Cu-ITO etching solution and preparation method thereof

Abstract

The application belongs to the technical field of etching liquid, and specifically discloses a Cu-ITO etching liquid, which comprises the following components in percentage by mass: 8-18% of hydrogen peroxide, 3-6% of sulfonic acid derivative, 0.5-1.5% of organic weak oxidizing agent, 0.1-2% of corrosion inhibitor, 0.05-1% of hydrogen peroxide stabilizer, 1-3% of surfactant, and the balance of water. The Cu-ITO etching liquid is composed of hydrogen peroxide, sulfonic acid derivative, organic weak oxidizing agent, corrosion inhibitor, hydrogen peroxide stabilizer and surfactant, and the components interact with each other, so that the etching liquid can etch the Cu-ITO substrate in one step, has the excellent characteristics of long service life and stable etching performance, and is green, environmentally friendly and less polluting.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of etching solution, and particularly relates to a Cu-ITO etching solution and a preparation method thereof. BACKGROUND

[0002] In a liquid crystal display, many of the array gate electrodes are composed of a base ITO material and a copper layer deposited on the surface thereof. Since the copper layer and the ITO layer need to be etched by using different etching solutions, exposure, development and etching are performed in two masks, and the copper layer is etched first and then the ITO layer is etched, which not only requires two kinds of etching solutions, but also needs to add a pre-etching solution removal process, an etching interface cleaning process and a post-etching solution adding process, etc., so that the mask process is complicated, resulting in a long production cycle and high process cost. If the multilayer film of the copper layer and the ITO layer can be etched together, the production efficiency can be greatly improved, and the production cost can be effectively reduced.

[0003] At present, KR1020220119564A discloses an etching solution composition for a copper-based metal layer and a metal oxide layer and an etching method thereof, based on the total weight of the etchant composition, 5-25% by weight of hydrogen peroxide; 0.01-1% by weight of a fluorinated compound; 0.1-5% by weight of an azole compound; 0.1-5% by weight of a water-soluble compound containing nitrogen and a carboxyl group in one molecule; 0.1-5% by weight of a sulfonic acid compound; 0.01-5% by weight of a polyol type surfactant; and the balance is water; the etching solution formula can etch the copper layer and the ITO layer in one step, the formula includes hydrogen fluoride and nitric acid, in the etching process, hydrogen fluoride can effectively control the etching rate of Cu and ITO, and fine pattern transfer is realized; however, since hydrogen fluoride is easy to dissociate fluorine ions in water, fluorine ions accumulate in the etching waste liquid, which not only increases the difficulty and cost of waste liquid treatment, but also may cause long-term pollution to water bodies and ecosystems; nitric acid has strong oxidizing property and volatility, can accelerate the etching reaction and improve the etching rate, but with the volatilization of nitric acid, the pH value and the composition ratio of the etching solution will change, the service life of the etching solution is shortened, the stability of etching is decreased, and the ITO layer cannot be etched. SUMMARY

[0004] The purpose of the present application is to provide a Cu-ITO etching solution to solve the problems of reduced service life of the etching solution and insufficient etching performance stability in the prior art.

[0005] To achieve the above technical purposes and effects, the present application realizes the following technical solutions:

[0006] In a first aspect, the present application provides a Cu-ITO etching solution, comprising the following components in percentage by mass: 8-18% of hydrogen peroxide, 3-6% of sulfonic acid derivative, 0.5-1.5% of organic weak oxidant, 0.1-2% of corrosion inhibitor, 0.05-1% of hydrogen peroxide stabilizer, 1-3% of surfactant, and the balance being water.

[0007] Further, a Cu-ITO etching solution, comprising the following components in percentage by mass: 12-16% of hydrogen peroxide, 4.5-5.5% of sulfonic acid derivative, 0.75-1.25% of organic weak oxidant, 0.5-1.5% of corrosion inhibitor, 0.1-0.5% of hydrogen peroxide stabilizer, 1.5-2.5% of surfactant, and the balance being water.

[0008] Further, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)azenediyl) bis(methylene) benzene sulfonic acid.

[0009] Still further, the chemical structure of the 4,4'-((4-sulfophenyl)azenediyl) bis(methylene) benzene sulfonic acid is shown in formula (I):

[0010]

[0011] Further, the organic weak oxidant is nicotinamide-N-oxide.

[0012] Further, the mass ratio of the sulfonic acid derivative to the organic weak oxidant is (4-6):1.

