A fine circuit pattern anti-diffusion agent, its preparation method and usage method

Abstract

The present invention discloses a fine circuit graphic anti-diffusion agent and its preparation method and use method, relating to the field of printed circuit board manufacturing technology. The fine circuit graphic anti-diffusion agent is composed of the following mass percentage components: 0.05-0.3% oleophobic agent, 0.1-0.6% bonding agent, 0.2-1.5% adhesion promoter, 0.5-4.0% wetting agent, 0.5-5.0% cosolvent, and the balance is water; the oleophobic agent is a fluorophenylethylamine derivative, the bonding agent is a carbonyl chloride derivative, the adhesion promoter is a thiocycloalkane derivative, the wetting agent is a methylsiloxane-based silane derivative, and the cosolvent is a sulfonyl ketone derivative. The fine circuit graphic anti-diffusion agent of the present invention can form an organic layer on the copper surface of the circuit board, strengthen the bonding force between the copper surface and the ink, prevent the inkjet printing ink from spreading on the copper surface, and improve the product qualification rate of the inkjet printing solder mask process.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit board manufacturing, and in particular to a fine circuit pattern anti-diffusion agent and a preparation method and a use method thereof. Background Art

[0002] In today's printed circuit board (PCB) manufacturing, solder mask processes (methods) for fine circuits are crucial. As electronic devices and components continue to evolve toward miniaturization, higher performance, and greater sophistication, the integration and density of components on PCBs continues to increase. For example, fine-pitch components such as BGAs (ball grid arrays), QFPs (quad flat packages), and QFNs (leadless packages) often have pin pitches less than 0.5mm, placing extremely high demands on the precision of fine circuit fabrication on PCBs.

[0003] Traditional solder masking processes for fine circuits face numerous challenges. Regarding solder mask bridging, if the width of the solder mask bridges is too fine and the spacing between the bridges is too small, components are prone to cracking and detaching during production. This prevents effective isolation between pads, making it difficult to adequately prevent solder flow during soldering. This significantly increases the likelihood of solder bridging, which can ultimately cause short circuits between adjacent pins, seriously impacting product quality and performance. The traditional PCB solder mask process follows the following steps: pre-treatment → printing → pre-baking → exposure → development → post-curing. This process is currently the most commonly used and established method in PCB factories, but it also presents numerous drawbacks. First, it involves numerous steps and a complex process, requiring significant amounts of water and chemicals to be used, generating significant amounts of chemical waste. Second, the solvents in the solder mask material pose additional health and safety risks. Third, the process is time-consuming and energy-intensive. Fourth, it requires significant space, requiring a large solder mask processing workshop and a variety of process equipment.

[0004] PCB fine-line solder masking is a critical and challenging technology in modern printed circuit board (PCB) manufacturing. PCB fine-line solder masking utilizes 3D printing technology, precisely applying ink to the circuit board surface based on pre-designed data and rapidly curing it with UV light. Compared to traditional processes, this technology comprehensively optimizes the PCB solder mask coating process, offering numerous remarkable advantages. Firstly, the process flow primarily consists of three steps: pretreatment, printing, and curing. Compared to traditional image transfer methods, it offers significant material savings, reducing solder mask material usage by up to 50% and completely eliminating the use of developer chemicals. Secondly, PCB fine-line solder masking utilizes advanced exposure technologies, such as laser direct imaging (LDI), enabling high-precision pattern transfer and achieving extremely high resolution, typically reaching line widths and spacings of 10-25μm. By precisely controlling exposure energy and time, the solder mask pattern is precisely aligned with the fine lines, minimizing the risk of shorts or open circuits caused by pattern deviation. Third, to accommodate the compact layout of fine circuits, PCB fine circuit solder mask can produce an ultra-thin and uniform solder mask layer, typically controlled at a thickness of 10-25μm. This ensures excellent insulation performance and circuit protection without affecting signal transmission between circuits or increasing the difficulty of subsequent assembly due to excessive thickness. Fourth, PCB fine circuit solder mask uses high-purity, low-impurity solder mask ink to reduce the problem of electrical performance degradation caused by impurities. At the same time, the ink has excellent filling properties and can be evenly applied to the tiny gaps in fine circuits, ensuring effective insulation. Fifth, PCB fine circuit solder mask technology also offers significant advantages such as short production cycle, low cost, simplified process flow, and low environmental pollution. It is increasingly becoming a focus of industry attention and presents extremely broad development prospects.

