Copper foil coating content detection method

Abstract

The invention relates to the technical field of new material detection, in particular to a copper foil coating content detection method. The method comprises the following steps: preparing a plurality of mixed standard solutions; the mixed standard solution comprises copper ions and at least one to-be-detected element ion; in the plurality of mixed standard solutions, the copper ion concentrations are the same and are first preset concentration values; measuring a plurality of mixed standard solutions, and establishing a standard curve between a theoretical value and a measured value of the ion concentration of each to-be-measured element; dissolving a plating layer on the surface of the to-be-detected copper foil by using nitric acid, and filtering to obtain a to-be-detected sample solution; adding copper salt into the to-be-detected sample solution to obtain a to-be-detected analysis solution; measuring the to-be-measured analysis solution to obtain the measurement concentration of each to-be-measured element ion; according to the measured concentration of each to-be-measured element ion and the corresponding standard curve, the corrected content of each to-be-measured element ion is obtained. The problem that an existing copper foil coating content detection method is low in detection accuracy is solved.

Description

Technical Field

[0001] This invention relates to the field of new material testing technology, and in particular to a method for detecting the content of copper foil coating. Background Technology

[0002] Electrolytic copper foil and rolled copper foil are key basic materials for manufacturing printed circuit boards (PCBs) and lithium battery negative electrode current collectors. During their production, electroplating treatments (such as blackening, passivation, and ashing) are typically applied to the copper foil surface to form a coating containing elements such as chromium, zinc, and nickel. This improves its oxidation resistance, chemical corrosion resistance, and adhesion to the substrate. The content of these elements in the coating directly affects the final performance of the copper foil. Therefore, rapid and accurate detection of the element content in the copper foil coating is crucial for product quality control and process optimization.

[0003] Currently, quantitative detection of elements in copper foil coatings typically employs inductively coupled plasma (ICP) spectroscopy. The specific method involves first dissolving the coating on the copper foil surface with an acid solution such as nitric acid, then bringing the solution to a constant volume, and finally performing the analysis using an ICP instrument.

[0004] However, during the process of dissolving the surface coating with nitric acid, the base copper foil and the coating will undergo co-solution. Since the mass of the copper foil base is much greater than that of the surface coating, the copper ions in the solution (…) The concentration of ) is extremely high, usually the element to be measured in the coating (such as , The concentration of copper ions in the matrix can be hundreds or even tens of thousands of times higher than that of copper foil. Such high concentrations of matrix copper ions can cause severe spectral interference in the ICP detection process, leading to suppression or enhancement of the measurement signal of the analyte, thus causing significant detection bias. Furthermore, subtle differences in the solubility of different samples can cause fluctuations in the concentration of copper ions in the solution. These fluctuations further amplify the unreliability of the detection results, making it difficult to guarantee the accuracy and reproducibility of the measurements. Therefore, developing a method to effectively overcome copper ion interference and improve the accuracy of ICP detection of copper foil coating content has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a method for detecting the content of copper foil plating that overcomes or at least partially solves the above problems. This method can solve the problem of low detection accuracy in existing copper foil plating content detection methods and achieve the goal of significantly improving the accuracy and reliability of plating element content detection.

[0006] Specifically, the present invention provides a method for detecting the content of copper foil plating, comprising the following steps: preparing a plurality of mixed standard solutions, the mixed standard solutions comprising copper ions and at least one kind of element ions to be detected, the copper ions in the plurality of mixed standard solutions having the same concentration and being the first preset concentration value, and the concentration of each of the element ions to be detected being gradiently changed, the first preset concentration value being greater than the concentration of the element ions to be detected; measuring the plurality of mixed standard solutions by using an inductively coupled plasma emission spectrometer to establish a standard curve between the theoretical value and the measured value of the concentration of each of the element ions to be detected; dissolving the plating layer on the surface of the copper foil to be detected by using nitric acid, and obtaining a sample solution to be detected after filtration; adding copper salt to the sample solution to be detected to make the concentration of copper ions reach a second preset concentration value, and obtaining an analysis solution to be detected, the difference between the second preset concentration value and the first preset concentration value being less than a preset difference value; measuring the analysis solution to be detected by using an inductively coupled plasma emission spectrometer to obtain the measured concentration of each of the element ions to be detected; obtaining the corrected content of each of the element ions to be detected according to the measured concentration of each of the element ions to be detected and the corresponding standard curve.

