Copper electroplating method for PCB (Printed Circuit Board)

Abstract

The invention provides a PCB (Printed Circuit Board) copper electroplating method which comprises the following steps: immersing a PCB into an electroplating bath for copper plating, and separating out copper ions in an anode material to a copper surface of the PCB so as to thicken the copper surface of the PCB; when it is detected that copper particles exist on the copper surface of the thickened PCB, electroplating operation is stopped; the current density in the electroplating tank is reduced, electrolysis is conducted for a preset duration after reduction, the anode material is subjected to vibration treatment till the anode material is filled in a saturated mode and does not descend, and a micro-etching agent is added into the electroplating tank to dissolve anode mud; the electroplating liquid is taken out of the electroplating bath and filtered, and the electroplating liquid is filtered and put into the electroplating bath again; and after the electroplating liquid is filtered, adding the electroplating liquid into the electroplating pool again, and continuously electroplating the PCB. According to the technical scheme of the embodiment, a worker can visually confirm the deposition degree of the anode mud in the electroplating bath, and the current distribution uniformity degree in the electroplating bath is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB board electroplating, and particularly relates to a method for copper electroplating of a PCB board. Background Art

[0002] Currently, the copper electroplating method for a PCB board usually immerses the PCB board into an electroplating tank filled with chemical solution, and performs copper electroplating treatment on the PCB board through the anode material and the cathode material in the electroplating tank of the chemical solution. After copper electroplating, copper particles will appear on the copper foil layer of the PCB board, and anode slime will be formed on the surface of the anode material, and the anode slime is adsorbed by the anode bag. In the prior art, the treatment of the anode slime is mostly to take out the anode bag in the electroplating tank to avoid excessive deposition of anode slime in the anode bag. However, since the anode bag is usually arranged at the bottom of the electroplating tank, the staff cannot effectively confirm the deposition degree of the anode slime in the anode bag, resulting in blockage or excessive deposition in the anode bag, uneven current distribution in the electroplating tank, and safety hazards such as local overheating or electric shock. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a method for copper electroplating of a PCB board, which can enable the staff to visually confirm the deposition degree of the anode slime in the electroplating tank and improve the uniformity of the current distribution in the electroplating tank.

[0004] In a first aspect, an embodiment of the present invention provides a method for copper electroplating of a PCB board, which is applied to an electroplating bath. An anode material, a cathode material and a titanium basket are placed in the electroplating bath. The anode material is placed inside the titanium basket. An electroplating solution is put into the electroplating bath, and the electroplating solution submerges the anode material, the cathode material and the titanium basket. The method includes: Immerse the PCB board into the electroplating tank for copper plating, and precipitate copper ions in the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board; Stop the electroplating operation when copper particles are detected on the thickened copper surface of the PCB board; Reduce the current density in the electroplating bath, electrolyze for a preset duration after reduction, vibrate the anode material until the anode material is saturated and does not drop, add a micro-etchant into the electroplating tank, and dissolve the anode slime; Take out the electroplating solution from the electroplating tank and filter it, filter the electroplating solution and then put it back into the electroplating tank; After completing the filtration treatment of the electroplating solution, add the electroplating solution back into the electroplating bath and continue the electroplating treatment of the PCB board.

[0005] In some embodiments of the present invention, before immersing the PCB board into the electroplating bath for copper plating, the method further includes: Determine the type of chemical solution, the thickness of the copper foil layer of the PCB board, and the copper plating time of the PCB board; Remove the oil stain and metal oxide layer on the surface of the PCB board, and wash the PCB board with pure water; Determine the surface requirements of the PCB board, and determine the protection method of the PCB board according to the surface requirements; Contact the surface of the copper foil layer with the chemical solution and perform high-temperature treatment; Perform acid pickling on the PCB board.

[0006] In some embodiments of the present invention, before performing vibration treatment on the anode material, the method further includes: Confirm the first current density in the electroplating bath; When the first current density drops to a preset current density range, perform low-current electrolysis on the anode mud on the surface of the anode material to make the anode mud separate from the surface of the anode material.

[0007] In some embodiments of the present invention, the current density range is 0.2 ASD to 0.5 ASD.

[0008] In some embodiments of the present invention, after adding a micro-etching agent into the electroplating bath and dissolving the anode mud, it further includes: Add hydrogen peroxide into the electroplating solution and heat the electroplating solution; When the electroplating solution is heated to a first preset temperature, perform first air stirring on the electroplating solution; When the electroplating solution undergoes the air stirring for a first preset duration, filter the electroplating solution.

