Electroplating bath composition detection method and system based on spectroscopy

Abstract

The present application relates to the technical field of spectral data processing, in particular to a plating solution component detection method and system based on spectral technology. The present application obtains candidate continuous wave bands; according to the distribution of absorbance corresponding to different wavelengths in each candidate continuous wave band and the absorbance stability distribution of different wavelengths, a reference scattering wave band is screened out; for any concentration, according to the detection spectrum at each moment and the absorbance distribution of different wavelengths in the reference scattering wave band, the initial corrected absorbance of each wavelength at each moment is obtained; according to the initial corrected absorbance distribution of each wavelength at the corresponding moment of different temperatures, the temperature correction coefficient of each wavelength is obtained; combined with the difference between the real-time temperature and the preset reference temperature, the final corrected absorbance of each wavelength is obtained, and the component of the plating solution is detected. The present application accurately obtains the final corrected absorbance after removing scattering and temperature fluctuation, and improves the precision of plating solution component detection.

Description

Technical Field

[0001] This invention relates to the field of spectral data processing technology, and specifically to a method and system for detecting the composition of electroplating solutions based on spectral technology. Background Technology

[0002] Electroplating, as an important surface treatment process, is becoming increasingly important as modern manufacturing moves towards higher precision and reliability. In particular, in high-tech electroplating processes such as printed circuit boards (PCBs), semiconductor packaging, and precision connectors, the uniformity of plating thickness and the accuracy of its composition directly determine the performance and yield of the final product. The quality of the plating layer fundamentally depends on the chemical composition of the electroplating solution, including whether the concentrations of main salt metal ions, conductive salts, buffers, and various additives are within a strict process control window.

[0003] In existing technologies, although near-infrared and ultraviolet online detection systems using atomic spectroscopy to detect the composition of electroplating solutions achieve continuous sampling, the composition of electroplating solutions is complex, with severe light scattering effects. The presence of microbubbles, suspended solid particles, or impurities with different refractive indices in the solution causes the collected spectral information to contain nonlinear information, interfering with the characteristic absorption of the components. Furthermore, temperature fluctuations can also cause spectral baseline drift, resulting in a significant decrease in model prediction accuracy, insufficient robustness, and low component detection efficiency. Summary of the Invention

[0004] To address the technical problems of severe light scattering effects and temperature fluctuations leading to low component detection efficiency, the present invention aims to provide a method and system for component detection in electroplating solutions based on spectral technology. The specific technical solution adopted is as follows: This invention proposes a method for detecting the composition of electroplating solutions based on spectroscopic technology, the method comprising: The detection spectra and temperature data of the electroplating solution at different concentrations were obtained in sequence over time. The spectra included absorbance corresponding to different wavelengths. For any given time, the absorbance stability of each wavelength is obtained based on the absorbance distribution at all concentrations; candidate continuous bands are obtained outside the wavelength range of the characteristic absorption peaks in the detection spectrum; the spectral smoothness of each candidate continuous band is obtained based on the absorbance distribution corresponding to different wavelengths in each candidate continuous band; and reference scattering bands are selected based on the spectral smoothness of each candidate continuous band and the absorbance stability distribution at different wavelengths. For any concentration, the initial corrected absorbance of each wavelength at each moment is obtained based on the detection spectrum at each moment and the absorbance distribution of different wavelengths in the reference scattering band; the temperature correction coefficient of each wavelength is obtained based on the initial corrected absorbance distribution of each wavelength at different temperatures; and the final corrected absorbance of each wavelength at each concentration is obtained based on the initial corrected absorbance of each wavelength, the temperature correction coefficient, and the difference between the real-time temperature and the preset reference temperature. Based on the final corrected absorbance at different wavelengths under different concentrations, a model for detecting the composition of electroplating solutions was constructed.

[0005] Furthermore, the method for obtaining the absorbance stability includes: For any given time, the absorbance fluctuation characteristics at each wavelength under all concentrations are obtained and negatively correlated, which is then used as the first stability coefficient. The value of each wavelength is divided by the value of the maximum wavelength, and this is used as the second stability coefficient. The product of the first stability coefficient and the second stability coefficient is obtained and normalized to obtain the absorbance stability for each wavelength.

