POFV product processing method and circuit board

Abstract

The invention relates to a POFV product processing method comprising the following steps: S1, providing a to-be-processed board which is a semi-finished circuit board drilled with a plurality of interlayer via holes; s2, resin hole plugging: the interlayer via holes are filled with resin; s3, surface roughening treatment: treating the surface of the to-be-processed plate subjected to resin hole plugging obtained in the step S2 by using a concentrated sulfuric acid solution, so that the roughness Ra of the exposed resin surface reaches 4-6 [mu] m; s4, preparing a conductive layer: forming a conductive carbon black layer on the surface of the resin roughened in the step S3 in a manner of spraying and adsorbing conductive carbon particles; and S5, electroplating treatment: electroplating the surface of the carbon black conductive layer to form a thickened copper layer. The conductive layer is formed by spraying and adsorbing the conductive carbon particles, a traditional chemical copper deposition process is completely replaced, and the process is simple, rapid, environmentally friendly and free of heavy metal wastewater treatment pressure.

Description

Technical Field

[0001] This invention relates to the field of printed circuit boards, and more particularly, to a method for processing POFV products and a printed circuit board thereof. Background Technology

[0002] POFV (Position-on-Video) is a resin-filled via plating technology used in PCB manufacturing, primarily to resolve conflicts between vias and pads in high-density wiring. Currently, the POFV process typically involves resin plugging, copper plating, and electroplating. Existing processes have the following problems: 1. Due to the properties of some resins, their smooth surface and chemical inertness result in a lack of effective physical anchoring and chemical bonding with the subsequently deposited metal (copper) layer; this leads to poor adhesion between the resin layer and the copper layer after electroplating, making copper layer detachment easy. 2. Forming a conductive layer on the resin surface for electroplating traditionally relies on chemical copper plating, a cumbersome process with expensive chemicals, long processing time, high energy consumption, extremely high wastewater treatment costs, and significant environmental impact. Summary of the Invention

[0003] In view of this, the present invention provides a low-cost and environmentally friendly processing method for POFV products.

[0004] The objective of this invention is achieved through the following technical solution: A method for processing a POFV product includes the following steps: S1. Provide a board to be processed, wherein the board to be processed is a semi-finished circuit board with multiple interlayer vias drilled in it; S2, Resin plugging: Filling the interlayer vias with resin; S3. Surface roughening treatment: The surface of the board to be processed after the resin is plugged in step S2 is treated with concentrated sulfuric acid solution so that the roughness of the exposed resin surface reaches Ra4~6μm. S4. Conductive layer preparation: A conductive carbon black layer is formed on the resin surface after roughening treatment in step S3 by spraying and adsorbing conductive carbon particles. S5. Electroplating treatment: Electroplating is performed on the surface of the carbon black conductive layer to form a thickened copper layer.

[0005] The aforementioned technical solution forms a conductive layer by spraying and adsorbing conductive carbon particles, completely replacing the traditional chemical copper plating process. On one hand, it avoids the complexity and high cost of chemical copper plating, which requires complex chemical systems, strict process control, long processing times, and expensive wastewater treatment. On the other hand, the conductive carbon black process is relatively simple, fast, and environmentally friendly, without the pressure of heavy metal wastewater treatment, and its equipment investment and operating costs are significantly lower than those of chemical copper plating. Furthermore, the activity of the carbon black process chemicals is not affected by the resin area of ​​the product, the chemicals have good stability, and the time from production to electroplating control can be extended to 24 hours.

[0006] In addition, by using concentrated sulfuric acid to precisely control the surface roughness of the exposed resin to Ra4 to 6 μm, sufficient micro-anchoring structure can be provided for the resin surface, significantly increasing the effective contact area between the resin and the subsequent conductive carbon layer and the final copper layer. This can effectively prevent the separation of the copper surface from the resin surface after high temperature or reflow soldering in subsequent processes.

