Etching additive, preparation method thereof, etching solution and application

Abstract

The invention provides an etching additive, a preparation method thereof, an etching solution and application, and relates to the technical field of printed circuit board manufacturing. The etching additive provided by the invention comprises the following components in percentage by mass: 30-60% of an active agent, 20-30% of a stabilizer, 10-20% of a corrosion inhibitor and the balance of a copper complexing agent, the corrosion inhibitor is prepared from at least one of a benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester. By adding at least one of the benzotriazole-polyethylene glycol copolymer and the mercaptobenzothiazole hexadecyl ester as the corrosion inhibitor, excessive corrosion of the copper surface can be inhibited in the etching process, so that the etching uniformity of the copper surface is improved, and meanwhile, the etching rate can be effectively balanced.

Description

Technical Field

[0001] The invention relates to the technical field of printed circuit board manufacturing, and in particular to an etching additive and a preparation method thereof, an etching liquid and applications thereof. Background Art

[0002] Printed circuit boards (PCBs) are an important part of electronic products. With the development of the electronics industry, the production of printed circuit boards has developed rapidly. In the manufacturing process of printed circuit boards, the use of chemical reactions to remove unnecessary copper foil on the circuit board to form a preset conductive circuit pattern is called etching. In order to obtain a fast and stable etching speed, additives are usually added to the etching solution to ensure the uniformity, speed and selectivity of the etching.

[0003] Traditional etching additives mainly include cuprous chloride, ferric chloride, nitric acid and other strong acid substances, and are configured into acidic etching solutions by adding etching additives. Among them, ferric chloride is a more common etching additive, which has good copper dissolving performance and is widely used in the manufacture of double-sided and multi-layer PCB boards. When preparing the acidic etching solution, ferric chloride is dissolved in water in advance, and a surfactant is added to improve the wettability of the etching solution, thereby improving the etching performance.

[0004] However, etching solutions with traditional etching additives often have a slower etching speed, which seriously restricts the production efficiency of PCB boards. In addition, the uniformity of the etching process is difficult to ensure, which leads to a decrease in the accuracy of the circuit pattern and seriously affects the performance and reliability of the final product. Therefore, it is urgent to provide a solution to improve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide an etching additive and a preparation method thereof, an etching solution and applications thereof.

[0006] In a first aspect, the present invention provides an etching additive, which comprises, by mass percentage, 30-60% of an active agent, 20-30% of a stabilizer, 10-20% of a corrosion inhibitor and the remainder of a copper complexing agent; the corrosion inhibitor comprises at least one of a benzotriazole-polyethylene glycol copolymer and hexadecyl mercaptobenzothiazole.

[0007] The etching additive provided by the present invention can suppress excessive corrosion of the copper surface during the etching process by adding at least one of benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester as a corrosion inhibitor, thereby improving the uniformity of etching on the copper surface and effectively balancing the etching rate.

[0008] Optionally, the corrosion inhibitor comprises a benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester in a mass ratio of 1: (0.8-1.2).

[0009] Optionally, the active agent includes at least one of sodium lauryl sulfate, polyoxyethylene fatty acid esters, and sorbitan fatty acid esters.

[0010] Optionally, the stabilizer includes at least one of sodium tripolyphosphate, sodium carboxymethyl cellulose, and thiourea.

[0011] Optionally, the copper complexing agent includes at least one of polyvinyl pyrrolidone and ethylenediaminetetraacetic acid.

[0012] Optionally, the preparation method of the benzotriazole-polyethylene glycol copolymer comprises: copolymerizing benzotriazole and polyethylene glycol diacrylate under the action of an initiator, and then separating, washing and freeze-drying to obtain the benzotriazole-polyethylene glycol copolymer.

[0013] Optionally, the mass ratio of the benzotriazole to the polyethylene glycol diacrylate is (0.1-0.3):1.

[0014] Optionally, the initiator includes at least one of azobisisobutyronitrile, benzoyl peroxide, and dicumyl peroxide.

[0015] Optionally, the mass ratio of the initiator to the reactant is (0.03-0.05):1, and the reactant includes the benzotriazole and the polyethylene glycol diacrylate.

[0016] Optionally, the molecular weight of the polyethylene glycol diacrylate is 200-600.

[0017] Optionally, the benzotriazole and the polyethylene glycol diacrylate are mixed and dissolved in dimethyl sulfoxide to prepare a mixed solution.