[0009] In some embodiments of the present invention, the filtering of the electroplating solution includes: Stop the first air stirring, and pour the adsorption material into the electroplating solution; When the adsorption material is completely dissolved in the electroplating solution, perform second air stirring on the electroplating solution, and control the electroplating solution to be in a heat preservation state until the second air stirring reaches a second preset duration; Turn off the second air stirring, and raise the temperature of the electroplating solution to precipitate the adsorption material; When the temperature of the electroplating solution drops to a second preset temperature, put a PP filter element into the electroplating solution to filter the electroplating solution.

[0010] In some embodiments of the present invention, the temperature of the electroplating solution is controlled between 20°C and 40°C, and the etching time of the micro-etchant is twenty seconds to forty seconds.

[0011] In some embodiments of the present invention, after the vibration treatment of the anode material, the method further includes: When metal particles precipitate on the surface of the anode material, it is confirmed whether the metal particles are suspended on the surface layer of the electroplating solution. When the metal particles are suspended on the surface layer of the electroplating solution, it is determined that the metal particles are anode sludge particles; Alternatively, it is confirmed whether there are copper particles on the surface of the copper foil layer. When the copper particles on the surface of the copper foil layer decrease or disappear, it is determined that the anode sludge becomes loose; Alternatively, a sample of the electroplating solution is taken to obtain the copper ion concentration in the electroplating solution. When the copper ion concentration is lower than the first preset concentration, it is determined that the anode sludge becomes loose.

[0012] In some embodiments of the present invention, the thickness of the copper foil layer is 5μm to 0.8μm.

[0013] In some embodiments of the present invention, the vibration treatment of the anode material includes: Using a metal rod to strike the anode material, wherein the metal stability of the metal rod is greater than that of the anode material.

[0014] The PCB board copper electroplating method according to the embodiments of the present invention has at least the following beneficial effects: Immerse the PCB board into the electroplating tank for copper plating, precipitate copper ions from the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board; stop the electroplating operation when copper particles are detected on the thickened copper surface of the PCB board; reduce the current density in the electroplating bath, electrolyze for a preset duration after reduction, perform vibration treatment on the anode material until the anode material is saturated and does not decrease, add a micro-etchant into the electroplating tank to dissolve the anode sludge; take out the electroplating solution from the electroplating tank and filter it, filter the electroplating solution and put it back into the electroplating tank; after completing the electroplating solution filtration treatment, add the electroplating solution back into the electroplating bath and continue the electroplating treatment of the PCB board. According to the technical solution of this embodiment, it can enable the staff to visually confirm the deposition degree of the anode sludge in the electroplating tank and improve the current distribution uniformity in the electroplating tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a flowchart of a PCB board copper electroplating method provided by an embodiment of the present invention; Figure 2 is a flowchart of a pretreatment operation for a PCB board provided by an embodiment of the present invention. Figure 3 It is a flowchart of pounding the anode material provided by an embodiment of the present invention until the filling of the anode material is saturated and there is no decrease. Figure 4 It is a flowchart of adding a micro-etching agent into an electroplating bath and dissolving the anode sludge provided by an embodiment of the present invention. Figure 5 It is a flowchart of filtering the electroplating solution provided by an embodiment of the present invention. Figure 6 It is a flowchart of determining that the anode sludge on the surface of the anode material becomes loose provided by an embodiment of the present invention. Figure 7 It is a flowchart of pounding the anode material provided by an embodiment of the present invention. Detailed implementation manners

[0016] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention.

[0017] In the description of the present invention, it should be understood that for the orientation description, such as up, down, front, back, left, right, etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0018] In the description of the present invention, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If the first and second are described only for the purpose of distinguishing technical features, they should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0019] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0020] An embodiment of the present invention provides a method for copper electroplating of a PCB board, which is applied to an electroplating bath. An anode material, a cathode material, and a titanium basket are placed in the electroplating bath. The anode material is placed inside the titanium basket. An electroplating solution is placed in the electroplating bath, and the electroplating solution submerges the anode material, the cathode material, and the titanium basket. The method includes: immersing the PCB board into an electroplating tank for copper plating, depositing copper ions in the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board; stopping the electroplating operation when copper particles are detected on the thickened copper surface of the PCB board; reducing the current density in the electroplating bath, electrolyzing for a preset duration after reduction, vibrating the anode material until the anode material is saturated and there is no decrease, adding a micro-etching agent into the electroplating tank to dissolve the anode sludge of the anode material; taking out the electroplating solution from the electroplating tank and filtering it, filtering the electroplating solution and then putting it back into the electroplating tank; after completing the filtering process of the electroplating solution, adding the electroplating solution back into the electroplating bath and continuing the electroplating process for the PCB board. According to the technical solution of this embodiment, it can enable the staff to visually confirm the deposition degree of the anode sludge in the electroplating tank and improve the uniformity of the current distribution in the electroplating tank.