[0007] Optionally, the first preset concentration value is 5-35 g / L. The preset difference value is 0.1-2 g / L.

[0008] Optionally, the second preset concentration value is equal to the first preset concentration value.

[0009] Optionally, the adding of the copper salt to the sample solution to be detected to make the concentration of copper ions reach the second preset concentration value to obtain the analysis solution to be detected specifically comprises: obtaining the concentration of copper ions in the sample solution to be detected by using an inductively coupled plasma emission spectrometer to obtain an initial concentration value; obtaining the concentration difference between the initial concentration value and the second preset concentration value; adding the copper salt to the sample solution to be detected according to the concentration difference to make the concentration of copper ions reach the second preset concentration value to obtain the analysis solution to be detected.

[0010] Optionally, the measuring of the analysis solution to be detected by using an inductively coupled plasma emission spectrometer to obtain the measured concentration of the element ions to be detected comprises: measuring the analysis solution to be detected by using an inductively coupled plasma emission spectrometer to obtain a plurality of concentration data of each of the element ions to be detected; calculating the average value of the plurality of concentration data of each of the element ions to be detected; taking the average value as the measured concentration of the element ions to be detected.

[0011] Optionally, the process of dissolving the coating on the surface of the copper foil to be tested using nitric acid includes: Obtain the thickness of the coating on the surface of the copper foil to be tested; The dissolution time is obtained based on the thickness of the coating and / or the type of the element ion to be tested; Based on the dissolution time, nitric acid is used to dissolve the coating on the surface of the copper foil to be tested.

[0012] Optionally, the copper salt is copper nitrate; and / or At least one of the analyte element ions includes one or more of zinc, nickel, chromium, and cobalt ions; and / or The copper foil is rolled copper foil or electrolytic copper foil; and / or The thickness of the copper foil substrate is 2~200μm; and / or During the process of dissolving the coating on the surface of the copper foil to be tested using nitric acid, the dissolution time is 1~60s; Alternatively, the dissolution time is positively correlated with the thickness of the coating; and / or The operating parameters of the inductively coupled plasma atomic emission spectrometer include: RF power ranges from 1 to 1500W; The pump flow rate is 0.1~10 mL / min; The auxiliary gas flow rate is 0.1~2L / min; The atomizer flow rate is 0.1~2L / min.

[0013] Optionally, when at least one of the analyte ions is a zinc ion, and the first preset concentration value is 15 g / L, the relationship corresponding to the standard curve of the zinc ion concentration is: Where X1 is the measured value of zinc ion concentration; Y1 is the theoretical value of the zinc ion concentration; R1 is the first correlation coefficient.

[0014] Optionally, when at least one of the analyte ions includes zinc ions and nickel ions, and the first preset concentration value is 25 g / L: The relationship between the standard curve for the zinc ion concentration and the given concentration is as follows: The relationship corresponding to the standard curve of the nickel ion concentration is as follows: Where X2 is the measured concentration of zinc ions; Y2 is the theoretical value of the zinc ion concentration; X3 is the measured value of nickel ion concentration; Y3 is the theoretical value of the nickel ion concentration; R² is the second correlation coefficient; R3 is the third correlation coefficient.

[0015] Optionally, the operating parameters of the inductively coupled plasma atomic emission spectrometer include: The radio frequency power is 1100W; The pump flow rate is 0.7 mL / min; The auxiliary gas flow rate is 0.6 L / min; The atomizer flow rate is 0.5 L / min; The zinc test spectral line is 334.501 nm; The nickel test spectral line is 341.476 nm.

