A smart monitoring and automatic replenishment system and method for barrel plating bath solution

Abstract

This invention relates to the field of automatic control technology for electroplating processes, and discloses an intelligent monitoring and automatic replenishment system and method for barrel plating bath solutions. The method includes: acquiring bath solution monitoring data, production load data, and replenishment execution data from the previous control cycle to generate chemical change process data of the plating solution; correcting the residual influence of each controlled component concentration based on the chemical change process data to obtain the current concentration determination result; determining the electrochemical consumption and workpiece carry-out loss based on the production load data, and predicting the concentration change trend of each controlled component; and generating channel replenishment control commands and executing the replenishment based on the process setting range and the executable range of the replenishment channel. This invention can reduce the impact of production load fluctuations and replenishment response lag on the stability of the bath solution concentration.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology for electroplating processes, and more specifically, to an intelligent monitoring and automatic replenishment system and method for barrel plating bath solutions. Background Technology

[0002] Barrel plating is a common process for batch electroplating of small parts. During barrel plating, the workpiece is continuously tumbled in a barrel or plating basket and undergoes electrochemical deposition. The concentration stability of the main metal ions, conductive salts, pH adjusting components, and organic additives such as brighteners, leveling agents, and wetting agents in the plating bath directly affects the coating thickness, appearance, adhesion strength, and corrosion resistance. Compared with rack plating or continuous electroplating, barrel plating batches vary significantly in the number of workpieces, total surface area, geometry, and stacking state. Furthermore, carry-over losses occur when workpieces are removed from the bath. Therefore, barrel plating bath composition variations are characterized by large load fluctuations, multiple sources of consumption, and lag in adjustment. If the bath concentration cannot be maintained within the appropriate process range, it can easily lead to fluctuations in coating quality, increased rework rates, and chemical waste.

[0003] In existing technologies, for example, Chinese invention patent application CN107130287A discloses an integrated device for online concentration detection and chemical dosing of electroplating bath solution. This device uses a sampling pump to send the bath solution from the online electroplating tank into a cooling unit. After concentration detection by a unit, a PLC controller controls an automatic chemical dosing unit to add chemicals to the online tank. This solution integrates bath solution sampling, cooling, concentration detection, and chemical dosing into a single device, reducing operational delays caused by manual sampling and dosing, and improving control efficiency to a certain extent. However, this type of online detection and dosing method typically still uses the current detection result as the basis for dosing, and is more of a post-detection compensation control. In situations such as batch switching in barrel plating, changes in workpiece surface area, changes in workpiece liquid volume, or rapid consumption of trace additives, problems such as delayed replenishment, mismatch between replenishment amount and actual consumption, over-filling, or large fluctuations in key components can easily occur.

[0004] Therefore, it is necessary to design an intelligent monitoring and automatic replenishment system and method for barrel plating solutions to solve the problems of lagging solution concentration adjustment, replenishment deviation, and insufficient stability of the solution under the conditions of fluctuating production load, changes in multiple components of the solution, and lag in replenishment response of existing online detection and dosing technologies for electroplating solutions. Summary of the Invention

[0005] In view of this, the present invention proposes an intelligent monitoring and automatic replenishment system and method for barrel plating bath solution, aiming to solve the above problems.

[0006] In one aspect, the present invention proposes a method for intelligent monitoring and automatic replenishment of barrel plating bath solution, comprising: Acquire the bath solution monitoring data and production load data for the current control cycle, read the replenishment execution data recorded in the previous control cycle, and generate the chemical change process data of the plating solution based on the preset composition change relationship of the plating solution; Based on the bath solution monitoring data, the replenishment execution data, and the plating solution chemical change process data, the concentrations of each component to be controlled corresponding to the bath solution monitoring data are corrected for the influence of residual replenishment and the change in detection time lag process to obtain the current concentration determination result. Based on the production load data, the electrochemical consumption and workpiece carry-out loss corresponding to the future production batch are determined. The electrochemical consumption and workpiece carry-out loss are used as load disturbance inputs for concentration change prediction. Combined with the current concentration determination results, the concentration change trend of each controlled component in the future control time domain is predicted. Based on the deviation between the concentration change trend and the process setting range of each controlled component, and in combination with the executable replenishment range of each replenishment channel, the target replenishment amount and replenishment sequence of each replenishment channel in the current control cycle are determined, and channel replenishment control instructions are generated. According to the channel replenishment control command, each replenishment channel is controlled to replenish the corresponding chemical, and the replenishment execution data after each replenishment channel is completed is recorded.

[0007] Furthermore, when generating data on the chemical change process of the plating solution based on the preset compositional change relationship, it includes: Based on the supplementation execution data, determine the supplementation impact of each supplementation channel on each controlled component; Based on the bath solution monitoring data of the current control cycle and the preset composition change relationship of the plating solution, determine the natural change amount of each component to be controlled within the current control cycle; The added influence and the natural variation are grouped according to the corresponding controlled components to obtain the chemical change process data of the plating solution.

[0008] Furthermore, when correcting for the residual replenishment effect and the change in detection time lag process corresponding to the concentration of each controlled component in the bath solution monitoring data, the following are included: Extract the monitoring concentration values ​​corresponding to each component to be controlled from the tank liquid monitoring data, and use the monitoring concentration values ​​as the concentration benchmark values ​​for the current control cycle; Extract the residual replenishment influence and the change in detection time lag process of each component to be controlled from the chemical change process data of the plating solution; Based on the remaining supplementary influence and the change in the detection time lag process, the concentration benchmark value is corrected to obtain the current concentration determination result of each component to be controlled.

[0009] Furthermore, when determining the electrochemical consumption and workpiece carry-out loss corresponding to future production batches based on the aforementioned production load data, the following steps are included: Read the planned electroplating data for future production batches, the total surface area of ​​the workpieces to be plated, and the operating data of the barrel plating basket from the production load data; Based on the planned electroplating data and the electrochemical consumption conversion relationship for each component to be controlled, the electrochemical consumption for future production batches is determined. Based on the total surface area of ​​the workpiece to be plated, the operating data of the barrel plating basket, and the current concentration determination result, the loss amount of each controlled component carried out with the workpiece is determined, and the loss amount of each controlled component carried out with the workpiece is taken as the workpiece carry-out loss amount.

[0010] Furthermore, when determining the loss of each controlled component carried out by the workpiece based on the total surface area of ​​the workpiece to be plated, the operating data of the barrel plating basket, and the current concentration determination result, the following steps are included: Based on the total surface area of ​​the workpiece to be plated and the preset surface wetting relationship, determine the amount of liquid on the workpiece surface corresponding to the surface of the workpiece to be plated; The amount of structural entrainment is determined based on the preset structural entrainment parameters corresponding to the barrel plating basket; Based on the operating data of the barrel plating basket, the amount of liquid carried on the surface of the workpiece and the amount of liquid entrained in the structure are corrected to obtain the amount of liquid carried out of the workpiece for future production batches. Based on the amount of liquid carried out by the workpiece and the current concentration, the loss of each controlled component carried out by the workpiece is determined.

[0011] Furthermore, when predicting the concentration change trends of each controlled component within the future control time domain, this includes: Based on the current concentration determination result, the electrochemical consumption, and the workpiece carry-out loss, the predicted concentration of each component to be controlled in the future control time domain is determined; Based on the difference between the predicted concentration and the process setting range of each component to be controlled, the concentration change trend of each component to be controlled in the future control time domain is generated.

[0012] Furthermore, when determining the target replenishment amount and replenishment timing for each replenishment channel within the current control cycle, the following steps are taken: Based on the concentration change trend, determine the predicted deviation of each controlled component relative to the corresponding process setting range; Based on the predicted deviation, determine the required replenishment amount for each controlled component; Based on the correspondence between each controlled component and each replenishment channel, the required replenishment amount is allocated to the corresponding replenishment channel; Based on the executable replenishment range of each replenishment channel, the required replenishment amount allocated to each replenishment channel is adjusted to obtain the target replenishment amount and replenishment timing of each replenishment channel in the current control cycle, and the channel replenishment control command is generated.

[0013] Furthermore, when allocating the required replenishment amount to the corresponding replenishment channel according to the correspondence between each controlled component and each replenishment channel, the following steps are included: Determine the main supplementation effect of each supplementation channel on the target controlled component, as well as the accompanying effects on non-target controlled components; Based on the main replenishment function, the required replenishment amount of each controlled component is allocated to the corresponding replenishment channel to obtain the initial replenishment amount of each replenishment channel; Based on the accompanying effects, the predicted concentrations of each controlled component after the initial supplementation were verified. When the verification results show that the predicted concentration of any controlled component exceeds the corresponding process setting range, the initial replenishment amount of the replenishment channel related to the controlled component is adjusted to obtain the target replenishment amount of each replenishment channel in the current control cycle.

[0014] Furthermore, after recording the supplementation execution data after each supplementation channel is completed, it also includes: After the production batch is completed, obtain the bath solution retest data, and determine the actual concentration change of each controlled component based on the bath solution retest data; Based on the production load data, electrochemical consumption, workpiece carry-out loss, and replenishment execution data corresponding to the production batch, the predicted concentration change of each controlled component is determined. The actual concentration change is compared with the predicted concentration change to obtain the prediction deviation. When the predicted deviation exceeds the preset deviation range, the preset plating solution composition change relationship is updated based on the predicted deviation.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By acquiring the bath monitoring data, production load data, and replenishment execution data of the previous control cycle, and combining them with the preset bath component change relationship to generate bath chemical change process data, the bath concentration judgment no longer relies solely on the current single monitoring result, but can be corrected by combining the replenishment execution status and bath component change law, for replenishment lag effects and process change effects not yet reflected in the current monitoring value; by correcting the concentration of each controlled component to obtain the current concentration determination result, the reliability of the bath state data on which subsequent concentration prediction is based is improved; and by determining the concentration based on the production load data... The electrochemical consumption and workpiece carry-out loss corresponding to future production batches are used as load disturbance inputs to predict the concentration change trends of each controlled component. This allows the replenishment control to consider the component consumption and carry-out loss caused by future batch production in advance, reducing the adjustment lag caused by replenishing only after the concentration deviates. By combining the concentration change trend, process setting range, and the executable replenishment range of each replenishment channel, the target replenishment amount and replenishment sequence are determined, so that the replenishment action matches the predicted deviation of the bath solution and the execution capability of the replenishment channel. This reduces the impact of replenishment amount deviation and replenishment response lag on the stability of the bath solution, thereby improving the stability of multi-component concentration control of the barrel plating bath solution.

