Micro-etching coarsening liquid for circuit board and preparation method of micro-etching coarsening liquid

Abstract

The invention relates to the technical field of printed circuit board production, in particular to micro-etching coarsening liquid for a circuit board and a preparation method of the micro-etching coarsening liquid. The micro-etching coarsening liquid for the circuit board comprises the following preparation raw materials by mass concentration: 60-70 mL / L of concentrated sulfuric acid, 130-140 mL / L of hydrogen peroxide, 12-15 g / L of polyethylene glycol, 3-5 g / L of propoxylated propargyl alcohol, 2-4 g / L of a complexing agent, 3-6 g / L of a corrosion inhibitor, 3-5 g / L of a stabilizer, 5-8 g / L of a surfactant and 6-8 g / L of an accelerant. The micro-etching coarsening liquid for the circuit board has the advantages of high etching rate, excellent stability, high copper ion containing capacity and good oxidation resistance, and is suitable for micro-etching treatment of the circuit board.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit board production, and in particular to a micro-etching and roughening liquid for a circuit board and a preparation method thereof. Background Art

[0002] Printed Circuit Board (FPC) is an electronic component that supports electronic components and provides electrical connections. It is light, consistent, small, reliable, and easy to standardize. It has been widely used in digital products, aerospace, smart home appliances, communications, medical and other high-tech electronic products. As a basic component of electronic products, the performance of printed circuit boards plays a vital role in the service life of electronic products. In recent years, with the development of electronic products towards multifunctionality, miniaturization, high density, and high efficiency, higher requirements have been put forward for the refinement of the preparation and application reliability of printed circuit boards.

[0003] At present, printed circuit boards are usually prepared by multi-process processing with copper clad laminate as the substrate. Among them, micro-etching roughening treatment is an important processing step in the preparation of printed circuit boards, which is the key to realizing the preparation of refined circuit boards and improving the quality of refined circuit boards. The use of micro-etching roughening liquid to micro-etch the copper surface can form a microscopic rough structure on the surface of the copper layer, enhancing the adhesion between the bonding layer and the copper layer.

[0004] In order to achieve the ideal micro-etching effect, the performance requirements for the micro-etching roughening liquid are relatively high. At present, the composite system of sulfuric acid + hydrogen peroxide + surfactant is still the mainstream micro-etching system due to its high micro-etching efficiency and convenient waste liquid recovery. Although the conventional micro-etching roughening system can achieve a certain micro-etching roughening effect, various problems are gradually exposed during actual use. For example, the roughness and uniformity of the copper surface are difficult to be effectively controlled, which easily leads to short-circuit failures on the circuit board; the system's processing capacity is low, and the tank liquid needs to be frequently replaced after reaching the copper ion holding capacity, resulting in a waste of resources; in addition, the surfactant components commonly used in the existing micro-etching system can achieve basic cleaning of the copper surface, but the removal effect of pollutants with strong adsorption capacity on the copper surface is not good, and the polishing and protection effects are insufficient, which easily causes oxidation or discoloration of the copper surface, causing the micro-etching device to fail due to primary battery corrosion, which greatly affects the normal use of the circuit board. Summary of the invention

[0005] The purpose of the present application is to provide a micro-etching roughening liquid for circuit boards and a preparation method thereof in view of the deficiencies in the current technology. The micro-etching roughening liquid for circuit boards of the present application has excellent stability while having a high etching rate, and can inhibit the oxidation and discoloration of the copper surface; and has a strong capacity for accommodating copper ions, small fluctuations in the micro-etching rate during the action, and the roughness of the copper surface after micro-etching is uniform, and is suitable for micro-etching treatment of circuit boards.

[0006] In a first aspect, the present application provides a micro-etching and roughening liquid for a circuit board, which adopts the following technical solution: A micro-etching and roughening liquid for a circuit board comprises the following raw materials, measured by mass concentration: 60-70 mL / L of concentrated sulfuric acid, 130-140 mL / L of hydrogen peroxide, 12-15 g / L of polyethylene glycol, 3-5 g / L of propoxylated propynyl alcohol, 2-4 g / L of a complexing agent, 3-6 g / L of a corrosion inhibitor, 3-5 g / L of a stabilizer, 5-8 g / L of a surfactant, and 6-8 g / L of an accelerator.

