Production process and production equipment of printed circuit board, and printed circuit board
By employing a two-stage copper plating and drying process, the problem of incomplete copper layer coverage within blind vias was solved, achieving uniform copper layer coverage within blind vias and improving the conductivity and production quality of printed circuit boards.
Patent Information
- Application Number
- CN202511097059.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-06
- Publication Date
- 2025-12-09
AI Technical Summary
In the prior art, blind holes have small diameters and large depths, making it difficult for the flux to penetrate fully. This results in the copper layer at the bottom or corner of the blind hole not being completely covered, reducing the conductivity of the blind hole.
The process employs two copper plating steps and two drying steps, using chemical copper plating to form the first and second copper plating layers, ensuring complete coverage and uniformity of the copper layer inside the blind holes. This includes steps such as pretreatment, copper plating, drying, and cleaning, and is carried out using specialized production equipment for automated production.
This improves the uniformity and integrity of the copper plating inside the blind vias, ensuring good conductivity, enhancing the reliability and stability of the printed circuit board, and improving production quality and efficiency.
Smart Images
Figure CN121099533A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of air conditioning, in particular to a production process and production equipment of a printed circuit board and the printed circuit board. BACKGROUND
[0002] In the related art, in order to ensure the electrical performance of the printed circuit board, the size of the blind hole is usually controlled to be small. However, in the subsequent copper plating process, due to the limited penetration force of the chemical solution, the small-size blind hole is difficult to be fully penetrated by the chemical solution due to its small aperture and relatively large depth, thereby causing the copper layer at the bottom or corner of the blind hole to be incompletely covered, and reducing the conductivity of the blind hole. SUMMARY
[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a production process of a printed circuit board, which can enable the blind hole to be completely covered by the copper layer, and improve the uniformity and integrity of the copper plating layer in the blind hole.
[0004] The present application also provides a production equipment for implementing the above-mentioned production process of the printed circuit board.
[0005] The present application also provides a printed circuit board made by the above-mentioned production process of the printed circuit board.
[0006] According to the production process of the printed circuit board of the first aspect of the present application, the printed circuit board has a blind hole, and the production process comprises the following steps: a pretreatment step; a copper plating step, after the pretreatment step, the printed circuit board is immersed in a first cylinder body provided with a copper plating solution, so as to form a first copper plating layer in the blind hole; a drying step, after the copper plating step, the printed circuit board is baked to remove the water and the copper plating solution remaining in the blind hole; a secondary copper plating step, after the drying step, the printed circuit board is immersed in a second cylinder body provided with the copper plating solution, so as to form a second copper plating layer in the blind hole; a secondary drying step, after the secondary copper plating step, the printed circuit board is secondly baked to remove the water and the copper plating solution remaining in the blind hole; and an electroplating step.
[0007] According to the production process of the printed circuit board of the present application, at least the following beneficial effects are achieved: The production process of the printed circuit board of the embodiment of the present application can make the blind hole be completely covered by the copper layer through twice copper plating and twice drying processes, ensure that the copper plating layer inside the blind hole is fully covered and has uniform thickness, improve the uniformity and integrity of the copper plating layer inside the blind hole, solve the problem of incomplete copper layer deposition caused by insufficient penetration of the chemical solution in the small-diameter blind hole, ensure that the blind hole has good conductivity, thereby improving the reliability and stability of the printed circuit board, and further improving the production quality and production efficiency of the printed circuit board.
[0008] According to some embodiments of the present application, a part of the second copper plating layer is formed on the inner wall of the blind hole, and another part is formed on the surface of the first copper plating layer. According to some embodiments of the present application, the copper plating step and the secondary copper plating step respectively include the following steps: A pre-treatment step, the printed circuit board is sequentially immersed in a plurality of pre-treatment solutions to clean and activate the printed circuit board; A copper plating step, after the pre-treatment step, the printed circuit board is immersed in a copper plating solution; A post-treatment step, after the copper plating step, the printed circuit board is immersed in an anti-oxidation solution.
[0009] According to some embodiments of the present application, the copper plating step includes the following steps: The printed circuit board is soaked in the copper plating solution for 14 to 18 minutes.
[0010] According to some embodiments of the present application, a cleaning step is included before the drying step and before the secondary drying step, respectively, and the cleaning step includes the following steps: overflow water washing step, still water washing step and drying step.
