A PCB copper electroplating method

Abstract

The present invention provides a copper electroplating method for printed circuit boards (PCBs), comprising immersing the PCB in an electroplating bath for copper plating, depositing copper ions from an anode material onto the copper surface of the PCB to thicken the copper surface; stopping the electroplating operation if copper particles are detected on the thickened copper surface of the PCB; reducing the current density in the electroplating bath, performing electrolysis for a predetermined period of time after the reduction, vibrating the anode material until the anode material is saturated and no further decrease is observed, adding a micro-etching agent to the electroplating bath to dissolve the anode slime; removing the electroplating solution from the electroplating bath and filtering it, then re-filtering the electroplating solution and returning it to the electroplating bath; and, after the electroplating solution is filtered, re-adding the electroplating solution to the electroplating bath to continue electroplating the PCB. The technical solution of this embodiment enables a worker to visually confirm the degree of anode slime deposition in the electroplating bath, thereby improving the uniformity of current distribution within the bath.

Description

Technical Field

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

[0002] Currently, copper electroplating methods for PCBs typically involve immersing the PCB in a plating tank filled with a chemical solution. The copper is then electroplated using anode and cathode materials within the plating tank. After copper plating, copper particles form on the copper foil layer of the PCB, and anode slime forms on the surface of the anode material. This anode slime is then adsorbed by an anode bag. Existing methods for treating anode slime typically involve removing the anode bag from the plating tank to prevent excessive slime accumulation. However, since the anode bag is typically located at the bottom of the plating tank, workers are unable to effectively determine the extent of slime accumulation within the bag. This can lead to blockage or excessive slime accumulation within the bag, resulting in uneven current distribution within the plating tank and potential safety hazards such as localized overheating or electric shock. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for copper electroplating on printed circuit boards (PCBs) that enables a worker to visually confirm the deposition level of anode mud in the electroplating tank and improves the uniformity of current distribution within the electroplating tank.

[0004] In a first aspect, an embodiment of the present invention provides a method for copper electroplating on a PCB, which is applied to an electroplating pool, wherein an anode material, a cathode material, and a titanium basket are placed in the electroplating pool, the anode material is placed inside the titanium basket, and an electroplating solution is placed in the electroplating pool, wherein the electroplating solution immerses the anode material, the cathode material, and the titanium basket. The method comprises:

[0005] Immersing the PCB board in an electroplating tank for copper plating, and depositing copper ions in the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board;

[0006] When copper particles are detected on the copper surface of the thickened PCB board, the electroplating operation is stopped;

[0007] reducing the current density in the electroplating tank, electrolyzing for a preset time after the reduction, vibrating the anode material until the anode material is saturated and does not decrease, adding a micro-etching agent into the electroplating tank to dissolve the anode mud;

[0008] Taking out the electroplating solution from the electroplating tank and filtering it, filtering the electroplating solution and putting it back into the electroplating tank;

[0009] After the electroplating solution is filtered, the electroplating solution is added back into the electroplating tank to continue electroplating the PCB.

[0010] In some embodiments of the present invention, before immersing the PCB board in the electroplating tank for copper plating, the method further includes:

[0011] 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;

[0012] Removing oil stains and metal oxide layers from the surface of the PCB board, and cleaning the PCB board with pure water;

[0013] Determining board surface requirements of the PCB board, and determining a protection method for the PCB board according to the board surface requirements;

[0014] contacting the surface of the copper foil layer with the chemical solution and performing high temperature treatment;

[0015] The PCB board is acid-dipped.

[0016] In some embodiments of the present invention, before performing vibration treatment on the anode material, the method further comprises:

[0017] determining a first current density in the electroplating bath;

[0018] When the first current density decreases to a preset current density range, the anode mud on the surface of the anode material is subjected to low current electrolysis to separate the anode mud from the surface of the anode material.

[0019] In some embodiments of the present invention, the current density range is 0.2 ASD to 0.5 ASD.

[0020] In some embodiments of the present invention, after adding a micro-etching agent into the electroplating tank to dissolve the anode mud, the method further comprises:

[0021] adding hydrogen peroxide to the electroplating solution and heating the electroplating solution;

[0022] When the electroplating solution is heated to a first preset temperature, performing a first air stirring on the electroplating solution;

[0023] After the electroplating liquid is subjected to the air stirring for a first preset time, the electroplating liquid is filtered.