[0007] By adopting the above technical solution, concentrated sulfuric acid: as a strong acid, concentrated sulfuric acid plays a major etching role in the micro-etching process. It can react with copper to generate soluble copper sulfate, thereby achieving etching of the copper surface. Hydrogen peroxide: hydrogen peroxide acts as an oxidant in the micro-etching process, which can accelerate the oxidation reaction of copper and increase the etching rate. At the same time, hydrogen peroxide can also react with concentrated sulfuric acid to generate sulfuric acid and water to maintain the acidic environment of the solution. Polyethylene glycol: polyethylene glycol is a non-ionic surfactant that can form a protective film on the copper surface and reduce the oxidation discoloration of the copper surface. At the same time, polyethylene glycol can also reduce the surface tension of the solution, which is conducive to the wetting and spreading of the solution on the copper surface. Propoxylated propargyl alcohol: propoxylated propargyl alcohol is a compound with antioxidant properties, which can work together with polyethylene glycol to improve the antioxidant properties of the copper surface after micro-etching. Complexing agent: the complexing agent can form a complex with the metal ions in the solution, thereby inhibiting the precipitation and crystallization of copper ions and maintaining the stability of the solution. Corrosion inhibitor: Corrosion inhibitor can slow down the etching rate of copper, making the micro-etching process more uniform. Stabilizer: Stabilizer can maintain the stability of the solution and prevent the precipitation of particles in the solution. In the present application, modified polyacrylonitrile, as a polymer material, may play the role of stabilizer and dispersant. Surfactant: Surfactant can reduce the surface tension of the solution, which is beneficial to the wetting and spreading of the solution on the copper surface. Promoter: Promoter can accelerate the micro-etching reaction and increase the etching rate. In summary, the micro-etching roughening solution for circuit boards of the present application achieves the characteristics of high-efficiency etching rate, excellent stability, inhibition of copper surface oxidation and discoloration, and strong copper ion accommodation capacity through the synergistic effect of various components. The micro-etching rate fluctuates little during the action, and the roughness of the copper surface after micro-etching is uniform, which is suitable for micro-etching treatment of circuit boards.

[0008] Preferably, the stabilizer is composed of ethylenediaminetetraacetic acid, ethylenediamine disuccinic acid and modified polyacrylonitrile in a mass ratio of 5:4:5.

[0009] By adopting the above technical solutions, ethylenediaminetetraacetic acid (EDTA): EDTA is a strong chelating agent that can form stable complexes with metal ions, thereby preventing the free movement and precipitation of metal ions in the solution. This helps to maintain the stability of the solution and reduce the interference of metal ions with the etching process. It works together with EDDS and MPAN to enhance the overall stability and dispersibility of the solution. Ethylenediamine disuccinic acid (EDDS): EDDS is also a chelating agent, but its structure is slightly different from EDTA and may provide additional stability or selective chelation under certain conditions. It can help control the concentration of metal ions in the solution and further reduce the risk of uneven etching. Combined with EDTA and MPAN, a more comprehensive metal ion control system is formed to improve the overall performance of the solution. Modified polyacrylonitrile (MPAN): As a polymer material, MPAN acts as a stabilizer and dispersant in the solution. It can help stabilize the particles in the solution, prevent precipitation, and has a certain protective effect on the copper surface, reducing the unevenness during the etching process. Working together with EDTA and EDDS, the stability and dispersibility of the solution are enhanced through physical and chemical dual mechanisms, while providing additional protection for the copper surface and reducing side effects during the etching process. In summary, this stabilizer combination consisting of EDTA, EDDS and MPAN plays a key role in the micro-etching roughening solution for circuit boards of this application. Through synergistic effects, they not only improve the stability and dispersibility of the solution, but also enhance the protection of the copper surface, reduce the unevenness and side effects during the etching process, and thus improve the performance and reliability of the circuit board.

[0010] Preferably, the preparation method of the modified polyacrylonitrile is: heat-treating 20 parts of polyacrylonitrile powder at 245°C for 5 hours in an air atmosphere, then cooling to room temperature, and then immersing in 80 parts of a 25wt% diethylenetriamine aqueous solution for 4 hours, washing with deionized water after immersion, and then drying at 90°C for 12 hours to obtain modified polyacrylonitrile.