[0006] Furthermore, the method for obtaining the candidate continuous bands includes: Continuous bands outside the wavelength range of the characteristic absorption peak in the detection spectrum are considered as candidate continuous bands.

[0007] Furthermore, the method for obtaining the spectral smoothness includes: Obtain the sequence of absorbance for all wavelengths within the candidate continuous band, and obtain the second-order difference sequence of the sequence. The mean of the squares of the elements in the second-order difference sequence is obtained and negative correlation mapping is performed as the spectral smoothness of each candidate continuous band.

[0008] Furthermore, the method for obtaining the reference scattering band includes: Based on the spectral smoothness of each candidate continuous band and the stable distribution of absorbance at different wavelengths, the scattering optimization score of each candidate continuous band is obtained. The candidate continuous band with the highest scattering optimization score among all candidate continuous bands is selected as the reference scattering band.

[0009] Furthermore, the method for obtaining the scattering preference score includes: The maximum value of spectral smoothness among all candidate continuous bands is obtained, and the ratio of the spectral smoothness of each candidate continuous band to the maximum value of spectral smoothness is obtained as the relative smoothness. The mean value of absorbance stability for all wavelengths within each candidate continuous band is obtained as the absorption stability level. The product of relative smoothness and absorption stability level is obtained as the scattering optimization score for each candidate continuous band.

[0010] Furthermore, the method for obtaining the initial corrected absorbance includes: Obtain the scattering curve function fitted by the absorbance of different wavelengths in the reference scattering band; The absorbance difference at each wavelength between the detection spectrum and the scattering curve function at each time step is obtained as the initial corrected absorbance for each wavelength.

[0011] Furthermore, the method for obtaining the temperature correction coefficient includes: For any wavelength, the initial corrected absorbance of each concentration at different temperatures at corresponding times is fitted with a straight line, and the slope of the fitted line is used as the temperature correction coefficient for each wavelength.

[0012] Furthermore, the method for obtaining the final corrected absorbance includes: For any concentration, obtain the temperature difference between the real-time temperature and the preset reference temperature, obtain the product of the temperature correction coefficient and the temperature difference for each wavelength, calculate the difference between the initial corrected absorbance and the product result for each wavelength, and use it as the final corrected absorbance for each wavelength at the corresponding concentration.

[0013] The present invention also proposes an electroplating solution composition detection system based on spectral technology, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the steps of the electroplating solution composition detection method based on spectral technology described above.

[0014] The present invention has the following beneficial effects: This invention obtains the absorbance stability of each wavelength based on the absorbance distribution at all concentrations, reflecting the significant degree of scattering variation with wavelength; it obtains candidate continuous bands outside the wavelength range of characteristic absorption peaks in the detection spectrum, narrowing the search range and ensuring that subsequent calculations are performed in the purely physical scattering region; based on the absorbance distribution corresponding to different wavelengths in each candidate continuous band, and the absorbance stability distribution at different wavelengths, a reference scattering band is selected, ensuring that the selected reference scattering band is a true, purely scattering window affected only by bubbles and particles; for any concentration, based on the detection light at each moment... This invention obtains the initial corrected absorbance for each wavelength at each time point by analyzing the absorbance distribution at different wavelengths in the spectrum and reference scattering band. The absorption spectrum contributing to scattering is then subtracted from the original detection spectrum. Based on the initial corrected absorbance distribution for each wavelength at different temperatures, a temperature correction coefficient is obtained for each wavelength, establishing a linear relationship between absorbance and temperature. Finally, based on the initial corrected absorbance, temperature correction coefficient, and the difference between the real-time temperature and the preset reference temperature, the final corrected absorbance for each wavelength at each concentration is obtained, further eliminating temperature interference and constructing a model for detecting the composition of electroplating solutions. This invention improves the accuracy of electroplating solution composition detection by accurately obtaining the final corrected absorbance after removing scattering and temperature fluctuations. Attached Figure Description

[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart of a method for detecting the composition of electroplating solution based on spectral technology, provided as an embodiment of the present invention. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a method and system for detecting the composition of electroplating solutions based on spectral technology proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] The following description, in conjunction with the accompanying drawings, details the specific scheme of the electroplating solution composition detection method and system based on spectral technology provided by the present invention.

