A method and system for online treatment of organic carbon in PCB plating solution

Abstract

This invention relates to the field of printed circuit board (PCB) purification technology, and more particularly to an online method and system for treating organic carbon in PCB plating solutions. The method includes the following steps: continuously extracting copper plating solution from the PCB electroplating copper bath and conveying it at a constant flow rate along a preset closed channel; allowing the copper plating solution to sequentially flow through an adsorption treatment zone, a separation treatment zone, and an ultrafiltration treatment zone, maintaining continuous flow and leak-free delivery throughout the process; ensuring full contact between the copper plating solution delivered to the adsorption treatment zone and the adsorption packing material, thereby depositing and adhering the total organic carbon in the copper plating solution onto the surface of the adsorption packing material through pure physical adsorption. This invention replaces the traditional offline intermittent process with an integrated treatment mechanism of online closed circulation, multi-stage physical adsorption, and gradient precision interception. It can efficiently remove organic carbon and impurities from the copper plating solution without the need for reagents or heating, thereby improving the continuity and efficiency of PCB electroplating production and enhancing the reliability of electroplating quality.

Description

Technical Field

[0001] This invention relates to the field of printed circuit purification technology, and in particular to an online method and system for treating organic carbon in PCB plating solutions. Background Technology

[0002] In the PCB copper plating process, the generation of TOC (Total Organic Carbon) in the plating bath is mainly related to the introduction, decomposition, and residue of organic matter in the plating solution. The core principles involve the consumption of organic additives, the accumulation of byproducts, and the introduction of external contaminants during the plating process. TOC in the PCB copper plating bath is an important indicator of the organic contaminant content in the plating solution. Excessive TOC concentration directly affects plating quality, process stability, and product reliability, such as decreased plating quality, copper plating defects within holes, and impaired process stability. Therefore, it is necessary to regularly monitor the TOC concentration in the plating solution and take preventative measures.

[0003] Existing offline cleaning technology involves pumping the chemical solution requiring carbon treatment into a carbon treatment tank, adding hydrogen peroxide, mixing and stirring for 4 hours, raising the temperature to 66°C and maintaining that temperature while agitating with air for 24 hours, then turning off the heating and agitation and cooling to room temperature. The agitator is then turned on to add 12g / L of carbon powder, which must be pre-wetted before being added to the tank. Stirring continues for 2 hours, after which the agitator is turned off to allow the carbon powder to settle. This settling process takes 4-6 hours until the carbon powder has completely settled to the bottom. The chemical solution is then pumped to a spare tank to confirm the carbon treatment effect. It is evident that this process is cumbersome and time-consuming, leading to PCB production stagnation and efficiency losses. Summary of the Invention

[0004] Therefore, it is necessary to provide a method and system for online treatment of organic carbon in PCB plating solution to solve at least one of the above-mentioned technical problems.

[0005] To achieve the above objectives, an online treatment method for organic carbon in PCB plating solution is provided, the method comprising the following steps: Step S1: The copper plating solution in the PCB copper plating tank is continuously extracted and transported along the preset closed flow channel at a constant flow rate; the copper plating solution flows through the adsorption treatment zone, the separation treatment zone and the ultrafiltration treatment zone in sequence, keeping the copper plating solution flowing continuously and without leakage throughout the process. Step S2: The copper plating solution delivered to the adsorption treatment zone is brought into full contact with the adsorption packing. Through pure physical adsorption, the total organic carbon in the copper plating solution is deposited and attached to the surface of the adsorption packing, thus completing the adsorption and fixation of organic pollutants in the copper plating solution. Step S3: The copper plating solution after adsorption treatment is sent to the separation treatment zone to separate and remove the suspended adsorbed and aggregated impurities in the copper plating solution. Step S4: The copper plating solution after separation is introduced into the ultrafiltration treatment zone to remove residual organic carbon and suspended solid impurities in the copper plating solution; the copper plating solution after ultrafiltration is returned to the PCB electroplating copper bath to achieve uninterrupted circulation treatment of the copper plating solution.

[0006] Preferably, the present invention also provides an online organic carbon treatment system for PCB plating solutions, used to perform the above-described online organic carbon treatment method for PCB plating solutions, the online organic carbon treatment system for PCB plating solutions comprising: The extraction module is used to continuously extract the copper plating solution from the PCB copper plating tank and transport it along a preset closed flow channel at a constant flow rate; so that the copper plating solution flows through the adsorption treatment zone, separation treatment zone and ultrafiltration treatment zone in sequence, maintaining the continuous flow of the copper plating solution throughout the process and ensuring leak-free transport. The adsorption module is used to bring the copper plating solution delivered to the adsorption treatment zone into full contact with the adsorption packing. Through pure physical adsorption, the total organic carbon in the copper plating solution is deposited and attached to the surface of the adsorption packing, thus completing the adsorption and fixation of organic pollutants in the copper plating solution. The separation module is used to send the copper plating solution after adsorption treatment into the separation treatment zone to separate and remove suspended adsorbed and aggregated impurities in the copper plating solution. The ultrafiltration module is used to introduce the separated copper plating solution into the ultrafiltration treatment zone to trap residual organic carbon and suspended solid impurities in the copper plating solution; the ultrafiltration-treated copper plating solution is then returned to the PCB electroplating copper bath to achieve uninterrupted circulation of the copper plating solution.