[0018] Optionally, after the benzotriazole and the polyethylene glycol diacrylate are mixed, a copolymerization reaction occurs in a non-oxidizing atmosphere at 70-80° C. under the action of an initiator.

[0019] Optionally, the benzotriazole and the polyethylene glycol diacrylate are copolymerized under the action of the initiator for 4-6 hours.

[0020] Optionally, after separation, the sample is rinsed in a cycle with anhydrous ethanol and deionized water and then freeze-dried.

[0021] Optionally, after separation and washing, the product is frozen at -40°C to -50°C, dried once in a vacuum environment at -20°C to -40°C, and then dried twice in a vacuum environment at 20°C to 40°C.

[0022] Optionally, the preparation method of the hexadecyl mercaptobenzothiazole ester comprises: subjecting mercaptobenzothiazole and hexadecyl bromide to nucleophilic substitution under the action of an alkaline catalyst, and then separating and drying to obtain the hexadecyl mercaptobenzothiazole ester.

[0023] Optionally, the mass ratio of the mercaptobenzothiazole to the hexadecyl bromide is 1:(1-3).

[0024] Optionally, the alkaline catalyst includes at least one of pyridine, triethylamine, and 4-dimethylaminopyridine.

[0025] Optionally, the molar ratio of the alkaline catalyst to the hexadecyl bromide is (0.1-0.2):1.

[0026] Optionally, the mercaptobenzothiazole and the hexadecyl bromide are mixed and dissolved in dichloromethane to prepare a mixed solution.

[0027] Optionally, after the mercaptobenzothiazole and the hexadecyl bromide are mixed, they are reacted at 20-30° C. for 12-24 hours under the action of an alkaline catalyst.

[0028] In a second aspect, the present invention also provides a method for preparing any of the above optional etching additives, comprising the following steps: ball-milling and blending an activator, a stabilizer, a corrosion inhibitor and a copper complexing agent to obtain an etching additive.

[0029] In a third aspect, the present invention further provides an etching solution comprising any of the above-mentioned optional etching additives.

[0030] In a fourth aspect, the present invention also provides an application of an etching solution in the manufacture of printed circuit boards. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs.

[0032] The present invention provides an etching additive, which comprises 30-60% of an active agent, 20-30% of a stabilizer, 10-20% of a corrosion inhibitor and the remainder of a copper complexing agent in terms of mass percentage. When performing etching operations, the active agent can accelerate the dissolution of copper, thereby effectively increasing the etching speed, while the stabilizer can improve the stability of the etching solution after adding the etching additive, prevent the etching solution from decomposing and failing during storage and use, and help form a stable chemical environment in the etching solution. In addition, the corrosion inhibitor can inhibit excessive corrosion of the copper surface during the etching process, thereby improving the etching uniformity of the copper surface, and the copper complexing agent forms a stable complex with copper ions during the etching process, thereby preventing copper ions from re-depositing and causing etching defects.

[0033] Specifically, the corrosion inhibitor includes at least one of benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester. In fact, after copolymerization with polyethylene glycol, benzotriazole can effectively give benzotriazole polarity and flexibility, thereby improving the adsorption stability of benzotriazole on the copper surface after coordination with copper, and further improving the corrosion inhibition performance, while mercaptobenzothiazole hexadecyl ester can form a hydrophobic layer on the copper surface after complexation with copper, thereby further inhibiting the penetration of etching media and improving the corrosion inhibition effect.

[0034] In some embodiments, the corrosion inhibitor includes a benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester in a mass ratio of 1: (0.8-1.2). In fact, by combining the benzotriazole-polyethylene glycol copolymer and the mercaptobenzothiazole hexadecyl ester and adjusting the matching ratio of the two, a good synergistic effect can be achieved, so that the corrosion inhibitor forms a stably adsorbed hydrophobic layer on the copper surface during the etching process, thereby ensuring the stability of the corrosion inhibition effect.

[0035] In some embodiments, the preparation method of benzotriazole-polyethylene glycol copolymer comprises: copolymerizing benzotriazole and polyethylene glycol diacrylate under the action of an initiator, separating, washing and freeze-drying to obtain benzotriazole-polyethylene glycol copolymer. In fact, under the action of the initiator, benzotriazole can be grafted with polyethylene glycol diacrylate, and polyethylene glycol diacrylate itself can copolymerize to form a polymer network containing benzotriazole structural units.