[0020] Please see Figure 1 The diagram illustrates a flowchart of a method for detecting the composition of an electroplating solution based on spectral technology, according to an embodiment of the present invention, specifically including: Step S1: Obtain the detection spectrum and temperature data of the electroplating solution at different concentrations according to the time sequence. The spectrum includes the absorbance corresponding to different wavelengths.

[0021] In an embodiment of the present invention, the composition of the electroplating solution is detected by spectroscopic technology. During the dynamic production process, the scattering intensity of the electroplating solution changes rapidly over time, while the component concentration changes relatively slowly. In order to establish a reliable scattering correction model, it is necessary to analyze the spectral data under different scattering conditions, different component concentrations, and different temperatures. First, an online spectroscopic detection system is installed on the electroplating production line, which includes at least a spectrometer and a temperature sensor. A series of standard electroplating solutions with different concentrations are prepared, covering ±30% of the process window. The detection spectra and temperature data of the electroplating solutions at different concentrations are acquired in sequence. The spectra include the absorbance corresponding to different wavelengths.

[0022] It should be noted that, in the embodiments of the present invention, the consumption of the component concentration of the electroplating solution is a gradual process, but the scattering interference caused by the churning of the solution, bubbles and particles is a transient change. In order to keenly capture instantaneous scattering and temperature fluctuations, the time sequence indicates the order in which the time moments are acquired, and the interval between the time moments is set to 5 seconds to acquire the data at each time moment. In other embodiments of the present invention, the time interval can be set according to the specific situation, which will not be limited or described in detail here.

[0023] Step S2: For any given time, obtain the absorbance stability of each wavelength based on the absorbance distribution at all concentrations; obtain candidate continuous bands other than the wavelength range of the characteristic absorption peak in the detection spectrum; use the absorbance distribution of different wavelengths in each candidate continuous band as the spectral smoothness of each candidate continuous band; and select reference scattering bands based on the spectral smoothness of each candidate continuous band and the absorbance stability distribution at different wavelengths.

[0024] Absorbance reflects the energy attenuation of light after it passes through the electroplating solution. In the spectrum, scattering causes the absorbance curve to gradually rise from long wavelengths to short wavelengths, forming a specific background baseline. Since the absorbance caused by scattering is not simply added to the absorption of the components, when scattering is strong, the optical path length effectively increases, which may enhance certain absorption peaks, producing a multiplicative effect. This leads to distortion of the absorption peak shape, disproportionate increase in peak height, and peak position shift. The absorbance distribution reflects the changes in absorbance. The more consistent the absorbance changes, the more stable the energy attenuation at each wavelength, and the greater the possibility that it is only affected by scattering. The absorbance stability at each wavelength can be obtained by analyzing the absorbance distribution at all concentrations.

[0025] Preferably, in one embodiment of the present invention, the method for obtaining absorbance stability includes: The first step is to obtain the absorbance fluctuation characteristics of each wavelength at all concentrations at any given time and perform negative correlation mapping as the first stability coefficient. It should be noted that, in one embodiment of the present invention, the fluctuation characteristics are characterized by calculating the variance. The larger the variance, the larger the fluctuation characteristics and the more significant the absorption characteristics. The smaller the variance, the smaller the fluctuation characteristics and the more significant the lack of absorption characteristics. In other embodiments of the present invention, the fluctuation characteristics can also be characterized by the standard deviation or the range. The specific means are well known to those skilled in the art and will not be described in detail here.

[0026] It should be noted that, in some embodiments of the present invention, negative correlation mapping can be performed by taking the reciprocal. When taking the reciprocal, to avoid the formula being meaningless with a denominator of 0, a very small positive number with consistent dimensions is added to the denominator. The value of this number can be specifically set according to the range of values ​​of the denominator. In other embodiments of the present invention, an exponential function with the natural constant as the base can also be used. Negative correlation mapping is performed using techniques well-known to those skilled in the art, which will not be elaborated upon here.

