A method for manufacturing PCBs that solves the problem of large-hole dry film defects.

Abstract

This invention discloses a PCB manufacturing method for solving the problem of large-hole dry film defects, including basic process processing, first film lamination, first exposure, first development, second film lamination, second exposure, second development, and PCB forming steps. This invention, through a process design of two film laminations, two exposures, and two developments, forms a double-layer dry film structure at large PTH holes with a diameter ≥6mm, significantly improving the sealing ability of large holes and the dry film's resistance to chemical impact. It effectively solves the problem of copper-free large holes caused by dry film defects, greatly reducing the PCB scrap rate and improving product yield and processing quality.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board manufacturing technology, specifically to a method for manufacturing PCBs that solves the problem of large-hole dry film breakage. Background Technology

[0002] As electronic products become increasingly integrated and precise, PCB circuit designs are becoming more and more intricate. To meet the precision requirements of these fine lines, the industry commonly uses high-resolution dry film for pattern transfer. The core characteristic of high-resolution dry film is its thinness (<30µm), but this characteristic also significantly reduces its ability to seal large holes (PTH holes with a diameter ≥6mm), making it highly susceptible to dry film breakage during processing.

[0003] In the PCB outer layer pattern etching process, if the dry film at large holes is damaged, the etching solution will seep into the holes, etching the copper layer inside and ultimately resulting in a defect where the holes have no copper, severely affecting the electrical conductivity of the PCB. This defect leads to a higher scrap rate of finished PCBs, increased processing costs, and difficulty in meeting the assembly and usage requirements of downstream electronic components, becoming a key issue restricting the large-scale, high-quality production of PCBs with fine-line patterns.

[0004] The current PCB outer layer pattern processing flow is as follows: material cutting, inner layer pattern transfer, etching, lamination, drilling, copper plating, electroplating, outer layer pattern pretreatment, film lamination, exposure, development, etching, AOI, solder mask, text, surface coating, molding, electrical testing, FQC, FQA, and packaging. However, this process only uses a single film lamination, exposure, and development step, which cannot solve the problem of dry film breakage caused by insufficient large-hole sealing capability for high-resolution thin dry films. Currently, there is no effective targeted solution. Summary of the Invention

[0005] To overcome the problem of dry film breakage and copper-free holes in large holes during the processing of fine-line PCBs with high-resolution thin dry film in existing technologies, this invention provides a PCB manufacturing method that solves the problem of dry film breakage in large holes. Through a process design of two film laminations, two exposures, and two developments, a double-layer dry film structure is formed at the large holes, which greatly improves the sealing capability of large holes, effectively solves the problem of copper-free holes in large holes caused by dry film breakage, reduces PCB scrap rate, and improves product yield and processing quality.

[0006] The technical solution of this invention is as follows:

[0007] A method for manufacturing a PCB board to solve the problem of large-hole dry film defects includes:

[0008] Basic manufacturing process: sequentially perform material cutting, inner layer pattern transfer, etching, lamination, drilling, copper plating, electroplating, and outer layer pattern pretreatment to complete the basic circuit and hole structure of the PCB board.

[0009] One-time film application: Dry film is applied to the outer copper surface of the pre-treated PCB board;

[0010] Single exposure: Using the outer layer pattern exposure data of the PCB board, the PCB board after dry film is applied is exposed to achieve the transfer of the overall circuit pattern;

[0011] Single development: Using development process parameters compatible with the dry film type, the PCB board after one exposure is developed to expose the copper surface area to be etched without dry film protection.

[0012] Secondary film application: Dry film is applied again to the surface of the PCB board after the first development, and the dry film applied in the second application is the same type as the dry film used in the first application.

[0013] Secondary exposure: The PCB board after secondary film application is exposed using large hole exposure data. Only PTH large hole patterns with a hole diameter ≥ 6mm are retained in the large hole exposure data.

[0014] Secondary development: Using development process parameters compatible with the dry film type, the PCB board after secondary exposure is developed to form a double-layer dry film structure at the PTH large holes with a diameter ≥6mm.

[0015] PCB board forming: The PCB board after secondary development is formed.

[0016] As a preferred embodiment of the present invention, the dry film is a high-resolution dry film with a thickness of <30µm.

