Cyanide-free electroplating solution component on-line analysis and replenishment control system for semiconductor packaging

Abstract

This invention relates to the field of electroplating solution replenishment control technology, and discloses an online analysis and replenishment control system for cyanide-free electroplating solutions for semiconductor packaging. The system includes: a parameter acquisition and concentration extraction module, a kinetic decay assessment module, a Faraday consumption calculation module, a replenishment acceleration rate prediction model construction module, and a control command conversion module. By acquiring operating environment parameters and macroscopic concentration data, the system calculates the spontaneous kinetic degradation rate, quantifies the latent losses in the non-energized state, calculates the electrochemical Faraday consumption rate, constructs a replenishment acceleration rate prediction model, calculates the replenishment acceleration rate control quantity, and converts it into the control command pulse frequency to drive the metering pump assembly, injecting replenishment solution into the circulation pipeline. This invention actively compensates for the non-electrochemical losses of the complexing agent, avoiding the metal ion disproportionation autocatalysis caused by relying solely on concentration feedback lag, thereby improving the long-term stability and process yield of cyanide-free electroplating solutions in high-precision semiconductor packaging.

Description

Technical Field

[0001] This invention relates to the field of electroplating solution replenishment rate control technology, specifically to an online analysis and replenishment control system for cyanide-free electroplating solutions for semiconductor packaging. Background Technology

[0002] With the continuous evolution of semiconductor manufacturing technology, high-precision advanced packaging technologies such as Through Silicon Vias (TSV) and Micro-bumps place higher demands on the precise control of wafer-level electroplating processes. Among these, cyanide-free electroplating systems, such as gold sulfite, have been widely deployed in electroplating lines of advanced semiconductor packaging plants due to their environmental friendliness and excellent deposition characteristics. In cyanide-free electroplating processes, the long-term stability of the concentrations of various components in the plating solution (such as main salt metal ions and complexing agents) determines the uniformity and yield of the plating layer. Therefore, constructing a precise electroplating solution replenishment control system is a crucial step in ensuring the reliable operation of the production line.

[0003] Traditional methods for controlling the replenishment of components in cyanide-free electroplating solutions typically rely on simple ampero-hour meters for feedforward estimation or on hysteresis feedback replenishment combined with a single spectral concentration deviation. Specifically, the ampero-hour meter method, based on Faraday's law of electrolysis, calculates the electrochemical consumption of metal ions by accumulating the electricity consumed during the electroplating process, and drives a metering pump to replenish according to a set ratio. The concentration deviation feedback method, on the other hand, relies on basic spectral sensors to monitor the macroscopic concentration. When the system detects that the measured concentration is lower than a set process threshold, it then initiates the corresponding replenishment procedure to compensate for the concentration difference.

[0004] However, the existing technologies have some shortcomings: the feedforward control logic of existing ampero-hour meters can only calculate electrochemical consumption based on the current, ignoring non-electrochemical consumption. For example, in non-electro-current states, cyanide-free systems may experience spontaneous degradation of complexes due to thermodynamic instability, dissolved oxygen oxidation, and pH fluctuations. This means that during equipment shutdown for heat preservation or low-current packaging, the lack of significant current accumulation prevents the ampero-hour meter from issuing feedforward replenishment commands for the implicit spontaneous degradation of complexes. Furthermore, existing passive feedback mechanisms relying on spectral concentration have a time lag problem; replenishment is only triggered when a large amount of free complexing agent is lost, causing the concentration to fall below the lower limit. The lack of feedforward compensation for non-electrochemical consumption, combined with the lag in passive feedback, prevents the system from responding synchronously during the continuous degradation of complexes. This can easily lead to irreversible disproportionation autocatalytic reactions of metal ions within the system, limiting the long-term stability and yield of cyanide-free systems in high-precision semiconductor packaging. Therefore, an online analysis and replenishment control system for cyanide-free electroplating solutions for semiconductor packaging is urgently needed to solve these problems. Summary of the Invention

[0005] To address the problems in related technologies, this invention provides an online analysis and replenishment control system for cyanide-free electroplating solutions used in semiconductor packaging, thereby overcoming the aforementioned technical problems in existing related technologies.

[0006] To solve the aforementioned technical problem, the present invention is achieved through the following technical solution: In a first aspect, embodiments of the present invention provide an online analysis and replenishment control system for cyanide-free electroplating solutions for semiconductor packaging, specifically comprising: a parameter acquisition and concentration extraction module, used to acquire operating environment parameters and simultaneously extract macroscopic concentration data during the electroplating solution circulation process; a kinetic decay assessment module, used to quantify the latent losses in the non-energized state and calculate the spontaneous kinetic degradation rate based on the operating environment parameters and the macroscopic concentration data; a Faraday consumption calculation module, used to calculate the electrochemical Faraday consumption rate caused by cathode deposition and hydrogen evolution side reactions based on the operating environment parameters and the electroplating process state; a replenishment acceleration rate prediction model construction module, used to combine the spontaneous kinetic degradation rate and the electrochemical Faraday consumption rate for feedforward compensation and feedback correction, construct a replenishment acceleration rate prediction model and calculate the replenishment acceleration rate control quantity; and a control command conversion module, used to receive the replenishment acceleration rate control quantity and, in conjunction with the concentration of the replenishment solution stock solution, convert the replenishment acceleration rate control quantity into a control command pulse frequency for driving the metering pump assembly, and inject the replenishment solution into the circulation pipeline.

[0007] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution for semiconductor packaging described in this invention, the specific steps of the parameter acquisition and concentration extraction module include: Multidimensional operating environment parameters are collected during the electroplating solution circulation process using a sensor array. These operating environment parameters include at least temperature, pH value, dissolved oxygen concentration, and electroplating current. The raw spectral signal containing the main salt and complexing agent is acquired and processed to eliminate baseline shift and background interference, and to extract pure spectral feature vectors. By combining the spectral feature vector with the pre-calibrated weighting coefficients and bias constants, the macroscopic concentration data of the main salt and complexing agent at the current moment are extracted; Based on the output timestamp of the spectral data, the environmental and process status parameters of the corresponding time node are matched in the historical data queue to generate a synchronized status parameter vector.

[0008] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution for semiconductor packaging described in this invention, the specific steps of the kinetic decay assessment module in calculating the spontaneous kinetic degradation rate include: Based on the apparent activation energy, pre-exponential factor, and current absolute temperature of the cyanide-free electroplating solution system, a real-time thermodynamic degradation rate constant reflecting the spontaneous decomposition rate of the complexing agent is determined; and the real-time thermodynamic degradation rate constant, the total working volume of the system, and the macroscopic concentration of the complexing agent are correlated and quantified into a thermodynamic degradation rate base. Based on the real-time collected dissolved oxygen concentration and the preset dissolved oxygen oxidation reaction rate constant, a real-time oxidation attenuation factor reflecting the strength of the oxidation reaction is determined; and the real-time oxidation attenuation factor, the total working volume of the system, and the macroscopic concentration of the free complexing agent are correlated and quantified as the increment of the oxidation degradation rate. Based on the deviation of the current pH value from the optimal process stable pH value, the catalytic effect of hydrogen ion concentration change on the hydrolysis reaction is evaluated to determine the real-time hydrolysis acceleration factor; and the hydrolysis rate constant, real-time hydrolysis acceleration factor, total system working volume and macroscopic concentration of free complexing agent are correlated and quantified as the hydrolysis degradation rate increment. An interactive coupling correction term is introduced, and the spontaneous kinetic degradation rate is determined by combining the synergistic contributions of the thermodynamic degradation rate base, the oxidative degradation rate increment, and the hydrolytic degradation rate increment to the total loss of the complexing agent.

[0009] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution for semiconductor packaging described in this invention, the process for determining the apparent activation energy and pre-exponential factor includes: The dynamic change data of complexing agent concentration decay over time at various specific temperatures in the isothermal accelerated aging experiment were obtained, and the specific reaction rate constant at each specific temperature was extracted. A two-dimensional data mapping space based on the reciprocal of absolute temperature and the natural logarithm of the reaction rate constant is constructed, and the characteristic parameters of the fitted line are extracted through linear regression analysis. The apparent activation energy is determined by combining the slope of the fitted line with the ideal gas constant, and the pre-exponential factor is determined by performing an exponential reduction operation based on the ordinate of the fitted line.