[0027] The second step is to obtain the value of each wavelength divided by the value of the largest wavelength, which is used as the second stability coefficient. It should be noted that the closer each wavelength is to the maximum wavelength, the smoother the characteristic and the larger the stability coefficient. The third step is to obtain the product of the first stability coefficient and the second stability coefficient, and then normalize it to obtain the absorbance stability for each wavelength.

[0028] It should be noted that in some embodiments of the present invention, normalization is performed by linear normalization or a normalization function, such as maximum and minimum value normalization. For example, all wavelengths are analyzed, and the maximum and minimum values ​​of their product results are selected for maximum and minimum value normalization to the range of 0-1. The specific means are well known to those skilled in the art and will not be described in detail here.

[0029] In one embodiment of the present invention, the formula for absorbance stability is expressed as: ;in, Indicates wavelength Absorbance stability; Indicates wavelength at all concentrations The sequence composed of absorbance; Indicates wavelength at all concentrations The variance of absorbance, which reflects the wavelength... Absorbance fluctuation characteristics; Represents a very small positive number; Indicates the wavelength value; Indicates the maximum wavelength; This represents the normalization function.

[0030] In electroplating solutions, certain wavelength regions do not exhibit any characteristic absorption of any component, presenting a smooth shape without obvious peaks and valleys. This helps in analyzing the light absorption characteristics caused by scattering. Therefore, regions outside the wavelength range of characteristic absorption peaks are selected for analysis to obtain candidate continuous bands outside the wavelength range of characteristic absorption peaks in the detection spectrum.

[0031] It should be noted that, in the embodiments of the present invention, the wavelength range of the characteristic absorption peak is obtained in advance by prior knowledge, the peak position with the largest absorbance value in the spectrum and the positions of half of the absorbance peak on both sides are identified, and the continuous range between the half positions on both sides of the absorbance peak is determined as the wavelength range of the characteristic absorption peak; the continuous bands other than the wavelength range of the characteristic absorption peak in the detection spectrum are taken as candidate continuous bands.

[0032] Candidate continuous bands reflect other scattering bands besides the characteristic absorption peak. The absorbance at different wavelengths reflects the continuous variation of energy attenuation within the candidate continuous band. A smooth baseline drop caused only by scattering, with smaller and more uniform absorbance changes, indicates greater spectral smoothness. Conversely, the presence of small absorption peaks, noise interference, or residual absorption components results in larger and more discrete absorbance changes, leading to less spectral smoothness. The spectral smoothness of each candidate continuous band is obtained based on the distribution of absorbance at different wavelengths within that band.

[0033] Preferably, in one embodiment of the present invention, the method for obtaining spectral smoothness includes: Obtain the sequence of absorbance for all wavelengths within the candidate continuous band, and obtain the second-order difference sequence of the sequence. The mean of the squares of the elements in the second-order difference sequence is obtained and negative correlation mapping is performed as the spectral smoothness of each candidate continuous band.

[0034] It should be noted that, in the embodiments of the present invention, the absorbance sequence is subjected to second-order difference. The second-order difference reflects the change in absorbance. The larger the second-order difference, the greater the change in absorbance, the more uneven the distribution, and the smaller the spectral smoothness. The specific means are well known to those skilled in the art and will not be described in detail here.

[0035] It should be noted that, in the embodiments of the present invention, an exponential function with a base of the natural constant can be used. Negative correlation mapping can be performed; in other embodiments of the present invention, the reciprocal can also be used to perform negative correlation mapping. In order to avoid the denominator of the formula being 0 and the formula being meaningless, a very small positive number with the same dimensions is added to the denominator. The value of the number can be specifically set according to the range of the denominator, which will not be elaborated here.

[0036] Spectral smoothness reflects the degree of interference from absorption peaks, while absorbance stability reflects the significant change in scattering with wavelength. Combining both is beneficial for quantifying and analyzing bands that are less affected by interference and show significant changes with wavelength. Reference scattering bands are selected based on the spectral smoothness of each candidate continuous band and the absorbance stability distribution at different wavelengths.

