A cyclic voltammetry test method for improving the test precision of an additive for a carrier copper foil

Abstract

This invention relates to a cyclic voltammetric testing method for improving the accuracy of additive testing for carrier copper foil. The method involves adding standard solutions of known concentrations of additives at different gradients to a low-concentration production line test bath containing the additive. This increases the concentration of the additive in the mixed test bath to meet the analytical range of a Metrohm 894 cyclic voltammetric stripping analyzer. After multiple tests, the average value is calculated to obtain the concentration of the additive in the low-concentration production line test bath. Using this method, the concentration and consumption of additives in electroplating solutions for 1.5-3 μm peelable ultra-thin copper layers can be accurately tested. This facilitates continuous replenishment of the additive, maintaining it at a suitable concentration in the electroplating solution and improving product quality stability.

Description

Technical Field

[0001] This invention belongs to the field of electrolytic copper foil technology, and specifically relates to a cyclic voltammetry test method for improving the accuracy of additive testing for carrier copper foil. Background Technology

[0002] The thickness of the peelable ultrathin copper layer is generally 1.5-3μm. The background amount and consumption of additives required to thicken the copper layer by 1.5-3μm are relatively low compared with existing electrolytic copper foils with thicknesses of 12μm, 18μm, and 35μm. For example, the background concentration of a certain additive in the electrolyte required for the electrodeposition of copper layer in 18μm electrolytic green foil is 5-10mg / L. Then, the background concentration of a certain additive in the electrolyte required for the electrodeposition of copper layer in 1.5-3μm ultrathin copper layer is 1-3mg / L. Such a low additive concentration cannot be accurately measured by a cyclic voltammetric stripping analyzer, which is not conducive to production line quality monitoring. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a cyclic voltammetry test method for improving the accuracy of additive testing for carrier copper foil. Through this method, the concentration and consumption of additives in electroplating solutions for 1.5-3μm peelable ultrathin copper layers can be accurately tested, which facilitates the continuous replenishment of additives and keeps the additives in the electroplating solution at a suitable concentration, thereby improving the stability of product quality.

[0004] This invention provides a cyclic voltammetry testing method for improving the accuracy of testing additives for carrier copper foil, comprising the following steps: (1) Prepare standard stock solution; add additives to the standard stock solution to prepare standard solutions containing additives of different known concentrations; (2) A standard curve for an additive of a certain concentration was established using the DT method in a Swiss Metrohm 894 cyclic voltammetric dissolution analyzer. The standard solutions of other additives of different concentrations were tested to confirm that the test error was within 0.2 mg / L. (3) Take samples of the tank solution containing additives of unknown concentration from the production line and dilute them with deionized water; mix the diluted tank solution with standard solutions of other additives of different concentrations and shake well to obtain different test solutions; (4) In the Swiss Metrohm 894 cyclic voltammetric dissolution analyzer, the standard curve in step (2) is used to test the different test solutions in step (3) again, and the average value is taken to calculate the concentration of additives in the original tank solution of the production line.

[0005] Preferably, the standard solution in step (1) is a copper sulfate electrolyte with a copper ion concentration of 20-40 g / L, a sulfate ion concentration of 50-100 g / L, and a chloride ion concentration of 10-20 mg / L.

[0006] Preferably, the known concentration range of the additive in step (1) is 5-14 mg / L.

[0007] The key point of this invention is that, before using this method, the background concentration of additives in the electrolyte containing a 1.5-3μm peelable ultrathin copper layer is too low, below the detection limit of the cyclic voltammetric dissolution analyzer, making the test invalid. However, by mixing the standard solution containing known concentrations of additives at different gradients with the test solution and then testing, the additive concentration in the mixed test solution is increased, allowing for analysis and testing with the cyclic voltammetric dissolution analyzer. Furthermore, by setting different concentration gradients and testing multiple sets of data, the accuracy of the data is improved.