[0016] In the copper foil coating content detection method of this invention, by placing the standard curve and the analytical solution of the sample to be tested in a highly consistent copper ion matrix environment, spectral interference and matrix effects caused by differences and fluctuations in copper ion concentration are fundamentally eliminated, thereby significantly improving the accuracy and reliability of quantitative analysis of coating elements. This method requires no complex sample separation or purification steps, nor does it require the introduction of special equipment. Accurate detection can be achieved simply by optimizing the copper ion concentration control in the pretreatment process. It features simple operation, low cost, high efficiency, and stability, making it particularly suitable for large-scale quality monitoring in industrial settings. Furthermore, by actively controlling the background concentration of copper ions, random errors caused by dissolution differences and human operation are effectively reduced, greatly enhancing the repeatability and reproducibility of the detection results. This provides reliable data support for the refined control and continuous optimization of the production process, and provides crucial analytical assurance for the production of high-quality copper foil.

[0017] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0018] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic flowchart of a method for detecting the content of copper foil plating according to an embodiment of the present invention. Detailed Implementation

[0019] The following reference Figure 1This invention describes a method for detecting the content of copper foil plating according to an embodiment of the present invention. In this description, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included. In the description of this embodiment, references to terms such as "an embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that the 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. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0020] Figure 1 This is a schematic flowchart of a copper foil plating content detection method according to an embodiment of the present invention, as shown below. Figure 1 As shown, this embodiment of the invention provides a method for detecting the content of copper foil plating, which includes the following steps: Step S100: Prepare multiple mixed standard solutions; the mixed standard solutions include copper ions and at least one element ion to be tested; in the multiple mixed standard solutions, the concentration of copper ions is the same and is all at a first preset concentration value, and the concentration of each element ion to be tested varies in a gradient, with the first preset concentration value being greater than the concentration of the element ion to be tested; Step S200: Use an inductively coupled plasma atomic emission spectrometer to measure multiple mixed standard solutions and establish a standard curve between the theoretical and measured values ​​of the ion concentration of each analyte element. Step S300: Dissolve the coating on the surface of the copper foil to be tested using nitric acid, and obtain the sample solution after filtration; Step S400: Add copper salt to the sample solution to make the copper ion concentration reach the second preset concentration value to obtain the analytical solution to be tested; the difference between the second preset concentration value and the first preset concentration value is less than the preset difference; specifically, the difference here refers to the absolute value of the difference between the second preset concentration value and the first preset concentration value. Step S500: Use an inductively coupled plasma atomic emission spectrometer to measure the analytical solution to obtain the measured concentration of each analyte ion; Step S600: Based on the measured concentration of each element ion to be tested and the corresponding standard curve, obtain the corrected content of each element ion to be tested.

[0021] This embodiment provides a method for detecting the content of copper foil coating, which mainly includes two stages: standard curve establishment and sample testing and analysis. Specifically, firstly, in the standard curve establishment stage, a series of mixed standard solutions containing fixed high concentrations of copper ions and gradient concentrations of analytes are prepared. ICP detection is then performed on these mixed standard solutions to establish a standard curve between the theoretical and measured values ​​of the concentration of each analyte ion under a specific environment with strong copper ion interference. Secondly, in the sample testing and analysis stage, after dissolving the copper foil coating in nitric acid to obtain the sample solution, copper salt is added to adjust the copper ion concentration to a second preset value. ICP detection is then performed, and the test results are substituted into the corresponding standard curve to obtain the corrected content of the analyte ions, thereby determining the content of the analyte elements in the copper foil coating.