[0007] Alternatively, in one possible implementation, the conductive layer is prepared as follows: S4.1 Charge reversal treatment: The plate to be processed after the roughening treatment in step S3 is immersed in a solution containing cyclic amine organic matter for treatment, so as to clean the resin surface and convert the charge on the resin surface from negative charge to positive charge; S4.2 Carbon particle adsorption: The plate to be processed after step S4.1 is immersed in a solution containing negatively charged conductive carbon particles, so that the negatively charged conductive carbon particles are adsorbed onto the positively charged resin surface. S4.3 Surface cleaning: Take out the board to be processed after step S4.2, and perform blow-drying, micro-etching and baking treatments in sequence to remove excess conductive carbon particles remaining in non-target areas on the board surface.

[0008] In the above technical solution, by first converting the charge on the resin surface to a positive charge and then immersing it in a solution containing negatively charged conductive carbon particles, the adsorption efficiency, density, and uniformity can be significantly improved. Cyclic amine organic compounds can convert the negative charge on the resin surface to a positive charge, which is beneficial for subsequent reactions. Charge interaction enables targeted deposition of carbon particles on the resin surface, while non-target areas (such as copper foil surfaces) show almost no adsorption due to charge repulsion or neutralization, reducing material waste and process complexity in subsequent cleaning processes.

[0009] Optionally, in one possible implementation, in step S4.1, a solution of cyclic amine organic compounds is placed in a treatment tank, and an ultrasonic generator is installed in the treatment tank to assist in cleaning the resin surface.

[0010] In the above technical solution, the high-pressure shock wave generated by the cavitation effect of ultrasound on the resin surface can effectively destroy the physical adsorption and chemical bonding between dirt and the object surface, achieving a good cleaning effect and effectively removing residual dust, oil stains and debris generated after roughening from the resin surface.

[0011] Optionally, in one possible implementation, in step S4.2, while immersing the plate to be processed in a solution containing negatively charged conductive carbon particles, the solution of negatively charged conductive carbon particles is sprayed onto the resin surface through a nozzle having an 85° fan-shaped spray angle.

[0012] In the above technical solution, impregnation and spraying work together to form a dual deposition mode of "passive adsorption + active impact". The impregnation process allows carbon particles to be uniformly adsorbed onto the resin surface through electrostatic interaction. The spraying process uses high-speed airflow to carry carbon particles to impact the resin surface at an 85° fan-shaped diffusion angle, which enhances the particle embedding depth. This can further improve the coverage of carbon particles and shorten the adsorption time.

[0013] Optionally, in one possible implementation, in step S4.3, a high-pressure air knife is used to blow away excess conductive carbon particles remaining on the surface of the board to be processed; sodium persulfate solution is used to micro-etch the copper surface of the board to be processed to remove excess conductive carbon particles attached to the copper surface.

[0014] In the above technical solution, the high-pressure air knife forms a uniform, flat airflow using compressed air. When this airflow covers the surface of the board to be processed, it creates an "air curtain effect," which effectively removes non-bonded conductive carbon particles from the board surface, preventing carbon particles from embedding into the copper surface or conductive layer in subsequent processes. Additionally, the sodium persulfate solution selectively etches the copper surface through an oxidation reaction, while simultaneously utilizing the active oxygen in the solution to decompose the organic carbon particles adhering to the copper surface, preventing residual carbon particles from affecting the adhesion of subsequent electroless copper plating.

[0015] Optionally, in one possible implementation, the board to be processed is subjected to a first water wash, an anti-oxidation treatment, and a second water wash in sequence after micro-etching and before drying.

[0016] In the above technical solution, the sodium persulfate solution remaining on the board surface after micro-etching can be quickly diluted with a single water wash, avoiding excessive consumption of subsequent antioxidants by acidic substances. It also removes newly generated copper oxide particles and residual carbon particles from the micro-etching process. Antioxidant treatment prevents oxidation of the copper surface from affecting subsequent processing, and a second water wash removes unreacted antioxidants from the board surface, preventing crystallization after drying and avoiding corrosion of the drying equipment.

[0017] Alternatively, in one possible implementation, the plate to be processed is subjected to an antioxidant treatment with a dilute sulfuric acid solution, the concentration of which is 4wt% to 6wt%.