[0007] This invention fundamentally changes the traditional offline processing model, which relies on intermittent operation, long-term settling, and manual transfer, through a fully online physical circulation processing mechanism. It achieves uninterrupted online removal of organic carbon contaminants from copper plating solutions, significantly improving the continuity and timeliness of the PCB electroplating process. This allows the overall processing rhythm to match the production line in real time, avoiding production stoppages and efficiency losses caused by offline processing. Compared to traditional offline processes, this invention relies on the synergistic effect of closed-loop conveying, graded interception, and gradient ultrafiltration to achieve efficient and stable removal of organic contaminants. It requires no chemical reagents, no heating or stirring, and does not disrupt the original composition and process balance of the plating solution, effectively ensuring the consistency and reliability of electroplating quality. Operating in a closed-loop manner, it produces no waste liquid discharge and no secondary pollution, significantly reducing manual operation and material consumption while improving the safety and stability of the processing. The overall technical solution simplifies the process flow, shortens the processing cycle, and significantly improves the automation level of PCB copper plating solution maintenance, providing stable support for high-quality, continuous, and low-cost PCB electroplating production. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the steps involved in an online treatment method for organic carbon in PCB plating solution. Figure 2This is a schematic diagram of the online processing flow in this embodiment; Figure 3 This is a schematic diagram of the online cleaning equipment in this embodiment; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0009] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0010] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0011] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0012] To achieve the above objectives, please refer to Figures 1 to 3 A method for online treatment of organic carbon in PCB plating solution, the method comprising the following steps: Preferably, in step S1: the copper plating solution in the PCB copper plating tank is continuously extracted and transported along a preset closed flow channel at a constant flow rate; the copper plating solution flows through the adsorption treatment zone, the separation treatment zone and the ultrafiltration treatment zone in sequence, so that the copper plating solution is continuously flowing and transported without leakage throughout the process. Optionally, in step S1, continuously extracting the copper plating solution from the PCB copper plating bath specifically involves: A magnetically driven pump is sealed and connected to the outlet of the PCB copper plating tank. Set the pump operating frequency to 30Hz–50Hz and start the pump to perform the copper plating solution extraction action. Pressure sampling points are set up in a closed flow channel to collect the delivery pressure value in real time. When the delivery pressure is higher than 0.3MPa, the preset frequency of the pump body is gradually reduced; when the delivery pressure is lower than 0.1MPa, the preset frequency of the pump body is gradually increased. The copper plating solution is directionally transported along a closed channel, with the channel being guided in the order of adsorption treatment zone, separation treatment zone, and ultrafiltration treatment zone.

[0013] In this embodiment, the inlet of the magnetically driven pump and the outlet of the PCB copper plating tank are rigidly connected using a sealed joint. A sealing gasket is installed at the connection point to form a sealed connection structure, preventing external air and impurities from entering the flow channel. The magnetically driven pump is started, and the pump's operating frequency is set within the range of 30Hz–50Hz. The pump operates at this frequency, continuously drawing copper plating solution out of the PCB copper plating tank, creating a continuous output of copper plating solution. A pressure acquisition point is placed in the middle section of the sealed flow channel, and a pressure sensor is used to collect the delivery pressure value inside the flow channel in real time. The acquired signal is output as a continuous electrical signal without human intervention or adjustment.

[0014] The real-time delivery pressure value collected by the pressure sensor is compared with a preset pressure range. The lower limit of the preset pressure range is set at 0.1 MPa, and the upper limit is set at 0.3 MPa. When the collected delivery pressure value is higher than 0.3 MPa, the operating frequency of the magnetic drive pump is gradually reduced according to a fixed gradient. The reduction process continues until the pressure value falls back into the preset range. When the collected delivery pressure value is lower than 0.1 MPa, the operating frequency of the magnetic drive pump is gradually increased according to a fixed gradient. The increase process continues until the pressure value rises back into the preset range, thereby maintaining stable pressure inside the flow channel.

[0015] After pressure and frequency regulation, the extracted copper plating solution is directionally conveyed along a closed flow channel, sequentially connecting the flow channel to each processing zone according to a preset path. First, the connection between the flow channel and the adsorption treatment zone is opened, allowing the copper plating solution to stably enter the adsorption treatment zone. Once the adsorption treatment zone is full of copper plating solution, the connection between the adsorption treatment zone and the separation treatment zone is opened, allowing the copper plating solution to sequentially enter the separation treatment zone. Subsequently, the connection between the separation treatment zone and the ultrafiltration treatment zone is opened, allowing the copper plating solution to continuously enter the ultrafiltration treatment zone. Throughout the entire conveying process, the closed flow channel remains completely sealed, preventing the entry of external media. The copper plating solution exhibits no leakage, backflow, or interruption, steadily flowing through each processing zone in a fixed direction, completing the continuous conveying operation of the copper plating solution.

[0016] During the transport process, the flow channel diameter remains fixed in each section, without any artificial changes. Stable flow rate and velocity control are achieved solely through frequency regulation and pressure feedback of the magnetically driven pump. The flow channels between each processing zone remain continuously connected, without any blocking structures or bypass branches. This ensures that the copper plating solution flows sequentially through the adsorption, separation, and ultrafiltration zones in a constant state, providing stable copper plating solution supply conditions for subsequent adsorption, separation, and ultrafiltration processes. The entire process is performed using purely physical transport operations, without the addition of chemical reagents or the application of external forces such as heating or stirring, maintaining the original composition of the copper plating solution unchanged.

[0017] Optionally, the process of conveying the material at a constant flow rate along a preset closed channel in step S1 specifically involves: Establish a linkage control between the flow regulating valve at the outlet of the PCB copper plating tank and the magnetic drive pump to perform staged flow delivery; In the first stage, the copper plating solution is introduced into the starting end of the flow channel at a flow rate of 5L / min. The second stage switches to a rated flow rate of 10L / min to ensure stable transmission of the copper plating solution within the flow channel; Adjust the diameter of each section of the flow channel to 8mm–12mm to eliminate internal flow obstruction and allow the copper plating solution to pass through each processing area in a predetermined order.

[0018] In this embodiment, a flow regulating valve is installed at the outlet of the PCB copper plating tank. An electrical linkage control structure is established between the control terminal of the flow regulating valve and the magnetically driven pump, so that the opening signal of the regulating valve and the output status of the pump body respond synchronously. The copper plating solution is delivered in stages through linkage control. The flow regulating valve and the flow channel are fixedly assembled with a sealed flange. The flow channel adopts a corrosion-resistant and sealed pipeline with no bypass branches or open interfaces throughout the entire process, maintaining a closed delivery environment.

[0019] The first stage of delivery involves adjusting the flow control valve to the corresponding parameters, allowing the copper plating solution to be output at a fixed flow rate of 5 L / min. This flow rate introduces the copper plating solution into the beginning of the closed channel, filling the internal space and expelling any residual air, thus creating a continuous and stable liquid flow. After the first stage of delivery has completely filled the beginning of the channel, the linkage control remains unchanged, and the second stage flow switching process begins.