[0016] On the other hand, this application also provides an intelligent monitoring and automatic replenishment system for barrel plating bath solutions, used to implement the above-mentioned intelligent monitoring and automatic replenishment method for barrel plating bath solutions, including: The data acquisition module is used to acquire the bath liquid monitoring data and production load data of the current control cycle, read the replenishment execution data recorded in the previous control cycle, and generate the chemical change process data of the plating solution according to the preset plating solution component change relationship. The concentration determination module is used to correct the residual replenishment effect and the detection time lag process change for the concentration of each component to be controlled corresponding to the bath liquid monitoring data based on the bath liquid monitoring data, the replenishment execution data and the chemical change process data of the plating solution, so as to obtain the current concentration determination result. The concentration prediction module is used to determine the electrochemical consumption and workpiece carry-out loss corresponding to the future production batch based on the production load data. The electrochemical consumption and workpiece carry-out loss are used as load disturbance inputs for concentration change prediction. Combined with the current concentration determination results, the module predicts the concentration change trend of each controlled component in the future control time domain. The replenishment instruction generation module is used to determine the target replenishment amount and replenishment sequence of each replenishment channel in the current control cycle based on the deviation between the concentration change trend and the process setting range of each controlled component, and in combination with the executable replenishment range of each replenishment channel, and generate channel replenishment control instructions. The replenishment execution module is used to control each replenishment channel to replenish the corresponding chemical according to the channel replenishment control command, and to record the replenishment execution data after each replenishment channel has completed replenishment.

[0017] It is understandable that the above-mentioned intelligent monitoring and automatic replenishment system and method for barrel plating bath has the same beneficial effects, and will not be elaborated further here. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of the intelligent monitoring and automatic replenishment method for barrel plating bath provided in an embodiment of the present invention; Figure 2 This is a flowchart of the supplementary channel allocation and review adjustment provided in an embodiment of the present invention; Figure 3 This is a comparison chart of the change of nickel sulfate concentration over time provided in an embodiment of the present invention; Figure 4 This is a comparison chart of the change in brightener concentration over time provided in an embodiment of the present invention; Figure 5 This is a functional block diagram of the intelligent monitoring and automatic replenishment system for barrel plating bath provided in an embodiment of the present invention. Detailed Implementation

[0019] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While the accompanying drawings show exemplary embodiments of the present disclosure, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] See Figure 1-2 As shown, this application proposes a method for intelligent monitoring and automatic replenishment of barrel plating bath solution, including: S100: Obtain the bath liquid monitoring data and production load data of the current control cycle, read the replenishment execution data recorded in the previous control cycle, and generate the chemical change process data of the plating solution according to the preset plating solution component change relationship; S200: Based on the bath solution monitoring data, replenishment execution data, and plating solution chemical change process data, the concentration of each component to be controlled corresponding to the bath solution monitoring data is corrected for the influence of residual replenishment and the change of detection time lag process to obtain the current concentration determination result; S300: Based on production load data, determine the electrochemical consumption and workpiece carry-out loss corresponding to future production batches, use the electrochemical consumption and workpiece carry-out loss as load disturbance inputs for concentration change prediction, and combine the current concentration determination results to predict the concentration change trend of each controlled component in the future control time domain. S400: Based on the deviation between the concentration change trend and the process setting range of each controlled component, and combined with the executable replenishment range of each replenishment channel, determine the target replenishment amount and replenishment sequence of each replenishment channel in the current control cycle, and generate channel replenishment control instructions. S500: Based on the channel replenishment control command, control each replenishment channel to replenish the corresponding chemical, and record the replenishment execution data after each replenishment channel has completed replenishment.

[0021] Specifically, the current control cycle refers to the processing cycle in which the control equipment completes one data reading, concentration determination, concentration prediction, replenishment command generation, and execution record. Its cycle length can be determined based on the plating solution circulation update time, sensor response time, and the minimum stable replenishment time of the metering pump; for example, it can be set to 1 minute, 3 minutes, or 5 minutes. Plating solution monitoring data is used to characterize the current state of the plating solution and may include the concentration of main metal ions, the concentration of organic additives, pH, and temperature. This data can be obtained through an online detection terminal installed on the bypass circulation loop of the electroplating tank. The main metal ion concentration can be detected by an ion-selective electrode or by online titration. pH and temperature can be detected by a pH electrode and a temperature sensor, respectively. The concentration of organic additives can be obtained through online UV-Vis spectroscopy. Specifically, multiple standard solutions with known concentrations of organic additives are prepared, such as low-concentration, target-concentration, and high-concentration standard solutions near the target concentration. The absorbance or spectral characteristic values ​​of each standard solution are collected within a selected wavelength range. Absorbance refers to the degree to which the solution absorbs light at a specific wavelength, and spectral characteristic values ​​are feature data extracted from the spectral curve that characterize changes in organic additive concentration, including absorbance at characteristic absorption peaks, combined absorbance values ​​at multiple wavelengths, or absorption peak areas. The known organic additive concentration of each standard solution is recorded in relation to its corresponding absorbance or spectral characteristic value. Within the current control cycle, the absorbance or spectral characteristic value of the solution to be tested is collected and matched or interpolated with the corresponding records to obtain the current concentration of organic additives in the solution. Production load data is used to characterize the impact of future production batches on the consumption of bath components. It may include the total surface area of ​​the workpiece to be plated, the planned electroplating current, the planned electroplating duration, and the operating data of the barrel plating basket. The total surface area of ​​the workpiece to be plated can be calculated from the surface area of ​​a single workpiece and the batch quantity, or it can be obtained from the process database corresponding to the workpiece model. When the total surface area of ​​the workpiece to be plated is not directly provided, the effective plating area of ​​a single piece can be retrieved according to the workpiece model and multiplied by the batch quantity.

[0022] The replenishment execution data recorded in the previous control cycle refers to the actual replenishment results completed by each replenishment channel within the previous control cycle, including the replenishment channel identifier, the type of replenished chemical, the actual replenishment amount, and the execution status. The actual replenishment amount can be obtained by converting the metering pump's calibrated flow rate and running time, or by verifying the liquid level change or weighing data in the replenishment tank. Specifically, before the replenishment channel is put into use, the metering pump is first calibrated, that is, the metering pump is controlled to run at a fixed operating frequency or fixed opening for a predetermined time, and the volume of replenished liquid output is collected and measured, thereby obtaining the unit time output of the metering pump under the corresponding operating state; during the actual replenishment process, the control equipment records the actual running time of the metering pump and multiplies the unit time output by the actual running time to obtain the actual replenishment amount of the replenishment channel. This replenishment execution data is read because there is a mixing lag after the replenished chemicals enter the electroplating tank. Only a portion of the replenishment action in the previous cycle may have been reflected in the current tank liquid monitoring data, and the remaining portion will continue to affect the tank liquid concentration within the current control cycle. The execution status characterizes the actual completion status of the replenishment channel under the current replenishment command. It can be determined based on the metering pump feedback signal, metering pump runtime, pulse count, and changes in the replenishment tank level or weight. Specifically, the control equipment first determines the target replenishment amount based on the channel replenishment control command, then calculates the actual replenishment amount based on the metering pump's calibrated flow rate, actual runtime, or pulse count, and compares the actual replenishment amount with the target replenishment amount. When the deviation between the actual and target replenishment amounts is within the allowable execution error range, the execution status is recorded as replenishment complete. When the actual replenishment amount is less than the target replenishment amount and the deviation exceeds the allowable execution error range, the execution status is recorded as insufficient replenishment. When the metering pump does not receive a feedback signal, operation is interrupted, the replenishment tank level does not change accordingly, or the actual replenishment amount is abnormally zero, the execution status is recorded as replenishment interrupted or channel abnormal. The allowable execution error range can be determined based on the metering pump's flow rate calibration error and the replenishment liquid metering accuracy; for example, it can be ±2% to ±5% of the target replenishment amount.

[0023] The preset composition change relationship of the plating bath is a composition conversion relationship obtained by calibration based on the target barrel plating process before execution. Specifically, the components to be controlled and their process setting ranges are first determined according to the electroplating process formula. For example, the main metal ions, brighteners, leveling agents, wetting agents, and pH adjustment components are identified as components to be controlled. Then, using a reference bath as the calibration object, predetermined amounts of various supplementary chemicals are added to the reference bath, and the concentration changes of each component to be controlled before and after the addition are detected. The type of supplementary chemical, the amount added, the affected component to be controlled, and the concentration change of the component to be controlled are recorded as a set of calibration records. Based on multiple sets of calibration records under different amounts of supplementation, the concentration change value of the component to be controlled corresponding to a unit amount of supplementation is determined, forming the supplementation effect relationship. For example, after adding a certain amount of brightener replenishment solution to the reference bath, the increase in brightener concentration is measured, and this increase is correlated with the amount of replenishment solution added to obtain the influence of the brightener replenishment channel on the brightener concentration. If a certain main salt replenishment solution, in addition to increasing the main metal ion concentration, also causes a change in pH, the changes in main metal ion concentration and pH value are recorded simultaneously to form the influence relationship of the added chemical on multiple components to be controlled. Simultaneously, under conditions without replenishment, the reference bath is subjected to different temperature ranges, different pH ranges, and different operating times, and the concentration changes of easily variable components such as organic additives are measured. The temperature range, pH range, operating time, components to be controlled, and concentration changes are recorded as natural variation calibration records. Based on multiple sets of calibration records, the natural variation value of the corresponding components to be controlled within a unit operating time is determined to form a natural variation relationship. The above-mentioned replenishment influence relationship and natural variation relationship together constitute the preset plating solution component variation relationship.

[0024] When generating data on the chemical changes in the plating solution, the data is not simply superimposed with the total replenishment effect from the previous control cycle and the total natural changes in the current control cycle. Instead, the remaining effects not yet reflected in the current plating solution monitoring data are determined. Specifically, based on the replenishment execution data from the previous control cycle and the preset plating solution component change relationship, the original replenishment effect of each replenishment channel on each controlled component is first determined. Then, based on the replenishment completion time, the current detection time, and the preset mixing stabilization time, the portion of this original replenishment effect that has been reflected in the current plating solution monitoring data and the portion that has not been reflected are determined, and the unreflected portion is taken as the remaining replenishment effect. The preset mixing stabilization time can be determined through a step replenishment test, i.e., after adding a known amount of replenishment solution to the plating solution, the concentration of the corresponding controlled component is continuously measured. When the concentration change in multiple consecutive detection cycles is less than the allowable detection error, the time from the completion of replenishment to that moment is taken as the mixing stabilization time.

[0025] Because online detection typically involves a response time from sampling and signal acquisition to outputting monitoring results, the current bath solution monitoring data may correspond to the bath solution state at the sampling time, rather than the state at the time the control equipment performs calculations. Therefore, based on the current bath solution temperature, pH, and preset compositional variation relationships, the detection time lag process change of each controlled component between the sampling time and the current control calculation time is determined. The detection time lag process change is used to characterize the component changes caused by the natural decay of organic additives, temperature changes, or pH changes during the detection time lag period; when the online detection terminal's response time is negligible relative to the current control cycle, the detection time lag process change can be taken as zero. The remaining replenishment influence and the detection time lag process change are merged according to the corresponding controlled components to obtain the plating solution chemical change process data.

