition, target holes need to be drilled before pressing to facilitate precise positioning in subsequent processes.

[0035] Exemplarily, in step S7, a double-sided copper-embedded symmetrical double-sided circuit board is prepared based on the circuit board substrate laminate structure. It should be understood that when all materials, including two pre-treated copper-clad core boards (L1 / L2 and L3 / L4), polyimide films (PI films) and pre-treated copper blocks, have been accurately stacked together according to the design requirements and formed a complete circuit board substrate laminate structure, the next step is the crucial pressing stage. Pressing is carried out under high temperature and high pressure conditions, the purpose is to make each layer of material tightly combined, especially the resin in the prepreg fully penetrates between each interface, and finally solidifies to form an irreversible chemical bond. In order to ensure the best effect, the technician will put the laminated structure into a special hot press and set appropriate temperature, pressure and time parameters. For example, the temperature is usually set between 170°C and 180°C, the pressure is about 2 to 3 MPa, and the duration is 60 to 90 minutes. These parameters need to be fine-tuned according to the specific materials and equipment characteristics used to ensure the pressing quality.

[0036] After the lamination is completed, the circuit board substrate removed from the hot press needs to go through some necessary post-processing steps. The first step is to tear off the PI films on the two outer surfaces, because these films are only used for protection and isolation and are no longer needed after the lamination is completed. If there is excess glue at the interface between the edge of the copper block and the core board, it is necessary to use a double-sided sanding belt to polish it to remove excess resin residue and ensure a smooth surface. In addition, for some applications, it may be necessary to perform additional grinding or polishing on the area around the copper block to improve the appearance quality and contact performance.

[0037] Next, the drilling process begins. Through high-precision equipment such as CNC drilling machines or laser drilling machines, the required through holes and blind holes are drilled at designated locations according to the design drawings. These holes are not only used to install electronic components, but also provide channels for subsequent electroplating and other processing. Strict dimensional control and positioning accuracy must be maintained during the drilling process to avoid short circuits or other faults due to deviations. After drilling is completed, copper deposition is also required, that is, a thin and uniform copper film is deposited on the hole wall to ensure good conductive connection.

[0038] Subsequently, the entire board is electroplated, a step designed to form a thick and uniform layer of copper on the entire surface of the circuit board, thereby enhancing conductivity and corrosion resistance. During the electroplating process, technicians will pay close attention to parameters such as current density, solution composition, and temperature to ensure that the quality of the coating meets the standards. This is followed by pattern transfer and copper-tin plating, which uses an anti-etching agent to cover the parts that do not need to be electroplated, and then uses an electroplating process to thicken the copper layer on the exposed copper surface, and finally plate a layer of tin as a protective coating. The film stripping and etching and tin stripping process removes the anti-etching agent and etches away the excess, leaving the final circuit pattern.

[0039] Among them, the double-sided copper embedded symmetrical structure double-sided circuit board has the following advantages: 1. There is a small gap between the copper block and the FR4 gong vacancy, which is convenient for placing and removing the copper block. At the same time, it can ensure that the resin of the semi-cured sheet is filled on the sides of the copper block, and the semi-cured sheet resin on the bottom is fully in contact, which is conducive to improving the bonding strength of the two materials. 2. The cutting of the copper block is equivalent to the two core boards. The two outer surface steel plates are used as the reference surface. 2-3 semi-cured sheets are used in the middle during pressing. When the copper block is slightly thinner or thicker than the core board, the semi-cured sheet in the middle has enough buffer space to ensure that the surface of the copper block is completely flush with the surface of the first and second core boards. 3. A 0.025-0.05MM PI film is attached to the two outer surfaces, which can ensure that the resin of the semi-cured sheet is filled along the gap between the core board and the copper block during pressing without contaminating the surface copper foil of the first and second core boards. Even if there is, it is very little and can be easily removed by normal sanding. 4. The use of copper core boards will not cause quality problems caused by wrinkles of conventional pressed thin copper foil. 5. The symmetrical structure is conducive to controlling the warping of the board. At the same time, it can ensure that copper can be embedded in the same position on the upper and lower surfaces for current carrying and heat dissipation of different electrical networks, which has fewer design limitations.

