A method for detecting palladium-silver-copper alloys

Abstract

This invention relates to the field of electrochemical analysis technology of materials, and discloses a method for detecting palladium-silver-copper alloys. The method includes: connecting a palladium-silver-copper alloy working electrode to an electrolyte circuit; pre-enriching the metal components through a cathode constant potential; applying an orthogonal alternating magnetic field during anode differential pulse scanning; physically modulating the interface diffusion layer using the Lorentz force; obtaining a transient distortion current driven by magnetohydrodynamic effects; mapping the current signal to a magnetohydrodynamic inversion model; and extracting independent characteristic quantities characterizing the dissolution properties of each component. This invention achieves baseline purification by deeply coupling physical field modulation and information domain inversion, utilizing the differential effects of magnetic fields on ion mass transfer and neutral hydrogen molecule desorption, and solving the signal overlap and hydrogen evolution interference problems caused by the close potentials of silver and copper, thus ensuring the qualitative and quantitative analysis of trace components in a strong interference system.

Description

Technical Field

[0001] This invention belongs to the field of materials electrochemical analysis technology, and particularly relates to a method for detecting palladium-silver-copper alloys. Background Technology

[0002] The accuracy of the current palladium-silver-copper alloy composition ratio is crucial to the wettability of the solder and the arc erosion resistance of electrical contact components. Analyzing material composition by measuring its electrochemical properties is a widely accepted approach in the industry. Among these methods, anodic stripping voltammetry uses controlled potential scanning to oxidize and dissolve metal atoms enriched on the working electrode surface, achieving quantitative analysis based on the response current peak. However, the palladium-silver-copper ternary system exhibits highly challenging physicochemical characteristics. Because the standard redox potentials of silver and copper ions are close, their anodic stripping currents experience severe physical broadening and signal overlap along the scanning time axis, posing a fundamental resolution limitation to conventional electrochemical detection methods. Besides hardware limitations, there are also shortcomings in the overlapping peak signal processing algorithm. For example, Chinese invention patent application CN117291831A discloses an overlapping peak curve separation method and a metal ion determination method. It uses a sharpening algorithm combined with a snake optimization algorithm to mathematically fit and separate overlapping voltammetric peaks. In the palladium-silver-copper strong interference multi-perturbation system, the pure mathematical fitting method is limited by the preset idealized Gaussian model and is difficult to penetrate the nonlinear background noise caused by the hydrogen evolution reaction of palladium. Due to the lack of physical field assistance to distinguish the underlying support, the algorithm's accuracy in identifying highly overlapping potential groups is easily trapped in local optima due to the influence of initial parameters, causing uncontrollable deviations in the quantitative results of complex alloy matrices.

[0003] To improve the resolution of multi-component identification, conventional techniques attempt to add chemical complexing agents to the electrolyte system to widen the response peak spacing by utilizing potential shift. This approach alters the original chemical state of the test object, and the complex chemical pretreatment process easily introduces external impurities, making it difficult to meet the engineering requirements of in-situ non-destructive testing. If physical field modulation methods are used, such as introducing a high-frequency alternating magnetic field to generate magnetohydrodynamic effects, new physical constraints are encountered. The alternating magnetic field generates an induced current inside the alloy probe, and the resulting Joule heating effect causes temperature difference convection in the micro-region. This thermal gradient effect disrupts the stability of the ion mass transfer boundary layer induced by magnetohydrodynamics, causing nonlinear distortion in the extracted current signal. At the same time, palladium has obvious hydrogen adsorption characteristics, generating complex hydrogen desorption current during the anodic dissolution stage, causing nonlinear distortion of the background baseline and drowning out the effective signal.

[0004] Therefore, the technical problem to be solved by this invention is how to achieve physical separation of silver-copper overlapping dissolution signals without introducing chemical complexing agents, and to eliminate the interference of palladium matrix and magnetocaloric effect on detection accuracy. Summary of the Invention

[0005] In this technical solution, a method for detecting palladium-silver-copper alloys includes the following steps: Step 101: Place the palladium-silver-copper alloy working electrode, reference electrode, and auxiliary electrode with a preset exposure area in a micro electrochemical cell containing electrolyte to form an electrochemical measurement circuit. Step 102: Apply a cathode constant potential to the working electrode and form a metal enrichment layer on the surface of the working electrode within a preset enrichment time. Step 103: Perform anode differential pulse potential scanning. During the scanning, a periodic orthogonal alternating magnetic field with magnetic induction intensity varying with the scanning potential is applied to the surface region of the working electrode. The Lorentz force is used to guide the mass transfer path of silver ions and copper ions in a spatial asymmetric manner, generating a dynamic response current that characterizes the mass transfer properties of the diffusion layer. The waveform distortion characteristics of the dynamic response current modulated by the orthogonal alternating magnetic field are recorded. Step 104: The dynamic response current and its waveform distortion characteristics are mapped into the magnetohydrodynamic inversion model. Based on the differential modulation law of the mass transfer resistance of silver ions and copper ions by the orthogonal alternating magnetic field, the dynamic response current is deconvolved in the information domain to extract independent feature vectors characterizing the dissolution characteristics of each component. The ion activity weight coefficients in the magnetohydrodynamic inversion model are iteratively optimized using the least squares method until the residual between the model calculated current and the measured response current converges to the preset range. Finally, the quantitative content of palladium, silver and copper components in the palladium-silver-copper alloy is determined.