[0017] As a preferred embodiment of the present invention, in the large-aperture exposure data, the aperture ring size of the PTH large-aperture pattern with an aperture diameter ≥ 6 mm is the same as the corresponding aperture ring size in the outer layer pattern exposure data.

[0018] In a preferred embodiment of the present invention, the process parameters for the second film application are consistent with those for the first film application in the second film application step.

[0019] In a preferred embodiment of the present invention, the process parameters for the second development step are consistent with those for the first development step.

[0020] As a preferred embodiment of the present invention, the basic manufacturing process includes the following sub-steps:

[0021] Material preparation: Select the copper-clad laminate substrate corresponding to the design plan requirements and bake it; then cut it into substrates of appropriate size according to the processing requirements, round the corners of the substrates, and polish the edges of the substrates.

[0022] Inner layer pattern transfer: The inner layers of the substrate are pre-processed, and the designed circuit pattern is transferred to the copper foil surface of the substrate using an LDI exposure machine.

[0023] Etching: The dry film in the unexposed areas is removed by developing, exposing the bare copper. The copper foil not protected by the dry film is removed by chemical etching. Then the resist layer is removed by stripping to obtain the desired inner layer circuit pattern.

[0024] Lamination: Prepreg is attached to the upper and lower surfaces of the formed inner layer circuit pattern, and copper plates are attached to the upper and lower surfaces of the prepreg, and then lamination is performed by a press;

[0025] Drilling: The drilling process creates a connection between the inner core board and the outer core board;

[0026] Plating: Plating copper foil and electroplating processes increase the thickness of the outer copper foil layer and form a copper layer inside the holes.

[0027] Outer layer pattern preprocessing: Preprocess the outer copper surface of the PCB board to remove surface contaminants and roughen the copper surface.

[0028] As a preferred embodiment of the present invention, the pretreatment of the inner layer of the substrate includes: removing contaminants from the surface of the copper foil layer of the substrate by alkaline milling, then roughening the surface of the copper foil layer by using an ultra-roughening solution, drying and heating to 75°C, and then performing dry film bonding.

[0029] As a preferred embodiment of the present invention, in the outer layer pattern preprocessing, a volcanic ash grinding line or a medium roughening preprocessing line is used to preprocess the outer copper surface of the PCB board.

[0030] As a preferred embodiment of the present invention, in the PCB board forming step, the PCB board after secondary development is sequentially etched, inspected by AOI, solder mask applied, text applied, surface coated, formed, electrical tested, FQC, FQA, and packaged to complete the overall production of the PCB board.

[0031] As a preferred embodiment of the present invention, the outer layer graphic exposure data is an outer layer GTL / GBL graphic exposure data.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. This invention uses a process design of two film application, two exposures, and two developments to form a double-layer dry film structure at PTH large holes with a diameter ≥6mm. Compared with traditional single-layer dry film, it significantly improves the sealing ability of large holes and the dry film's resistance to chemical impact, effectively solving the defects of no copper in holes caused by large hole dry film breakage and etching chemical penetration during high-resolution thin dry film processing.

[0034] 2. In this invention, only the large hole pattern is retained during the second exposure, while all other lines and small hole patterns are deleted. This ensures that the remaining areas except for the large holes still maintain a single-layer dry film structure, without affecting the etching accuracy of the fine lines, thus balancing the requirements for sealing large holes and the processing requirements for fine lines.

[0035] 3. In this invention, the secondary film application does not require a pre-processing line. The film is applied directly to the surface of the board after the first development, avoiding damage to the already formed dry film pattern caused by the pre-processing process and ensuring the integrity of the circuit pattern.

[0036] 4. This invention only adds one film application, one exposure, and one development step to the existing PCB board processing flow. The process changes are minor, no new large-scale processing equipment is required, it is easy to achieve large-scale application on existing production lines, and the modification cost is low.

[0037] 5. This invention effectively solves the defect of large holes without copper, significantly reduces the scrap rate of PCB boards, improves product yield and processing quality, and at the same time reduces production and processing costs, meeting the assembly and use requirements of downstream electronic components. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 these drawings without creative effort.

[0039] Figure 1 This is a flowchart of a PCB board manufacturing method for solving the problem of large-hole dry film breakage in one embodiment of the present invention;

[0040] Figure 2 This is a flowchart illustrating the basic manufacturing process steps in one embodiment of the present invention.