[0026] Using the monitored concentration values ​​of each controlled component in the plating bath data as the concentration baseline, the baseline values ​​are corrected by utilizing the residual replenishment effect and the process change during the detection lag in the chemical change process data of the plating bath, thus obtaining the current concentration determination result. In other words, the current concentration determination result is not a full repetition correction of the real-time monitoring value, but rather a supplement to the current monitoring value to include the replenishment lag effect and the process change effect during the detection lag period that have not yet been reflected. For example, if the current monitored concentration of the brightener is 4.80 mL / L, the original addition effect of the brightener addition action in the previous control cycle was an increase of 0.40 mL / L, the preset mixing and stabilization time is 4 min, only 2 min has passed from the completion of the addition to the current detection time, and it is determined from the mixing calibration results that the current monitored concentration value has reflected 50% of the addition effect, then the remaining addition effect is 0.40 mL / L × (1 - 50%) = 0.20 mL / L; if the time between the detection sampling time and the current control calculation time is 1 min, and the natural change value of the brightener per unit time at the current temperature and pH is a decrease of 0.005 mL / L per minute, then the change in the detection time lag process is a decrease of 0.005 mL / L, and the current concentration of the brightener is determined to be 4.80 mL / L + 0.20 mL / L - 0.005 mL / L = 4.995 mL / L.

[0027] When determining the electrochemical consumption for future production batches, it is based on the planned electroplating current, planned electroplating duration, and the electrochemical consumption conversion relationship. This conversion relationship can be calibrated based on the current efficiency in the electroplating process, the target metal type, and the actual concentration decrease corresponding to the unit charge throughput in historical batches. When determining the workpiece carry-out loss, it is based on the total surface area of ​​the workpiece to be plated, the operating data of the barrel plating basket, and the current concentration determination result. This reflects the loss of bath components caused by workpiece surface wetting, workpiece gap entrainment, and barrel plating basket structure entrainment. By using the electrochemical consumption and workpiece carry-out loss as load disturbance inputs, the concentration change trend of each controlled component in the future control time domain can be predicted based on the current concentration determination result.

[0028] The process setting range is determined by the electroplating process documents, product quality requirements, and qualified trial production data, including the target concentration, upper and lower allowable limits. The executable replenishment range for each replenishment channel is determined by the metering pump's rated flow rate, minimum stable output, single allowable replenishment amount, replenishment interval, and replenishment solution concentration. When determining the channel replenishment control command, first assess the deviation of each controlled component from the process setting range based on concentration change trends, then determine the corresponding target replenishment amount, and finally determine the replenishment sequence based on the executable replenishment range of each replenishment channel. The channel replenishment control command must include at least the replenishment channel identifier, corresponding chemical type, target replenishment amount, and replenishment sequence. After replenishment is completed, record the actual replenishment amount and execution status of each replenishment channel as input data for concentration correction and prediction in the next control cycle, thus forming a continuous closed-loop control.

[0029] Specifically, when determining the replenishment impact of each replenishment channel on each controlled component based on the replenishment execution data, the replenishment channel identifier and actual replenishment amount in the replenishment execution data are first read. Based on the replenishment channel identifier, the corresponding chemical type and the controlled component affected by the chemical type are found in the preset plating solution component change relationship. Then, the unit replenishment amount concentration change value of the chemical type on the corresponding controlled component is read. The unit replenishment amount concentration change value is obtained by pre-calibration and is used to represent the concentration change of the corresponding controlled component after a unit volume or unit mass of replenishment chemical is added to the current effective tank solution volume. Then, the actual replenishment amount is multiplied by the unit replenishment amount concentration change value to obtain the original replenishment impact of the replenishment channel on the corresponding controlled component. For example, if the brightener replenishment channel actually replenishes 20 mL of brightener in the previous control cycle, and it is pre-calibrated that each 1 mL of this replenishment increases the brightener concentration in the current effective tank volume by 0.02 mL / L, then the original replenishment effect of this brightener replenishment channel on brightener formation is an increase of 0.4 mL / L. If a certain main salt replenishment solution, in addition to increasing the concentration of main metal ions, also causes a change in pH value, then the unit replenishment change values ​​of the main salt replenishment solution on main metal ions and pH are read respectively, and the corresponding original replenishment effect is calculated respectively.

[0030] When determining the natural variation of each controlled component within the current control cycle based on the bath monitoring data and the preset composition change relationship of the plating solution, the following steps are taken: First, read the current bath temperature, current pH, and current control cycle duration from the bath monitoring data. Then, based on the component identification, find the natural variation value per unit time of the controlled component in the preset composition change relationship for that component within the corresponding temperature and pH ranges. Subsequently, multiply the natural variation value per unit time by the current control cycle duration to obtain the original natural variation of the controlled component within the current control cycle. For example, if the current bath temperature is 55℃ and the pH is 4.5, and the pre-set plating solution component change relationship records that the natural change value of the brightener per unit time in this temperature and pH range is a decrease of 0.005 mL / L per minute, and the current control cycle is 3 minutes, then the original natural change of the brightener in this control cycle is a decrease of 0.015 mL / L. If the current temperature or pH is between two calibration ranges, then the natural change value per unit time corresponding to the adjacent calibration range is first interpolated, and then multiplied by the current control cycle duration to obtain the original natural change value.

[0031] When merging the added influence and natural variation according to the corresponding controlled components, the data from different components and units are not directly mixed and added together. Instead, a process change record is first established based on the controlled component identifier. Each process change record includes at least the controlled component identifier, the original added influence, the original natural variation, the dimensionless added influence value, the dimensionless natural variation value, and the total process change value. For the same controlled component, the added influence and natural variation are first ensured to use the same units; for example, main metal ions are uniformly represented as g / L or mg / L, organic additives as mL / L or mg / L, and pH adjustment results as pH value changes. Then, a dimensionless reference value is determined based on the process setting range of the controlled component. The dimensionless reference value can be the difference between the upper and lower limits of the process for the controlled component, or it can be the allowable deviation value of the process. The original added influence and the original natural variation are divided by the corresponding dimensionless reference value to obtain the dimensionless added influence value and the dimensionless natural variation value.

[0032] After dimensionless processing, the dimensionless supplementary influence value and dimensionless natural change value corresponding to the same controlled component are accumulated according to the direction of absolute concentration change to obtain the total process change value of the controlled component. Specifically, changes that increase the concentration of the corresponding controlled component are recorded as concentration increase direction, and changes that decrease the concentration of the corresponding controlled component are recorded as concentration decrease direction; when the controlled component is a pH adjustment component, the corresponding direction of change is pH increase or decrease. It should be noted that the total process change value is used to represent the relative degree of change of the controlled component within the current control period. It is mainly used for comparing the degree of deviation between different controlled components, determining supplementary priority, or normalizing the process change record, and is not directly used as the actual concentration correction amount to replace the original change amount.

[0033] Meanwhile, the original addition effect and the original natural variation are retained for subsequent correction of the actual concentration values ​​in the tank solution monitoring data. The original addition effect and the original natural variation only participate in concentration correction when the same controlled component is used and the same unit of measurement is used; the original variations between different controlled components are not cumulative. For example, the original variation of the main metal ion is expressed in g / L or mg / L and is only used to correct the monitored concentration value of the main metal ion; the original variation of the brightener is expressed in mL / L or mg / L and is only used to correct the monitored concentration value of the brightener; the pH adjustment result is expressed as the pH value change and is only used to correct the pH-related monitoring results.

[0034] For example, if the process setting range for the brightener is 4.5 mL / L to 5.5 mL / L, then the dimensionless reference value is 1.0 mL / L. If the original replenishment effect of the brightener in a certain control period is an increase of 0.4 mL / L, and the original natural change is a decrease of 0.015 mL / L, then the dimensionless replenishment effect value is +0.4, the dimensionless natural change value is -0.015, and the total process change value after aggregation is +0.385. This total process change value only represents the normalized change of the brightener relative to its process setting range in the current control period; when correcting the brightener monitoring concentration value, the original replenishment effect of 0.4 mL / L and the original natural change of 0.015 mL / L are still used. Whether this change makes the brightener concentration closer to the target concentration needs to be determined in the subsequent prediction deviation judgment in combination with the current concentration of the brightener, the target concentration, and the allowable upper and lower limits. The process change records corresponding to each controlled component together constitute the chemical change process data of the plating solution.

[0035] Specifically, when extracting the monitoring concentration values ​​corresponding to each controlled component, the corresponding real-time monitoring results are first found in the tank solution monitoring data according to the component's identifier. These real-time monitoring results are then uniformly converted to the preset concentration units for that controlled component; for example, the concentration of main metal ions is uniformly set to g / L or mg / L, the concentration of organic additives to mL / L or mg / L, and the pH adjustment result to pH value or pH change. After unit unification, the monitoring concentration value of each controlled component within the current control cycle is used as the concentration baseline value. The concentration baseline value represents the apparent monitoring concentration obtained by the online detection terminal within the current control cycle. It already reflects some of the actual changes in the tank solution at the detection time, but may not fully reflect the mixing lag effect of the replenishment action in the previous control cycle, as well as the process changes that occurred between the detection sampling time and the current control calculation time.

[0036] When extracting the residual replenishment influence and the change in detection lag time from the chemical change process data of the plating solution, matching is performed according to the identifier of the controlled component. That is, the residual replenishment influence and the change in detection lag time are extracted for the main metal ion, for the brightener, and for the pH adjustment component. If the chemical change process data of the plating solution stores both the original change and the dimensionless change value, the original residual replenishment influence and the original change in detection lag time, which have the same unit as the concentration reference value, are preferentially used when correcting the concentration reference value. The dimensionless change value is used to compare the degree of deviation between different controlled components or to determine the priority of subsequent replenishment.

[0037] When correcting the concentration baseline value based on the remaining supplementary influence and the change in the detection time lag process, the correction is made only on the portion of the concentration baseline value that has not yet been reflected in the baseline value, rather than directly adding all the supplementary influence and all natural changes from the previous control cycle. Specifically, the remaining influence that increases the concentration of the controlled component or brings it closer to the process set range is used as the positive correction amount, while the remaining influence that decreases the concentration of the controlled component, dilutes it, consumes it, or moves it away from the process set range is used as the negative correction amount. The concentration baseline value is added to the positive correction amount, and the negative correction amount is subtracted to obtain the current concentration determination result of the controlled component.