[0011] According to some embodiments of the present application, a secondary pre-treatment step is further included before the secondary copper plating step, and the pre-treatment step and the secondary pre-treatment step respectively include the following steps: A plate grinding step, the printed circuit board is subjected to plate grinding treatment.
[0012] According to some embodiments of the present application, the drying step and the secondary drying step respectively include the following steps: A hot drying step, the printed circuit board is placed in a drying chamber with a temperature maintained at 75 to 85 degrees Celsius; A cold drying step, the printed circuit board is placed in a normal temperature environment.
[0013] According to some embodiments of the present application, the maximum aperture of the blind hole is D, which satisfies: D≤0.1mm. The production equipment of the printed circuit board according to the second aspect of the present application is used to implement the production process of the printed circuit board according to the first aspect of the present application.
[0014] The production equipment of the printed circuit board according to the present application has at least the following beneficial effects: The production equipment of the printed circuit board according to the present application can implement the production process of the printed circuit board according to the first aspect of the present application, and through twice copper plating and twice drying processes, the blind hole can be completely covered by the copper layer, the copper plating layer inside the blind hole is ensured to be fully covered and uniform in thickness, the uniformity and integrity of the copper plating layer inside the blind hole are improved, the problem of incomplete copper layer deposition caused by insufficient penetration of the chemical solution in the small-diameter blind hole is solved, and the blind hole is ensured to have good conductivity, thereby improving the reliability and stability of the printed circuit board, and further improving the production quality and production efficiency of the printed circuit board.
[0015] The printed circuit board according to the third aspect of the present application is made by the production process according to the first aspect of the present application.
[0016] The printed circuit board according to the present application has at least the following beneficial effects: The printed circuit board according to the present application is made by the production process of the printed circuit board according to the first aspect of the present application, and through optimization of the production process, the copper plating layer inside the blind hole is ensured to be fully covered and uniform in thickness, the uniformity and integrity of the copper plating layer inside the blind hole are improved, and the blind hole is ensured to have good conductivity, thereby improving the reliability and stability of the printed circuit board.
[0017] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS
[0018] The present application will be further described below in conjunction with the drawings and embodiments, in which: Figure 1 The step flow chart of the production process of the printed circuit board according to an embodiment of the present application. DETAILED DESCRIPTION
[0019] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, in which the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.
[0020] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down and the like, is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.
[0021] In the description of the present application, if the first, second, etc. are described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying the relative importance of the technical features or implicitly indicating or implying the number of technical features indicated or the order of the technical features indicated.
[0022] In the description of the present application, unless otherwise explicitly limited, the words such as arrangement, installation, connection and the like should be understood in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.
[0023] In the related art, a blind hole structure is often used to realize interlayer interconnection in the manufacturing process of a printed circuit board. With the development of miniaturization of electronic devices, the aperture of the blind hole is gradually reduced to improve the wiring density. When dealing with small-aperture blind holes, the traditional copper deposition process is limited by the flowability of the chemical solution, resulting in insufficient metal deposition at the deep part of the blind hole, and the bottom of the hole wall is prone to have hollow or uneven thickness of the plated layer, which directly affects the reliability of the circuit conduction. Especially in the high-frequency signal transmission scenario, the plated layer defects can cause signal attenuation and impedance mismatch problems, which seriously restrict the product yield.
[0024] To solve the above problems, some embodiments of the present application provide a production process of a printed circuit board, which is suitable for a printed circuit board with a blind hole, and can enable the blind hole to be completely covered by a copper layer, thereby improving the uniformity and integrity of the copper plating layer in the blind hole. For details, refer to Figure 1 the production process of the printed circuit board is described.
[0025] Referring to Figure 1 In the embodiments of the present application, the production process of the printed circuit board includes the following steps: a pretreatment step; a copper deposition step, after the pretreatment step, the printed circuit board is immersed in a first cylinder body into which a copper deposition solution is poured, so as to form a first copper plating layer by plating copper in the blind hole; a drying step, after the copper deposition step, the printed circuit board is baked to remove the water and the copper deposition solution remaining in the blind hole; a secondary copper deposition step, after the drying step, the printed circuit board is immersed in a second cylinder body into which a copper deposition solution is poured, so as to form a second copper plating layer by plating copper in the blind hole; a secondary drying step, after the secondary copper deposition step, the printed circuit board is baked again to remove the water and the copper deposition solution remaining in the blind hole; an electroplating step.
