Anti-diffusion agent, preparation method of anti-diffusion agent, circuit board and solder mask processing method of circuit board

Abstract

The invention provides an anti-diffusion agent, a preparation method of the anti-diffusion agent, a circuit board and a solder mask processing method of the circuit board. The anti-diffusion agent comprises the following components in parts by mass: 0.2-5 parts of a sulfydryl nitrogen heterocyclic compound; 0.1 to 5 parts of 3-piperazinyl propyl methyl dimethoxy silane; 0.1 to 5 parts of organic acid; 0.1 to 20 parts of a surfactant; and the balance water. According to the anti-diffusion agent, the contact angle of the solder resist ink on the copper surface can be increased on the basis of well ensuring the adhesion effect of the ink, the difficulty of forming an anti-diffusion layer on the copper surface can be reduced, and the influence of the formation of the anti-diffusion layer on a circuit board can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board processing, and in particular to an anti-diffusion agent and a preparation method thereof, a circuit board and a solder resist processing method thereof. Background Art

[0002] Circuit boards are widely used in industry and daily life and are one of the important components of the modern electronics industry. With the rise of 3D printing technology, some manufacturers use ink to directly print the required solder mask layer on the 3D printer circuit board. This method can reduce the operation steps, so that the solder mask process includes grinding / micro-etching-drying-3D printing, and can reduce the use of ink and reduce the pollution caused by subsequent development. For example, the patent application with application number CN201810410002.6, but directly using liquid ink to print circuits on the circuit board, because the ink has good wetting properties with the copper surface and the contact angle is small, generally <40°, it is easy to infiltrate the copper surface, making the 3D printed ink edge easy to spread, resulting in the problem of poor precision of the solder mask layer. This phenomenon is common in high-density interconnect HDI. It is more obvious on the board. In order to improve the accuracy of the solder mask, such as the patent application with application number CN202010142937.8 and the patent application with application number CN202310101898.0, a pretreatment process is added between grinding / micro-etching and drying to form an anti-diffusion layer on the copper surface to reduce the infiltration and diffusion of ink. Another example is the patent application with application number CN202411076866.0, which discloses an anti-diffusion agent, which utilizes an aminosilane coupling agent and an alkylsilane coupling agent. However, it needs to be sprayed and dried for a long time on the surface of the circuit board to form a solidified layer. The long-term drying at 120℃-180℃ has a certain impact on the circuit board, and it is difficult to spray to form a uniform solidified layer with a thickness of microns. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide an anti-diffusion agent and a preparation method thereof, a circuit board and a solder resist processing method thereof, which can increase the contact angle of the solder resist ink on the copper surface while ensuring better adhesion of the ink, reduce the difficulty of forming an anti-diffusion layer on the copper surface, and reduce the impact of the formation of the anti-diffusion layer on the circuit board.

[0004] The object of the present invention is achieved through the following technical solutions:

[0005] An anti-diffusion agent comprises the following components in parts by weight:

[0006]

[0007] In one embodiment, the mercapto-nitrogen heterocyclic compound is at least one of mercaptobenzotriazole, mercaptobenzotetrazolyl, mercaptobenzothiazole and mercaptoimidazole.

[0008] In one embodiment, the organic acid is at least one of acetic acid, citric acid and malic acid.

[0009] In one embodiment, the surfactant is at least one of fatty alcohol polyoxyethylene ether and isomeric tridecyl alcohol polyoxyethylene isooctyl alcohol polyoxyethylene ether.

[0010] In one embodiment, the mass ratio of the mercapto nitrogen heterocyclic compound to the 3-piperazinepropylmethyldimethoxysilane is 0.8-10.

[0011] A method for preparing an anti-diffusion agent, the operating steps are as follows:

[0012] The mercapto nitrogen heterocyclic compound, 3-piperazinepropylmethyldimethoxysilane, a surfactant and an organic acid are added into water for dispersion and mixing to obtain an anti-diffusion agent.

