Fine circuit pattern anti-diffusion agent as well as preparation method and use method thereof

Abstract

The invention discloses a fine circuit pattern anti-diffusion agent as well as a preparation method and a use method thereof, and relates to the technical field of printed circuit board manufacturing. The fine circuit pattern anti-diffusion agent is prepared from the following components in percentage by mass: 0.05 to 0.3 percent of an oleophobic agent, 0.1 to 0.6 percent of a bonding agent, 0.2 to 1.5 percent of an adhesion promoter, 0.5 to 4.0 percent of a wetting agent, 0.5 to 5.0 percent of a cosolvent and the balance of water, the oleophobic agent is a fluorophenylethylamine derivative, the bonding agent is a carbonyl chloride derivative, the adhesion promoter is a sulfur heterocyclic alkane derivative, the wetting agent is a methylsiloxane silane derivative, and the cosolvent is a sulfonyl ketone derivative. According to the fine circuit pattern anti-diffusion agent, an organic layer can be formed on the copper surface of a circuit board, the binding force between the copper surface and printing ink is enhanced, jet printing printing ink is prevented from diffusing on the copper surface, and the product percent of pass of a jet printing solder mask process is improved.

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 field, the solder mask process (method) of fine lines is very important. As electronic equipment and electronic components continue to develop in the direction of miniaturization, high performance, and high precision, the integration and density of components on printed circuit boards continue to increase. For example, fine-pitch components such as BGA (ball grid array), QFP (quad flat package) and QFN (leadless package), their pin spacing is often less than 0.5mm, which places extremely high demands on the precision of fine line production of printed circuit boards.

[0003] In the solder mask process of fine lines, traditional processes face many challenges. From the perspective of solder mask bridges, if the width of the solder mask bridge is designed too fine and the bridge spacing is too small, the relevant components are prone to cracking and falling off during the production process, which will make it impossible to form effective isolation between the pads, and it is difficult to fully prevent the flow of solder during the welding process, which greatly increases the probability of solder bridging, and may eventually cause short circuits between adjacent pins, seriously affecting product quality and performance. The traditional PCB solder mask process is: pre-treatment → printing → pre-baking → exposure → development → post-curing. This process is the most commonly used method in PCB factories and is relatively mature. However, traditional solder mask has many disadvantages: First, its steps are complicated and the process is complex. During the operation, a large amount of water and chemicals are consumed, which in turn generates a large amount of chemical waste; second, the solvents in the solder mask material will bring additional health hazards and safety risks; third, the process takes a long time and the energy consumption remains high; fourth, the production space requirements are high, and the solder mask processing workshop needs to occupy a large area and be equipped with a variety of different process equipment.

[0004] PCB fine line solder mask is a key and challenging technology in modern printed circuit board manufacturing. PCB fine line solder mask is a 3D printing technology that accurately prints ink on the surface of the circuit board based on pre-designed documents and quickly cures it with the help of UV irradiation. Compared with traditional processes, this technology has comprehensively optimized the PCB solder mask coating process, and many technical advantages are remarkable. First, the process flow of this technology mainly includes three links: pretreatment → printing → curing treatment. Compared with traditional image transfer methods, it performs well in material saving, can reduce the amount of solder mask materials by up to 50%, and completely abandons the use of developing chemicals. Second, PCB fine line solder mask can achieve high-precision graphics transfer and extremely high resolution by adopting advanced exposure technologies such as laser direct imaging (LDI), which can usually reach a line width / line spacing of 10-25μm. By precisely controlling the exposure energy and time, the solder mask pattern and the fine line are accurately aligned to avoid the risk of short circuit or open circuit caused by graphic deviation. Third, in order to adapt to the tight layout of fine lines, PCB fine line solder mask can prepare an ultra-thin and uniform solder mask layer, with a general thickness controlled at 10-25μm, which can not only ensure good insulation performance and protection of the lines, but also will not affect the signal transmission between lines or increase the difficulty of subsequent assembly due to excessive thickness. Fourth, PCB fine line 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 performance and can be evenly applied in the tiny gaps of fine lines to ensure insulation effect. Fifth, PCB fine line solder mask technology also has significant advantages such as short production cycle, low cost, simplified process flow and low environmental pollution. It is increasingly becoming the focus of industry attention and showing a very broad development prospect.

[0005] PCB fine circuit solder mask not only needs to solve the problems of high-precision equipment investment, complex process flow, high-end material investment, and the compatibility difficulties of different circuit materials and surface treatment methods with solder mask inks, but also needs to make the production environment meet high cleanliness standards during the production process, while optimizing the ink stirring, filtering and coating processes to reduce the tiny particle impurities, bubbles or pinholes that cause product defects.