[0022] In this embodiment, the method fundamentally eliminates spectral interference and matrix effects caused by differences and fluctuations in copper ion concentration by placing the standard curve and the test sample in a highly consistent copper ion matrix environment, thereby significantly improving the accuracy and reliability of quantitative analysis of coating elements. This method requires no complex sample separation or purification steps, nor does it require special equipment. Accurate detection can be achieved simply by optimizing the copper ion concentration control in the pretreatment process. It is characterized by its ease of operation, low cost, high efficiency, and stability, making it particularly suitable for large-scale quality monitoring in industrial settings. Furthermore, by actively controlling the background copper ion concentration, random errors caused by dissolution differences and human operation are effectively reduced, greatly enhancing the repeatability and reproducibility of the test results. This provides reliable data support for the refined control and continuous optimization of the production process, and provides crucial analytical assurance for the production of high-quality copper foil.

[0023] In some embodiments of the present invention, the first preset concentration value is 5~35 g / L; the preset difference value is 0.1~2 g / L. For example, the first preset concentration value can be any one of 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, and 35 g / L.

[0024] Furthermore, in some embodiments of the present invention, the first preset concentration value is 10~30g / L.

[0025] In some embodiments of the present invention, the second preset concentration value is equal to the first preset concentration value. By making the copper ion concentration of the analytical solution to be tested and the mixed standard solution completely consistent, the error caused by the difference in copper ion concentration is completely eliminated, further enhancing the accuracy and repeatability of the detection results.

[0026] In some embodiments of the present invention, step S100 specifically includes: mixing a copper ion standard solution and a standard solution of at least one element ion to be tested in a volumetric flask of a predetermined capacity to prepare multiple mixed standard solutions. The copper ion standard solution is a commercially available solution, which may be a nitrate solution, and the solution medium is nitric acid. Preferably, the nitrate is of the same type as the copper salt in step S400. The standard solution of the element ion to be tested is a commercially available solution.

[0027] In some embodiments of the present invention, step S100 specifically includes: Multiple mixed standard solutions are prepared in a container using copper salt, salt containing ions of the element to be measured, and water, in a preset ratio.

[0028] In some embodiments of the present invention, step S500 specifically includes: Step S510: Use an inductively coupled plasma atomic emission spectrometer to measure the analytical solution to obtain multiple concentration data for each analyte element ion; Step S520: Calculate the average value of multiple concentration data for each element ion to be tested; Step S530: Use the average value as the measured concentration of the element ion to be measured.

[0029] This embodiment effectively improves the precision and reliability of the final detection results by adopting an operation process of taking multiple measurements and averaging them.

[0030] In some embodiments of the present invention, step S400 specifically includes: Step S410: Use an inductively coupled plasma atomic emission spectrometer to obtain the concentration of copper ions in the sample solution to obtain an initial concentration value; Step S420: Obtain the difference between the initial concentration value and the second preset concentration value; Step S430: Add copper salt to the sample solution to be tested according to the concentration difference, so that the copper ion concentration reaches the second preset concentration value, and obtain the analytical solution to be tested.

[0031] This embodiment provides a method for adjusting copper ion concentration. Specifically, firstly, the initial concentration value of the sample solution to be tested is accurately obtained as a baseline. Then, by calculating the quantitative difference between this initial concentration and a second preset concentration value, the precise addition of copper salt is achieved. This method transforms an operation that relies on experience-based estimation into a quantifiable and reproducible precise control process, which helps ensure that the analytical solution to be tested and the mixed standard solution used to establish the standard curve are in a highly consistent matrix environment. This not only fundamentally eliminates detection deviations caused by mismatches or fluctuations in background copper ion concentration, but also significantly improves the consistency and comparability of results between different operators and different batches of experiments, thereby ensuring the accuracy of the final corrected content data and the practical value of this method in quality control.

[0032] Furthermore, in some embodiments of the present invention, step S400 specifically includes: Use water to bring the sample solution to the preset volume to obtain a diluted solution. The concentration of copper ions in the constant-volume solution was measured using inductively coupled plasma atomic emission spectrometry to obtain the initial concentration value; Obtain the concentration difference between the initial concentration value and the second preset concentration value; Copper salt is added to the diluted solution based on the concentration difference to bring the copper ion concentration to a second preset value, thus obtaining the analytical solution to be tested.