[0037] Preferably, in one embodiment of the present invention, the method for obtaining the reference scattering band includes: Based on the spectral smoothness of each candidate continuous band and the stable distribution of absorbance at different wavelengths, the scattering optimization score of each candidate continuous band is obtained. Preferably, in one embodiment of the present invention, the method for obtaining the scattering preference score includes: The maximum value of spectral smoothness among all candidate continuous bands is obtained, and the ratio of the spectral smoothness of each candidate continuous band to the maximum value of spectral smoothness is obtained as the relative smoothness. The mean value of absorbance stability for all wavelengths within each candidate continuous band is obtained as the absorption stability level. The product of relative smoothness and absorption stability level is obtained as the scattering optimization score for each candidate continuous band.

[0038] In one embodiment of the present invention, the formula for the scattering preference score is expressed as: ;in, Indicates candidate continuous band Scattering optimization score; Indicates candidate continuous band Spectral smoothness; This represents the maximum value of spectral smoothness among all candidate continuous bands; Indicates candidate continuous band The average absorbance stability across all wavelengths is the absorption stability level.

[0039] It should be noted that the greater the relative smoothness of the spectral smoothness of the candidate continuous band, the greater the relative smoothness, the more the absorbance characteristics of the wavelengths within the candidate continuous band match the scattering effect, the greater the absorbance stability level, the more it tends to have smooth band characteristics without obvious peaks and valleys, and the higher the scattering optimization score.

[0040] The scattering optimization score quantifies the anti-interference ability and curve smoothness of the band, reflecting the suitability of the candidate continuous band as a pure scattering reference. The higher the scattering optimization score, the smaller the absorption peak interference and the greater the curve smoothness, which is more helpful for subsequent scattering reference.

[0041] The candidate continuous band with the highest scattering optimization score among all candidate continuous bands is selected as the reference scattering band.

[0042] Based on this, the absorbance with the highest scattering score is selected, which best matches the scattering effect. Furthermore, the greater the smoothness feature, the more helpful it is to analyze the impact caused by pure scattering.

[0043] Step S3: For any concentration, based on the detection spectrum at each moment and the absorbance distribution of different wavelengths in the reference scattering band, obtain the initial corrected absorbance of each wavelength at each moment; based on the initial corrected absorbance distribution of each wavelength at different temperatures, obtain the temperature correction coefficient of each wavelength; based on the initial corrected absorbance of each wavelength, the temperature correction coefficient, and the difference between the real-time temperature and the preset reference temperature, obtain the final corrected absorbance of each wavelength at each concentration.

[0044] The reference scattering band is a smooth band without obvious peaks and valleys, and theoretically only contains scattering contributions. The absorbance decreases monotonically with wavelength. Therefore, the absorbance of wavelengths within the reference scattering band is analyzed to reflect the spectral data of scattering contributions. Combined with the absorbance of wavelengths under the detection spectrum, the absorbance of each wavelength is initially corrected. For any concentration, the initial corrected absorbance of each wavelength at each moment is obtained based on the detection spectrum at each moment and the absorbance distribution of different wavelengths in the reference scattering band.

[0045] Preferably, in one embodiment of the present invention, the method for obtaining the initial calibrated absorbance includes: Obtain the scattering curve function fitted by the absorbance of different wavelengths in the reference scattering band; It should be noted that the reference scattering band reflects only the scattering contribution and varies monotonically and smoothly with wavelength, which helps to fundamentally prevent the true characteristic absorption of the components from being misjudged and mixed into the scattering baseline. In the embodiments of the present invention, based on the light scattering theory, the scattering intensity monotonically decreases with increasing wavelength, so a polynomial of the reciprocal of the wavelength can be used for approximation. The scattering model is constructed using the reciprocal of the wavelength polynomial, and the formula is expressed as: ;in, Indicates wavelength absorbance; Represents the model intercept; , Represents the model coefficients.