[0041] Figure 3 This is a flowchart illustrating the PCB board forming steps in one embodiment of the present invention. Detailed Implementation

[0042] To make the technical problems, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. It is also stated that the embodiments described below are for illustrative purposes only and are not intended to limit the invention.

[0043] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification and claims of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0044] Please see Figure 1 This embodiment provides a PCB manufacturing method for solving the problem of large-hole dry film breakage, including:

[0045] S1. Basic Processing: Following standard PCB manufacturing processes, the following steps are performed sequentially: material preparation, inner layer pattern transfer, etching, lamination, drilling, copper plating, electroplating, and outer layer pattern pretreatment. Specifically, the drilling process creates PTH large holes (≥6mm in diameter) and other small holes. The copper plating and electroplating processes form a uniform copper layer inside the holes and on the outer copper surface, completing the basic circuitry and hole structure of the PCB.

[0046] S2, One-time film application: A dry film is applied to the outer copper surface of the pre-treated PCB board. This dry film is a high-resolution dry film with a thickness of <30um, which is suitable for the processing precision requirements of fine lines. The film application temperature, speed and other parameters are controlled according to the conventional process.

[0047] S3, Single Exposure: Using the complete GTL / GBL graphic exposure data of the outer layer of the PCB board, the PCB board after dry film is applied is exposed by an exposure machine to achieve the transfer of the overall circuit pattern. The exposure energy and time are set according to the conventional process.

[0048] S4. First Development: Using development process parameters compatible with the dry film type, the PCB board after one exposure is developed to remove the dry film in the unexposed areas, exposing the copper surface area to be etched without dry film protection.

[0049] S5. Secondary film application: Dry film is applied again directly to the surface of the PCB board after the first development. The dry film used for the secondary application is the same as the dry film used for the first application. The board does not pass through the pre-processing line during the film application process to avoid damaging the already formed dry film pattern. The film application parameters for the secondary application are the same as those for the first application.

[0050] S6. Secondary Exposure: The PCB board after secondary film lamination is exposed using large-hole exposure data separately prepared by the engineering department. This data retains only PTH large-hole patterns with a diameter ≥6mm on the PCB board. The ring size of these ≥6mm PTH large-hole patterns is the same as the corresponding ring size in the GTL / GBL pattern exposure data. All other lines and small-hole patterns are deleted. Only the secondary dry film in the large-hole area is exposed and cured. This secondary exposure step retains only the large-hole patterns, deleting all other lines and small-hole patterns. This ensures that the areas other than the large holes maintain a single-layer dry film structure, without affecting the etching accuracy of fine lines, thus balancing the requirements for large-hole sealing and the processing requirements of fine lines.

[0051] S7. Secondary Development: Using development process parameters compatible with the dry film type, the PCB board after secondary exposure is developed to remove the secondary dry film outside the PTH large hole area with a aperture ≥6mm, so that a double-layer dry film structure is formed at the PTH large hole with an aperture ≥6mm, while the remaining circuit and small hole areas retain a single-layer dry film structure.

[0052] S8. PCB Board Forming: The PCB board after secondary development undergoes forming processing, including etching, AOI inspection, solder mask application, texting, surface coating, forming, electrical testing, FQC, FQA, and packaging, completing the overall PCB board manufacturing. During the etching process, the double-layer dry film structure at PTH large holes with a diameter ≥6mm effectively prevents etching solution from seeping in, avoiding etching of the copper layer inside the hole. The single-layer dry film in other areas provides normal circuit etching protection.

[0053] This invention provides a PCB manufacturing method for solving the problem of large-hole dry film defects. Through a process design involving two film laminations, two exposures, and two developments, a double-layer dry film structure is formed at PTH large holes with a diameter ≥6mm. Compared to traditional single-layer dry films, this significantly improves the sealing capability of large holes and the dry film's resistance to chemical impact. It effectively solves the problems of large-hole dry film defects and copper-free defects caused by etching chemical penetration during high-resolution thin dry film processing. During the second exposure, only the large-hole pattern is retained, while all other circuitry and small-hole patterns are deleted, ensuring that the remaining areas except for the large holes maintain a single-layer dry film structure without affecting the overall circuitry. It achieves high etching precision for fine lines while balancing the requirements for sealing large holes with the processing requirements for fine lines. The secondary film application eliminates the need for a pre-processing line, applying the film directly to the surface of the board after the first development step. This avoids damage to the already formed dry film pattern caused by the pre-processing steps, ensuring the integrity of the circuit pattern. It only requires adding one film application, one exposure, and one development step to the existing PCB manufacturing process, resulting in minimal process changes. No new large-scale processing equipment is needed, making it easy to scale up existing production lines with low modification costs. It effectively solves the defect of copper-free large holes, significantly reducing PCB scrap rates, improving product yield and processing quality, while simultaneously lowering production costs and meeting the assembly and usage requirements of downstream electronic components.