[0006] Some existing patents introduce methods related to PCB solder mask inkjet printing technology. Chinese patent CN114845474B describes a PCB printing graphic solder mask method, which uses an anti-diffusion liquid to pre-treat the PCB. The anti-diffusion liquid contains effective ingredients such as bonding agents, reinforcing agents, wetting agents, accelerators and stabilizers, which can effectively prevent the ink from spreading 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, the effect of improving the anti-diffusion performance of the copper surface is poor. Chinese patent CN118290987A discloses a method for preparing and using a PCB inkjet printing anti-diffusion agent, which is mainly used in the pre-treatment process of PCB inkjet printing solder mask process. This anti-diffusion liquid contains effective 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 force between the copper surface and the substrate surface and the ink. After the 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 printing ink from spreading on the copper surface and the substrate surface.

[0007] The existing technology mainly introduces the method of preventing the diffusion of inkjet printing ink on the copper surface and the substrate surface. For fine circuit graphics printing, only the anti-diffusion effect of inkjet printing ink on the copper surface needs to be considered, but the production control requirements for the product are more stringent. First, the integrity of the ink circuit in the fine circuit graphics must be solved to ensure that the fine circuit printed by the ink is uniform and neat, and at the same time, bubbles or pinholes on the surface after printing and curing must be avoided, which will affect the yield of the product; second, the product reliability test must be qualified, the ink must adhere firmly to the copper surface, and the ink will not fall off during the reliability test. If the product fails to meet the control requirements, it will lead to an increase in the defective rate of the product in the process, increase the rework cost, and even cause scrapping. Therefore, a fine circuit graphics anti-diffusion agent is needed to ensure the smooth progress of the fine circuit inkjet printing process. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a fine circuit graphic anti-diffusion agent and a preparation method and a 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 oleophobic agent, bonding agent, adhesion promoter, wetting agent, co-solvent, etc., and can form an organic layer on the copper surface of the circuit board to strengthen the bonding force between the copper surface and the ink, prevent the inkjet printing ink from diffusing on the copper surface, and improve the product qualification rate of the inkjet printing 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 falling phenomenon in the tin immersion test.

[0009] The specific technical solutions include the following: 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% co-solvent, 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 co-solvent is a sulfonyl ketone derivative.

[0010] 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% co-solvent, and the balance is water.

[0011] 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).

[0012] 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).

[0013] 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).

[0014] Furthermore, the wetting agent is selected from one or more of vinyl tri(dimethylsiloxane) silane (CAS No.: 15298-99-0), methyl tri(dimethylsiloxane) silane (CAS No.: 17082-46-1), and phenyl tri(dimethylsiloxane) silane (CAS No.: 18027-45-7).

[0015] 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).

[0016] Preferably, the water is tap water or deionized water (D1 water).

[0017] 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 co-solvent and water in sequence and adding them into a reaction kettle, stirring and mixing at room temperature of 25-28°C for 30-35 minutes to obtain the fine circuit pattern anti-diffusion agent.

[0018] In a third aspect, a method for using the fine circuit pattern anti-diffusion agent as described in the first aspect is provided, comprising the following steps: using the fine circuit pattern anti-diffusion agent as described in the first aspect to perform surface treatment on a printed circuit board.

[0019] 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.

[0020] The beneficial effects of the present invention are as follows: the oleophobic agent in the component mainly plays a role depending on the functional groups on its molecules, which 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 prevent the ink from diffusing. 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, which 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, especially 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

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0022] Figure 1 A 15 μm 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 image of the PCB ink area after using the fine circuit pattern anti-diffusion agent of Example 1 of the present invention; Figure 3 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 picture of the PCB ink area after using the fine circuit pattern anti-diffusion agent of comparative example 15 of the present invention. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the present invention.

[0024] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0025] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0026] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0027] 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.

[0028] Example 1 A fine circuit pattern anti-diffusion agent, composed of the following components in mass percentage: 0.1% oleophobic agent (o-fluorophenylethylamine), 0.3% bonding agent (2-propylthiopyridine-3-carbonyl chloride), 0.5% adhesion promoter (2,2-dimethylthiirane), 1.5% wetting agent (vinyl tris(dimethylsiloxy)silane), 1.5% co-solvent (1-N-methylsulfonyl-4-piperidone), and the balance is water.