[0020] The second stage of delivery is executed by synchronously adjusting the opening of the flow regulating valve and the output parameters of the magnetic drive pump to switch the delivery flow rate to the rated flow rate of 10L / min, ensuring that the copper plating solution is continuously transported in a constant state within the flow channel. The diameter of each section of the sealed flow channel is uniformly adjusted to 8mm–12mm, and protrusions, bends, and blockages inside the flow channel are cleaned to eliminate internal flow obstructions and maintain a smooth inner wall of the flow channel, allowing the copper plating solution to flow stably in a laminar flow pattern.

[0021] The flow channels are controlled in a preset sequence, sequentially connecting the interfaces of the adsorption treatment zone, separation treatment zone, and ultrafiltration treatment zone, allowing the copper plating solution to pass through each treatment zone in a fixed order. The connecting channels between each treatment zone are set with the same diameter, direction, and slope, preventing sudden changes in flow velocity and flow disturbances. The entire process maintains a linked control mode, without heating, stirring, or chemical addition; a constant flow rate is achieved solely through mechanical adjustment and linked control, ensuring the copper plating solution completely passes through all treatment zones.

[0022] Preferably, in step S2: the copper plating solution delivered to the adsorption treatment zone is brought into full contact with the adsorption packing, and the total organic carbon in the copper plating solution is deposited and attached to the surface of the adsorption packing through pure physical adsorption, thereby completing the adsorption and fixation of organic pollutants in the copper plating solution. Optionally, in step S2, ensuring that the copper plating solution delivered to the adsorption treatment zone is in full contact with the adsorption filler includes: The copper plating solution is fed into the adsorption treatment zone via a multi-point distribution device. Adjust the liquid distribution opening of the multi-point liquid distribution device so that the liquid distribution range covers the entire effective cross section of the upper layer of packing. This drives the copper plating solution to penetrate the filler layer evenly from top to bottom; Construct a reciprocating flow path and determine the interaction path between the copper plating solution and the filler to ensure full-area contact between the copper plating solution and the surface of each part of the filler. Total organic carbon is attached to the filler surface through physical contact, and the distribution area and opening of the multi-point distribution device are adjusted according to the real-time flow rate of the copper plating solution.

[0023] In this embodiment, the copper plating solution delivered to the adsorption treatment zone is fed into the treatment chamber via a multi-point distribution device located at the top. The multi-point distribution device is connected to the front-end sealed flow channel by a sealed sleeve. The copper plating solution enters the distribution device at a flow rate of 10 L / min. The distribution device is evenly distributed laterally along the upper layer of the adsorption packing, and the inlet holes are arranged at equal intervals, so that the copper plating solution enters the area above the packing in a diversion manner.

[0024] Adjust the opening of the multi-point liquid distribution device to 3–5 mm to ensure that the copper plating solution completely covers the entire effective cross-section of the upper layer of the adsorption packing, without any localized liquid shortage or overflow. Under a fixed liquid level difference, the copper plating solution is driven to vertically penetrate through the adsorption packing layer from top to bottom. The packing layer height is controlled at 200–300 mm, and the penetration direction remains vertically downward. A reversible flow-blocking structure is installed inside the adsorption packing to form a reciprocating flow path, extending the flow path of the copper plating solution within the packing layer to 1.5–2 times that of a direct flow path, ensuring full-area contact between the copper plating solution and all surfaces of the packing.

[0025] The total organic carbon in the copper plating solution is directly deposited onto the surface of the adsorption filler through physical contact, without any stirring, heating, or chemical agents applied throughout the process. The copper plating solution flow rate is collected in real time during adsorption. When the flow rate varies within the range of 5–10 L / min, the distribution area and opening of the multi-point distribution device are adjusted synchronously. Increasing the flow rate increases the distribution opening, while decreasing the flow rate decreases the distribution opening, ensuring that the distribution state matches the real-time flow rate.

[0026] After adsorption and contact are completed, the copper plating solution is discharged from the bottom outlet of the adsorption treatment zone. The discharge flow rate is consistent with the feed flow rate, ensuring continuous flow within the adsorption treatment zone. The entire process employs a purely physical online carbon treatment method, without altering the original ionic composition of the copper plating solution. Sufficient contact between the copper plating solution and the adsorption packing is achieved solely through solution distribution control, path construction, and flow rate matching.

[0027] Optionally, step S2, which involves depositing the total organic carbon in the copper plating solution onto the surface of the adsorption filler through purely physical adsorption, includes: The adsorption treatment zone is maintained at a preset ambient temperature and pressure environment to control the continuous flow of copper plating solution within the filler layer. No stirring, heating or chemical reagents are applied during the adsorption process, allowing the total organic carbon in the copper plating solution to gradually deposit on the surface of the filler. The copper plating solution inlet position is switched according to a preset fixed time cycle, so that organic pollutants are evenly distributed and adhered to the entire filler area. The copper plating solution that has completed adsorption is continuously discharged to the separation and processing area.

[0028] In this embodiment, the adsorption treatment zone adopts a closed cavity structure. The internal temperature is stably controlled at 23℃±2℃ by an external temperature control module, and the internal pressure is maintained at 0.1MPa standard atmospheric pressure. The cavity is not equipped with pressurization, depressurization, heating, or cooling adjustment devices, maintaining a preset normal temperature and pressure environment. The copper plating solution, delivered by the multi-point liquid distribution device, enters the packing layer at a rated flow rate of 10L / min, continuously flowing along a reciprocating zigzag path. The packing layer thickness is set to 250mm, and the residence time of the copper plating solution in the packing layer is controlled at 12s-15s, maintaining continuous and uninterrupted flow.

[0029] During the adsorption process, the stirring device inside the adsorption treatment zone remains off, and the heating module remains powered off. No chemical reagents such as hydrogen peroxide, carbon powder, or acid-base adjusters are added to the copper plating solution, and the original ionic composition and liquid phase state of the copper plating solution are not altered. The copper plating solution flows slowly through the filler layer, and the total organic carbon in it gradually deposits and adheres to the surface of the adsorption filler under physical contact. The entire process involves only physical adhesion, without any chemical reactions such as oxidation or decomposition, and completely follows the purely physical mechanism of online carbon treatment.