[0040] In particular, for double-sided copper embedded symmetrical structure double-sided circuit boards, it is crucial to ensure the consistency of the circuit patterns on both sides, because the high matching of the lines on both sides can ensure the consistency of the current path and the synchronous transmission of signals. If there is a deviation in the patterns on both sides, it may cause impedance mismatch, which in turn affects the signal quality and electrical performance. Specifically, the inconsistency of the circuit pattern may lead to different current paths, resulting in changes in electrical parameters such as resistance, capacitance and inductance. This will affect the operating frequency, signal integrity and power efficiency of the circuit, especially in high-speed digital circuits and high-frequency analog circuits, where any slight changes may cause product performance degradation or functional failure. For high-power applications, good heat dissipation is the key to ensuring stable operation of the equipment. If the circuit design on both sides is asymmetrical, it may affect the uniform distribution of heat, resulting in excessive temperatures in certain areas, which in turn affects the life of electronic components or even causes damage. In addition, the asymmetrical design may also limit the effective heat dissipation path, making the overall heat dissipation effect worse.

[0041] Based on this, in the process of pattern transfer and etching of the first copper clad core board and the second copper clad core board, it is crucial to evaluate the consistency between the transfer pattern of the first copper clad core board after etching and the transfer pattern of the second copper clad core board after etching to determine the pattern transfer quality. Specifically, in the process of pattern transfer quality evaluation, the technical concept of the present application is to collect the transfer pattern image of the first copper clad core board after etching and the transfer pattern image of the second copper clad core board after etching through a camera, and introduce an image processing and analysis algorithm based on artificial intelligence and machine vision at the back end to analyze the transfer pattern images of the first copper clad core board after etching and the second copper clad core board after etching, so as to extract the semantic features in the two transfer pattern images, and perform pattern transfer quality evaluation based on the joint perception contrast feature representation between the semantics of the transfer pattern images of the two copper clad core boards after etching, so as to judge whether the consistency between the transfer pattern of the first copper clad core board after etching and the transfer pattern of the second copper clad core board after etching meets the preset standard. In this way, the pattern transfer quality assessment can be automatically performed based on the semantic joint analysis results of the transfer patterns of the two etched copper clad core boards, so that corresponding measures can be taken in time when it is detected that the quality does not meet the preset standards. This intelligent processing method can help ensure the electrical performance and heat dissipation effect of the final double-sided copper embedded symmetrical structure double-sided circuit board product.

[0042] In one embodiment, Figure 3As shown, the first copper clad core board and the second copper clad core board are subjected to pattern transfer and etching treatment to obtain a first etched copper clad core board and a second etched copper clad core board, including: S21, collecting a transfer pattern image of the first etched copper clad core board and a transfer pattern image of the second etched copper clad core board through a camera; S22, performing image denoising and image enhancement on the transfer pattern image of the first etched copper clad core board and the transfer pattern image of the second etched copper clad core board to obtain a first pre-processed transfer pattern image and a second pre-processed transfer pattern image; S23, respectively performing image denoising and image enhancement on the first pre-processed transfer pattern image and the second pre-processed transfer pattern image. The second preprocessed transfer pattern image is subjected to transfer pattern image feature extraction to obtain first transfer pattern image semantic coding features and second transfer pattern image semantic coding features; S24, the first transfer pattern image semantic coding features and the second transfer pattern image semantic coding features are subjected to feature joint perception based on the semantic information field to obtain first-second transfer pattern image semantic coding contrast features; S25, based on the first-second transfer pattern image semantic coding contrast features, it is determined whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets a preset standard.

[0043] Exemplarily, in step S21, a transfer pattern image of the copper clad core board after the first etching and a transfer pattern image of the copper clad core board after the second etching are collected by a camera. It should be possible to collect the transfer pattern image of the copper clad core board after the first etching and the transfer pattern image of the copper clad core board after the second etching by a camera to ensure the high matching of the circuit patterns on both sides of the double-sided circuit board with a double-sided copper embedded symmetrical structure, which is very important for ensuring the consistency of the current path and the synchronous transmission of signals. If there is a deviation in the patterns on both sides, it may cause impedance mismatch, which in turn affects the signal quality and electrical performance, especially in high-speed digital circuits and high-frequency analog circuits, any slight changes may cause product performance degradation or functional failure. In addition, a good heat dissipation design relies on a symmetrical structure to ensure that heat is evenly distributed and avoid local overheating problems.