[0005] PCB fine circuit solder mask not only requires solving the problems of high-precision equipment investment, complex process flow and high-end material investment, as well as the compatibility difficulties of different circuit materials and surface treatment methods with solder mask ink, but also requires the production environment to meet high cleanliness standards during the production process, while optimizing the ink stirring, filtration and coating processes to reduce the occurrence of tiny particulate impurities, bubbles or pinholes on product defects.

[0006] Some existing patents introduce methods related to PCB solder mask inkjet printing technology. Chinese patent CN114845474B describes a method for printing graphic solder mask on PCB, which uses an anti-diffusion liquid to pre-treat the PCB. The anti-diffusion liquid contains active ingredients such as bonding agents, strengthening agents, wetting agents, accelerators and stabilizers, which can effectively prevent the ink from diffusing on the substrate during printing. After treatment, the contact angle between the substrate surface and the solder mask ink exceeds 80°. Although the contact angle between the substrate surface and the ink is improved, it is not effective in improving the anti-diffusion performance of the copper surface. Chinese patent CN118290987A discloses a method for preparing and using a PCB inkjet printing anti-diffusion agent, which is mainly used in the pretreatment process of the PCB inkjet printing solder mask process. This anti-diffusion liquid contains active ingredients such as oleophobic agent 1, oleophobic agent 2, wetting agent, stabilizer, co-solvent, etc., which can form an organic layer on the copper surface and substrate surface of the circuit board to enhance the bonding strength between the copper surface and the substrate surface and the ink. After treatment, the contact angle between the copper surface and the solder resist ink is greater than 90°, and the contact angle between the substrate surface and the solder resist ink is greater than 80°, which can effectively prevent the printed ink from spreading on the copper surface and the substrate surface.

[0007] Existing technologies primarily address methods for preventing inkjet ink from spreading on copper and substrate surfaces. For fine circuit pattern printing, only the anti-diffusion effect of the inkjet printing on the copper surface is considered. However, this requires stricter production control. First, the integrity of the ink lines in the fine circuit patterns must be addressed, ensuring that the fine lines printed with the ink are uniform and neat. At the same time, bubbles or pinholes on the surface after curing must be avoided, which could affect the product yield. Second, product reliability tests must be passed, and the ink must adhere firmly to the copper surface, preventing it from falling off during reliability testing. Failure to meet these control requirements will increase the defective rate of the product, increase rework costs, and even result in scrap. Therefore, a fine circuit pattern anti-diffusion agent is needed to ensure the smooth progress of the fine circuit inkjet printing process. Summary of the Invention

[0008] To solve the above technical problems, the present invention provides a fine circuit graphic anti-diffusion agent and a preparation method and use method thereof, which are used in the pretreatment process of PCB fine circuit solder mask. The anti-diffusion agent contains effective ingredients such as an oleophobic agent, a bonding agent, an adhesion promoter, a wetting agent, and a cosolvent. It can form an organic layer on the copper surface of the circuit board, strengthen the bonding between the copper surface and the ink, prevent the printed ink from diffusing on the copper surface, and improve the product qualification rate of the inkjet solder mask process. It is suitable for inkjet printing of fine circuit graphics, can achieve uniform printing of solder mask ink with a line width of 15μm, and the product reliability test results are excellent, and there is no ink drop phenomenon in the immersion tin test.

[0009] The specific technical solutions include the following:

[0010] In a first aspect, a fine circuit pattern anti-diffusion agent is provided, which is composed of the following components in mass percentage: 0.05-0.3% oleophobic agent, 0.1-0.6% bonding agent, 0.2-1.5% adhesion promoter, 0.5-4.0% wetting agent, 0.5-5.0% cosolvent, and the balance is water; the oleophobic agent is a fluorophenylethylamine derivative, the bonding agent is a carbonyl chloride derivative, the adhesion promoter is a thiocycloalkane derivative, the wetting agent is a methylsiloxysilane derivative, and the cosolvent is a sulfonyl ketone derivative.

[0011] Furthermore, the fine circuit pattern anti-diffusion agent is composed of the following components in mass percentage: 0.05-0.2% oleophobic agent, 0.1-0.4% bonding agent, 0.2-1.0% adhesion promoter, 0.5-2.5% wetting agent, 0.5-3.0% cosolvent, and the balance is water.

[0012] Furthermore, the oleophobic agent is selected from one or more of o-fluorophenylethylamine (CAS No.: 52721-69-4), m-fluorophenylethylamine (CAS No.: 404-70-6), and p-fluorophenylethylamine (CAS No.: 1583-88-6).