[0013] A method for processing solder resist on a circuit board, comprising the following steps:

[0014] Get the solder mask circuit board;

[0015] Cleaning the solder resist circuit board to remove oil stains and an oxide layer on the surface of the solder resist circuit board to obtain a pretreated circuit board;

[0016] Using the anti-diffusion agent described in any of the above embodiments to perform an anti-diffusion operation on the pre-treated circuit board, so as to form an anti-diffusion layer on the copper surface of the pre-treated circuit board;

[0017] Performing a 3D ink printing operation on the anti-diffusion layer to form a solder resist ink layer on the surface of the anti-diffusion layer;

[0018] The solder resist ink layer is cured.

[0019] In one embodiment, the anti-diffusion agent is used to perform an anti-diffusion operation on the pre-treated circuit board, specifically: the pre-treated circuit board is immersed or poured with the diffusing agent.

[0020] In one embodiment, the pretreated circuit board is immersed or poured with the diffusing agent at a temperature of 10° C. to 60° C.

[0021] A circuit board is prepared by the solder resist processing method for a circuit board described in any one of the above embodiments.

[0022] Compared with the prior art, the present invention has at least the following advantages:

[0023] The anti-diffusion agent of the present invention contains 0.2 to 5 parts of a mercapto-nitrogen heterocyclic compound, which is used in combination with 0.1 to 5 parts of 3-piperazinylpropylmethyldimethoxysilane, so that the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane are synergistically and competitively bonded to the copper surface of the circuit board to form a monomolecular anti-diffusion layer. Since the molecular weights of the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane are relatively small, the thickness of the anti-diffusion layer formed on the copper surface of the circuit board is relatively small, thereby reducing the influence on the adhesion strength of the ink to the copper surface of the circuit board. In addition, 3-piperazinylpropylmethyldimethoxysilane has the effect of enhancing the adhesion of the ink to the copper surface of the circuit board. The effect of strength is that the adhesion strength of the ink on the copper surface of the circuit board is better ensured, and the synergistic effect of the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane effectively increases the contact angle of the ink on the copper surface of the circuit board through the anti-diffusion layer, thereby achieving 3D printing accuracy of the ink on the copper surface of the circuit board. In addition, since the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane can be directly used for immersing or pouring the circuit board to complete the bonding adhesion to the copper surface of the circuit board, the difficulty of forming the anti-diffusion layer on the copper surface of the circuit board is effectively reduced, and no high-temperature heating is required, which effectively reduces the impact on the performance of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A flow chart of a method for processing solder resist on a circuit board according to one embodiment of the present invention;

[0026] Figure 2 : is the contact angle of the solder resist ink of Comparative Example 1 on the copper surface;

[0027] Figure 3 This is the circuit board obtained in Comparative Example 1;

[0028] Figure 4 is the contact angle of the solder resist ink of Example 1-2 on the copper surface;

[0029] Figure 5 The circuit board obtained in Example 1-2;

[0030] Figure 6is the contact angle of the solder resist ink of Example 3-1 on the copper surface;

[0031] Figure 7 This is the circuit board obtained in Example 3-1. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0033] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] The present application provides an anti-diffusion agent. In order to better understand the anti-diffusion agent of the present application, the following further explains the anti-diffusion agent of the present application:

[0036] The anti-diffusion agent of one embodiment includes the following components in parts by weight: 0.2 to 5 parts of a mercapto nitrogen heterocyclic compound; 0.1 to 5 parts of 3-piperazinylpropylmethyldimethoxysilane; 0.1 to 5 parts of an organic acid; 0.1 to 20 parts of a surfactant; and the balance being water.