[0013] Further, the corrosion inhibitor is at least one of benzotriazole, benzimidazole, benzochinoline, benzopyridine, benzopyrazine, and benzisoxazole.

[0014] Further, the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenyl urea and / or 3-aminopropyl phosphonic acid.

[0015] Further, the surfactant is at least one of alkyl phenol polyoxyethylene ether, polyethylene glycol, polyether modified polysiloxane, fatty alcohol polyoxyethylene ether, and fatty acid polyoxyethylene ether.

[0016] In a second aspect, the present application provides a preparation method of a Cu-ITO etching solution, comprising the following steps:

[0017] S1, according to the Cu-ITO etching solution formula, weighing hydrogen peroxide, sulfonic acid derivative, organic weak oxidant, corrosion inhibitor, hydrogen peroxide stabilizer, surfactant, and water;

[0018] S2, the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water are stirred at room temperature until all materials are completely dissolved to prepare a mixed solution;

[0019] S3, the surfactant is added to the mixed solution obtained in step S2, and stirred at room temperature, and then returned to room temperature, and the hydrogen peroxide and the organic weak oxidizing agent are added and stirred at room temperature until all materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0020] Compared with the prior art, the beneficial effects of the present application are:

[0021] 1, the Cu-ITO etching solution provided by the present application comprises hydrogen peroxide, sulfonic acid derivative, organic weak oxidizing agent, corrosion inhibitor, hydrogen peroxide stabilizer and surfactant, when the etching solution contacts with the Cu-ITO substrate, the hydrogen peroxide rapidly undergoes redox reaction with the copper layer to oxidize the copper into copper ions, after the copper layer is etched away, the sulfonic acid derivative starts to react with ITO, so that the indium and tin in ITO enter the solution in the form of ions, thereby realizing etching of the ITO layer.

[0022] 2, in the present application, the sulfonic acid derivative is 4,4'-((4-sulfophenyl) aza diyl) bis(methylene) benzene sulfonic acid, the sulfonic group and the carboxyl group can react with indium tin oxide, thereby destroying the stability of the ITO crystal and making it more easily etched by the etching solution, effectively improving the etching residue removal effect on ITO; at the same time, 4,4'-((4-sulfophenyl) aza diyl) bis(methylene) benzene sulfonic acid can undergo complexation reaction with copper ions, on the one hand, it can orderly control the etching rate of Cu and ITO to avoid excessive etching, which is helpful to accurately control the etching degree of Cu-ITO substrate, on the other hand, it can improve the stability of the etching solution and prolong the service life of the etching solution.

[0023] 3, in the present application, the organic weak oxidizing agent is nicotinamide-N-oxide, which has weak oxidizing property, and can better etch the Cu-ITO substrate in combination with hydrogen peroxide and sulfonic acid derivative, and nicotinamide-N-oxide can capture copper ions in a directional manner to prevent copper ions from catalyzing the decomposition of hydrogen peroxide, thereby stabilizing the performance of the etching solution and prolonging the service life of the etching solution.

[0024] 4, in the present application, the sulfonic acid derivative and the organic weak oxidizing agent are added to the etching solution in a specific mass ratio, and interact with each other to stabilize the etching performance, effectively adjust the etching rate, improve the etching uniformity, and obtain a more flat etching surface. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0026] Figure 1 This is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Example 1 of the present invention;

[0027] Figure 2 is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Example 2 of the present invention;

[0028] Figure 3 is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Example 3 of the present invention;

[0029] Figure 4 is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Example 4 of the present invention;

[0030] Figure 5 is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Example 5 of the present invention;

[0031] Figure 6 This is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Comparative Example 1 of the present invention;

[0032] Figure 7 This is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Comparative Example 2 of the present invention;

[0033] Figure 8 This is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Comparative Example 3 of the present invention;

[0034] Figure 9 This is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Comparative Example 4 of the present invention;

[0035] Figure 10 This is a SEM image of a Cu-ITO substrate after being etched by the Cu-ITO etching solution provided in Comparative Example 5 of the present invention. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] Example 1

[0038] The embodiment provides a Cu-ITO etching solution, which comprises the following raw materials in mass fraction: 8% of hydrogen peroxide, 6% of a sulfonic acid derivative, 1.5% of an organic weak oxidizing agent, 0.1% of a corrosion inhibitor, 0.05% of a hydrogen peroxide stabilizer, 1% of a surfactant, and the balance being water;

[0039] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid; the organic weak oxidizing agent is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; and the surfactant is an alkylphenol polyoxyethylene ether.