[0008] Beneficial effects By using the method of the present invention, the concentration and consumption of additives in the electroplating solution for 1.5-3μm peelable ultrathin copper layers can be accurately tested, which facilitates the continuous replenishment of additives and keeps the additives in the electroplating solution at a suitable concentration, thereby improving the stability of product quality. Attached Figure Description

[0009] Figure 1 The graph shows the test results of test liquid 1 in Example 1.

[0010] Figure 2 The graph shows the test results of test liquid 1 in Example 4.

[0011] Figure 3 The graph shows the test results of the test solution diluted 1 time for Comparative Example 1.

[0012] Figure 4 The graph shows the test results of the test solution diluted 1 time in Comparative Example 4. Detailed Implementation The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0013] Example 1 Step 1: Prepare the standard solution stock solution, which is a copper sulfate electrolyte containing 30 g / L copper ions, 75 g / L sulfate ions, and 10 mg / L chloride ions.

[0014] Step 2: Add polyethylene glycol to the above standard mother liquor to prepare standard solutions containing different concentrations of polyethylene glycol, namely 5 mg / L, 10 mg / L, 12 mg / L and 14 mg / L.

[0015] Step 3: Using the DT method in a Metrohm 894 cyclic voltammetric dissolution analyzer, a standard curve of 5 mg / L polyethylene glycol was established, and standard solutions of polyethylene glycol at different concentrations were backtested to confirm that the test error was within 0.2 mg / L.

[0016] Step 4: Prepare 100ml of test solution containing 0.5mg / L polyethylene glycol. Dilute with deionized water by 1:1 and shake well for 2min to obtain 200ml of diluted solution.

[0017] Step 5: Take 25ml of the 1-fold diluted bath solution and mix it with 25ml of the standard solution containing 10mg / L polyethylene glycol for 2 minutes to obtain test solution 1; take 25ml of the 1-fold diluted bath solution and mix it with 25ml of the standard solution containing 12mg / L polyethylene glycol for 2 minutes to obtain test solution 2; take 25ml of the 1-fold diluted bath solution and mix it with 25ml of the standard solution containing 14mg / L polyethylene glycol for 2 minutes to obtain test solution 3.

[0018] Step Six: Using the 5 mg / L standard curve of polyethylene glycol established and confirmed in Step Three, test the test solutions 1, 2, and 3 prepared in Step Five in the Swiss Metrohm 894 cyclic voltammetric dissolution analyzer, and record the results as x, y, and z, respectively.

[0019] Step 7: Through the dilution and mixing operations during the solution preparation process, the concentration of the test solution on the production line is equal to (x+y+z)*1.333-24, in mg / L. The test result of test solution 1 is as follows: Figure 1 As shown.

[0020] Example 2 The only difference is that in step four of Example 1, the 100ml test solution containing 0.5mg / L polyethylene glycol is replaced with 100ml of test solution containing 1mg / L polyethylene glycol; the other steps remain the same.

[0021] Example 3 The only difference is that the 100ml test solution containing 0.5mg / L polyethylene glycol in step four of Example 1 is replaced with 100ml test solution containing 2mg / L polyethylene glycol; the other operating steps are the same.

[0022] Example 4 The only difference is that in step four of Example 1, the 100ml test solution containing 0.5mg / L polyethylene glycol was replaced with 100ml of test solution containing 3mg / L polyethylene glycol. All other operating steps remained the same. The test results for test solution 1 are as follows: Figure 2 As shown.

[0023] Comparative Example 1 Step 1: Prepare the standard solution stock solution, which is a copper sulfate electrolyte containing 30 g / L copper ions, 75 g / L sulfate ions, and 10 mg / L chloride ions.

[0024] Step 2: Add polyethylene glycol to the above standard mother liquor to prepare standard solutions containing different concentrations of polyethylene glycol, namely 5 mg / L, 10 mg / L, 12 mg / L and 14 mg / L.

[0025] Step 3: Using the DT method in a Metrohm 894 cyclic voltammetric dissolution analyzer, a standard curve of 5 mg / L polyethylene glycol was established, and standard solutions of different concentrations of polyethylene glycol were tested to confirm that the test error was within 0.2 mg / L.