[0054] Please see Figure 2 In some embodiments, the basic manufacturing process includes the following sub-steps:

[0055] S11. Material Cutting: Select copper-clad laminate substrates that meet the design specifications. First, bake the substrate to remove internal moisture and release internal stress, ensuring the dimensional stability and structural reliability of the substrate in subsequent processing. Then, cut the substrate into substrates of the preset specifications according to the processing drawings. At the same time, round the corners and polish the edges of the substrates to form smooth edges and corners, avoiding scratches between the boards during the process that could cause appearance and structural defects.

[0056] S12. Inner Layer Pattern Transfer: The inner layer copper foil of the substrate undergoes pretreatment. First, an alkaline milling process is used to remove oil, fingerprints, and various impurities from the copper foil surface. Then, an ultra-roughening solution is used to roughen the copper foil surface, increasing the contact area between the dry film and the copper foil surface and improving the adhesion between the dry film and the copper foil. After drying, the substrate is heated to 75°C for dry film bonding to ensure a tight bond between the dry film and the copper foil surface, reducing problems such as air bubbles and gaps under the film. Subsequently, an LDI exposure machine is used to accurately transfer the designed inner layer circuit pattern to the copper foil surface. Utilizing the high precision and high repeatability of the LDI exposure machine, the clarity and dimensional accuracy of the inner layer circuit pattern are ensured, laying the foundation for fine circuit processing.

[0057] S13, Etching: The exposed substrate is developed to completely remove the dry film in the unexposed areas, exposing the bare copper areas to be etched; a chemical etching process is used to etch away the bare copper not protected by the dry film, and then the resist dry film on the substrate surface is peeled off through a stripping process to obtain the inner layer circuit pattern that meets the design requirements; the dry film after exposure and curing has etching resistance and can effectively protect the copper foil in the preset circuit area from being etched, so as to achieve precise forming of the circuit pattern.

[0058] S14. Lamination: First, the formed inner layer circuit board is browned to form a uniform brown layer on the copper foil surface, which enhances the bonding force between the copper surface and the resin layer. Then, a prepreg is attached to the upper and lower surfaces of the inner layer circuit pattern, and a copper plate is attached to the outside of the prepreg. The board is then laminated under high temperature and high pressure to tightly bond the substrates of each layer of the multilayer board into one, ensuring the structural strength and interlayer bonding reliability of the multilayer PCB board.

[0059] S15. Drilling: According to the circuit connection design requirements of the PCB board, CNC drilling technology is used to process metallized holes on the laminated substrate to realize the physical connection between the inner core board and the outer copper foil, providing a basis for the subsequent copper plating and electroplating processes to achieve interlayer electrical conduction and meet the signal transmission and current conduction requirements of complex circuits.

[0060] S16, Copper Plating and Electroplating: First, a uniform chemical copper layer is deposited on the hole wall and the outer copper surface of the substrate through a chemical copper plating process, making the non-metallic hole wall conductive; then, an electroplating thickening treatment is performed to increase the copper thickness of the outer copper foil to the design requirements, while forming a uniform electroplated copper layer inside the hole, ensuring the conductivity and current carrying capacity of the outer copper surface of the PCB board and inside the hole, meeting the electrical requirements of subsequent circuit operation.

[0061] S17. Outer Layer Pattern Pretreatment: The outer copper surface of the PCB board is treated using a volcanic ash grinding line or a medium roughening pretreatment line. Through physical grinding or chemical roughening, the oxide layer, dirt and adhesive residue on the copper surface are removed. At the same time, the copper surface is roughened to improve the adhesion between the outer dry film and the copper surface, providing a good substrate surface condition for subsequent film lamination processes.