[0021] It should be noted that during the copper electroplating process of the PCB board, the anode material will gradually dissolve, and the generated anode sludge will deposit in the electroplating tank, especially adhering to the surface of the anode material. By vibrating the anode material to judge whether the anode sludge deposited on the surface of the anode material is loose, when the anode sludge starts to loosen, fine particles will fall off from the surface of the anode material and suspend in the electroplating solution, causing the electroplating solution to become turbid. Through the observation of the fine particles on the surface of the electroplating solution by the staff, the staff can visually confirm the deposition degree of the anode sludge in the electroplating tank and improve the uniformity of the current distribution in the electroplating tank.

[0022] Next, based on the accompanying drawings, the control method of the embodiment of the present invention will be further elaborated.

[0023] Refer to Figure 1 , Figure 1 which is a flowchart of a method for copper electroplating of a PCB board provided by an embodiment of the present invention. The method for copper electroplating of the PCB board includes but is not limited to the following steps: Step S11, immersing the PCB board into an electroplating tank for copper plating, depositing copper ions in the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board; It should be noted that thickening the copper surface can reduce the resistance of current transmission, lower the resistance of the circuit, thereby reducing the energy loss during signal transmission, improving the efficiency and speed of signal transmission, and ensuring the high-performance operation of electronic devices.

[0024] It should be noted that when copper electroplating is performed on a PCB board, a layer of insoluble or hardly soluble substance deposition (i.e., anode sludge) is formed on the surface of the anode material due to electrochemical action. When the copper electroplating method is used for the PCB board, since the electroplating solution placed in the electroplating tank usually has a relatively dark color, it is impossible for the staff to visually judge the accumulation degree of the anode sludge in the electroplating tank. Therefore, in this embodiment, by placing the anode material in a titanium basket, the titanium basket restricts the position and movement range of the anode material in the electroplating bath. Those skilled in the art can understand that when the copper electroplating method is used for the PCB board, the electroplating tank is usually provided with artificial waves to continuously wash the PCB board with the electroplating solution. Therefore, the staff can visually observe whether anode sludge is deposited on the surface of the anode material.

[0025] It should be noted that in this embodiment, the anode material is a copper ball, and multiple copper balls are placed inside the titanium basket. The copper balls have a large surface area, can provide sufficient copper ions for the PCB board for use in the electroplating process, and effectively ensure the stable supply of copper ions during the electroplating process, so that the copper foil layer formed on the surface of the PCB board is more uniform and dense.

[0026] Exemplarily, the anode material in this embodiment can also use phosphor copper balls as the electroplating anode material. When the PCB board is electroplated, a black phosphorus film will be formed on the surface of the phosphor copper balls. The phosphorus film has good metal conductivity, can effectively control the electroplating speed, improve the corrosion resistance of the copper foil layer on the surface of the PCB board, and can effectively reduce the generation of anode sludge and improve the quality and performance of the coating.

[0027] Step S12, when it is detected that there are copper particles on the copper surface of the thickened PCB board, stop the electroplating operation; It should be noted that the presence of copper particles will make the surface of the PCB board uneven. In subsequent processes, such as film laminating and lithography, the uneven surface will cause uneven adhesion of the film layer or photoresist, affecting the accuracy of pattern transfer, and even causing problems such as short circuits or open circuits in the circuit. Stopping the electroplating operation in a timely manner can effectively prevent the occurrence of the above problems and avoid a large number of defective products in subsequent processes. During the electroplating process, copper ions are continuously deposited on the copper surface of the PCB board under the action of an electric field. When copper particles have appeared on the copper surface of the thickened PCB board, continuing electroplating may cause the copper particles to grow and become larger. Stopping the electroplating operation can prevent copper ions from continuing to deposit on the copper particles and avoid further deterioration of the influence of the copper particles on the performance and quality of the PCB board.

