Automatic titrimetric analysis method for preventing tin ions from interfering copper ions in tin plating solution

Abstract

The invention discloses an automatic titration analysis method for preventing tin ions from interfering copper ions in a tin plating solution, which comprises the following steps: step 1, sequentially adding deionized water and hydrogen peroxide into the tin plating solution, and stirring to obtain a tin precipitation solution; step 2, adding ammonia water into the tin precipitation solution, and recording a standard titration solution volume V when potential changes suddenly through an automatic titrator; and 3, calculating the concentration C of the copper ions. The copper ion content in the tin plating solution is detected by adopting an automatic titration analysis method, the accuracy is high, the operation is suggested, acetylene gas and open fire operation are not used, potential safety hazards are reduced, the stability and the repeatability are high, meanwhile, hydrogen peroxide is added, divalent tin ions and a standard titration solution are prevented from participating in a complexation reaction, and copper ion concentration detection is prevented from being influenced. The detection accuracy of the copper ion concentration is improved.

Description

Technical Field

[0001] The present application relates to the technical field of tin plating solution analysis methods for chip-on-film roll production, and in particular to an automatic titration analysis method for preventing tin ions from interfering with copper ions in tin plating solution. Background Art

[0002] Cu in tin plating solution 2+ The analysis is generally carried out using an atomic absorption spectrometer (AA), which is an instrumental analysis method based on the absorption of the characteristic spectral lines by the ground state atomic vapor of the element to be measured (the element to be measured is converted into atomic vapor under high temperature by methods such as flames and graphite furnaces). The characteristic spectral lines and the degree to which the spectral lines are weakened are used to perform qualitative and quantitative analysis of the element to be measured.

[0003] Atomic absorption spectrometry cannot analyze multiple elements at the same time, and the light source must be replaced when the measured elements are different; the linear range of the standard working curve is narrow (generally within an order of magnitude); the power-on self-test time is too long; sample pretreatment is troublesome; the flame method has a high temperature (2100℃~2400℃), and there is a risk of burns; and the flame used in atomic absorption spectrometry is generally burned directly in the atmosphere, and the dissociation of gases diffused from the outside into the flame will affect the flame temperature, thereby affecting the stability of the instrument analysis; the gas and fuel-supporting gas cylinders need to be replaced, and the gas cylinders require special storage and have a high risk factor and are prone to explosion.

[0004] In view of this, an automatic titration analysis method for preventing tin ions from interfering with copper ions in tin plating solution is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide an automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin-plating solution. Before the automatic titration analysis, divalent tin ions in the tin-plating solution are converted into tetravalent tin ions for precipitation, and then the copper ion concentration is analyzed and calculated by an automatic titrator, thereby solving the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention adopts the following solutions:

[0007] An automatic titration analysis method for preventing tin ions from interfering with copper ions in a tinning solution comprises the following steps:

[0008] Step 1, adding deionized water and hydrogen peroxide to the tin plating solution in sequence, and stirring to obtain a tin precipitation solution;

[0009] Step 2, adding ammonia water to the tin precipitation solution, and recording the volume V of the standard titrant when the potential suddenly changes by an automatic titrator;

[0010] Step 3: Calculate the concentration C of copper ions.

[0011] In this method, hydrogen peroxide is added to convert divalent tin ions in the tin plating solution into tetravalent tin ions. The reaction principle is as follows:

[0012] 2H2O2+Sn 2+ →SnO2+2H2O; in this reaction, hydrogen peroxide converts Sn in the tin plating solution 2+ Oxidized by hydrogen peroxide to SnO2 precipitation. Prevent Sn in the tin plating solution 2+ The copper ions react with the standard titration solution to affect the complexation reaction between the copper ions and the standard titration solution, thereby improving the accuracy of the method for detecting copper ions in the tin plating solution.

[0013] At the same time, the automatic titration method is used to analyze the copper ion concentration in the tin plating solution to ensure that the operation is simple and easy to execute. Acetylene gas and open flame are not used, which reduces safety hazards, reduces the time for instrument self-calibration and sample preparation, and effectively improves work efficiency.

[0014] More preferably, the concentration of the hydrogen peroxide is 4% to 6% by mass.

[0015] Further preferably, the volume ratio of the hydrogen peroxide solution to deionized water is 4-6:94-96.

[0016] More preferably, the stirring time is greater than or equal to 4 min.

[0017] Further preferably, the volume ratio of the ammonia water to the tin plating solution is 1 to 2:1.

[0018] Further preferably, in the step 2, the complex electrode is an I-371+R-171 complex electrode.

[0019] Further preferably, the standard titration solution is EDTA-Na2 solution.

[0020] Further preferably, the standard titration solution is an EDTA-Na2 solution with a concentration of 1 mol / L.

[0021] More preferably, the potential value when the potential suddenly changes is -40 mV to -150 mV.

