An etching additive, its preparation method, an etching solution and applications

Abstract

The present invention provides an etching additive, a preparation method thereof, an etching solution and an application, relating to the technical field of printed circuit board manufacturing. The etching additive provided by the present invention comprises, by mass percentage, 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 comprises at least one of benzotriazole-polyethylene glycol copolymer and hexadecyl mercaptobenzothiazole. By adding at least one of benzotriazole-polyethylene glycol copolymer and hexadecyl mercaptobenzothiazole as a corrosion inhibitor, the present invention can inhibit the excessive corrosion on the copper surface during the etching process, thereby improving the uniformity of etching on the copper surface and effectively balancing the etching rate at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit board manufacturing, and particularly relates to an etching additive, a preparation method thereof, an etching solution and an application thereof. Background Art

[0002] A printed circuit board (PCB) is an important component of electronic products. With the development of the electronics industry, the production of printed circuit boards has developed extremely rapidly. In the manufacturing process of printed circuit boards, the use of a chemical reaction method to remove the unwanted 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 rate, additives are usually added to the etching solution to ensure the uniformity, speed and selectivity of etching.

[0003] Traditional etching additives mainly include cuprous chloride, ferric chloride, nitric acid and other strong acid substances, and are configured into an acidic etching solution by adding etching additives. Among them, ferric chloride is a relatively common etching additive, which has good copper dissolution performance and is widely used in the manufacture of double-sided and multi-layer PCB boards. When preparing an acidic etching solution, ferric chloride is usually 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, the etching solution added with traditional etching additives often shows a slow etching rate, which seriously restricts the production efficiency of PCB boards. In addition, the uniformity during the etching process is difficult to guarantee, 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, a preparation method thereof, an etching solution and an application thereof.

[0006] In a first aspect, an etching additive provided by the present invention comprises 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 by mass percentage; the corrosion inhibitor comprises at least one of benzotriazole-polyethylene glycol copolymer and hexadecyl mercaptobenzothiazole.

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

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

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

[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 polyvinylpyrrolidone and ethylenediaminetetraacetic acid.

[0012] Optionally, the preparation method of the benzotriazole-polyethylene glycol copolymer includes: copolymerizing benzotriazole with polyethylene glycol diacrylate under the action of an initiator, followed by separation, 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 diisopropylbenzene peroxide.

[0015] Optionally, the mass ratio of the initiator to the reactants is (0.03 - 0.05):1, and the reactants include 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 form a mixed solution.

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

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

[0020] Optionally, after separation, it is rinsed cyclically with absolute ethanol and deionized water and then freeze-dried.

[0021] Optionally, after separation and washing, it is frozen at -40°C to -50°C, then placed in a vacuum environment at -20°C to -40°C for primary drying, and then placed in a vacuum environment at 20°C to 40°C for secondary drying.

[0022] Optionally, the preparation method of the hexadecyl mercaptobenzothiazole includes: nucleophilic substitution of mercaptobenzothiazole and hexadecyl bromide under the action of a basic catalyst, followed by separation and drying to obtain hexadecyl mercaptobenzothiazole.

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

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

[0025] Optionally, the molar ratio of the basic 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 form a mixed solution.

[0027] Optionally, after the mercaptobenzothiazole and the hexadecyl bromide are mixed, under the action of a basic catalyst, the reaction is carried out at 20 - 30 °C for 12 - 24 h.

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

[0029] In a third aspect, the present invention also provides an etching solution including 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 Embodiments

[0031] To make the objectives, 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. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains.

[0032] The present invention provides an etching additive, which comprises 30-60% of an active agent, 20-30% of a stabilizer, 10-20% of an inhibitor and the balance of a copper complexing agent by mass percentage. During the etching operation, the active agent can accelerate the dissolution of copper, thus effectively improving the etching rate. At the same time, 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 contribute to forming a stable chemical environment in the etching solution. In addition, the inhibitor can inhibit the over-corrosion of the copper surface during the etching process, thereby improving the etching uniformity of the copper surface. The copper complexing agent forms a stable complex with copper ions during the etching process, thereby preventing the re-deposition of copper ions and causing etching defects.