[0040] The embodiment further provides a preparation method of the Cu-ITO etching solution, which comprises the following steps:

[0041] S1, respectively, take the respective amount of each component;

[0042] S2, the sulfonic acid derivative, the corrosion inhibitor, the hydrogen peroxide stabilizer and water are stirred at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0043] S3, the surfactant is added to the mixed solution obtained in step S2, and stirred at room temperature, and then returned to room temperature. The hydrogen peroxide and the organic weak oxidizing agent are added and stirred at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0044] Embodiment 2

[0045] The embodiment provides a Cu-ITO etching solution, which comprises the following raw materials in mass fraction: 8% of hydrogen peroxide, 6% of a sulfonic acid derivative, 1.5% of an organic weak oxidizing agent, 0.1% of a corrosion inhibitor, 0.05% of a hydrogen peroxide stabilizer, 1% of a surfactant, and the balance being water;

[0046] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid; the organic weak oxidizing agent is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; and the surfactant is an alkylphenol polyoxyethylene ether.

[0047] The embodiment further provides a preparation method of the Cu-ITO etching solution, which comprises the following steps:

[0048] S1, respectively, take the respective amount of each component;

[0049] S2, the sulfonic acid derivative, the corrosion inhibitor, the hydrogen peroxide stabilizer and water are stirred at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0050] S3, adding the surfactant to the mixed solution obtained in step S2, stirring at room temperature, returning to room temperature, adding hydrogen peroxide and the organic weak oxidizing agent, and stirring at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0051] Example 3

[0052] The embodiment provides a Cu-ITO etching solution, which comprises the following raw materials in mass fraction: hydrogen peroxide 15%, sulfonic acid derivative 5.1%, organic weak oxidizing agent 1%, corrosion inhibitor 1%, hydrogen peroxide stabilizer 0.35%, surfactant 2%, and the balance being water.

[0053] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azenediyl)bis(methylene)dibenzoic acid; the organic weak oxidizing agent is nicotinamide-N-oxide; the corrosion inhibitor is a mixture of benzotriazole and benzopyrazine in a mass ratio of 1:1; the hydrogen peroxide stabilizer is a mixture of 1,3-diethyl-1,3-diphenylurea and 3-aminopropyl phosphonic acid in a mass ratio of 1:1; and the surfactant is polyether-modified polysiloxane.

[0054] The embodiment also provides a preparation method of the Cu-ITO etching solution, which comprises the following steps.

[0055] S1, respectively weighing each component in a respective amount;

[0056] S2, stirring the sulfonic acid derivative, the corrosion inhibitor, the hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0057] S3, adding the surfactant to the mixed solution obtained in step S2, stirring at room temperature, returning to room temperature, adding hydrogen peroxide and the organic weak oxidizing agent, and stirring at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0058] Example 4

[0059] The embodiment provides a Cu-ITO etching solution, which comprises the following raw materials in mass fraction: hydrogen peroxide 16%, sulfonic acid derivative 4.5%, organic weak oxidizing agent 0.75%, corrosion inhibitor 1.5%, hydrogen peroxide stabilizer 0.5%, surfactant 2.5%, and the balance being water.

[0060] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azenediyl)bis(methylene)dibenzoic acid; the organic weak oxidizing agent is nicotinamide-N-oxide; the corrosion inhibitor is benzopyrazine; the hydrogen peroxide stabilizer is a mixture of 1,3-diethyl-1,3-diphenylurea and 3-aminopropyl phosphonic acid in a mass ratio of 2:1; and the surfactant is a fatty alcohol polyoxyethylene ether.

[0061] The embodiment also provides a preparation method of the Cu-ITO etching solution, comprising the following steps:

[0062] S1, respectively weighing each component in a respective amount;

[0063] S2, stirring the sulfonic acid derivative, the corrosion inhibitor, the hydrogen peroxide stabilizer and water at room temperature until all materials are completely dissolved to obtain a mixed solution;

[0064] S3, adding the surfactant to the mixed solution obtained in step S2 and stirring at room temperature, returning to room temperature, adding the hydrogen peroxide and the organic weak oxidizing agent, and stirring at room temperature until all materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0065] Example 5

[0066] The embodiment provides a Cu-ITO etching solution, comprising the following mass fractions of raw materials: 18% of hydrogen peroxide, 3% of a sulfonic acid derivative, 0.5% of an organic weak oxidizing agent, 2% of a corrosion inhibitor, 1% of a hydrogen peroxide stabilizer, 3% of a surfactant, and the balance being water;

[0067] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azenediyl)bis(methylene)dibenzoic acid, the organic weak oxidizing agent is nicotinamide-N-oxide, the corrosion inhibitor is benzoquinoline, the hydrogen peroxide stabilizer is obtained by mixing 1,3-diethyl-1,3-diphenylurea and 3-aminopropyl phosphonic acid at a mass ratio of 1:2, and the surfactant is a fatty acid polyoxyethylene ether.