[0038] For example, if the current brightener concentration in the bath solution monitoring data is 4.80 mL / L, the original addition effect of the brightener replenishment action in the previous control cycle was an increase of 0.40 mL / L, the preset mixing stabilization time is 4 min, 2 min has passed from the completion of replenishment to the current detection time, and according to the mixing calibration results, the current monitoring concentration value has reflected 50% of the replenishment effect, then the remaining replenishment effect is 0.40 mL / L × (1 - 50%) = 0.20 mL / L. If the time between the detection sampling time and the current control calculation time is 1 min, and the natural change value of the brightener at the current temperature and pH is a decrease of 0.005 mL / L per minute, then the change during the detection time lag process is a decrease of 0.005 mL / L. At this point, using 4.80 mL / L as the concentration baseline, the remaining added influence is added to the concentration baseline as a positive correction, and the change in concentration due to the detection lag is subtracted from the concentration baseline as a negative correction. The current concentration of the brightener is then determined as: 4.80 mL / L + 0.20 mL / L - 0.005 mL / L = 4.995 mL / L. This current concentration determination is used for subsequent concentration trend prediction.

[0039] Specifically, the planned electroplating data can include the planned electroplating current, the planned electroplating duration, and the current efficiency parameters under the corresponding process. The total surface area of ​​the workpiece to be plated can be obtained by multiplying the number of workpieces in the future production batch by the effective plating area of ​​a single workpiece, or it can be obtained by reading the total surface area record corresponding to the workpiece model in the process database. The barrel plating basket operation data can include the barrel plating basket model, the barrel plating basket rotation speed, the planned rotation duration, or the cumulative number of rotations. After reading the above data, the data units should be standardized, for example, the electroplating duration should be standardized to minutes or seconds, the total surface area of ​​the workpiece to be plated should be standardized to square meters, and the cumulative number of rotations of the barrel plating basket should be standardized to the number of rotations, so as to facilitate subsequent conversions.

[0040] When determining electrochemical consumption based on planned electroplating data, firstly, the charge throughput corresponding to the future production batch is determined based on the planned electroplating current and planned electroplating duration. This is achieved by multiplying the planned electroplating current by the planned electroplating duration to obtain the current-time integral value. Then, based on the electrochemical consumption conversion relationship for each controlled component, the current-time integral value is converted into the electrochemical consumption of the corresponding controlled component. The electrochemical consumption conversion relationship can be obtained through calibration in a trial production batch. Specifically, under known electroplating current, known electroplating duration, and known tank liquid volume, the concentration decrease of the main metal ions or related controlled components before and after electroplating is measured. The concentration decrease or mass consumption corresponding to the unit current-time integral value is used as the electrochemical consumption conversion value for that controlled component. For example, if the planned electroplating current is 100A and the planned electroplating duration is 30min, and the pre-calibrated unit current time consumption value of a certain main metal ion is 0.02g per A·min, then the electrochemical consumption of the main metal ion in this future production batch is 100×30×0.02g, or 60g; if the concentration reduction is required, it is then calculated based on the effective tank liquid volume of the electroplating tank.

[0041] When determining the workpiece carry-out loss based on the total surface area of ​​the workpiece to be plated, the operating data of the barrel plating basket, and the current concentration, the carry-out liquid volume for future production batches is first determined based on the total surface area of ​​the workpiece and the entrainment parameters of the barrel plating basket structure. The carry-out liquid volume can be determined according to the following relationship: multiply the total surface area of ​​the workpiece to be plated by the surface wetting coefficient to obtain the workpiece surface wetting liquid volume; add the workpiece surface wetting liquid volume to the basic entrainment volume of the barrel plating basket structure to obtain the basic carry-out liquid volume; then correct the basic carry-out liquid volume based on the cumulative number of barrel plating basket rotations and the dynamic enhancement coefficient to obtain the workpiece carry-out liquid volume. That is, the workpiece carry-out liquid volume can be expressed as: Workpiece carry-out liquid volume = (Surface wetting coefficient × Total surface area of ​​the workpiece to be plated + Basic entrainment volume of the barrel plating basket structure) × (1 + Dynamic enhancement coefficient per rotation × Effective cumulative number of rotations).

[0042] The surface wetting coefficient represents the amount of liquid carried per unit workpiece surface area and can be calibrated by weighing. The basic amount of liquid carried by the barrel plating basket structure represents the basic amount of liquid carried by the basket when it is removed in a single batch due to gaps in the basket's pores, corners, or structural gaps. This can be obtained through liquid carrying tests under empty basket or standard loading conditions. The dynamic enhancement coefficient per revolution represents the correction ratio of the basic liquid carried out per revolution of the barrel plating basket, with the unit being 1 / revolution. The dynamic enhancement coefficient per revolution × the effective cumulative number of revolutions is the dimensionless correction amount. The effective cumulative number of revolutions is the number of revolutions used for carry-out correction, which is determined based on the barrel plating basket's rotation speed and running time and is limited to a preset calibration range. The preset calibration range can be determined based on liquid carry-out tests. For example, by measuring the amount of liquid carried out after removing the workpiece and the barrel plating basket at different cumulative revolutions, when the cumulative revolutions continue to increase and the change in liquid carry-out tends to stabilize, the corresponding number of revolutions is taken as the upper limit of calibration. If the actual cumulative number of rotations exceeds the calibration limit, the calibration limit shall be taken as the effective cumulative number of rotations; if the rotation speed, draining time or loading method of the barrel plating basket exceeds the calibration conditions, the dynamic enhancement coefficient per rotation shall be recalibrated or the parameter table under the corresponding working conditions shall be adopted.

[0043] After obtaining the amount of liquid carried out by the workpiece, the loss of each controlled component carried out with the workpiece is determined based on the current concentration determination result. Specifically, the amount of liquid carried out by the workpiece is multiplied by the current concentration determination result of the corresponding controlled component to obtain the loss of that controlled component carried out with the workpiece. For example, if the amount of liquid carried out by the workpiece in a future production batch is determined to be 2L according to the above relationship, and the concentration of a certain main metal ion in the current concentration determination result is 50g / L, then the loss of that main metal ion carried out with the workpiece is 2×50g, or 100g; if the current brightener concentration is 5mL / L, then the loss of that brightener carried out with the workpiece is 2×5mL, or 10mL. The total workpiece carry-out loss is composed of the loss of each controlled component carried out with the workpiece.

[0044] Specifically, the preset surface wetting relationship is used to represent the correspondence between the surface area of ​​the workpiece to be plated and the amount of liquid carried on the workpiece surface. This can be obtained through liquid carrying calibration before execution. During calibration, a standard workpiece with a known surface area or the actual workpiece to be plated is selected, and an immersion test is conducted under the same conditions as production: bath solution, immersion time, rack lifting speed, and draining time. The mass or volume difference of the workpiece before and after removal is recorded, and this difference is converted into the amount of liquid carried on the workpiece surface. Then, the amount of liquid carried on the workpiece surface is divided by the corresponding workpiece surface area to obtain the liquid carrying coefficient per unit surface area. In subsequent production batches, the amount of liquid carried on the workpiece surface corresponding to the workpiece to be plated is determined by multiplying the total surface area of ​​the workpiece to be plated by the liquid carrying coefficient per unit surface area. For example, if the liquid carrying coefficient per unit surface area obtained from calibration is 0.08 L / m², and the total surface area of ​​the workpiece to be plated in a future production batch is 15 m², then the amount of liquid carried on the workpiece surface is 15 × 0.08 L, or 1.2 L.

[0045] The preset structural entrainment parameters represent the basic entrainment volume formed by the barrel plating basket's own structure when the plating bath is removed. This parameter is related to the barrel plating basket model, opening structure, corner structure, internal baffles of the basket body, and the workpiece loading state. To determine the structural entrainment volume, first read the barrel plating basket model, then look up the corresponding structural entrainment basic volume in the pre-calibrated barrel plating basket structural parameter table. This structural entrainment basic volume can be obtained through an empty basket liquid-carrying test or a standard loaded liquid-carrying test. That is, without considering the liquid-carrying volume on the workpiece surface, measure the volume of bath liquid entrained by the basket structure after the barrel plating basket is removed from the bath and the preset draining time is completed. For example, if the structural entrainment basic volume of a certain model of barrel plating basket is 0.5L under standard lifting speed and 30s draining time, then 0.5L is taken as the structural entrainment volume corresponding to that barrel plating basket.

[0046] When correcting the liquid carry-out amount on the workpiece surface and the structural entrainment amount based on the barrel plating basket's operating data, the cumulative number of barrel plating basket rotations or the barrel plating basket's rotation speed and operating time can be read, and the basic liquid carry-out amount can be corrected according to the dynamic enhancement coefficient. Specifically, first, the liquid carry-out amount on the workpiece surface and the structural entrainment amount are added together to obtain the basic liquid carry-out amount; then, the carry-out enhancement ratio is determined based on the cumulative number of barrel plating basket rotations and the dynamic enhancement coefficient; finally, the basic liquid carry-out amount is multiplied by the carry-out enhancement ratio to obtain the workpiece liquid carry-out amount corresponding to the future production batch.

[0047] Specifically, the future control time domain refers to the time range from the start of the current control cycle for concentration prediction. Its length can be determined based on the processing time of a single batch of barrel plating, the bath solution circulation and mixing time, and the replenishment response lag time. For example, it can be the duration of a future barrel plating batch, or 30 minutes or 60 minutes in the future. When determining the predicted concentration, the current concentration determination result is first used as the starting concentration of the future control time domain. Then, based on the execution time of the future production batch within the future control time domain, the electrochemical consumption and workpiece carry-out loss are allocated to the corresponding prediction period. If the future control time domain contains only one production batch, the electrochemical consumption and workpiece carry-out loss corresponding to that production batch are directly used as the basis for concentration decrease within that time domain. If the future control time domain contains multiple production batches, the electrochemical consumption and workpiece carry-out loss corresponding to each batch are applied sequentially to the corresponding prediction period according to the start and end times of each production batch.

[0048] For each component to be controlled, the electrochemical consumption and workpiece carry-out loss are first converted to a concentration unit consistent with the current concentration determination result of that component; for example, the main metal ion can be uniformly converted to g / L or mg / L, and organic additives can be uniformly converted to mL / L or mg / L. Then, based on the current concentration determination result, the decrease in concentration corresponding to electrochemical consumption and the decrease in concentration corresponding to workpiece carry-out during the corresponding prediction period are subtracted to obtain the predicted concentration for that prediction period. For example, if the current concentration determination result of a certain main metal ion is 50 g / L, and the electrochemical consumption corresponding to the future production batch is converted to a concentration decrease of 1.2 g / L, and the workpiece carry-out loss is converted to a concentration decrease of 0.5 g / L, then the predicted concentration of the main metal ion at the end of the prediction period is 50 g / L - 1.2 g / L - 0.5 g / L = 48.3 g / L.

[0049] If there are supplementary actions recorded in the previous control cycle but not yet fully effective, the concentration increase formed by these actions can be added to the corresponding prediction period based on the remaining impact of the supplementary actions. Supplementary actions that have not yet fully taken effect refer to those that were generated and issued in the previous control cycle and have been executed or are being executed, but have not been fully reflected in the current concentration determination result due to lag in tank solution mixing, pipeline circulation, or detection response. The target supplementary amount not yet generated in the current control cycle is not included in the predicted concentration calculation in this step. This step first predicts the tank solution concentration change as if there are no new supplementary actions in this cycle to determine whether a channel supplementary control command needs to be generated in subsequent steps.