[0028] Step S13, reduce the current density in the electroplating bath, electrolyze for a preset duration after reduction, perform vibration treatment on the anode material until the anode material is saturated and does not decrease, and add a micro-etching agent to the electroplating tank to dissolve the anode sludge of the anode material; It should be noted that reducing the current density can make the electrochemical reaction in the electroplating process more uniform and stable. This helps to reduce the difference in the deposition rate of copper ions on the surface of the cathode (PCB board), avoiding the situation of locally too thick or too thin copper plating, thereby improving the uniformity and consistency of the copper plating layer and enhancing the overall quality of the PCB board. At a lower current density, the reaction on the electrode surface is more controllable, and the occurrence of side reactions such as hydrogen evolution can be reduced. The reduction of side reactions can not only avoid defects such as pores or pockmarks on the surface of the PCB board, but also improve the electroplating efficiency and reduce energy consumption. The vibrating anode material can break the diffusion layer formed on the anode surface, making the solution around the anode flow more uniformly. Furthermore, it promotes the uniform dissolution of the anode material, avoiding local passivation or uneven dissolution on the anode surface, ensuring that the anode can continuously and stably supply copper ions and maintaining the stability of the electroplating process. Vibration can make the anode mud shed from the anode surface break away from the anode in time, avoiding its accumulation on the anode surface. The accumulation of anode mud may hinder the normal dissolution of the anode and affect the electroplating effect. Through vibration treatment, the anode mud can be more easily dispersed in the electroplating solution, facilitating subsequent treatment, and at the same time reducing the anode passivation phenomenon caused by the accumulation of anode mud and prolonging the service life of the anode.

[0029] Furthermore, after the anode mud on the surface of the anode material falls off into the electroplating solution, a micro-etching agent is added to dissolve the anode mud, and the metal ions generated after the dissolution of the anode mud are recycled, thereby reducing the consumption and waste of copper electroplating raw materials. At the same time, dissolving the anode mud with the micro-etching agent helps to reduce energy consumption and environmental pollution during the electroplating process, thereby maintaining the clarity and stability of the electrolyte, prolonging the service life of the electroplating tank and improving the electroplating efficiency.

[0030] It should be noted that the micro-etching agent used in this embodiment includes but is not limited to copper sulfate solution.

[0031] Step S14, take out the electroplating solution from the electroplating tank and filter it, filter the electroplating solution and then put it back into the electroplating tank; It should be noted that during the electroplating process, various impurity particles may be mixed into the electroplating solution, such as anode sludge generated by anode dissolution, dust in the air, metal debris generated by equipment wear, etc. If these impurity particles remain in the electroplating solution, they may adhere to the surface of the PCB board, resulting in defects such as particles and pitting on the board surface, affecting the appearance and performance of the PCB board. Through filtration, these impurity particles can be effectively removed, improving the surface quality of the PCB board. If the impurity particles accumulate in the electroplating solution, they may clog components such as pipelines and nozzles of the electroplating equipment, affecting the normal circulation and spraying of the electroplating solution, resulting in uneven electroplating. Filtering the electroplating solution can prevent the impurity particles from clogging the equipment, ensuring the normal operation of the electroplating equipment and maintaining stable electroplating process conditions. In addition, the presence of impurities may trigger some side reactions, consuming the effective components in the electroplating solution, thereby reducing the performance and service life of the electroplating solution. By removing the impurities in the electroplating solution through filtration, the occurrence of side reactions can be reduced, making the chemical composition in the electroplating solution more stable, thereby prolonging the service life of the electroplating solution and reducing production costs.

[0032] It can be understood that the electroplating solution after filtration is purer, and its properties such as conductivity are more stable, which is beneficial to improving the deposition efficiency of copper ions on the surface of the PCB board, making the electroplating process more efficient, shortening the electroplating time, and improving production efficiency.

[0033] Step S15, after completing the filtration treatment of the electroplating solution, add the electroplating solution back into the electroplating tank and continue the electroplating treatment of the PCB board.

[0034] It should be noted that through operations such as reducing the current density, electrolyzing for a preset duration, vibrating the anode material, and adding a micro-etching agent, the electroplating conditions have been improved in multiple aspects, which helps copper ions deposit more evenly on the PCB board during subsequent electroplating, reducing the generation of new copper particles, thereby improving the flatness and uniformity of the copper plating layer, enhancing the appearance quality and electrical performance of the PCB board. Filtering the electroplating solution removes harmful substances such as impurity particles and anode sludge in it, preventing them from adhering to the surface of the PCB board or affecting the normal progress of the electroplating reaction. Re-adding the filtered electroplating solution to continue electroplating can provide a pure environment for the electroplating process, making the deposition of copper ions more pure and dense, further improving the quality and performance of the copper plating layer. Further, by vibrating the anode material and adding a micro-etching agent to dissolve the anode sludge, it helps to maintain the activity and uniform dissolution of the anode, enabling the anode to stably supply copper ions. So that the supply of copper ions during the electroplating process is more stable, which is beneficial to maintaining the consistency of the electroplating reaction and ensuring the stability of the quality of the electroplating layer of the PCB board.