[0068] The embodiment also provides a preparation method of the Cu-ITO etching solution, comprising the following steps:

[0069] S1, respectively weighing each component in a respective amount;

[0070] S2, stirring the sulfonic acid derivative, the corrosion inhibitor, the hydrogen peroxide stabilizer and water at room temperature until all materials are completely dissolved to obtain a mixed solution;

[0071] S3, adding the surfactant to the mixed solution obtained in step S2 and stirring at room temperature, returning to room temperature, adding the hydrogen peroxide and the organic weak oxidizing agent, and stirring at room temperature until all materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0072] Comparative Example 1

[0073] The comparative example provides a Cu-ITO etching solution and a preparation method thereof, which is different from the example 1 in that the sulfonic acid derivative in the comparative example is 4-aminobenzenesulfonic acid, and the specific preparation method is as follows:

[0074] A Cu-ITO etching solution, comprising raw materials in the following mass fractions: hydrogen peroxide 8%, sulfonic acid derivative 6%, organic weak oxidizing agent 1.5%, corrosion inhibitor 0.1%, hydrogen peroxide stabilizer 0.05%, surfactant 1%, and the balance being water;

[0075] The sulfonic acid derivative is 4-aminobenzenesulfonic acid; the organic weak oxidizing agent is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; and the surfactant is alkylphenol polyoxyethylene ether.

[0076] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0077] S1, respectively weighing each component in a respective amount;

[0078] S2, stirring the sulfonic acid derivative, the corrosion inhibitor, the hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0079] S3, adding the surfactant to the mixed solution obtained in step S2 and stirring at room temperature, returning to room temperature, adding hydrogen peroxide and the organic weak oxidizing agent, and stirring at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0080] Comparative Example 2

[0081] This comparative example provides a Cu-ITO etching solution and a preparation method thereof, which is different from Example 1 in that the organic weak oxidizing agent in this comparative example is N-methylmorpholine-N-oxide, and the specific preparation method is as follows:

[0082] A Cu-ITO etching solution, comprising raw materials in the following mass fractions: hydrogen peroxide 8%, sulfonic acid derivative 6%, organic weak oxidizing agent 1.5%, corrosion inhibitor 0.1%, hydrogen peroxide stabilizer 0.05%, surfactant 1%, and the balance being water;

[0083] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azenediyl)bis(methylene)dibenzoic acid; the organic weak oxidizing agent is N-methylmorpholine-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; and the surfactant is alkylphenol polyoxyethylene ether.

[0084] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0085] S1, respectively weighing each component in a respective amount;

[0086] S2, the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water are stirred at room temperature until all materials are completely dissolved to obtain a mixed solution;

[0087] S3, the surfactant is added to the mixed solution obtained in step S2, and stirred at room temperature, and returned to room temperature. Hydrogen peroxide and organic weak oxidizing agent are added and stirred at room temperature until all materials are uniformly mixed to obtain a Cu-ITO etching solution.

[0088] Comparative Example 3

[0089] This comparative example provides a Cu-ITO etching solution and a preparation method thereof, which is different from Example 1 in that in this comparative example, the sulfonic acid derivative is 7%, and the organic weak oxidizing agent is 1%, as follows:

[0090] A Cu-ITO etching solution, comprising the following mass fractions of raw materials: hydrogen peroxide 8%, sulfonic acid derivative 7%, organic weak oxidizing agent 1%, corrosion inhibitor 0.1%, hydrogen peroxide stabilizer 0.05%, surfactant 1%, and the balance being water;

[0091] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azenediyl) bis(methylene) diphenylcarboxylic acid; the organic weak oxidizing agent is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; and the surfactant is alkylphenol polyoxyethylene ether.

[0092] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0093] S1, each component is weighed according to the amount required;

[0094] S2, the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water are stirred at room temperature until all materials are completely dissolved to obtain a mixed solution;

[0095] S3, the surfactant is added to the mixed solution obtained in step S2, and stirred at room temperature, and returned to room temperature. Hydrogen peroxide and organic weak oxidizing agent are added and stirred at room temperature until all materials are uniformly mixed to obtain a Cu-ITO etching solution.