[0037] The anti-diffusion agent contains 0.2 to 5 parts of a mercapto-nitrogen heterocyclic compound, which is used in combination with 0.1 to 5 parts of 3-piperazinylpropylmethyldimethoxysilane. The mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane are synergistically and competitively bonded to the copper surface of the circuit board to form a monomolecular anti-diffusion layer. Since the molecular weight of the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane is small, the thickness of the anti-diffusion layer formed on the copper surface of the circuit board is small, which reduces the effect on the adhesion strength of the ink to the copper surface of the circuit board. In addition, 3-piperazinylpropylmethyldimethoxysilane has the effect of enhancing the adhesion of the ink to the copper surface of the circuit board. The effect of strength is that the adhesion strength of the ink on the copper surface of the circuit board is better ensured, and the synergistic effect of the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane effectively increases the contact angle of the ink on the copper surface of the circuit board through the anti-diffusion layer, thereby achieving 3D printing accuracy of the ink on the copper surface of the circuit board. In addition, since the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane can be directly used for immersing or pouring the circuit board to complete the bonding adhesion to the copper surface of the circuit board, the difficulty of forming the anti-diffusion layer on the copper surface of the circuit board is effectively reduced, and no high-temperature heating is required, which effectively reduces the impact on the performance of the circuit board.

[0038] It can be understood that the mercapto group in the mercapto nitrogen heterocyclic compound can be well bonded to the copper surface, thereby allowing the mercapto nitrogen heterocyclic compound to form a monomolecular layer on the surface of the copper layer, that is, forming a thinner molecular bonded diffusion barrier layer. However, the polarity of the mercapto nitrogen heterocyclic compound is relatively large, and when used directly, it will cause the ink to be difficult to adhere to the diffusion barrier layer, that is, the contact angle of the ink on the diffusion barrier layer is too large, exceeding 130°. Therefore, 3-piperazinylpropylmethyldimethoxysilane is used in combination with the mercapto nitrogen heterocyclic compound. The polarity of 3-piperazinylpropylmethyldimethoxysilane is relatively small, and 3-piperazinylpropylmethyl The invention discloses a novel method for preparing a copper coating layer by using 3-piperazinylpropylmethyldimethoxysilane and a mercapto-nitrogen heterocyclic compound. The method comprises the following steps: first, 3-piperazinylpropylmethyldimethoxysilane and a mercapto-nitrogen heterocyclic compound are bonded to the copper surface together with the mercapto-nitrogen heterocyclic compound; second, 3-piperazinylpropylmethyldimethoxysilane and a mercapto-nitrogen heterocyclic compound are bonded to the copper surface together; third, 3-piperazinylpropylmethyldimethoxysilane and a mercapto-nitrogen heterocyclic compound are combined to effectively enhance the hydrophilicity of the copper surface; and fourth, 3-piperazinylpropylmethyldimethoxysilane and a mercapto-nitrogen heterocyclic compound are combined to form an anti-diffusion layer with a small thickness. Thus, the combination of 3-piperazinylpropylmethyldimethoxysilane and a mercapto-nitrogen heterocyclic compound can better ensure the increase of the contact angle of the ink on the anti-diffusion layer and the adhesion strength of the ink on the anti-diffusion layer.

[0039] It can be understood that the preparation of silanes containing mercapto aromatic or aliphatic chains and nitrogen heterocycles is relatively difficult. Although the contact angle of the ink on the anti-diffusion layer can be increased, the contact angle of the ink on the anti-diffusion layer is only 70° to 90°, which is still not effective for high-density interconnect HDI boards. In the present application, 3-piperazinylpropylmethyldimethoxysilane is combined with a mercapto nitrogen heterocyclic compound to achieve a contact angle of up to 120° on the anti-diffusion layer, effectively improving the universality of the anti-diffusion agent. In addition, silanes containing mercapto aromatic or aliphatic chains and nitrogen heterocycles require a large amount of organic solvents, such as alcohol solvents, to achieve dispersion and surface bonding adhesion, which is less environmentally friendly. Moreover, due to the large molecular weight, the thickness of the anti-diffusion layer formed by bonding with the copper surface is relatively large, which further affects the adhesion strength of the ink on the anti-diffusion agent.