[0026] Specifically, in the embodiment of the present application, the pretreatment step refers to cleaning and roughening the surface of the substrate, which can be achieved by combining chemical cleaning with mechanical grinding to create good interface conditions for subsequent metal deposition. The copper deposition step and the secondary copper deposition step both refer to forming a conductive layer in the blind hole by chemical copper plating. The drying step and the secondary drying step are both to remove the residual liquid in the blind hole.
[0027] It can be understood that, in the embodiment of the present application, the first copper deposition establishes a basic conductive layer in the blind hole, and the drying process eliminates the hindrance of residual liquid to the penetration of the plating solution, which not only prevents oxidation and water retention in the blind hole and avoids the occurrence of copper biting, but also removes the residual moisture and chemicals in the hole in time, protects the deposited copper layer, and creates better conditions for the subsequent copper deposition process. The secondary copper deposition is carried out on the dry hole wall surface to fill the possible micro-pores in the first plating layer.
[0028] Based on this, in the embodiment of the present application, part of the second copper plating layer is formed on the inner wall of the blind hole, and the other part is formed on the surface of the first copper plating layer. It can be understood that, in the first copper deposition step, the inner wall of the blind hole is preliminarily covered by the first copper plating layer, but due to the small aperture or complex structure of the blind hole, there may be local areas that are not completely covered. Through the secondary copper deposition step, the second copper plating layer is deposited on the surface of the first copper plating layer, while filling the blind hole inner wall area not covered by the first copper deposition, thereby forming a continuous conductive layer. The plating layer of two times of copper deposition can effectively eliminate the conductive blind area in the blind hole and ensure the uniform distribution of the copper layer in the hole. Since the traditional copper deposition process only performs one-time copper deposition treatment, for small-aperture blind holes, the copper layer in the hole is easily not completely covered due to insufficient penetration of the plating solution. In comparison, the embodiment of the present application improves the integrity and continuity of the copper layer in the blind hole by the secondary copper deposition step, which further fills the defect area based on the first deposition, thereby solving the problem of incomplete coverage of the copper layer in the small-aperture blind hole, ensuring the formation of a continuous path in the conductive layer in the blind hole, avoiding the interruption of signal transmission or abnormal resistance caused by local non-coverage, and thereby improving the electrical reliability of the printed circuit board.
[0029] In the embodiment of the present application, the electroplating step is implemented after two times of copper deposition, so that the continuous conductive layer formed can be fully utilized to achieve uniform current distribution, and finally a complete and dense metal plating layer is obtained, which significantly improves the product qualification rate and long-term reliability of the printed circuit board.
[0030] In the embodiments of the present application, the copper plating step and the secondary copper plating step each include the following steps: a pretreatment step of sequentially immersing the printed circuit board in a plurality of pretreatment solutions to clean and activate the printed circuit board; a copper plating step of immersing the printed circuit board in a copper plating solution after the pretreatment step; and a post-treatment step of immersing the printed circuit board in an anti-oxidation solution after the copper plating step.
[0031] In the embodiments of the present application, the pretreatment step refers to a process of cleaning the surface of the printed circuit board and the inside of the blind hole by a chemical solution, and can be achieved by sequentially treating with an acidic cleaner, a micro-etching solution and an activator. This step can remove surface contaminants and form an active surface to enhance the bonding force of the copper layer. Specifically, in one example, the pretreatment step includes soaking in a bulk agent, double water washing, soaking in potassium permanganate, water washing, high-level pre-neutralization, high-level double water washing, neutralization, double water washing, oil removal, hot water washing, double water washing, micro-etching, double water washing, pre-soaking, activation, double water washing, speed-up, double water washing. It should be noted that each execution step included in the above pretreatment step can be achieved by a tank loaded with clean water or different solutions, and the composition and ratio of the solutions can be selected and set according to actual conditions.
[0032] In the embodiments of the present application, the copper plating step refers to a process of forming a conductive layer by electroless copper plating, and can be achieved by soaking in a copper plating solution containing copper ions, a reducing agent and a complexing agent. This step deposits a copper layer on the inner wall of the blind hole through a self-catalytic reaction. The post-treatment step refers to a process of anti-oxidation treatment on the surface of the copper layer, and can be achieved by soaking in an anti-oxidation solution containing benzotriazole. This step can prevent the copper layer from undergoing oxidation reaction in subsequent processes. In addition, the post-treatment step can also include cleaning, drying and other steps.