[0011] By adopting the above technical scheme, first, 20 parts of polyacrylonitrile powder are heat-treated at 245°C in an air atmosphere for 5 hours. The purpose of this step is to change the surface properties of polyacrylonitrile through a thermal oxidation process, introduce some polar groups such as carboxyl or cyano groups, thereby increasing its compatibility and reactivity with aqueous solutions. The heat-treated polyacrylonitrile is cooled to room temperature and then immersed in 80 parts of a 25wt% diethylenetriamine aqueous solution for 4 hours. Diethylenetriamine is a polyamine compound that can react chemically with the polar groups on the surface of polyacrylonitrile to form a cross-linked structure, thereby enhancing the mechanical strength and chemical resistance of the material. After the immersion treatment, it is thoroughly washed with deionized water to remove excess diethylenetriamine and other impurities, and then dried at 90°C for 12 hours to obtain the final modified polyacrylonitrile product. The prepared modified polyacrylonitrile can act as a stabilizer in the solution due to its cross-linked structure and polar groups, helping to maintain the uniformity and stability of the micro-etching roughening solution and prevent particle precipitation. It can also act as a dispersant to ensure that other components in the solution, such as complexing agents and corrosion inhibitors, are evenly distributed, thereby improving the consistency and efficiency of the micro-etching process. Modified polyacrylonitrile has a certain protective effect on the copper surface, which can reduce the unevenness in the etching process and avoid the degradation of circuit board performance caused by over-etching. By complexing with impurity ions, modified polyacrylonitrile helps to inhibit the Galvani effect, an electrochemical phenomenon that causes localized corrosion on metal surfaces. This helps to make the micro-etching process easier to control and maintain a moderate roughness on the surface of the circuit board. In summary, the use of modified polyacrylonitrile in micro-etching roughening solution for circuit boards not only improves the stability and dispersibility of the solution, but also enhances the protective effect on the copper surface, reduces unnecessary side reactions, and makes the entire micro-etching process more efficient and controllable.

[0012] Preferably, the corrosion inhibitor consists of 1-hydroxybenzotriazole, dibenzotriazole and modified polyacrylamide in a mass ratio of 3:3:5.

[0013] By adopting the above technical scheme, this combination of corrosion inhibitors plays a key role in the micro-etching roughening solution for circuit boards, which is specifically manifested in the following aspects: 1. Inhibiting the oxidation and discoloration of the copper surface: 1-hydroxybenzotriazole and dibenzotriazole are both effective copper corrosion inhibitors. They can form a protective film on the copper surface to prevent copper from being oxidized and discolored during the etching process. This helps to maintain the appearance quality and electrical properties of the circuit board. 2. Improving solution stability: The modified polyacrylamide is made by grafting 4-methyl-5-imidazolecarbonyl chloride, in which the amide group and imidazole group can complex with impurity ions, thereby inhibiting the Galvani effect (an electrochemical phenomenon that causes uneven corrosion on the metal surface). This effect helps to make the micro-etching process easier to control, avoid excessive etching of the circuit board, and ensure that the roughness of the circuit board surface is moderate. 3. Synergistic enhancement effect: When 1-hydroxybenzotriazole, dibenzotriazole and modified polyacrylamide are used in combination at a mass ratio of 3:3:5, there is a synergistic effect between them. This synergistic effect not only enhances the corrosion inhibition effect of each, but also improves the stability and efficiency of the entire micro-etching roughening liquid system. For example, 1-hydroxybenzotriazole and dibenzotriazole may form a denser protective layer on the copper surface, while modified polyacrylamide helps stabilize this protective layer to prevent it from being destroyed. 4. Improve the antioxidant properties of the copper surface after micro-etching: The presence of polyethylene glycol and propoxylated propynyl alcohol further improves the antioxidant properties of the copper surface after micro-etching. These ingredients can form an additional protective film on the copper surface, working together with the aforementioned corrosion inhibitors to provide more comprehensive protection. In summary, this specific ratio of corrosion inhibitor combination can not only effectively inhibit the oxidation discoloration of the copper surface, but also improve the stability and controllability of the micro-etching roughening liquid, so that the roughness of the copper surface after micro-etching is uniform, thereby meeting the requirements of micro-etching treatment of circuit boards.

[0014] Preferably, the preparation method of the modified polyacrylamide comprises the following steps: S51, 40g 4-methyl-5-imidazolecarboxylic acid, 68g dichloromethane and 0.4g N,N-dimethylformamide were added into a container, the temperature was adjusted to 3°C, 45g oxalyl chloride was added into the reaction solution under stirring, the reaction was continued for 6h, the temperature was raised to 23°C, the reaction was continued for 20h, and finally heptane was continuously added until no solid precipitate was precipitated, and 46.3g 4-methyl-5-imidazolecarboxylic acid chloride was obtained after filtration, washing and drying; S52, preparing a 0.8 wt % polyacrylamide solution by mixing polyacrylamide and an ethanol solution having a mass concentration of 50%; S53, add 4g of 4-methyl-5-imidazolecarbonyl chloride and 0.05g of triethylamine to 416g of polyacrylamide solution, react at 83°C for 7h, and finally remove the solvent by reduced pressure distillation. After crystallization, filtration, washing and drying, modified polyacrylamide is obtained.