[0036] Specifically, when benzotriazole and polyethylene glycol diacrylate are mixed, the mass ratio of benzotriazole to polyethylene glycol diacrylate is (0.1-0.3): 1. In fact, by adjusting the mixing ratio of benzotriazole and polyethylene glycol diacrylate, the welding points of the functional sites of benzotriazole in the copolymer and the proportion of the copolymerization of polyethylene glycol itself can be effectively adjusted, thereby obtaining a copolymer with better corrosion inhibition performance.

[0037] In some embodiments, when benzotriazole and polyethylene glycol diacrylate are copolymerized under the action of an initiator, the initiator used includes at least one of azobisisobutyronitrile, benzoyl peroxide, and diisopropylbenzene peroxide. In fact, when the copolymerization reaction occurs, the initiator can generate free radicals to initiate the self-polymerization reaction of polyethylene glycol diacrylate, and at the same time, it can also promote benzotriazole to participate in the copolymerization reaction of polyethylene glycol diacrylate to effectively form a copolymer.

[0038] In fact, since the amount of initiator used directly affects the rate of free radical generation, thereby affecting the rate of generation of benzotriazole-polyethylene glycol copolymer, in order to balance the reaction rate and reaction safety, the mass ratio of initiator to reactant (including benzotriazole and polyethylene glycol diacrylate) is (0.03-0.05): 1. By adjusting the amount of initiator added, the copolymerization reaction can be carried out more smoothly, and the reaction rate and safety are well balanced.

[0039] In some embodiments, when benzotriazole and polyethylene glycol diacrylate are copolymerized, the molecular weight of the polyethylene glycol diacrylate used is 200-600. In fact, polyethylene glycol diacrylate with a molecular weight between 200-600 can make the copolymer have lower viscosity and better fluidity, which is conducive to the uniform dispersion of the copolymer added in the etching solution, and can effectively improve the solubility of the copolymer.

[0040] In some embodiments, when benzotriazole and polyethylene glycol diacrylate are copolymerized, benzotriazole and polyethylene glycol diacrylate are mixed and dissolved in dimethyl sulfoxide to prepare a mixed solution. This can effectively promote the uniform mixing of benzotriazole and polyethylene glycol diacrylate, thereby improving the reaction uniformity and the uniformity of benzotriazole in the copolymer.

[0041] In some embodiments, after benzotriazole and polyethylene glycol diacrylate are mixed, copolymerization occurs in a non-oxidizing atmosphere at 70-80° C. under the action of an initiator. In fact, by selecting a suitable atmosphere and temperature environment, the promoting effect of the initiator on the reaction can be effectively improved. Specifically, the non-oxidizing atmosphere can be at least one of a nitrogen atmosphere and an inert atmosphere.

[0042] In some embodiments, benzotriazole and polyethylene glycol diacrylate react for 4-6 hours under the action of an initiator. In fact, by controlling the reaction time, the reaction process can be indirectly controlled, so that the obtained copolymer has good corrosion inhibition performance. Specifically, after the reaction is completed, the reaction system is filtered and separated, and the filtered solids are circulated and rinsed with anhydrous ethanol and deionized water, and then freeze-dried.

[0043] In fact, after the reaction of benzotriazole and polyethylene glycol diacrylate is completed, anhydrous ethanol can be added to the reaction system to change the polarity of the solvent, thereby facilitating the precipitation of the benzotriazole-polyethylene glycol copolymer from the reaction system.

[0044] In some embodiments, during freeze drying, the separated and washed solids are frozen at -40°C to -50°C, dried once in a vacuum environment at -20°C to -40°C, and then dried twice in a vacuum environment at 20°C to 40°C.

[0045] In some embodiments, the preparation method of hexadecyl mercaptobenzothiazole comprises: subjecting mercaptobenzothiazole and hexadecyl bromide to nucleophilic substitution under the action of an alkaline catalyst, and then separating and drying to obtain hexadecyl mercaptobenzothiazole. In fact, during the reaction, the sulfur atom in mercaptobenzothiazole has arc pairs of electrons and can act as a nucleophilic reagent, while the bromine in hexadecyl bromide is a leaving group, and a nucleophilic substitution reaction occurs under the alkaline catalyst to enhance the nucleophilicity.