[0033] Specifically, the inhibitor comprises at least one of benzotriazole-polyethylene glycol copolymer and hexadecyl mercaptobenzothiazole. In fact, after copolymerizing benzotriazole with polyethylene glycol, it can effectively endow benzotriazole with polarity and flexibility, thereby improving the adsorption stability of benzotriazole on the copper surface after coordinating with copper, and further improving the corrosion inhibition performance. And hexadecyl mercaptobenzothiazole can form a hydrophobic layer on the copper surface after copper complexation, and further inhibit the penetration of the etching medium, improving the corrosion inhibition effect.

[0034] In some embodiments, the inhibitor comprises a benzotriazole-polyethylene glycol copolymer and hexadecyl mercaptobenzothiazole in a mass ratio of 1:(0.8-1.2). In fact, by combining the benzotriazole-polyethylene glycol copolymer and hexadecyl mercaptobenzothiazole and regulating the compounding ratio of the two, a better synergistic effect can be achieved, so that the inhibitor forms a stable 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 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. In fact, under the action of the initiator, benzotriazole can graft with polyethylene glycol diacrylate, and in addition, polyethylene glycol diacrylate itself will undergo a copolymerization reaction to form a polymer network containing benzotriazole structural units.

[0036] Specifically, when mixing benzotriazole and polyethylene glycol diacrylate, 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 solder joints of benzotriazole functional sites in the copolymer and the copolymerization ratio of polyethylene glycol itself can be effectively adjusted, so as to obtain a copolymer with better corrosion inhibition performance.

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

[0038] In fact, since the dosage of the initiator will directly affect the generation rate of free radicals, thereby affecting the generation rate of the benzotriazole-polyethylene glycol copolymer, in order to balance the reaction rate and reaction safety, the mass ratio of the initiator to the reactants (including benzotriazole and polyethylene glycol diacrylate) is (0.03 - 0.05):1. By regulating the addition amount of the initiator, the copolymerization reaction can proceed relatively smoothly, well balancing the reaction rate and safety.

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

[0040] In some embodiments, when copolymerizing benzotriazole and polyethylene glycol diacrylate, benzotriazole and polyethylene glycol diacrylate are pre-mixed and dissolved in dimethyl sulfoxide to form a mixed solution, which 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, they undergo a copolymerization reaction 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 h 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 solid obtained by filtration is rinsed cyclically with absolute 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 solvent polarity, which is conducive to the precipitation of the benzotriazole-polyethylene glycol copolymer from the reaction system.

[0044] In some embodiments, during freeze-drying, the separated and washed solid is frozen at -40°C to -50°C and then placed in a vacuum environment at -20°C to -40°C for primary drying, and then placed in a vacuum environment at 20°C to 40°C for secondary drying.

[0045] In some embodiments, the preparation method of hexadecyl mercaptobenzothiazole includes: subjecting mercaptobenzothiazole and hexadecyl bromide to nucleophilic substitution under the action of a basic catalyst, and then separating and drying to obtain hexadecyl mercaptobenzothiazole. In fact, during the reaction, the sulfur atom in mercaptobenzothiazole has lone pair electrons and can act as a nucleophile, while the bromine in hexadecyl bromide is a leaving group, and a nucleophilic substitution reaction occurs under the enhancement of nucleophilicity by the basic catalyst.

[0046] In some embodiments, when reacting mercaptobenzothiazole with hexadecyl bromide, the mass ratio of mercaptobenzothiazole to hexadecyl bromide is 1:(1 - 3). In fact, by regulating the ratio of mercaptobenzothiazole to hexadecyl bromide, the occurrence of by-products can be avoided while promoting the completion of the reaction.

[0047] In some embodiments, when performing nucleophilic substitution reaction 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 reacting mercaptobenzothiazole with hexadecyl bromide, mercaptobenzothiazole and hexadecyl bromide are pre-mixed and dissolved in dichloromethane to form a mixed solution, which can improve the mixing uniformity of mercaptobenzothiazole and hexadecyl bromide, thus facilitating the progress of the nucleophilic substitution reaction.

[0049] In some embodiments, after mixing mercaptobenzothiazole and hexadecyl bromide, the reaction is carried out at 20 - 30°C for 12 - 24 h under the action of a basic catalyst, so as to make the nucleophilic substitution reaction complete and be conducive to improving the yield of hexadecyl mercaptobenzothiazole.