[0013] Furthermore, the bonding agent is selected from one or more of 2-propylthiopyridine-3-carbonyl chloride (CAS No.: 175135-24-7), 2-(4-methylphenyl)thiopyridine-3-carbonyl chloride (CAS No.: 175135-78-1), and 2-methyl-5-phenylfuran-3-carbonyl chloride (CAS No.: 175276-57-0).

[0014] Furthermore, the adhesion promoter is selected from one or more of 2,2-dimethylthiol (CAS No.: 1570-58-9), 2,2-dimethylthiol (CAS No.: 6004-09-9), and 3,5-dimethyl-1,2,4-trithiol (CAS No.: 23654-92-4).

[0015] Furthermore, the wetting agent is selected from one or more of vinyl tris(dimethylsiloxane) silane (CAS No.: 15298-99-0), methyl tris(dimethylsiloxane) silane (CAS No.: 17082-46-1), and phenyl tris(dimethylsiloxane) silane (CAS No.: 18027-45-7).

[0016] Furthermore, the cosolvent is selected from one or more of 1-N-methylsulfonyl-4-piperidone (CAS No.: 218780-53-1), 2-(methylsulfonyl)acetophenone (CAS No.: 3708-04-1), and 1-toluenesulfonylpiperidin-4-one (CAS No.: 33439-27-9).

[0017] Preferably, the water is tap water or deionized water (D1 water).

[0018] In a second aspect, a method for preparing the fine circuit pattern anti-diffusion agent as described in the first aspect is provided, comprising the following steps: weighing an oleophobic agent, a bonding agent, an adhesion promoter, a wetting agent, a cosolvent, and water in sequence and adding them into a reactor, stirring and mixing at room temperature of 25-28°C for 30-35 minutes to obtain the fine circuit pattern anti-diffusion agent.

[0019] In a third aspect, a method for using the fine circuit pattern anti-diffusion agent according to the first aspect is provided, comprising the following steps: surface treating a printed circuit board using the fine circuit pattern anti-diffusion agent according to the first aspect.

[0020] Furthermore, the surface treatment temperature is 25±1° C., the surface treatment section length is 1.0 m, and the line speed is 2.0±0.1 m / min.

[0021] The beneficial effects of the present invention are as follows: the oleophobic agent in the component mainly acts on the functional groups on its molecules. These functional groups will react with the copper surface of the PCB board, reduce the surface tension of the copper surface, promote better bonding between the ink and the copper surface, and thus prevent the diffusion of the ink. The active group at one end of the bonding agent molecule will react with the metal surface to form a stable chemical bond; the active group at the other end will react chemically with the active site in the ink, thereby tightly connecting the copper surface and the ink. The adhesion promoter mainly acts on the surface of the board, enhances the adhesion of the copper surface, and ensures the yield rate of the post-processing process. The wetting agent is a surfactant with both hydrophilic and lipophilic functional groups. It can not only reduce the surface tension of the PCB surface, but also allow other effective ingredients to fully contact the PCB surface. The cosolvent can fully dissolve the insoluble substances in the component to form a stable solution. In particular, for those components that are insoluble in water, the cosolvent can make them evenly dispersed to form a stable system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a 15 μm line width circuit pattern treated with the fine circuit pattern anti-diffusion agent of Example 1 of the present invention;

[0024] Figure 2This is an optical microscope observation of the PCB ink area after using the fine circuit pattern anti-diffusion agent of Example 1 of the present invention;

[0025] Figure 3 This is a 15 μm line width circuit pattern treated with the fine circuit pattern anti-diffusion agent of Comparative Example 15 of the present invention;

[0026] Figure 4 This is an optical microscope observation of the PCB ink area after using the fine circuit pattern anti-diffusion agent of Comparative Example 15 of the present invention. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0029] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0030] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0031] In order to more fully understand the technical content of the present invention, the technical solution of the present invention is further introduced and illustrated in conjunction with specific embodiments below.

[0032] Example 1

[0033] A fine circuit pattern anti-diffusion agent is composed of the following components in percentage by weight: 0.1% of an oleophobic agent (o-fluorophenylethylamine), 0.3% of a bonding agent (2-propylthiopyridine-3-carbonyl chloride), 0.5% of an adhesion promoter (2,2-dimethylthiirane), 1.5% of a wetting agent (vinyl tris(dimethylsiloxy)silane), 1.5% of a cosolvent (1-N-methylsulfonyl-4-piperidone), and the balance being water.