[0050] When generating concentration change trends based on the difference between the predicted concentration and the process setting range of each controlled component, the process setting range corresponding to each controlled component is first read. The process setting range includes the target concentration, the upper limit of allowable concentration, and the lower limit of allowable concentration. After the target barrel plating process is determined, it is jointly determined based on the electroplating process formula, the bath maintenance standard, and the trial production verification results. Specifically, the recommended concentration given in the electroplating process formula is first used as the initial value of the target concentration; then, multiple test concentration points are set near this initial value of the target concentration, and test plating is carried out at each point. The coating thickness, appearance brightness, bonding strength, corrosion resistance, and defects such as scorching, fogging, pinholes, or brittleness are detected. The concentration range that can make the coating quality meet the product requirements and achieve continuous and stable production is determined as the qualified concentration range. Subsequently, combined with bath fluctuations, sensor detection errors, and replenishment hysteresis, the upper limit of allowable concentration and the lower limit of allowable concentration are narrowed down within the qualified concentration range, and the position with higher coating quality stability in the qualified concentration range is determined as the target concentration. For example, for a brightener, the recommended concentration can be determined as 5.0 mL / L based on the supplier's formulation or process documentation. Then, trial plating can be performed at test concentrations of 4.5 mL / L, 5.0 mL / L, and 5.5 mL / L. If insufficient brightness occurs below 4.5 mL / L, or increased brittleness or excessive organic matter risk occurs above 5.5 mL / L, then 4.5 mL / L to 5.5 mL / L can be used as the process setting range, with 5.0 mL / L as the target concentration. For main metal ions, the corresponding target concentration, upper and lower allowable limits can be determined based on the test results of deposition rate, coating thickness uniformity, and current efficiency. Then, the predicted concentration for each prediction period is compared with the corresponding process setting range to determine whether the controlled component is within the range, close to the lower limit, below the lower limit, or at risk of exceeding the upper limit. To facilitate comparisons between different controlled components, the difference between the predicted concentration and the process set range can be divided by the width of the process set range to obtain a dimensionless deviation value. For example, if the brightener process set range is 4.5 mL / L to 5.5 mL / L and the predicted concentration is 4.6 mL / L, then the difference from the lower limit is 0.1 mL / L, corresponding to a dimensionless margin of 0.1 ÷ 1.0 = 0.1. The predicted concentration, deviation direction, deviation amount, and expected deviation time for each prediction period together constitute the concentration change trend of each controlled component within the future control time domain.

[0051] Specifically, when determining the predicted deviation, the predicted concentrations of each controlled component in the future control time domain are first read from the concentration change trend. Then, the predicted concentrations are compared with the corresponding process setting range for that controlled component. The process setting range includes the target concentration, the upper allowable limit, and the lower allowable limit, which can be determined based on the electroplating process formula, trial production verification results, and product quality inspection results. If the predicted concentration is lower than the lower allowable limit, the difference between the target concentration and the predicted concentration is taken as the predicted deviation of the controlled component. If the predicted concentration is not lower than the lower allowable limit, but the difference between it and the lower allowable limit is less than the preset warning margin, the difference between the target concentration and the predicted concentration is taken as the pre-addition deviation. If the predicted concentration is within the process setting range and not close to the lower allowable limit, the predicted deviation of the controlled component is recorded as zero. The preset warning margin can be determined based on the width of the process setting range, for example, 10% to 20% of the difference between the upper and lower allowable limits, or it can be calibrated based on the average time required for the controlled component to go from close to the lower allowable limit to below the lower allowable limit in historical batches.

[0052] When determining the required replenishment amount based on the predicted deviation, first convert the predicted deviation into the concentration difference that needs to be restored, and then combine this with the effective tank volume of the electroplating bath and the concentration of the effective component of the replenishing chemicals for further calculation. For main metal ions or organic additives, the required replenishment amount can be determined according to the concentration difference, the effective tank volume, and the content of the effective component in the replenishing solution; for pH adjustment components, it can be determined based on the pH value change corresponding to the unit replenishment amount obtained from titration tests. For example, if the target concentration of brightener is 5.0 mL / L and the predicted concentration is 4.6 mL / L, then the predicted deviation is 0.4 mL / L; if the effective tank volume of the electroplating bath is 1000 L, and each mL of brightener replenishing solution, after conversion based on the effective component, can provide 1 mL of effective brightener, then the required replenishment amount is 0.4 × 1000 = 400 mL.

[0053] The correspondence between each controlled component and each replenishment channel refers to the mapping relationship between each controlled component and the replenishment channel that can adjust the concentration of that controlled component. This correspondence is determined before execution based on the type of chemical replenishment tank connected to the replenishment channel, the effective components of the replenishment solution, and the preset compositional changes of the plating solution, and is stored in the form of a correspondence table. The correspondence table includes at least the controlled component identifier, replenishment channel identifier, replenishment solution name, concentration change value corresponding to a unit replenishment amount, and whether it is a primary replenishment channel. For example, primary metal ions correspond to primary salt replenishment channels, brighteners correspond to brightener replenishment channels, leveling agents correspond to leveling agent replenishment channels, and pH adjusting components correspond to acid or alkali replenishment channels. If a composite additive replenishment solution contains both brightener and wetting agent, then the replenishment channel establishes a correspondence with both brightener and wetting agent, and records the change in brightener and wetting agent concentrations per unit replenishment amount, respectively.

[0054] When allocating the required replenishment amount to the corresponding replenishment channel, the control equipment first searches the correspondence table for the replenishment channel that can adjust the component to be controlled based on the component identifier. If a component to be controlled corresponds to only one main replenishment channel, the required replenishment amount of the component to be controlled is converted into the required replenishment volume of the channel according to the unit replenishment concentration change value of the replenishment amount. If a component to be controlled corresponds to multiple replenishment channels, the required replenishment amount of the component to be controlled is allocated to multiple replenishment channels according to the unit replenishment concentration change value of each replenishment channel, the effective component concentration of the replenishment liquid, historical execution stability, or preset allocation ratio. For example, if the required replenishment amount of brightener is 0.4 mL / L, and the correspondence table records that each 1 mL of replenishment liquid added to the brightener replenishment channel can increase the brightener concentration at the current effective tank liquid volume by 0.002 mL / L, then the required replenishment volume of the brightener replenishment channel is 0.4 ÷ 0.002 = 200 mL.

[0055] When adjusting based on the executable replenishment range of each replenishment channel, first read the minimum stable output, maximum output, single allowable replenishment amount, replenishment interval, and allowable replenishment rate of the metering pump corresponding to that replenishment channel; these parameters can be determined by the metering pump flow rate calibration, replenishment concentration, tank liquid mixing time, and process safety requirements. If the required replenishment amount allocated to a certain replenishment channel is between the minimum stable output and the maximum allowable replenishment amount for the current control cycle, then that required replenishment amount is taken as the target replenishment amount for the current control cycle. If the required replenishment amount allocated to a certain replenishment channel is lower than the minimum stable output, then first check whether the predicted concentration of each controlled component is still within the corresponding process setting range after execution according to the minimum stable output of the replenishment channel. If the check result shows that the predicted concentration of each controlled component is within the corresponding process setting range, then execute according to the minimum stable output, and record the difference between the minimum stable output and the required replenishment amount as the excess replenishment amount. The excess replenishment amount is used to offset the required replenishment amount in subsequent control cycles. If the check result shows that the predicted concentration of any controlled component will exceed the corresponding process setting range, then the replenishment requirement that is lower than the minimum stable output will not be executed in the current control cycle. Instead, the required replenishment amount will be written into the replenishment amount record of subsequent control cycles, and executed after the cumulative amount in subsequent control cycles is not lower than the minimum stable output.

[0056] If the required replenishment amount allocated to a certain replenishment channel exceeds the maximum allowable replenishment amount for the current control cycle, the maximum allowable replenishment amount for the current control cycle is determined as the target replenishment amount for the current control cycle, and the excess is recorded in the replenishment amount record for subsequent control cycles. The replenishment sequence is determined based on the predicted time of the deviation, the mixing stabilization time of the replenishment solution, and the order of addition of different chemicals, ensuring that the replenishment action is completed and takes effect before the predicted concentration falls below the lower limit of allowable concentration. When the predicted deviation cannot be completely eliminated within the current control cycle due to limitations of the maximum replenishment amount, replenishment interval, or allowable addition rate of the replenishment solution, a restricted replenishment control instruction and an over-limit risk warning are generated, and the unmet replenishment amount is carried over to the next control cycle.

[0057] The resulting target replenishment amount and replenishment timing are used to generate channel replenishment control instructions. These instructions include at least the channel identifier, target replenishment amount, replenishment start time, and replenishment duration or number of replenishment cycles. For example, if a brightener channel requires 400 mL of replenishment solution, but the maximum allowable replenishment amount for that channel in the current control cycle is 250 mL, then the target replenishment amount for the current control cycle is determined to be 250 mL, and the remaining 150 mL is used as the replenishment amount for subsequent control cycles. If a deviation is predicted to occur after 10 minutes, and the mixing and stabilization time of the replenishment solution is 3 minutes, then the replenishment timing is set to complete the corresponding replenishment at least 3 minutes before the deviation occurs.

[0058] Specifically, the primary replenishment effect of each replenishment channel on the target controlled component, and its accompanying effects on non-target controlled components, can be determined based on the pre-defined plating solution composition change relationship: replenishment channel—chemical type—affected controlled component—unit replenishment amount change. The target controlled component refers to the component that the replenishment channel is primarily used to adjust; for example, the target controlled component of the main salt replenishment channel is the main metal ion, and the target controlled component of the brightener replenishment channel is the brightener. Non-target controlled components refer to other components that the replenishment channel may simultaneously affect when replenishing the target component. For example, acidic main salt replenishment solution may decrease the pH while increasing the main metal ion concentration, and composite organic additive replenishment solution may increase the concentration of wetting agent or leveling agent while increasing the brightener concentration. When determining the main supplementation effect, read the unit supplementation change value of the supplementation channel for the target controlled component; when determining the accompanying effect, read the unit supplementation change value of the supplementation channel for the non-target controlled component. If there is no corresponding change record for a certain non-target controlled component, the accompanying effect of the supplementation channel on the non-target controlled component is recorded as zero.

[0059] When allocating the required supplementation amount based on the main supplementation effect, first determine the required supplementation amount for each controlled component, and then find the supplementation channel that can supplement that controlled component. If a controlled component corresponds to only one supplementation channel, the required supplementation amount for that controlled component is directly allocated to that supplementation channel; if a controlled component corresponds to multiple supplementation channels, the allocation is based on the concentration of the active ingredient in each supplementation channel, the change in unit supplementation amount, and the preset allocation ratio. Specifically, the required supplementation amount for the controlled component can be divided by the change in unit supplementation amount for the corresponding supplementation channel to obtain the initial supplementation amount for that channel.