[0015] By adopting the above technical scheme, the prepared modified polyacrylamide is grafted with polyacrylamide to introduce imidazole groups. The imidazole group has good coordination ability and can form a stable complex with copper ions, reduce the concentration of free copper ions, thereby inhibiting the Galvani effect and preventing over-etching. The structure of the polymer chain is provided, so that the imidazole group is evenly distributed in the solution, enhancing the overall corrosion inhibition effect. The imidazole group in the modified polyacrylamide can not only complex with copper ions, but also form a complex with other metal ions (such as nickel, etc.), reducing the influence of these impurity ions on the etching process, and improving the stability of the solution and the uniformity of etching. As a polymer material, the modified polyacrylamide can play a role in thickening and stabilization in the solution, help maintain the uniformity of the solution, and prevent precipitation and stratification. The grafted polyacrylamide may have a certain surface activity, which helps to improve the wettability and coverage of the solution, making the etching process more uniform. The protective film formed by the modified polyacrylamide on the copper surface can reduce the oxidation discoloration of the copper surface. At the same time, due to its good corrosion inhibition performance, the roughness of the copper surface can be kept uniform, avoiding excessive surface roughness caused by excessive etching. Since modified polyacrylamide can effectively complex impurity ions and stabilize the solution, the release and dissolution of copper ions during microetching is more stable, thereby improving the stability of the microetching rate and reducing fluctuations. Polyethylene glycol and propoxylated propargyl alcohol are mainly responsible for forming a protective film on the copper surface and improving the antioxidant properties. Modified polyacrylamide further enhances this protective effect through corrosion inhibition and complexation, ensuring that the copper surface has good antioxidant properties and uniform roughness after microetching. Modified polyacrylamide works together with other additives to form a stable microetching system, ensuring that the etching process is efficient, stable and controllable. In summary, modified polyacrylamide not only has corrosion inhibition and complexation in the microetching roughening solution, but also can act as a stabilizer and dispersant to protect the copper surface, improve the stability of the microetching rate, and synergize with other additives to ensure excellent microetching treatment of the circuit board.

[0016] Preferably, the surfactant is composed of isomeric tridecyl alcohol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether in a mass ratio of 1:1.

[0017] By adopting the above technical scheme, the role of the surfactant in the micro-etching roughening liquid for circuit boards is mainly to reduce the surface tension of the liquid and improve the wettability and permeability of the liquid. The surfactant composed of isotridecyl alcohol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether in a mass fraction ratio of 1:1 can give full play to the advantages of both and improve the performance of the micro-etching roughening liquid. Isotridecyl alcohol polyoxyethylene ether is a non-ionic surfactant with good wettability and permeability, which can reduce the surface tension of the liquid and make the liquid easier to spread on the copper surface, thereby improving the etching effect of the micro-etching roughening liquid. In addition, isotridecyl alcohol polyoxyethylene ether also has a certain corrosion inhibition effect, which can slow down the oxidation discoloration of the copper surface. Isooctyl alcohol polyoxypropylene polyoxyethylene ether is also a non-ionic surfactant with good wettability and permeability, which can reduce the surface tension of the liquid and make the liquid easier to spread on the copper surface. Compared with isotridecyl alcohol polyoxyethylene ether, isooctyl alcohol polyoxypropylene polyoxyethylene ether has better stability and salt resistance, and can maintain stable activity under higher temperature and salinity conditions. When isomeric tridecanol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether are used as surfactants in a mass ratio of 1:1, a synergistic effect can be produced between the two to further improve the performance of the micro-etching roughening solution. On the one hand, the mixture of the two can improve the wettability and permeability of the liquid, making it easier for the micro-etching roughening solution to spread on the copper surface; on the other hand, the mixture of the two can slow down the oxidation discoloration of the copper surface and improve the stability of the micro-etching roughening solution. Therefore, this surfactant combination has a good effect on the micro-etching treatment of circuit boards.

[0018] Preferably, the accelerator is 2-mercapto-1-methylimidazole.

[0019] Preferably, the complexing agent is hydroxyethylethylenediaminetriacetic acid.

[0020] Preferably, the mass concentration of the concentrated sulfuric acid is 98%, the mass concentration of the hydrogen peroxide is 30%, and the polyethylene glycol is polyethylene glycol 800.