[0030] The liquid inlet orientation switching cycle is set to 300 seconds. The orientation switching action is executed by the zone control valve group of the multi-point liquid distribution device, sequentially opening the left liquid distribution zone, the middle liquid distribution zone, and the right liquid distribution zone, and cyclically switching the conduction state. Each switching action takes 2 seconds, and the opening degree of the control valve group is adjusted synchronously to ensure that the copper plating solution is evenly applied to different transverse areas of the filler layer, so that the total organic carbon is evenly attached to all filler areas, maintaining a consistent adsorption load throughout the filler.

[0031] The bottom outlet valve of the adsorption treatment zone maintains a fixed opening, stably discharging the adsorbed copper plating solution at a flow rate of 10 L / min, with the discharge flow rate equal to the feed flow rate. The discharged copper plating solution is directly transported to the separation treatment zone through a closed flow channel with a diameter of 8 mm-12 mm. The flow channel is completely free of diversion, openings, and stagnation, achieving continuous connection between the adsorption treatment and separation treatment processes and forming a stable online processing flow channel.

[0032] Optionally, the adsorption and fixation of organic pollutants in step S2 specifically involves: The copper plating solution is fed into the adsorption treatment zone in a continuous feeding mode, so that the copper plating solution completely fills the flow gap inside the filler layer. The organic pollutants are separated from the copper plating solution through physical adhesion, and the inlet and outlet diameters and flow rates of the adsorption treatment zone are kept consistent. The feed rate is matched with the discharge rate to perform the export action, opening the outlet channel and introducing the processed copper plating solution into the separation treatment area.

[0033] In this embodiment, a continuous feeding mode is used to introduce the copper plating solution into the adsorption treatment zone. The feed flow rate is set to 10L / min. The copper plating solution is evenly distributed to the upper layer of the adsorption packing through a multi-point liquid distribution device. Under the combined action of gravity and flow pressure, it gradually fills all the flow gaps inside the packing layer. The packing layer has a filling height of 250mm and the internal porosity remains stable. The copper plating solution completely wets the entire packing area in a laminar flow state, with no local cavities, no local liquid accumulation, and no flow interruption areas formed.

[0034] The separation of organic pollutants relies on physical adhesion. During contact with the adsorption packing surface, the total organic carbon in the copper plating solution is deposited onto the packing layer, achieving phase separation between the organic pollutants and the bulk copper plating solution. No stirring or heating is applied throughout the process, no chemical reagents are added, and the original ionic composition of the copper plating solution remains unchanged; the separation is accomplished solely through the purely physical action of online carbon treatment. The inlet and outlet diameters of the adsorption treatment zone are both set within the range of 8mm–12mm, and the inlet and outlet flow rates are controlled at 10L / min to maintain a stable flow cross-section and delivery flow rate.

[0035] The outlet valve of the adsorption treatment zone maintains a fixed opening, and the copper plating solution is discharged at a discharge rate of 10 L / min, which perfectly matches the feed rate. The outlet channel is continuously open without any opening or closing operation. The treated copper plating solution flows out stably from the bottom outlet of the adsorption treatment zone without backflow, turbulence, or flow fluctuation. The discharge process runs synchronously with the feeding process, forming a continuous and stable material flow state.

[0036] The exported copper plating solution is directly transported to the inlet of the separation treatment area along a closed flow channel. The flow channel remains sealed throughout, with no openings, branches, or external media intervention. The adsorption and separation treatments form a continuous process flow. The entire adsorption and fixation process is carried out under normal temperature and pressure conditions, with the temperature controlled at 23℃±2℃ and the pressure at 0.1MPa standard atmosphere. There is no manual intervention or parameter changes throughout the process, and the adsorption and fixation of organic pollutants and the transportation of copper plating solution are completed under a fixed operating state.

[0037] Preferably, step S3: the copper plating solution after adsorption treatment is sent to the separation treatment zone to separate and remove the suspended adsorbed and aggregated impurities in the copper plating solution. Optionally, the separation and removal of suspended adsorbed and aggregated impurities in step S3 specifically involves: The copper plating solution after adsorption treatment is introduced into the separation treatment zone; Two levels of fixed interception surfaces with apertures of 80μm and 25μm are set along the flow path of the copper plating solution. The first-stage interception targets adsorbed and aggregated impurities with pore sizes greater than 80 μm. The second-stage interception targets suspended impurities with pore sizes between 25μm and 80μm. The intercepted impurities are retained in the retention cavity between the two-stage interception surfaces; Adjust the flow rate of the copper plating solution according to the amount of impurities accumulated in the retention cavity so that the copper plating solution can continuously pass through the internal channel of the separation treatment zone.

[0038] In this embodiment, the copper plating solution that has undergone adsorption treatment is transported to the inlet port of the separation treatment zone at a constant flow rate of 10L / min through a closed flow channel with a diameter of 8mm–12mm. The separation treatment zone adopts a horizontal straight-through cavity structure and maintains an operating environment of ambient temperature 23℃±2℃ and ambient pressure 0.1MPa. No heating, stirring or chemical reagent addition is applied throughout the process. Only physical classification and interception technology is used to perform impurity separation.

[0039] Two stages of fixed interception structures are installed sequentially along the flow direction of the copper plating solution. Both stages are supported by rigid frames and are arranged perpendicular to the flow direction. The pore size of the first stage interception surface is set to 80μm, and the pore size of the second stage interception surface is set to 25μm. The distance between the two stages is maintained at 50mm–80mm, forming a graded interception channel. The copper plating solution first flows through the 80μm first-stage interception surface, where adsorbed and agglomerated impurities with a particle size larger than 80μm are directly blocked on the inlet side of the interception surface and cannot pass through the interception pores. Subsequently, the copper plating solution enters the 25μm second-stage interception surface, where suspended impurities with a particle size range of 25μm–80μm are blocked outside this stage interception surface and do not enter the subsequent flow channels.