[0024] In some embodiments of the present invention, filtering the electroplating solution includes:

[0025] stopping the first air stirring and pouring the adsorption material into the electroplating solution;

[0026] After the adsorption material is completely dissolved in the electroplating solution, the electroplating solution is subjected to a second air stirring, and the electroplating solution is controlled to be in a heat preservation state until the second air stirring reaches a second preset time length;

[0027] turning off the second air stirring and heating the electroplating solution to precipitate the adsorption material;

[0028] When the temperature of the electroplating solution is lowered to a second preset temperature, a PP filter element is placed into the electroplating solution to filter the electroplating solution.

[0029] In some embodiments of the present invention, the temperature of the electroplating solution is controlled between 20° C. and 40° C., and the micro-etching time of the micro-etching agent is between 20 seconds and 40 seconds.

[0030] In some embodiments of the present invention, after vibrating the anode material, the method further comprises:

[0031] After metal particles are precipitated on the surface of the anode material, confirming whether the metal particles are suspended in the surface layer of the electroplating solution, and determining that the metal particles are anode mud particles when the metal particles are suspended in the surface layer of the electroplating solution;

[0032] Alternatively, confirming whether copper particles exist on the surface of the copper foil layer, and determining that the anode mud is loose when the copper particles on the surface of the copper foil layer decrease or disappear;

[0033] Alternatively, the electroplating solution is sampled to obtain the copper ion concentration in the electroplating solution, and when the copper ion concentration is lower than a first preset concentration, it is determined that the anode mud is loose.

[0034] In some embodiments of the present invention, the copper foil layer has a thickness of 5 μm to 0.8 μm.

[0035] In some embodiments of the present invention, the vibrating treatment of the anode material comprises:

[0036] The anode material is struck with a metal rod, wherein the metal stability of the metal rod is greater than that of the anode material.

[0037] The copper electroplating method for a PCB according to an embodiment of the present invention has at least the following beneficial effects:

[0038] The PCB is immersed in an electroplating tank for copper plating, and copper ions in the anode material are deposited onto the copper surface of the PCB to thicken the copper surface of the PCB. If copper particles are detected on the thickened copper surface of the PCB, the electroplating operation is stopped. The current density in the electroplating tank is reduced, and after the current density is reduced, the electrolysis is continued for a preset time, and the anode material is vibrated until the anode material is saturated and does not decrease. A micro-etchant is added to the electroplating tank to dissolve the anode mud. The electroplating solution is removed from the electroplating tank and filtered, and then the filtered electroplating solution is returned to the electroplating tank. After the electroplating solution is filtered, the electroplating solution is returned to the electroplating tank and the electroplating process on the PCB is continued. According to the technical solution of this embodiment, the staff can visually confirm the deposition level of anode mud in the electroplating tank, thereby improving the uniformity of current distribution in the electroplating tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a flow chart of a copper electroplating method for a PCB provided by one embodiment of the present invention;

[0040] Figure 2 This is a flow chart of performing pre-processing operations on a PCB board according to an embodiment of the present invention;

[0041] Figure 3 This is a flow chart of tapping the anode material provided by one embodiment of the present invention until the anode material is filled to saturation and does not decrease;

[0042] Figure 4 This is a flow chart of adding a micro-etching agent into an electroplating tank to dissolve anode mud, according to one embodiment of the present invention;

[0043] Figure 5 This is a flow chart of filtering an electroplating solution provided by one embodiment of the present invention;

[0044] Figure 6 A flow chart for determining whether anode mud on the surface of an anode material is loosened is provided in one embodiment of the present invention;