[0006] Preferably, step 104 further includes a baseline purification step based on the difference in magnetic field response: extracting the steady-state component of the orthogonal alternating magnetic field at the zero point of magnetic induction intensity, identifying the background leakage current generated by the catalytic hydrogen evolution of palladium at the working electrode interface; using the background leakage current as a calibration benchmark, zero-point correction is performed on the dynamic response current to eliminate the influence of the hydrogen evolution reaction on the baseline of the dissolution peaks of silver and copper elements, thereby improving the identification accuracy of the magnetohydrodynamic inversion model for overlapping current peaks.

[0007] Preferably, the magnetic induction intensity of the orthogonal alternating magnetic field in step 103 is 0.1T to 1.5T, and the frequency of the orthogonal alternating magnetic field is synchronized with the sampling frequency of the anode differential pulse potential scan to ensure that each sampling point covers the complete magnetic field change cycle.

[0008] Preferably, the electrolyte in the micro electrochemical cell is a perchloric acid solution with a concentration of 0.1 mol / L to 0.5 mol / L, and no chemical complexing reagents are added to the electrolyte. Component separation is achieved through physical intervention of an orthogonal alternating magnetic field.

[0009] Preferably, in step 102, the cathode constant potential is -0.4V to -0.2V, and the preset enrichment time is 30s to 120s, so as to control the thickness of the metal enrichment layer to be between 10nm and 100nm.

[0010] Preferably, in step 103, the starting potential of the anode differential pulse potential scan is -0.2V, the ending potential is 0.6V, and the scan speed is 10mV / s to 50mV / s.

[0011] Preferably, the magnetohydrodynamic inversion model establishes nonlinear constraint rules describing the change of ion mass transfer flux with potential under the Lorentz force field by coupling the Navier-Stokes equations and the Nernst-Planck equations.

[0012] Preferably, the preset exposure area of ​​the working electrode is limited to 0.5 mm by a laser precision ablation process. 2 Up to 2.0mm 2 This is to maintain the stability of the diffusion layer under magnetic field modulation.

[0013] Preferably, after determining the quantitative content, the sum of the mass percentages of each component is calculated, and the reliability of the test is evaluated based on the deviation of the sum of the mass percentages from 100%, and a composition analysis report of the palladium-silver-copper alloy is output.

[0014] Compared with existing technologies, the detection method for palladium-silver-copper alloys of the present invention has the following advantages: 1. In the detection of palladium-silver-copper alloys, the phase synchronization mechanism between the intermittent burst-type alternating magnetic field and the step cycle of the anodic differential pulse voltage utilizes the hysteresis characteristic of heat conduction to establish a stable mass transfer boundary layer induced by magnetohydrodynamics inside the electrolyte. At the same time, the dissipation of Joule heat inside the alloy electrode is completed during the voltage pulse interval. This timing control logic ensures that the current acquisition action is completed within the physical window when the fluid boundary layer induced by Lorentz force is stably established and the internal temperature difference convection of the electrode has not yet occurred. This avoids the distortion of the ion mass transfer law due to the parasitic heat effect generated by the high-frequency magnetic field, and improves the environmental anti-interference capability and signal repeatability during the measurement process.

[0015] 2. Based on the topology optimization and mapping logic of the CAD feature library, the nonlinear transient dissolution current sequence modulated by the physical field is converted into a target state vector composed of time domain and amplitude characteristics. Iterative correction is performed by calling the preset magnetohydrodynamic virtual diffusion layer geometric topology model. The convergence of the simulation response and the measured signal is evaluated by the fitness function. The complex cross-physical field interference phenomenon is transformed into model parameter inversion in the information domain. This breaks the dependence of traditional linear analytical methods on the physical resolution of sensor hardware and realizes the decoupling and restoration of the overlapping characteristic peaks of the component to be measured.