[0033] In one example, the copper plating step and the secondary copper plating step each include the following steps: bulk agent removal, glue removal, pre-neutralization, neutralization, oil removal, micro-etching, pre-soaking, activation, acceleration, copper plating, anti-oxidation. Specifically, each of the above steps is respectively provided with a cylinder loaded with a corresponding solution, wherein the cylinder for performing the bulk agent step is loaded with white water prevention agent, phosphoric acid, sodium hydroxide, etc.; the cylinder for performing the glue removal step is loaded with potassium permanganate, sodium hydroxide, etc.; the cylinder for performing the pre-neutralization step is loaded with hydrogen peroxide, sulfuric acid, etc.; the cylinder for performing the neutralization step is loaded with oxalic acid, sodium oxalate, sulfuric acid, etc.; the cylinder for performing the pre-oil removal step is loaded with sodium carbonate, etc.; the cylinder for performing the micro-etching step is loaded with a micro-etching agent, sulfuric acid, etc.; the cylinder for performing the pre-soaking step is loaded with sodium chloride, hydrogen chloride, etc.; the cylinder for performing the activation step is loaded with sodium chloride, palladium chloride, hydrogen chloride, stannous chloride, etc.; the cylinder for performing the acceleration step is loaded with sodium sulfite, sodium carbonate, etc.; the cylinder for performing the copper plating step is loaded with a copper ion solution, formaldehyde, ethylenediamine acetic acid disodium, sodium hydroxide, etc.; and the cylinder for performing the anti-oxidation step is loaded with benzotriazole, etc.
[0034] In the embodiment of the present application, the copperizing step comprises the following steps: immersing the printed circuit board in the copper plating solution for 14 to 18 minutes. Immersing the printed circuit board in the copper plating solution for 14 to 18 minutes refers to the time range for the printed circuit board to be completely immersed in the copper plating solution for chemical reaction, which can be achieved by using a timing device to control the immersion time. This time period is set to ensure that the copper plating solution fully penetrates into the blind hole to complete the chemical copper plating, and to avoid problems such as excessive consumption of active ingredients in the solution or excessive thickness of the plated layer due to too long time.
[0035] It can be understood that, in the copperizing step, when the printed circuit board is immersed in the copper plating solution, copper ions in the solution enter the inside of the blind hole through diffusion. Within the time range of 14 to 18 minutes, the solution can gradually cover the inner wall and bottom of the blind hole to form a uniform copper deposition layer. For example, when the immersion time is insufficient, the deep part of the blind hole may not have a complete plated layer due to insufficient penetration of the solution; when the immersion time is too long, the concentration of effective ingredients in the solution decreases, which in turn reduces the deposition efficiency. By reasonably controlling the immersion time in this range, the embodiment of the present application can ensure the continuity and density of the copper plated layer in the blind hole.
[0036] In the embodiment of the present application, a cleaning step is included before the drying step and before the secondary drying step, which comprises the following steps: overflow water washing step, still water washing step and drying step. It should be noted that in this embodiment, the printed circuit board needs to be cleaned after each copper plating to remove the residual copper plating solution attached to the inner wall and surface of the blind hole.
[0037] Specifically, the overflow water washing step refers to washing the surface of the printed circuit board by overflow, which can be achieved by continuously injecting clean water into an overflow tank and overflowing to the drain, for flushing the residual copper plating solution attached to the inner wall and surface of the blind hole. The still water washing step refers to immersing the printed circuit board in a still cleaning water environment, which can be achieved by using a fixed water washing tank for stationary immersion, to further dissolve the residual small particles in the blind hole through the diffusion of water molecules. The drying step refers to physically adsorbing the surface of the printed circuit board by using a water-absorbing material, which can be achieved by using a dust-free cloth or a sponge roller contact wiping method to remove the residual water film on the opening of the blind hole and the board surface.
[0038] In the embodiment of the present application, after the copper plating step is completed, the printed circuit board is transferred to the cleaning station. First, the overflow water washing step is used to continuously flush the inside and outside of the blind hole to flush most of the residual copper plating solution; then the still water washing tank is used for immersion to fully dissolve the residual small particles in the deep part of the blind hole; finally, the drying step is used to remove the surface moisture. In the embodiment of the present application, a secondary pretreatment step is further included before the secondary copper plating step, and the pretreatment step and the secondary pretreatment step respectively include the following steps: a plate grinding step, and the printed circuit board is subjected to plate grinding treatment. Specifically, the plate grinding step is required before each copper plating. It can be understood that the plate grinding step refers to treating the surface of the printed circuit board by physical or chemical means, which can be realized by mechanical grinding or chemical grinding process, for removing the surface oxide layer, contaminants and increasing the surface roughness, and improving the bonding force between the subsequent copper plating layer and the substrate.