[0044] In one embodiment, it is first necessary to ensure that the camera is installed in a fixed and stable position to avoid shooting deviations caused by vibration or other external interference. Use a high-resolution industrial camera with an appropriate lens and light source system to obtain clear, high-contrast images. Calibrate the camera, including focus adjustment, white balance setting, etc., to ensure consistent results for each shot. Place the first etched copper clad core board and the second etched copper clad core board on a dedicated platform with precise positioning devices, such as vacuum adsorption or mechanical clamps, to ensure that each core board remains stationary during shooting.

[0045] Exemplarily, in step S22, the transfer pattern image of the first etched copper clad core board and the transfer pattern image of the second etched copper clad core board are subjected to image denoising and image enhancement to obtain a first pre-processed transfer pattern image and a second pre-processed transfer pattern image. It should be understood that in an actual production environment, due to various factors such as lighting conditions, shooting angles, surface reflections, etc., the collected original images often contain noise and other interferences, which will affect the accuracy of subsequent processing. These unnecessary components can be removed or reduced by image denoising, while image enhancement can highlight important structural information, making circuit lines more clearly visible, thereby providing a more reliable basis for subsequent feature extraction and quality assessment.

[0046] Specifically, in the preparation process of double-sided copper embedded symmetrical structure double-sided circuit boards, the circuit patterns on the two copper-clad core boards need to be highly matched to ensure the consistency of the current path and synchronous signal transmission. If there is a deviation in the patterns on both sides, it may cause impedance mismatch, which in turn affects the signal quality and electrical performance. Therefore, it is necessary to ensure that the image used for evaluation has high resolution, good contrast, and accurate color representation. Image noise reduction and enhancement processing are precisely for this purpose. They help to improve the accuracy of pattern consistency evaluation and ensure the quality of the circuit board.

[0047] In one embodiment, for image noise reduction, the present application selects a denoising algorithm based on wavelet transform. This algorithm can effectively remove random noise while retaining edge details, making the image smoother and cleaner. Next is the image enhancement step, where the histogram equalization method is used, which expands the brightness range and enhances the contrast by adjusting the distribution of image grayscale values, making the originally darker or brighter parts more obvious. In addition, adaptive contrast adjustment technology is also applied to dynamically change the contrast according to the characteristics of the local area, further highlighting small but important structural features such as the center of the pad and the end point of the line. After the above processing, the first pre-processed transfer pattern image and the second pre-processed transfer pattern image are obtained. At this time, the circuit lines in the image are very clear, the background noise is almost completely gone, and each key feature point is easier to identify.

[0048] Exemplarily, in step S23, transfer pattern image features are extracted from the first preprocessed transfer pattern image and the second preprocessed transfer pattern image to obtain the first transfer pattern image semantic coding features and the second transfer pattern image semantic coding features. It should be understood that, considering that the patterns on the circuit board are usually very complex and contain a large amount of circuit detail information. Although the traditional CNN can capture local features well, it has limited effect in processing global circuit semantics and contextual relationships. At the same time, the automated detection system in the electronics manufacturing industry often needs to process a large amount of data in real time, so it has high requirements on the speed and efficiency of the algorithm. Based on this, in the technical solution of the present application, the first preprocessed transfer pattern image and the second preprocessed transfer pattern image are further input into the transfer pattern image feature extractor based on the Mobile-Former model to obtain the first transfer pattern image semantic coding feature map and the second transfer pattern image semantic coding feature map. It should be understood that the Mobile-Former model is a hybrid deep learning model that combines the advantages of the Transformer architecture and a lightweight convolutional neural network (CNN). It aims to address the limitations of traditional CNN in processing long-distance dependencies, while also overcoming the problem of high computational resource consumption of the pure Transformer model, allowing the model to run efficiently in a resource-constrained environment. Therefore, through the processing of the transfer pattern image feature extractor based on the Mobile-Former model, it is possible to further perceive the global contextual local association semantic feature information based on the local features in the first preprocessed transfer pattern image and the second preprocessed transfer pattern image, thereby better understanding and encoding these complex pattern structures and the associations between them, thereby generating a more accurate semantic encoding feature map.