[0010] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution for semiconductor packaging described in this invention, the process of determining the preset constants in the oxidative degradation rate increment and the hydrolytic degradation rate increment includes: The dissolved oxygen oxidation reaction rate constant was determined by constructing a positive linear correlation between different absolute dissolved oxygen concentrations and the corresponding oxidative degradation rates, and extracting the slope of the best-fit line. The hydrolysis rate constant is determined by inversely extrapolating the basic hydrolysis rate through the linear relationship between the difference between the optimal process stable pH value and the actual acidification adjusted pH value and the corresponding logarithm of the accelerated degradation rate.

[0011] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution for semiconductor packaging described in this invention, the specific steps of the Faraday consumption calculation module in calculating the electrochemical Faraday consumption rate include: Extract the number of electrons transferred in the reduction reaction of the corresponding target component; The real-time cathode current density is calculated based on the instantaneous electroplating current and the total effective electroplating area, and the true cathode current efficiency is extracted by dynamic addressing according to the mapping table configured in the system. The effective reactive charge flux is evaluated based on a comprehensive assessment of the instantaneous electroplating current and the actual cathode current efficiency. The effective reaction charge flux is projected onto a reaction charge equivalent benchmark established by combining the number of electron transfers and the Faraday constant for quantification and conversion to obtain the electrochemical Faraday consumption rate.

[0012] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution for semiconductor packaging described in this invention, the specific operation steps of the replenishment rate prediction model construction module include: The spontaneous kinetic degradation rate is used as an independent feedforward compensation term, and combined with the electrochemical Faraday consumption rate, the predictive feedforward total consumption rate is comprehensively evaluated. Based on the deviation between the process target concentration and the current macroscopically measured concentration, the closed-loop feedback correction amount is determined by combining the closed-loop proportional feedback gain coefficient and the integral gain coefficient. By combining the predictive feedforward total consumption rate and the closed-loop feedback correction, the acceleration prediction model is constructed to output the acceleration control quantity. In calculating the feedback correction amount, a dynamic limit weakening integral logic is introduced: when the theoretical control command triggers the system's hard boundary saturation limit and the concentration deviation is positive, the cumulative action of the integral term is forcibly truncated.

[0013] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging described in this invention, the process for determining the interactive coupling correction term includes: The system identifies the coupling relationships between three degradation pathways: thermodynamics and oxidation, thermodynamics and hydrolysis, and oxidation and hydrolysis. Based on the relative strength of their respective degradation rates, it determines whether there are interactive enhancement or interactive weakening effects. For each set of interactions, the harmonic average of the two degradation rates in each set is used as the basic characterization of the interaction strength, and combined with the pre-calibrated interaction coupling coefficient, the net contribution of each set of interactions to the total degradation rate is quantified. The quantitative results of the three sets of interactions—thermodynamics and oxidation, thermodynamics and hydrolysis, and oxidation and hydrolysis—are linearly superimposed to form a complete interaction coupling correction term, which is used to reflect the comprehensive impact of multipath coupling on the total loss of the complexing agent.

[0014] As a preferred embodiment of the online analysis and replenishment control system for cyanide-free electroplating solution for semiconductor packaging described in this invention, the specific operation steps of the control command conversion module include: Based on the proportional mapping relationship between the replenishment rate control quantity and the concentration of the replenishment solution stock solution, the molar consumption rate of the target component is converted into the real-time volume replenishment flow rate required by the system. The volumetric replenishment flow rate is scaled using the volumetric pulse constant of the metering pump to generate a theoretical control pulse frequency; Based on the set maximum safe operating frequency, a hard boundary saturation limiting constraint is applied to the theoretical control pulse frequency, and a safe command pulse frequency is output. The underlying modulation module generates a hardware square wave signal based on the frequency of the safety command pulse, which drives the metering pump to inject replenishment liquid into the circulation pipeline.

[0015] Secondly, embodiments of the present invention provide an electroplating device for advanced semiconductor packaging, specifically including: a main electroplating tank, a circulation pipeline, a bypass microfluidic detection cell, a multimodal sensor array, a stepper metering pump, and an online analysis and replenishment control system for the composition of a cyanide-free electroplating solution for semiconductor packaging. The online analysis and replenishment control system for the composition of a cyanide-free electroplating solution for semiconductor packaging is electrically connected to the multimodal sensor array and the stepper metering pump, respectively. The multimodal sensor array collects operating environment parameters and macroscopic concentration data in real time, and calculates and outputs command pulse frequencies to drive the stepper metering pump to precisely inject replenishment solution into the circulation pipeline.

[0016] The present invention has the following beneficial effects: This invention quantifies the spontaneous kinetic degradation rate of the cyanide-free electroplating system caused by thermodynamic instability, dissolved oxygen oxidation, and acidification shift by real-time acquisition of environmental parameters such as temperature, dissolved oxygen concentration, and pH value. This rate is then introduced as an independent feedforward compensation term into the acceleration rate prediction model to calculate the acceleration rate control quantity and obtain the required volumetric flow rate for the system. This breaks through the limitation of traditional ampere-hour meters that rely solely on the current for evaluation. The system can actively compensate for the non-electrochemical loss of the complexing agent even during equipment shutdown and heat preservation or low-current packaging stages, thereby avoiding metal ion disproportionation autocatalysis caused by relying solely on concentration feedback lag. This improves the long-term stability and process yield of the cyanide-free electroplating solution in high-precision semiconductor packaging. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, the drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This invention provides a schematic diagram of a module for an online analysis and replenishment control system for cyanide-free electroplating solutions used in semiconductor packaging.

[0019] Figure 2 The flowchart illustrates the online analysis and replenishment control method for cyanide-free electroplating solution composition for semiconductor packaging provided by this invention.

[0020] Figure 3 This is a schematic diagram of the electroplating equipment structure for advanced semiconductor packaging provided by the present invention. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example 1

[0022] Traditional methods for controlling the replenishment of cyanide-free electroplating solutions typically rely on simple ampero-hour meters and spectral concentration deviations for hysteretic feedback replenishment. This ignores the spontaneous degradation of complexes caused by thermodynamic instability, dissolved oxygen oxidation, and pH fluctuations in cyanide-free systems under non-energized conditions. During equipment shutdown for heat preservation or low-current packaging, the actual concentration of the complexing agent can easily decrease, and the system may fail to respond promptly, leading to metal ion disproportionation and autocatalysis within the system. This limits the long-term stability and yield of cyanide-free systems in high-precision semiconductor packaging.

[0023] To solve the above technical problems, such as Figure 1As shown, Embodiment 1 of the present invention provides an online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging, specifically including: a parameter acquisition and concentration extraction module, a kinetic decay assessment module, a Faraday consumption calculation module, a replenishment acceleration rate prediction model construction module, and a control command conversion module. The parameter acquisition and concentration extraction module is used to acquire operating environment parameters and simultaneously extract macroscopic concentration data during the electroplating solution circulation process; the kinetic decay assessment module, based on the operating environment parameters and macroscopic concentration data, quantifies the implicit losses under non-energized conditions, calculates the spontaneous kinetic degradation rate, and quantifies the spontaneous kinetic degradation rate of the cyanide-free electroplating system caused by thermodynamic instability, dissolved oxygen oxidation, and acidification shift; the Faraday consumption calculation module, based on the operating environment parameters and the electroplating process state, calculates the electrochemical Faraday consumption rate caused by cathode deposition and hydrogen evolution side reactions; the replenishment acceleration rate prediction module... The model building module is used to combine the spontaneous kinetic degradation rate and the electrochemical Faraday consumption rate for feedforward compensation and feedback correction, construct a replenishment rate prediction model and calculate the replenishment rate control quantity, so that the system can actively compensate for the non-electrochemical loss of the complexing agent, avoid the metal ion disproportionation autocatalysis caused by simply relying on concentration feedback lag, and improve the long-term stability and process yield of cyanide-free electroplating solution in high-precision semiconductor packaging; the control command conversion module is used to receive the replenishment rate control quantity, and combine it with the concentration of the replenishment liquid stock solution, convert it into control command pulses to drive the metering pump component, and inject the replenishment liquid into the circulation pipeline.

[0024] Specific embodiment 1 is as follows: In the wafer-level electroplating workshop of a large semiconductor advanced packaging plant, a gold sulfite cyanide-free electroplating production line is deployed at its TSV (Through Silicon Via) and Micro-bump (micro-bump) workstations. The total working volume of the system is 40L. Multidimensional parameters are collected using an online analyzer that integrates Raman spectroscopy and microelectrode array, and a high-precision stepper metering pump is connected to provide the data basis for embodiment 1 of the present invention.