[0039] It should be noted that after the first copper plating, the blind hole may be left with copper plating solution crystallization or oxidation products. Through the plate grinding step in the secondary pretreatment, the surface residues generated in the first copper plating process can be effectively removed, and the activity state of the inner wall of the blind hole is restored. When the printed circuit board enters the secondary copper plating, the clean inner wall of the blind hole is more conducive to the infiltration of the copper plating solution, so that the second copper plating layer uniformly covers the bottom and sidewall of the blind hole, and the plating defects caused by surface contamination are avoided.
[0040] In the embodiment of the present application, the drying step and the secondary drying step respectively include the following steps: a hot drying step, the printed circuit board is placed in a drying chamber with a temperature maintained at 75-85°C; and a cold drying step, the printed circuit board is placed in a normal temperature environment. Specifically, the hot drying step refers to removing the residual liquid in the blind hole by external heating, which can be realized by using a constant temperature drying equipment, and the water and copper plating solution are evaporated quickly by controlling the temperature range. The cold drying step refers to eliminating thermal stress by natural temperature balance, which can be realized by using a normal temperature ventilation environment, so as to avoid deformation of the printed circuit board due to sudden cooling.
[0041] Specifically, since the cleaning step is performed after each copper plating, after copper plating and secondary copper plating, the printed circuit board successively experiences hot drying and cold drying. The temperature in the hot drying stage is controlled in the range of 75-85°C, for example, an industrial oven is used to maintain a stable temperature, so as to make the residual liquid in the blind hole evaporate fully. Then the board is transferred to a normal temperature environment, for example, placed in a ventilated workshop, and the whole board is cooled by using the natural temperature to eliminate the local stress caused by high temperature. The two drying processes are matched to ensure that there is no liquid residue on the inner wall of the blind hole and the surface of the copper plating layer.
[0042] In the embodiment of the present application, the maximum aperture of the blind hole is D, which satisfies: D≤0.1mm. It should be noted that the embodiment of the present application is aimed at the printed circuit board with a blind hole whose maximum aperture is not more than 0.1mm. It can be understood that when the maximum aperture of the blind hole is less than or equal to 0.1mm, the aperture of the blind hole is too small, and due to the limited permeability and diffusion capacity of the chemical liquid, the liquid flow in the micro blind hole with an aperture less than or equal to 0.1mm is limited, and the liquid is difficult to fully penetrate to the bottom and sidewall corner of the blind hole.
[0043] Therefore, the production process of the printed circuit board in the embodiment of the present application can make the blind hole completely covered by the copper layer through twice copper plating and twice drying processes, ensure that the copper plating layer inside the blind hole is fully covered and has uniform thickness, improve the uniformity and integrity of the copper plating layer inside the blind hole, solve the problem of incomplete copper layer deposition caused by insufficient penetration of the chemical solution in the small-aperture blind hole, ensure that the blind hole has good electrical conductivity, thereby improving the reliability and stability of the printed circuit board, and further improving the production quality and production efficiency of the printed circuit board.
[0044] In an example, the production process of the printed circuit board comprises the following steps executed in sequence: plate grinding step-pretreatment step-copper plating step-post-treatment step-overflow water washing step-still water washing step-drying step-plate grinding step-pretreatment step-copper plating step-post-treatment step-overflow water washing step-still water washing step-drying step-second drying step-electroplating step.
[0045] The embodiment of the present application also proposes a production device for a printed circuit board, which is used to implement the production process of the above-mentioned embodiments. Specifically, the production device refers to a combination of devices for executing the printed circuit board manufacturing process, which can be realized by an automatic production line, for example, by connecting each process unit through a conveying device. The pretreatment unit is used for cleaning and activating the surface of the substrate, which can be realized by a chemical cleaning tank or a plate grinder. The copper plating unit includes an immersion tank for immersing the substrate into a copper plating solution to form a copper plating layer, for example, a multi-cylinder structure is configured to support multiple copper plating. The drying unit removes residual liquid through hot air circulation or infrared heating device, for example, a temperature-controllable oven is provided. The second copper plating unit and the second drying unit can have the same structure as the first copper plating and drying unit, but are independently arranged to avoid process interference.