[0022] Further preferably, the concentration calculation formula of the copper ions is:

[0023]

[0024] Wherein, C is the content of copper ions, in g / L;

[0025] F is the correction factor of the standard titration solution;

[0026] m is the sampling weight of the tin plating solution, in g;

[0027] Specific gravity is the density value of the tin plating solution;

[0028] V is the volume of the standard titrant in mL.

[0029] The beneficial effects of the present invention are as follows: the present invention detects the copper ion content in the tin-plating solution by adopting an automatic titration analysis method, has high accuracy, and has operation suggestions, does not use acetylene gas and open flame operation, reduces safety hazards, and has high stability and repeatability. At the same time, hydrogen peroxide is added to generate tetravalent tin ions from divalent tin ions in the tin-plating solution, prevents the divalent tin ions from participating in a complex reaction with a standard titration solution to affect the copper ion concentration detection, and improves the detection accuracy of the copper ion concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a process flow chart of the present invention.

[0031] Figure 2 This is a potential change curve diagram when automatic titration analysis is adopted in Example 1 of the present invention, wherein the X-axis is the titration amount and the Y-axis is the potential.

[0032] Figure 3 This is a comparison chart of the analysis of copper ions in tin plating solution detected by the present method and atomic absorption spectrometry in Example 2 of the present invention, wherein AA represents the use of atomic absorption spectrometry. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0035] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0036] Additionally, descriptions of well-known structures, functions, and configurations may be omitted for clarity and conciseness.One of ordinary skill in the art will recognize that various changes and modifications may be made to the examples described herein without departing from the spirit and scope of the present disclosure.

[0037] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0038] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0039] Example 1

[0040] This embodiment 1 is an automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution, referring to Figure 1 , including the following steps:

[0041] (1) adding deionized water and hydrogen peroxide to a tin plating solution in sequence, and stirring to obtain a tin precipitation solution;

[0042] Preferably, the concentration of the hydrogen peroxide is 4% to 6% by mass.

[0043] Preferably, the volume ratio of the hydrogen peroxide solution to deionized water is 4-6:94-96.

[0044] Preferably, the stirring time is greater than or equal to 4 min.

[0045] In this step, hydrogen peroxide is added to convert the divalent tin ions in the tin plating solution into tetravalent tin ions. The reaction principle is as follows:

[0046] 2H2O2+Sn 2+ →SnO2+2H2O; in this reaction, hydrogen peroxide converts Sn in the tin plating solution 2+ Oxidized by hydrogen peroxide to form SnO2 precipitate.

[0047] Since the EDTA-Na2 standard titration solution is easy for metal ions to undergo complexation reaction, the metal ions in the tin plating solution, except for Cu 2 + Sn 2+ It will also react with the EDTA-Na2 standard titration solution. Before titration, hydrogen peroxide is added to make all the Sn in the tin plating solution 2+ SnO2 precipitation is generated to prevent Sn 2+ It undergoes complexation reaction with EDTA-Na2.

[0048] (2) adding ammonia water to the tin precipitation solution, and recording the volume V of the standard titrant when the potential suddenly changes by an automatic titrator.

[0049] Preferably, the volume ratio of the ammonia water to the tin plating solution is 1 to 2:1.

[0050] Preferably, the complex electrode is an I-371+R-171 complex electrode.

[0051] The standard titration solution is EDTA-Na2 solution. The concentration of the standard titration solution is 1 mol / L.

[0052] The potential value when the potential suddenly changes is -40mV to -150mV.

[0053] Among them, the automatic titrator AT-710 was used, and the standard titration solution and Cu 2+ The response principle is:

[0054] Cu 2+ +2H2Y - →Cu(Y)2 2- +4H + .

[0055] It should be noted that a reference electrode is also provided during the titration process, which is mainly used as a reference comparison electrode. This is a prior art and will not be described in detail here.

[0056] EDTA-Na2 is easily complexed with metal ions and the OPR electrode is used to detect the potential of the solution. When the potential jumps, refer to Figure 2 , and the titration endpoint is reached, and the volume V of the standard titrant is recorded at the same time.

[0057] (3) Calculate the concentration C of copper ions.

[0058] Preferably, the concentration of copper ions is calculated as follows:

[0059]

[0060] Wherein, C is the content of copper ions, in g / L;

[0061] F is the correction factor of the standard titration solution;

[0062] m is the sampling weight of the tin plating solution, in g;

[0063] Specific gravity is the density value of the tin plating solution, and the specific density value of the tin plating solution is used in the calculation;

[0064] V is the volume of the standard titrant in mL.

[0065] Example 2

[0066] This Example 2 is a verification analysis of the stability, variability and repeatability of copper ions in the tin plating solution using the present method and a conventional atomic absorption spectrometer.