[0021] In the second aspect, the present application provides a method for preparing a micro-etching roughening liquid for a circuit board, adopting the following technical scheme: As a general technical concept, the present application also provides a method for preparing the above-mentioned micro-etching roughening liquid for a circuit board, comprising the following steps: 60-70mL of concentrated sulfuric acid, 130-140mL of hydrogen peroxide, 12-15g of polyethylene glycol, 3-5g of propoxylated propynyl alcohol, 2-4g of a complexing agent, 3-6g of a corrosion inhibitor, 3-5g / L of a stabilizer, 5-8g of a surfactant and 6-8g of a promoter are added to an appropriate amount of deionized water and mixed evenly, and then the mixed solution is diluted to 1L to obtain a micro-etching roughening liquid for a circuit board.

[0022] In summary, the beneficial technical effects of this application are: 1. High Efficiency Etching Rate: The addition of concentrated sulfuric acid and hydrogen peroxide makes the micro-etching roughening solution have a higher etching rate, which can quickly remove oxides and other impurities on the copper surface.

[0023] 2. Excellent stability: By adding stabilizers, surfactants and other ingredients, the micro-etching and roughening liquid remains stable during long-term use and is not prone to precipitation or decomposition.

[0024] 3. Inhibit oxidation and discoloration of copper surface: The combined effect of polyethylene glycol and propoxylated propynyl alcohol can form a protective film on the copper surface, effectively preventing oxidation and discoloration of the copper surface during micro-etching.

[0025] 4. Strong copper ion accommodating capacity: The addition of complexing agent and corrosion inhibitor makes the micro-etching roughening solution have a strong copper ion accommodating capacity, which can maintain the stability of the micro-etching rate during the micro-etching process and avoid the fluctuation of the micro-etching rate caused by the change of copper ion concentration.

[0026] 5. The roughness of the copper surface is uniform after micro-etching: The addition of modified polyacrylonitrile and modified polyacrylamide can improve the antioxidant properties of the copper surface after micro-etching, while reducing the unevenness during the etching process, making the roughness of the copper surface after micro-etching more uniform.

[0027] 6. Easy to control the micro-etching process: The amide group and imidazole in the modified polyacrylamide can inhibit corrosion and can also complex with impurity ions to inhibit the Giovanni effect, making the micro-etching process easier to control and avoiding excessive corrosion of the circuit board. DETAILED DESCRIPTION

[0028] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0029] In the following examples and preparation examples, 1 part means 100 g, the mass concentration of concentrated sulfuric acid is 98%, the mass concentration of hydrogen peroxide is 30%, and the polyethylene glycol is polyethylene glycol 800.

[0030] Preparation Example 1 Preparation of modified polyacrylonitrile The preparation method of modified polyacrylonitrile is as follows: 20 parts of polyacrylonitrile powder are heat-treated at 245°C for 5 hours in an air atmosphere, then cooled to room temperature, and then immersed in 80 parts of a 25wt% diethylenetriamine aqueous solution for 4 hours, and then washed with deionized water after immersion, and then dried at 90°C for 12 hours to obtain modified polyacrylonitrile.

[0031] Preparation Example 2 Preparation of modified polyacrylamide The preparation method of modified polyacrylamide comprises the following steps: S51, 40g 4-methyl-5-imidazolecarboxylic acid, 68g dichloromethane and 0.4g N,N-dimethylformamide were added into a container, the temperature was adjusted to 3°C, 45g oxalyl chloride was added into the reaction solution under stirring, the reaction was continued for 6h, the temperature was raised to 23°C, the reaction was continued for 20h, and finally heptane was continuously added until no solid precipitate was precipitated, and 46.3g 4-methyl-5-imidazolecarboxylic acid chloride was obtained after filtration, washing and drying; S52, preparing a 0.8 wt % polyacrylamide solution by mixing polyacrylamide and an ethanol solution having a mass concentration of 50%; S53, add 4g of 4-methyl-5-imidazolecarbonyl chloride and 0.05g of triethylamine to 416g of polyacrylamide solution, react at 83°C for 7h, and finally remove the solvent by reduced pressure distillation. After crystallization, filtration, washing and drying, modified polyacrylamide is obtained.