[0026] Step 4: Prepare 100ml of test solution containing 0.5mg / L polyethylene glycol, dilute with deionized water by 1:1 and shake well for 2min to obtain 200ml of test solution diluted by 1:1.

[0027] Step 5: Using a Metrohm 894 cyclic voltammetric dissolution analyzer, and employing the 5 mg / L polyethylene glycol standard curve established and validated in Step 3, test the 1-fold diluted test solution prepared in Step 4. The test results for the 1-fold diluted test solution are as follows: Figure 3 As shown.

[0028] Comparative Example 2 The only difference is that the 100ml test solution containing 0.5mg / L polyethylene glycol in step four of Comparative Example 1 is replaced with 100ml test solution containing 1mg / L polyethylene glycol; the other operating steps are the same.

[0029] Comparative Example 3 The only difference is that the 100ml test solution containing 0.5mg / L polyethylene glycol in step four of Comparative Example 1 is replaced with 100ml test solution containing 2mg / L polyethylene glycol; the other operating steps are the same.

[0030] Comparative Example 4 The only difference was that in Comparative Example 1, step four involved preparing 100 ml of a test bath solution containing 0.5 mg / L polyethylene glycol, which was replaced with 100 ml of a test bath solution containing 3 mg / L polyethylene glycol. All other operating steps remained the same. The test results after diluting the test bath solution by 1 time were as follows: Figure 4 As shown.

[0031] The above embodiments and comparative test data are as follows: The test results show that Comparative Examples 1-4 did not use the test method of this invention. When the additive concentration was low, it was outside the analytical range of the Metrohm 894 analyzer, resulting in invalid or significantly biased test results. Examples 1-4 used the test method of this invention. When the additive concentration was low, the additive concentration in the mixed test solution was increased by preparing a standard solution of known concentration and mixing it with the low-concentration test solution. This increased the additive concentration in the mixed test solution, allowing for analysis using the Metrohm 894 cyclic voltammetric dissolution analyzer. The difference between the test results and the actual results was ≤0.2 mg / L. Furthermore, different concentration gradients were set, and multiple sets of data were tested to improve data accuracy.

[0032] It should be noted that the test solution used in step four of Examples 1-4 and Comparative Examples 1-4 of this invention is a test solution with a known concentration of additives, prepared according to the production line solution preparation parameters. Using a test solution of known concentration is used to verify the feasibility and accuracy of the method of this invention. In actual production, step four only requires taking a production line test solution of unknown concentration and testing it using the method of this invention to determine the additive concentration in the production line solution. By comparing the test results at different time periods, the amount of additive consumed can be determined, facilitating further continuous replenishment of the additives and maintaining the additives in the electroplating solution at a suitable concentration, thereby improving product quality stability.

Claims

1. A cyclic voltammetry test method for improving the testing accuracy of additives for carrier copper foil, characterized in that, Includes the following steps: (1) Prepare standard stock solution; add additives to the standard stock solution to prepare standard solutions containing additives of different known concentrations; (2) A standard curve for an additive of a certain concentration was established using the DT method in a Swiss Metrohm 894 cyclic voltammetric dissolution analyzer. The standard solutions of other additives of different concentrations were tested to confirm that the test error was within 0.2 mg / L. (3) Take samples of the tank solution containing additives of unknown concentration from the production line and dilute them with deionized water; mix the diluted tank solution with standard solutions of other additives of different concentrations and shake well to obtain different test solutions; (4) In the Swiss Metrohm 894 cyclic voltammetric dissolution analyzer, the standard curve in step (2) is used to test the different test solutions in step (3) again, and the average value is taken to calculate the concentration of additives in the original tank solution of the production line.

2. The method according to claim 1, characterized in that, The standard solution in step (1) is a copper sulfate electrolyte with a copper ion concentration of 20-40 g / L, a sulfate ion concentration of 50-100 g / L, and a chloride ion concentration of 10-20 mg / L.

3. The method according to claim 1, characterized in that, The known concentration range of the additives in step (1) is 5-14 mg / L.

Images