[0046] The production device for a printed circuit board in the embodiment of the present application can implement the production process of the printed circuit board in the first aspect of the embodiment, which can make the blind hole completely covered by the copper layer through twice copper plating and twice drying processes, ensure that the copper plating layer inside the blind hole is fully covered and has uniform thickness, improve the uniformity and integrity of the copper plating layer inside the blind hole, solve the problem of incomplete copper layer deposition caused by insufficient penetration of the chemical solution in the small-aperture blind hole, ensure that the blind hole has good electrical conductivity, thereby improving the reliability and stability of the printed circuit board, and further improving the production quality and production efficiency of the printed circuit board.
[0047] Since the production device for a printed circuit board adopts all the technical solutions of the production process of the printed circuit board in the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.
[0048] The embodiment of the present application also provides a printed circuit board, which is manufactured by the manufacturing process of the printed circuit board of the above embodiment.
[0049] The printed circuit board of the embodiment of the present application is manufactured by the manufacturing process of the printed circuit board of the first aspect, and the uniformity and integrity of the copper plating layer in the blind hole are improved by optimizing the manufacturing process, so that the blind hole has good conductivity, thereby improving the reliability and stability of the printed circuit board.
[0050] Since the printed circuit board adopts the technical solutions of the manufacturing process of the printed circuit board of the above embodiment, at least all the beneficial effects brought by the technical solutions of the above embodiment are achieved, and details are not repeated here.
[0051] Of course, the present application is not limited to the above embodiments, and those skilled in the art can make equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.
Claims
1. A manufacturing process for printed circuit boards, characterized in that, The printed circuit board has blind vias, and the manufacturing process includes the following steps: Preprocessing steps; In the copper plating step, after the pretreatment step, the printed circuit board is immersed in a first tank containing a copper plating solution to form a first copper plating layer in the blind holes. The drying step involves baking the printed circuit board after the copper plating step to remove residual moisture and the copper plating solution from the blind vias. In the second copper plating step, after the drying step, the printed circuit board is immersed in a second tank containing the copper plating solution to form a second copper plating layer in the blind holes. The secondary drying step involves baking the printed circuit board a second time after the secondary copper plating step to remove residual moisture and copper plating solution from the blind vias. Electroplating steps.
2. The manufacturing process of the printed circuit board according to claim 1, characterized in that, A portion of the second copper plating is formed on the inner wall of the blind hole, and another portion is formed on the surface of the first copper plating.
3. The manufacturing process of the printed circuit board according to claim 1, characterized in that, The copper plating step and the secondary copper plating step each include the following steps: The pretreatment step involves immersing the printed circuit board in a variety of pretreatment solutions in sequence to clean and activate the printed circuit board. In the copper plating step, after the pretreatment step, the printed circuit board is immersed in a copper plating solution. In the post-processing step, after the copper plating step, the printed circuit board is immersed in an antioxidant solution.
4. The manufacturing process of the printed circuit board according to claim 3, characterized in that, The copper melting step includes the following steps: The printed circuit board is continuously immersed in the copper plating solution for 14 to 18 minutes.
5. The manufacturing process of the printed circuit board according to claim 1, characterized in that, A cleaning step is included before the drying step and before the secondary drying step, and the cleaning step includes the following steps: an overflow water washing step, a still water washing step, and a vacuum drying step.
6. The manufacturing process of the printed circuit board according to claim 1, characterized in that, A secondary pretreatment step is included before the secondary copper plating step. The pretreatment step and the secondary pretreatment step each include the following steps: The grinding step involves grinding the printed circuit board.
7. The manufacturing process of the printed circuit board according to claim 1, characterized in that, The drying step and the secondary drying step each include the following steps: In the heat drying step, the printed circuit board is placed in a drying chamber where the temperature is maintained at 75 degrees Celsius to 85 degrees Celsius. The cold drying step involves placing the printed circuit board in a room temperature environment.
8. The manufacturing process of the printed circuit board according to claim 1, characterized in that, The maximum diameter of the blind hole is D, which satisfies: D≤0.1mm.
9. Printed circuit board production equipment, characterized in that, The production equipment is used to implement the production process as described in any one of claims 1 to 8.
10. A printed circuit board, characterized in that, The printed circuit board is manufactured using the production process described in any one of claims 1 to 8.