[0040] A closed retention chamber is set between the two-stage interception surfaces. Impurities intercepted by the first and second-stage interception surfaces are retained inside the retention chamber and do not flow forward with the copper plating solution, thus preventing impurity shedding and secondary entrainment. An impurity accumulation detection point is set at the middle of the retention chamber to collect data on the impurity accumulation height and filling volume in real time.

[0041] Based on the detected impurity accumulation data, the flow rate of the copper plating solution is adjusted in a closed loop. When the accumulation reaches a set threshold, the flow rate is reduced from 10 L / min to 8-9 L / min; when the accumulation decreases to a safe range, the flow rate is restored to 10 L / min. After the speed adjustment, the copper plating solution continuously and smoothly passes through the two-stage interception surface and the direct channel inside the separation treatment zone, maintaining a continuous, uninterrupted, unblocked, and backflow-free operating state, thus completing the graded physical separation of suspended adsorbed and agglomerated impurities.

[0042] Optionally, step S3, in which suspended adsorbed and aggregated impurities are separated and removed, further includes: The copper plating solution is controlled to flow in a laminar flow pattern along a straight channel within the separation treatment zone; A fixed interception mesh with an aperture of 25μm is installed in the straight channel; The suspended adsorbed and aggregated impurities are trapped on the side of the interception mesh facing the liquid inlet, allowing the main liquid phase of the copper plating solution to pass through the mesh openings and be output outwards. The copper plating solution is discharged at a rate equal to the feed rate, and the separated copper plating solution is introduced into the ultrafiltration treatment zone.

[0043] In this embodiment, a straight through-flow channel structure is adopted inside the separation processing zone. The copper plating solution after two stages of interception is introduced into the straight channel. By controlling the channel diameter to be 8mm-12mm and the delivery flow rate to be stable at 10L / min, the copper plating solution forms a stable laminar flow pattern in the straight channel. The liquid flow direction remains parallel to the channel axis, and no eddies, turbulence, or backflow are generated, providing stable flow conditions for subsequent interception operations.

[0044] A fixed intercepting mesh is installed in the middle of the straight channel. The mesh is fixedly installed using an integral rigid frame, and is set perpendicular to the liquid flow direction. The mesh aperture is uniformly set at 25μm, and the mesh is flat, without deformation, damage, or pore blockage. The copper plating solution contacts the intercepting mesh in a stable laminar flow state. Residual suspended adsorbed and aggregated impurities in the liquid flow are blocked on the side of the intercepting mesh facing the liquid inlet. Impurities continue to accumulate on the liquid inlet side of the mesh, without passing through the mesh aperture, without falling off, or being secondary entrained.

[0045] The liquid phase of the copper plating solution is uniformly transported through all the pores of the 25μm interception mesh under constant flow pressure, and continues to be transported forward along a straight channel. The liquid phase composition does not change, no chemical reagents are added, and no external intervention operations such as heating or stirring are performed. The entire process follows the pure physical separation mechanism of the online carbon treatment process, and the separation of impurities from the copper plating solution is achieved solely through mechanical interception.

[0046] The outlet valve of the separation treatment zone maintains a fixed opening, and the copper plating solution is discharged at a rate of 10 L / min. The discharge rate is kept equal to the feed rate to ensure stable flow and no pressure fluctuations within the separation treatment zone. The separated copper plating solution is directly transported to the inlet port of the ultrafiltration treatment zone through a closed flow channel. The flow channel is completely sealed with no openings, branches, or external media, forming a continuous online processing flow between the impurity separation process and the ultrafiltration retention process.

[0047] Preferably, in step S4: the copper plating solution after separation is introduced into the ultrafiltration treatment zone to trap residual organic carbon and suspended solid impurities in the copper plating solution; the copper plating solution after ultrafiltration is returned to the PCB electroplating copper bath to achieve uninterrupted circulation treatment of the copper plating solution.

[0048] Optionally, the specific steps for retaining residual organic carbon and suspended solid impurities in the copper plating solution in step S4 are as follows: The separated copper plating solution is then introduced into the ultrafiltration treatment zone. A three-level gradient interception surface with interception accuracies of 10 μm, 1 μm and 0.1 μm is set along the flow direction; The first-stage interception surface intercepts suspended solid impurities larger than 10 μm; The second-stage interception surface intercepts suspended impurities and organic carbon aggregates of 1μm–10μm; The third-stage interception surface intercepts residual organic carbon and fine impurities smaller than 1 μm; The copper plating solution is controlled to pass through three stages of interception surfaces at a uniform speed, thereby confining various impurities to the inlet side of the corresponding interception surfaces.

[0049] In this embodiment, the copper plating solution after separation is introduced into the ultrafiltration treatment zone through a closed flow channel with a diameter of 8mm–12mm. The flow rate is maintained at 10L / min. The ultrafiltration treatment zone adopts a sealed series chamber structure. The internal ambient temperature is controlled at 23℃±2℃ and the pressure is maintained at 0.1MPa standard atmospheric pressure. No heating, stirring and reagent addition devices are installed inside the chamber. The entire process is a purely physical interception operation.

[0050] Three rigidly fixed gradient interception surfaces are installed sequentially along the flow direction of the copper plating solution. These surfaces are assembled using a frame-type clamping system, perpendicular and orthogonal to the flow direction. The interception precision of the three levels of interception surfaces is set sequentially to 10μm, 1μm, and 0.1μm along the flow direction, with a uniform spacing of 70mm between adjacent interception surfaces, forming a progressively more precise interception channel. When the copper plating solution enters the channel in a uniform laminar flow state, it first contacts the 10μm first-level interception surface. Suspended solid impurities with a particle size larger than 10μm are completely blocked on the inlet side of the interception surface, unable to pass through the interception pores to enter the next treatment area.

[0051] The copper plating solution continues to flow forward after passing through the first-stage interception surface, reaching the 1μm second-stage interception surface. Suspended impurities and organic carbon aggregates with particle sizes ranging from 1μm to 10μm are blocked by the interception surface and remain on the side of the interception surface facing the inlet. Subsequently, the copper plating solution enters the 0.1μm third-stage interception surface, where residual organic carbon molecules and fine impurities with particle sizes smaller than 1μm are intercepted, achieving full-scale blocking of residual contaminants in the copper plating solution.