[0049] In one embodiment, transfer pattern image feature extraction is performed on the first preprocessed transfer pattern image and the second preprocessed transfer pattern image to obtain a first transfer pattern image semantic coding feature and a second transfer pattern image semantic coding feature, respectively, including: inputting the first preprocessed transfer pattern image and the second preprocessed transfer pattern image into a transfer pattern image feature extractor based on a Mobile-Former model to obtain a first transfer pattern image semantic coding feature map as the first transfer pattern image semantic coding feature and a second transfer pattern image semantic coding feature map as the second transfer pattern image semantic coding feature.

[0050] Exemplarily, in step S24, the first transfer pattern image semantic coding features and the second transfer pattern image semantic coding features are subjected to feature joint perception based on the semantic information field to obtain first-second transfer pattern image semantic coding contrast features. It should be understood that since the first transfer pattern image semantic coding feature map and the second transfer pattern image semantic coding feature map respectively contain semantic feature information about the transfer pattern image of the first etched copper clad core board and the second etched copper clad core board. In order to be able to interactively analyze and compare the difference features of the semantics of the two transfer pattern images and provide a basis for the subsequent pattern transfer consistency quality assessment of the two, in the technical solution of the present application, the first transfer pattern image semantic coding features and the second transfer pattern image semantic coding features are further subjected to feature joint perception based on the semantic information field to obtain first-second transfer pattern image semantic coding contrast features. In particular, through the joint perception processing of features based on the semantic information field, the semantic information field can be used as a guide to achieve interaction and modulation between features, thereby generating a richer and more semantically interpretable first-second transfer pattern image semantic coding contrast feature representation, so that the subtle differences between the patterns on both sides of the circuit board can be captured more accurately. This helps to improve the accuracy of consistency assessment and ensure the quality of the circuit board.

[0051] In one embodiment, Figure 4 As shown, the first transfer pattern image semantic coding feature and the second transfer pattern image semantic coding feature are subjected to feature joint perception based on the semantic information field to obtain a first-second transfer pattern image semantic coding contrast feature, including: S241, feature-connecting the second transfer pattern image semantic coding feature map and the first transfer pattern image semantic coding feature map and then inputting the map into a semantic information field predictor based on gated convolution to obtain a transfer pattern image semantic information field; S242, based on the transfer pattern image semantic information field, performing feature joint perception on the second transfer pattern image semantic coding feature map and the first transfer pattern image semantic coding feature map to obtain a first-second transfer pattern image semantic coding contrast feature map as the first-second transfer pattern image semantic coding contrast feature.

[0052] Exemplarily, in step S241, the second transfer pattern image semantic encoding feature map and the first transfer pattern image semantic encoding feature map are feature-connected and then input into a semantic information field predictor based on gated convolution to obtain a transfer pattern image semantic information field. Specifically, the process can be expressed as follows:

[0053] in, is the second transfer pattern image semantic encoding feature map, is the semantic encoding feature map of the first transfer pattern image, represents the feature connection operation, The convolution kernel is The convolutional layer, For point convolution processing, To transfer the semantic information field of pattern image.

[0054] It should be understood that feature connection of the second transfer pattern image semantic encoding feature map and the first transfer pattern image semantic encoding feature map means combining them into a new multi-channel feature representation, which integrates information from two directions. This is done to allow the model to consider the contents of the two images at the same time and learn the correspondence between them. Subsequently, this combined feature is fed into a semantic information field predictor based on gated convolution. Gated convolution is a special convolution operation that allows the network to dynamically adjust its receptive field size according to the input data, which means that it can capture long-distance dependencies more flexibly, especially when facing complex circuit patterns. In addition, the gating mechanism can help the model focus on areas that are really important for the task, suppress irrelevant parts, and improve computational efficiency. The task of the semantic information field predictor is to use the above input to generate the so-called "transfer pattern image semantic information field". Simply put, this is a global map that describes the semantic similarity and difference between two transfer patterns. In this map, each position represents the degree of matching of the semantic features of the two patterns in a specific local area. Ideally, if the patterns on the two copper-clad core boards are exactly the same, a highly consistent distribution pattern should be presented throughout the semantic information field; conversely, if there is any deviation or asymmetry, obvious outliers will be displayed at the corresponding positions. This method based on the semantic information field has significant advantages over traditional pixel-level comparison. Because traditional methods can often only stay at the comparison of surface morphology, they are easily affected by factors such as noise and illumination changes, but are powerless for deep functional differences. By constructing a semantic information field, the present application can not only more accurately identify where changes have occurred, but also understand the meaning behind these changes. For example, in an actual production environment, even if two patterns look very similar, if they have different connection methods or wiring strategies at key nodes, this may lead to a huge gap in the performance of the final product.