[0033] Compared with the previous embodiment, this embodiment allows for more precise control of copper ion concentration by first adjusting the volume of the sample solution before performing subsequent measurements and additions.

[0034] In some embodiments of the present invention, the copper salt is copper nitrate. For example, copper nitrate can be copper nitrate trihydrate or other hydrated forms of copper nitrate. Since nitric acid is used to dissolve the copper foil coating during the sample pretreatment stage, the sample solution itself contains a large number of nitrate ions. Adding copper nitrate at this time will not introduce new anions into the system that may interfere with subsequent detection, thereby avoiding potential interference caused by the complexity of anion types and further ensuring the accuracy of the detection results.

[0035] In some embodiments of the present invention, the copper salt is copper sulfate. For example, copper sulfate can be copper sulfate pentahydrate, etc. Using copper sulfate can also achieve the purpose of supplementing copper ions, and it is suitable for copper foil samples in which the known coating composition does not contain or contains only trace amounts of elements that will form precipitates with sulfate ions.

[0036] In some embodiments of the present invention, in steps S200 and S500, the operating parameters of the inductively coupled plasma atomic emission spectrometer include: radio frequency power of 1~1500W; pump flow rate of 0.1~10mL / min; auxiliary gas flow rate of 0.1~2L / min; and nebulizer flow rate of 0.1~2L / min.

[0037] Furthermore, in some embodiments of the present invention, the radio frequency power is 1000~1200W; the pump flow rate is 0.3~1.2mL / min; the auxiliary gas flow rate is 0.3~1L / min; and the atomizer flow rate is 0.3~1L / min.

[0038] In some embodiments of the present invention, at least one element ion to be tested includes one or more of zinc, nickel, chromium, and cobalt ions.

[0039] In some embodiments of the present invention, the copper foil is rolled copper foil or electrolytic copper foil.

[0040] In some embodiments of the present invention, the thickness of the copper foil substrate is 2 to 200 μm. For example, the thickness of the copper foil substrate can be any one of 5 μm, 10 μm, 12 μm, 15 μm, 20 μm, 40 μm, 50 μm, 60 μm, 80 μm, 90 μm, 100 μm, 120 μm, 150 μm, and 200 μm.

[0041] In some embodiments of the present invention, the thickness of the coating is 0.1~30nm. For example, the thickness of the coating can be any one of 0.1nm, 0.2nm, 0.5nm, 1nm, 6nm, 10nm, 15nm, 18nm, 20nm, 25nm, 28nm, and 30nm.

[0042] In some embodiments of the present invention, during the process of dissolving the coating on the surface of the copper foil to be tested using nitric acid, the dissolution time is 1 to 60 seconds. For example, the dissolution time can be any one of 1 second, 5 seconds, 10 seconds, 15 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, and 60 seconds.

[0043] Preferably, the dissolution time is 2~30s.

[0044] In some embodiments of the present invention, during the process of dissolving the coating on the surface of the copper foil to be tested using nitric acid, the dissolution time is positively correlated with the thickness of the coating. That is, the thicker the coating, the longer the dissolution time. This embodiment can precisely control the dissolution process of the coating: ensuring complete dissolution of the coating and avoiding coating residue that could lead to deviations in the test results. This quantitative design significantly improves the accuracy of the test results and the reproducibility of the method, standardizes the operation, and can be adapted to products of different specifications.

[0045] In some embodiments of the present invention, the step of using nitric acid to dissolve the coating on the surface of the copper foil to be tested specifically includes the following steps: Step S310: Obtain the thickness of the coating on the surface of the copper foil to be tested; Step S320: Obtain the dissolution time based on the thickness of the coating and / or the type of the element ion to be measured; Step S330: Based on the dissolution time, use nitric acid to dissolve the coating on the surface of the copper foil to be tested.

[0046] Specifically, the type of analyte ion refers to the quantity and type of analyte ions to be tested in the coating. In step S320, the dissolution time is quickly determined using a lookup table method, reducing subjective human error. This embodiment determines the dissolution time of the coating with nitric acid based on at least one of the coating thickness and the type of analyte element in the coating, achieving precise control of the dissolution process. This ensures that the coating is fully and completely dissolved while minimizing unnecessary reaction time, thereby effectively improving detection efficiency.