[0018] In the above technical solution, after treatment with dilute sulfuric acid, a very thin copper sulfate hydrate film is formed on the copper surface. During the drying process, this film dehydrates to form a dense copper oxide or copper sulfate composite structure, which can block oxygen penetration and prolong the oxidation time of the copper surface.

[0019] Optionally, in one possible implementation, the concentration of the concentrated sulfuric acid solution used in step S3 is 92 wt% to 98 wt%.

[0020] In the above technical solution, the high-concentration sulfuric acid solution has extremely strong oxidizing and dehydrating properties, and can undergo selective chemical reaction with the resin surface to form a controllable micro-rough structure. By constructing a micro-rough structure of Ra4 to 6 μm on the resin surface, combined with mechanical interlocking, increased actual contact area and chemical bonding effect, the reliability requirements of special application scenarios such as high frequency, flexibility and high thermal conductivity can be met at the same time.

[0021] Optionally, in one possible implementation, during the concentrated sulfuric acid solution treatment in step S3, 0.5wt-1.5wt% of a sulfonate surfactant is added according to the total weight of the solution.

[0022] In the above technical solution, sulfonate surfactants can significantly optimize the surface roughening effect of the resin and improve the long-term stability of the bond between the resin and copper.

[0023] A circuit board is manufactured using the processing method described above.

[0024] In the above technical solution, the circuit board manufactured using the processing method of the POFV product adopts a carbon black process instead of a copper plating process. A highly conductive carbon black layer can be obtained on the resin surface without copper plating, making the process simple and environmentally friendly. The time from production to electroplating control can be extended to 24 hours, simplifying management and reducing operating costs, which is beneficial for improving the efficiency and quality of mass production. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a flowchart illustrating one embodiment. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] Please refer to Figure 1 This embodiment provides a processing method for POFV products, including the following steps: S1. Provide a board to be processed, which is a semi-finished circuit board with multiple interlayer vias already drilled. S2, Resin plugging: Filling interlayer vias with resin; S3. Surface roughening treatment: The surface of the board to be processed after the resin plugging in step S2 is treated with concentrated sulfuric acid solution to make the surface roughness of the exposed resin reach Ra4~6μm. S4. Preparation of conductive layer: A conductive carbon black layer is formed on the resin surface after roughening treatment in step S3 by spraying and adsorbing conductive carbon particles. S5. Electroplating treatment: Electroplating is performed on the surface of the carbon black conductive layer to form a thickened copper layer.

[0030] This embodiment forms a conductive layer by spraying and adsorbing conductive carbon particles, completely replacing the traditional chemical copper plating process. On one hand, it avoids the complexity and high cost of chemical copper plating, which requires complex chemical systems, strict process control, long processing times, and expensive wastewater treatment. On the other hand, the conductive carbon black process is relatively simple, fast, and environmentally friendly, without the burden of heavy metal wastewater treatment, and its equipment investment and operating costs are significantly lower than those of chemical copper plating. Furthermore, the activity of the carbon black process chemicals is not affected by the resin area of ​​the product, the chemicals have good stability, and the time from production to electroplating control can be extended to 24 hours.

[0031] Furthermore, concentrated sulfuric acid is used to precisely control the surface roughness of the exposed resin to Ra 4–6 μm. Ra 4 μm and above provides sufficient microscopic anchoring structures on the resin surface, significantly increasing the effective contact area between the resin and the subsequent conductive carbon layer and the final copper layer. Ra 6 μm and below ensures that the surface is not too rough, which could lead to uneven distribution, accumulation, or localized excessive thickness of conductive carbon particles, affecting the uniformity of subsequent electroplating and the continuity of the conductive carbon layer itself. This effectively prevents the separation of the copper surface from the resin surface after high-temperature or reflow soldering processes in later stages.