[0055] In one embodiment, in step S242, based on the transfer pattern image semantic information field, the second transfer pattern image semantic coding feature map and the first transfer pattern image semantic coding feature map are subjected to feature joint perception to obtain a first-second transfer pattern image semantic coding contrast feature map as the first-second transfer pattern image semantic coding contrast feature, including: mapping the second transfer pattern image semantic coding feature map to the transfer pattern image semantic information field to obtain a field-modulated second transfer pattern image semantic coding feature map. Specifically, the process can be expressed by a formula as follows:

[0056] in, For point-by-position multiplication, It is the semantic coding feature map of the field modulated second transfer pattern image.

[0057] The first transfer pattern image semantic coding feature map and the field modulated second transfer pattern image semantic coding feature map are input into a feature joint perception module based on a multiple attention structure to obtain the first-second transfer pattern image semantic coding contrast feature map. Specifically, the process can be expressed as follows:

[0058]

[0059]

[0060] in, For point-by-point convolution processing, is the global mean pooling operation, For channel-by-channel convolution processing, is the batch normalization layer, is the Sigmoid function, For the second transfer pattern image semantic attention optimization expression feature map, For attention optimization, the first transfer pattern image semantic attention optimization expression feature map, For positional addition, It is the semantic coding contrast feature map of the first and second transfer pattern images.

[0061] It should be understood that in the process of mapping the semantic coding feature map of the second transfer pattern image to field modulation, the semantic coding features of the second transfer pattern image are actually adjusted or enhanced using the previously generated semantic information field as a guide. This process can be regarded as adding a layer of weight or emphasis mark to the original semantic coding feature map, so that those areas identified as important in the semantic information field are more prominent, while non-critical parts are appropriately weakened. Such an operation improves the sensitivity of the model to specific objects or areas, enabling it to better adapt to various complex situations in actual production. For example, even slight changes in certain key nodes such as power lines and signal lines may affect the function of the entire circuit, while in other non-critical areas, even if there are some differences, the overall performance will not be significantly affected. The new feature map obtained after field modulation, that is, the semantic coding feature map of the second transfer pattern image modulated by field modulation, is an optimized expression of the semantic coding feature map of the original second transfer pattern image, which not only retains the original local detail information, but also enhances the focus on key areas through the adjustment of the semantic information field. This step provides a more reliable basis for subsequent quality assessment. Finally, the optimized semantic coding feature map of the second transfer pattern image modulated by field modulation is compared with the semantic coding feature map of the first transfer pattern image. Figure 1 The two images are input into the feature joint perception module based on the multi-attention structure. The role of this module is to further analyze the correlation and contrast characteristics between the two. Through the multi-attention mechanism, the model can focus on the areas and features that are most critical for determining pattern consistency and electrical performance. The multi-attention structure allows the model to consider multiple different levels of information at the same time, and to establish connections between these information, thereby more accurately identifying the subtle differences between the two transferred pattern images.

[0062] In summary, through the joint perception processing of features based on the semantic information field, it is possible to construct a semantic information field and modulate the semantic features of the second transfer pattern image accordingly, ensuring that the feature expression not only contains rich detail information, but also is consistent with the structure of the semantic features of the first transfer pattern image. Specifically, in the actual process of pattern transfer quality assessment, there may be some asymmetry or changes in the pattern on the circuit board (such as line width differences, shape distortions, etc.). In this case, semantic-level feature modulation helps to improve the model's sensitivity to specific objects or areas, so as to better adapt to these complex situations. In this way, it can more effectively help identify the feature differences between the two transfer pattern images to generate the first-second transfer pattern image semantic coding comparison features, which can be used to subsequently determine whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets the preset standard, thereby ensuring the consistency of the double-sided circuit board pattern.