[0045] Figure 7 This is a flow chart of tapping anode materials provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0046] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0047] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0048] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0049] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0050] An embodiment of the present invention provides a copper electroplating method for a printed circuit board (PCB), which is applied to an electroplating cell. An anode material, a cathode material, and a titanium basket are placed in the electroplating cell, the anode material being placed inside the titanium basket. An electroplating solution is placed in the electroplating cell, and the electroplating solution immerses the anode material, the cathode material, and the titanium basket. The method comprises: immersing the PCB in the electroplating tank for copper plating, and depositing copper ions in the anode material onto the copper surface of the PCB to thicken the copper surface of the PCB; stopping the electroplating operation when copper particles are detected on the thickened copper surface of the PCB; reducing the current density in the electroplating cell, electrolyzing for a preset time after the reduction, vibrating the anode material until the anode material is saturated and does not decrease, adding a micro-etching agent to the electroplating cell to dissolve anode mud of the anode material; removing the electroplating solution from the electroplating cell and filtering it, filtering the electroplating solution, and re-introducing it into the electroplating cell; and after the electroplating solution is filtered, re-adding the electroplating solution to the electroplating cell to continue electroplating the PCB. According to the technical solution of this embodiment, the staff can visually confirm the deposition degree of anode mud in the electroplating tank, thereby improving the uniformity of current distribution in the electroplating tank.

[0051] It should be noted that during the copper electroplating process on PCBs, the anode material gradually dissolves, and the resulting anode mud is deposited in the plating tank, particularly on the surface of the anode material. Vibrating the anode material can be used to determine whether the anode mud on the surface has loosened. When the anode mud begins to loosen, fine particles will fall off the surface of the anode material and become suspended in the plating solution, causing the plating solution to become turbid. By observing the fine particles on the surface of the plating solution, staff can visually confirm the degree of anode mud deposition in the plating tank and improve the uniformity of current distribution within the plating tank.

[0052] The control method of the embodiment of the present invention is further described below based on the accompanying drawings.

[0053] Reference Figure 1 , Figure 1 A flowchart of a PCB copper electroplating method provided in an embodiment of the present invention includes but is not limited to the following steps:

[0054] Step S11, immersing the PCB board in an electroplating tank for copper plating, and depositing copper ions in the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board;

[0055] It should be noted that thickening the copper surface can reduce the resistance to current transmission and lower the resistance of the line, thereby reducing energy loss during signal transmission and improving the efficiency and speed of signal transmission to ensure high-performance operation of electronic equipment.

[0056] It should be noted that during copper electroplating on PCBs, a layer of insoluble or poorly soluble material (i.e., anode slime) forms on the surface of the anode material due to electrochemical reactions. Since the plating solution in the electroplating tank is typically dark in color, it is difficult for personnel to visually assess the extent of anode slime accumulation. Therefore, in this embodiment, the anode material is placed within a titanium basket, which limits its position and range of movement within the electroplating tank. As those skilled in the art will appreciate, since the electroplating tank is typically equipped with artificial waves during copper electroplating to continuously flush the PCB with plating solution, personnel can visually observe whether anode slime has formed on the surface of the anode material.

[0057] 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, which can provide sufficient copper ions for the PCB board to use in the electroplating process, and effectively ensure a 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.

[0058] For example, the anode material in this embodiment can also use phosphor copper balls as electroplating anode materials. When the PCB board is electroplated, a black phosphorus film will form on the surface of the phosphor copper balls. The phosphorus film has good metallic conductivity and can effectively control the electroplating speed to improve the corrosion resistance of the copper foil layer on the surface of the PCB board, and can effectively reduce the generation of anode mud, thereby improving the quality and performance of the coating.

[0059] Step S12, when copper particles are detected on the copper surface of the thickened PCB board, stopping the electroplating operation;

[0060] It's important to note that the presence of copper particles can cause an uneven surface on the PCB. In subsequent processes, such as lamination and photolithography, this uneven surface can lead to uneven adhesion of the film or photoresist, affecting pattern transfer accuracy and even causing problems like shorts or opens. Promptly stopping the electroplating process can effectively prevent these issues and avoid a large number of defective products in subsequent processes. During the electroplating process, copper ions are continuously deposited onto the copper surface of the PCB under the influence of an electric field. If copper particles already appear on the copper surface of an already thickened PCB, continuing electroplating may cause them to grow further. Stopping the electroplating process prevents further copper ion deposition on the copper particles, preventing them from further deteriorating the performance and quality of the PCB.