[0029] The preparation method of 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 and adding them into a reaction kettle, and stirring and mixing them at a room temperature of 25° C. for 30 minutes to obtain the fine circuit pattern anti-diffusion agent.

[0030] Example 2 A fine circuit pattern anti-diffusion agent, composed of the following components in percentage by mass: 0.1% oleophobic agent (m-fluorophenylethylamine), 0.3% bonding agent (2-(4-methylphenyl)thiopyridine-3-carbonyl chloride), 0.5% adhesion promoter (2,2-dimethylthiacyclobutane), 1.5% wetting agent (methyl-tri(dimethylsiloxy)silane), 1.5% cosolvent (2-(methylsulfonyl)acetophenone), and the balance is water.

[0031] Example 3 A fine circuit pattern anti-diffusion agent is composed of the following components in percentage by mass: 0.1% of an oleophobic agent (p-fluorophenylethylamine), 0.3% of a bonding agent (2-methyl-5-phenylfuran-3-carbonyl chloride), 0.5% of an adhesion promoter (3,5-dimethyl-1,2,4-trithiolane), 1.5% of a wetting agent (phenyltris(dimethylsiloxy)silane), 1.5% of a cosolvent (1-p-toluenesulfonylpiperidin-4-one), and the balance is water.

[0032] Example 4 A fine circuit pattern anti-diffusion agent, composed of the following components in percentage by mass: 0.1% oleophobic agent (m-fluorophenylethylamine), 0.3% bonding agent (2-propylthiopyridine-3-carbonyl chloride), 0.5% adhesion promoter (3,5-dimethyl-1,2,4-trithiocyclopentane), 1.5% wetting agent (phenyltris(dimethylsiloxy)silane), 1.5% cosolvent (2-(methylsulfonyl)acetophenone), and the balance is water.

[0033] Example 5 A fine circuit pattern anti-diffusion agent, composed of the following components in mass percentage: 0.05% oleophobic agent (o-fluorophenylethylamine), 0.1% bonding agent (2-propylthiopyridine-3-carbonyl chloride), 0.2% adhesion promoter (2,2-dimethylthiirane), 0.5% wetting agent (vinyl tris(dimethylsiloxy)silane), 0.5% co-solvent (1-N-methylsulfonyl-4-piperidone), and the balance is water.

[0034] Example 6 A fine circuit pattern anti-diffusion agent, composed of the following components in percentage by mass: 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.

[0035] Comparative Example 1 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.

[0036] Comparative Example 2 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.

[0037] Comparative Example 3 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.

[0038] Comparative Example 4 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.

[0039] Comparative Example 5 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.

[0040] Comparative Example 6 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.

[0041] Comparative Example 7 Compared with Example 1, Comparative Example 7 differs in that the mass percentage content of the bonding agent in the component is 0.8%, and the other conditions are the same.

[0042] Comparative Example 8 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.

[0043] Comparative Example 9 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.

[0044] Comparative Example 10 The difference between Comparative Example 10 and Example 1 is that the mass percentage content of the co-solvent in the components is 6.0%, and the other conditions are the same.

[0045] Comparative Example 11 Compared with Example 1, Comparative Example 11 differs in that the component of the oleophobic agent is replaced by an equal mass of o-phenylethylamine (CAS No.: 64-04-0), and the other conditions are the same.

[0046] Comparative Example 12 Compared with Example 1, Comparative Example 12 differs in that the component of the bonding agent is replaced by an equal mass of pyridine-3-carbonyl chloride (CAS No.: 1711-71-3), and the other conditions are the same.

[0047] Comparative Example 13 Compared with Example 1, Comparative Example 13 differs in that the component of the adhesion promoter is replaced by cyclopropane (CAS No.: 17454-53-4) of equal mass, and the other conditions are the same.

[0048] Comparative Example 14 Comparative Example 14 is compared with Example 1, except that the wetting agent component is replaced by an equal mass of triethylsilane (CAS No.: 617-86-7), and the other conditions are the same.

[0049] Comparative Example 15 Using the existing technology (Chinese patent CN202210765329.1), specifically, by mass fraction, its ingredients include: Bonding agent (bisepoxyphenylthiol compounds) 4.0%; Strengthening agent (phenol disulfonic acid) 2.0%; Wetting agent (3-dodecylbenzene-1,2-diol) 2.5%; Accelerator (2,4-thiazolidinedione) 1.5%; Stabilizer (2,4-dihydroxybenzophenone) 2.0%, the balance is water.

[0050] 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.

[0051] Performance test 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; S10 spray printing pattern section.