[0016] 3. Background baseline adaptive correction method: This method utilizes the difference between the sensitivity of magnetic field to charged ion mass transfer and passivation of neutral hydrogen molecule desorption. By extracting the residual static current during the magnetic field off-peak period, it identifies the background current of pure hydrogen desorption dominated by palladium. This mechanism eliminates the baseline nonlinear distortion caused by palladium-catalyzed hydrogen evolution without adding external chemical complexing reagents, and purifies the characteristic peaks of silver-copper separation. Thus, it achieves accurate analysis of multi-component coexistence systems while maintaining the original state of the alloy. Attached Figure Description

[0017] Figure 1 This is a flowchart of the electrochemical detection steps for palladium-silver-copper alloy modulated by magnetic field according to the present invention; Figure 2 This is a schematic diagram of the pretreatment and multi-branch component determination process for palladium-silver-copper alloy samples according to the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0019] It should be noted that all directional and positional terms used in this invention, such as: up, down, left, right, front, back, vertical, horizontal, inner, outer, top, bottom, transverse, longitudinal, center, etc., are only used to explain the relative positional relationship and connection between components in a specific state (as shown in the accompanying drawings). They are only for the convenience of describing this invention and do not require that this invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. In addition, the descriptions of "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms installation, connection, and linking should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood in conjunction with the specific circumstances.

[0021] In the description of this specification, references to the terms "an embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0022] A method for detecting palladium-silver-copper alloys includes the following steps: Step 101: Place the palladium-silver-copper alloy working electrode, reference electrode, and auxiliary electrode with a preset exposure area in a micro electrochemical cell containing electrolyte to form an electrochemical measurement circuit. Step 102: Apply a cathode constant potential to the working electrode and form a metal enrichment layer on the surface of the working electrode within a preset enrichment time. Step 103: Perform anode differential pulse potential scanning. During the scanning, a periodic orthogonal alternating magnetic field with magnetic induction intensity varying with the scanning potential is applied to the surface region of the working electrode. The Lorentz force is used to guide the mass transfer path of silver ions and copper ions in a spatial asymmetric manner, generating a dynamic response current that characterizes the mass transfer properties of the diffusion layer. The waveform distortion characteristics of the dynamic response current modulated by the orthogonal alternating magnetic field are recorded. Step 104: The dynamic response current and its waveform distortion characteristics are mapped into the magnetohydrodynamic inversion model. Based on the differential modulation law of the mass transfer resistance of silver ions and copper ions by the orthogonal alternating magnetic field, the dynamic response current is deconvolved in the information domain to extract independent feature vectors characterizing the dissolution characteristics of each component. The ion activity weight coefficients in the magnetohydrodynamic inversion model are iteratively optimized using the least squares method until the residual between the model calculated current and the measured response current converges to the preset range. Finally, the quantitative content of palladium, silver and copper components in the palladium-silver-copper alloy is determined.

[0023] Preferably, step 104 further includes a baseline purification step based on the difference in magnetic field response: extracting the steady-state component of the orthogonal alternating magnetic field at the zero point of magnetic induction intensity, identifying the background leakage current generated by the catalytic hydrogen evolution of palladium at the working electrode interface; using the background leakage current as a calibration benchmark, zero-point correction is performed on the dynamic response current to eliminate the influence of the hydrogen evolution reaction on the baseline of the dissolution peaks of silver and copper elements, thereby improving the identification accuracy of the magnetohydrodynamic inversion model for overlapping current peaks.

[0024] Preferably, the magnetic induction intensity of the orthogonal alternating magnetic field in step 103 is 0.1T to 1.5T, and the frequency of the orthogonal alternating magnetic field is synchronized with the sampling frequency of the anode differential pulse potential scan to ensure that each sampling point covers the complete magnetic field change cycle.

[0025] Preferably, the electrolyte in the micro electrochemical cell is a perchloric acid solution with a concentration of 0.1 mol / L to 0.5 mol / L, and no chemical complexing reagents are added to the electrolyte. Component separation is achieved through physical intervention of an orthogonal alternating magnetic field.

[0026] Preferably, in step 102, the cathode constant potential is -0.4V to -0.2V, and the preset enrichment time is 30s to 120s, so as to control the thickness of the metal enrichment layer to be between 10nm and 100nm.

[0027] Preferably, in step 104, the fitness function F is used to evaluate the convergence of the residuals. The expression for the fitness function is: ,in, This represents the characteristic vector of the measured dynamic response current. The simulated response feature vector generated by the magnetohydrodynamic inversion model. This is a preset range normalization weighting factor.

[0028] Preferably, in step 103, the starting potential of the anode differential pulse potential scan is -0.2V, the ending potential is 0.6V, and the scan speed is 10mV / s to 50mV / s.

[0029] Preferably, the magnetohydrodynamic inversion model establishes nonlinear constraint rules describing the change of ion mass transfer flux with potential under the Lorentz force field by coupling the Navier-Stokes equations and the Nernst-Planck equations.

[0030] Preferably, the preset exposure area of ​​the working electrode is limited to 0.5 mm by a laser precision ablation process. 2 Up to 2.0mm 2 This is to maintain the stability of the diffusion layer under magnetic field modulation.