[0046] In some embodiments, when mercaptobenzothiazole and hexadecyl bromide are reacted, the mass ratio of mercaptobenzothiazole to hexadecyl bromide is 1:(1-3). In fact, by regulating the ratio of mercaptobenzothiazole to hexadecyl bromide, the generation of by-products can be avoided while promoting the complete reaction.

[0047] In some embodiments, when the nucleophilic substitution reaction occurs under a basic catalyst, the basic catalyst used includes at least one of pyridine, triethylamine, and 4-dimethylaminopyridine. Specifically, the molar ratio of the basic catalyst to hexadecyl bromide is (0.1-0.2):1.

[0048] Specifically, when mercaptobenzothiazole and hexadecyl bromide are reacted, mercaptobenzothiazole and hexadecyl bromide are mixed and dissolved in dichloromethane to prepare a mixed solution, thereby improving the mixing uniformity of mercaptobenzothiazole and hexadecyl bromide, thereby facilitating the nucleophilic substitution reaction.

[0049] In some embodiments, mercaptobenzothiazole and hexadecyl bromide are mixed and reacted at 20-30° C. for 12-24 hours under the action of an alkaline catalyst, so that the nucleophilic substitution reaction can be completed, which is beneficial to increase the yield of mercaptobenzothiazole hexadecyl ester.

[0050] In some embodiments, after the reaction of mercaptobenzothiazole and hexadecyl bromide is completed, deionized water is added for quenching, and then the organic layer is separated, and the organic layer is dried, concentrated, and purified to obtain hexadecyl mercaptobenzothiazole.

[0051] In some embodiments, the active agent includes at least one of sodium lauryl sulfate, polyoxyethylene fatty acid esters, and sorbitan fatty acid esters; the stabilizer includes at least one of sodium tripolyphosphate, sodium carboxymethyl cellulose, and thiourea; and the copper chelating agent includes at least one of polyvinyl pyrrolidone and ethylenediaminetetraacetic acid.

[0052] In fact, the present invention also provides a method for preparing an etching additive, comprising the following steps: ball milling and blending an activator, a stabilizer, a corrosion inhibitor and a copper complexing agent to obtain an etching additive. In fact, ball milling is conducive to uniformly mixing various components, thereby improving the uniformity of the etching additive added into the etching solution.

[0053] The present invention further provides an etching solution, which includes the etching additive in any one of the above embodiments. Specifically, the mass fraction of the etching additive in the etching solution is 20-25%.

[0054] Preparation Example 1

[0055] This preparation example 1 provides a method for preparing a benzotriazole-polyethylene glycol copolymer, comprising the following steps:

[0056] Benzotriazole (CAS: 27556-51-0) and polyethylene glycol diacrylate (CAS: 26570-48-9; PEG (400) DA purchased from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.) were mixed and dissolved in dimethyl sulfoxide at a mass ratio of 0.2:1, and then ultrasonically dispersed to obtain a reaction solution;

[0057] Azobisisobutyronitrile (CAS: 78-67-1; the mass ratio of azobisisobutyronitrile to (benzotriazole + polyethylene glycol diacrylate) is 0.04:1) is stirred and dissolved in the reaction solution, and stirred and reacted for 5 hours under a nitrogen atmosphere at 75°C. After adding 5 volumes (compared to the reaction solution) of anhydrous ethanol, the mixture is filtered and separated, and rinsed three times with anhydrous ethanol and deionized water. After being quickly frozen at minus 45°C, it is transferred to a vacuum environment at minus 30°C for primary drying, and then transferred to a vacuum environment at 30°C for secondary drying to obtain a benzotriazole-polyethylene glycol copolymer.

[0058] Preparation Example 2

[0059] This Preparation Example 2 provides a preparation method for a benzotriazole-polyethylene glycol mixture, comprising the following steps: mixing benzotriazole (CAS: 27556-51-0) and polyethylene glycol (PEG400 purchased from Nantong Yixun Chemical Co., Ltd.) in a mass ratio of 0.2:1 and dissolving them in dimethyl sulfoxide, followed by ultrasonic dispersion to obtain a reaction solution; freezing the reaction solution at minus 45°C, transferring it to a vacuum environment at minus 30°C for primary drying, and then transferring it to a vacuum environment at 30°C for secondary drying to obtain a benzotriazole-polyethylene glycol mixture.