[0046] The scattering model is fitted by substituting the absorbance at different wavelengths within the reference scattering band. The optimization objective is to minimize the sum of squared residuals between the fitted model value and the absorbance in the reference scattering band. The non-negative model coefficients of the polynomial are solved to obtain the scattering curve function that monotonically decreases with wavelength.

[0047] It should be noted that, in the embodiments of the present invention, the non-negative least squares method is used to solve the fitting polynomial. Since the physical mechanism of scattering determines that its wavelength dependence is continuous and monotonic across the entire wavelength band, the scattering curve function can be applied to any wavelength to obtain the absorbance of each wavelength caused by scattering. The specific non-negative least squares method is a well-known technique to those skilled in the art and will not be described in detail here.

[0048] The absorbance difference between the detection spectrum and the scattering curve function at each time step is obtained for each wavelength. If the absorbance difference is greater than or equal to a preset difference threshold, the absorbance difference is used as the initial corrected absorbance for the corresponding wavelength. If the absorbance difference is less than the preset difference threshold, the initial corrected absorbance for the corresponding wavelength is set to 0.

[0049] It should be noted that the detection spectrum obtained at any concentration under any temperature condition is analyzed to obtain the initial corrected absorbance of each wavelength after removing the scattering effect under the corresponding conditions.

[0050] It should be noted that, considering that absorbance represents the degree to which a substance absorbs light, and theoretically absorbance is greater than or equal to 0, in the embodiments of the present invention, the preset difference threshold is set to 0 to ensure that the spectral data input to the quantitative model conforms to physical common sense and improves the robustness of the system.

[0051] Even considering only the redundant contribution of the fitted scattering baseline to the original spectrum, the obtained corrected absorbance is still affected by temperature, leading to changes in the absorbance coefficient of the absorption peak. Since the absorption peaks of each component in the electroplating solution respond regularly to temperature, analyzing different temperatures at the same concentration reveals that the initial corrected absorbance reflects the pure absorption spectral characteristics after eliminating physical scattering interference, which helps to quantify the regularity of absorbance changes with temperature at each wavelength. Based on the initial corrected absorbance distribution of each wavelength at different temperatures, the temperature correction coefficient for each wavelength is obtained.

[0052] Preferably, in one embodiment of the present invention, the method for obtaining the temperature correction coefficient includes: For any wavelength, the initial corrected absorbance of each concentration at different temperatures at corresponding times is fitted with a straight line, and the slope of the fitted line is used as the temperature correction coefficient for each wavelength.

[0053] It should be noted that, in the embodiments of the present invention, for each wavelength, the collected different temperature points are used as the X-axis, and the initial corrected absorbance at the corresponding temperature time is used as the Y-axis. A straight line is obtained by performing univariate linear fitting. The slope of the straight line is the temperature correction coefficient, which indicates how much the absorbance at the wavelength will drift for every 1°C change in temperature. The fitting can be performed by least squares method or polynomial fitting. The specific means are well known to those skilled in the art and will not be described in detail here.

[0054] The temperature correction factor reflects the rate of absorbance change with temperature; the greater the difference between the real-time temperature and the preset reference temperature, the greater the effect of temperature on the change in absorbance. Based on the temperature correction factor and the difference, it is helpful to quantify the amount of absorbance change under the influence of temperature. The initial corrected absorbance reflects the absorbance after removing scattering features, and further, the effect of temperature removal on the absorbance of the absorption peak is obtained. Based on the initial corrected absorbance of each wavelength, the temperature correction factor, and the difference between the real-time temperature and the preset reference temperature, the final corrected absorbance of each wavelength is obtained.

[0055] Preferably, in one embodiment of the present invention, the method for obtaining the final corrected absorbance includes: For any concentration, obtain the temperature difference between the real-time temperature and the preset reference temperature, obtain the product of the temperature correction coefficient and the temperature difference for each wavelength, calculate the difference between the initial corrected absorbance and the product result for each wavelength, and use it as the final corrected absorbance for each wavelength at the corresponding concentration.

[0056] In one embodiment of the present invention, the formula for the final corrected absorbance for any concentration is expressed as: ;in, Indicates wavelength The final corrected absorbance; Indicates wavelength The initial corrected absorbance; Indicates wavelength Temperature correction factor; This indicates the temperature difference between the real-time temperature and the preset reference temperature.