[0031] Preferably, after determining the quantitative content, the sum of the mass percentages of each component is calculated, and the reliability of the test is evaluated based on the deviation of the sum of the mass percentages from 100%, and a composition analysis report of the palladium-silver-copper alloy is output.

[0032] Example 1: In the quality control of high-frequency electrical contact components in a semiconductor packaging production line, the standard redox potential difference between silver and copper ions in the target palladium-silver-copper ternary alloy is less than 150mV. This causes physical broadening and signal overlap of the characteristic current peaks of both ions on the time axis during anodic stripping voltammetry testing. Furthermore, the palladium element in the alloy matrix exhibits hydrogen adsorption characteristics during the cathodic polarization stage, resulting in nonlinear distortion of the subsequent stripping baseline and masking the true characteristic signal, thus exposing an area of ​​0.5mm². 2 Up to 2.0mm 2A palladium-silver-copper alloy working electrode, reference electrode, and auxiliary electrode are placed in a micro-electrochemical cell containing an electrolyte to form an electrochemical measurement circuit. The electrolyte is a perchloric acid solution with a concentration of 0.1 mol / L to 0.5 mol / L. A cathode constant potential of -0.4 V to -0.2 V is applied to the working electrode. During a preset enrichment time of 30 s to 120 s, a metal enrichment layer with a thickness of 10 nm to 100 nm is formed on the surface of the working electrode. For the alloy directly used as the working electrode measurement system, the perchloric acid solution in the micro-electrochemical cell undergoes a localized interfacial micro-dissolution reaction with the alloy surface in the initial stage of electrode immersion. A high-concentration metal ion diffusion layer accumulates in the liquid phase space of 5 μm to 10 μm from the electrode surface. In step 102, a negative cathode constant potential is applied to drive the silver ions and copper ions in the diffusion layer to undergo reverse electrochemical reduction and be deposited in situ on the surface of the palladium alloy substrate. The cathode polarization process reconstructs the original rough alloy machined surface into a micro-scale. A dense, uniformly oriented, zero-valence metal enrichment layer eliminates the physical interference of residual stress from initial substrate processing and natural oxide film on the subsequent diffusion boundary layer hydrodynamic morphology. A unified initial boundary condition for anodic dissolution is established, and an anodic differential pulse potential scan with an initial potential of -0.2V and a termination potential of 0.6V is initiated. During the scan, a periodic orthogonal alternating magnetic field is synchronously applied to the working electrode surface region. The frequency of this alternating magnetic field is synchronized with the sampling frequency of the anodic differential pulse potential scan, and the magnetic induction intensity ranges from 0.1T to 1.5T. The alternating Lorentz force generated by the alternating magnetic field exerts spatial asymmetric guidance on the mass transfer paths of silver and copper ions. Based on the differences in the hydrated ionic radius and effective charge-to-mass ratio of silver and copper ions, magnetohydrodynamic effects selectively compress the diffusion layer thickness of different ions, separating overlapping dissolution paths in physical space and generating a dynamic response current characterizing the mass transfer properties of the diffusion layer.

[0033] The steady-state component of the orthogonal alternating magnetic field at the zero point of magnetic induction intensity was extracted. The background leakage current generated by palladium catalyzing hydrogen evolution at the working electrode interface was identified. The background leakage current was used as a calibration benchmark to correct the dynamic response current. The elevation components of the dissolution peaks of silver and copper elements due to the hydrogen evolution reaction were filtered out. The waveform distortion characteristics of the dynamic response current modulated by the orthogonal alternating magnetic field were recorded. These waveform distortion characteristics were input into a preset magnetohydrodynamic inversion model. The magnetohydrodynamic inversion model was coupled with the Navier-Stokes equation and the Nernst-Planck equation to establish a nonlinear constraint rule describing the change of ion mass transfer flux with potential under the Lorentz force field. The fitness function was calculated to evaluate the convergence of the residuals. The formula for calculating the fitness function is as follows: Where F is the fitness function, This represents the characteristic vector of the measured dynamic response current. The simulated response feature vector generated by the magnetohydrodynamic inversion model. This is a preset range normalization weighting factor.