[0052] The S1 degreasing section is used to clean the printed circuit board that needs fine circuit pattern solder mask printing and remove surface impurities. The process parameters of the degreasing section are: this section adopts a spraying type, the mass concentration of sulfuric acid 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 ; The S2 washing section is used to wash the printed circuit board that has passed through the S1 degreasing section with tap water. The process parameters of the washing section are: this section is immersion type, the washing tank temperature is 25±1°C, the washing section length is 1.0m, and the line speed is 2.0±0.1m / min; 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 super-roughening liquid model BTH-2085B of Shenzhen Banming Technology Co., Ltd., 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 ; The S4 washing section is used to wash the printed circuit board after the S3 super-roughening section with tap water. The process parameters of the washing section are: this section is immersion type, the washing temperature is 25±1°C, the washing section length is 1.0m, and the line speed is 2.0±0.1m / min; 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 mass concentration of hydrochloric acid is 5.0%, the balance is tap water, the temperature is 25±1°C, the length of the water washing section is 1.0m; the line speed is 2.0±0.1m / min, and the pressure is 1.5±0.5kg / cm 2 ; The S6 water washing section is used to wash the printed circuit board that has passed through 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; 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 used according to the original liquid; 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; the line speed is 2.0±0.1m / min; The S8 water washing section is used to wash the printed circuit board that has passed through the S7 printing diffusion prevention 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; The S9 drying section is used to dry the printed circuit board 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. The S10 printing graphics 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 graphics 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.

[0053] 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 mainly analyzed from two aspects: The first is appearance inspection: Under natural light or appropriate lighting conditions, observe the neatness of the ink surface lines and the shedding condition after printing and curing. The second is product reliability testing: using the tinning compatibility test method, the specific operation is as follows: according to the tinning process flow, the PCB coated with ink (the PCB that has been treated with a fine circuit pattern anti-diffusion agent) is treated with tinning, and the tinning effect is observed, that is, whether the printed circuit board loses ink after tinning. The tinning 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) tinning section; step (7) hot water washing section; step (8) drying section.

[0054] 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.

[0055] The micro-etching section of step (3) is to micro-etch the printed circuit board that has passed through 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%, 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 / cm2 ; 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 harmful and pollutant substances brought 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; the line speed is 1.0±0.1m / min; The tinning stage of step (6) is to use tinning solution to tin the printed circuit board that has passed through the prepreg stage of step (5), and the components of the tinning solution and the process parameters of the tinning stage are consistent with those of the prepreg stage of step (5); The hot water washing section in step (7) is to use hot tap water to wash the printed circuit board that has passed the tinning section in step (6). The process parameters of the hot water washing section are: this section is an 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.

[0056] The fine circuit pattern anti-diffusion agents of Examples 1-6 were subjected to appearance inspection and product reliability inspection, and the test results are shown in Table 1 below: Table 1 Appearance test and product reliability test results of Examples 1-6 and Comparative Examples 1-5

[0057] Figure 1 The 15 μm line width circuit pattern treated with the fine circuit pattern anti-diffusion agent of Example 1 of the present invention is shown in FIG. 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 1-2As can be seen from the test results in Table 1, the embodiment of the present invention can achieve uniform and neat printing of solder mask ink with a line width of 15 μm, the ink does not fall off after the inkjet printing is cured, and the product reliability test results are excellent. There is no ink falling phenomenon in the tinning test, which shows that the fine circuit graphic anti-diffusion agent of the embodiment of the present invention can prevent the ink from spreading on the copper surface, and can effectively improve the product qualification rate of the inkjet solder mask process, and is suitable for graphic inkjet printing of fine circuits. The difference between Comparative Examples 1-5 and Example 1 is that the single components of oleophobic agent, bonding agent, adhesion promoter, wetting agent, and cosolvent are respectively lacking. The test results show that the oleophobic agent can reduce the surface tension of the copper surface, promote better combination of ink and copper surface, and prevent ink diffusion. When this component is missing, the ink diffuses on the copper surface and cannot form a circuit. After curing, the ink falls off and exposes the copper surface. There is a problem of a large amount of ink falling after tinning. When the bonding agent or adhesion promoter component is missing, the circuit will break, the ink will fall off after curing and the copper surface will be exposed, and a large amount of ink will fall off after tinning. It can be seen that the bonding agent and adhesion promoter provide effective help for the bonding and adhesion between the ink and the copper surface, and are indispensable. When the wetting agent is missing, the circuit will break, the ink will fall off after curing and the copper surface will be exposed, and a small amount of ink will fall off after tinning. This shows that the wetting agent has the effect of promoting other components to fully contact the PCB surface. When the co-solvent is missing, the anti-diffusion agent cannot form a stable solution, which will cause the product performance to decline. From the test, it can be seen that the effect of the fine circuit graphic 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.