[0040] It can be understood that if a silane coupling agent containing amino and alkyl groups is directly used to crosslink the entire surface of the circuit board at high temperature to form an anti-diffusion layer, the silane coupling agent needs to be attached to the surface of the circuit board by spraying, and the uniformity of the spraying is largely guaranteed. It is more difficult to ensure the uniformity and thickness of the final anti-diffusion layer by soaking and pouring, and the dispersion uniformity and thickness of the anti-diffusion layer on the surface of the circuit board have a great influence on the adhesion stability of the ink; in addition, the high-temperature crosslinking time is long, which can easily cause the bending or function of the circuit board, thereby affecting the yield of the circuit board; in the present application, 3-piperazinylpropylmethyldimethoxysilane is combined with a mercapto nitrogen heterocyclic compound to form an anti-diffusion layer on the copper surface in a bonding manner, which better ensures that the thickness of the anti-diffusion layer is small and the dispersion uniformity is good, and no long-term high-temperature treatment is required. On the basis of better reducing the impact on the circuit board, the adhesion strength of the ink on the copper surface is better ensured.

[0041] It can be understood that when 3-piperazinylpropylmethyldimethoxysilane and mercapto-nitrogen heterocyclic compounds are used as anti-diffusion agents to immerse or pour on the circuit board, 3-piperazinylpropylmethyldimethoxysilane and mercapto-nitrogen heterocyclic compounds both act on the copper surface as molecules, and the substances do not change. Water washing can be quickly completed to remove organic acids, surfactants and excess 3-piperazinylpropylmethyldimethoxysilane and mercapto-nitrogen heterocyclic compounds, and the treatment efficiency is high.

[0042] In one embodiment, the diffusion barrier comprises the following components in parts by weight: 0.2% to 5% mercapto-nitrogen heterocyclic compound; 0.1% to 5% 3-piperazinylpropylmethyldimethoxysilane; 0.1% to 5% organic acid; 0.1% to 20% surfactant; and the balance water. It is understood that the combined amount of mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane as low as 0.3% can form a diffusion barrier on the copper surface.

[0043] In one embodiment, the mercapto-nitrogen heterocyclic compound is at least one of mercaptobenzotriazole, mercaptobenzotetrazolyl, mercaptobenzothiazole and mercaptoimidazole, and the mercapto-nitrogen heterocyclic compound is mercaptobenzotriazole, mercaptobenzotetrazolyl, mercaptobenzothiazole or mercaptoimidazole, thereby achieving effective diffusion prevention of the ink on the diffusion prevention layer formed on the copper surface.

[0044] In one embodiment, the mercapto-nitrogen heterocyclic compound is mercaptoimidazole and mercaptobenzothiazole. Furthermore, the mass ratio of mercaptoimidazole to mercaptobenzothiazole is (2.5-5):(1-2). Furthermore, the anti-diffusion agent is composed of mercaptoimidazole, mercaptobenzothiazole, 3-piperazinylpropylmethyldimethoxysilane, citric acid, fatty alcohol polyoxyethylene ether, and water. It can be understood that different substances have different adsorption capacities on the copper surface. The synergistic and competitive adsorption of each substance in the anti-diffusion agent on the copper surface needs to be balanced to achieve stable adhesion of the ink on the copper surface and effective anti-diffusion. The anti-diffusion agent is composed of mercaptoimidazole, mercaptobenzothiazole, 3-piperazinylpropylmethyldimethoxysilane, citric acid, fatty alcohol polyoxyethylene ether and water, and the mass ratio of the mercaptoimidazole and mercaptobenzothiazole is (2.5~5): (1~2), which effectively balances the adsorption amount of each substance in the anti-diffusion agent to achieve stable adhesion and effective anti-diffusion of the ink on the copper surface.