[0034] The nonlinear waveform distortion induced by the physical magnetic field provides an input vector containing differences in the diffusion layer morphology for the magnetohydrodynamic (MHD) inversion model. Within the information domain, the model extracts independent feature vectors characterizing the dissolution properties of each component through deconvolution operations. The ion activity weighting coefficients in the MHD inversion model are iteratively optimized using the least squares method. When the fitness function F is less than a preset threshold, the residual between the calculated current and the measured response current is determined to have converged to a preset range. The current calculation model parameters are then locked, and the quantitative content data of palladium, silver, and copper elements determined under this convergence state are extracted. The mass percentage of each element is then calculated. The system outputs reliability assessment parameters based on the deviation of the sum of mass percentages from 100%, generating a composition analysis report for the palladium-silver-copper alloy. For the continuous mass transfer interference caused by the high similarity of oxidation potentials between silver and copper elements during the anodic differential pulse potential scan, the test system initiates a dynamic synchronous modulation procedure where the magnetic induction intensity continuously changes with the scanning potential. The control unit acquires the scanning potential voltage value output by the potentiostat in real time, converts it into a digital variable, and inputs it into the field strength mapping register. This field strength mapping register is programmed with a nonlinear magnetic field driving matrix adapted to the difference in the effective charge-to-mass ratio of silver and copper ions. As the scanning potential voltage value falls... When silver and copper elements enter the co-dissolution interference potential range, the control unit increases the excitation current of the three-dimensional Helmholtz coil according to the nonlinear magnetic field driving matrix. The peak Lorentz force generated by the exponentially increasing alternating magnetic field applies spatial asymmetric compression to the overlapping ion diffusion trajectories. When the scanning potential voltage deviates from the co-dissolution interference potential range, the system controls the excitation current to decrease linearly at a preset negative slope, suppressing the thermal convection turbulence dissipation induced by the continuous high-intensity magnetic field at the working electrode interface. This dynamic coupling mechanism between the potential voltage and the alternating magnetic field aligns the change in mass transfer resistance behavior of specific ions with specific physical oxidation moments, enabling inversion of the model in the subsequent information domain. The output exhibits a dynamic response current waveform distortion characteristic with a deterministic evolution law. The specific timing control parameters are as follows: the pulse width of the anode differential pulse is set to 50 milliseconds; the magnetic field drive signal is started 5 milliseconds after the pulse rising edge is triggered; sampling stops and the magnetic field is turned off at 45 milliseconds; a 5-millisecond interval is reserved to eliminate the 0.2-degree Celsius Joule thermal disturbance induced by the 1.5 Tesla magnetic field on the 0.5 square millimeter electrode; the system acquisition counter performs a phase comparison between the magnetic field and the potential every 10 clock pulses to ensure that the synchronization deviation of the sampling window is less than 10 microseconds, thereby ensuring that the Lorentz force corresponding to each sampling point is constant.

[0035] Example 2: When the system faces technical conditions such as overlapping electrochemical dissolution signals of silver and copper and baseline nonlinear distortion caused by hydrogen evolution of palladium in a semiconductor manufacturing environment, the test platform is equipped with a potentiostat system including a micro-electrochemical cell. The current sampling resolution of this potentiostat system is set to nanoampere level and the sampling rate is greater than 1 kHz. It is equipped with spatially orthogonal three-dimensional Helmholtz coils. Gaussian white noise with a signal-to-noise ratio of 20 dB is injected into the measuring electrode circuit and superimposed with 50 Hz power frequency harmonic disturbance to balance the asymmetric compression effect of Lorentz force on the mass transfer path and the interference of double-layer interface thermal convection caused by high-frequency and high-intensity magnetic field. According to the ion evolution law of Nernst-Planck equation, when the effective charge-to-mass ratio difference of the analyte ions is within a preset range... Within a time limit, increasing the magnetic induction intensity increases the ion orbital offset. If the magnetic induction intensity crosses a specific threshold, the resulting thermal convection vortex disrupts the static diffusion layer boundary on the electrode surface. 0.8T is selected as the preferred alternating magnetic field strength parameter to verify this balance relationship. A standard target with a fixed palladium-silver-copper mass ratio is prepared as a test sample. A control group is constructed without applying an alternating magnetic field and with the baseline purification algorithm turned off. Measured electrochemical current data show that within the target voltage range, the oxidation peaks of silver and copper elements merge to form a single broad envelope feature. The peak resolution is lower than the minimum scale of the instrument. Simultaneously, affected by the palladium hydrogen evolution reaction, the dissolution baseline exhibits a positive nonlinear upward slope. Background perturbation reduces the signal-to-noise ratio of the characteristic signal to 8.2dB.

[0036] A complete technical solution was used to construct the experimental group. A 0.1 mol / L perchloric acid solution was selected as the electrolyte. A cathode constant potential of -0.3 V was applied to the working electrode and enriched for 60 s. An alternating magnetic field of 0.8 T was used to accompany the anode differential pulse scan. The steady-state background leakage current at the zero point of magnetic induction intensity was extracted. Based on this steady-state background leakage current, the dynamic response current sequence was corrected. After baseline purification, the distorted signal with Gaussian white noise returned to a flat current baseline, and the signal-to-noise ratio was improved to 35.4 dB. In this process, the value of the regularization parameter Lambda was obtained through the following calibration steps: Within 50 milliseconds before the start of the anode scan, the system performed 100 rapid samples of the background noise at the static potential, and the square root of the noise was calculated. The variance is 1.2 nanoamps, and the Lambda parameter is automatically set to 0.01 times this variance, i.e., 0.012. If the variance exceeds 10.0 nanoamps, Lambda is increased to 0.1 to enhance the smoothing effect. At the same time, the dynamic fitness convergence threshold is set to 0.005 times the range normalization weight factor. That is, when the value of the fitness function F is less than 0.005 for 5 consecutive calculations, the system determines that it has converged and stops iterating. Due to the differential compression of the Lorentz force, two independent feature evolution envelopes are separated from the differential feature vector of the dynamic response current. The cross-interference rate between the silver feature vector and the copper feature vector output by the information domain inversion is less than 1.5%, and the relative error between the output component content and the standard target material ratio is 1.1%.