[0067] 1. Stability verification

[0068] During the production of chip-on-film tape, 50 groups of tinning solutions were continuously monitored, divided into groups of 25, and analyzed synchronously using this method and atomic absorption spectrometer. Figure 3 The results showed that there was no significant difference in the copper ion content obtained using the two methods.

[0069] 2. Difference Verification

[0070] Two groups of tin-plating solutions with different copper ion concentrations were prepared, and the copper ion concentration in the tin-plating solution was measured using this method and an atomic absorption spectrometer, respectively. The comparative analysis results are shown in the following table:

[0071] Table 1 Difference data of two analytical methods for copper ions in tinning solution

[0072] Concentration gradient 1 3 5 9 11 Actual blending concentration 0.97 3.10 5.67 9.62 11.57 AA content (g / L) 1.03 3.03 5.50 8.95 11.04 AA difference absolute value (g / L) 0.06 0.07 0.17 0.67 0.54 Automatic titrator content (g / L) 0.97 3.03 5.53 9.42 11.39 Absolute value of titration difference (g / L) 0.00 0.07 0.14 0.20 0.18

[0073] It should be noted that AA indicates the use of an atomic absorption spectrometer.

[0074] According to Table 1, as the copper ion concentration increases, the error detected by atomic absorption spectrometer gradually increases, and its maximum error value can reach 0.67g / L; while the detection error of automatic titration analysis by automatic titrator tends to be stable, and the maximum error value is only 0.20g / L, which is much lower than that of atomic absorption spectrometer, and the copper ion detected is closer to the concentration in the actual tin plating solution. This shows that the copper ion concentration detected by this method is highly accurate.

[0075] 3. Repeatability verification

[0076] In the production process of chip-on-film tape, two groups of tin plating solutions were taken and the copper ion concentration was detected by this automatic titration analysis method. Each group was measured 10 times. The test results are shown in the following table:

[0077] Table 2 Repeatability data of automatic titration analysis method

[0078]

[0079]

[0080] According to Table 2, after each group was measured 10 times, the RSD values ​​of the two groups of samples were less than 1%, indicating that this method has good repeatability.

[0081] Example 3

[0082] This Example 3 is an anti-interference verification of adding hydrogen peroxide. Two groups of tin plating solutions with different copper ion concentrations are prepared, namely an experimental group (adding hydrogen peroxide) and a comparative group (not adding hydrogen peroxide). The copper ion concentration in the tin plating solution is determined using this method respectively. The comparative analysis results are shown in the following table:

[0083] Table 3 Effect of hydrogen peroxide on the concentration of copper ions detected in tinning solution

[0084] Concentration gradient 1 3 5 9 11 Actual blending concentration 0.97 3.10 5.67 9.62 11.57 Experimental Group 0.97 3.03 5.53 9.42 11.39 Comparison group - - - - -

[0085] According to Table 3, the difference between the copper ion concentration after adding hydrogen peroxide and the actual fine-mixed concentration is as low as 0.00, and the copper ion concentration in the tin-plating solution is not detected without adding hydrogen peroxide, indicating that the addition of hydrogen peroxide can prevent the interference of tin ions in the tin-plating solution on the detection of copper ions, thereby improving the detection accuracy of copper ions.

[0086] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution, characterized in that: The following steps are involved: Step 1, adding deionized water and hydrogen peroxide to the tin plating solution in sequence, and stirring to obtain a tin precipitation solution; Step 2, adding ammonia water to the tin precipitation solution, and recording the volume V of the standard titrant when the potential suddenly changes by an automatic titrator; Step 3: Calculate the concentration C of copper ions.

2. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 1, characterized in that: The mass percentage of the hydrogen peroxide concentration is 4% to 6%.

3. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 1, characterized in that: The volume ratio of the hydrogen peroxide to the deionized water is 4-6:94-96.

4. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 1, characterized in that: The stirring time is greater than or equal to 4 minutes.

5. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 1, characterized in that: The volume ratio of the ammonia water to the tin plating solution is 1 to 2:

1.

6. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 1, characterized in that: In the step 2, the complex electrode is an I-371+R-171 complex electrode.

7. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 1, characterized in that: The standard titration solution is EDTA-Na2 solution.

8. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 7, characterized in that: The standard titration solution is EDTA-Na2 solution with a concentration of 1 mol / L.

9. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 7, characterized in that: The potential value when the potential suddenly changes is -40mV to -150mV.

10. The automatic titration analysis method for preventing tin ions from interfering with copper ions in a tin plating solution according to claim 7, characterized in that: The concentration calculation formula of the copper ion is: Wherein, C is the content of copper ions, in g / L; F is the correction factor of the standard titration solution; m is the sampling weight of the tin plating solution, in g; Specific gravity is the density value of the tin plating solution; V is the volume of the standard titrant in mL.

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