[0032] Example 1 A micro-etching roughening liquid for a circuit board, comprising the following raw materials, measured by mass concentration: 60 mL / L concentrated sulfuric acid, 130 mL / L hydrogen peroxide, 12 g / L polyethylene glycol, 3 g / L propoxylated propargyl alcohol, 2 g / L hydroxyethylethylenediaminetriacetic acid, 3 g / L corrosion inhibitor, 3 g / L stabilizer, 5 g / L surfactant, and 6 g / L 2-mercapto-1-methylimidazole, wherein the stabilizer is composed of ethylenediaminetetraacetic acid, ethylenediaminedisuccinic acid and modified polyacrylonitrile in a mass ratio of 5:4:5, the corrosion inhibitor is composed of 1-hydroxybenzotriazole, dibenzotriazole and modified polyacrylamide in a mass ratio of 3:3:5, and the surfactant is composed of isomeric tridecanol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether in a mass ratio of 1:1; The preparation method of the above-mentioned micro-etching roughening liquid for circuit boards comprises the following steps: adding 60 mL of concentrated sulfuric acid, 130 mL of hydrogen peroxide, 12 g of polyethylene glycol, 3 g of propoxylated propargyl alcohol, 2 g of hydroxyethylethylenediaminetriacetic acid, 3 g of corrosion inhibitor, 3 g / L of stabilizer, 5 g of surfactant and 6 g of 2-mercapto-1-methylimidazole to an appropriate amount of deionized water and mixing evenly, and then adjusting the mixed solution to 1 L to obtain a micro-etching roughening liquid for circuit boards.

[0033] Example 2 A micro-etching roughening liquid for a circuit board, comprising the following raw materials, measured by mass concentration: 70 mL / L concentrated sulfuric acid, 140 mL / L hydrogen peroxide, 15 g / L polyethylene glycol, 5 g / L propoxylated propargyl alcohol, 4 g / L hydroxyethylethylenediaminetriacetic acid, 6 g / L corrosion inhibitor, 5 g / L stabilizer, 8 g / L surfactant, and 8 g / L 2-mercapto-1-methylimidazole, wherein the stabilizer is composed of ethylenediaminetetraacetic acid, ethylenediamine disuccinic acid and modified polyacrylonitrile in a mass ratio of 5:4:5, the corrosion inhibitor is composed of 1-hydroxybenzotriazole, dibenzotriazole and modified polyacrylamide in a mass ratio of 3:3:5, and the surfactant is composed of isomeric tridecanol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether in a mass ratio of 1:1; The preparation method of the above-mentioned micro-etching roughening liquid for circuit boards comprises the following steps: adding 70 mL of concentrated sulfuric acid, 140 mL of hydrogen peroxide, 15 g of polyethylene glycol, 5 g of propoxylated propargyl alcohol, 4 g of hydroxyethylethylenediaminetriacetic acid, 6 g of corrosion inhibitor, 5 g / L of stabilizer, 8 g of surfactant and 8 g of 2-mercapto-1-methylimidazole to an appropriate amount of deionized water and mixing them evenly, and then adjusting the mixed solution to 1 L to obtain a micro-etching roughening liquid for circuit boards.

[0034] Example 3 A micro-etching roughening liquid for a circuit board, comprising the following raw materials by mass concentration: 65 mL / L concentrated sulfuric acid, 135 mL / L hydrogen peroxide, 14 g / L polyethylene glycol, 4 g / L propoxylated propargyl alcohol, 3 g / L hydroxyethylethylenediaminetriacetic acid, 4 g / L corrosion inhibitor, 4 g / L stabilizer, 7 g / L surfactant, and 7 g / L 2-mercapto-1-methylimidazole, wherein the stabilizer is composed of ethylenediaminetetraacetic acid, ethylenediamine disuccinic acid and modified polyacrylonitrile in a mass ratio of 5:4:5, the corrosion inhibitor is composed of 1-hydroxybenzotriazole, dibenzotriazole and modified polyacrylamide in a mass ratio of 3:3:5, and the surfactant is composed of isomeric tridecanol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether in a mass ratio of 1:1; The preparation method of the above-mentioned micro-etching roughening liquid for circuit boards comprises the following steps: adding 65 mL of concentrated sulfuric acid, 135 mL of hydrogen peroxide, 14 g of polyethylene glycol, 4 g of propoxylated propargyl alcohol, 3 g of hydroxyethylethylenediaminetriacetic acid, 4 g of corrosion inhibitor, 4 g / L of stabilizer, 7 g of surfactant and 7 g of 2-mercapto-1-methylimidazole to an appropriate amount of deionized water and mixing evenly, and then adjusting the mixed solution to 1 L to obtain a micro-etching roughening liquid for circuit boards.

[0035] Comparative Example 1 The same as Example 3, except that the stabilizer is ethylenediaminetetraacetic acid.

[0036] Comparative Example 2 The same as Example 3, except that the stabilizer is ethylenediamine disuccinic acid.

[0037] Comparative Example 3 The same as Example 3, except that the stabilizer is modified polyacrylonitrile.

[0038] Comparative Example 4 The same as Example 3, except that the corrosion inhibitor is 1-hydroxybenzotriazole.

[0039] Comparative Example 5 The same as Example 3, except that the corrosion inhibitor is dibenzotriazole.