[0061] Step S13, reducing the current density in the electroplating tank, electrolyzing for a preset time after the 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 mud of the anode material;

[0062] It's important to note that lowering the current density can make the electrochemical reaction during the electroplating process more uniform and stable. This helps reduce variations in copper ion deposition rates on the cathode (PCB) surface, preventing localized over-thickness or under-thickness of the copper plating, thereby improving the uniformity and consistency of the copper plating layer and enhancing the overall quality of the PCB. At lower current densities, reactions on the electrode surface are more controllable, reducing side reactions such as hydrogen evolution. Reducing side reactions not only prevents defects such as pores and pitting on the PCB surface, but also improves electroplating efficiency and reduces energy consumption. Vibrating the anode material breaks down the diffusion layer formed on the anode surface, allowing the solution to flow more evenly around the anode. This promotes uniform dissolution of the anode material, avoiding localized passivation or uneven dissolution on the anode surface, ensuring a continuous and stable supply of copper ions, and maintaining the stability of the electroplating process. Vibration can also promptly remove any anode slime from the anode surface, preventing its accumulation. Anode slime accumulation can hinder normal anode dissolution and affect the electroplating effect. Vibration treatment can make the anode mud more easily dispersed in the electroplating solution, making it easier to handle later. It can also reduce the anode passivation caused by the accumulation of anode mud and extend the service life of the anode.

[0063] Furthermore, when the anode mud on the surface of the anode material falls off into the electroplating solution, the anode mud is dissolved by adding a micro-etching agent, 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 by the micro-etching agent helps to reduce energy consumption and environmental pollution in the electroplating process, thereby maintaining the stability of the electrolyte, extending the service life of the electroplating tank and improving the electroplating efficiency.

[0064] It should be noted that the microetching agent used in this embodiment includes but is not limited to copper sulfate solution.

[0065] Step S14, taking the electroplating solution out of the electroplating tank and filtering it, filtering the electroplating solution and putting it back into the electroplating tank;

[0066] It should be noted that during the electroplating process, various impurity particles may enter the plating solution, such as anode mud from anode dissolution, airborne dust, and metal debris from equipment wear. If these impurity particles remain in the plating solution, they may adhere to the PCB surface, causing defects such as particles and pitting, which in turn affect the appearance and performance of the PCB. Filtration can effectively remove these impurity particles, improving the surface quality of the PCB. However, if impurity particles accumulate in the plating solution, they may clog the piping, nozzles, and other components of the electroplating equipment, affecting proper circulation and spraying of the plating solution and resulting in uneven plating. Filtration can prevent equipment clogging caused by impurity particles, ensuring proper operation and maintaining stable plating process conditions. Furthermore, the presence of impurities may trigger side reactions that deplete the active ingredients in the plating solution, thereby reducing its performance and service life. Removing impurities from the plating solution through filtration can reduce the occurrence of side reactions, stabilize the chemical composition of the plating solution, and thus extend the service life of the plating solution and reduce production costs.

[0067] It is understandable that the electroplating solution after filtration is purer and its properties such as conductivity are more stable, which is conducive to improving the deposition efficiency of copper ions on the surface of PCB boards, making the electroplating process more efficient, shortening the electroplating time, and improving production efficiency.

[0068] Step S15: After the electroplating solution is filtered, the electroplating solution is added back into the electroplating tank to continue electroplating the PCB.

[0069] It should be noted that by reducing the current density, presetting the electrolysis duration, vibrating the anode material, and adding a micro-etchant, electroplating conditions are improved in multiple ways. This facilitates more uniform copper ion deposition on the PCB during subsequent electroplating, reduces the generation of new copper particles, and thus improves the flatness and uniformity of the copper-plated layer, enhancing the appearance quality and electrical performance of the PCB. Filtering the electroplating solution removes impurities, anode mud, and other harmful substances, preventing them from adhering to the PCB surface and affecting the normal electroplating reaction. Re-adding the filtered electroplating solution to continue electroplating provides a pure environment for the electroplating process, ensuring a purer and denser copper ion deposition, further improving the quality and performance of the copper-plated layer. Furthermore, vibrating the anode material and adding a micro-etchant to dissolve the anode mud help maintain anode activity and uniform dissolution, ensuring a stable supply of copper ions. This ensures a more stable supply of copper ions during the electroplating process, which helps maintain a consistent electroplating reaction and ensures the stability of the electroplated layer quality on the PCB.