[0037] Two out-of-range control groups were set with magnetic induction intensities of 0.05T and 2.0T. When the magnetic induction intensity was set to 0.05T, the Lorentz force was insufficient to overcome the Brownian random diffusion of ions, and the overlap area of ​​the dissolution peaks of silver and copper elements in the extracted waveform distortion features reached 68.5%, with no signal separation. When the magnetic induction intensity was increased to 2.0T, the interfacial fluid was disturbed by thermal convection, which destroyed the ordered diffusion layer. The absolute value of the extracted characteristic current decreased by 42.3%, causing irreversible waveform distortion, and the calculation residual of the fitness function F could not converge. The test data of three gradient levels of 0.05T, 0.8T and 2.0T confirmed that the limited range of 0.1T to 1.5T is a good balance between spatial separation and boundary conditions. The effective working window for surface stability was established. A partially missing control group was set with a 0.8T alternating magnetic field applied but the baseline purification algorithm turned off. The data showed that the dissolution peaks of silver and copper elements under this condition physically separated on the time axis, but the unfiltered hydrogen evolution leakage current raised the background baseline, causing the waveform reference point of the input magnetohydrodynamic inversion model to shift, and the quantitative relative error of the output reached 14.3%. The data of the experimental group and the partially missing control group were compared to confirm that the alternating magnetic field spatial modulation and the zero-point baseline purification algorithm formed a synergistic effect mechanism. The magnetic field fluid control within a specific range and the information domain deconvolution operation suppressed the calculation deviation caused by electrochemical similarity and environmental disturbance, and verified the analytical accuracy of ternary alloys under multi-disturbance conditions.

[0038] Example 3: In semiconductor manufacturing environments, electrolyte temperature fluctuations and uneven electrode surface roughness cause dynamic drift of the background noise baseline. Static convergence criteria cannot adapt to environmental evolution. Before starting the anode differential pulse potential scan, the test system performs an endogenous threshold calibration procedure. When no orthogonal alternating magnetic field is applied and the scanning potential is within the hydrogen evolution potential range of palladium, the potentiostat continuously collects a preset number of steady-state leakage current discrete data points. The system calculates the discrete variance sequence based on these steady-state leakage current discrete data points, multiplies its maximum value by the system's preset instrument quantization noise coefficient, and generates a dynamic fitness convergence threshold. This operation transforms the random disturbance level of the physical environment into a deterministic algorithm decision boundary, eliminating the dependence of the decision threshold setting on human experience.

[0039] After threshold calibration, the system initiates an anode differential pulse potential scan with orthogonal alternating magnetic field modulation to acquire the dynamic response current sequence. To extract independent eigenvectors characterizing the dissolution properties of each component, the system constructs a discrete deconvolution operator based on Tikhonov regularization. The system extracts the point spread function of the Navier-Stokes equations and the Nernst-Planck equations under a specific Lorentz force field and discretizes it into the system transfer matrix. A linear discrete equation system is constructed with the independent eigenvectors of each component to be determined as the unknown matrix and the dynamic response current sequence as the observation matrix. For the ill-posed state of the inverse problem of decoupling overlapping signals, the system introduces a regularization constraint term into this linear discrete equation system. The specific deconvolution calculation formula is as follows: ,in, Let be the matrix containing the independent eigenvectors of each component to be determined; H is the system transfer matrix generated by discretizing the point spread function; λ is the transpose of the system transfer matrix; λ is a dimensionless regularization parameter, the value of which is calculated using the generalized cross-validation method based on the discrete variance sequence; I is the identity matrix. The observation matrix is ​​composed of the measured dynamic response current sequence. The unit of this observation matrix is ​​ampere. The system solves the matrix equation with regularization constraint terms and reconstructs the physically independent silver eigenvector and copper eigenvector from the observation matrix containing background noise. This matrix operation mechanism maps the nonlinear waveform distortion caused by the ion diffusion layer compression effect into an independent component signal expression in linear space.