[0025] Furthermore, to better illustrate the technical solution of Embodiment 1 of the present invention, such as... Figure 2 As shown, this paper describes in detail the online analysis and replenishment control system for cyanide-free electroplating solutions, based on an online analysis and replenishment control method for cyanide-free electroplating solutions used in semiconductor packaging. The specific details include the following: S1. During the electroplating solution circulation process, collect operating environment parameters and macroscopic concentration data. Specifically: The sensor array continuously collects environmental parameters of the current electroplating tank at a preset cycle, and simultaneously extracts macroscopic concentration data, including the macroscopic concentration of the main salt and the macroscopic concentration of the complexing agent. The raw signal is transmitted to the central processing unit through an isolation transmitter. During this process, the system performs baseline calibration and smoothing and noise reduction on the collected spectral signal to improve the signal-to-noise ratio in complex fluid backgrounds.

[0026] The multidimensional operating environment parameters include the macroscopic concentration of the main salt, the macroscopic concentration of the complexing agent, temperature, pH value, dissolved oxygen concentration, and electroplating current.

[0027] The specific implementation steps of S1 are as follows: S11. To avoid bubble scattering and signal interference from strong fluid turbulence and gas evolution (such as cathode hydrogen evolution) in the main tank, a bypass microfluidic detection cell with extremely small dead volume is connected in parallel around the main electroplating tank. A multimodal sensor array is integrated into this detection cell and the main return busbar, including: Deploy flow-through UV-Vis spectroscopy (UV-Vis) probes to capture characteristic absorption peaks of main salts such as gold and silver complex ions; deploy Raman spectroscopy (Raman) probes to capture molecular vibrational scattered photons of cyanide-free complexing agents such as sulfite and thiosulfate.

[0028] A strong alkali-resistant composite glass pH electrode and a fluorescence dissolved oxygen sensor are inserted into the steady-flow section of the detection cell to obtain the pH value. and dissolved oxygen concentration A PT100 high-precision resistance temperature sensor is mounted flush against the wall to obtain the absolute temperature of the current plating solution. .

[0029] Simultaneously, a closed-loop Hall current sensor is connected to the anode busbar of the DC power supply output to the main tank to extract the instantaneous electroplating current output by the power supply. .

[0030] S12. The electroplating workshop has strong electromagnetic interference (EMI) generated by high-frequency switching power supplies, and the sensor probe is in direct contact with strong electrolyte, which can easily form a ground loop and introduce common-mode noise. Therefore, the weak analog signals output by the above sensor array (such as the millivolt potential of the pH electrode and the microampere photocurrent of the spectrometer) are sent to an active low-pass filter to filter out high-frequency switching noise higher than the set cutoff frequency.

[0031] After analog-to-digital conversion (A / D), all digital signals are transmitted to the central processing unit via opto-isolated transmitters or fiber optic digital buses.

[0032] S13. After receiving the isolated and transmitted signal, the central processing unit converts the UV-Vis and Raman raw spectral signals into specific macroscopic concentration data and aligns them with environmental parameters using timestamps. The specific steps are as follows: Adaptive iterative weighted penalized least squares baseline calibration is performed on the received UV-Vis and Raman raw spectral signals to eliminate baseline shifts caused by light source drift and plating bath background turbidity, thus obtaining a pure absorbance / scattering intensity vector. .

[0033] Further, calculate the first Current macroscopically measured concentrations of the components (main salt or complexing agent) The specific formula is as follows:

[0034] in, for The preprocessed spectral feature column vector at each time step; For the first The regression weight coefficient vector corresponding to each component has the following dimensions: ; Let be the bias constant, with dimensions . .

[0035] S14. Due to the computational delay in spectral inversion calculation, the system uses the output timestamp of the spectral data as a reference to extract the environmental and process state parameters of the corresponding time node from the first-in-first-out (FIFO) historical circular queue, and packages them to generate a state parameter vector synchronized at the current moment.

[0036] In this embodiment 1, a multimodal sensor array is integrated into a bypass microfluidic detection cell with a very small dead volume connected in parallel around the main tank to avoid signal interference caused by fluid turbulence and gas evolution in the main tank. Combined with active low-pass filtering and photoelectric isolation transmission technology, strong electromagnetic interference and common-mode noise generated by high-frequency switching power supply are filtered out. At the same time, adaptive baseline calibration and FIFO timestamp alignment mechanism are used to improve the signal-to-noise ratio under complex fluid background, ensuring that the macroscopic concentration data retrieved by spectral inversion is synchronized with the multidimensional operating environment parameters in the time dimension, and generating a state parameter vector synchronized at the current moment.

[0037] Specifically, for example: during a sampling cycle in which the equipment is in a shutdown and heat preservation phase. At any given moment, the temperature sensor recorded the plating bath temperature as 45°C, and the composite glass pH electrode measured the real-time pH value. The dissolved oxygen concentration was 8.5, as measured by a fluorescence-based dissolved oxygen sensor. The concentration is 1.8 mg / L, and the instantaneous electroplating current is read by a closed-loop Hall current sensor. The value is 0A; simultaneously, the Raman spectroscopy probe collects the original molecular vibrational scattered photons of sulfite molecules. After adaptive iterative weighted penalized least squares baseline calibration by the central processing unit, the pure scattering intensity column vector is extracted. The system calls the sulfite weight coefficient vector. With bias constant The system calculates and outputs the current macroscopic concentration of free sulfite as 0.45 mol / L; subsequently, the system outputs the spectral data using the timestamp of this data. Based on this, the corresponding environmental and process state parameters, such as 45℃, pH 8.5, 1.8 mg / L, and OA, were precisely extracted from the first-in-first-out historical cycle queue and packaged to generate [data / data]. The synchronized state parameter vectors are aligned in real time, avoiding the problem of misalignment between spectral concentration and real-time environmental parameters caused by spectral computation delay.

[0038] As an optional embodiment: weight coefficient vector With bias constant The method for determining it is as follows: S131. In a laboratory environment or at the initial stage of a production line, a series of standard samples of cyanide-free electroplating solutions with known concentrations are manually prepared or extracted. The concentrations of the target components (such as the main salt or complexing agent) in these samples must exhibit a gradient distribution and completely cover the concentration process window and upper and lower limit anomalies that may occur in actual production. Simultaneously, to improve the robustness of macroscopic concentration calculations against interference in complex fluids, different concentrations of byproduct impurities must be cross-introduced into the standard sample set, and different operating temperatures and pH values ​​must be simulated.

[0039] S132. Using the UV-Vis and Raman sensors in the bypass microfluidic detection cell, each standard sample is spectrally scanned to obtain its raw spectral data containing the complete wavelength range, and preprocessing actions such as baseline calibration are performed. Simultaneously, high-precision traditional laboratory physicochemical analysis methods, such as precision chemical titration, are used to accurately determine the true absolute concentration of the target component in each standard sample.

[0040] S133. The preprocessed full-band spectral data is used as input features, and the corresponding true absolute concentration value is used as output label. The data is then imported into the central processing unit for machine learning training.

[0041] S134. During the iterative fitting process of the algorithm, the system will search for an optimal regression model in multidimensional space, minimizing the sum of squared errors between the concentration values ​​predicted by this regression model and the true concentration values ​​of the standard samples. The training process ends when this error converges and meets the preset cross-validation accuracy requirements. At this point, the correlation weight score assigned to each effective spectral band by the algorithm model is solidified into a weight coefficient vector. The overall offset of the algorithm model, which is used to align with the reference zero point and compensate for the inherent background noise of the device, is solidified into an offset constant. .

[0042] Weight coefficient vector With bias constant The parameters will be burned into the storage unit of the online detection controller as static firmware parameters. During the actual online operation of the production line, the system can directly call these two determined parameters to perform pure algebraic calculations on the unknown spectrum collected in real time, thereby instantly outputting the macroscopic concentration of the current plating solution.

[0043] S2. Establish a kinetic degradation assessment mechanism, quantify the latent losses in the non-energized state, and calculate the spontaneous kinetic degradation rate.

[0044] The specific implementation steps of S2 are as follows: S21. During the power-on initialization phase, the system reads the pre-stored apparent activation energy of the cyanide-free electroplating solution system. and pre-finger factors Based on the principles of reaction kinetics, using the current absolute temperature and apparent activation energy... The relative relationships between them are used to determine the proportion of activated molecules that can effectively decompose the complexing agent molecules under the current thermodynamic conditions, and this is combined with the pre-exponential factor. The real-time thermodynamic degradation rate constant reflecting the rate of spontaneous decomposition of the complexing agent at the current temperature was obtained. ; The obtained real-time thermodynamic degradation rate constant By characterizing the combined effect of the synergistic effect of the three factors on the total loss of the complexing agent, and relating it to the total working volume of the system and the currently measured macroscopic concentration of the complexing agent, a baseline thermodynamic degradation rate reflecting the spontaneous decomposition rate of the complexing agent in the entire electroplating system at the current temperature is determined. .