[0032] In this embodiment, the conductive layer is prepared as follows: S4.1 Charge reversal treatment: The plate to be processed after the roughening treatment in step S3 is immersed in a solution containing cyclic amine organic matter to clean the resin surface and convert the charge on the resin surface from negative to positive. In addition, thiol or silane self-assembled molecules can be modified on the roughened resin surface to form positively charged terminal groups, which can replace the cyclic amine solution treatment to achieve charge reversal. S4.2 Carbon particle adsorption: The plate to be processed after step S4.1 is immersed in a solution containing negatively charged conductive carbon particles, so that the negatively charged conductive carbon particles are adsorbed onto the positively charged resin surface; wherein, boron nitride or silver-coated copper powder can be doped into the solution containing negatively charged conductive carbon particles to form a composite conductive layer to improve the thermal conductivity. S4.3 Surface cleaning: Take out the board to be processed after step S4.2, and perform blow-drying, micro-etching and baking treatments in sequence to remove excess conductive carbon particles remaining in non-target areas on the board surface.

[0033] This embodiment significantly improves adsorption efficiency, density, and uniformity by first converting the surface charge of the resin to a positive charge and then immersing it in a solution containing negatively charged conductive carbon particles. Cyclic amine organic compounds can convert the negative charge on the resin surface to a positive charge, which is beneficial for subsequent reactions. Charge interactions enable targeted deposition of carbon particles on the resin surface, while non-target areas (such as copper foil surfaces) show almost no adsorption due to charge repulsion or neutralization, reducing material waste and process complexity in subsequent cleaning steps.

[0034] In step S4.1 of this embodiment, a solution of cyclic amine organic compounds is placed in a treatment tank, which is equipped with an ultrasonic generator. The ultrasonic transmitter is used to assist in cleaning the resin surface. The ultrasonic generator generates a cavitation effect in the cyclic amine solution through high-frequency vibration (20-100 kHz), forming micron-sized bubbles that burst instantaneously, generating local high temperature and high pressure, effectively removing residual dust, oil, and debris generated after roughening from the resin surface.

[0035] The high-pressure shock waves generated by the cavitation effect of ultrasound on the resin surface can effectively disrupt the physical adsorption and chemical bonding between dirt and the object surface, achieving excellent cleaning results and effectively removing residual dust, oil, and debris generated after roughening from the resin surface. Secondly, the stirring effect of ultrasound ensures that cyclic amine organic molecules are uniformly dispersed in the solution, avoiding uneven charge reversal on the resin surface caused by concentration gradients. This improves the coverage of subsequent carbon particle adsorption and reduces conductive blind spots. Understandably, traditional static soaking requires a longer time to achieve charge reversal, while ultrasound assistance can significantly shorten the reaction time, reduce the amount of cyclic amine solution used, and significantly reduce production costs and wastewater treatment pressure.

[0036] Furthermore, the ultrasonic parameters can be dynamically adjusted. An adjustable ultrasonic generator, with an adjustable range of 20–200 kHz, is installed. For highly crystalline resins such as PTFE, a high frequency greater than 100 kHz is used to reduce surface damage, while a low frequency of 20–40 kHz is used for epoxy resins to enhance the cleaning effect. Simultaneously, an AI algorithm monitors the solution turbidity in real time (via a fiber optic sensor) and automatically adjusts the ultrasonic power and processing time to achieve closed-loop control.

[0037] It should be noted that electrochemical cleaning combined with charge reversal can also achieve the effect of charge reversal. Specifically, the plate to be processed is used as the anode and immersed in an electrolyte containing cyclic amine. A pulsed voltage is applied, and oxygen and hydrogen bubbles are generated by the electrolysis of water to remove impurities. At the same time, the cyclic amine is directionally adsorbed onto the resin surface under the action of the electric field, thus completing the charge reversal.

[0038] In step S4.2 of this embodiment, while immersing the plate to be processed in a solution containing negatively charged conductive carbon particles, the solution of negatively charged conductive carbon particles is sprayed onto the resin surface through a nozzle with an 85° fan-shaped spray angle.