[0060] Preparation Example 3

[0061] Preparation Example 3 provides a preparation method of mercaptobenzothiazole hexadecyl ester, comprising the following steps: dissolving mercaptobenzothiazole (CAS: 149-30-4) and hexadecyl bromide (CAS: 112-82-3) in a mass ratio of 1:2 in dichloromethane, and ultrasonically mixing to obtain a mixed solution; adding pyridine (CAS: 110-86-1; the molar ratio of pyridine to hexadecyl bromide is 0.2:1) into the mixed solution, and ultrasonically mixing, and stirring the mixture at room temperature of 25°C for 18 hours; adding deionized water for quenching, separating the organic layer, and rotary evaporating to dry, and then purifying by column chromatography to obtain mercaptobenzothiazole hexadecyl ester.

[0062] Preparation Example 4

[0063] This preparation example 4 provides a preparation method of a mercaptobenzothiazole-hexadecyl bromide mixture, comprising the following steps: dissolving mercaptobenzothiazole (CAS: 149-30-4) and hexadecyl bromide (CAS: 112-82-3) in a mass ratio of 1:2 in dichloromethane and ultrasonically mixing to obtain a mixed solution; freezing the mixed solution at minus 45°C, transferring it to a vacuum environment at minus 30°C for primary drying, and then transferring it to a vacuum environment at 30°C for secondary drying to obtain a mercaptobenzothiazole-hexadecyl bromide mixture.

[0064] Example 1

[0065] This embodiment 1 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4), 8 parts of benzotriazole-polyethylene glycol copolymer (Preparation Example 1), 8 parts of mercaptobenzothiazole hexadecyl ester (Preparation Example 3) and 19 parts of polyvinyl pyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0066] Example 2

[0067] This embodiment 2 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4), 8 parts of benzotriazole-polyethylene glycol copolymer (Preparation Example 1), 8 parts of mercaptobenzothiazole-hexadecyl bromide mixture (Preparation Example 4) and 19 parts of polyvinyl pyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0068] Example 3

[0069] This embodiment 3 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4), 8 parts of benzotriazole-polyethylene glycol mixture (Preparation Example 2), 8 parts of mercaptobenzothiazole hexadecyl ester (Preparation Example 3) and 19 parts of polyvinyl pyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0070] Example 4

[0071] This embodiment 4 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4), 8 parts of a benzotriazole-polyethylene glycol mixture (Preparation Example 2), 8 parts of a mercaptobenzothiazole-hexadecyl bromide mixture (Preparation Example 4) and 19 parts of polyvinyl pyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0072] Comparative Example 1

[0073] This comparative example 1 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4), 8 parts of benzotriazole (CAS: 27556-51-0), 8 parts of mercaptobenzothiazole hexadecyl ester (Preparation Example 3) and 19 parts of polyvinyl pyrrolidone (Polyvinylpyrrolidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0074] Comparative Example 2

[0075] This comparative example 2 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4), 8 parts of benzotriazole-polyethylene glycol copolymer (Preparation Example 1), 8 parts of mercaptobenzothiazole (CAS: 149-30-4) and 19 parts of polyvinyl pyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0076] Comparative Example 3

[0077] This comparative example 3 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4), 8 parts of benzotriazole (CAS: 27556-51-0), 8 parts of mercaptobenzothiazole (CAS: 149-30-4) and 19 parts of polyvinyl pyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0078] Comparative Example 4

[0079] This comparative example 4 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium hexadecyl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4) and 19 parts of polyvinyl pyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball mill to obtain an etching additive.

[0080] Performance Testing

[0081] The etching additives prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were respectively configured with copper chloride and ammonium chloride to form etching solutions, and the concentration of copper chloride in the etching solution was 200 g / L, and the concentration of ammonium chloride was 100 g / L, and hydrochloric acid was used to adjust the pH of the etching solution to 4.0.

[0082] The etching solutions to which the etching additives prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were added were used to etch the PCB board, and the etching solution at 45° C. was sprayed on the printed circuit board at a pressure of 0.4 MPa for etching, and the etching factor of the etched printed circuit board was measured, and the results are shown in Table 1 below; after measuring the mass and surface area of ​​the copper plate, the copper plate was immersed in the etching solution and stirred at 45° C. for 1 min, then taken out and weighed after washing, and the etching rate was calculated as shown in Table 1 below.