[0045] In one embodiment, the organic acid is at least one of acetic acid, citric acid, and malic acid. It is understood that the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane can quickly and fully adhere to the copper surface under acidic conditions to form a monomolecularly arranged diffusion barrier, thereby effectively ensuring stable adhesion of the ink to the copper surface and effectively preventing diffusion.

[0046] In one embodiment, the surfactant is at least one of fatty alcohol polyoxyethylene ether and isomeric tridecanol polyoxyethylene isooctyl polyoxyethylene ether, which achieves rapid wetting and adhesion of mercapto nitrogen heterocyclic compounds and 3-piperazinepropylmethyldimethoxysilane on the copper surface, thereby improving the efficiency of the anti-diffusion agent in forming an anti-diffusion layer on the copper surface.

[0047] It should be noted that if the amount of the mercapto-nitrogen heterocyclic compound or 3-piperazinylpropylmethyldimethoxysilane used is large or small, that is, the ratio of the mercapto-nitrogen heterocyclic compound to 3-piperazinylpropylmethyldimethoxysilane is too large or too small, it will affect the contact angle and adhesion strength of the ink on the anti-diffusion layer. Specifically, if the amount of the mercapto-nitrogen heterocyclic compound is insufficient and the amount of 3-piperazinylpropylmethyldimethoxysilane used is excessive, the anti-diffusion effect of the ink on the anti-diffusion layer will be poor; if the amount of the mercapto-nitrogen heterocyclic compound used is excessive and the amount of 3-piperazinylpropylmethyldimethoxysilane used is too small, the adhesion strength of the ink on the anti-diffusion layer will be poor. Therefore, in one embodiment, the mass ratio of the mercapto-nitrogen heterocyclic compound to the 3-piperazinylpropylmethyldimethoxysilane is 0.8 to 10. Furthermore, the mass ratio of the mercapto-nitrogen heterocyclic compound to the 3-piperazinylpropylmethyldimethoxysilane is 0.8 to 8. Furthermore, the mass ratio of the mercapto nitrogen heterocyclic compound to the 3-piperazinepropylmethyldimethoxysilane is 0.8 to 5.

[0048] The present application also provides a method for preparing an anti-diffusion agent. The steps of the method for preparing an anti-diffusion agent in one embodiment are as follows: adding a mercapto-nitrogen heterocyclic compound, 3-piperazinylpropylmethyldimethoxysilane, a surfactant, and an organic acid to water for dispersion and mixing to obtain an anti-diffusion agent.

[0049] It can be understood that the mercapto-nitrogen heterocyclic compound, 3-piperazinylpropylmethyldimethoxysilane, surfactant and organic acid are all easy to dissolve and disperse in water, so the preparation of the anti-diffusion agent can be completed by directly pouring the mercapto-nitrogen heterocyclic compound, 3-piperazinylpropylmethyldimethoxysilane, surfactant and organic acid into water for dissolution and dispersion, without the need to add a large amount of organic solvent, etc. The preparation operation is simple and convenient, and is more environmentally friendly.

[0050] The present application also provides a method for processing solder resist on a circuit board. In order to better understand the method for processing solder resist on a circuit board of the present application, the following further explains the method for processing solder resist on a circuit board of the present application:

[0051] A method for processing a solder mask on a circuit board according to one embodiment includes the following steps:

[0052] S100, obtaining a solder mask circuit board. It can be understood that the solder mask circuit board is a circuit board that has completed layer transfer and then needs to undergo solder mask processing.

[0053] S200: Cleaning the solder resist circuit board to remove oil stains and an oxide layer on the surface of the solder resist circuit board, thereby obtaining a pre-treated circuit board. It is understood that the oil stains and oxide layer on the circuit board surface significantly affect the adhesion of the subsequent anti-diffusion layer and ink. Therefore, the solder resist circuit board is subjected to grinding or micro-etching to remove the ink and oxide layer on the surface of the solder resist circuit board, thereby ensuring the adhesion strength of the subsequent anti-diffusion layer and ink to the copper surface of the circuit board.