[0060] When verifying based on accompanying effects, it's not simply a matter of checking whether the target controlled component has been replenished. Instead, the initial replenishment amount for each replenishment channel is substituted into its corresponding main replenishment action and accompanying effects to calculate the predicted concentration of each controlled component after the initial replenishment amount is applied. Specifically, for each replenishment channel, the initial replenishment amount is multiplied by the unit replenishment change value for both the target and non-target controlled components of that channel to obtain the predicted change for each controlled component. Then, the predicted changes for the same controlled component from different replenishment channels are summarized and added to the original predicted concentration of the controlled component to obtain the verification predicted concentration after the initial replenishment amount. If the verification predicted concentrations are all within the corresponding process setting range, the initial replenishment amount is taken as the target replenishment amount.

[0061] When the verification results show that the predicted concentration of any controlled component exceeds the corresponding process setting range, first identify the supplementary channel that caused the exceedance, i.e., find the supplementary channel that has a primary supplementary effect or accompanying effect on the controlled component exceeding the limit; then prioritize adjusting the initial supplementary amount of the supplementary channel that has an accompanying effect on the controlled component exceeding the limit. The adjustment method can be to reduce the initial supplementary amount of the supplementary channel, postpone part of the supplementary amount to the next control cycle, or transfer the required supplementary amount to other supplementary channels with less accompanying effect on the non-target controlled component. For example, if the initial supplementary amount of the main salt supplementary channel can bring the main metal ion back to the target concentration, but the verification shows that the pH will be lower than the allowable lower limit, then reduce the current cycle supplementary amount of the main salt supplementary channel and postpone the remaining main salt supplementary amount, or simultaneously reduce the action of supplementary channels with greater acidity effects; after adjustment, recalculate the verification predicted concentration of each controlled component until the predicted concentration of each controlled component is within the corresponding process setting range, or reaches the boundary of the executable supplementary range in the current control cycle.

[0062] When the boundary of the executable replenishment range within the current control cycle is reached, and the verification result still shows that the predicted concentration of any controlled component exceeds the corresponding process setting range, the replenishment action within the current control cycle will no longer be increased or expanded. Instead, the executable replenishment amount within the current control cycle will be used as the restricted target replenishment amount, generating a restricted replenishment control instruction, along with abnormal alarm information and manual confirmation information. The restricted replenishment control instruction is used to ensure that the replenishment channel performs the currently achievable replenishment action within the executable replenishment range. The abnormal alarm information is used to indicate that the corresponding controlled component is at risk of falling below the lower allowable limit, exceeding the upper allowable limit, or having accompanying effects that lead to exceeding the limit. The manual confirmation information is used to prompt the operator to verify the tank liquid detection value, replenishment channel status, replenishment liquid balance, or process setting range. Simultaneously, the unexecuted replenishment amount within the current control cycle and the corresponding controlled component identifier are written into the replenishment record of subsequent control cycles, allowing subsequent control cycles to continue participating in replenishment amount allocation and verification adjustments after re-acquiring tank liquid monitoring data and replenishment execution data.

[0063] Specifically, when obtaining retesting data for the plating bath after the completion of a future production batch, the data can be collected after the electroplating and barrel plating baskets have been removed and the preset mixing and stabilization time has elapsed. The preset mixing and stabilization time can be determined based on the plating bath circulation flow rate and the effective volume of the electroplating tank, for example, the time required for one to two cycles of the plating bath. The plating bath retesting data includes the concentration values ​​of each controlled component after the completion of the batch. To determine the actual concentration change, the current concentration before the start of the production batch is used as the pre-batch concentration, and the retested concentration value in the plating bath retesting data is used as the post-batch concentration. The post-batch concentration is compared with the pre-batch concentration to obtain the actual concentration change of each controlled component. For example, if the current concentration of a certain main metal ion before the start of the batch is 50 g / L, and the retested concentration after the batch is 48.6 g / L, then the actual concentration change of this main metal ion is a decrease of 1.4 g / L.

[0064] When determining the predicted concentration change based on the production load data, electrochemical consumption, workpiece carry-out loss, and replenishment execution data corresponding to the production batch, the following steps are taken: First, the actual electroplating current, actual electroplating time, total surface area of ​​the workpiece to be plated, and barrel plating basket operation data for the batch are determined based on the production load data. Then, the electrochemical consumption and workpiece carry-out loss obtained in the previous steps are read and converted into concentration change units consistent with the corresponding controlled components. Subsequently, based on the replenishment execution data of each replenishment channel within the batch, the replenishment increase for each controlled component is determined. For each controlled component, the replenishment increase is considered a positive change, while the electrochemical consumption and workpiece carry-out loss are considered negative changes, and the sum is used to obtain the predicted concentration change of the controlled component. For example, if the predicted electrochemical consumption of a certain main metal ion decreases by 1.0 g / L, the workpiece carry-out loss decreases by 0.3 g / L, and the replenishment execution data within the batch increases by 0.2 g / L, then the predicted concentration change of the main metal ion is a decrease of 1.1 g / L.

[0065] When the prediction deviation is obtained, the actual concentration change is compared with the predicted concentration change, and the difference between the two is taken as the prediction deviation. If the actual concentration change of the main metal ion is a decrease of 1.4 g / L, and the predicted concentration change is a decrease of 1.1 g / L, then the prediction deviation is an additional decrease of 0.3 g / L, indicating that the current preset composition change relationship of the plating solution underestimates the consumption or carry-out loss of the main metal ion in this batch. The preset deviation range can be determined based on the detection accuracy, bath mixing fluctuations, and process allowable fluctuations. For example, it can be taken as 5% to 10% of the width of the process setting range for the controlled component, or it can be determined based on the average fluctuation range of the prediction deviation in several consecutive stable batches. Updates are only performed when the prediction deviation exceeds the preset deviation range to avoid frequent parameter changes due to noise from a single detection.

[0066] When updating the preset composition variation relationship of the plating solution based on the predicted deviation, the controlled component corresponding to the predicted deviation is first determined, and then the deviation contribution of different candidate relationship terms to the predicted deviation is calculated separately. Candidate relationship terms include electrochemical consumption conversion relationship, surface wetting relationship, structural entrainment parameters, carry-out correction parameters, and natural variation relationship. Specifically, for the electrochemical consumption conversion relationship, the candidate contribution of electrochemical consumption is calculated based on the difference between the actual electroplating current and actual electroplating time of the production batch and the current-time integral used in the prediction; for the surface wetting relationship, the candidate contribution of surface wetting is calculated based on the difference between the total surface area of ​​the workpiece to be plated and the total surface area of ​​the workpiece or the calibrated surface area range used in the prediction; for structural entrainment parameters and carry-out correction parameters, the candidate contribution of carry-out loss is calculated based on the difference between the barrel plating basket model, barrel plating basket speed, cumulative rotations, or draining time and the barrel plating basket operating data or calibration conditions used in the prediction; for the natural variation relationship, the candidate contribution of natural variation is calculated based on the difference between the bath temperature, pH, and operating time during batch operation and the temperature, pH, and operating time used in the prediction.

[0067] When calculating the deviation contribution, the deviation between the actual operating parameters corresponding to each candidate relation term and the predicted or calibrated parameters is multiplied by the unit influence coefficient of the change in the concentration of the controlled component for that candidate relation term to obtain the deviation contribution of the corresponding candidate relation term. For example, if the predicted deviation of the main metal ion is an additional decrease of 0.3 g / L, and the actual current-time integral of the batch is higher than the current-time integral used in the prediction, then the candidate contribution of electrochemical consumption is calculated based on the difference between the two and the electrochemical consumption conversion value; if the total surface area of ​​the workpiece to be plated in the batch is higher than the predicted value, or the cumulative number of rotations of the barrel plating basket is higher than the predicted value, then the candidate contribution of surface wetting and the candidate contribution of carry-out correction are calculated respectively.

[0068] The deviation contributions of each candidate relation are compared, and the update target is determined based on the comparison results. When the difference between the largest and second-largest deviation contributions is greater than 20% of the largest deviation contribution, the candidate relation corresponding to the largest deviation contribution is determined as the update target. When the difference between the largest and second-largest deviation contributions is not greater than 20% of the largest deviation contribution, it is determined that the contributions of multiple candidate relation items are close. In this case, a large update is not performed on a single relation item. Instead, the parameter update magnitude is reduced, or a calibration review prompt is generated to avoid attributing the same prediction deviation error to a single relation item.

[0069] The update range is determined based on the prediction deviation and the preset update ratio. Specifically, the deviation correction ratio is first determined based on the proportion of the prediction deviation to the predicted concentration change. Then, the deviation correction ratio is multiplied by the preset update ratio to obtain the parameter correction ratio. The preset update ratio can be between 20% and 50% to avoid over-correction caused by single batch data. At the same time, the single parameter correction ratio should not exceed 5% to 10% of the original parameter value. For example, if the predicted carry-out loss in a certain production batch is 10% lower than the actual carry-out loss, and the preset update ratio is 30%, then the correction ratio for the surface wetting coefficient or carry-out correction parameter in this instance is 10% × 30% = 3%. If the calculated correction ratio exceeds the single allowable limit, then the update is performed according to the single allowable limit.

[0070] In another optional implementation, to further avoid erroneous parameter updates caused by sporadic detection errors or single-batch anomalies, the preset plating solution component change relationship is only updated when the predicted deviation of the same controlled component exceeds the preset deviation range in two or three consecutive production batches, and the deviation directions are consistent. If only a single batch shows a predicted deviation exceeding the limit, a calibration verification prompt is generated, and the corresponding parameters are not updated temporarily. The updated preset plating solution component change relationship is used for generating plating solution chemical change process data, concentration change prediction, and replenishment control command generation in subsequent control cycles.

[0071] Example 1: Supplement Calculation Example for a Single Control Cycle To illustrate the specific execution process of the method within a control cycle, the following description uses a nickel plating bath for electronic connector terminals as an example. The controlled components of this plating bath include nickel sulfate and a brightener. The process setting range for nickel sulfate is 275 g / L to 285 g / L, with a target concentration of 280 g / L; the process setting range for the brightener is 4.5 mL / L to 5.5 mL / L, with a target concentration of 5.0 mL / L. The current control cycle is 3 minutes, and the effective volume of the plating bath is 1000 L.