[0063] Exemplarily, in step S25, based on the semantic coding contrast features of the first-second transfer pattern images, it is determined whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets the preset standard. In one embodiment, based on the semantic coding contrast features of the first-second transfer pattern images, it is determined whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets the preset standard, including: inputting the first-second transfer pattern image semantic coding contrast feature map into a pattern transfer quality evaluator based on a classifier to obtain an evaluation result, and the evaluation result is used to indicate whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets the preset standard. That is, the classification process is performed using the joint perception semantic contrast representation between the transfer pattern image semantic features of the first etched copper clad core board and the transfer pattern image semantic features of the second etched copper clad core board, so as to perform pattern transfer quality evaluation, thereby judging whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets the preset standard. In this way, the pattern transfer quality assessment can be automatically performed based on the semantic joint analysis results of the transfer patterns of the two etched copper clad core boards, so that corresponding measures can be taken in time when it is detected that the quality does not meet the preset standards. This intelligent processing method can help ensure the electrical performance and heat dissipation effect of the final double-sided copper embedded symmetrical structure double-sided circuit board product.

[0064] In summary, according to the embodiment of the present application, a double-sided copper-embedded symmetrical structure double-sided circuit board and its preparation method are explained, which can ensure the accuracy of the copper-embedded area through the gong plate treatment, enhance the bonding force between copper and the substrate through the browning treatment, and effectively enhance the stability and mechanical strength of the entire circuit board structure by laminating treatment with polyimide film. At the same time, it also provides a buffer for the difference in thermal expansion coefficients between different materials, preventing delamination or fracture problems caused by temperature changes.

[0065] Specifically, a double-sided copper-embedded symmetrical structure double-sided circuit board is also provided, and the double-sided copper-embedded symmetrical structure double-sided circuit board is manufactured by the aforementioned preparation method of the double-sided copper-embedded symmetrical structure double-sided circuit board.

[0066] The basic principle of the present invention is described above in conjunction with specific embodiments. However, it should be pointed out that the advantages, strengths, effects, etc. mentioned in the present invention are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. must be possessed by each embodiment of the present invention. In addition, the specific details of the above embodiments are only for the purpose of illustration and facilitation of understanding, rather than limitation, and the above details do not limit the present invention to being implemented by adopting the above specific details.

[0067] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, please refer to the relevant description of other embodiments. In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the module division is only a logical function division, and there may be other division methods in actual implementation. The modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment.

[0068] In addition, each functional module in each embodiment of the present invention may be integrated into one processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0069] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference to a figure in a claim should not be considered as limiting the claim to which it relates.

[0070] In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units stated in the device claim can also be implemented by one unit through software or hardware.

[0071] Finally, it should be noted that the above description has been given for the purpose of illustration and description. In addition, the above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure, characterized in that: include: Providing a first copper clad core board and a second copper clad core board; Performing pattern transfer and etching treatment on the first copper clad core board and the second copper clad core board to obtain a first etched copper clad core board and a second etched copper clad core board; Performing lamination treatment on the copper embedded areas of the first etched copper clad core board and the second etched copper clad core board to obtain a first lamination copper clad core board and a second lamination copper clad core board; Provide copper blocks; The first copper clad core board after the gong plate, the second copper clad core board after the gong plate and the copper block are subjected to browning treatment and drying to obtain a first pre-treated copper clad core board, a second pre-treated copper clad core board and a pre-treated copper block; Based on the polyimide film, the first pretreated copper clad core board, the second pretreated copper clad core board and the pretreated copper block are laminated to obtain a circuit board substrate laminated structure; Based on the circuit board substrate laminated structure, a double-sided circuit board with a double-sided copper embedded symmetrical structure is prepared.

2. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 1, characterized in that: In performing pattern transfer and etching on the first copper clad core board and the second copper clad core board to obtain a first etched copper clad core board and a second etched copper clad core board, the size of the gong plate is 0.05 mm-0.075 mm larger than the copper block.

3. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 2, characterized in that: Based on the polyimide film, the first pretreated copper clad core board, the second pretreated copper clad core board and the pretreated copper block are laminated to obtain a circuit board substrate laminate structure, including: Attaching a first polyimide film to the copper foil of the copper clad core board after the first pretreatment; Placing the pretreated copper block on the first polyimide film, wherein the pretreated copper block corresponds to the copper embedded area of ​​the first pretreated copper clad core board; Based on thickness requirements, placing a predetermined number of prepregs on the pretreated copper block; Placing the second pretreated copper clad core board on the prepreg; Placing the pretreated copper block on the second pretreated copper clad core board; placing a second polyimide film on the pretreated copper block to obtain a laminated structure; The laminated structure is pressed to obtain the circuit board substrate laminated structure.

4. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 3, characterized in that: The thickness of the first polyimide film and the second polyimide film is 0.025 mm-0.05 mm.

5. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 4, characterized in that: The first copper clad core board and the second copper clad core board are subjected to pattern transfer and etching treatment to obtain a first etched copper clad core board and a second etched copper clad core board, comprising: Collecting a transfer pattern image of the first etched copper clad core board and a transfer pattern image of the second etched copper clad core board through a camera; Performing image noise reduction and image enhancement on the first etched copper clad core board transfer pattern image and the second etched copper clad core board transfer pattern image to obtain a first pre-processed transfer pattern image and a second pre-processed transfer pattern image; Performing transfer pattern image feature extraction on the first preprocessed transfer pattern image and the second preprocessed transfer pattern image to obtain a first transfer pattern image semantic coding feature and a second transfer pattern image semantic coding feature; Performing feature joint perception based on the semantic information field on the first transfer pattern image semantic coding feature and the second transfer pattern image semantic coding feature to obtain a first-second transfer pattern image semantic coding contrast feature; Based on the semantic coding comparison features of the first-second transfer pattern images, it is determined whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets a preset standard.

6. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 5, characterized in that: Transfer pattern image feature extraction is performed on the first preprocessed transfer pattern image and the second preprocessed transfer pattern image respectively to obtain a first transfer pattern image semantic coding feature and a second transfer pattern image semantic coding feature, including: inputting the first preprocessed transfer pattern image and the second preprocessed transfer pattern image respectively into a transfer pattern image feature extractor based on a Mobile-Former model to obtain a first transfer pattern image semantic coding feature map as the first transfer pattern image semantic coding feature and a second transfer pattern image semantic coding feature map as the second transfer pattern image semantic coding feature.

7. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 6, characterized in that: Performing feature joint perception based on the semantic information field on the first transfer pattern image semantic coding feature and the second transfer pattern image semantic coding feature to obtain first-second transfer pattern image semantic coding contrast feature, including: The second transfer pattern image semantic encoding feature map and the first transfer pattern image semantic encoding feature map are feature-connected and then input into a semantic information field predictor based on gated convolution to obtain a transfer pattern image semantic information field; Based on the transfer pattern image semantic information field, feature joint perception is performed on the second transfer pattern image semantic coding feature map and the first transfer pattern image semantic coding feature map to obtain a first-second transfer pattern image semantic coding contrast feature map as the first-second transfer pattern image semantic coding contrast feature.

8. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 7, characterized in that: Based on the transfer pattern image semantic information field, performing feature joint perception on the second transfer pattern image semantic coding feature map and the first transfer pattern image semantic coding feature map to obtain a first-second transfer pattern image semantic coding contrast feature map as the first-second transfer pattern image semantic coding contrast feature, including: Mapping the second transfer pattern image semantic coding feature map to the transfer pattern image semantic information field to obtain a field-domain modulated second transfer pattern image semantic coding feature map; The first transfer pattern image semantic coding feature map and the field modulated second transfer pattern image semantic coding feature map are input into a feature joint perception module based on a multiple attention structure to obtain the first-second transfer pattern image semantic coding contrast feature map.

9. The method for preparing a double-sided circuit board with a double-sided copper embedded symmetrical structure according to claim 8, characterized in that: Based on the semantic coding contrast features of the first-second transfer pattern images, determining whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets the preset standard, including: inputting the semantic coding contrast feature map of the first-second transfer pattern images into a classifier-based pattern transfer quality evaluator to obtain an evaluation result, and the evaluation result is used to indicate whether the consistency between the transfer pattern of the first etched copper clad core board and the transfer pattern of the second etched copper clad core board meets the preset standard.

10. A double-sided circuit board with a double-sided copper embedded symmetrical structure, characterized in that: The double-sided circuit board with a symmetrical structure of double-sided copper embedding is manufactured by the method for manufacturing a double-sided circuit board with a symmetrical structure of double-sided copper embedding as claimed in any one of claims 1 to 9.

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