[0047] The copper foil coating content detection method of the present invention will be further described in detail below with reference to specific embodiments.

[0048] Example 1 This embodiment provides a method for detecting the content of copper foil coating. This method is used to test the zinc content in the bright coating of an 18μm blackened rolled copper foil.

[0049] The method for detecting the copper foil coating content specifically includes the following steps: Step S11: Prepare five standard solutions by mixing the copper ion standard solution and zinc ion standard solution used in inductively coupled plasma atomic emission spectrometry (ICP-AES) in a 100 mL volumetric flask; in these five standard solutions, the copper ion concentration (C₂O₃) is [missing information]. The concentrations were all 15 g / L, and the zinc ion concentration was ( The concentrations were 0 mg / L, 0.3 mg / L, 0.5 mg / L, 0.7 mg / L, and 1 mg / L, respectively.

[0050] Step S12: Use inductively coupled plasma atomic emission spectrometry (ICP-AES) to measure the five mixed standard solutions described above, and establish a standard curve between the theoretical and measured values ​​of zinc ion concentration; the relationship corresponding to this standard curve of zinc ion concentration is: Where X1 is the measured concentration of zinc ions; Y1 is the theoretical concentration of zinc ions; and R1 is the first correlation coefficient. The operating parameters of the inductively coupled plasma atomic emission spectrometer include: RF power of 1100W, pump flow rate of 0.7mL / min, auxiliary gas flow rate of 0.6L / min, nebulizer flow rate of 0.5L / min, and the zinc test spectral line selected as 334.501nm.

[0051] Specifically, each mixed standard solution was tested three times, and the average of the three test data was taken as the test value of zinc ion concentration in that mixed standard solution. The theoretical and test data of the above five mixed standard solutions are shown in Table 1: Table 1 Step S13: Select a piece of blackened copper foil with dimensions of 10cm×10cm×18μm, dissolve and filter the smooth coating of the copper foil with nitric acid to obtain the sample solution to be tested. Step S14: Add copper nitrate trihydrate to the sample solution to make the copper ion concentration reach 15 g / L, and then make up to 100 mL with a volumetric flask to obtain the analytical solution to be tested. Step S15: Use an inductively coupled plasma atomic emission spectrometer to measure the analytical solution to obtain the measured concentration of zinc ions; Step S16: Calculate the corrected zinc ion content based on the measured concentration of zinc ions and the corresponding standard curve.

[0052] Specifically, in steps S15 and S16, as shown in Table 2, three sets of zinc ion concentration data were tested and calculated. The average value of the three sets of zinc ion concentration test values ​​was taken as the measured concentration of zinc ions. Based on the above measured concentration of zinc ions and the corresponding standard curve, the corrected zinc ion content (6.593 mg / m³) was obtained. 2 ).

[0053] Table 2 Example 2 This embodiment provides a method for detecting the content of copper foil plating. This method is used to test the zinc and nickel content of the rough surface plating on 18μm blackened rolled copper foil.

[0054] The method for detecting the copper foil coating content specifically includes the following steps: Step S21: Prepare five standard solutions by mixing the copper ion standard solution, zinc ion standard solution, and nickel ion standard solution used in inductively coupled plasma atomic emission spectrometry (ICP-AES) in a 100 mL volumetric flask; in these five standard solutions, the copper ion (… The concentrations were all 25 g / L, and the zinc ion concentration was ( The concentrations were 0 mg / L, 0.4 mg / L, 0.8 mg / L, 1.2 mg / L, and 1.6 mg / L, respectively; nickel ions ( The concentrations were 0 mg / L, 3 mg / L, 5 mg / L, 7 mg / L, and 10 mg / L, respectively.