[0054] S300: Perform an anti-diffusion operation on the pre-treated circuit board using the anti-diffusion agent described in any of the above embodiments to form an anti-diffusion layer on the copper surface of the pre-treated circuit board. It is understood that the anti-diffusion agent includes the following components in parts by weight: 0.2 to 5 parts of a mercapto-nitrogen heterocyclic compound; 0.1 to 5 parts of 3-piperazinylpropylmethyldimethoxysilane; 0.1 to 5 parts of an organic acid; 0.1 to 20 parts of a surfactant; and the balance of water. When the pre-treated circuit board is subjected to the anti-diffusion treatment, the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane synergistically and competitively bond to the copper surface of the pre-treated circuit board to form the anti-diffusion layer. Due to the synergistic effect of the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane, the anti-diffusion layer attached to the copper surface of the pre-treated circuit board has good ink anti-diffusion performance and ink adhesion strength.

[0055] S400, performing a 3D ink printing operation on the anti-diffusion layer to form a solder resist ink layer on the surface of the anti-diffusion layer. It can be understood that when the anti-diffusion agent is used to form the anti-diffusion layer on the surface of the pre-treated circuit board, due to the synergistic effect of the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane, the anti-diffusion layer attached to the copper surface of the pre-treated circuit board has good ink anti-diffusion effect and ink adhesion strength. In this way, it is better to ensure that when the 3D ink is printed on the copper surface of the pre-treated circuit board, the ink has a large contact angle and adhesion strength with the pre-treated circuit board, especially for high-density interconnect HDI boards, and better ensures the printing accuracy of the solder resist ink, that is, ensures the window opening accuracy of the solder resist ink, and ensures the solder resist processing accuracy of the circuit board.

[0056] S500 , performing a curing process on the solder resist ink layer to complete the curing formation of the solder resist ink of the circuit board.

[0057] The above-mentioned solder resist processing method for the circuit board adopts an anti-diffusion agent to perform an anti-diffusion operation on the pre-treated circuit board to form an anti-diffusion layer on the copper surface of the pre-treated circuit board. Due to the synergistic effect of the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane, the anti-diffusion layer attached to the copper surface of the pre-treated circuit board has good ink anti-diffusion effect and ink adhesion strength. The anti-diffusion layer is combined with a 3D ink printing operation to form a solder resist ink layer on the surface of the anti-diffusion layer. It is better ensured that when the 3D ink is printed on the copper surface of the pre-treated circuit board, the ink has a large contact angle and adhesion strength with the pre-treated circuit board. Especially for high-density interconnection HDI boards, the printing accuracy of the solder resist ink is better ensured, that is, the window opening accuracy of the solder resist ink is ensured, and the solder resist processing accuracy of the circuit board is ensured.

[0058] In one embodiment, a sulfuric acid-hydrogen peroxide type M101A microetchant is used to clean the solder resist circuit board. Furthermore, a sulfuric acid-hydrogen peroxide type M101A microetchant is used to clean the copper surface of the solder resist circuit board to obtain a smooth copper surface free of organic matter and oxide layer. Furthermore, the copper surface of the solder resist circuit board is cleaned for 15s to 30s at a temperature of 30°C to 45°C, and an anti-diffusion agent is used to perform an anti-diffusion operation on the copper surface of the circuit board to form an anti-diffusion layer on the copper surface of the pretreated circuit board, thereby better ensuring the anti-diffusion effect and adhesion strength of the ink on the copper surface of the circuit board.

[0059] In one embodiment, the anti-diffusion agent is used to perform an anti-diffusion operation on the pre-treated circuit board, specifically by soaking or pouring the pre-treated circuit board with the diffusing agent. Furthermore, the pre-treated circuit board is soaked or poured with the diffusing agent at a temperature of 10°C to 60°C. Furthermore, the soaking or pouring is performed for 15 seconds to 180 seconds.