[0034] The method for preparing the fine circuit pattern anti-diffusion agent comprises the following steps: weighing an oleophobic agent, a bonding agent, an adhesion promoter, a wetting agent, a cosolvent and water in sequence, adding them into a reaction kettle, and stirring and mixing them at room temperature of 25° C. for 30 minutes to obtain the fine circuit pattern anti-diffusion agent.

[0035] Example 2

[0036] A fine circuit pattern anti-diffusion agent is composed of the following components in percentage by weight: 0.1% oleophobic agent (m-fluorophenylethylamine), 0.3% bonding agent (2-(4-methylphenyl)thiopyridine-3-carbonyl chloride), 0.5% adhesion promoter (2,2-dimethylthieta), 1.5% wetting agent (methyl-tris(dimethylsiloxy)silane), 1.5% cosolvent (2-(methylsulfonyl)acetophenone), and the balance is water.

[0037] Example 3

[0038] A fine circuit pattern anti-diffusion agent is composed of the following components in percentage by mass: 0.1% oleophobic agent (p-fluorophenylethylamine), 0.3% bonding agent (2-methyl-5-phenylfuran-3-carbonyl chloride), 0.5% adhesion promoter (3,5-dimethyl-1,2,4-trithiolane), 1.5% wetting agent (phenyltris(dimethylsiloxy)silane), 1.5% cosolvent (1-p-toluenesulfonylpiperidin-4-one), and the balance is water.

[0039] Example 4

[0040] A fine circuit pattern anti-diffusion agent is composed of the following components in percentage by weight: 0.1% of an oleophobic agent (m-fluorophenylethylamine), 0.3% of a bonding agent (2-propylthiopyridine-3-carbonyl chloride), 0.5% of an adhesion promoter (3,5-dimethyl-1,2,4-trithiocyclopentane), 1.5% of a wetting agent (phenyltris(dimethylsiloxy)silane), 1.5% of a cosolvent (2-(methylsulfonyl)acetophenone), and the balance being water.

[0041] Example 5

[0042] A fine circuit pattern anti-diffusion agent is composed of the following components in percentage by mass: 0.05% of an oleophobic agent (o-fluorophenylethylamine), 0.1% of a bonding agent (2-propylthiopyridine-3-carbonyl chloride), 0.2% of an adhesion promoter (2,2-dimethylthiirane), 0.5% of a wetting agent (vinyl tris(dimethylsiloxy)silane), 0.5% of a cosolvent (1-N-methylsulfonyl-4-piperidone), and the balance being water.

[0043] Example 6

[0044] A fine circuit pattern anti-diffusion agent is composed of the following components in percentage by weight: 0.2% of an oleophobic agent (o-fluorophenylethylamine), 0.4% of a bonding agent (2-propylthiopyridine-3-carbonyl chloride), 1.0% of an adhesion promoter (2,2-dimethylthiirane), 2.5% of a wetting agent (vinyl tris(dimethylsiloxy)silane), 3.0% of a cosolvent (1-N-methylsulfonyl-4-piperidone), and the balance being water.

[0045] Comparative Example 1

[0046] The difference between Comparative Example 1 and Example 1 is that the components do not contain an oleophobic agent, and the other conditions are the same.

[0047] Comparative Example 2

[0048] The difference between Comparative Example 2 and Example 1 is that the components do not contain a bonding agent, and the other conditions are the same.

[0049] Comparative Example 3

[0050] The difference between Comparative Example 3 and Example 1 is that the components do not contain an adhesion promoter, and the other conditions are the same.

[0051] Comparative Example 4

[0052] The difference between Comparative Example 4 and Example 1 is that the components do not contain a wetting agent, and the other conditions are the same.

[0053] Comparative Example 5

[0054] The difference between Comparative Example 5 and Example 1 is that the components do not contain a co-solvent, and the other conditions are the same.

[0055] Comparative Example 6

[0056] Compared with Example 1, Comparative Example 6 differs in that the mass percentage content of the oleophobic agent in the component is 0.4%, and the other conditions are the same.

[0057] Comparative Example 7

[0058] Compared with Example 1, Comparative Example 7 differs in that the mass percentage content of the bonding agent in the components is 0.8%, and the other conditions are the same.

[0059] Comparative Example 8

[0060] Compared with Example 1, Comparative Example 8 differs in that the mass percentage content of the adhesion promoter in the component is 2.0%, and the other conditions are the same.