[0045] S22. During system operation, extract the dissolved oxygen oxidation reaction rate constant, which characterizes the irreversible chemical oxidation reaction between cyanide-free weak-field ligands and dissolved oxygen. Based on the currently collected dissolved oxygen concentration Rate constant of oxidation reaction with dissolved oxygen The correlation between them was used to determine the real-time oxidation attenuation factor that reflects the strength of the oxidation reaction under the current dissolved oxygen environment. ; Then the real-time oxidation attenuation factor The contribution of the synergistic effect of the total system working volume and the currently measured macroscopic concentration of free complexing agent to the total loss of the complexing agent is quantified as the increment of the oxidative degradation rate. .

[0046] S23. Extract the optimal process-stabilized pH value for the current cyanide-free electroplating solution system as pre-calibrated. and hydrolysis rate constant ; During system operation, based on the deviation between the current pH value and the optimal process stability pH value collected in real time, a real-time hydrolysis acceleration factor reflecting the catalytic effect of exponential changes in hydrogen ion concentration on the hydrolysis reaction is determined. ; Then the hydrolysis rate constant Real-time hydrolysis accelerator The contribution of the synergistic effect of the total system working volume, the currently measured macroscopic concentration of free complexing agent, and the total loss of complexing agent is quantified as the increment of hydrolysis degradation rate. .

[0047] S24. To address the interactions between the thermodynamic, oxidation, and hydrolysis pathways under specific conditions, an interaction coupling correction term is introduced. Quantitative compensation is performed. The specific logical steps are as follows: The system identifies the coupling relationships between three degradation pathways: thermodynamics and oxidation, thermodynamics and hydrolysis, and oxidation and hydrolysis. Based on the relative strength of their respective degradation rates, it determines whether there are interactive enhancement or interactive weakening effects. For each set of interactions, the system uses the harmonic average of the two degradation rates in that set as the basic characterization of the interaction strength, and combines it with the interaction coupling coefficient that has been experimentally calibrated in advance to quantify the net contribution of that set of interactions to the total degradation rate. The quantification results of the three sets of interactions are linearly superimposed to form a complete interaction coupling correction term. This is used to reflect the combined effect of multipath coupling on the total loss of the complexing agent.

[0048] S25, The above thermodynamic degradation rate baseline , Increment of oxidative degradation rate Incremental hydrolysis degradation rate and interactive coupling correction terms Perform linear superposition and multiply by the current macroscopic concentration of the complexing agent and the total working volume of the system to output the spontaneous kinetic degradation rate. .

[0049] In this embodiment, by calculating the implicit losses in the non-electro-energized state caused by thermodynamic spontaneous decomposition, dissolved oxygen oxidation consumption, and pH shift in the cyanide-free electroplating solution system, the loss of complexing agent is predicted, the lag of passive concentration feedback control is eliminated, and the risk of metal ion disproportionation autocatalysis in the cyanide-free system is suppressed.

[0050] Specifically, in the total working volume of the system Under the condition of shutdown and heat preservation of a 40L equipment (at which point there is no electrochemical reaction), the extraction is converted to thermodynamic absolute temperature. The apparent activation energy is 318.15 K, based on a pre-defined value. With pre-exponential factors The current thermodynamic degradation rate constant was evaluated. Combined with macroscopic concentration measurements Given a concentration of 0.45 mol / L, calculate the baseline thermodynamic degradation rate. The concentration was 0.012 mol / h; the real-time dissolved oxygen concentration was extracted. The concentration is 1.8 mg / L, combined with the preset dissolved oxygen oxidation reaction rate constant. Calculate the increment of oxidative degradation rate The extraction rate was 0.005 mol / h; real-time pH value was extracted. The value is 8.5, compared to the preset optimal process stability. The value was 9.0, and the increment of the hydrolysis degradation rate was calculated using a real-time hydrolysis acceleration factor. The value is 0.008 mol / h; output the spontaneous kinetic degradation rate at that moment. The value was 0.025 mol / h, which quantifies that under this heat preservation condition, free sulfite ions in the entire electroplating tank continued to be secretly lost at a rate of 0.025 mol / h.

[0051] As an optional embodiment: thermodynamic degradation rate baseline The calculation process is as follows: S211. During the power-on initialization phase, the system main controller reads the pre-stored physicochemical property parameters of the corresponding cyanide-free electroplating solution system from the local non-volatile memory and extracts the apparent activation energy of thermodynamic spontaneous decomposition. and pre-finger factors Simultaneously, the built-in ideal gas constant is invoked. ; During system operation, the temperature of the electroplating solution in Celsius is received in real time from the temperature sensor. And convert it into thermodynamic absolute temperature The specific conversion formula is as follows: = +273.15.

[0052] S212. Based on the principle of first-order reaction kinetics, a systematic evaluation is conducted at the current absolute temperature. The probability of spontaneous decomposition of cyanide-free complex molecules overcoming the energy barrier, specifically including: the extracted apparent activation energy. absolute temperature With the ideal gas constant Substitute the values ​​into the exponential term of the Arrhenius equation, calculate the proportion of activated molecules, and then multiply by the pre-exponential factor. The real-time thermodynamic degradation rate constant at the current moment is obtained. This can be specifically represented by the following formula: .

[0053] S213, Obtaining the real-time thermodynamic degradation rate constant Subsequently, in order to quantify the actual physical loss of free complexing agent in the current system, the main controller will use the real-time thermodynamic degradation rate constant. Total system working volume and the macroscopically measured concentration extracted in step S1 Perform a series of multiplication operations to output the base value of the thermodynamic degradation rate. This can be specifically represented by the following formula: ; Among them, the thermodynamic degradation rate base This reflects the rate at which the cyanide-free complexing agent in the entire electroplating tank and circulation pipeline spontaneously decomposes over time, even without electricity, at the current process temperature.

[0054] For example, apparent activation energy With pre-exponential factors The method for determining it is as follows: S211-a. Conduct accelerated aging experiments at multiple temperature gradients, including: preparing multiple sets of standard cyanide-free electroplating solution samples with the same initial concentration under a static, non-energized state; placing these samples in constant-temperature water baths or temperature-controlled chambers with different set values ​​for accelerated aging tests; periodically sampling samples at fixed time intervals within the set test period; and measuring the remaining concentration of free complexing agent in the plating solution at these times using spectroscopy or titration to obtain dynamic change data of complexing agent concentration decay over time at each specific temperature.

[0055] S211-b, Extract the real-time thermodynamic degradation rate constant at each specific temperature. This includes: processing the dynamic change data of concentration decay over time obtained above, and analyzing the rate of concentration decrease over time for each set isothermal test group. By mathematically fitting the concentration decay curve, the specific reaction rate constant for the spontaneous decomposition of the cyanide-free complex at that specific temperature is calculated.

[0056] S211-c. The obtained data pairs are mathematically transformed to construct an Arrhenius data mapping space. This includes: converting each recorded Celsius temperature to an absolute thermodynamic temperature and calculating its reciprocal, which is used as the horizontal axis data; simultaneously, calculating the natural logarithm of the reaction rate constant corresponding to each specific temperature, which is used as the vertical axis data. Projecting these transformed data points onto a two-dimensional Cartesian coordinate system, according to Arrhenius theory, these data points will exhibit a downward trend along a straight line with a negative slope.

[0057] S211-d: Perform least squares linear regression analysis on the data points in the two-dimensional rectangular coordinate system and draw the best-fit line.

[0058] The slope of the fitted straight line is extracted, reflecting the sensitivity of the complex decomposition reaction to temperature changes. The absolute value of this slope is then compared with the ideal gas constant. Multiplying them together, the result is determined as the apparent activation energy. It represents the minimum energy barrier that a cyanide-free complex molecule must overcome before it can spontaneously decompose.

[0059] The ordinate of the fitted line is extracted; that is, the ordinate value when the reciprocal of the temperature on the x-axis approaches zero, reflecting the theoretical molecular collision frequency of the system under extreme conditions. The value of this ordinate is then subjected to exponential reduction to determine the pre-exponential factor. .

[0060] The apparent activation energy obtained by the above method With pre-exponential factors As a constant parameter, it is pre-set in the system controller for direct use during online prediction.

[0061] As an optional embodiment, the oxidative degradation rate increment The steps to determine this are as follows: S221. The main controller extracts specific parameters characterizing the irreversible chemical oxidation reaction between cyanide-free weak-field ligands (such as sulfite or thiosulfate) and dissolved oxygen from the preset kinetic model configuration in the non-volatile memory; that is, the dissolved oxygen oxidation reaction rate constant. .