[0039] The synergistic effect of impregnation and spraying forms a dual deposition mode of "passive adsorption + active impact". In the impregnation process, carbon particles are uniformly adsorbed onto the resin surface through electrostatic interaction. Spraying uses a high-speed airflow, such as a nozzle pressure of 0.2 to 0.5 MPa, to carry carbon particles to impact the resin surface with an 85° fan-shaped diffusion angle, which enhances the particle embedding depth to 0.5 to 1 μm. This can further improve the coverage of carbon particles, especially for complex structures such as pore walls and corners, where the coverage rate is increased to over 99.5% and the adsorption time is shortened.

[0040] In addition, the spraying system is equipped with a solution recovery device. Unadsorbed carbon particles are returned to the storage tank with the airflow, and after circulation filtration, they are re-sprayed, improving the utilization rate of carbon particles. The 85° fan-shaped angle design ensures that the width of the spraying area matches the width of the board to be processed, avoiding excessive deposition at the edges or insufficient coverage in the center.

[0041] As an alternative implementation, electrostatic spraying or ultrasonic spraying can be used instead of mechanical spraying. Electrostatic spraying uses a high-voltage electrostatic field to atomize a negatively charged carbon particle solution, which is then directionally deposited onto a positively charged resin surface under the influence of the electric field. Ultrasonic spraying uses an ultrasonic transducer to vibrate and atomize the carbon particle solution, and a carrier gas transports the droplets to the resin surface; this process must be combined with an impregnation process.

[0042] In step S4.3 of this embodiment, a high-pressure air knife is used to blow away excess conductive carbon particles remaining on the surface of the board to be processed; sodium persulfate solution is used to micro-etch the copper surface of the board to be processed to remove excess conductive carbon particles attached to the copper surface.

[0043] High-pressure air knives use compressed air to create a uniform, flat airflow that forms an "air curtain effect" when covering the surface of the board to be processed. This effectively removes non-bonded conductive carbon particles from the board surface, preventing them from embedding into the copper surface or conductive layer in subsequent processes. Compared to mechanical brushing or water washing, air knife cleaning is a purely physical cleaning method that does not introduce moisture or chemical impurities. The airflow temperature is adjustable, quickly drying the board surface while removing carbon particles. Furthermore, sodium persulfate solution selectively etches the copper surface through an oxidation reaction, while simultaneously using active oxygen in the solution to decompose organic carbon particles adhering to the copper surface, preventing residual carbon particles from affecting the adhesion of subsequent electroless copper plating.

[0044] In this embodiment, the board to be processed undergoes a first water wash, an anti-oxidation treatment, and a second water wash sequentially after micro-etching and before drying. Specifically, the board is subjected to anti-oxidation treatment using a dilute sulfuric acid solution with a concentration of 4 wt% to 6 wt%.

[0045] The sodium persulfate solution remaining on the board surface after micro-etching can be quickly diluted with a single water rinse, avoiding excessive consumption of subsequent antioxidants by acidic substances. This also removes newly formed copper oxide particles and residual carbon particles generated during micro-etching. Antioxidant treatment prevents oxidation of the copper surface from affecting subsequent processing. A second water rinse removes unreacted antioxidants from the board surface, preventing crystallization after drying and avoiding corrosion of the drying equipment.

[0046] After treatment with dilute sulfuric acid, a very thin copper sulfate hydrate film will be formed on the copper surface. During the drying process, this film dehydrates to form a dense copper oxide or copper sulfate composite structure, which can block oxygen penetration and prolong the oxidation time of the copper surface.

[0047] In addition, chemical passivation can be used as an alternative to antioxidant treatment. This involves treating the copper surface with chromates (such as potassium dichromate) or chromium-free passivating agents (such as silane coupling agent KH-560) to form a dense passivation film through chemical adsorption. This results in a film layer with stronger corrosion resistance and higher hardness.

[0048] It should be noted that the concentration of the concentrated sulfuric acid solution used in step S3 of this embodiment is 92wt% to 98wt%. High-concentration concentrated sulfuric acid solution has extremely strong oxidizing and dehydrating properties, and can selectively react with the resin surface to form a controllable micro-rough structure. By constructing a micro-rough structure with a diameter of Ra 4 to 6 μm on the resin surface, combined with mechanical interlocking, increased actual contact area, and chemical bonding effects, the reliability requirements of special application scenarios such as high frequency, flexibility, and high thermal conductivity can be simultaneously met.