[0061] Comparative Example 9

[0062] Compared with Example 1, Comparative Example 9 differs in that the mass percentage content of the wetting agent in the component is 5.0%, and the other conditions are the same.

[0063] Comparative Example 10

[0064] Compared with Example 1, Comparative Example 10 differs in that the mass percentage content of the co-solvent in the components is 6.0%, and the other conditions are the same.

[0065] Comparative Example 11

[0066] Comparative Example 11 is compared with Example 1, except that the oleophobic agent component is replaced by o-phenylethylamine (CAS No.: 64-04-0) of equal mass, and the other conditions are the same.

[0067] Comparative Example 12

[0068] Comparative Example 12 is compared with Example 1, except that the component of the bonding agent is replaced by pyridine-3-carbonyl chloride (CAS No.: 1711-71-3) of equal mass, and the other conditions are the same.

[0069] Comparative Example 13

[0070] Comparative Example 13 is compared with Example 1, except that the adhesion promoter component is replaced by cyclopropane (CAS No.: 17454-53-4) of equal mass, and the other conditions are the same.

[0071] Comparative Example 14

[0072] Comparative Example 14 is compared with Example 1, except that the wetting agent component is replaced by triethylsilane (CAS No.: 617-86-7) of equal mass, and the other conditions are the same.

[0073] Comparative Example 15

[0074] Using existing technology (Chinese patent CN202210765329.1), specifically, its components, calculated by mass fraction, include:

[0075] Bonding agent (bisepoxyphenylthiol compound) 4.0%;

[0076] Strengthening agent (phenol disulfonic acid) 2.0%;

[0077] Wetting agent (3-dodecylbenzene-1,2-diol) 2.5%;

[0078] accelerator (2,4-thiazolidinedione) 1.5%;

[0079] Stabilizer (2,4-dihydroxybenzophenone) 2.0%, the balance is water.

[0080] The preparation methods of Examples 2-6 and Comparative Examples 1-15 are the same as the preparation method of the fine circuit pattern anti-diffusion agent of Example 1.

[0081] Performance test

[0082] The invention discloses a method for using a fine circuit pattern anti-diffusion agent, comprising the following steps: S1 oil removal section; S2 water washing section; S3 super coarsening section; S4 water washing section; S5 hydrochloric acid washing section; S6 water washing section; S7 spray printing anti-diffusion section; S8 water washing section; S9 drying section; and S10 spray printing pattern section.

[0083] The S1 degreasing section is used to clean printed circuit boards that require fine circuit pattern solder mask printing to remove surface impurities. The process parameters of the degreasing section are as follows: this section adopts a spraying method, the sulfuric acid concentration in the tank is 1.0%, and the balance is tap water; the degreasing tank temperature is 25±1℃, the degreasing tank length is 1.0m; the line speed is 2.0±0.1m / min, and the pressure is 1.5±0.5kg / cm 2 ;

[0084] The S2 water washing section is used to wash the printed circuit board after the S1 oil removal section with tap water. The process parameters of the water washing section are as follows: this section is immersion type, the water washing tank temperature is 25±1°C, the water washing section length is 1.0m, and the line speed is 2.0±0.1m / min;

[0085] The S3 super-roughening section is used to etch the printed circuit board that has passed through the S2 water washing section. The process parameters of the super-roughening section are as follows: this section is a spray type, the super-roughening solution in the tank is the Shenzhen Banming Technology Co., Ltd. model BTH-2085B super-roughening liquid, the super-roughening liquid is added as the original liquid, the temperature in the super-roughening tank is 25±1°C, the super-roughening section length is 1.0m; the line speed is 1.0±0.1m / min, and the spray pressure is 1.5±0.5kg / cm 2 ;

[0086] The S4 water washing section is used to wash the printed circuit board after the S3 super-roughening section with tap water. The process parameters of the water washing section are: this section is immersion type, the water washing temperature is 25±1°C, the water washing section length is 1.0m, and the line speed is 2.0±0.1m / min;

[0087] The S5 hydrochloric acid washing section is used to wash the printed circuit board after the S4 water washing section with hydrochloric acid. The process parameters of the hydrochloric acid washing section are as follows: the section is spray-type, the hydrochloric acid mass concentration is 5.0%, the balance is tap water, the temperature is 25±1°C, the water washing section length is 1.0m; the line speed is 2.0±0.1m / min, and the pressure is 1.5±0.5kg / cm 2 ;