[0062] This embodiment achieves precise forming of inner layer circuits, tight bonding of multilayer boards, and reliable interlayer connectivity through a standardized and refined process flow including material preparation, inner layer pattern transfer, etching, lamination, drilling, copper plating, electroplating, and outer layer pattern pretreatment. This ensures the conductivity, structural stability, and dimensional accuracy of the inner and outer copper surfaces of the PCB board. Simultaneously, through process control at each stage, a substrate with a good surface condition and stable circuit structure is provided for the subsequent core processes of lamination, exposure, and development. This effectively guarantees the forming effect of the subsequent large-hole double-layer dry film structure and avoids the impact of defects in the basic process on the implementation of subsequent core processes, thus controlling the processing quality of the PCB board from the source.

[0063] Please see Figure 3 In some embodiments, the PCB board forming step includes the following sub-steps:

[0064] S81. Etching: The PCB board after secondary development is immersed in the etching solution to chemically etch the copper areas without dry film protection. Among them, the double-layer dry film structure at the PTH large holes with a diameter ≥6mm can effectively prevent the etching solution from seeping into the hole and avoid the copper in the hole being etched. The single-layer dry film of the other lines and small hole areas can normally achieve etching protection, ensuring the etching accuracy and dimensional consistency of fine lines.

[0065] S82, AOI Inspection: Automated optical inspection equipment is used to inspect the appearance and circuitry of the etched PCB board, identifying defects such as short circuits, open circuits, incomplete etching, and dry film residue, thereby enabling the early screening of unqualified boards and controlling process quality.

[0066] S83. Solder resist: Solder resist ink is coated on the surface of the PCB board. After exposure and development, a solder resist layer is formed to protect the lines in non-soldering areas, improve the corrosion resistance and insulation of the PCB board, and avoid the risk of short circuits between lines.

[0067] S84. Text: Silkscreen text information, including component reference numbers, specifications, brand logos, etc., at designated locations on the PCB board to facilitate subsequent component assembly, testing, and maintenance.

[0068] S85. Surface Coating: Perform surface treatment on the soldering area of ​​the PCB board according to design requirements. Processes such as chemical nickel gold, tin spraying, and organic solder mask can be used to improve the solderability of the soldering area, reduce the probability of cold solder joints and false solder joints during subsequent component soldering, and ensure the mechanical strength and electrical conductivity of the solder.

[0069] S86. Molding: The PCB board is processed to the final shape and size required by the design by CNC milling or punching. At the same time, the corners of the board are rounded and the edges are polished to avoid scratches caused by sharp corners and to adapt to the assembly size requirements of actual applications.

[0070] S87. Electrical Testing: Using electrical testing fixtures, the PCB board is tested for electrical performance such as continuity, insulation, and impedance to confirm the conductivity and insulation reliability of the circuitry and to eliminate boards that fail to meet electrical performance standards.

[0071] S88, FQC: Perform final quality inspection on PCB boards, including full appearance inspection, dimensional re-measurement, surface coating quality inspection, etc., to ensure that the boards are free from appearance defects, dimensional deviations and process residues, and meet product delivery standards.

[0072] S89, FQA: Conduct quality audits on boards that have passed FQC inspection, and verify the consistency and stability of product quality through sampling inspection to ensure that the entire batch of products meets design and usage requirements.

[0073] S810 Packaging: The PCB boards that have passed FQA review will be packaged in an anti-static and anti-impact manner. Protective measures will be taken in accordance with transportation and storage requirements to prevent the boards from being scratched, contaminated or damaged by static electricity during transportation and storage, and to ensure the products are delivered to the customer in good condition.

[0074] This embodiment achieves final PCB board processing and end-to-end quality control through a standardized process flow including etching, AOI inspection, solder mask application, texturing, surface coating, molding, electrical testing, FQC, FQA, and packaging. The etching process achieves precise circuit formation, and the double-layer dry film protection fundamentally solves the defect of large holes lacking copper. Multiple inspection and review processes ensure quality control at every stage, significantly reducing the scrap rate. Simultaneously, surface coating and solder mask processes improve the PCB board's corrosion resistance, solderability, and other performance characteristics. The final delivered product fully meets the requirements of downstream electronic component assembly and practical applications, providing a reliable PCB carrier for the stability of subsequent complete products.