[0040] The system substitutes the obtained silver and copper eigenvectors into the magnetohydrodynamic inversion model to generate simulation response eigenvectors. It uses the dynamic fitness convergence threshold generated by the aforementioned calibration procedure to determine the numerical state of the fitness function F. When the calculated value is lower than the dynamic fitness convergence threshold, the system locks the current calculation model parameters and quantitative content data, calculates the mass percentage and outputs a component analysis report. The discrete deconvolution operator combined with the adaptive physical boundary judgment logic suppresses the interference of environmental dynamic drift on the separation of trace components and maintains analytical determinism under time-varying conditions.

[0041] Example 4: When the system faces the condition of spatial magnetic field distribution distortion caused by the geometric tolerance of the micro-electrochemical cell and the assembly of the three-dimensional Helmholtz coil, the test system initiates an offline spatial mapping calibration procedure to establish the physical correlation of the system transfer matrix H; a single-component silver ion reference electrolyte of known concentration is injected into the micro-electrochemical cell, driving the three-dimensional Helmholtz coil to output an alternating magnetic field with stepwise increasing magnetic induction intensity, and the potentiostat simultaneously starts the anode differential pulse potential scan; the system collects the single-component dynamic response current sequence corresponding to each magnetic field step and extracts the discrete gradient data of the waveform envelope; the system compares the discrete gradient data with the theoretical mass transfer flux differential calculated based on the Nernst-Planck equation, and then... The offset is used to reconstruct the spatial distribution field of the Lorentz force deflection angle on the actual electrode surface. This distribution field is then transformed into basic grid node parameters. During the physical correlation stage of establishing the system transfer matrix H, the three-dimensional geometric data of the internal flow channel and electrode spatial arrangement of the micro-electrochemical cell are read. The working electrode surface is defined as the fluid no-slip boundary. The discrete gradient data is extracted offline and substituted into the source term nodes of the finite element fluid calculation module. The electrolyte dynamic viscosity and density reference parameters are set. The diffusion boundary layer region is divided into three-dimensional computational grids according to a spatial scale of 10 micrometers to 50 micrometers. The finite element fluid calculation module solves the steady Navier-Stokes equations and outputs the micro-region fluid velocity vector distribution field modulated by the alternating Lorentz force volume force.

[0042] The velocity vector distribution field of the micro-region fluid is extracted and input as a convection transport parameter into the Nernst-Planck solver. Ion electromigration and concentration gradient diffusion are solved simultaneously. Ion flux values ​​at core grid nodes from 1 nm to 10 nm from the working electrode surface are collected. The current responsivity of each node at different scanning potentials is extracted into two-dimensional matrix elements according to spatial three-dimensional coordinates and time series. A discrete-point diffusion function set with dimensions matching the number of sampling points of the potentiostat hardware is generated. This discrete-point diffusion function set is constructed using a 50x50 linear mapping weight matrix, and the fluid velocity distribution of the 2500 three-dimensional micro-region grid is analyzed. The velocity vector is accumulated into the one-dimensional current time axis coordinate with a weight ratio of 0.02. The system reads 50 feature sections located 10 to 50 micrometers above the working electrode surface. The ion flux of each section is spatially reduced according to the attenuation ratio of 1.0 divided by the square of the distance based on its radial distance from the electrode center. This converts the dynamic mass transfer flux in three-dimensional space into a 1kHz sampling rate current sequence received by a single-point electrode. The discrete point diffusion function set is then used to construct the system transfer matrix H, which quantifies the mathematical transfer weight of the microscopic physical convection mass transfer to the detected current signal at the sensor interface.

[0043] The system extracts the basic grid node parameters, substitutes them into the Navier-Stokes fluid equations to initiate finite element calculations, generates a discrete point diffusion function set, and assembles the system transfer matrix H specific to the current hardware. The system drains the reference electrolyte and injects a blank perchloric acid solution. With the alternating magnetic field turned off and the scanning potential within the palladium hydrogen evolution range, the system continuously acquires the field-free background current. The root mean square error of this field-free background current is calculated, and a range-normalized weighting factor is generated. The data is written into the control module register; this offline calibration procedure cuts off the interference path of hardware assembly tolerance on the inversion model, so that the dynamic response current is calibrated and mapped as an independent component feature by the system transfer matrix H.

[0044] Example 5: When the system faces the condition of degradation of the working electrode surface morphology and fluctuations in enrichment efficiency caused by the range of concentration of the test solution in continuous batch testing tasks, the test system initiates adaptive state verification and dynamic parameter calibration steps; after the potentiostat is connected to the working electrode, a potassium ferricyanide standard probe solution of a preset concentration is injected, and an AC excitation signal with a frequency in the range of 100kHz to 0.1Hz is output to the working electrode to obtain the interface AC impedance spectrum; the system extracts the charge transfer resistance characteristic value of the AC impedance spectrum in the high-frequency region, calculates the difference between the characteristic value and the clean electrode reference resistance pre-stored in the register, if... If the difference exceeds the system's set tolerance threshold, the control module outputs an electrode reset command to the operation terminal to block the interference path caused by surface passivation on mass transfer kinetics. If the difference is below the tolerance threshold, the system drains the standard probe solution and injects the palladium-silver-copper alloy solution to be tested. A defined cathode constant potential is applied to the working electrode, and the cathode polarization current sequence is collected simultaneously. The system calculates the first derivative of the cathode polarization current sequence over time and tracks the kinetic inflection point where the first derivative decays from a negative extreme to approach zero. This state indicates that the concentration polarization and reduction deposition of alloy ions at the liquid-solid interface have reached mass transfer equilibrium.