[0070] In addition, in one embodiment, referring to Figure 2 ,exist Figure 1Before step S11 of the illustrated embodiment, the following steps are also included but not limited to:

[0071] 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;

[0072] Step S22, removing the oil stains and metal oxide layer on the surface of the PCB board, and cleaning the PCB board with pure water;

[0073] Step S23, determining the surface requirements of the PCB board, and determining the protection method of the PCB board according to the surface requirements;

[0074] Step S24, contacting the surface of the PCB with the chemical solution and performing high temperature treatment;

[0075] Step S25: acid-immersing the PCB.

[0076] It should be noted that during the PCB pretreatment process, preparations are first performed to determine the thickness of the copper foil layer, select the appropriate chemical solution for the copper electroplating process, and determine the copper plating time. The PCB is then cleaned using an acid or alkaline wash to remove oil and metal oxide layers from the surface. It is then rinsed with pure water to ensure a stain-free surface. The PCB is then protected using either a blanket or masking method, depending on the surface requirements, to prevent further contamination. The PCB is then pre-impregnated, exposing the copper foil surface to a chemical solution at elevated temperatures to ensure optimal copper plating results. The PCB is then acid-impregnated to remove surface oxides and activate the surface. In this embodiment, a 5% to 10% sulfuric acid solution is used for the acid immersion, and the immersion time should be kept short to prevent excessive oxidation.

[0077] In addition, in one embodiment, referring to Figure 3 ,exist Figure 1 Before step S13 in the illustrated embodiment, the following steps are also included but not limited to:

[0078] Step S31, confirming a first current density in the electroplating tank;

[0079] Step S32: When the first current density is reduced to a preset current density range, low-current electrolysis is performed on the anode mud on the surface of the anode material to separate the anode mud from the surface of the anode material.

[0080] It should be noted that the first current density represents the real-time current density in the electroplating solution.

[0081] It should be noted that during continuous copper electroplating of PCBs, anode mud in the electroplating solution will continue to accumulate. Therefore, it is necessary to disconnect the power to the electroplating tank and adjust the current density of the electroplating solution. By adjusting the current control device of the electroplating equipment, the first current density of the electroplating solution is gradually reduced until the first current density drops to a preset current density range. After the first current density drops to the preset current density range, the anode mud on the surface of the anode material is subjected to low-current electrolysis. This low-current electrolysis process is relatively gentle and does not cause excessive damage to the electroplating equipment or anode material. This gradually loosens the anode mud on the surface of the anode material, thereby increasing the copper electroplating reaction rate of the PCB board and optimizing the electroplating efficiency. Furthermore, the low-current electrolysis process does not generate any additional harmful waste gas or wastewater. Furthermore, the reduced current density also reduces energy consumption during the electroplating process.

[0082] It should be noted that, in this embodiment, the first current density of the plating solution can be adjusted by adjusting the voltage input to the plating solution; or, the first current density can be adjusted by adjusting the distance between the anode material and the cathode material, and the first current density of the plating solution can be reduced by increasing the relative distance between the anode material and the cathode material; or, within the scope permitted by conditions, the first current density can be reduced by lowering the temperature of the plating solution.

[0083] It should be noted that in the copper electroplating process on the PCB board in this embodiment, intermittent electroplating 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.

[0084] The current density range is 0.2 ASD to 0.5 ASD. It should be noted that reducing the current density in the electroplating tank to 0.2-0.5 ASD and performing low-current electrolysis for 2-3 hours gradually loosens the anode slime. Within this current density range, low-current electrolysis gently yet effectively acts on the anode slime, weakening its bond to the anode material surface and making it easier to remove. This removal method is more precise than mechanical scraping or high-current shocks, minimizing damage to the anode material surface. Due to the moderate current density, it does not cause excessive electrochemical corrosion or damage to the anode material surface.

[0085] In addition, in one embodiment, referring to Figure 4 ,exist Figure 1 After step S14 in the embodiment shown, the following steps are also included but not limited to:

[0086] Step S41, adding hydrogen peroxide to the electroplating solution to heat the electroplating solution;

[0087] Step S42, when the electroplating solution is heated to a first preset temperature, performing a first air stirring on the electroplating solution;

[0088] Step S43 , when the electroplating liquid is stirred by air for a first preset time, the electroplating liquid is filtered.