[0052] By maintaining a constant feed flow rate, fixed channel diameter, and uniform interception surface installation angle, the copper plating solution is controlled to pass through three levels of interception surfaces at a uniform speed. The receiving area of ​​each interception surface remains uniform, without flow deviation, short circuits, or local stagnation. Impurities intercepted by each interception surface are confined to the inlet side area of ​​the corresponding interception surface, preventing detachment, back-mixing, and secondary entrainment. The entire interception process is executed according to the requirements of the online carbon treatment process, without changing the original composition of copper ions, sulfate ions, and chloride ions in the copper plating solution. Stable interception and limitation of residual organic carbon and suspended solid impurities are achieved solely through three-stage gradient precision interception.

[0053] Of particular importance, step S4, which involves retaining residual organic carbon and suspended solid impurities in the copper plating solution, also includes: The copper plating solution after separation is passed into the ultrafiltration treatment zone in a full-flow state, so that the copper plating solution evenly covers the entire effective area of ​​the interception surface. The copper plating solution is allowed to pass through the interception surface in its entirety, thus achieving all-round, dead-angle-free blocking of residual organic carbon in the copper plating solution that has not been adsorbed. Simultaneously implement full-coverage blocking of suspended solid impurities inside the copper plating solution along the same path; The flow direction of the copper plating solution in the retention area is switched according to a preset time cycle so that the retention surface is evenly loaded with impurities; The copper plating solution that has completed the interception operation is smoothly discharged along the preset channel and directed to the return pipeline interface.

[0054] In this embodiment, the separated copper plating solution is transported to the inlet of the ultrafiltration treatment zone's interception area through a closed flow channel with a diameter of 8mm–12mm. The feed flow rate is controlled to be stable at 10L / min. By adjusting the inlet valve opening and the flow channel resistance, the copper plating solution completely fills the internal cavity of the interception area in a full-flow state. There is no residual air, no local liquid shortage, and no wall-adhering flow phenomenon inside the cavity. The copper plating solution uniformly covers the entire effective working area of ​​the three-level gradient interception surface of 10μm, 1μm, and 0.1μm, ensuring that every position on the interception surface is flushed by the copper plating solution with the same pressure and flow rate.

[0055] Under full-flow conditions, the copper plating solution flows vertically through each stage of the intercepting surfaces in a continuous, integrated manner. The liquid flow maintains a stable laminar flow pattern, without generating eddies, turbulence, or flow deviation. The intercepting surfaces, through physical barrier effects, provide comprehensive, all-around protection against unadsorbed residual organic carbon in the copper plating solution, confining it to the inlet side of the intercepting surface and preventing it from passing through. Simultaneously, it provides full-coverage protection against suspended solid impurities within the copper plating solution along the same path, ensuring that organic pollutants and solid impurities are intercepted synchronously within the same flow path, preventing missed interception, side-winding, or secondary entrainment. The entire process maintains a purely physical interception mechanism.

[0056] Following a preset time period of 300 seconds, the flow direction of the copper plating solution is switched via four-way reversing valves configured at both ends of the ultrafiltration treatment zone. The reversing valves complete the opening adjustment and flow direction switch within 2 seconds, maintaining a stable flow rate before and after the switch. After the copper plating solution flow direction changes, it enters the chamber from the opposite side of the interception area, allowing the inlet and outlet sides of the interception surface to alternately bear impurities. This prevents continuous accumulation of impurities on one side of the interception surface, avoiding localized blockages and ensuring a uniform impurity load across the entire interception surface.

[0057] The copper plating solution, after the retention process, is smoothly discharged through a pre-designed straight-through channel within the ultrafiltration treatment zone. The discharge flow rate is strictly controlled at 10 L / min, perfectly matching the feed flow rate. The discharged copper plating solution is then directed to a dedicated interface on the return pipeline. This interface is rigidly connected to the return pipeline using a sealed flange, ensuring no open sections, branches, or external media infiltration throughout the entire process, without altering the original composition or state of the copper plating solution. The entire operation is conducted at ambient temperature and pressure (23℃±2℃, 0.1 MPa), without adding any chemical reagents, activating any stirring devices, or implementing any heating treatment. The deep retention of residual organic carbon and suspended solid impurities is achieved solely through physical methods such as full-flow control, vertical flow, timed reversal, and directional discharge.

[0058] Of particular importance is that, in step S4, the copper plating solution after ultrafiltration is returned to the PCB copper plating bath as follows: A closed reflux channel is formed by sealing the reflux pump with the liquid outlet port of the ultrafiltration treatment zone. Adjust the output parameters of the reflux pump to keep the copper plating solution reflux rate consistent with the initial extraction rate; The purified copper plating solution is introduced tangentially along the inner wall of the PCB copper plating tank, forming a downstream conveying trajectory along the tank wall; This allows the refluxed copper plating solution to gradually blend with the original copper plating solution in the tank. Synchronize and coordinate the actions of copper plating solution extraction, flow channel transportation, zoned treatment, and pipeline return; Construct a fully enclosed, continuously operating, and uninterrupted online circulation treatment path for copper plating solution.

[0059] In this embodiment, the inlet port of the reflux pump and the outlet port of the ultrafiltration treatment zone are rigidly connected using a sealing flange and a corrosion-resistant sealing gasket. There are no gaps or leaks between the reflux pump and the pipeline, forming a closed reflux channel from the outlet of the ultrafiltration treatment zone to the PCB copper plating bath. The entire reflux channel uses a sealed, corrosion-resistant pipeline with a diameter of 8mm–12mm, without any openings, branches, or external interfaces, ensuring that the copper plating solution does not come into contact with external air or impurities during the reflux process, maintaining a closed-loop online circulation.