[0055] Step S22: Use inductively coupled plasma atomic emission spectrometry (ICP-AES) to measure the five mixed standard solutions described above, and establish a standard curve between the theoretical and measured values ​​of zinc ion concentration; the relationship corresponding to this standard curve of zinc ion concentration is: A standard curve is established between the theoretical and measured values ​​of nickel ion concentration; the corresponding relationship for this standard curve is: Wherein, X2 is the measured concentration of zinc ions; Y2 is the theoretical concentration of zinc ions; X3 is the measured concentration of nickel ions; Y3 is the theoretical concentration of nickel ions; R2 is the second correlation coefficient; and R3 is the third correlation coefficient. The operating parameters of the inductively coupled plasma atomic emission spectrometer include: RF power of 1100W, pump flow rate of 0.7mL / min, auxiliary gas flow rate of 0.6L / min, nebulizer flow rate of 0.5L / min, zinc test line selected as 334.501nm, and nickel test line selected as 341.476nm.

[0056] Specifically, each mixed standard solution was tested three times. The average of the three zinc ion data was taken as the measured zinc ion concentration in the mixed standard solution, and the average of the three nickel ion data was taken as the measured nickel ion concentration. The theoretical and test data of the zinc ion concentration of the above five mixed standard solutions are shown in Table 3, and the theoretical and test data of the nickel ion concentration are shown in Table 4.

[0057] Table 3 Table 4 Step S23: Select a piece of blackened copper foil with dimensions of 10cm×10cm×18μm, dissolve the rough coating on the copper foil with nitric acid, filter it, and obtain the sample solution to be tested. Step S24: Add copper nitrate trihydrate to the sample solution to make the copper ion concentration reach 25 g / L, and then make up to 100 mL with a volumetric flask to obtain the analytical solution to be tested. Step S25: Use an inductively coupled plasma atomic emission spectrometer to measure the analytical solution to obtain the measured concentrations of zinc ions and nickel ions; Step S26: Calculate the corrected content of zinc ions based on the measured concentration of zinc ions and the corresponding standard curve; and calculate the corrected content of nickel ions based on the measured concentration of nickel ions and the corresponding standard curve.

[0058] Specifically, in steps S25 and S26, as shown in Table 5, a total of three sets of zinc ion concentration data and three sets of nickel ion concentration data were tested and calculated. The average of the three sets of zinc ion concentration test values ​​was taken as the measured zinc ion concentration, and the average of the three sets of nickel ion concentration test values ​​was taken as the measured nickel ion concentration. Based on the above measured zinc ion concentration and the corresponding standard curve, the zinc ion corrected content was found to be 16.526 mg / m³. 2 Based on the measured concentration of nickel ions and the corresponding standard curve, the corrected nickel ion content was found to be 59.044 mg / m³. 2 .

[0059] Table 5 Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A method for detecting a copper foil plating content, characterized by, The method comprises the following steps: preparing a plurality of mixed standard solutions, wherein the mixed standard solutions comprise copper ions and at least one kind of element ions to be detected, the concentration of the copper ions in the plurality of mixed standard solutions is the same and is a first preset concentration value, and the concentration of each kind of element ions to be detected varies in a gradient manner, and the first preset concentration value is greater than the concentration of the element ions to be detected; measuring the plurality of mixed standard solutions by using an inductively coupled plasma emission spectrometer to establish a standard curve between the theoretical value and the measured value of the concentration of each kind of element ions to be detected; dissolving the plating layer on the surface of the copper foil to be detected by using nitric acid to obtain a sample solution to be detected after filtration; adding copper salt to the sample solution to be detected to make the concentration of copper ions reach a second preset concentration value to obtain an analysis solution to be detected; the difference between the second preset concentration value and the first preset concentration value is less than a preset difference value; measuring the analysis solution to be detected by using the inductively coupled plasma emission spectrometer to obtain the measured concentration of each kind of element ions to be detected; obtaining the corrected content of each kind of element ions to be detected according to the measured concentration of each kind of element ions to be detected and the corresponding standard curve.