[0035] In addition, in one embodiment, referring to Figure 2 , in Figure 1Before step S11 of the illustrated embodiment, the following steps are also included but not limited to: Step S21, determining the type of chemical solution, the thickness of the copper foil layer of the PCB board, and the copper plating time of the PCB board; Step S22, removing the oil stain and metal oxide layer on the surface of the PCB board, and cleaning the PCB board with pure water; Step S23, determining the surface requirements of the PCB board, and determining the protection method of the PCB board according to the surface requirements; Step S24, contacting the surface of the PCB board with the chemical solution, and performing high-temperature treatment; Step S25, performing acid pickling on the PCB board.

[0036] It should be noted that during the pretreatment process of the PCB board, preparatory work is first carried out, such as determining the thickness of the copper foil layer of the PCB board, selecting a suitable chemical solution during the copper electroplating process of the PCB board, and determining the copper plating time of the PCB board. The cleaning process of the PCB board is carried out, and the oil stain and metal oxide layer on the surface of the PCB board are removed by acid pickling or alkali washing, and then it is cleaned with pure water to ensure that the surface of the PCB board is free of stains. The protection process of the PCB board is carried out, and according to different surface requirements, a covering or masking protection method is selected to prevent the surface of the PCB board from being polluted again; the pre-soaking treatment of the PCB board is carried out, the copper foil surface of the PCB board is contacted with the chemical solution, and the treatment is carried out under the condition of increasing the temperature to ensure that the subsequent copper plating effect of the PCB board is more ideal. The acid pickling of the PCB board is carried out to remove the surface oxide and activate the surface. In this embodiment, a sulfuric acid solution with a concentration of 5% - 10% is used to perform acid pickling on the PCB board, and the acid pickling time should not be too long to prevent excessive oxidation of the surface.

[0037] In addition, in one embodiment, referring to Figure 3 , in Figure 1 Before step S13 of the illustrated embodiment, the following steps are also included but not limited to: Step S31, confirming the first current density in the electroplating tank; Step S32, when the first current density is reduced to the preset current density range, performing low-current electrolysis on the anode mud on the surface of the anode material to make the anode mud detach from the surface of the anode material.

[0038] It should be noted that the first current density represents the real-time current density in the electroplating solution.

[0039] It should be noted that when continuously electroplating copper on the PCB board, the anode sludge in the electroplating solution will continuously accumulate. Therefore, it is necessary to cut off the power supply of the electroplating tank and adjust the current density of the electroplating solution. By adjusting the current control device of the electroplating equipment, gradually reduce the first current density of the electroplating solution until the first current density is reduced to a preset current density range. When the first current density is reduced to the preset current density range, perform low-current electrolysis on the anode sludge on the surface of the anode material. The process of low-current electrolysis is relatively gentle and will not cause excessive damage to the electroplating equipment and the anode material, so that the anode sludge on the surface of the anode material gradually loosens, thereby improving the copper electroplating reaction rate of the PCB board and optimizing the electroplating efficiency. In addition, no harmful waste gas and waste water will be generated additionally during the low-current electrolysis process. At the same time, due to the reduction of the current density, the energy consumption during the electroplating process can also be reduced.

[0040] It should be noted that in this embodiment, the first current density of the electroplating solution can also be adjusted by adjusting the voltage input to the electroplating solution; or, adjusting the distance between the anode material and the cathode material to adjust the first current density, increasing the relative distance between the anode material and the cathode material to reduce the first current density of the electroplating solution; or, within the allowable range of conditions, reducing the temperature of the electroplating solution to further reduce the first current density.

[0041] It should be noted that in this embodiment, during the copper electroplating process of the PCB board, an intermittent electroplating form is adopted, that is, the current is periodically turned on and off, and the current density of the electroplating solution is flexibly adjusted by adjusting the time ratio of the current on and off.

[0042] The current density range is 0.2 ASD to 0.5 ASD. It should be noted that the current density of the electroplating tank is reduced to 0.2 - 0.5 ASD, and low-current electrolysis is carried out for 2 - 3 hours to gradually loosen the anode sludge. Within the current density range of 0.2 ASD to 0.5 ASD, low-current electrolysis can act on the anode sludge gently and effectively, weakening its binding force with the surface of the anode material, so that it is easier to fall off from the surface of the anode material. This removal method is more delicate than mechanical scraping or high-current impact, and can reduce the damage to the surface of the anode material. Due to the moderate current density, it will not cause excessive electrochemical corrosion or damage to the surface of the anode material.

[0043] In addition, in one embodiment, referring to Figure 4 , after Figure 1 the step S14 of the embodiment shown, it further includes but is not limited to the following steps: Step S41, adding hydrogen peroxide to the electroplating solution and heating the electroplating solution; Step S42, when the electroplating solution is heated to the first preset temperature, perform the first air stirring on the electroplating solution; Step S43: After the electroplating solution is aerated and stirred for a first preset duration, filter the electroplating solution.