[0089] It should be noted that after adding a micro-etchant to the electroplating solution to gradually dissolve the anode mud on the surface of the anode material, hydrogen peroxide is added to the electroplating solution and the solution is heated. The hydrogen peroxide reacts with the copper ions and other components in the electroplating solution, slightly etching the surface of the PCB board, increasing the surface roughness of the copper foil layer 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, a moderate temperature increase helps to evenly distribute and stabilize the various components in the electroplating solution, shortening the copper electroplating cycle of the PCB board.

[0090] It should be noted that the first preset temperature is 65°C and the first preset time is 2 to 4 hours. In this embodiment, when the plating solution is heated to the first preset temperature, the plating solution is kept warm and stirred for the first preset time. Setting the first preset temperature to 65°C can promote the oxidation reaction of hydrogen peroxide without causing decomposition or deterioration of the components in the plating solution due to excessive temperature. This can both accelerate the oxidation of impurities and ensure the stability of the plating solution. Setting the first preset time to 2 to 4 hours ensures that the plating solution has sufficient time to be fully stirred and react at a constant temperature. The first air stirring not only increases the fluidity of the plating solution, but also helps the hydrogen peroxide to be evenly distributed in the plating solution, thereby more effectively contacting and reacting with impurities in the plating solution.

[0091] For example, an appropriate amount of micro-etching agent, such as copper sulfate solution, is added to the electroplating tank to gradually dissolve the anode mud on the surface of the anode material. 1-3 ml / L of 30% hydrogen peroxide is then added and heated. When the plating solution temperature reaches approximately 65°C (a first preset temperature), air agitation is initiated. The solution is then maintained under air agitation for 2-4 hours (a first preset duration) to allow the hydrogen peroxide to oxidize organic impurities and reduced metal ions in the plating solution, thereby facilitating the removal of the anode mud.

[0092] In addition, in one embodiment, referring to Figure 5 ,exist Figure 4 Step S53 in the illustrated embodiment also includes but is not limited to the following steps:

[0093] Step S51, stopping the first air stirring and pouring the adsorption material into the electroplating solution;

[0094] Step S52, after the adsorption material is completely dissolved in the electroplating solution, the electroplating solution is subjected to a second air stirring, and the electroplating solution is controlled to be in a heat preservation state until the second air stirring reaches a second preset time;

[0095] Step S53, turning off the second air stirring and heating the electroplating solution to precipitate the adsorption material;

[0096] In step S54 , when the temperature of the electroplating solution drops to a second preset temperature, the PP filter element is placed into the electroplating solution to filter the electroplating solution.

[0097] It should be noted that the adsorption materials in this embodiment include but are not limited to activated carbon or nanomaterials and other materials with adsorption properties. This embodiment does not make specific restrictions. The second preset time is 2 to 4 hours, and the second preset temperature is 0°C.

[0098] It should be noted that before the adsorption material is poured into the electroplating solution, the adsorption material is ultrasonically treated or chemically modified to enhance the adsorption of the adsorption material.

[0099] It should be noted that between the first air stirring and the second air stirring, there is a static stage for the electroplating liquid. The static stage allows the impurities in the electroplating liquid to fully precipitate or aggregate, and then the second stirring is performed to improve the stirring efficiency.

[0100] For example, in this embodiment, the plating solution undergoes a second stirring step. After the activated carbon powder dissolves, the bath solution needs to be thoroughly stirred to ensure that the activated carbon powder is evenly dispersed in the plating solution and can fully absorb impurities and suspended matter. The plating solution is then insulated and stirred for a specified time and temperature, ranging from 2 to 4 hours (a second preset time), with the temperature controlled at approximately 65°C to enhance the activated carbon's adsorption efficiency. Impurities are then precipitated and filtered. Air stirring is turned off, and the activated carbon powder is heated to allow it to slowly settle to the bottom of the bath. Once the temperature drops to approximately 0°C (a second preset temperature), the bath solution is filtered through a 10µm PP filter element with filter powder into a clean working tank to remove the activated carbon powder and impurities. Regular testing of the bath solution composition and concentration is required after the activated carbon treatment to ensure that it meets process requirements. Any residual impurities or other abnormalities in the bath solution should be addressed promptly.