[0050] In some embodiments, after the reaction of mercaptobenzothiazole and hexadecyl bromide is completed, deionized water is added for quenching, 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 dodecyl sulfate, fatty acid polyoxyethylene ester, and sorbitan fatty acid ester; the stabilizer includes at least one of sodium tripolyphosphate, sodium carboxymethyl cellulose, and thiourea; and the copper complexing agent includes at least one of polyvinylpyrrolidone and ethylenediaminetetraacetic acid.

[0052] In fact, the present invention also provides a method for preparing an etching additive, which includes the following steps: ball-milling and blending an active agent, a stabilizer, an inhibitor, and a copper complexing agent to obtain the etching additive. In fact, ball-milling is beneficial to uniformly mix various components, thereby improving the uniformity of the etching additive added in the etching solution.

[0053] The present invention also provides an etching solution, which includes the etching additive in any 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, which includes the following steps:

[0056] Dissolve benzotriazole (CAS: 27556-51-0) and polyethylene glycol diacrylate (CAS: 26570-48-9; purchased from Wuhan Huaxiang Kejie Biotechnology Co., Ltd., PEG(400)DA) in a mass ratio of 0.2:1 in dimethyl sulfoxide, and perform ultrasonic dispersion to obtain a reaction solution;

[0057] Stir and dissolve azobisisobutyronitrile (CAS: 78-67-1; the mass ratio of azobisisobutyronitrile to (benzotriazole + polyethylene glycol diacrylate) is 0.04:1) in the reaction solution. After stirring and reacting for 5 h under a nitrogen atmosphere at 75°C, add 5 volumes (compared with the reaction solution) of absolute ethanol, then filter and separate, and wash three times with absolute ethanol and deionized water in turn. After rapid freezing at -45°C, transfer to a vacuum environment at -30°C for primary drying, and then transfer to a vacuum environment at 30°C for secondary drying to obtain the benzotriazole-polyethylene glycol copolymer.

[0058] Preparation Example 2

[0059] Preparation Example 2 provides a method for preparing a benzotriazole-polyethylene glycol mixture, which includes the following steps: Benzotriazole (CAS: 27556-51-0) and polyethylene glycol (PEG400 purchased from Nantong Yixun Chemical Co., Ltd.) are mixed at a mass ratio of 0.2:1 and dissolved in dimethyl sulfoxide, and then ultrasonically dispersed to obtain a reaction solution; the reaction solution is rapidly frozen at -45°C and then transferred to a vacuum environment at -30°C for primary drying, and then transferred to a vacuum environment at 30°C for secondary drying to obtain the benzotriazole-polyethylene glycol mixture.

[0060] Preparation Example 3

[0061] Preparation Example 3 provides a method for preparing hexadecyl mercaptobenzothiazole, which includes the following steps: Mercaptobenzothiazole (CAS: 149-30-4) and hexadecyl bromide (CAS: 112-82-3) are dissolved in dichloromethane at a mass ratio of 1:2 and ultrasonically mixed to obtain a mixed solution; pyridine (CAS: 110-86-1; the molar ratio of pyridine to hexadecyl bromide is 0.2:1) is added to the mixed solution and ultrasonically mixed, and then stirred and reacted at room temperature of 25°C for 18 h; deionized water is added for quenching, and then the organic layer is separated, and after rotary evaporation and drying, it is purified by column chromatography to obtain hexadecyl mercaptobenzothiazole.

[0062] Preparation Example 4

[0063] Preparation Example 4 provides a method for preparing a mercaptobenzothiazole-hexadecyl bromide mixture, which includes the following steps: Mercaptobenzothiazole (CAS: 149-30-4) and hexadecyl bromide (CAS: 112-82-3) are dissolved in dichloromethane at a mass ratio of 1:2 and ultrasonically mixed to obtain a mixed solution; the mixed solution is rapidly frozen at -45°C and then transferred to a vacuum environment at -30°C for primary drying, and then transferred to a vacuum environment at 30°C for secondary drying to obtain the mercaptobenzothiazole-hexadecyl bromide mixture.