[0062] S222, The system will use the preset dissolved oxygen oxidation reaction rate constant. Compared with the current real-time dissolved oxygen concentration Perform a product operation to obtain the real-time oxidation attenuation factor specific to dissolved oxygen at the current moment. This can be specifically represented by the following formula: .

[0063] S223. To quantify the absolute loss of free complexing agent in the entire system's fluid network due to dissolved oxygen infiltration and circulating agitation, the main controller will calculate the real-time oxidation attenuation factor. Total system working volume and the current macroscopically measured concentration of free complexing agents Perform a series of multiplication operations to output the final increment of the oxidative degradation rate. This can be specifically represented by the following formula: ; In the formula, for The rate of degradation of free complexing agents caused by dissolved oxygen oxidation at all times.

[0064] For example, the dissolved oxygen oxidation reaction rate constant The method for determining it is as follows: S221-a. Prepare multiple sets of standard samples of cyanide-free electroplating solutions with identical initial components in the laboratory. In order to eliminate the interference of thermodynamic spontaneous degradation and hydrolysis reactions caused by pH shift on the test results, place all samples in the same and constant standard process temperature and optimal process pH environment, keep them in a static state without electricity throughout the process, and ensure that the free complexing agent in the system is only affected by the single variable of dissolved oxygen.

[0065] S221-b: Introduce mixed gases with different oxygen partial pressures into samples from different groups, such as using high-purity nitrogen and air mixed in different precise proportions for bubbling, to simulate various reoxygenation conditions that may occur in actual production lines.

[0066] After the gas dissolution in each group of samples reached dynamic gas-liquid equilibrium, a high-precision fluorescence dissolved oxygen sensor was used to measure and accurately record the stable absolute dissolved oxygen concentration in each group of sample systems.

[0067] S221-c. Within the determined testing period, samples are continuously taken from each group according to the preset sampling time interval, and the real-time residual concentration of free complexing agent in each sample is determined using online spectral analysis technology.

[0068] For each sample group, the dynamic evolution trajectory of its free complexing agent concentration over time was analyzed. By analyzing the initial slope of the concentration decay curve, the absolute concentration decrease rate under specific dissolved oxygen conditions was extracted. Since temperature and pH were strictly fixed, the extracted macroscopic concentration decrease rate represents the pure oxidative degradation rate.

[0069] S221-d: Using the dissolved oxygen concentration values ​​of each group of samples as the abscissa and the extracted oxidative degradation rate of the corresponding group as the ordinate, the data of multiple independent experiments are projected as scatter points in a two-dimensional rectangular coordinate system.

[0070] Based on the quasi-first-order dependence of oxidative degradation on dissolved oxygen concentration in chemical reaction kinetics, these scatter plots will exhibit a positively correlated linear upward trend starting from the origin. Subsequently, least squares linear regression analysis is performed on this set of scatter plots. The slope of the best-fit line reflects the ability of a unit concentration of dissolved oxygen to destroy free complexing agents per unit time, and the absolute value of the slope is solidified as the dissolved oxygen oxidation reaction rate constant. .

[0071] The rate constant of dissolved oxygen oxidation reaction It is stored in the non-volatile memory of the main controller and can be directly accessed when calculating the real-time oxidative degradation rate increment.

[0072] As an optional embodiment, the hydrolysis degradation rate increment The steps to determine this are as follows: S231. The main controller retrieves the pre-calibrated optimal process-stabilized pH value for the current cyanide-free electroplating solution system (such as sulfite or dimethylhydantoin system) from the system's non-volatile memory. and specific hydrolysis rate constant .

[0073] S232, Logarithmic definition based on pH value: The system assesses the exponential impact of pH shifts. This occurs when the plating bath absorbs carbon dioxide from the air or undergoes side reactions... As the concentration of free hydrogen ions in the system decreases, it increases exponentially by a factor of 10, thus accelerating the reaction of ligands (such as...) Combination generate Hydrolysis loss.

[0074] The system uses a base-10 value to calculate the difference between the optimal process-stabilized pH value and the current real-time pH value. The exponent is used to calculate the real-time hydrolysis acceleration factor at the current moment. This can be specifically represented by the following formula: .

[0075] S233. To quantify the absolute loss of free complexing agent caused by pH shift throughout the circulating fluid network, the main controller will preset the hydrolysis rate constant. Hydrolysis accelerating factor Total system working volume and the current macroscopically measured concentration of free complexing agents. Perform a series of multiplication operations to output the final increment of the hydrolysis degradation rate. This can be specifically represented by the following formula: ; In the formula, for The increment in the hydrolysis and degradation rate of free complexing agents caused by pH shift at any given moment.

[0076] For example, the optimal process stable pH value of the cyanide-free system With hydrolysis rate constant The method for determining it is as follows: S231-a. Prepare multiple sets of standard samples of cyanide-free electroplating solutions with identical initial components in the laboratory. In order to shield against cross-interference between thermodynamic degradation and oxidative degradation, place all samples at the same and constant standard process temperature, and continuously purify the sealed sample containers with high-purity inert gas (such as nitrogen) for deoxygenation protection to ensure that the free complexing agent in the system is only affected by pH value changes.

[0077] S231-b: Using high-purity reference acid or alkali solutions, adjust the above standard samples to different specific pH values ​​covering strong alkalinity to weak acidity to form a wide-range pH gradient test group.

[0078] Within a constant period, the residual concentration of the free complexing agent in each group of samples was sampled and measured frequently, and the absolute degradation rate of the complexing agent at each specific pH value was calculated. By comparing the data from all groups, the pH value corresponding to the point where the decay rate of the free complexing agent concentration reached its absolute minimum was identified. This pH value was then established as the optimal process stabilization pH value for this cyanide-free system. .

[0079] S231-c, Determining the optimal process stable pH value Subsequently, to quantify the catalytic effect of acidification shift on hydrolysis, standard samples were re-prepared, and their pH values ​​were artificially adjusted in a gradient to the optimal process-stable pH value. The following different levels simulate varying degrees of acidification and degradation. These acidified samples are continuously and dynamically monitored to extract the true accelerated degradation rate of the free complexing agent under different degrees of acidification deviation.

[0080] S231-d, Stabilize pH value using optimal process The actual adjusted pH values ​​of each group of samples recorded above. The difference was used as the x-axis, and the logarithm of the extracted true accelerated degradation rate for the corresponding group was used as the y-axis. Least square regression analysis was performed, and based on the fitted linear relationship, the inherent basic hydrolysis rate of the system under the optimal process stable pH was deduced, thus determining the hydrolysis rate constant. And it is burned as static firmware parameters into the non-volatile memory of the main controller.

[0081] As an optional embodiment, the interaction coupling correction term The calculation formula is as follows: ; in, These are the interaction coupling coefficients between thermodynamics and oxidation, thermodynamics and hydrolysis, and oxidation and hydrolysis, respectively. It is a preset minimum positive number used to avoid zero values ​​in the denominator.

[0082] For example, The method for determining it is as follows: S241. Design and execute a bivariate crossover accelerated aging experiment, including: preparing multiple groups of cyanide-free electroplating solution standard samples with the same initial concentration, and dividing them into three bivariate crossover experimental groups using the controlled variable method: Thermodynamic and oxidation (TO) coupled experimental group: The pH value of the sample was set at the optimal process stable pH value to eliminate the interference of hydrolysis reaction, and then multiple different combinations of absolute temperature and dissolved oxygen concentration gradients were set to accelerate aging.

[0083] Thermodynamic threshold hydrolysis (TH) coupled experimental group: In a sealed, oxygen-deprived environment with high-purity inert gas introduced to eliminate interference from oxidation reactions, multiple different combinations of absolute temperature and pH gradients were set to accelerate aging.

[0084] Oxidation and hydrolysis (OH) coupling experimental group: The system temperature was set at a constant standard reference temperature to maintain a constant baseline for thermodynamic degradation, and multiple different combinations of dissolved oxygen concentration and pH gradient were set to accelerate aging.

[0085] S242. Extract the actual macroscopic total degradation rate for each experimental combination, including: extracting samples frequently within the test period of each accelerated aging experiment, and determining the real-time residual concentration of the free complexing agent using spectral analysis. For each specific bivariate experimental condition, analyze the dynamic evolution trajectory of concentration decay over time, calculate and extract the actual macroscopic total degradation rate under that specific condition, denoted as... .