[0049] In addition, during the concentrated sulfuric acid solution treatment in step S3, 0.5wt-1.5wt% of a sulfonate surfactant is added. Sulfonate surfactants can significantly optimize the surface roughening effect of the resin and improve the long-term stability of the bond between the resin and copper.

[0050] This embodiment also provides a circuit board manufactured using the above processing method. The circuit board manufactured using the above-described POFV product processing method employs a carbon black process instead of a copper plating process, achieving a highly conductive carbon black layer on the resin surface without the need for copper plating. This process is simple and environmentally friendly. The time from production to electroplating control can be extended to 24 hours, simplifying management and reducing operating costs, which is beneficial for improving the efficiency and quality of mass production.

[0051] In the description of this invention, it should be understood that terms such as "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A processing method for POFV products, characterized in that, Includes the following steps: S1. Provide a board to be processed, wherein the board to be processed is a semi-finished circuit board with multiple interlayer vias drilled in it; S2, Resin plugging: Filling the interlayer vias with resin; S3. Surface roughening treatment: The surface of the board to be processed after the resin is plugged in step S2 is treated with concentrated sulfuric acid solution so that the roughness of the exposed resin surface reaches Ra4~6μm. S4. Conductive layer preparation: A conductive carbon black layer is formed on the resin surface after roughening treatment in step S3 by spraying and adsorbing conductive carbon particles. S5. Electroplating treatment: Electroplating is performed on the surface of the carbon black conductive layer to form a thickened copper layer.

2. The processing method for the POFV product according to claim 1, characterized in that, The conductive layer is prepared as follows: S4.1 Charge reversal treatment: The plate to be processed after the roughening treatment in step S3 is immersed in a solution containing cyclic amine organic matter for treatment, so as to clean the resin surface and convert the charge on the resin surface from negative charge to positive charge; S4.2 Carbon particle adsorption: The plate to be processed after step S4.1 is immersed in a solution containing negatively charged conductive carbon particles, so that the negatively charged conductive carbon particles are adsorbed onto the positively charged resin surface. S4.3 Surface cleaning: Take out the board to be processed after step S4.2, and perform blow-drying, micro-etching and baking treatments in sequence to remove excess conductive carbon particles remaining in non-target areas on the board surface.

3. The processing method for POFV products according to claim 2, characterized in that, In step S4.1, a solution of cyclic amine organic compounds is placed in a treatment tank, and an ultrasonic generator is installed in the treatment tank. The ultrasonic transmitter is used to assist in cleaning the resin surface.

4. The processing method for the POFV product according to claim 2, characterized in that, In step S4.2, while immersing the plate to be processed in a solution containing negatively charged conductive carbon particles, the solution of negatively charged conductive carbon particles is sprayed onto the resin surface through a nozzle with an 85° fan-shaped spray angle.

5. The processing method for the POFV product according to claim 2, characterized in that, In step S4.3, a high-pressure air knife is used to blow away excess conductive carbon particles remaining on the surface of the board to be processed; sodium persulfate solution is used to micro-etch the copper surface of the board to be processed to remove excess conductive carbon particles adhering to the copper surface.

6. The processing method for the POFV product according to claim 2, characterized in that, After micro-etching and before drying, the board to be processed is sequentially subjected to a first water wash, an anti-oxidation treatment, and a second water wash.

7. The processing method for the POFV product according to claim 6, characterized in that, The plate to be processed is subjected to antioxidant treatment with a dilute sulfuric acid solution, wherein the concentration of the dilute sulfuric acid solution is 4wt% to 6wt%.

8. The processing method for the POFV product according to claim 1, characterized in that, The concentration of the concentrated sulfuric acid solution used in step S3 is 92 wt% to 98 wt%.

9. The processing method for the POFV product according to claim 1, characterized in that, In step S3, during the treatment of concentrated sulfuric acid solution, 0.5wt-1.5wt% of a sulfonate surfactant is added.

10. A circuit board, characterized in that, It is prepared by the processing method described in any one of claims 1-9.

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