2. The method according to claim 1, wherein the first preset concentration value is 5-35 g / L; and the preset difference value is 0.1-2 g / L.

3. The method according to claim 2, wherein the second preset concentration value is equal to the first preset concentration value.

4. The method according to claim 1, wherein the step of adding copper salt to the sample solution to be detected to make the concentration of copper ions reach a second preset concentration value to obtain an analysis solution to be detected comprises the following steps: obtaining the initial concentration value of copper ions in the sample solution to be detected by using the inductively coupled plasma emission spectrometer; obtaining the concentration difference between the initial concentration value and the second preset concentration value; adding copper salt to the sample solution to be detected according to the concentration difference to make the concentration of copper ions reach the second preset concentration value to obtain the analysis solution to be detected.

5. The method according to claim 1, wherein the step of measuring the analysis solution to be detected by using the inductively coupled plasma emission spectrometer to obtain the measured concentration of the element ions to be detected comprises the following steps: measuring the analysis solution to be detected by using the inductively coupled plasma emission spectrometer to obtain a plurality of concentration data of each kind of element ions to be detected; calculating the average value of the plurality of concentration data of each kind of element ions to be detected; taking the average value as the measured concentration of the element ions to be detected.

6. The method according to claim 1, wherein the step of dissolving the plating layer on the surface of the copper foil to be detected by using nitric acid comprises the following steps: obtaining the thickness of the plating layer on the surface of the copper foil to be detected; obtaining the dissolution time according to the thickness of the plating layer and / or the type of the element ions to be detected; dissolving the plating layer on the surface of the copper foil to be detected by using nitric acid based on the dissolution time.

7. The method according to claim 1, wherein the copper salt is copper nitrate. ​ ​ ​ ​ ​ ​ ​ The at least one ion of the element to be detected includes one or more of zinc, nickel, chromium, and cobalt ions; and / or The copper foil is a rolled copper foil or an electrolytic copper foil; and / or The thickness of the copper foil substrate is 2-200 μm; and / or In the process of dissolving the plating layer on the surface of the copper foil with nitric acid, the dissolving time is 1-60 s; or the dissolving time is positively correlated with the thickness of the plating layer; and / or The working parameters of the inductively coupled plasma emission spectrometer include: The radio frequency power is 1-1500 W; The pump flow rate is 0.1-10 mL / min; The auxiliary gas flow rate is 0.1-2 L / min; The nebulizer flow rate is 0.1-2 L / min.

8. The method for detecting the plating layer content of a copper foil according to claim 1, wherein, when the at least one ion of the element to be detected is zinc ion and the first preset concentration value is 15 g / L, the relationship formula corresponding to the standard curve of the zinc ion concentration is: Y1 = R1X1 + b1, wherein, X1 is the measured value of the zinc ion concentration; Y1 is the theoretical value of the zinc ion concentration; and R1 is the first correlation coefficient.

9. The method for detecting the plating layer content of a copper foil according to claim 1, wherein, when the at least one ion of the element to be detected includes zinc ion and nickel ion and the first preset concentration value is 25 g / L: the relationship formula corresponding to the standard curve of the zinc ion concentration is: Y2 = R2X2 + b2, the relationship formula corresponding to the standard curve of the nickel ion concentration is: Y3 = R3X3 + b3, wherein, X2 is the measured value of the zinc ion concentration; Y2 is the theoretical value of the zinc ion concentration; X3 is the measured value of the nickel ion concentration; Y3 is the theoretical value of the nickel ion concentration; R2 is the second correlation coefficient; and R3 is the third correlation coefficient.

10. The method for detecting the plating layer content of a copper foil according to claim 1, wherein, the working parameters of the inductively coupled plasma emission spectrometer include: the radio frequency power is 1100 W; the pump flow rate is 0.7 mL / min; the auxiliary gas flow rate is 0.6 L / min; the nebulizer flow rate is 0.5 L / min; the zinc test spectral line is 334.501 nm; and the nickel test spectral line is 341.476 nm. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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