[0086] S243. Using the pre-calibrated basic linear degradation model of the system, calculate the theoretical independent degradation rate components of each experimental sample under corresponding environmental conditions, and remove them from the actual macroscopic total degradation rate to isolate the actual coupled degradation rate increment caused purely by the synergistic or inhibitory effects of the two factors. .

[0087] For the TO experimental group: calculate the corresponding baseline thermodynamic degradation rate. With the increase in oxidative degradation rate Extract the actual coupling increment .

[0088] For the TH experimental group: Calculate the corresponding baseline thermodynamic degradation rate. With the increase in hydrolysis degradation rate Extract the actual coupling increment .

[0089] For the OH experimental group: calculate the corresponding oxidative degradation rate increment. With the increase in hydrolysis degradation rate Extract the actual coupling increment ,in This represents the substrate loss at a constant temperature.

[0090] S244, Separate the actual coupled degradation rate increment As the target observation label, the corresponding theoretical independent degradation rate component is used as the input feature parameter to construct nonlinear target fitting functions.

[0091] Substitute the dataset of group TO into the formula. The nonlinear least squares method is used to optimize parameters and find the parameter solution that minimizes the sum of squared global residuals. .

[0092] Substitute the dataset of group TH into the formula Perform the same iterative optimization process to determine .

[0093] Substitute the dataset of group OH into the formula Perform the same iterative optimization process to determine .

[0094] As an optional embodiment, the spontaneous kinetic degradation rate The specific calculation formula is as follows: .

[0095] S3. Based on the electroplating process status, calculate the electrochemical Faraday consumption rate using Faraday's law for decoupling.

[0096] The specific implementation steps of S3 are as follows: S31. During the power-on initialization phase of the underlying program, the main controller calls the internationally recognized Faraday constant from the core code library. Simultaneously, based on the current cyanide-free electroplating solution formula type (such as monovalent gold sodium sulfite system) entered by the operator through the human-machine interface (HMI), the system extracts the electron transfer number of the corresponding main salt metal ion reduction reaction from the process database in non-volatile memory. .

[0097] In cyanide-free electroplating systems, due to the unavoidable presence of minor side reactions such as hydrogen evolution at the cathode, the effective charge for targeted component deposition is not 100%. The main controller invokes a pre-calibrated and stored multi-segment mapping table of current density and current efficiency in the system configuration, utilizing the instantaneous electroplating current. Divide the current by the total effective plating area of ​​the wafers recorded in the current batch to calculate the real-time cathode current density; then, using a linear interpolation algorithm in the multi-segment mapping table, dynamically address and extract the true cathode current efficiency of the target component under the current operating conditions. .

[0098] Specifically, the current density-current efficiency multi-segment mapping table can be constructed using the following method: Experiments are conducted under simulated actual electroplating conditions using a rotating disk electrode or Hall effect cell. A series of cathode current density gradients covering the process window are set, and the actual mass or power consumption of the target metal deposition at each current density is measured. The corresponding true cathode current efficiency is then inferred using Faraday's law. The measured current density and current efficiency data points are then subjected to piecewise linear fitting or interpolation to form a multi-segment mapping table, which is pre-stored in the system's non-volatile memory. In actual operation, the system dynamically extracts the current efficiency under the current operating condition based on the real-time cathode current density through table lookup and linear interpolation, which is then used for subsequent calculations of the electrochemical consumption rate.

[0099] S32, the main controller is based on instantaneous electroplating current. The cathode current efficiency obtained by combining dynamic mapping The effective charge flux per unit time that is actually used to drive the cathodic reduction deposition of the target component is evaluated. Retrieve the Faraday constant set at the system's underlying level And combined with the number of electrons transferred in the reduction reaction of the extracted corresponding components Establish a baseline threshold in the underlying logic; The effective reaction charge flux obtained from the assessment was projected onto the reaction charge equivalent benchmark of a single mole of target material for quantification and calculation, and the electrochemical Faraday consumption rate caused by cathode deposition and hydrogen evolution side reactions was calculated. This can be specifically represented by the following formula: .

[0100] In this Example 1, the electrochemical Faraday consumption rate caused by the cathode deposition and hydrogen evolution side reaction was calculated based on the operating environment parameters and the electroplating process status. Specifically, for example: in a certain batch of wafer-level TSV gold sulfite-free electroplating process, the system extracts the instantaneous electroplating current at the current moment. The current is 15A. At this point, based on the total effective plating area of ​​the wafer entered through the user interface, the system calculates the real-time cathode current density to be 1.5A. Assuming the current system uses monovalent gold sodium sulfite, the main controller extracts the electron transfer number of the gold ion reduction reaction from the bottom layer. =1, and Faraday constant 96485 The system extracts the true cathode current efficiency at a specific current density by dynamically addressing a pre-calibrated multi-segment mapping table and performing linear interpolation. The value is 92%, or 0.92, indicating that 8% of the electricity is consumed by parasitic side reactions such as hydrogen evolution. The electrochemical Faraday consumption rate is calculated. Approximately The cost is approximately 0.515 based on working hours. .

[0101] S4. By combining the spontaneous kinetic degradation rate and the electrochemical Faraday consumption rate, feedforward compensation and feedback correction are performed to construct a supplementary acceleration rate prediction model and calculate the final supplementary acceleration rate control quantity.

[0102] The specific implementation steps of S4 are as follows: S41, The spontaneous kinetic degradation rate output by S2 The term is used as an independent feedforward compensation, along with the electrochemical Faraday consumption calculated by S3. The terms are algebraically superimposed to obtain the predictive feedforward total consumption rate.

[0103] S42, Setting the... Target concentration of each component in the process Calculate the concentration deviation value at the current moment. Introducing a closed-loop proportional feedback gain coefficient. With integral gain coefficient Calculate the PI feedback correction amount Furthermore, to prevent the integral term from accumulating infinitely due to the integrated command exceeding the mechanical limit frequency of the metering pump when the system encounters large disturbances, a dynamic limit-reduction integral logic is introduced. Specific PI feedback correction amounts... The calculation formula is as follows: ; In the formula, This is the dynamic anti-saturation coefficient. When the theoretical control pulse frequency of the previous sampling period does not trigger the system's hard boundary saturation limiting, =1; when the maximum safe operating frequency is reached or exceeded And the current deviation When >0, =0, the system forcibly suspends the points accumulation process.

[0104] S43. Add the predictive feedforward total consumption rate to the feedback correction amount to construct the acceleration prediction model, and output the result for the first... The rate of acceleration control of each component This can be specifically represented by the following formula: .

[0105] In this embodiment 1, the spontaneous kinetic degradation rate is... With electrochemical Faraday consumption rate Algebraic superposition yields a predictive feedforward control benchmark encompassing both electrochemical and non-electrochemical dimensions. A PI feedback correction mechanism with dynamically limited integral logic is introduced to construct a rate-compensation prediction model, outputting a prediction model for the first... The rate of acceleration control of each component Through feedforward control, the basic compensation amount can be output proactively and without lag before the concentration of the target component drops substantially.

[0106] Specifically, for example: during normal operation of the electroplating production line, the system receives spontaneous kinetic degradation rates. The rate was 0.025 mol / h, and the electrochemical Faraday consumption rate was... The rate is 0.515 mol / h, and the algebraic superposition of the two yields a predictive feedforward total consumption rate of 0.540 mol / h. Assume the system reads the preset process target concentration. The concentration is 0.50 mol / L, compared to the current macroscopically measured concentration. The concentration is 0.45 mol / L. The concentration deviation at the current moment is calculated. The concentration is 0.05 mol / L. The closed-loop proportional feedback gain coefficient configured at the lower level is invoked. With integral gain coefficient The PI feedback correction amount for the current period is calculated. The value is 0.015 mol / h. At this point, the system determines that the theoretical control pulse frequency of the previous sampling period did not trigger the system's hard boundary saturation limiting, and sets the dynamic anti-saturation coefficient to 0.015 mol / h. Keeping the value at 1, calculate and output the compensating acceleration control value for this component. It is 0.555 mol / h.

[0107] For example, the closed-loop proportional feedback gain coefficient With integral gain coefficient The method for determining it is as follows: S421. With the electroplating equipment in a stable, non-energized, circulating, and heat-preserving state, lock the metering pump assembly's replenishment drive command at an extremely low, constant reference output to maintain a relatively stable free complexing agent concentration within the system. Subsequently, issue a step surge command of known fixed amplitude to the metering pump. .

[0108] S422. Utilize an online analysis system to continuously monitor macroscopic concentration changes of the target component at high frequency. Extract the pure time lag from command issuance to the actual onset of concentration data. Simultaneously, the time required for the system to reach a new stable concentration plateau was recorded, and the maximum rate of change (slope) of the concentration response curve was calculated. .