[0045] The system extracts the time coordinates corresponding to the dynamic inflection point and calculates the enriched time parameters specific to the current sample. The quantization correlation satisfies the equation. ,in, The enrichment time parameter is output to the control sequence. The time coordinates corresponding to the dynamic inflection point. The system response delay constant is preset; the enrichment time parameter is overwritten into the preset enrichment time register of the differential pulse potential scanning module. This step transforms the physical state evolution of the electrochemical interface into a quantitative test boundary, maintaining the determinism of quantitative analysis of multiple batches of samples.

[0046] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A method for detecting palladium-silver-copper alloys, characterized in that, Includes the following steps: Step 101: Place the palladium-silver-copper alloy working electrode, reference electrode, and auxiliary electrode with a preset exposure area in a micro electrochemical cell containing electrolyte to form an electrochemical measurement circuit. Step 102: Apply a cathode constant potential to the working electrode and form a metal enrichment layer on the surface of the working electrode within a preset enrichment time. Step 103: Perform anode differential pulse potential scanning. During the scanning, a periodic orthogonal alternating magnetic field with magnetic induction intensity varying with the scanning potential is applied to the surface region of the working electrode. The Lorentz force is used to guide the mass transfer path of silver ions and copper ions in a spatial asymmetric manner, generating a dynamic response current that characterizes the mass transfer properties of the diffusion layer. The waveform distortion characteristics of the dynamic response current modulated by the orthogonal alternating magnetic field are recorded. Step 104: The dynamic response current and its waveform distortion characteristics are mapped into the magnetohydrodynamic inversion model. Based on the differential modulation law of the mass transfer resistance of silver ions and copper ions by the orthogonal alternating magnetic field, the dynamic response current is deconvolved in the information domain to extract independent feature vectors characterizing the dissolution characteristics of each component. The ion activity weight coefficients in the magnetohydrodynamic inversion model are iteratively optimized using the least squares method until the residual between the model calculated current and the measured response current converges to the preset range. Finally, the quantitative content of palladium, silver and copper components in the palladium-silver-copper alloy is determined.

2. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, Step 104 also includes a baseline purification step based on the difference in magnetic field response: extracting the steady-state component of the orthogonal alternating magnetic field at the zero point of magnetic induction intensity, and identifying the background leakage current generated by palladium element catalytic hydrogen evolution at the working electrode interface; Using the background leakage current as a calibration benchmark, the dynamic response current is zero-point corrected to eliminate the influence of the hydrogen evolution reaction on the baseline of the dissolution peaks of silver and copper elements, thereby improving the identification accuracy of the magnetohydrodynamic inversion model for overlapping current peaks.

3. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, In step 103, the magnetic induction intensity of the orthogonal alternating magnetic field is 0.1T to 1.5T, and the frequency of the orthogonal alternating magnetic field is synchronized with the sampling frequency of the anode differential pulse potential scan to ensure that each sampling point covers the complete magnetic field change cycle.

4. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, The electrolyte in the micro electrochemical cell is a perchloric acid solution with a concentration of 0.1 mol / L to 0.5 mol / L, and no chemical complexing reagents are added to the electrolyte. Component separation is achieved through physical intervention of an orthogonal alternating magnetic field.

5. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, In step 102, the cathode constant potential is -0.4V to -0.2V, and the preset enrichment time is 30s to 120s, so as to control the thickness of the metal enrichment layer to be between 10nm and 100nm.

6. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, In step 103, the starting potential of the anode differential pulse potential scan is -0.2V, the ending potential is 0.6V, and the scan speed is 10mV / s to 50mV / s.

7. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, The magnetohydrodynamic inversion model establishes nonlinear constraint rules describing the variation of ion mass transfer flux with potential under the Lorentz force field by coupling the Navier-Stokes equations and the Nernst-Planck equations.

8. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, The preset exposed area of the working electrode is defined as 0.5mm by a laser precision stripping process 2 to 2.0mm 2 to maintain the stability of the diffusion layer under magnetic field modulation.

9. The method for detecting palladium-silver-copper alloy according to claim 1, characterized in that, After determining the quantitative content, the sum of the mass percentages of each component is calculated, and the reliability of the test is evaluated based on the deviation of the sum of the mass percentages from 100%, and a composition analysis report of the palladium-silver-copper alloy is output.

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