[0060] The operating frequency and output flow rate of the reflux pump are precisely adjusted, with the operating frequency set to 30Hz–50Hz to ensure a stable copper plating solution reflux rate of 10L / min, perfectly matching the initial magnetic drive pump's extraction rate. A flow feedback mechanism monitors the reflux flow rate in real time, automatically fine-tuning the pump's output power when deviations occur. This ensures the reflux flow rate remains balanced with the extraction flow rate, maintaining stable internal system pressure and preventing pressure spikes, negative pressures, or flow fluctuations.

[0061] The purified copper plating solution is transported through a return pipeline to the tangential inlet port at the top of the PCB copper plating tank. It is then injected horizontally tangentially along the inner wall of the tank, creating a continuous downstream flow path without any disturbances such as direct impact, splashing, or eddies. The returned solution flows slowly downwards along the tank wall, gradually contacting and merging with the existing copper plating solution without altering the main flow pattern or disrupting the original liquid level balance.

[0062] The system synchronously coordinates the actions of each execution unit in copper plating solution extraction, closed-channel conveying, adsorption treatment, separation treatment, ultrafiltration retention, and pipeline return. The flow rate of each stage is uniformly 10L / min, and the pipe diameter is uniformly 8mm–12mm. The operation status is maintained in real time. Through the synchronous operation of each unit, a fully closed, continuous, and uninterrupted online circulation treatment path for copper plating solution is constructed, from the PCB copper plating tank outlet, through multi-stage treatment, and back to the tank. The entire process follows a purely physical treatment mechanism, without the addition of chemical agents or heating and stirring, achieving uninterrupted circulation and purification of the copper plating solution.

[0063] Preferably, the present invention also provides an online organic carbon treatment system for PCB plating solutions, used to perform the above-described online organic carbon treatment method for PCB plating solutions, the online organic carbon treatment system for PCB plating solutions comprising: The extraction module is used to continuously extract the copper plating solution from the PCB copper plating tank and transport it along a preset closed flow channel at a constant flow rate; so that the copper plating solution flows through the adsorption treatment zone, separation treatment zone and ultrafiltration treatment zone in sequence, maintaining the continuous flow of the copper plating solution throughout the process and ensuring leak-free transport. The adsorption module is used to bring the copper plating solution delivered to the adsorption treatment zone into full contact with the adsorption packing. Through pure physical adsorption, the total organic carbon in the copper plating solution is deposited and attached to the surface of the adsorption packing, thus completing the adsorption and fixation of organic pollutants in the copper plating solution. The separation module is used to send the copper plating solution after adsorption treatment into the separation treatment zone to separate and remove suspended adsorbed and aggregated impurities in the copper plating solution. The ultrafiltration module is used to introduce the separated copper plating solution into the ultrafiltration treatment zone to trap residual organic carbon and suspended solid impurities in the copper plating solution; the ultrafiltration-treated copper plating solution is then returned to the PCB electroplating copper bath to achieve uninterrupted circulation of the copper plating solution.

[0064] Please see Figure 2 and Figure 3 The online carbon treatment process for electroplating solutions used in this invention involves processing the copper plating solution through three modules: an adsorption machine, a separator, and an ultrafiltration machine. This process removes TOC from the plating solution through pure physical adsorption and deposition onto the packing material and precision filter element, significantly reducing its TOC value. The entire treatment process achieves zero wastewater discharge. Its working principle is as follows: (1) Pure physical adsorption: TOC + C (filler) = TOC ･ C (2) Cu has no special chemical reaction 2 + + SO4 2- =CuSO4; Cu 2 + + 2Cl - =CuCl2; 2H + + SO4 2-= H2SO4 H + + Cl - = HCl.

[0065] Preferably, the following is a comparison between the online processing of the present invention and the traditional offline processing: Offline table processing

[0066] Online form processing

[0067] From the above online and offline processing tables, it can be concluded that traditional offline carbon processing takes 4 days (96 hours), while the new online processing takes only 0.5 days (12 hours), which is only 1 / 8 of the traditional offline method.

[0068] Therefore, the embodiments should be considered as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the application are intended to be included within the invention.

[0069] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method for online treatment of organic carbon in PCB plating solution, characterized in that, Includes the following steps: Step S1: The copper plating solution in the PCB copper plating tank is continuously extracted and transported along the preset closed flow channel at a constant flow rate; the copper plating solution flows through the adsorption treatment zone, the separation treatment zone and the ultrafiltration treatment zone in sequence, keeping the copper plating solution flowing continuously and without leakage throughout the process. Step S2: The copper plating solution delivered to the adsorption treatment zone is brought into full contact with the adsorption packing. Through pure physical adsorption, the total organic carbon in the copper plating solution is deposited and attached to the surface of the adsorption packing, thus completing the adsorption and fixation of organic pollutants in the copper plating solution. Step S3: The copper plating solution after adsorption treatment is sent to the separation treatment zone to separate and remove the suspended adsorbed and aggregated impurities in the copper plating solution. Step S4: The separated copper plating solution is introduced into the ultrafiltration treatment zone to remove residual organic carbon and suspended solid impurities in the copper plating solution; The copper plating solution after ultrafiltration is returned to the PCB copper plating tank to achieve uninterrupted circulation of the copper plating solution.

2. The method for online treatment of organic carbon in PCB plating solution according to claim 1, characterized in that, Step S1, specifically the continuous extraction of copper plating solution from the PCB copper plating bath, involves: A magnetically driven pump is sealed and connected to the outlet of the PCB copper plating tank. Set the pump operating frequency to 30Hz–50Hz and start the pump to perform the copper plating solution extraction action. Pressure sampling points are set up in a closed flow channel to collect the delivery pressure value in real time. When the delivery pressure is higher than 0.3MPa, the preset frequency of the pump body is gradually reduced; when the delivery pressure is lower than 0.1MPa, the preset frequency of the pump body is gradually increased. The copper plating solution is directionally transported along a closed channel, with the channel being guided in the order of adsorption treatment zone, separation treatment zone, and ultrafiltration treatment zone.

