Optimization method for reducing material consumption and wastewater discharge in copper deposition process of printed circuit board

Abstract

The invention discloses an optimization method for reducing material consumption and wastewater discharge in a printed circuit board copper deposition process. The invention relates to a copper deposition process for printed circuit board production, and aims to reduce wastewater discharge and save resources by improving a liquid management process. The method comprises the following key steps: firstly, after a skeet hanging basket on a PTH production line is treated by a degumming tank, the skeet hanging basket is hung into a washing tank to remove residual high-concentration degumming liquid medicine; thirdly, a circulating system composed of a UPVC material pipeline and a magnetic pump is installed between the post-glue-removal washing tank and the glue removal tank, and washing water containing glue removal liquid medicine is pumped back to the glue removal tank to supplement the liquid level; meanwhile, the control system is used for automatically adjusting the supply amount of tap water, maintaining the liquid level in the rinsing bath and diluting the degumming liquid medicine to ensure the stability of water quality. According to the method, consumption of chemical substances such as sodium hydroxide and potassium permanganate is reduced, wastewater discharge is remarkably reduced, and the win-win situation of environmental protection and economic benefits is achieved.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board manufacturing, and in particular to an optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards. Background Technology

[0002] In existing printed circuit board (PCB) copper plating processes, especially in the adhesive removal section of PTH production lines, the target basket, after passing through the adhesive removal tank, is directly suspended into a pre-cleaning water washing tank to remove residual high-concentration adhesive removal chemicals, which typically contain sodium hydroxide and potassium permanganate. However, this process faces significant problems: the high-concentration adhesive removal chemicals remaining in the washing tank necessitate frequent replacements, increasing chemical consumption and generating large amounts of chemically-containing wastewater, burdening the environment. Furthermore, the high operating temperature of the adhesive removal tank (up to 80°C) causes accelerated evaporation of the chemicals, leading to a continuous drop in the liquid level. This necessitates periodic replenishment with tap water, which dilutes the effective concentration of the chemicals and further increases tap water consumption. Weekly replacement and cleaning of the high-concentration adhesive removal chemicals in the washing tank wastes valuable chemicals, increases production costs, and the frequent wastewater replacement and treatment also increases the cost and complexity of wastewater treatment. In addition, traditional liquid management lacks an intelligent control system, which cannot automatically adjust the concentration or level of the medicine according to actual needs, resulting in low operating efficiency and difficulty in achieving precise control. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention provides an optimized method for reducing material consumption and wastewater discharge in the copper plating process for printed circuit boards, comprising the following steps: S1: The target basket on the PTH production line is degummed by the degumming tank and then suspended into the subsequent water washing tank to remove the residual high-concentration degumming solution, which contains sodium hydroxide and potassium permanganate. S2: Install a piping system between the degummed water washing tank and the degumming tank, consisting of a 32 mm diameter UPVC pipe, direct connectors, elbows, ball valves, and internal pressure direct connectors, and connect a 500W power, 220V voltage magnetic pump. One end of the magnetic pump is connected to a suitable position at the bottom or side of the water washing tank, and the other end is connected to a suitable position at the top or side of the degumming tank. S3: Start the magnetic pump and pump the washing water containing the adhesive remover from the washing tank to the adhesive remover tank through the pipeline system. This replenishes the liquid level lost due to evaporation or overflow caused by the working temperature of up to 80°C, and at the same time maintains a stable working liquid volume in the adhesive remover tank. S4: During the process of adding tap water to the water washing tank, the tap water supply is automatically or manually adjusted by the control system to compensate for the amount of water transferred to the adhesive removal tank, maintain the liquid level in the water washing tank, and dilute the residual adhesive removal solution to ensure the cleanliness of the workpiece surface and the stability of the water quality in subsequent processing. S5: Periodically analyze the water in the washing tank to determine whether the concentrations of sodium hydroxide and potassium permanganate meet the predetermined values, and adjust the supply of tap water through the control system based on the analysis results to ensure the effectiveness of the adhesive removal solution and the stability of the water quality. This enables the washing water containing the adhesive removal solution to be recycled between the two tanks, thereby reducing material consumption and wastewater discharge.

[0004] As a further aspect of the present invention, the installation of the piping system includes: selecting suitable positions at the bottom or side of the degumming tank and the top or side of the degumming tank to ensure that the magnetic pump can effectively extract and transport the washing water containing the degumming agent; ensuring that all connection points are sealed using UPVC direct connectors, elbows, ball valves and internal pressure direct connectors with a diameter of 32 mm to prevent leakage and ensure the chemical resistance and durability of the system.

[0005] As a further aspect of the present invention, the magnetic pump has an automatic start and stop function. It automatically starts when the level of the adhesive removal tank is detected to be lower than a set threshold and automatically stops when the predetermined level is reached, so as to achieve intelligent control.

[0006] As a further embodiment of the present invention, the tap water addition system includes a flow meter and a regulating valve for precisely controlling the amount of tap water added to the washing tank, ensuring that the liquid level is maintained within a preset range, and simultaneously diluting the residual adhesive remover to a suitable concentration.