[0044] It should be noted that after adding a micro-etching agent to the electroplating solution to gradually dissolve the anodic sludge on the surface of the anode material, add hydrogen peroxide to the electroplating solution and heat-treat the electroplating solution. Hydrogen peroxide can react with copper ions or other components in the electroplating solution to slightly etch the surface of the PCB board, increasing the roughness of the copper foil layer surface of the PCB board, thereby improving the adhesion between the copper foil layer and the PCB board and enhancing the stability and reliability of the copper foil layer. Heating the electroplating solution can effectively increase the diffusion rate of ions in the electroplating solution, thereby accelerating the copper electroplating rate of the PCB board. At the same time, an appropriate temperature increase helps the uniform distribution and stability of each component in the electroplating solution, shortening the copper electroplating cycle of the PCB board.

[0045] It should be noted that the first preset temperature is 65 °C, and the first preset duration is 2 to 4 hours. In this embodiment, when the electroplating solution is heated to the first preset temperature, the electroplating solution is kept warm and stirred for the first preset duration. Setting the first preset temperature to 65 °C can promote the oxidation reaction of hydrogen peroxide and will not cause the components in the electroplating solution to decompose or deteriorate due to too high a temperature. It can not only accelerate the oxidation of impurities but also ensure the stability of the electroplating solution. Setting the first preset duration to 2 to 4 hours ensures that the electroplating solution has enough time to be fully stirred and react at a constant temperature. The first air stirring not only increases the fluidity of the electroplating solution but also helps hydrogen peroxide to be evenly distributed in the electroplating solution, thereby more effectively contacting and reacting with the impurities in the electroplating solution.

[0046] Exemplarily, add an appropriate amount of micro-etching agent, such as copper sulfate solution, to the electroplating tank to gradually dissolve the anodic sludge on the surface of the anode material. Add 1 - 3 ml / L of hydrogen peroxide with a concentration of 30%, start heating, and when the temperature of the electroplating solution rises to about 65 °C (the first preset temperature), turn on the air stirring and keep the air stirring for 2 - 4 hours (the first preset duration) to enable hydrogen peroxide to oxidize some organic impurities and reduced metal ions in the electroplating solution, and at the same time, it also helps to remove the anodic sludge.

[0047] In addition, in one embodiment, referring to Figure 5 , in Figure 4 the step S53 of the illustrated embodiment, it further includes but is not limited to the following steps: Step S51: Stop the first air stirring and pour the adsorption material into the electroplating solution; Step S52: After the adsorption material is completely dissolved in the electroplating solution, perform second air stirring on the electroplating solution, and control the electroplating solution to be in a heat-preserved state until the second air stirring reaches a second preset duration; Step S53: Turn off the second air agitation, and heat up the electroplating solution to precipitate the adsorption material. Step S54: After the temperature of the electroplating solution drops to the second preset temperature, place the PP filter element into the electroplating solution to filter the electroplating solution.

[0048] It should be noted that the adsorption materials in this embodiment include, but are not limited to, materials with adsorption functions such as activated carbon or nanomaterials. There is no specific limitation in this embodiment. The second preset duration is 2 to 4 hours, and the second preset temperature is 0°C.

[0049] It should be noted that before pouring the adsorption material into the electroplating solution, ultrasonic treatment or chemical modification is performed on the adsorption material to enhance the adsorption property of the adsorption material. It should be noted that between the first air agitation and the second air agitation, there is also a stage of standing still for the electroplating solution. Through the standing still stage, the impurities in the electroplating solution are fully precipitated or aggregated, and then the second agitation is carried out to improve the agitation efficiency.

[0050] Exemplarily, in this embodiment, when the second agitation is performed on the electroplating solution, after the activated carbon powder is dissolved, the bath solution needs to be fully agitated to ensure that the activated carbon powder is evenly dispersed in the electroplating solution and can fully adsorb the impurities and suspended matters in the electroplating solution. Perform heat preservation agitation on the electroplating solution, and perform heat preservation agitation according to the specified time and temperature. The heat preservation time is 2 to 4 hours (the second preset duration), and the temperature is controlled at about 65°C to improve the adsorption effect of the activated carbon. Precipitate and filter the impurities, turn off the air agitation, heat up to let the activated carbon powder slowly precipitate to the bottom of the tank. When the temperature drops to about 0°C (the second preset temperature), filter the bath solution with a 10um PP filter element plus filter aid powder into a clean working tank to remove the activated carbon powder and impurities in the bath solution. Regularly detect the composition of the bath solution. After the activated carbon treatment, it is necessary to regularly detect the composition and concentration of the bath solution to ensure that it meets the process requirements. If residual impurities or other abnormal conditions are found in the bath solution, they should be processed in time.