[0060] In one embodiment, after soaking or pouring the pretreated circuit board with the diffusing agent and before forming the anti-diffusion layer on the copper surface of the pretreated circuit board, the circuit board solder mask processing method further includes the step of drying the pretreated circuit board. Furthermore, the pretreated circuit board is dried at a temperature of 80°C to 90°C. Furthermore, the drying time is 160s to 180s.

[0061] The present application also provides a circuit board, which is prepared by the solder resist processing method for a circuit board described in any of the above embodiments.

[0062] Compared with the prior art, the present invention has at least the following advantages:

[0063] The anti-diffusion agent of the present invention contains 0.2 to 5 parts of a mercapto-nitrogen heterocyclic compound, which is used in combination with 0.1 to 5 parts of 3-piperazinylpropylmethyldimethoxysilane, so that the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane are synergistically and competitively bonded to the copper surface of the circuit board to form a monomolecular anti-diffusion layer. Since the molecular weights of the mercapto-nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane are relatively small, the thickness of the anti-diffusion layer formed on the copper surface of the circuit board is relatively small, thereby reducing the influence on the adhesion strength of the ink to the copper surface of the circuit board. In addition, 3-piperazinylpropylmethyldimethoxysilane has the effect of enhancing the adhesion of the ink to the copper surface of the circuit board. The effect of strength is that the adhesion strength of the ink on the copper surface of the circuit board is better ensured, and the synergistic effect of the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane effectively increases the contact angle of the ink on the copper surface of the circuit board through the anti-diffusion layer, thereby achieving 3D printing accuracy of the ink on the copper surface of the circuit board. In addition, since the mercapto nitrogen heterocyclic compound and 3-piperazinylpropylmethyldimethoxysilane can be directly used for immersing or pouring the circuit board to complete the bonding adhesion to the copper surface of the circuit board, the difficulty of forming the anti-diffusion layer on the copper surface of the circuit board is effectively reduced, and no high-temperature heating is required, which effectively reduces the impact on the performance of the circuit board.

[0064] The following are some specific examples, where "%" refers to percentages by weight. It should be noted that the following examples are not exhaustive and that the materials used in the following examples are all commercially available unless otherwise specified.

[0065] Example 1

[0066] Use microetching agent to immerse microetching on the circuit board at 30℃ for 30s, then rinse with water and dry;

[0067] Soak or pour the PCB with anti-diffusion agent at 10°C for 180 seconds, then wash and dry at 80°C for 180 seconds.

[0068] Next, the circuit board is 3D printed with ink and cured.

[0069] Example 2

[0070] The circuit board was micro-etched with a micro-etching agent at 40°C for 26 seconds, then washed and dried.

[0071] Soak or pour the PCB with anti-diffusion agent at 35°C for 100 seconds, then wash and dry at 85°C for 170 seconds.

[0072] Next, the circuit board is 3D printed with ink and cured.

[0073] Example 3

[0074] Use micro-etching agent to immerse micro-etching on the circuit board at a temperature of 45℃ for 15s, then rinse with water and dry;

[0075] Soak or pour the PCB with anti-diffusion agent at 60°C for 15 seconds, then wash and dry at 90°C for 160 seconds.

[0076] Next, the circuit board is 3D printed with ink and cured.

[0077] The composition and content of the anti-diffusion agent used in Examples 1 to 3 are shown in Table 1:

[0078] Table 1: Anti-diffusion agent formulation

[0079]

[0080]

[0081]

[0082] It should be noted that the amount of anti-diffusion agent used in the above formula is the amount used when the volume of the anti-diffusion agent is 1 L; the thiol nitrogen heterocyclic compound was purchased from MacLean Reagent; 3-piperazinylpropylmethyldimethoxysilane was purchased from J&K Reagent; the organic acid was purchased from Sinopharm Reagent; the surfactant was purchased from Sinopec; the 3D printing ink was purchased from Japan Taiyo Ink; the micro-etching agent is a conventional commercial sulfuric acid-hydrogen peroxide type M101A micro-etching agent; in addition, Examples 1-1 to 1-16 are for treating the circuit board using the method of Example 1; Example 2-1 is for treating the circuit board using the method of Example 2; and Example 3-1 is for treating the circuit board using the method of Example 3.