[0007] As a further aspect of the present invention, a temperature monitoring device is also included to monitor the working temperature in the degumming tank in real time, ensuring that the working temperature is stable at around 80°C, and avoiding additional liquid level loss due to temperature fluctuations.

[0008] As a further aspect of the present invention, it is used to calculate the amount of tap water added to the washing tank. The formula is as follows: ,in This indicates the amount of tap water added to the washing tank. Indicates the target sodium hydroxide or potassium permanganate concentration. This indicates the average concentration of the medicine solution in the initial washing tank. This indicates the concentration of the chemical solution in the adhesive removal tank. The volume of the washing tank is represented by E, the evaporation rate of the chemical solution per unit time is represented by E, and the system leakage rate per unit time is represented by L. This indicates the time interval, i.e., the time between two water replenishment operations, where T represents the actual operating temperature. This indicates the optimal operating temperature, which is typically around 80°C. This is the temperature sensitivity coefficient. The ratio of tap water to adhesive-containing solution is adjusted based on the actual concentration of the chemicals in the washing tank, the chemical evaporation rate, system leaks, and temperature fluctuations. This achieves precise control, ensuring the chemical concentration in the washing tank remains within the optimal range while minimizing resource waste and wastewater discharge. Furthermore, the temperature sensitivity term in the formula... This helps compensate for additional liquid level loss caused by temperature changes, further enhancing the system's adaptability and stability.

[0009] Beneficial effects: This method significantly reduces the frequency of replacing high-concentration adhesive-removing chemicals by pumping wash water containing adhesive remover from the washing tank to replenish the adhesive removal tank, thereby effectively reducing wastewater generation and the cost and complexity of wastewater treatment. Simultaneously, the optimized liquid management system significantly reduces the use of chemicals such as sodium hydroxide and potassium permanganate, saving approximately 16.8 kg of sodium hydroxide and 44.8 kg of potassium permanganate daily, and reducing the discharge of wastewater containing sodium hydroxide and potassium permanganate by 12,000 L. This not only lowers production costs but also improves resource utilization.

[0010] The intelligent control system automatically adjusts the tap water supply based on actual conditions, ensuring a stable liquid level in the washing tank and diluting residual adhesive remover to an appropriate concentration, thus avoiding unnecessary water waste and further improving water conservation. In addition, the temperature monitoring device ensures stable operating temperature, preventing additional liquid level loss due to temperature fluctuations and enhancing the system's environmental performance. The automated and intelligent control system simplifies the operation process, reduces the need for manual intervention, improves work efficiency, ensures production continuity and stability, and ultimately enhances overall production efficiency. Attached Figure Description

[0011] Figure 1 This is a flowchart illustrating the steps of an optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards according to the present invention. Detailed Implementation

[0012] The present invention will be further described in detail below with reference to the embodiments.

[0013] Please see Figure 1 As shown, the specific steps of the optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards according to the present invention are as follows: S1: The target basket on the PTH production line is degummed by the degumming tank and then suspended into the subsequent water washing tank to remove the residual high-concentration degumming solution, which contains sodium hydroxide and potassium permanganate. S2: Install a piping system between the degummed water washing tank and the degumming tank, consisting of a 32 mm diameter UPVC pipe, direct connectors, elbows, ball valves, and internal pressure direct connectors, and connect a 500W power, 220V voltage magnetic pump. One end of the magnetic pump is connected to a suitable position at the bottom or side of the water washing tank, and the other end is connected to a suitable position at the top or side of the degumming tank. S3: Start the magnetic pump and pump the washing water containing the adhesive remover from the washing tank to the adhesive remover tank through the pipeline system. This replenishes the liquid level lost due to evaporation or overflow caused by the working temperature of up to 80°C, and at the same time maintains a stable working liquid volume in the adhesive remover tank. S4: During the process of adding tap water to the water washing tank, the tap water supply is automatically or manually adjusted by the control system to compensate for the amount of water transferred to the adhesive removal tank, maintain the liquid level in the water washing tank, and dilute the residual adhesive removal solution to ensure the cleanliness of the workpiece surface and the stability of the water quality in subsequent processing. S5: Periodically analyze the water in the washing tank to determine whether the concentrations of sodium hydroxide and potassium permanganate meet the predetermined values, and adjust the supply of tap water through the control system based on the analysis results to ensure the effectiveness of the adhesive removal solution and the stability of the water quality. This enables the washing water containing the adhesive removal solution to be recycled between the two tanks, thereby reducing material consumption and wastewater discharge.

[0014] Furthermore, the installation of the piping system includes: selecting suitable locations at the bottom or side of the degumming tank and the top or side of the degumming tank to ensure that the magnetic pump can effectively extract and transport the washing water containing the degumming agent; ensuring that all connection points are sealed using UPVC direct connectors, elbows, ball valves and internal pressure direct connectors with a diameter of 32 mm to prevent leakage and ensure the chemical resistance and durability of the system.