[0109] S423, Extracting the Static Amplification Factor of a System Based on a Step Response Curve ;in This represents the steady-state change in concentration.

[0110] S424, combined with static amplification factor Lag time With the maximum rate of change Calculate and obtain the proportional gain With integration time constant Ultimately, the decision was made. The reciprocal of The product is determined as the integral gain coefficient. And it is configured and embedded in the underlying logic of the main controller.

[0111] S5, The main controller receives the acceleration compensation control quantity. Then, based on the concentration of the original replenishing solution, it is converted into control command pulses to drive the metering pump assembly, injecting the replenishing solution into the circulation pipeline.

[0112] The specific implementation steps of S5 are as follows: S51, The main controller retrieves the data for the first [item] from the system's non-volatile memory. The concentration of the pre-prepared replenishment solution for each component And the corresponding volumetric pulse constant of the high-precision stepper metering pump. With maximum safe operating frequency .

[0113] S52, Due to the acceleration control quantity This characterizes the molar consumption rate of the target component by the system, which the main controller divides by the concentration of the replenishing solution. Calculate the real-time volumetric replenishment flow rate required by the system. The specific calculation formula is as follows: .

[0114] S53. Execution instruction pulse conversion and boundary constraints, including: The main controller will calculate the real-time volume supplement flow. Multiply by the pump's volumetric pulse constant This is converted into a theoretical control pulse frequency.

[0115] Meanwhile, to prevent non-physical negative values ​​or overflow errors exceeding the pump's mechanical limits caused by sudden changes in sensor signals, instantaneous algorithm anomalies, or negative feedback overshoot, the system adjusts the theoretical command pulse frequency of the output. The hard boundary saturation limiting constraint is applied using the following formula:

[0116] Among them, the volume pulse constant This represents the number of pulses required for the metering pump to pump 1 liter of liquid.

[0117] S54, the main controller's underlying pulse frequency modulation (PFM) module modulates the pulse frequency of the final generated safety command. Output a hardware square wave signal to drive the corresponding step metering pump to inject the corresponding replenishing fluid into the circulation pipeline.

[0118] In this embodiment, the received acceleration control quantity is used. And in combination with the concentration of the original supplemental solution The acceleration control amount will be supplemented. Converted into control command pulse frequency to drive metering pump components Add replenishing fluid to the circulation pipeline.

[0119] Specifically, for example: the system main controller receives the acceleration control quantity output by the front-end module. for (approximately 0.555) Subsequently, the stock solution concentration pre-prepared for gold sulfite replenishment was extracted from the non-volatile memory. It is 1.5 Calculate the required real-time volumetric replenishment flow rate. Approximately The system extracts the volumetric pulse constant of this high-precision stepper metering pump. 1000 pulses Add flow rate to the volume This is converted into a theoretical control pulse frequency, i.e. At this point, the system calls the preset maximum safe operating frequency. It is 5.0. Boundary assessment of the theoretical value: due to 1.027 lie in Within a safe and effective operating range, the limiting function outputs the final safety command pulse frequency. It is 1.027 The underlying pulse frequency modulation module then converts this value into a corresponding hardware square wave signal, smoothly driving the metering pump to inject replenishment fluid into the circulation pipeline.

[0120] Example 2 As a second embodiment of the present invention, such as Figure 3As shown, based on Embodiment 1, an electroplating apparatus for advanced semiconductor packaging is also disclosed, specifically including: a main electroplating tank, a circulation pipeline, a bypass microfluidic detection cell, a multimodal sensor array, a stepper metering pump, and the online analysis and replenishment control system for the cyanide-free electroplating solution for semiconductor packaging described in Embodiment 1. The online analysis and replenishment control system is electrically connected to the multimodal sensor array and the stepper metering pump, and outputs a safety command pulse frequency by calculating it. Control the step metering pump to precisely inject replenishment fluid into the circulation pipeline.

[0121] In the wafer-level electroplating workshop, the TSV and Micro-bump stations utilize multiple parallel electroplating tanks for cyanide-free electroplating operations. During equipment shutdown for heat preservation or electroplating solution circulation standby, the parameter acquisition and concentration extraction module of the online analysis and replenishment control system collects operating environment parameters in real time through a multimodal sensor array, including absolute temperature. pH value and dissolved oxygen concentration The macroscopic concentration of the cyanide-free complexing agent was simultaneously extracted using a bypass microfluidic detection cell. .

[0122] Subsequently, the kinetic decay assessment module, based on the collected operating environment parameters and macroscopically measured concentrations, Calculate the baseline thermodynamic degradation rate respectively. , Increment of oxidative degradation rate With the increase in hydrolysis degradation rate Combined with the interaction coupling correction term Output the quantized spontaneous kinetic degradation rate It actively compensates for the latent losses of the complexing agent in the non-energized state.

[0123] After entering the micro-current packaging stage, the system extracts the instantaneous electroplating current through a Hall current sensor connected to the anode busbar. The Faraday consumption calculation module is based on the instantaneous electroplating current. Combined with the pre-extracted true cathode current efficiency Calculate the electrochemical Faraday consumption rate caused by cathode deposition and hydrogen evolution side reactions. .

[0124] The acceleration prediction model building module will use the spontaneous kinetic degradation rate... As an independent feedforward compensation, it is related to the electrochemical Faraday consumption rate. Superimposed, and combined with the current concentration deviation of the system. Calculated closed-loop feedback correction amount Output comprehensive acceleration control quantity .

[0125] Finally, the control command conversion module combines the concentration of the replenishing solution stock solution. The acceleration control amount Converted into the safety command pulse frequency driving the stepper metering pump assembly The corresponding concentration of replenishing solution is precisely injected into the circulation pipeline, thereby avoiding metal ion disproportionation autocatalysis caused by simply relying on passive feedback lag, and ensuring the long-term stability and yield of semiconductor high-precision packaging process.

[0126] To further verify the effectiveness of the online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging proposed in Example 1 of this invention, a comparative experiment was conducted for 168 hours, including alternating periods of normal production and standby heat preservation, using the traditional pure ampero-hour meter method, the traditional spectral concentration feedback method, and the control system of this invention. A target concentration of sulfite (complexing agent) was set. It is 0.50 mol / L. Specifically: Comparison of complexing agent concentration fluctuation and replenishment response time: The system records the evolution trajectory of the macroscopic measured concentration of free complexing agent over time under three control methods using an online analyzer, and statistically analyzes the system replenishment response time when the concentration decays, as shown in Table 1 below.

[0127] Table 1: Statistics on Complexing Agent Concentration Fluctuation and Supplementation Response Time

[0128] As shown in Table 1, the traditional pure ampero-hour meter method, relying solely on the electrochemical consumption of the current, cannot issue feedforward replenishment commands for hidden losses caused by thermodynamic instability and dissolved oxygen oxidation during equipment shutdown for heat preservation or low-current encapsulation. This results in the complexing agent concentration dropping to 0.32 mol / L during shutdown, easily triggering irreversible disproportionation autocatalytic reactions of metal ions within the system. The traditional spectral concentration feedback method relies on a passive feedback mechanism, triggering replenishment only when a large amount of free complexing agent is lost and the concentration falls below the set process threshold, with a response time of 2 to 5 minutes, leading to significant sawtooth fluctuations in the actual concentration curve. In contrast, the control system of this invention utilizes the spontaneous kinetic degradation rate... With electrochemical Faraday consumption rate By combining feedforward compensation and feedback correction, the system can simultaneously calculate the real-time physical and chemical consumption rate within 10 to 30 seconds of the control cycle and continuously issue control command pulse frequencies, so that the transient consumption of the metering pump and the plating solution maintains high-frequency dynamic coordination. Even in the heat preservation state without electrochemical reaction, the system can still actively output replenishment commands corresponding to the degradation rate, keeping the concentration fluctuation range within 0.02 mol / L throughout the entire cycle.

[0129] Comparison of Coating Thickness Uniformity and Process Yield: For wafer-level micro-bump packaging technology, after the experimental cycle, 500 wafers from each batch were randomly selected (for each method). Bump height and coating thickness were measured using a white light interferometer, and the overall process yield was statistically analyzed using AOI (Automated Optical Inspection) equipment. The yield criteria were: no internal voids, no surface nodules, and a wafer-level bump height difference of <3%. The experimental results are shown in Table 2 below.