[0051] Add according to the specified dosage and ratio. When adding the micro-etching agent, it should be strictly operated according to the specified dosage and ratio to avoid overdose or underdose. Excessive micro-etching agent may cause excessive corrosion and affect the electroplating quality, while insufficient micro-etching agent may not achieve the expected effect. Control the micro-etching time. Too long micro-etching time will lead to excessive micro-etching and affect the electroplating effect. The micro-etching time should be strictly controlled according to the process requirements, generally between 20 - 40 seconds. Control the bath solution temperature. The bath solution temperature has a great influence on the micro-etching rate. Too high temperature will accelerate the micro-etching rate and easily lead to excessive micro-etching. The bath solution temperature should be controlled at about 30°C. Control the agitation speed. Appropriate agitation can ensure the uniform distribution of the micro-etching agent and avoid local overdose. The agitation speed should be adjusted according to the volume of the bath solution and the properties of the micro-etching agent.

[0052] In addition, in one embodiment, referring to Figure 6 , after step S13 of the embodiment shown in Figure 1 , the following steps are included but not limited to: Step S61, after metal particles precipitate on the surface of the anode material, confirm whether the metal particles are suspended on the surface layer of the electroplating solution. When the metal particles are suspended on the surface layer of the electroplating solution, determine that the metal particles are anode sludge particles; Step S62, alternatively, confirm whether there are copper grains on the surface of the copper foil layer. When the copper grains on the surface of the copper foil layer decrease or disappear, determine that the anode sludge has become loose; Step S63, alternatively, take a sample of the electroplating solution to obtain the copper ion concentration in the electroplating solution. When the copper ion concentration is lower than the first preset concentration, determine that the anode sludge has become loose.

[0053] It should be noted that by observing the changes in the electroplating tank, after reducing the current density, the looseness of the anode sludge is judged by observing the situation in the electroplating tank. If the anode sludge begins to loosen, some small particles will fall off the surface of the anode material and suspend in the electroplating solution, making the electroplating solution turbid. By observing the metal particles on the surface layer of the electroplating solution, the staff can timely discover possible problems in the electroplating process, such as uneven electroplating solution composition, inappropriate electroplating conditions, etc. Check the electroplating quality. After the anode sludge becomes loose, the electroplating quality may be affected. By checking the PCB board after electroplating, observe whether the copper grains on the surface of the copper foil layer decrease or disappear. If the situation of the copper grains improves, it indicates that the anode sludge may have become loose. Regular sampling and analysis. Regularly take samples from the electroplating tank and detect the changes in the copper ion concentration and other components in the electroplating solution through chemical analysis methods. When the copper ion concentration decreases, it indicates that the anode sludge may have started to dissolve or become loose.

[0054] The thickness of the copper foil layer is 5 μm to 0.8 μm. It should be noted that within this thickness range, the copper foil can carry a larger current. A thicker copper foil has a smaller resistance. According to the current thermal effect formula (Q = I²Rt), when passing the same current, less heat is generated on the copper foil, thus effectively preventing the circuit from being damaged due to overheating.

[0055] The copper foil thickness affects the impedance of the circuit. According to the transmission line theory, the characteristic impedance is related to factors such as copper foil thickness, line width, and dielectric thickness. Within this thickness range, an appropriate copper foil thickness can ensure the integrity of the signal during transmission, reducing signal reflection and attenuation. The thickness range of 5 μm to 0.8 μm provides sufficient flexibility to meet the requirements of different application scenarios. A thinner copper foil (such as 0.8 μm) is suitable for electronic devices with strict requirements on weight and volume, while a thicker copper foil (such as 5 μm) is more suitable for occasions with higher requirements on current-carrying capacity and mechanical strength. In addition, in one embodiment, referring to Figure 7 , in Figure 1 step S13 of the embodiment shown, it further includes but is not limited to the following steps: Step S71, using a metal rod to strike the anode material, wherein the metal stability of the metal rod is greater than that of the anode material.

[0056] It should be noted that by striking the anode material, minute deformations can be generated on its surface, thereby increasing its contact area with the electroplating solution. Since the stability of the metal rod is greater than that of the anode material, impurities are not easily introduced or the electroplating solution is not contaminated during the striking process, thus ensuring the uniformity of electroplating. Striking the anode material can also promote the uniform dissolution of the active substances on the surface of the anode material and reduce the generation of anode sludge. During the electroplating process, striking the anode material can also be used as a means to adjust the parameters of the electroplating method. By observing the changes on the surface of the anode material and the quality of the electroplating layer after striking, the parameters such as the composition of the electroplating solution, current density, and temperature can be optimized and adjusted.