[0040] Comparative Example 6 The same as Example 3, except that the corrosion inhibitor is modified polyacrylamide.

[0041] Comparative Example 7 The same as Example 3, except that the surfactant is isomeric tridecanol polyoxyethylene ether.

[0042] Comparative Example 8 The same as Example 3, except that the surfactant is isooctyl alcohol polyoxypropylene polyoxyethylene ether.

[0043] Performance Testing The micro-etching roughening liquids for circuit boards prepared in Examples 1 to 3 and Comparative Examples 1 to 8 were respectively subjected to the following performance tests. The test results are shown in Table 1.

[0044] 1. Micro-etching rate determination: The micro-etching roughening liquid provided in Examples 1 to 3 and Comparative Examples 1 to 8 was respectively added to a spray machine, and then 11 copper-clad substrates (10 cm × 10 cm) were taken respectively. The copper-clad substrates were pickled with an aqueous solution of sulfuric acid with a mass concentration of 30 wt%, and the surface was cleaned by washing with water, and then tested under spraying conditions. After the spraying, they were washed with deionized water, and the masses of the copper-clad substrates before and after the spraying were recorded as m1 and m2 after drying, and the micro-etching rate was calculated. During the spraying process, the temperature of the micro-etching roughening liquid for high-frequency high-speed circuit boards was 30 ° C, and the spraying pressure was 1 kg / cm 2 , the spraying time is 1 minute; the calculation formula of the micro-etching rate is as follows.

[0045] Microetching rate = (m1-m2) / (S×ρ)×10000; Where m1 and m2 are the mass of the copper clad laminate before and after the micro-etching treatment with the micro-etching roughening liquid spray for high-frequency high-speed circuit boards (in g); S is the area of ​​the copper clad laminate (S = 10 × 10 × 2 = 200 cm 2 ), ρ is the density of copper, which is 8.96 g / cm3; 2. Roughness: The surface roughness Ra value of the copper-clad substrate treated with micro-etching roughening liquid for high-frequency and high-speed circuit boards is obtained through 3D laser microscope testing; 3. Appearance and pits: Then take out the sample and dry it, compare whether the surface of the board is evenly matte, and observe whether there are pits in the blind hole under a microscope; 4. Storage stability: Place different micro-etching solutions in a 35°C water bath for 90 days, and measure the persulfate content in the solution. The storage stability N (%) is calculated as follows: N = W1 × 100% / W2, where: W1 is the initial content of persulfate in the micro-etching roughening solution (g / L), and W2 is the content of persulfate in the micro-etching roughening solution after being placed in a 35°C water bath for 60 days (g / L).

[0046] Table 1 Performance test Analyzing the data in Table 1, we can see that: 1) The micro-etching roughening solution for circuit boards prepared in Examples 1 to 3 has excellent stability while having a high etching rate. The copper surface obtained by the treatment of this application is uniformly micro-etched and can effectively prevent the copper surface from being oxidized for a long time. The roughness of the copper surface after micro-etching is uniform, and it is suitable for micro-etching treatment of circuit boards.

[0047] 2) The performance comparison analysis of the micro-etching roughening solution for circuit boards prepared in combination with Example 3 and Comparative Examples 1 to Comparative Examples 3 shows that the stabilizer is composed of ethylenediaminetetraacetic acid, ethylenediamine disuccinic acid and modified polyacrylonitrile in a mass ratio of 5:4:5. The synergistic effect between them is utilized to jointly maintain the stability of the micro-etching solution and the uniformity of the etching effect, thereby achieving efficient and stable micro-etching treatment.

[0048] 3) The performance comparison analysis of the micro-etching roughening solution for circuit boards prepared in combination with Example 3 and Comparative Examples 4 to 6 shows that the corrosion inhibitor is composed of 1-hydroxybenzotriazole, dibenzotriazole and modified polyacrylamide in a mass ratio of 3:3:5. The synergistic effect between them can not only effectively inhibit the oxidation discoloration of the copper surface, but also improve the stability and controllability of the micro-etching roughening solution, so that the roughness of the copper surface after micro-etching is uniform, thereby meeting the requirements of micro-etching treatment of circuit boards.

[0049] 4) The performance comparison analysis of the micro-etching roughening liquid for circuit boards prepared in combination with Example 3 and Comparative Examples 7-8 shows that the surfactant is composed of isomeric tridecanol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether in a mass ratio of 1:1. They improve the wettability of the copper surface by reducing the surface tension of the liquid, ensuring that other chemical components can contact the copper surface more evenly and effectively. The synergistic effect between them is utilized to enhance the overall performance of the micro-etching treatment liquid. On the one hand, the mixture of the two can improve the wettability and permeability of the liquid, making it easier for the micro-etching roughening liquid to spread on the copper surface; on the other hand, the mixture of the two can slow down the oxidation discoloration of the copper surface and improve the stability of the micro-etching roughening liquid.