[0096] Comparative Example 4

[0097] This comparative example provides a Cu-ITO etching solution and a preparation method thereof, which is different from Example 1 in that in this comparative example, the sulfonic acid derivative is 1%, and the organic weak oxidizing agent is 5.5%, as follows:

[0098] A Cu-ITO etching solution, comprising raw materials in the following mass fractions: hydrogen peroxide 8%, sulfonic acid derivative 1%, organic weak oxidizing agent 5.5%, corrosion inhibitor 0.1%, hydrogen peroxide stabilizer 0.05%, surfactant 1%, and the balance being water;

[0099] The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azenediyl)bis(methylene)dibenzoic acid; the organic weak oxidizing agent is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; and the surfactant is alkylphenol polyoxyethylene ether.

[0100] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0101] S1, respectively weighing each component in a respective amount;

[0102] S2, stirring the sulfonic acid derivative, the corrosion inhibitor, the hydrogen peroxide stabilizer, and the water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0103] S3, adding the surfactant to the mixed solution obtained in step S2 and stirring at room temperature, returning to room temperature, adding hydrogen peroxide and the organic weak oxidizing agent, and stirring at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0104] Comparative Example 5

[0105] This comparative example provides a Cu-ITO etching solution and a preparation method thereof, specifically as follows:

[0106] A Cu-ITO etching solution, comprising raw materials in the following mass fractions: hydrogen peroxide 8%, nitric acid 6%, hydrogen fluoride 1.5%, corrosion inhibitor 0.1%, hydrogen peroxide stabilizer 0.05%, surfactant 1%, and the balance being water;

[0107] The corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; and the surfactant is alkylphenol polyoxyethylene ether.

[0108] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0109] S1, respectively weighing each component in a respective amount;

[0110] S2, stirring the nitric acid, the hydrogen fluoride, the corrosion inhibitor, the hydrogen peroxide stabilizer, and the water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0111] S3, adding a surfactant to the mixed solution obtained in step S2, stirring at room temperature, returning to room temperature, adding hydrogen peroxide, and stirring at room temperature until all the materials are uniformly mixed to obtain a Cu-ITO etching solution.

[0112] Performance test

[0113] The Cu-ITO etching solutions provided by Examples 1-5 and Comparative Examples 1-5 were subjected to performance tests, and the relevant test items and test procedures are as follows.

[0114] (1) Stability test of etching solution

[0115] The etching solution was stored at room temperature in the dark, and the etching rate of the etching solution was investigated after 8h, 16h and 24h, respectively, to investigate its stability. The test method of etching rate was as follows: five points were selected on the surface of the Cu sample (or ITO sample) for testing by the four-probe method, and the average value was taken to determine the initial thickness of the material; the etching solution obtained by Examples 1-5 and Comparative Examples 1-5 was used to soak the sample at 33℃, and the soaking time was 50s, and then the Cu sample (or ITO sample) with the expected thickness was obtained; the etched sample was washed twice in ultrapure water, and the washing step was completed; the etched sample was tested on the surface by the four-probe method, and the average value was taken after five points were selected to determine the thickness of the thinned sample and the difference between the thickness of the etched sample and the thickness of the sample before etching, and the etching rate of the sample was obtained by dividing the etching time of the sample. The specific results are shown in Table 1.

[0116] Table 1

[0117]

[0118] (2) Etching effect test of etching solution

[0119] The etching effect of the etching solution obtained by Examples 1-5 and Comparative Examples 1-5 was tested, and the Cu-ITO substrate (Cu layer: ITO layer: ) was etched at 33℃ using an etching machine, and the etching effect of the etching solution was evaluated by observing the Taper angle and ITO tail length by SEM. The specific results are shown in Table 2 and Figures 1-10 , wherein, Figures 1-5 are SEM images of the Cu-ITO substrate etched by the Cu-ITO etching solution provided by Examples 1-5, respectively, Figures 6-10 are SEM images of the Cu-ITO substrate etched by the Cu-ITO etching solution provided by Comparative Examples 1-5, respectively.