[0057] It should be noted that the temperature correction coefficient, combined with the difference between the real-time temperature and the reference temperature, reflects the amount of absorbance that needs to be compensated for under the influence of temperature. The larger the difference, the greater the real-time temperature is relative to the reference temperature, and the more necessary it is to remove the influence of temperature on the absorption peak. The smaller the difference, the smaller the real-time temperature is relative to the reference temperature, and the more necessary it is to compensate for the influence of temperature on the absorption peak.

[0058] It should be noted that, in one embodiment of the present invention, the preset reference temperature is the standard reference temperature uniformly used when establishing a quantitative analysis model, and the calibration temperature in the laboratory is usually set to 25°C; in other embodiments of the present invention, the size of the preset reference temperature threshold can be set according to specific circumstances, and will not be limited or elaborated here.

[0059] Step S4: Construct an electroplating solution composition detection model based on the final corrected absorbance at different wavelengths under different concentrations.

[0060] The final calibrated absorbance has eliminated the effects of scattering and temperature fluctuations caused by physical interference such as bubbles and particles, and reflects the pure absorption spectrum at the reference temperature, which is helpful for the detection of component concentration.

[0061] It should be noted that, in another embodiment of the present invention, the composition of the electroplating solution is detected based on the obtained final corrected absorbance: a multivariate calibration method in chemometrics is adopted, using the calibration spectrum composed of the final corrected absorbance after scattering correction and temperature compensation at a known concentration as the feature input, and the known concentration value as the target output, to train and generate a quantitative analysis model, namely the electroplating solution composition detection model. The calibration spectrum composed of the final corrected absorbance of the electroplating solution to be tested is input into the model for analysis, and the real-time concentration values ​​of each metal ion, additive and impurity in the electroplating solution are output.

[0062] It should be noted that, in the embodiments of the present invention, multivariate correction can be performed by methods such as partial least squares regression (PLS) or principal component regression. The specific means are well known to those skilled in the art and will not be described in detail here.

[0063] It should be noted that the scattering characteristics of the electroplating solution may change slowly as production progresses. Therefore, the scattering model needs to be updated adaptively and periodically. By using the new data obtained from each measurement, the model parameters can be continuously optimized to improve long-term accuracy.

[0064] In summary, this invention obtains candidate continuous wavelength bands; based on the absorbance distribution corresponding to different wavelengths in each candidate continuous wavelength band, and the absorbance stability distribution of different wavelengths, a reference scattering wavelength band is selected; for any concentration, based on the detection spectrum at each moment and the absorbance distribution of different wavelengths in the reference scattering wavelength band, the initial corrected absorbance of each wavelength at each moment is obtained; based on the initial corrected absorbance distribution of each wavelength at different temperatures at each moment, the temperature correction coefficient of each wavelength is obtained; combined with the difference between the real-time temperature and the preset reference temperature, the final corrected absorbance of each wavelength at each concentration is obtained, and the composition of the electroplating solution is detected. This invention improves the accuracy of component detection in electroplating solutions by accurately obtaining the final corrected absorbance after removing scattering and temperature fluctuations.

[0065] The present invention also proposes an electroplating solution composition detection system based on spectral technology, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the steps of an electroplating solution composition detection method based on spectral technology.

[0066] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0067] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for detecting the composition of electroplating solution based on spectroscopic technology, characterized in that, The method includes: The detection spectra and temperature data of the electroplating solution at different concentrations were obtained in sequence over time. The spectra included absorbance corresponding to different wavelengths. For any given time, the absorbance stability of each wavelength is obtained based on the absorbance distribution at all concentrations; candidate continuous bands are obtained outside the wavelength range of the characteristic absorption peaks in the detection spectrum; the spectral smoothness of each candidate continuous band is obtained based on the absorbance distribution corresponding to different wavelengths in each candidate continuous band; and reference scattering bands are selected based on the spectral smoothness of each candidate continuous band and the absorbance stability distribution at different wavelengths. For any concentration, the initial corrected absorbance of each wavelength at each moment is obtained based on the detection spectrum at each moment and the absorbance distribution of different wavelengths in the reference scattering band; the temperature correction coefficient of each wavelength is obtained based on the initial corrected absorbance distribution of each wavelength at different temperatures; and the final corrected absorbance of each wavelength at each concentration is obtained based on the initial corrected absorbance of each wavelength, the temperature correction coefficient, and the difference between the real-time temperature and the preset reference temperature. Based on the final corrected absorbance at different wavelengths under different concentrations, a model for detecting the composition of electroplating solutions was constructed.