[0083] The contact angle and bonding force of the inks obtained in Comparative Example 1, Examples 1-1 to 1-6, and 2-1 and 3-1 are tested below. The only difference between Comparative Example 1 and Example 1 is that the step of soaking or pouring the circuit board with an anti-diffusion agent is omitted.

[0084] 1. Test method:

[0085] Contact angle test: Use DYT-600Z optical contact angle test;

[0086] Adhesion test: Refer to national standards GB / T9286-2021 and IS2409-2020, and use QFH-HG600 grid knife tester for testing;

[0087] 2. Test results

[0088]

[0089]

[0090] Please see Figures 2 to 3 The contact angle of the solder resist ink in Comparative Example 1 is 12.6, and the contact angles of the solder resist inks in Examples 1-1 to 1-18 and Examples 2-1 to 3-1 can reach above 90°, which can better achieve a clear and non-diffusion-free printed outline of the solder resist ink. In particular, the contact angles of the solder resist inks in Examples 2-1 and 3-1 with the copper surface are above 108°, which better achieves the anti-diffusion effect of the solder resist ink on the copper surface, thereby better ensuring the clarity and accuracy of the printed circuits on the circuit board.

[0091] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A diffusion prevention agent, characterized in that: The composition comprises the following components in parts by weight:

2. The anti-diffusion agent according to claim 1, characterized in that The mercapto nitrogen heterocyclic compound is at least one of mercaptobenzotriazole, mercaptobenzotetrazolyl, mercaptobenzothiazole and mercaptoimidazole.

3. The anti-diffusion agent according to claim 1, characterized in that The organic acid is at least one of acetic acid, citric acid and malic acid.

4. The anti-diffusion agent according to claim 1, characterized in that The surfactant is at least one of fatty alcohol polyoxyethylene ether and isomeric tridecanol polyoxyethylene isooctyl alcohol polyoxyethylene ether.

5. The anti-diffusion agent according to claim 1, characterized in that The mass ratio of the mercapto nitrogen heterocyclic compound to the 3-piperazinepropylmethyldimethoxysilane is 0.8-10.

6. A method for preparing an anti-diffusion agent, characterized in that: The steps are as follows: The mercapto nitrogen heterocyclic compound, 3-piperazinepropylmethyldimethoxysilane, a surfactant and an organic acid are added into water for dispersion and mixing to obtain an anti-diffusion agent.

7. A method for processing solder resist of a circuit board, characterized in that: The solder resist processing method of the circuit board comprises the following steps: Get the solder mask circuit board; Cleaning the solder resist circuit board to remove oil stains and an oxide layer on the surface of the solder resist circuit board to obtain a pretreated circuit board; Using the anti-diffusion agent according to any one of claims 1 to 5 to perform an anti-diffusion operation on the pre-treated circuit board, so as to form an anti-diffusion layer on the copper surface of the pre-treated circuit board; Performing a 3D ink printing operation on the anti-diffusion layer to form a solder resist ink layer on the surface of the anti-diffusion layer; The solder resist ink layer is cured.

8. The method for processing solder resist of a circuit board according to claim 7, wherein: The anti-diffusion operation is performed on the pre-treated circuit board using the anti-diffusion agent, specifically by soaking or pouring the pre-treated circuit board using the diffusant.

9. The method for processing solder resist of a circuit board according to claim 8, wherein: Under the condition of a temperature of 10° C. to 60° C., the pretreated circuit board is immersed or poured with the diffusing agent.

10. A circuit board, characterized in that: The circuit board is prepared by the solder resist processing method according to any one of claims 8 to 9.

Images