[0058] The fine line pattern anti-diffusion agents of Comparative Examples 6-15 were subjected to appearance inspection and product reliability inspection, and the test results are shown in Table 2 below: Table 2 Appearance test and product reliability test results of comparative examples 6-15

[0059] Figure 3 The 15 μm line width circuit pattern treated with the anti-diffusion agent of the fine circuit pattern of Comparative Example 15 of the present invention is shown in FIG. Figure 4 This is an optical microscope observation of the PCB ink area after using the fine line pattern anti-diffusion agent of comparative example 15 of the present invention. Figure 3-Figure 4As 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 solder mask ink with a line width of 15μm, there are problems such as circuit breakage, ink falling off after printing and curing, and copper surface exposure. In addition, the product reliability test effect is poor, and a large amount of ink falls off in the tin immersion test, indicating that it is difficult to print fine circuits in the prior art solution, and 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 specified 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 potion. 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 potion can be guaranteed within the concentration range of the embodiment.

[0060] Compared with Example 1, the only difference in Comparative Example 11 is that the oleophobic agent component: o-fluorophenylethylamine is replaced with an equal mass of o-phenylethylamine. 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 an equal mass of pyridine-3-carbonyl chloride. Compared with Example 1, the only difference in Comparative Example 13 is that the adhesion promoter component: 2,2-dimethylthiopropane is replaced with an equal mass of cyclopropane. Compared with Example 1, the only difference in Comparative Example 14 is that the wetting agent component: vinyl tris(dimethylsiloxy)silane is replaced with an equal mass of triethylsilane. The test results show that similar substances of each component of different types of branched groups will also affect the performance of the diffusion barrier.

[0061] Compared with Example 1, Comparative Example 15 differs in 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.

[0062] 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 inkjet printing ink from diffusing on the copper surface, and improve the product qualification rate of the inkjet 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 tin immersion test.

[0063] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A fine line pattern anti-diffusion agent, characterized in that: The invention is composed of the following components in percentage by mass: 0.05-0.3% of an oleophobic agent, 0.1-0.6% of a bonding agent, 0.2-1.5% of an adhesion promoter, 0.5-4.0% of a wetting agent, 0.5-5.0% of a 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 silane derivative, and the cosolvent is a sulfonyl ketone derivative.

2. The fine line 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 co-solvent and the balance of water.

3. The fine line pattern anti-diffusion agent according to claim 1, characterized in that: The oleophobic agent is selected from one or more of o-fluorophenethylamine, m-fluorophenethylamine and p-fluorophenethylamine.

4. The fine line pattern anti-diffusion agent according to claim 1, characterized in that: 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.

5. The fine line pattern anti-diffusion agent according to claim 1, characterized in that: The adhesion promoter is selected from one or more of 2,2-dimethylthicyclopropane, 2,2-dimethylthicyclotane, and 3,5-dimethyl-1,2,4-trithicyclopentane.

6. The fine line pattern anti-diffusion agent according to claim 1, characterized in that: The wetting agent is selected from one or more of vinyl tri(dimethylsiloxane) silane, methyl-tri(dimethylsiloxane) silane, and phenyl tri(dimethylsiloxane) silane.

7. The fine line pattern anti-diffusion agent according to claim 1, characterized in that: The cosolvent is selected from one or more of 1-N-methylsulfonyl-4-piperidone, 2-(methylsulfonyl)acetophenone, and 1-toluenesulfonylpiperidin-4-one.

8. The method for preparing a fine circuit pattern anti-diffusion agent according to any one of claims 1 to 7, characterized in that: The following steps are involved: The oleophobic agent, bonding agent, adhesion promoter, wetting agent, cosolvent and water are weighed in sequence and added into a reaction kettle, and stirred and mixed for 30-35 minutes at room temperature of 25-28° C. to obtain a fine circuit pattern anti-diffusion agent.

9. The method for using the fine circuit pattern anti-diffusion agent according to any one of claims 1 to 7, characterized in that: The following steps are involved: The fine line pattern anti-diffusion agent according to any one of claims 1 to 7 is used to perform surface treatment on a printed circuit board.

10. The method for using the fine circuit pattern anti-diffusion agent according to claim 9, characterized in that: 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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