[0101] When adding microetchants, strictly follow the prescribed dosage and ratio to avoid overdosing or underdosing. Excessive microetchant may cause excessive corrosion, affecting electroplating quality, while insufficient microetchant may not achieve the desired effect. Control the microetching time. Excessive microetching time can lead to excessive microetching, affecting the electroplating effect. The microetching time should be strictly controlled according to process requirements, generally between 20-40 seconds. Control the bath temperature, as it significantly affects the microetching rate. Excessive temperatures can accelerate the microetching rate and easily lead to excessive microetching. The bath temperature should be maintained at around 30°C. Control the stirring speed. Proper stirring ensures even distribution of the microetchant and avoids localized overdosing. The stirring speed should be adjusted according to the volume of the bath and the properties of the microetchant.

[0102] In addition, in one embodiment, referring to Figure 6 ,exist Figure 1 After step S13 in the embodiment shown, the following steps are also included but not limited to:

[0103] Step S61: After metal particles are precipitated on the surface of the anode material, it is determined whether the metal particles are suspended in the surface layer of the electroplating solution. If the metal particles are suspended in the surface layer of the electroplating solution, the metal particles are determined to be anode mud particles.

[0104] Step S62, alternatively, confirming whether copper particles exist 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 mud is loose.

[0105] Step S63, alternatively, sampling the electroplating solution to obtain the copper ion concentration in the electroplating solution. When the copper ion concentration is lower than a first preset concentration, it is determined that the anode mud is loose.

[0106] It's important to note that observing changes in the plating tank after reducing the current density can be used to determine if the anode slime is loosening. If the anode slime begins to loosen, small particles will fall off the surface of the anode material and become suspended in the plating solution, causing it to become turbid. Observing the metal particles on the surface of the plating solution allows staff to promptly identify potential problems during the electroplating process, such as uneven composition or inappropriate plating conditions. Checking the plating quality can also affect plating quality. Checking the PCB after plating can reduce or eliminate the copper particles on the copper foil surface. If this improves, the anode slime may be loosening. Regular sampling and analysis should be performed. Samples should be taken from the plating tank regularly and chemically analyzed to determine changes in the copper ion concentration and other components of the plating solution. A decrease in the copper ion concentration indicates that the anode slime may have begun to dissolve or loosen.

[0107] The thickness of the copper foil layer ranges from 5μm to 0.8μm. It's important to note that within this thickness range, copper foil can carry greater current. Thicker copper foil has lower resistance. According to the thermal effect of current equation (Q = I²Rt), when the same current flows through it, less heat is generated on the copper foil, effectively preventing damage to the circuit due to overheating.

[0108] The thickness of the copper foil will affect the impedance of the line. According to the transmission line theory, the characteristic impedance is related to factors such as the copper foil thickness, line width, and dielectric thickness. Within this thickness range, the appropriate copper foil thickness can ensure the integrity of the signal during transmission and reduce signal reflection and attenuation. The thickness range of 5μm to 0.8μm provides sufficient flexibility to meet the needs of different application scenarios. Thinner copper foil (such as 0.8μm) is suitable for electronic devices with strict requirements on weight and volume, while thicker copper foil (such as 5μm) is more suitable for occasions with higher requirements on current carrying capacity and mechanical strength.

[0109] In addition, in one embodiment, referring to Figure 7 ,exist Figure 1 Step S13 of the illustrated embodiment also includes but is not limited to the following steps:

[0110] In step S71 , the anode material is struck with a metal rod, wherein the metal stability of the metal rod is greater than that of the anode material.

[0111] It should be noted that by tapping the anode material, a slight deformation can be produced 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, it is not easy to introduce impurities or contaminate the electroplating solution during the tapping process, thereby ensuring the uniformity of the electroplating. Tapping 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 mud. During the electroplating process, tapping the anode material can also be used as a means of adjusting the parameters of the electroplating method. By observing the changes on the surface of the anode material after tapping and the quality of the electroplating layer, the parameters such as the electroplating solution composition, current density, and temperature can be optimized and adjusted.