[0072] During the current control cycle, the online monitoring data for the plating bath is as follows: nickel sulfate concentration is 278.8 g / L, brightener concentration is 4.72 mL / L, bath temperature is 55℃, and pH is 4.5. The replenishment execution data recorded in the previous control cycle was read, showing that 2.0 L of main salt replenishment solution has been added to the main salt replenishment channel, and 120 mL of brightener replenishment solution has been added to the brightener replenishment channel. According to the preset composition change relationship of the plating bath, each 1 L of main salt replenishment solution added increases the nickel sulfate concentration by 0.30 g / L in the current effective bath volume, and each 1 mL of brightener replenishment solution added increases the brightener concentration by 0.002 mL / L in the current effective bath volume. Based on the replenishment completion time, the current monitoring time, and the mixing stabilization time, it is determined that 70% of the impact of the main salt replenishment in the previous control cycle is reflected in the current monitoring concentration, and 60% of the impact of the brightener replenishment is reflected in the current monitoring concentration. Therefore, the remaining amount of nickel sulfate added through the main salt replenishment channel is 2.0 × 0.30 × (1 - 70%) = 0.18 g / L; the remaining amount of brightener added through the brightener replenishment channel is 120 × 0.002 × (1 - 60%) = 0.096 mL / L.

[0073] Based on the preset compositional variation relationship of the plating solution, under the current conditions of 55℃ and pH 4.5, the natural variation value of the brightener per unit time is a decrease of 0.005 mL / L per minute. The detection lag from sampling to the current control calculation time at the online detection terminal is 1 minute, therefore the change in brightener during the detection lag process is a decrease of 0.005 mL / L. The natural variation of nickel sulfate within this detection lag is negligible relative to the control accuracy and is taken as 0. Therefore, the current concentration determination results are: the current concentration determination result of nickel sulfate is 278.8 + 0.18 = 278.98 g / L; the current concentration determination result of brightener is 4.72 + 0.096 - 0.005 = 4.811 mL / L.

[0074] Subsequently, production load data was read. The total surface area of ​​the workpieces to be plated in the future production batch is 15 m², the planned electroplating current is 100 A, the planned electroplating duration is 30 min, and the cumulative number of rotations of the barrel plating basket is 20. According to the electrochemical consumption conversion relationship, the unit current-time consumption value for nickel sulfate is 0.02 g per A·min. Therefore, the electrochemical consumption of nickel sulfate in the future production batch is 100 × 30 × 0.02 = 60 g, which translates to a concentration decrease of 60 g ÷ 1000 L = 0.06 g / L. Brightener is not calculated based on electrochemical deposition consumption; its natural consumption will be calculated based on the natural change value per unit time in subsequent predictions.

[0075] Based on the preset surface wetting relationship, the liquid carrying coefficient per unit surface area is 0.08 L / m², so the liquid carrying amount on the workpiece surface is 15 × 0.08 = 1.2 L; the carrying amount of the barrel plating basket structure is 0.5 L; the dynamic enhancement coefficient per revolution is 0.005 / revolution, and the effective cumulative number of revolutions is 20 revolutions, so the liquid carrying amount out of the workpiece is (1.2 + 0.5) × (1 + 0.005 × 20) = 1.87 L. Based on the current concentration, the loss of nickel sulfate carried out by the workpiece is calculated as 1.87 × 278.98 g = 521.69 g, which translates to a concentration decrease of 521.69 g ÷ 1000 L = 0.522 g / L; the loss of brightener carried out by the workpiece is calculated as 1.87 × 4.811 mL = 9.00 mL, which translates to a concentration decrease of 9.00 mL / 1000 L = 0.009 mL / L.

[0076] Assuming the future control time domain is one future production batch, the predicted concentration of nickel sulfate at the end of this production batch is 278.98 - 0.06 - 0.522 = 278.398 g / L. This predicted concentration remains within the process setting range of 275 g / L to 285 g / L and is not lower than the trigger condition corresponding to the preset warning margin. Therefore, no new demand for nickel sulfate will be generated in the current control cycle. The predicted natural variation of brightener within this production batch is 0.005 × 30 = 0.15 mL / L. Therefore, the predicted concentration of brightener at the end of this production batch is 4.811 - 0.009 - 0.15 = 4.652 mL / L. If the preset warning margin is 20% of the process setting range width, i.e. 0.2 mL / L, then the margin of brightener from the allowable lower limit of 4.5 mL / L is 0.152 mL / L, which is less than the preset warning margin, thus triggering the pre-addition judgment; the difference between the target concentration of 5.0 mL / L and the predicted concentration of 4.652 mL / L is used as the predicted deviation, and the predicted deviation of brightener is 0.348 mL / L.

[0077] The required replenishment amount is determined based on the predicted deviation of the brightener. Since each 1 mL of brightener replenishment solution increases the brightener concentration by 0.002 mL / L in the current effective tank volume, the required brightener replenishment amount is 0.348 ÷ 0.002 = 174 mL. Based on the correspondence between the controlled component and the replenishment channel, this required replenishment amount is allocated to the brightener replenishment channel, resulting in an initial replenishment amount of 174 mL for the brightener replenishment channel.

[0078] Further verification was conducted based on the accompanying effects. The pre-set compositional variation relationship of the plating solution showed that the accompanying effects of the brightener replenishment solution on the wetting agent and pH did not cause the corresponding controlled components to exceed the process setting range at a replenishment volume of 174 mL. Simultaneously, the executable replenishment range for the brightener replenishment channel in the current control cycle was 50 mL to 250 mL, and both the replenishment interval and the allowable replenishment rate met the execution conditions. Therefore, 174 mL was determined as the target replenishment volume for the brightener replenishment channel within the current control cycle, and the replenishment sequence was set to perform one replenishment within the current control cycle. This generated a channel replenishment control instruction, which included the brightener replenishment channel identifier, brightener replenishment solution type, target replenishment volume of 174 mL, and replenishment execution sequence.

[0079] After replenishment is completed, record the replenishment execution data for that replenishment channel. If the metering pump's calibrated flow rate is 58 mL / min, then the running time corresponding to a replenishment volume of 174 mL is 174 ÷ 58 = 3 min. When the metering pump feedback signal is normal, and the actual replenishment volume calculated based on the running time is 174 mL, and the deviation between the actual replenishment volume and the target replenishment volume is within the allowable execution error range, record the execution status as replenishment complete. This replenishment execution data serves as input data for the next control cycle to correct for the impact of remaining replenishment and predict concentration changes.

[0080] Example 2: To verify the actual control effect of the intelligent monitoring and automatic replenishment method for barrel plating bath of this application, a comparative verification was conducted on a test platform equipped with barrel plating production conditions. The verification object was a barrel plating production line for nickel plating of electronic connector terminals. The key components to be controlled in the bath included nickel sulfate and brightener, wherein the target concentration of nickel sulfate was 280 g / L and the target concentration of brightener was 5 mL / L.

[0081] In this embodiment, the intelligent monitoring and automatic replenishment method for barrel plating baths is used for bath control. Specifically, bath monitoring data is acquired using an ion-selective electrode for detecting main metal ions and an online ultraviolet-visible spectroscopy analysis module. Based on the bath monitoring data of the current control cycle, production load data, and replenishment execution data recorded in the previous control cycle, the current concentration is determined. Furthermore, based on the production load data corresponding to future production batches, the electrochemical consumption and workpiece carry-out loss are determined, the concentration change trend of each controlled component in the future control time domain is predicted, and a channel replenishment control command is generated to control the corresponding replenishment channel to perform chemical replenishment.

[0082] In the comparative example, traditional bath maintenance methods were used for control. For nickel sulfate, the consumption was estimated using an ampero-hour meter, and replenishment was performed every hour using a timed control method. For brightener, since online quantitative monitoring was not performed, the estimated amount was replenished every 4 hours using manual experience.

[0083] During the validation process, a dynamic production process was simulated for 24 consecutive hours, with multiple batches of workpieces randomly introduced. The total surface area of ​​each batch of workpieces varied between 0.5 m² and 2.0 m² to simulate the production load fluctuations during barrel plating. Throughout the validation process, samples of the plating bath were extracted every 15 minutes, and the concentrations of nickel sulfate and brightener were measured using laboratory analytical equipment. The results were used as reference data for comparing the two control methods.

[0084] The results of comparing the stability of the concentration of the controlled component in the bath under different control methods are as follows: For nickel sulfate, the target concentration is 280.0 g / L. When controlled using the embodiment of this application, the 24-hour average concentration is 280.2 g / L, the standard deviation is 0.8 g / L, and the maximum deviation is ±2.1 g / L. When controlled using the comparative embodiment, the 24-hour average concentration is 278.5 g / L, the standard deviation is 4.5 g / L, and the maximum deviation is ±12.5 g / L. Therefore, under the same target concentration conditions, the embodiment of this application can make the nickel sulfate concentration closer to the target concentration and reduce the concentration fluctuation.

[0085] For the brightener, the target concentration is 5.0 mL / L. When controlled using the embodiments of this application, the 24-hour average concentration is 5.01 mL / L, the standard deviation is 0.09 mL / L, and the maximum deviation is ±0.25 mL / L. When controlled using the comparative example, the 24-hour average concentration is 4.65 mL / L, the standard deviation is 0.82 mL / L, and the maximum deviation is ±2.5 mL / L. Therefore, the embodiments of this application can reduce the fluctuation of the brightener concentration during continuous production and maintain it near the target concentration.

[0086] In summary, compared with the comparative example, the embodiments of this application exhibit smaller concentration standard deviations and maximum deviations for both nickel sulfate and brightener, indicating that the present application can improve the stability of concentration control of controlled components in the barrel plating bath by combining bath monitoring data, production load data, and replenishment execution data.

[0087] The comparison results show that when the control is performed using the embodiments of this application, the average concentration of nickel sulfate over 24 hours is 280.2 g / L, the standard deviation is 0.8 g / L, and the maximum deviation is ±2.1 g / L. When the control is performed using the comparative example, the average concentration of nickel sulfate over 24 hours is 278.5 g / L, the standard deviation is 4.5 g / L, and the maximum deviation is ±12.5 g / L. Therefore, the embodiments of this application can reduce the fluctuation of the main metal ion concentration under varying production load conditions.

[0088] For brighteners, when controlled using the embodiments of this application, the average concentration of the brightener over 24 hours was 5.01 mL / L, the standard deviation was 0.09 mL / L, and the maximum deviation was ±0.25 mL / L. When controlled using the comparative embodiment, the average concentration of the brightener over 24 hours was 4.65 mL / L, the standard deviation was 0.82 mL / L, and the maximum deviation was ±2.5 mL / L. Therefore, the embodiments of this application can perform online monitoring and replenishment control of organic additives such as brighteners, thereby reducing their concentration fluctuations.

[0089] Further analysis of the concentration change curves reveals that, during continuous production, the nickel sulfate and brightener concentrations in the embodiments of this application fluctuate slightly around their respective target concentrations. In contrast, the concentration curves in the comparative examples exhibit more pronounced periodic fluctuations, particularly after changes in production batch load, which can easily lead to delayed replenishment or concentration deviations. These results demonstrate that this application, through current concentration determination, future load disturbance prediction, and channel replenishment control, can improve the stability of the controlled component concentration in the barrel plating bath.