2. The method for detecting the composition of electroplating solution based on spectroscopic technology according to claim 1, characterized in that, The method for obtaining absorbance stability includes: For any given time, the absorbance fluctuation characteristics at each wavelength under all concentrations are obtained and negatively correlated, which is then used as the first stability coefficient. The value of each wavelength is divided by the value of the maximum wavelength, and this is used as the second stability coefficient. The product of the first stability coefficient and the second stability coefficient is obtained and normalized to obtain the absorbance stability for each wavelength.

3. The method for detecting the composition of electroplating solution based on spectral technology according to claim 1, characterized in that, The method for obtaining the candidate continuous bands includes: Continuous bands outside the wavelength range of the characteristic absorption peak in the detection spectrum are considered as candidate continuous bands.

4. The method for detecting the composition of electroplating solution based on spectroscopic technology according to claim 1, characterized in that, The method for obtaining spectral smoothness includes: Obtain the sequence of absorbance for all wavelengths within the candidate continuous band, and obtain the second-order difference sequence of the sequence. The mean of the squares of the elements in the second-order difference sequence is obtained and negative correlation mapping is performed as the spectral smoothness of each candidate continuous band.

5. The method for detecting the composition of electroplating solution based on spectroscopic technology according to claim 1, characterized in that, The method for obtaining the reference scattering band includes: Based on the spectral smoothness of each candidate continuous band and the stable distribution of absorbance at different wavelengths, the scattering optimization score of each candidate continuous band is obtained. The candidate continuous band with the highest scattering optimization score among all candidate continuous bands is selected as the reference scattering band.

6. The method for detecting the composition of electroplating solution based on spectral technology according to claim 5, characterized in that, The method for obtaining the scattering preference score includes: The maximum value of spectral smoothness among all candidate continuous bands is obtained, and the ratio of the spectral smoothness of each candidate continuous band to the maximum value of spectral smoothness is obtained as the relative smoothness. The mean value of absorbance stability for all wavelengths within each candidate continuous band is obtained as the absorption stability level. The product of relative smoothness and absorption stability level is obtained as the scattering optimization score for each candidate continuous band.

7. The method for detecting the composition of electroplating solution based on spectroscopic technology according to claim 1, characterized in that, The method for obtaining the initial corrected absorbance includes: Obtain the scattering curve function fitted by the absorbance of different wavelengths in the reference scattering band; The absorbance difference at each wavelength between the detection spectrum and the scattering curve function at each time step is obtained as the initial corrected absorbance for each wavelength.

8. The method for detecting the composition of electroplating solution based on spectroscopic technology according to claim 1, characterized in that, The method for obtaining the temperature correction coefficient includes: For any wavelength, the initial corrected absorbance of each concentration at different temperatures at corresponding times is fitted with a straight line, and the slope of the fitted line is used as the temperature correction coefficient for each wavelength.

9. The method for detecting the composition of electroplating solution based on spectroscopic technology according to claim 1, characterized in that, The method for obtaining the final corrected absorbance includes: For any concentration, obtain the temperature difference between the real-time temperature and the preset reference temperature, obtain the product of the temperature correction coefficient and the temperature difference for each wavelength, calculate the difference between the initial corrected absorbance and the product result for each wavelength, and use it as the final corrected absorbance for each wavelength at the corresponding concentration.

10. A system for detecting the composition of an electroplating solution based on spectral technology, the system comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the electroplating solution composition detection method based on spectral technology as described in any one of claims 1 to 9.

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