[0050] The above embodiments are only used to explain the technical solutions of the present application rather than to limit them. Although the above embodiments provide a specific description of the present application, relevant technical personnel should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modifications and equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the present application.

Claims

1. A micro-etching and roughening liquid for a circuit board, characterized in that: Calculated by mass concentration, the preparation raw materials include: concentrated sulfuric acid 60-70 mL / L, hydrogen peroxide 130-140 mL / L, polyethylene glycol 12-15 g / L, propoxylated propynyl alcohol 3-5 g / L, complexing agent 2-4 g / L, corrosion inhibitor 3-6 g / L, stabilizer 3-5 g / L, surfactant 5-8 g / L, and accelerator 6-8 g / L.

2. A micro-etching and roughening liquid for a circuit board according to claim 1, characterized in that: The stabilizer is composed of ethylenediaminetetraacetic acid, ethylenediamine disuccinic acid and modified polyacrylonitrile in a mass ratio of 5:4:

5.

3. A micro-etching and roughening liquid for a circuit board according to claim 2, characterized in that: The preparation method of the modified polyacrylonitrile is as follows: 20 parts of polyacrylonitrile powder are heat-treated at 245° C. for 5 hours in an air atmosphere, then cooled to room temperature, and then immersed in 80 parts of a 25wt% diethylenetriamine aqueous solution for 4 hours, washed with deionized water after immersion, and then dried at 90° C. for 12 hours to obtain the modified polyacrylonitrile.

4. The micro-etching and roughening liquid for a circuit board according to claim 1, characterized in that: The corrosion inhibitor consists of 1-hydroxybenzotriazole, dibenzotriazole and modified polyacrylamide in a mass ratio of 3:3:

5.

5. A micro-etching and roughening liquid for a circuit board according to claim 4, characterized in that: The preparation method of the modified polyacrylamide comprises the following steps: S51, 40g 4-methyl-5-imidazolecarboxylic acid, 68g dichloromethane and 0.4g N,N-dimethylformamide were added into a container, the temperature was adjusted to 3°C, 45g oxalyl chloride was added into the reaction solution under stirring, the reaction was continued for 6h, the temperature was raised to 23°C, the reaction was continued for 20h, and finally heptane was continuously added until no solid precipitate was precipitated, and 46.3g 4-methyl-5-imidazolecarboxylic acid chloride was obtained after filtration, washing and drying; S52, preparing a 0.8 wt % polyacrylamide solution by mixing polyacrylamide and an ethanol solution having a mass concentration of 50%; S53, add 4g of 4-methyl-5-imidazolecarbonyl chloride and 0.05g of triethylamine to 416g of polyacrylamide solution, react at 83°C for 7h, and finally remove the solvent by reduced pressure distillation. After crystallization, filtration, washing and drying, modified polyacrylamide is obtained.

6. The micro-etching and roughening liquid for circuit boards according to claim 1, characterized in that: The surfactant is composed of isomeric tridecanol polyoxyethylene ether and isooctyl alcohol polyoxypropylene polyoxyethylene ether in a mass ratio of 1:

1.

7. The micro-etching and roughening liquid for a circuit board according to claim 1, characterized in that: The accelerator is 2-mercapto-1-methylimidazole.

8. The micro-etching and roughening liquid for circuit boards according to claim 1, characterized in that: The complexing agent is hydroxyethylethylenediaminetriacetic acid.

9. The micro-etching and roughening liquid for circuit boards according to claim 1, characterized in that: The mass concentration of the concentrated sulfuric acid is 98%, the mass concentration of the hydrogen peroxide is 30%, and the polyethylene glycol is polyethylene glycol 800.

10. A method for preparing a micro-etching and roughening solution for a circuit board according to any one of claims 1 to 9, characterized in that: include: Add 60-70mL of concentrated sulfuric acid, 130-140mL of hydrogen peroxide, 12-15g of polyethylene glycol, 3-5g of propoxylated propynyl alcohol, 2-4g of complexing agent, 3-6g of corrosion inhibitor, 3-5g / L of stabilizer, 5-8g of surfactant and 6-8g of accelerator to an appropriate amount of deionized water and mix well. Then, dilute the mixed solution to 1L to obtain a micro-etching roughening solution for circuit boards.

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