[0090] See Figure 3-4 As shown, the nickel sulfate concentration and brightener concentration are referenced to their respective target concentrations. Figure 3 It can be seen that during the continuous 24-hour dynamic production process, the nickel sulfate concentration corresponding to the embodiment of this application fluctuated slightly around the target concentration of 280.0 g / L, while the nickel sulfate concentration curve of the comparative example showed more obvious stage-wise rises and falls; from Figure 4 It can be seen that the brightener concentration in the embodiments of this application fluctuates slightly around the target concentration of 5.0 mL / L, while the brightener concentration curve in the comparative example deviates significantly. Combining the concentration standard deviation and the maximum deviation, it can be concluded that the embodiments of this application can predict and control the concentration of the controlled components in the bath solution based on bath monitoring data, production load data, and replenishment execution data, even when the total surface area of ​​different batches of workpieces varies, thereby reducing the concentration fluctuation of the controlled components in the bath solution.

[0091] In another preferred embodiment based on the above embodiments, see [reference] Figure 5 As shown, this embodiment provides an intelligent monitoring and automatic replenishment system for barrel plating bath solutions, including: The data acquisition module is used to acquire the bath liquid monitoring data and production load data of the current control cycle, read the replenishment execution data recorded in the previous control cycle, and generate the chemical change process data of the plating solution according to the preset plating solution component change relationship. The concentration determination module is used to correct the residual replenishment effect and the detection time lag process change for the concentration of each component to be controlled corresponding to the bath solution monitoring data based on the bath solution monitoring data, replenishment execution data and chemical change process data of the plating solution, so as to obtain the current concentration determination result. The concentration prediction module is used to determine the electrochemical consumption and workpiece carry-out loss corresponding to the future production batch based on the production load data. The electrochemical consumption and workpiece carry-out loss are used as load disturbance inputs for concentration change prediction. Combined with the current concentration determination results, the module predicts the concentration change trend of each controlled component in the future control time domain. The replenishment instruction generation module is used to determine the target replenishment amount and replenishment sequence of each replenishment channel in the current control cycle based on the deviation between the concentration change trend and the process setting range of each controlled component, and in combination with the executable replenishment range of each replenishment channel, and generate channel replenishment control instructions. The replenishment execution module is used to control each replenishment channel to replenish the corresponding chemicals according to the channel replenishment control command, and to record the replenishment execution data after each replenishment channel has completed replenishment.

[0092] It is understandable that the above-mentioned intelligent monitoring and automatic replenishment system and method for barrel plating bath has the same beneficial effects, and will not be elaborated further here.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope defined by the present invention.

Claims

1. A method for intelligent monitoring and automatic replenishment of barrel plating bath solution, characterized in that, include: Acquire the bath solution monitoring data and production load data for the current control cycle, read the replenishment execution data recorded in the previous control cycle, and generate the chemical change process data of the plating solution based on the preset composition change relationship of the plating solution; Based on the bath solution monitoring data, the replenishment execution data, and the plating solution chemical change process data, the concentrations of each component to be controlled corresponding to the bath solution monitoring data are corrected for the influence of residual replenishment and the change in detection time lag process to obtain the current concentration determination result. Based on the production load data, the electrochemical consumption and workpiece carry-out loss corresponding to the future production batch are determined. The electrochemical consumption and workpiece carry-out loss are used as load disturbance inputs for concentration change prediction. Combined with the current concentration determination results, the concentration change trend of each controlled component in the future control time domain is predicted. Based on the deviation between the concentration change trend and the process setting range of each controlled component, and in combination with the executable replenishment range of each replenishment channel, the target replenishment amount and replenishment sequence of each replenishment channel in the current control cycle are determined, and channel replenishment control instructions are generated. According to the channel replenishment control command, each replenishment channel is controlled to replenish the corresponding chemical, and the replenishment execution data after each replenishment channel is completed is recorded.

2. The intelligent monitoring and automatic replenishment method for barrel plating bath solution according to claim 1, characterized in that, When generating data on the chemical change process of the plating solution based on the preset compositional change relationship, the following are included: Based on the supplementation execution data, determine the supplementation impact of each supplementation channel on each controlled component; Based on the bath solution monitoring data of the current control cycle and the preset composition change relationship of the plating solution, determine the natural change amount of each component to be controlled within the current control cycle; The added influence and the natural variation are grouped according to the corresponding controlled components to obtain the chemical change process data of the plating solution.

3. The intelligent monitoring and automatic replenishment method for the barrel plating bath solution according to claim 2, characterized in that, When correcting for the effects of residual replenishment and changes in detection time lag in the concentrations of each controlled component corresponding to the bath solution monitoring data, the following applies: Extract the monitoring concentration values ​​corresponding to each component to be controlled from the tank liquid monitoring data, and use the monitoring concentration values ​​as the concentration benchmark values ​​for the current control cycle; Extract the residual replenishment influence and the change in detection time lag process of each component to be controlled from the chemical change process data of the plating solution; Based on the remaining supplementary influence and the change in the detection time lag process, the concentration benchmark value is corrected to obtain the current concentration determination result of each component to be controlled.

4. The intelligent monitoring and automatic replenishment method for the barrel plating bath according to claim 3, characterized in that, When determining the electrochemical consumption and workpiece carry-out loss corresponding to future production batches based on the aforementioned production load data, the following are included: Read the planned electroplating data for future production batches, the total surface area of ​​the workpieces to be plated, and the operating data of the barrel plating basket from the production load data; Based on the planned electroplating data and the electrochemical consumption conversion relationship for each component to be controlled, the electrochemical consumption for future production batches is determined. Based on the total surface area of ​​the workpiece to be plated, the operating data of the barrel plating basket, and the current concentration determination result, the loss amount of each controlled component carried out with the workpiece is determined, and the loss amount of each controlled component carried out with the workpiece is taken as the workpiece carry-out loss amount.

5. The intelligent monitoring and automatic replenishment method for barrel plating bath solution according to claim 4, characterized in that, When determining the loss of each controlled component carried away by the workpiece based on the total surface area of ​​the workpiece to be plated, the operating data of the barrel plating basket, and the current concentration determination result, the following are included: Based on the total surface area of ​​the workpiece to be plated and the preset surface wetting relationship, determine the amount of liquid on the workpiece surface corresponding to the surface of the workpiece to be plated; The amount of structural entrainment is determined based on the preset structural entrainment parameters corresponding to the barrel plating basket; Based on the operating data of the barrel plating basket, the amount of liquid carried on the surface of the workpiece and the amount of liquid entrained in the structure are corrected to obtain the amount of liquid carried out of the workpiece for future production batches. Based on the amount of liquid carried out by the workpiece and the current concentration, the loss of each controlled component carried out by the workpiece is determined.

6. The intelligent monitoring and automatic replenishment method for barrel plating bath according to claim 5, characterized in that, When predicting the concentration trends of each controlled component within the future control time domain, the following should be considered: Based on the current concentration determination result, the electrochemical consumption, and the workpiece carry-out loss, the predicted concentration of each component to be controlled in the future control time domain is determined; Based on the difference between the predicted concentration and the process setting range of each component to be controlled, the concentration change trend of each component to be controlled in the future control time domain is generated.

7. The intelligent monitoring and automatic replenishment method for barrel plating bath solution according to claim 6, characterized in that, When determining the target replenishment amount and replenishment timing for each replenishment channel within the current control cycle, the following should be included: Based on the concentration change trend, determine the predicted deviation of each controlled component relative to the corresponding process setting range; Based on the predicted deviation, determine the required replenishment amount for each controlled component; Based on the correspondence between each controlled component and each replenishment channel, the required replenishment amount is allocated to the corresponding replenishment channel; Based on the executable replenishment range of each replenishment channel, the required replenishment amount allocated to each replenishment channel is adjusted to obtain the target replenishment amount and replenishment timing of each replenishment channel in the current control cycle, and the channel replenishment control command is generated.

8. The intelligent monitoring and automatic replenishment method for barrel plating bath according to claim 7, characterized in that, When allocating the required replenishment amount to the corresponding replenishment channel according to the correspondence between each controlled component and each replenishment channel, the following steps are included: Determine the main supplementation effect of each supplementation channel on the target controlled component, as well as the accompanying effects on non-target controlled components; Based on the main replenishment function, the required replenishment amount of each controlled component is allocated to the corresponding replenishment channel to obtain the initial replenishment amount of each replenishment channel; Based on the accompanying effects, the predicted concentrations of each controlled component after the initial supplementation were verified. When the verification results show that the predicted concentration of any controlled component exceeds the corresponding process setting range, the initial replenishment amount of the replenishment channel related to the controlled component is adjusted to obtain the target replenishment amount of each replenishment channel in the current control cycle.

9. The intelligent monitoring and automatic replenishment method for barrel plating bath according to claim 8, characterized in that, After recording the supplementation execution data after each supplementation channel is completed, it also includes: After the production batch is completed, obtain the bath solution retest data, and determine the actual concentration change of each controlled component based on the bath solution retest data; Based on the production load data, electrochemical consumption, workpiece carry-out loss, and replenishment execution data corresponding to the production batch, the predicted concentration change of each controlled component is determined. The actual concentration change is compared with the predicted concentration change to obtain the prediction deviation. When the predicted deviation exceeds the preset deviation range, the preset plating solution composition change relationship is updated based on the predicted deviation.

10. A smart monitoring and automatic replenishment system for barrel plating bath solution, used to implement the smart monitoring and automatic replenishment method for barrel plating bath solution as described in any one of claims 1-9, characterized in that, include: The data acquisition module is used to acquire the bath liquid monitoring data and production load data of the current control cycle, read the replenishment execution data recorded in the previous control cycle, and generate the chemical change process data of the plating solution according to the preset plating solution component change relationship. The concentration determination module is used to correct the residual replenishment effect and the detection time lag process change for the concentration of each component to be controlled corresponding to the bath liquid monitoring data based on the bath liquid monitoring data, the replenishment execution data and the chemical change process data of the plating solution, so as to obtain the current concentration determination result. The concentration prediction module is used to determine the electrochemical consumption and workpiece carry-out loss corresponding to the future production batch based on the production load data. The electrochemical consumption and workpiece carry-out loss are used as load disturbance inputs for concentration change prediction. Combined with the current concentration determination results, the module predicts the concentration change trend of each controlled component in the future control time domain. The replenishment instruction generation module is used to determine the target replenishment amount and replenishment sequence of each replenishment channel in the current control cycle based on the deviation between the concentration change trend and the process setting range of each controlled component, and in combination with the executable replenishment range of each replenishment channel, and generate channel replenishment control instructions. The replenishment execution module is used to control each replenishment channel to replenish the corresponding chemical according to the channel replenishment control command, and to record the replenishment execution data after each replenishment channel has completed replenishment.

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