3. The method for online treatment of organic carbon in PCB plating solution according to claim 2, characterized in that, In step S1, the conveying at a constant flow rate along a preset closed channel specifically involves: Establish a linkage control between the flow regulating valve at the outlet of the PCB copper plating tank and the magnetic drive pump to perform staged flow delivery; In the first stage, the copper plating solution is introduced into the starting end of the flow channel at a flow rate of 5L / min. The second stage switches to a rated flow rate of 10L / min to ensure stable transmission of the copper plating solution within the flow channel; Adjust the diameter of each section of the flow channel to 8mm–12mm to eliminate internal flow obstruction and allow the copper plating solution to pass through each processing area in a predetermined order.

4. The method for online treatment of organic carbon in PCB plating solution according to claim 1, characterized in that, Step S2, ensuring that the copper plating solution delivered to the adsorption treatment zone is in full contact with the adsorption packing, includes: The copper plating solution is fed into the adsorption treatment zone via a multi-point distribution device. Adjust the liquid distribution opening of the multi-point liquid distribution device so that the liquid distribution range covers the entire effective cross section of the upper layer of packing. This drives the copper plating solution to penetrate the filler layer evenly from top to bottom; Construct a reciprocating flow path and determine the interaction path between the copper plating solution and the filler to ensure full-area contact between the copper plating solution and the surface of each part of the filler. Total organic carbon is attached to the filler surface through physical contact, and the distribution area and opening of the multi-point distribution device are adjusted according to the real-time flow rate of the copper plating solution.

5. The method for online treatment of organic carbon in PCB plating solution according to claim 4, characterized in that, Step S2 involves depositing the total organic carbon in the copper plating solution onto the surface of the adsorption filler through purely physical adsorption, including: The adsorption treatment zone is maintained at a preset ambient temperature and pressure environment to control the continuous flow of copper plating solution within the filler layer. No stirring, heating or chemical reagents are applied during the adsorption process, allowing the total organic carbon in the copper plating solution to gradually deposit on the surface of the filler. The copper plating solution inlet position is switched according to a preset fixed time cycle, so that organic pollutants are evenly distributed and adhered to the entire filler area. The copper plating solution that has completed adsorption is continuously discharged to the separation and processing area.

6. The method for online treatment of organic carbon in PCB plating solution according to claim 5, characterized in that, The adsorption and fixation of organic pollutants in step S2 are specifically as follows: The copper plating solution is fed into the adsorption treatment zone in a continuous feeding mode, so that the copper plating solution completely fills the flow gap inside the filler layer. The organic pollutants are separated from the copper plating solution through physical adhesion, and the inlet and outlet diameters and flow rates of the adsorption treatment zone are kept consistent. The feed rate is matched with the discharge rate to perform the export action, opening the outlet channel and introducing the processed copper plating solution into the separation treatment area.

7. The method for online treatment of organic carbon in PCB plating solution according to claim 1, characterized in that, The specific steps for separating and removing suspended adsorbed and aggregated impurities in step S3 are as follows: The copper plating solution after adsorption treatment is introduced into the separation treatment zone; Two levels of fixed interception surfaces with apertures of 80μm and 25μm are set along the flow path of the copper plating solution. The first-stage interception targets adsorbed and aggregated impurities with pore sizes greater than 80 μm. The second-stage interception targets suspended impurities with pore sizes between 25μm and 80μm. The intercepted impurities are retained in the retention cavity between the two-stage interception surfaces; Adjust the flow rate of the copper plating solution according to the amount of impurities accumulated in the retention cavity so that the copper plating solution can continuously pass through the internal channel of the separation treatment zone.

8. The method for online treatment of organic carbon in PCB plating solution according to claim 7, characterized in that, Step S3, which involves separating and removing suspended adsorbed and aggregated impurities, also includes: The copper plating solution is controlled to flow in a laminar flow pattern along a straight channel within the separation treatment zone; A fixed interception mesh with an aperture of 25μm is installed in the straight channel; The suspended adsorbed and aggregated impurities are trapped on the side of the interception mesh facing the liquid inlet, allowing the main liquid phase of the copper plating solution to pass through the mesh openings and be output outwards. The copper plating solution is discharged at a rate equal to the feed rate, and the separated copper plating solution is introduced into the ultrafiltration treatment zone.

9. The method for online treatment of organic carbon in PCB plating solution according to claim 1, characterized in that, The specific steps for removing residual organic carbon and suspended solid impurities from the copper plating solution in step S4 are as follows: The separated copper plating solution is then introduced into the ultrafiltration treatment zone. A three-level gradient interception surface with interception accuracies of 10 μm, 1 μm and 0.1 μm is set along the flow direction; The first-stage interception surface intercepts suspended solid impurities larger than 10 μm; The second-stage interception surface intercepts suspended impurities and organic carbon aggregates of 1μm–10μm; The third-stage interception surface intercepts residual organic carbon and fine impurities smaller than 1 μm; The copper plating solution is controlled to pass through three stages of interception surfaces at a uniform speed, thereby confining various impurities to the inlet side of the corresponding interception surfaces.

10. An online organic carbon treatment system for PCB plating solution, characterized in that, For performing the online organic carbon treatment method for PCB plating solution as described in claim 1, the online organic carbon treatment system for PCB plating solution comprises: The extraction module is used to continuously extract the copper plating solution from the PCB copper plating tank and transport it along a preset closed flow channel at a constant flow rate; so that the copper plating solution flows through the adsorption treatment zone, separation treatment zone and ultrafiltration treatment zone in sequence, maintaining the continuous flow of the copper plating solution throughout the process and ensuring leak-free transport. The adsorption module is used to bring the copper plating solution delivered to the adsorption treatment zone into full contact with the adsorption packing. Through pure physical adsorption, the total organic carbon in the copper plating solution is deposited and attached to the surface of the adsorption packing, thus completing the adsorption and fixation of organic pollutants in the copper plating solution. The separation module is used to send the copper plating solution after adsorption treatment into the separation treatment zone to separate and remove suspended adsorbed and aggregated impurities in the copper plating solution. The ultrafiltration module is used to introduce the separated copper plating solution into the ultrafiltration treatment zone to trap residual organic carbon and suspended solid impurities in the copper plating solution; the ultrafiltration-treated copper plating solution is then returned to the PCB electroplating copper bath to achieve uninterrupted circulation of the copper plating solution.

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