[0064] Example 1

[0065] Example 1 provides a method for preparing an etching additive, which includes 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 hexadecyl mercaptobenzothiazole (Preparation Example 3) and 19 parts of polyvinylpyrrolidone (povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0066] Example 2

[0067] Example 2 of the present invention provides a method for preparing an etching additive, which includes 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 polyvinylpyrrolidone (Povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0068] Example 3

[0069] Example 3 of the present invention provides a method for preparing an etching additive, which includes 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 polyvinylpyrrolidone (Povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0070] Example 4

[0071] Example 4 of the present invention provides a method for preparing an etching additive, which includes 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 bromide mixture (Preparation Example 4), and 19 parts of polyvinylpyrrolidone (Povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0072] Comparative Example 1

[0073] Comparative Example 1 of the present invention provides a method for preparing an etching additive, which includes 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 polyvinylpyrrolidone (Povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0074] Comparative Example 2

[0075] Comparative Example 2 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium lauryl 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 polyvinylpyrrolidone (Povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0076] Comparative Example 3

[0077] Comparative Example 3 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium lauryl 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 polyvinylpyrrolidone (Povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0078] Comparative Example 4

[0079] Comparative Example 4 provides a method for preparing an etching additive, comprising the following steps: 40 parts of sodium lauryl sulfate, 25 parts of sodium tripolyphosphate (CAS: 7758-29-4) and 19 parts of polyvinylpyrrolidone (Povidone K30 purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.) are ball-milled and mixed in a ball-milling device to obtain the etching additive.

[0080] Performance Testing

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

[0082] The etching solutions added with the etching additives prepared in Examples 1 to 4 and Comparative Examples 1 to 4 are used for PCB board etching. The etching solution at 45°C is 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 is measured. The results are shown in Table 1 below; after measuring the mass and surface area of the copper plate, they are respectively immersed in the etching solution, stirred at 45°C for 1 min, then the copper plate is taken out, cleaned and weighed, and the etching rate is calculated as shown in Table 1 below.

[0083] Table 1 Etching Factor of Printed Circuit Board after Etching with Etching Solution

[0084]

[0085] As can be seen from Table 1, in Example 1, the combined use of benzotriazole-polyethylene glycol copolymer and cetyl mercaptobenzothiazole can significantly improve the etching performance of the etching solution. In Examples 2 and 3, the benzotriazole-polyethylene glycol mixture and the cetyl bromide mercaptobenzothiazole mixture are used alone. Since it is difficult to form a stable copolymer, the etching performance of the etching solution is affected. As can be seen from Example 4 and Comparative Example 3, the effects of using the benzotriazole-polyethylene glycol mixture and the cetyl bromide mercaptobenzothiazole mixture are equivalent to those of adding benzotriazole and mercaptobenzothiazole alone.

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

Claims

1. An etching additive, characterized in that: The composition comprises 30-60% active agent, 20-30% stabilizer, 10-20% corrosion inhibitor and the balance copper complexing agent in terms of mass percentage; the corrosion inhibitor comprises benzotriazole-polyethylene glycol copolymer and mercaptobenzothiazole hexadecyl ester in a mass ratio of 1:(0.8-1.2); The preparation method of the benzotriazole-polyethylene glycol copolymer comprises: copolymerizing benzotriazole and polyethylene glycol diacrylate in a mass ratio of (0.1-0.3):1 under the action of an initiator, separating, washing and freeze-drying to obtain the benzotriazole-polyethylene glycol copolymer; The preparation method of mercaptobenzothiazole hexadecyl ester comprises: subjecting mercaptobenzothiazole and hexadecyl bromide in a mass ratio of 1:(1-3) to nucleophilic substitution under the action of an alkaline catalyst, and then separating and drying to obtain mercaptobenzothiazole hexadecyl ester.

2. The etching additive according to claim 1, characterized in that: 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, characterized in that: The initiator comprises 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.

4. The etching additive according to claim 1, 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.

5. The etching additive according to claim 1, characterized in that: The alkaline catalyst includes 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.

6. A method for preparing the etching additive according to any one of claims 1 to 5, 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.

7. An etching solution, characterized in that: The method comprises the etching additive according to any one of claims 1 to 5.

8. Use of the etching solution as claimed in claim 7 in the manufacture of printed circuit boards.

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