[0112] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above implementation. Those skilled in the art can also make various equivalent modifications or substitutions under the shared conditions that do not violate the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A PCB copper electroplating method, characterized in that: Applied to an electroplating cell, wherein an anode material, a cathode material, and a titanium basket are placed in the electroplating cell, wherein the anode material is placed inside the titanium basket, and an electroplating solution is placed in the electroplating cell, wherein the electroplating solution immerses the anode material, the cathode material, and the titanium basket. The method comprises: Immersing the PCB board in an electroplating tank for copper plating, and depositing copper ions in the anode material onto the copper surface of the PCB board to thicken the copper surface of the PCB board; When copper particles are detected on the copper surface of the thickened PCB board, the electroplating operation is stopped; Lowering the current density in the electroplating tank, electrolyzing for a preset time after the reduction, vibrating the anode material until the anode material is saturated and does not decrease, adding a micro-etching agent into the electroplating tank to dissolve the anode mud of the anode material; Taking out the electroplating solution from the electroplating tank and filtering it, filtering the electroplating solution and putting it back into the electroplating tank; After the electroplating solution is filtered, the electroplating solution is added back into the electroplating tank to continue electroplating the PCB board; After vibrating the anode material, the method further comprises: After metal particles are precipitated on the surface of the anode material, confirming whether the metal particles are suspended in the surface layer of the electroplating solution, and determining that the metal particles are anode mud particles when the metal particles are suspended in the surface layer of the electroplating solution; Alternatively, confirming whether copper particles exist on the surface of the copper foil layer, and when the copper particles on the surface of the copper foil layer decrease or disappear, it is determined that the anode mud is loose; Alternatively, the electroplating solution is sampled to obtain the copper ion concentration in the electroplating solution, and when the copper ion concentration is lower than a first preset concentration, it is determined that the anode mud is loose.

2. The PCB copper electroplating method according to claim 1, wherein: Before immersing the PCB board in the electroplating tank for copper plating, the method further includes: 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; Removing oil stains and metal oxide layers from the surface of the PCB board, and cleaning the PCB board with pure water; Determining board surface requirements of the PCB board, and determining a protection method for the PCB board according to the board surface requirements; contacting the surface of the PCB with the chemical solution and performing high-temperature treatment; The PCB board is acid-dipped.

3. The PCB copper electroplating method according to claim 1, wherein: Before performing vibration treatment on the anode material, the method further comprises: determining a first current density in the electroplating bath; When the first current density decreases to a preset current density range, the anode mud on the surface of the anode material is subjected to low current electrolysis to separate the anode mud from the surface of the anode material.

4. The PCB copper electroplating method according to claim 3, wherein: The current density range is 0.2ASD to 0.5ASD.

5. The PCB copper electroplating method according to claim 1, wherein: After adding a micro-etching agent into the electroplating tank to dissolve the anode mud, the method further comprises: adding hydrogen peroxide to the electroplating solution and heating the electroplating solution; When the electroplating solution is heated to a first preset temperature, performing a first air stirring on the electroplating solution; After the electroplating liquid is subjected to the first air stirring for a first preset time, the electroplating liquid is filtered.

6. The PCB copper electroplating method according to claim 5, characterized in that: The filtering of the electroplating solution comprises: stopping the first air stirring and pouring the adsorption material into the electroplating solution; After the adsorption material is completely dissolved in the electroplating solution, the electroplating solution is subjected to a second air stirring, and the electroplating solution is controlled to be in a heat preservation state until the second air stirring reaches a second preset time length; turning off the second air stirring and heating the electroplating solution to precipitate the adsorption material; When the temperature of the electroplating solution is lowered to a second preset temperature, a PP filter element is placed into the electroplating solution to filter the electroplating solution.

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

8. The PCB copper electroplating method according to claim 2, wherein: The copper foil layer has a thickness of 5 μm to 0.8 μm.

9. The PCB copper electroplating method according to claim 1, wherein: The vibrating treatment of the anode material comprises: The anode material is struck with a metal rod, wherein the metal stability of the metal rod is greater than that of the anode material.

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