[0083] Table 1 Etching factor of printed circuit board after etching by etching solution

[0084]

[0085] As can be seen from Table 1, the combined use of benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester in Example 1 can significantly improve the etching performance of the etching solution, while in Examples 2 and 3, the benzotriazole-polyethylene glycol mixture and the mercaptobenzothiazole-hexadecyl bromide mixture are used alone, and the etching performance of the etching solution is affected due to the difficulty in forming a stable copolymer. It can be seen from Example 4 and Comparative Example 3 that the effect of using the benzotriazole-polyethylene glycol mixture and the mercaptobenzothiazole-hexadecyl bromide mixture is equivalent to the effect of adding benzotriazole or mercaptobenzothiazole alone.

[0086] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. An etching additive, characterized in that: The composition comprises 30-60% of an active agent, 20-30% of a stabilizer, 10-20% of a corrosion inhibitor and the remainder of a copper complexing agent in terms of mass percentage; the corrosion inhibitor comprises at least one of benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester.

2. The etching additive according to claim 1, characterized in that: The corrosion inhibitor comprises a benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester in a mass ratio of 1: (0.8-1.2); And / or, the active agent includes at least one of sodium lauryl sulfate, polyoxyethylene fatty acid esters, and sorbitan fatty acid esters; And / or, the stabilizer includes at least one of sodium tripolyphosphate, sodium carboxymethyl cellulose, and thiourea; And / or, the copper complexing agent includes at least one of polyvinyl pyrrolidone and ethylenediaminetetraacetic acid.

3. The etching additive according to claim 1 or 2, characterized in that: The preparation method of the benzotriazole-polyethylene glycol copolymer comprises: copolymerizing benzotriazole and polyethylene glycol diacrylate under the action of an initiator, separating, washing and freeze-drying to obtain the benzotriazole-polyethylene glycol copolymer.

4. The etching additive according to claim 3, characterized in that: The mass ratio of the benzotriazole to the polyethylene glycol diacrylate is (0.1-0.3):1; And / or, the initiator includes at least one of azobisisobutyronitrile, benzoyl peroxide, and dicumyl peroxide; And / or, the mass ratio of the initiator to the reactant is (0.03-0.05):1, and the reactant includes the benzotriazole and the polyethylene glycol diacrylate; And / or, the molecular weight of the polyethylene glycol diacrylate is 200-600.

5. The etching additive according to claim 3, characterized in that: Mixing and dissolving the benzotriazole and the polyethylene glycol diacrylate in dimethyl sulfoxide to prepare a mixed solution; and / or, the benzotriazole and the polyethylene glycol diacrylate are mixed and then copolymerized in a non-oxidizing atmosphere at 70-80° C. under the action of an initiator; and / or, the benzotriazole and the polyethylene glycol diacrylate are copolymerized under the action of the initiator for 4-6 hours; and / or, after separation, rinsing with anhydrous ethanol and deionized water in a cycle and then freeze-drying; And / or, after separation and washing, the mixture is frozen at -40°C to -50°C, dried once in a vacuum environment at -20°C to -40°C, and then dried twice in a vacuum environment at 20°C to 40°C.

6. The etching additive according to claim 1 or 2, characterized in that: The preparation method of mercaptobenzothiazole hexadecyl ester comprises: subjecting mercaptobenzothiazole and hexadecyl bromide to nucleophilic substitution under the action of an alkaline catalyst, and then separating and drying to obtain mercaptobenzothiazole hexadecyl ester.

7. The etching additive according to claim 5, characterized in that: The mass ratio of the mercaptobenzothiazole to the hexadecyl bromide is 1:(1-3); And / or, the alkaline catalyst comprises at least one of pyridine, triethylamine, and 4-dimethylaminopyridine; And / or, the molar ratio of the alkaline catalyst to the hexadecyl bromide is (0.1-0.2):1; and / or, mixing and dissolving the mercaptobenzothiazole and the hexadecyl bromide in dichloromethane to prepare a mixed solution; and / or, the mercaptobenzothiazole and the hexadecyl bromide are mixed and reacted at 20-30° C. for 12-24 hours under the action of an alkaline catalyst; And / or, after adding deionized water, quenching and separating the organic layer, drying and concentrating and purifying to obtain mercaptobenzothiazole hexadecyl ester.

8. A method for preparing the etching additive according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: ball-milling and blending an activator, a stabilizer, a corrosion inhibitor and a copper complexing agent to obtain an etching additive.

9. An etching solution, characterized in that: The method comprises the etching additive according to any one of claims 1 to 7.

10. Use of the etching solution as claimed in claim 9 in the manufacture of printed circuit boards.

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