[0130] Table 2: Statistics on Micro-bump Thickness Uniformity and Process Yield

[0131] As shown in Table 2, after adopting the control system of this invention, the standard deviation of the micro-bump height decreased from 0.92 to 1.85 compared to the traditional method. Converged to 0.21 The in-wafer thickness non-uniformity (WIWNU) was controlled within 1.5%, and the final process yield was improved to 99.6%. This broke the limitations caused by the lack of feedforward compensation for non-electrochemical consumption and the superposition of passive feedback lag, and significantly improved the long-term stability and process yield of cyanide-free electroplating solution in high-precision semiconductor packaging.

[0132] The preferred embodiments of the invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. An online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging, characterized in that, include: The parameter acquisition and concentration extraction module is used to acquire operating environment parameters and simultaneously extract macroscopic concentration data during the electroplating solution circulation process. The kinetic degradation assessment module quantifies the latent losses in the non-energized state and calculates the spontaneous kinetic degradation rate based on the operating environment parameters and the macroscopic concentration data. The Faraday consumption calculation module calculates the electrochemical Faraday consumption rate caused by cathode deposition and hydrogen evolution side reactions based on the operating environment parameters and the electroplating process status. The accelerated rate prediction model construction module is used to combine the spontaneous kinetic degradation rate and the electrochemical Faraday consumption rate for feedforward compensation and feedback correction, construct the accelerated rate prediction model and calculate the accelerated rate control quantity. The control command conversion module is used to receive the replenishment rate control quantity and, in combination with the concentration of the replenishment liquid stock solution, convert the replenishment rate control quantity into the control command pulse frequency for driving the metering pump assembly, and inject the replenishment liquid into the circulation pipeline.

2. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 1, characterized in that, The specific steps of the parameter acquisition and concentration extraction module include: Multidimensional operating environment parameters are collected during the electroplating solution circulation process using a sensor array. These operating environment parameters include at least temperature, pH value, dissolved oxygen concentration, and electroplating current. The raw spectral signal containing the main salt and complexing agent is acquired and processed to eliminate baseline shift and background interference, and to extract pure spectral feature vectors. By combining the spectral feature vector with the pre-calibrated weighting coefficients and bias constants, the macroscopic concentration data of the main salt and complexing agent at the current moment are extracted; Based on the output timestamp of the spectral data, the environmental and process status parameters of the corresponding time node are matched in the historical data queue to generate a synchronized status parameter vector.

3. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 1, characterized in that, The specific steps for calculating the spontaneous kinetic degradation rate by the kinetic decay assessment module include: Based on the apparent activation energy, pre-exponential factor, and current absolute temperature of the cyanide-free electroplating solution system, a real-time thermodynamic degradation rate constant reflecting the spontaneous decomposition rate of the complexing agent is determined; and the real-time thermodynamic degradation rate constant, the total working volume of the system, and the macroscopic concentration of the complexing agent are correlated and quantified into a thermodynamic degradation rate base. Based on the real-time collected dissolved oxygen concentration and the preset dissolved oxygen oxidation reaction rate constant, a real-time oxidation attenuation factor reflecting the strength of the oxidation reaction is determined; and the real-time oxidation attenuation factor, the total working volume of the system, and the macroscopic concentration of the free complexing agent are correlated and quantified as the increment of the oxidation degradation rate. Based on the deviation of the current pH value from the optimal process stable pH value, the catalytic effect of hydrogen ion concentration change on the hydrolysis reaction is evaluated to determine the real-time hydrolysis acceleration factor; and the hydrolysis rate constant, real-time hydrolysis acceleration factor, total system working volume and macroscopic concentration of free complexing agent are correlated and quantified as the hydrolysis degradation rate increment. An interactive coupling correction term is introduced, and the spontaneous kinetic degradation rate is determined by combining the synergistic contributions of the thermodynamic degradation rate base, the oxidative degradation rate increment, and the hydrolytic degradation rate increment to the total loss of the complexing agent.

4. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 3, characterized in that, The process of determining the apparent activation energy and pre-exponential factor includes: The dynamic change data of complexing agent concentration decay over time at various specific temperatures in the isothermal accelerated aging experiment were obtained, and the specific reaction rate constant at each specific temperature was extracted. A two-dimensional data mapping space based on the reciprocal of absolute temperature and the natural logarithm of the reaction rate constant is constructed, and the characteristic parameters of the fitted line are extracted through linear regression analysis. The apparent activation energy is determined by combining the slope of the fitted line with the ideal gas constant, and the pre-exponential factor is determined by performing an exponential reduction operation based on the ordinate of the fitted line.

5. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 3, characterized in that, The process of determining the preset constant in the increment of the oxidative degradation rate and the increment of the hydrolytic degradation rate includes: The dissolved oxygen oxidation reaction rate constant was determined by constructing a positive linear correlation between different absolute dissolved oxygen concentrations and the corresponding oxidative degradation rates, and extracting the slope of the best-fit line. The hydrolysis rate constant is determined by inversely extrapolating the basic hydrolysis rate through the linear relationship between the difference between the optimal process stable pH value and the actual acidification adjusted pH value and the corresponding logarithm of the accelerated degradation rate.

6. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 1, characterized in that, The specific steps for calculating the electrochemical Faraday consumption rate using the Faraday consumption calculation module include: Extract the number of electrons transferred in the reduction reaction of the corresponding target component; The real-time cathode current density is calculated based on the instantaneous electroplating current and the total effective electroplating area, and the true cathode current efficiency is extracted by dynamic addressing according to the mapping table configured in the system. The effective reactive charge flux is evaluated based on a comprehensive assessment of the instantaneous electroplating current and the actual cathode current efficiency. The effective reaction charge flux is projected onto a reaction charge equivalent benchmark established by combining the number of electron transfers and the Faraday constant for quantification and conversion to obtain the electrochemical Faraday consumption rate.

7. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 1, characterized in that, The specific operation steps of the acceleration prediction model construction module include: The spontaneous kinetic degradation rate is used as an independent feedforward compensation term, and combined with the electrochemical Faraday consumption rate, the predictive feedforward total consumption rate is comprehensively evaluated. Based on the deviation between the process target concentration and the current macroscopically measured concentration, the closed-loop feedback correction amount is determined by combining the closed-loop proportional feedback gain coefficient and the integral gain coefficient. By combining the predictive feedforward total consumption rate and the closed-loop feedback correction, the acceleration prediction model is constructed to output the acceleration control quantity. In calculating the feedback correction amount, a dynamic limit weakening integral logic is introduced: when the theoretical control command triggers the system's hard boundary saturation limit and the concentration deviation is positive, the cumulative action of the integral term is forcibly truncated.

8. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 3, characterized in that, The process of determining the interaction coupling correction term includes: The system identifies the coupling relationships between three degradation pathways: thermodynamics and oxidation, thermodynamics and hydrolysis, and oxidation and hydrolysis. Based on the relative strength of their respective degradation rates, it determines whether there are interactive enhancement or interactive weakening effects. For each set of interactions, the harmonic average of the two degradation rates in each set is used as the basic characterization of the interaction strength, and combined with the pre-calibrated interaction coupling coefficient, the net contribution of each set of interactions to the total degradation rate is quantified. The quantitative results of the three sets of interactions—thermodynamics and oxidation, thermodynamics and hydrolysis, and oxidation and hydrolysis—are linearly superimposed to form a complete interaction coupling correction term, which is used to reflect the comprehensive impact of multipath coupling on the total loss of the complexing agent.

9. The online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging according to claim 1, characterized in that, The specific operation steps of the control command conversion module include: Based on the proportional mapping relationship between the replenishment rate control quantity and the concentration of the replenishment solution stock solution, the molar consumption rate of the target component is converted into the real-time volume replenishment flow rate required by the system. The volumetric replenishment flow rate is scaled using the volumetric pulse constant of the metering pump to generate a theoretical control pulse frequency; Based on the set maximum safe operating frequency, a hard boundary saturation limiting constraint is applied to the theoretical control pulse frequency, and a safe command pulse frequency is output. The underlying modulation module generates a hardware square wave signal based on the frequency of the safety command pulse, which drives the metering pump to inject replenishment liquid into the circulation pipeline.

10. Electroplating equipment for advanced semiconductor packaging, characterized in that, Specifically, it includes: The system comprises an electroplating main tank, a circulation pipeline, a bypass microfluidic detection cell, a multimodal sensor array, a stepper metering pump, and an online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging as described in any one of claims 1 to 9, wherein the online analysis and replenishment control system for cyanide-free electroplating solution composition for semiconductor packaging is electrically connected to the multimodal sensor array and the stepper metering pump, respectively. The multimodal sensor array collects operating environment parameters and macroscopic concentration data in real time, and calculates and outputs command pulse frequency to drive the stepper metering pump to accurately inject supplementary liquid into the circulation pipeline.

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