[0088] The S6 water washing section is used to wash the printed circuit board after the S5 hydrochloric acid washing section with tap water. The process parameters of the water washing section are: this section is immersion type, the water washing temperature is 25±1°C, the water washing section length is 1.0m, and the line speed is 2.0±0.1m / min;

[0089] The S7 printing anti-diffusion section is used to perform surface treatment on the printed circuit board that has passed through the S6 water washing section. The chemical used is the fine circuit pattern anti-diffusion agent of the embodiment / comparative example of the present invention, and the tank is opened and the original liquid is used. The process parameters of the printing anti-diffusion section are: this section is immersion type, the temperature is 25±1°C, the surface treatment section length is 1.0m, and the line speed is 2.0±0.1m / min.

[0090] The S8 water washing section is used to wash the printed circuit board that has passed through the S7 inkjet printing anti-diffusion section with tap water. The process parameters of the water washing section are: this section is immersion type, the water washing temperature is 25±1°C, the water washing section length is 1.0m, and the line speed is 2.0±0.1m / min;

[0091] The S9 drying section is used to dry the printed circuit boards after the S8 washing section. The drying process parameters are: temperature of 70±5°C, drying section length of 2.0m, and line speed of 4.0±0.1m / min.

[0092] The S10 printing graphic section performs printing and curing treatment on the printed circuit board after the S9 drying section process. The ink model used is H-9100 of Shenzhen Rongda Photosensitive Technology Co., Ltd. The process parameters of the inkjet graphic section are: the printing process is carried out in a clean room environment, the width of the printed ink line is 15μm, the inkjet printing temperature is 25±0.5℃, and the curing method is ultraviolet UV curing.

[0093] The performance of the printed circuit board treated with the fine line pattern anti-diffusion agent was tested. The performance of the fine line pattern anti-diffusion agent of the present invention was analyzed mainly from two aspects:

[0094] The first is appearance inspection: Under natural light or appropriate lighting conditions, observe the neatness of the ink surface lines and any shedding after printing and curing.

[0095] The second is product reliability testing: using the immersion tin compatibility test method, the specific operation is as follows: according to the immersion tin process flow, the ink-coated PCB (PCB that has been treated with a fine circuit pattern anti-diffusion agent) is immersed in tin and the immersion tin effect is observed, that is, whether the printed circuit board loses ink after immersion tin. The immersion tin process flow includes the following steps: step (1) degreasing section; step (2) water washing section; step (3) micro-etching section; step (4) water washing section; step (5) pre-preg section; step (6) immersion tin section; step (7) hot water washing section; step (8) drying section.

[0096] Among them, the process flow (conditions) of step (1) oil removal section is consistent with that of S1 oil removal section, the process flow (conditions) of step (2) water washing section is consistent with that of S2 water washing section, the process flow of step (4) water washing section is consistent with that of S4 water washing section, and the process flow of step (8) drying section is consistent with that of S9 drying section.

[0097] The micro-etching section of step (3) is to micro-etch the printed circuit board that has passed the water washing section of step (2) to ensure that the oxide on the copper surface is completely removed. The process parameters of the micro-etching section are as follows: this section adopts a spraying method, BTH-2056 micro-etching additive is used in the micro-etching tank, the tank is opened at a volume concentration of 10%, and the balance is tap water, the micro-etching temperature is 25±1°C, the micro-etching section length is 1.0m; the line speed is 2.0±0.1m / min, and the spray pressure is 1.5±0.5kg / cm 2 ;

[0098] The pre-preg section of step (5) is to pre-preg the printed circuit board after the water washing section of step (4) with tin immersion solution to reduce the introduction of harmful and polluting substances into the tin immersion tank, so as to extend the life of the solution in the tin immersion tank. The process parameters of the pre-preg section are as follows: this section is an immersion type, and the tin immersion solution in the pre-preg tank is composed of 6.0% by mass of stannous isooctanoate, 6.0% by mass of 1-aminocyclobutanecarboxylic acid, 4.0% by mass of 2,3-dicyano-6-nitronaphthalene, 3.0% by mass of tridecylmethylammonium nitrate, 3.0% by mass of dibutyltin maleate, and the balance is tap water. The pre-preg temperature is 25±1°C, the pre-preg section length is 10.0m, and the line speed is 1.0±0.1m / min.