[0120] Table 2

[0121] Taper angle / ° ITOTail / pm Example 1 44.07 0.1389 Example 2 44.08 0.1091 Example 3 44.72 0.0907 Example 4 45.00 0.1190 Example 5 45.43 0.1276 Comparative Example 1 47.14 0.2012 Comparative Example 2 44.57 0.1885 Comparative Example 3 48.00 0.1701 Comparative Example 4 40.89 0.1587 Comparative Example 5 61.83 0.1332

[0122] According to the data in Table 1 and Table 2, the Cu-ITO etching solution obtained in Examples 1-5 still has excellent and stable etching rate after being placed for 24 hours, and can effectively etch the Cu sample and the ITO sample. Meanwhile, according to the data in Table 2 and Figures 1-10 According to the data in Table 2, the Taper angle of the Cu-ITO substrate etched by the Cu-ITO etching solution obtained in Examples 1-5 is stable between 44-46°, and the ITO Tail parameter is less than 0.15 μm, which meets the requirements of the production process, fully illustrating that the Cu-ITO etching solution of the present application has the excellent characteristics of long service life and stable etching performance.

[0123] According to the comparison between Comparative Example 1 and Comparative Example 1, the sulfonic acid derivative 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid used in the present application can not only effectively etch the ITO layer and destroy the stability of the ITO crystal, but also is beneficial to maintaining the etching stability of the etching solution, compared with 4-aminobenzenesulfonic acid.

[0124] According to the comparison between Comparative Example 1 and Comparative Example 2, the organic weak oxidizing agent nicotinamide-N-oxide used in the present application is more helpful to prevent the change of the properties of the etching solution and increase the stability of the etching composition, compared with N-methylmorpholine-N-oxide, so that the etching solution maintains stable etching rate.

[0125] According to the comparison between Comparative Example 1 and Comparative Examples 3 and 4, the sulfonic acid derivative and the organic weak oxidizing agent are added into the etching solution according to the specific mass ratio, and the two components interact and synergize, so that the etching solution can maintain good etching ability for a long time.

[0126] According to the comparison between Comparative Example 1 and Comparative Example 5, the etching solution of the present application does not include nitric acid and hydrogen fluoride, and is composed of hydrogen peroxide, a sulfonic acid derivative, an organic weak oxidizing agent, a corrosion inhibitor, a hydrogen peroxide stabilizer and a surfactant. The components interact with each other, so that the etching solution can etch the Cu-ITO substrate in one step, has stable etching rate, is green and environmentally friendly, and has small pollution.

[0127] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0128] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A Cu-ITO etching liquid, characterized by, According to the mass percentage, the following components are included: hydrogen peroxide 8-18%, sulfonic acid derivative 3-6%, organic weak oxidizing agent 0.5-1.5%, corrosion inhibitor 0.1-2%, hydrogen peroxide stabilizer 0.05-1%, surfactant 1-3%, and the balance is water; The sulfonic acid derivative is 4,4'-((4-sulfophenyl) aza diyl) bis(methylene) benzene dicarboxylic acid; The organic weak oxidizing agent is nicotinamide-N-oxide; The mass ratio of the sulfonic acid derivative to the organic weak oxidizing agent is (4-6):

1. 2.The Cu-ITO etching solution of claim 1, wherein According to the mass percentage, the following components are included: hydrogen peroxide 12-16%, sulfonic acid derivative 4.5-5.5%, organic weak oxidizing agent 0.75-1.25%, corrosion inhibitor 0.5-1.5%, hydrogen peroxide stabilizer 0.1-0.5%, surfactant 1.5-2.5%, and the balance is water. 3.The Cu-ITO etching solution of claim 1, wherein The corrosion inhibitor is at least one of benzotriazole, benzimidazole, benzoquinoline, benzopyridine, benzopyrazine, and benzisoxazole. 4.The Cu-ITO etching solution of claim 1, wherein The hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenyl urea and / or 3-aminopropyl phosphonic acid.

5. The Cu-ITO etching solution of claim 1, wherein, The surfactant is at least one of alkyl phenol polyoxyethylene ether, polyethylene glycol, polyether modified polysiloxane, fatty alcohol polyoxyethylene ether, and fatty acid polyoxyethylene ether.

6. according to the preparation method of the Cu-ITO etching solution described in any one of claim 1-5, it is characterized in that, The following steps are included: S1. According to the Cu-ITO etching liquid formula, hydrogen peroxide, sulfonic acid derivative, organic weak oxidizing agent, corrosion inhibitor, hydrogen peroxide stabilizer, surfactant, and water are weighed; S2. The sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer, and water are stirred at room temperature until all the materials are completely dissolved to prepare a mixed solution; S3. The surfactant is added to the mixed solution obtained in step S2, stirred at room temperature, and then returned to room temperature. Hydrogen peroxide and organic weak oxidizing agent are added and stirred at room temperature until all the materials are uniformly mixed to obtain a Cu-ITO etching liquid.

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