[0075] It should be noted that the process of the present invention is not limited to the parameters of the above embodiments. The process parameters of film application, exposure and development can be adjusted according to the actual PCB board specifications and dry film model. As long as the core process of two film applications, two exposures (the second exposure only retains the large hole pattern) and two developments is adopted to form a double-layer dry film structure at the large holes, it falls within the protection scope of the present invention.

[0076] Furthermore, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0077] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

[0078] The present invention has been described above with reference to the accompanying drawings. Obviously, the implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for manufacturing a PCB board to solve the problem of large-hole dry film breakage, characterized in that, include: Basic manufacturing process: sequentially perform material cutting, inner layer pattern transfer, etching, lamination, drilling, copper plating, electroplating, and outer layer pattern pretreatment to complete the basic circuit and hole structure of the PCB board. One-time film application: Dry film is applied to the outer copper surface of the pre-treated PCB board; Single exposure: The PCB board with the outer layer pattern exposure data is exposed to the PCB board after the dry film is applied; Single development: The PCB board after a single exposure is developed using development process parameters that are compatible with the dry film type. Secondary film application: Dry film is applied again to the surface of the PCB board after the first development, and the dry film applied in the second application is the same type as the dry film used in the first application. Secondary exposure: The PCB board after secondary film application is exposed using large hole exposure data. Only PTH large hole patterns with a hole diameter ≥ 6mm are retained in the large hole exposure data. Secondary development: Using development process parameters compatible with the dry film type, the PCB board after secondary exposure is developed to form a double-layer dry film structure at the PTH large holes with a diameter ≥6mm. PCB board forming: The PCB board after secondary development is formed.

2. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 1, characterized in that, The dry film is a high-resolution dry film with a thickness of <30µm.

3. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 1, characterized in that, In the large-aperture exposure data, the aperture ring size of the PTH large-aperture pattern with an aperture diameter ≥ 6 mm is the same as the corresponding aperture ring size in the outer layer pattern exposure data.

4. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 1, characterized in that, In the second film application step, the process parameters for the second film application are consistent with those for the first film application.

5. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 1, characterized in that, In the second development step, the process parameters for the second development are consistent with those for the first development.

6. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 1, characterized in that, The basic manufacturing process includes the following sub-steps: Material preparation: Select the copper-clad laminate substrate corresponding to the design plan requirements and bake it; then cut it into substrates of appropriate size according to the processing requirements, round the corners of the substrates, and polish the edges of the substrates. Inner layer pattern transfer: The inner layers of the substrate are pre-processed, and the designed circuit pattern is transferred to the copper foil surface of the substrate using an LDI exposure machine. Etching: The dry film in the areas not exposed to light is removed by developing, exposing the bare copper. The copper foil not protected by the dry film is removed by chemical etching. Then the resist layer is removed by stripping to obtain the desired inner layer circuit pattern. Lamination: Prepreg is attached to the upper and lower surfaces of the formed inner layer circuit pattern, and copper plates are attached to the upper and lower surfaces of the prepreg, and then lamination is performed by a press; Drilling: The drilling process creates a connection between the inner core board and the outer core board; Plating: Plating copper foil and electroplating processes increase the thickness of the outer copper foil layer and form a copper layer inside the holes. Outer layer pattern preprocessing: Preprocess the outer copper surface of the PCB board to remove surface contaminants and roughen the copper surface.

7. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 6, characterized in that, The pretreatment of the inner layer of the substrate includes: removing contaminants from the surface of the copper foil layer of the substrate by alkaline milling, then roughening the surface of the copper foil layer with an ultra-roughening solution, drying, heating to 75°C, and then performing dry film bonding.

8. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 6, characterized in that, In the outer layer pattern preprocessing, a volcanic ash grinding line or a medium-coarsening preprocessing line is used to preprocess the outer copper surface of the PCB board.

9. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 1, characterized in that, In the PCB board forming step, the PCB board after secondary development is sequentially etched, inspected by AOI, solder mask applied, text applied, surface coated, formed, electrical tested, FQC, FQA, and packaged to complete the overall production of the PCB board.

10. The PCB manufacturing method for solving the problem of large-hole dry film breakage according to claim 1, characterized in that, The outer layer graphic exposure data is the outer layer GTL / GBL graphic exposure data.

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