[0099] The tinning section of step (6) is to use tinning solution to tin the printed circuit board that has passed the prepreg section of step (5). The components of the tinning solution and the process parameters of the tinning section are consistent with those of the prepreg section of step (5);

[0100] The hot water washing section of step (7) is to use hot tap water to wash the printed circuit board that has passed the tinning section of step (6). The process parameters of the hot water washing section are: this section is immersion type, the water washing temperature is 75±1°C, the water washing section length is 1.0m, and the line speed is 2.0±0.1m / min.

[0101] The fine circuit pattern anti-diffusion agents of Examples 1-6 were subjected to appearance inspection and product reliability inspection. The test results are shown in Table 1 below:

[0102] Table 1 Appearance test and product reliability test results of Examples 1-6 and Comparative Examples 1-5

[0103]

[0104] Figure 1 This is a 15μm line width circuit pattern treated with the fine circuit pattern anti-diffusion agent of Example 1 of the present invention. Figure 2 This is an optical microscope observation of the PCB ink area after using the fine circuit pattern anti-diffusion agent of Example 1 of the present invention. Figure 1-2 As shown in Table 1, the solder resist ink of the embodiment of the present invention can be evenly and neatly printed with a line width of 15 μm, and the ink does not fall after the inkjet printing is cured, and the product reliability test results are excellent. There is no ink drop phenomenon in the immersion tin test, indicating that the fine circuit graphic anti-diffusion agent of the embodiment of the present invention can prevent the inkjet printing ink from spreading on the copper surface, and can effectively improve the product qualification rate of the inkjet printing solder resist process, and is suitable for graphic inkjet printing of fine circuits. The difference between Comparative Examples 1-5 and Example 1 is that a single component of oleophobic agent, bonding agent, adhesion promoter, wetting agent and cosolvent is lacking respectively. The test results show that oleophobic agent can reduce the surface tension of the copper surface, promote the ink to be better combined with the copper surface, prevent the ink from spreading, and when the component is missing, the ink spreads on the copper surface and cannot form a circuit. After curing, the ink falls and exposes the copper surface, and a large amount of ink drops after immersion tin. In the absence of bonding agents or adhesion promoter components, circuits break, ink falls off after curing, exposing the copper surface, and a large amount of ink falls off after tinning. This shows that bonding agents and adhesion promoters provide effective assistance for the bonding and adhesion between ink and copper surface and are indispensable. In the absence of wetting agents, circuits break, ink falls off after curing, exposing the copper surface, and a small amount of ink falls off after tinning. This shows that wetting agents have the effect of promoting full contact between other components and the PCB surface. In the absence of cosolvents, the anti-diffusion agent cannot form a stable solution, which will lead to a decline in product performance. From the test, it can be seen that the effect of the fine circuit pattern anti-diffusion agent is the result of the combined action of these five effective components. The lack of any component will reduce the detection performance.

[0105] The fine circuit pattern anti-diffusion agents of Comparative Examples 6-15 were subjected to appearance inspection and product reliability inspection. The test results are shown in Table 2 below:

[0106] Table 2 Appearance inspection and product reliability inspection results of comparative examples 6-15

[0107]

[0108] Figure 3 This is a 15 μm line width circuit pattern treated with the fine circuit pattern anti-diffusion agent of Comparative Example 15 of the present invention. Figure 4 This is an optical microscope observation of the PCB ink area after using the fine circuit pattern anti-diffusion agent of Comparative Example 15 of the present invention. Figure 3-Figure 4 As can be seen from the test results in Table 2, the product formula of Comparative Example 15 has significant defects when printing fine circuit graphics. When printing a solder mask ink with a line width of 15μm, there are problems such as circuit breakage, ink falling after printing and curing, and exposure of the copper surface. In addition, the product reliability test effect is poor, and a large amount of ink falls in the tin immersion test, indicating that the existing technical solutions are difficult to print fine circuits, while the fine circuit graphics anti-diffusion agent of the embodiment of the present invention can meet this demand. The difference between Comparative Examples 6-10 of the present invention and Example 1 is that the oleophobic agent, bonding agent, adhesion promoter, wetting agent, and cosolvent in the anti-diffusion agent are respectively higher than the upper limit of the mass percentage range defined by the present invention. The test results show that the mass percentage content of each single component is too high and will not affect the test effect. On the contrary, too high a concentration will increase the cost of the solution. Therefore, the mass percentage content of the fine circuit graphics anti-diffusion agent component of the present invention should not be too high, and the effect of the solution can be guaranteed within the concentration range of the embodiment.