[0015] Furthermore, the magnetic pump has automatic start and stop functions. It automatically starts when the level of the adhesive removal tank is detected to be lower than a set threshold, and automatically stops when the predetermined level is reached, so as to achieve intelligent control.

[0016] As a further embodiment of the present invention, the tap water addition system includes a flow meter and a regulating valve for precisely controlling the amount of tap water added to the washing tank, ensuring that the liquid level is maintained within a preset range, and simultaneously diluting the residual adhesive remover to a suitable concentration.

[0017] Furthermore, it also includes a temperature monitoring device to monitor the operating temperature in the degumming tank in real time, ensuring that the operating temperature is stable at around 80°C, and avoiding additional liquid level loss due to temperature fluctuations.

[0018] Furthermore, it is used to calculate the amount of tap water added to the washing tank. The formula is as follows: ,in This indicates the amount of tap water added to the washing tank. Indicates the target sodium hydroxide or potassium permanganate concentration. This indicates the average concentration of the medicine solution in the initial washing tank. This indicates the concentration of the chemical solution in the adhesive removal tank. The volume of the washing tank is represented by E, the evaporation rate of the chemical solution per unit time is represented by E, and the system leakage rate per unit time is represented by L. This indicates the time interval, i.e., the time between two water replenishment operations, where T represents the actual operating temperature. This indicates the optimal operating temperature, which is typically around 80°C. This is the temperature sensitivity coefficient. The ratio of tap water to adhesive-containing solution is adjusted based on the actual concentration of the chemicals in the washing tank, the chemical evaporation rate, system leaks, and temperature fluctuations. This achieves precise control, ensuring the chemical concentration in the washing tank remains within the optimal range while minimizing resource waste and wastewater discharge. Furthermore, the temperature sensitivity term in the formula... This helps compensate for additional liquid level loss caused by temperature changes, further enhancing the system's adaptability and stability.

[0019] The above description is merely an embodiment of this specification and is not intended to limit this specification. Various modifications and variations can be made to this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of the claims of this application.

Claims

1. An optimized method for reducing material consumption and wastewater discharge in printed circuit board copper plating process, characterized in that, Includes the following steps: S1: The target basket on the PTH production line is degummed by the degumming tank and then suspended into the subsequent water washing tank to remove the residual high-concentration degumming solution, which contains sodium hydroxide and potassium permanganate. S2: Install a piping system consisting of a 32 mm diameter UPVC pipe, direct connectors, elbows, ball valves, and internal pressure direct connectors between the degummed water washing tank and the degummed tank, and connect a 500W power, 220V voltage magnetic pump. One end of the magnetic pump is connected to the bottom or side of the water washing tank, and the other end is connected to the top or side of the degummed tank. S3: Start the magnetic pump and pump the washing water containing the adhesive remover from the washing tank to the adhesive removal tank through the pipeline system to replenish the liquid level lost due to evaporation or overflow; S4: During the process of adding tap water to the washing tank, the tap water supply is automatically adjusted by the control system to compensate for the amount of water transferred to the adhesive removal tank, maintain the liquid level in the washing tank, and dilute the residual adhesive removal solution. S5: Analyze the water in the washing tank to bring the concentrations of sodium hydroxide and potassium permanganate to the predetermined values, and adjust the supply of tap water through the control system based on the analysis results so that the washing water containing the degumming agent can be recycled between the two tanks.

2. The optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards according to claim 1, characterized in that, The piping system includes: connecting the bottom or side of the degumming tank and the top or side of the degumming tank using a piping system to allow the magnetic pump to extract and transport the washing water containing the degumming agent; all connection points of the piping system are sealed using UPVC direct connectors, elbows, ball valves and internal pressure direct connectors with a diameter of 32 mm.

3. The optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards according to claim 1, characterized in that, The magnetic pump has automatic start and stop functions. It automatically starts when the level of the adhesive removal tank is detected to be lower than the set threshold, and automatically stops when the predetermined level is reached.

4. The optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards according to claim 1, characterized in that, The tap water addition system includes a flow meter and a regulating valve to control the amount of tap water added to the washing tank, so that the liquid level is maintained within a preset range, while diluting the residual adhesive remover to a preset concentration.

5. The optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards according to claim 1, characterized in that, It also includes a temperature monitoring device to monitor the working temperature in the degumming tank in real time and ensure that the working temperature is stable at 80℃.

6. The optimized method for reducing material consumption and wastewater discharge in the copper plating process of printed circuit boards according to claim 1, characterized in that, Used to calculate the amount of tap water added to the washing tank. The formula is as follows: ,in This indicates the amount of tap water added to the washing tank. Indicates the target sodium hydroxide or potassium permanganate concentration. This indicates the average concentration of the medicine solution in the initial washing tank. This indicates the concentration of the chemical solution in the adhesive removal tank. The volume of the washing tank is represented by E, the evaporation rate of the chemical solution per unit time is represented by E, and the system leakage rate per unit time is represented by L. This indicates the time interval, i.e., the time between two water replenishment operations, where T represents the actual operating temperature. This indicates the optimal operating temperature, which is typically around 80°C. This is the temperature sensitivity coefficient.

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