[0057] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the above-mentioned embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A method for copper electroplating of a PCB board, characterized in that, Applied to an electroplating bath, an anode material, a cathode material and a titanium basket are placed in the electroplating bath. The anode material is placed inside the titanium basket. An electroplating solution is put into the electroplating bath, and the electroplating solution submerges the anode material, the cathode material and the titanium basket. The method includes: Immerse the PCB board into the electroplating bath for copper plating, and precipitate copper ions in the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board; Stop the electroplating operation when copper grains are detected on the thickened copper surface of the PCB board; Reduce the current density in the electroplating bath. After reduction, electrolyze for a preset duration, vibrate the anode material until the anode material is saturated and does not decrease. Add a micro-etching agent into the electroplating bath to dissolve the anode sludge of the anode material; Take out the electroplating solution from the electroplating bath and filter it, and filter the electroplating solution and then put it back into the electroplating bath; After completing the filtration treatment of the electroplating solution, add the electroplating solution back into the electroplating bath and continue the electroplating treatment of the PCB board.

2. The PCB board copper electroplating method according to claim 1, characterized in that Before immersing the PCB board into the electroplating bath for copper plating, the method further includes: Determine the type of chemical solution, the copper foil layer thickness of the PCB board and the copper plating time of the PCB board; Remove the oil stain and metal oxide layer on the surface of the PCB board, and clean the PCB board with pure water; Determine the surface requirements of the PCB board, and determine the protection method of the PCB board according to the surface requirements; Contact the surface of the PCB board with the chemical solution and perform high-temperature treatment; Perform acid leaching on the PCB board.

3. The PCB board copper electroplating method according to claim 1, characterized in that, Before vibrating the anode material, the method further includes: Confirm the first current density in the electroplating bath; When the first current density is reduced to a preset current density range, perform low-current electrolysis on the anode sludge on the surface of the anode material to make the anode sludge detach from the surface of the anode material.

4. The PCB board copper electroplating method according to claim 3, characterized in that, The current density range is 0.2 ASD to 0.5 ASD.

5. The PCB board copper electroplating method according to claim 1, wherein After adding the micro-etching agent into the electroplating bath to dissolve the anode sludge, it further includes: Add hydrogen peroxide into the electroplating solution and heat the electroplating solution; When the electroplating solution is heated to a first preset temperature, perform first air stirring on the electroplating solution; When the air stirring of the electroplating solution reaches a first preset duration, filter the electroplating solution.

6. The PCB board copper electroplating method according to claim 5, characterized in that, The filtering of the electroplating solution includes: Stop the first air stirring, and pour the adsorption material into the electroplating solution; When the adsorption material is completely dissolved in the electroplating solution, perform second air stirring on the electroplating solution, and control the electroplating solution to be in a heat preservation state until the second air stirring reaches a second preset duration; Turn off the second air stirring, and raise the temperature of the electroplating solution to precipitate the adsorption material; When the temperature of the electroplating solution drops to a second preset temperature, put a PP filter element into the electroplating solution to filter the electroplating solution.

7. The PCB board copper electroplating method according to claim 5, wherein, The temperature of the electroplating solution is controlled between 20°C and 40°C, and the etching time of the micro-etchant is from twenty seconds to forty seconds.

8. The PCB board copper electroplating method according to claim 1, characterized in that, After subjecting the anode material to vibration treatment, the method further includes: When metal particles are deposited on the surface of the anode material, it is confirmed whether the metal particles are suspended on the surface layer of the electroplating solution. When the metal particles are suspended on the surface layer of the electroplating solution, it is determined that the metal particles are anode sludge particles; Alternatively, it is confirmed whether there are copper particles on the surface of the copper foil layer. When the copper particles on the surface of the copper foil layer decrease or disappear, it is determined that the anode sludge becomes loose; Alternatively, a sample of the electroplating solution is taken to obtain the copper ion concentration in the electroplating solution. When the copper ion concentration is lower than the first preset concentration, it is determined that the anode sludge becomes loose.

9. The PCB board copper electroplating method according to claim 2, characterized in that, The thickness of the copper foil layer is from 5μm to 0.8μm.

10. The PCB board copper electroplating method according to claim 1, wherein Subjecting the anode material to vibration treatment includes: Using a metal rod to strike the anode material, wherein the metal stability of the metal rod is greater than that of the anode material.

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