[0109] Compared with Example 1, the only difference in Comparative Example 11 is that the oleophobic agent component: o-fluorophenylethylamine is replaced with o-phenylethylamine of equal mass. Compared with Example 1, the only difference in Comparative Example 12 is that the bonding agent component: 2-propylthiopyridine-3-carbonyl chloride is replaced with pyridine-3-carbonyl chloride of equal mass. Compared with Example 1, the only difference in Comparative Example 13 is that the adhesion promoter component: 2,2-dimethylthiirane is replaced with cyclopropane of equal mass. Compared with Example 1, the only difference in Comparative Example 14 is that the wetting agent component: vinyl tris(dimethylsiloxy)silane is replaced with triethylsilane of equal mass. The test results show that similar substances of each component of different types of branched groups will also affect the performance of the anti-diffusion agent.

[0110] Comparative Example 15 is compared with Example 1, except that the prior art (Chinese patent CN202210765329.1) is used. Compared with the fine circuit pattern anti-diffusion agent of the embodiment of the present invention, the fine circuit pattern anti-diffusion agent of Example 1 of the present invention has better performance on the circuit board.

[0111] In summary, the fine circuit graphic anti-diffusion agent provided by the present invention can form an organic layer on the copper surface of the circuit board, strengthen the bonding force between the copper surface and the ink, prevent the printed ink from diffusing on the copper surface, and improve the product qualification rate of the printing solder mask process. It is suitable for inkjet printing of fine circuit graphics, and can achieve uniform and neat printing of solder mask ink with a line width of 15μm. The reliability test results of the board surface after printing are excellent, and there is no ink falling phenomenon in the immersion tin test.

[0112] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A fine circuit pattern anti-diffusion agent, characterized in that: The invention is composed of the following components in percentage by mass: 0.05-0.3% oleophobic agent, 0.1-0.6% bonding agent, 0.2-1.5% adhesion promoter, 0.5-4.0% wetting agent, 0.5-5.0% cosolvent, and the balance is water; the oleophobic agent is a fluorophenylethylamine derivative, the bonding agent is a carbonyl chloride derivative, the adhesion promoter is a thiocycloalkane derivative, the wetting agent is a methylsiloxane derivative, and the cosolvent is a sulfonyl ketone derivative; The oleophobic agent is selected from one or more of o-fluorophenethylamine, m-fluorophenethylamine, and p-fluorophenethylamine; The bonding agent is selected from one or more of 2-propylthiopyridine-3-carbonyl chloride, 2-(4-methylphenyl)thiopyridine-3-carbonyl chloride, and 2-methyl-5-phenylfuran-3-carbonyl chloride; The adhesion promoter is selected from one or more of 2,2-dimethylthiol, 2,2-dimethylthiol, and 3,5-dimethyl-1,2,4-trithiol; The wetting agent is selected from one or more of vinyl tris(dimethylsiloxane)silane, methyl-tris(dimethylsiloxane)silane, and phenyl tris(dimethylsiloxane); The cosolvent is selected from one or more of 1-N-methylsulfonyl-4-piperidone, 2-(methylsulfonyl)acetophenone, and 1-toluenesulfonylpiperidin-4-one.

2. The fine circuit pattern anti-diffusion agent according to claim 1, characterized in that: The invention is composed of the following components in percentage by mass: 0.05-0.2% of oleophobic agent, 0.1-0.4% of bonding agent, 0.2-1.0% of adhesion promoter, 0.5-2.5% of wetting agent, 0.5-3.0% of cosolvent and the balance of water.

3. The method for preparing a fine circuit pattern anti-diffusion agent according to any one of claims 1 to 2, characterized in that: The following steps are involved: The oleophobic agent, bonding agent, adhesion promoter, wetting agent, cosolvent and water were weighed in sequence and added into a reaction kettle, and stirred and mixed at room temperature of 25-28° C. for 30-35 minutes to obtain a fine circuit pattern anti-diffusion agent.

4. The method for using the fine circuit pattern anti-diffusion agent according to any one of claims 1 to 2, characterized in that: The following steps are involved: The fine circuit pattern anti-diffusion agent according to any one of claims 1 to 2 is used to perform surface treatment on a printed circuit board.

5. The method for using the fine circuit pattern anti-diffusion agent according to claim 4, wherein: The surface treatment temperature is 25±1° C., the surface treatment section length is 1.0 m, and the line speed is 2.0±0.1 m / min.

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