PCB inkjet printing anti-diffusion agent and preparation method and use method thereof

Abstract

The application discloses a PCB ink-jet printing anti-diffusion agent and a preparation method and use method thereof, and relates to the technical field of PCB film processing. The PCB ink-jet printing anti-diffusion agent comprises the following components in percentage by mass: 0.15-0.6% of an oil-repellent agent, 0.2-1.0% of a wetting agent, 0.5-2.5% of a stabilizer, 0.1-3.0% of a cosolvent, and the balance of water; the oil-repellent agent is a mixture of dicyclohexane crown ether derivatives and amino naphthalene sulfonic acid derivatives; the wetting agent is a betaine derivative; the stabilizer is a methylene glycol derivative; and the cosolvent is a piperidine alcohol derivative. The PCB ink-jet printing anti-diffusion agent can form an organic layer on the copper surface of a circuit board and the surface of a substrate, can strengthen the bonding force between the copper surface and the substrate surface and ink, can prevent the diffusion of the ink on the copper surface and the substrate surface, and can improve the product qualification rate of the ink-jet printing solder resist process.

Description

Technical Field

[0001] This invention relates to the field of PCB film processing technology, and in particular to a PCB inkjet printing anti-diffusion agent and its preparation and application methods. Background Technology

[0002] PCB inkjet printing technology involves spraying ink onto a circuit board using pre-designed specifications, followed by instant curing via UV irradiation. Inkjet printing significantly improves the PCB solder mask coating process, boasting numerous attractive technical advantages. It's an additive process, enabling digital printing, contactless operation, high speed, material savings, and precise printing. The ink is solvent-free. The PCB inkjet printing process involves pretreatment → printing → curing. Compared to traditional image transfer methods, it can save up to 50% of solder mask material and completely avoids the use of developing chemicals. Its short production cycle, low production cost, simplified process, and minimal environmental pollution are increasingly attracting attention and indicate a very promising future.

[0003] Existing patents describe methods related to inkjet printing technology. Chinese Patent 202210765329.1 describes a method for printing patterned solder resist on PCBs using inkjet printing. This method uses an anti-diffusion liquid to pretreat the PCB. The anti-diffusion liquid contains bonding agents, strengthening agents, wetting agents, accelerators, and stabilizers, which can form an organic layer on the surface of the circuit board substrate. This strengthens the adhesion between the substrate surface and the ink, prevents the ink from diffusing on the substrate surface, and improves the product yield of the inkjet solder resist printing process. While this method introduces a way to increase the contact angle between the substrate surface and the ink, its diffusion performance on copper surfaces and ink is very poor.

[0004] Since a complete circuit board consists of a copper surface and a substrate, the anti-diffusion agent needs to have an anti-diffusion effect on both the copper surface and the substrate simultaneously. This requires controlling the contact angle between the ink and the copper surface and substrate to be greater than 70°. A contact angle that is too low will cause the ink to spread on the copper surface and substrate of the circuit board, resulting in uneven ink printing. After ink spreads on the copper surface and substrate, some areas may lack ink protection, leading to an increased product defect rate, increased rework costs, and even scrapping. Therefore, it is necessary to find an anti-diffusion agent for PCB inkjet printing, along with its preparation and application methods, that can simultaneously maintain a good contact angle between the ink and the copper surface and substrate, ensuring the smooth progress of the inkjet printing process. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a PCB inkjet printing anti-diffusion agent, its preparation method, and its application method. This PCB inkjet printing anti-diffusion agent can form an organic layer on the copper surface and substrate surface of the circuit board, strengthening the adhesion between the ink and the copper and substrate surfaces, preventing the ink from diffusing on the copper and substrate surfaces, and improving the product yield of the solder resist printing process.

[0006] Specifically, the following technical solutions are included:

[0007] In a first aspect, a PCB inkjet printing anti-diffusion agent is provided, comprising the following components by weight percentage:

[0008] Oleophobic agent 0.15-0.6%, wetting agent 0.2-1.0%, stabilizer 0.5-2.5%, cosolvent 0.1-3.0%, balance water;

[0009] The oleophobic agent is a mixture of a dicyclohexane crown ether derivative and an aminonaphthalene sulfonic acid derivative; the wetting agent is a betaine derivative; the stabilizer is a methyl diaminobenzoate derivative; and the cosolvent is a piperidinol derivative.

[0010] Furthermore, the dicyclohexane crown ether derivative is present in 0.05-0.2% of the PCB inkjet printing antidiffusion agent by mass, and the aminonaphthalene sulfonic acid derivative is present in 0.1-0.4% of the PCB inkjet printing antidiffusion agent by mass.

[0011] Furthermore, the mass ratio of the dicyclohexane crown ether derivative to the aminonaphthalenesulfonic acid derivative is 1:(1.0-4.0).

[0012] Furthermore, the dicyclohexane crown ether derivative is one or more of dicyclohexano-24-crown ether-8 (CAS No.: 17455-23-1) and dicyclohexano-18-crown ether-6 (CAS No.: 16069-36-6).

[0013] Furthermore, the aminonaphthalenesulfonic acid derivative is one or more of 5-amino-2-naphthalenesulfonic acid (CAS No.: 119-79-9) and 6-amino-1-naphthalenesulfonic acid (CAS No.: 81-05-0).

[0014] Furthermore, the wetting agent is one or more of 3-sulfopropyltetradecyl dimethyl betaine (CAS No.: 14933-09-6) and citrate betaine (CAS No.: 17671-50-0).

[0015] Furthermore, the stabilizer is one or more of methyl 3,4-diaminobenzoate (CAS No.: 36692-49-6) and methyl 2,3-diaminobenzoate (CAS No.: 107582-20-7).

[0016] Furthermore, the co-solvent is one or more of 1-amino-4-piperidinol (CAS No.: 79414-82-7) and 1-methyl-4-phenyl-4-piperidinol (CAS No.: 4972-68-3).

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

[0018] Secondly, a method for preparing the anti-diffusion agent for PCB inkjet printing as described in the first aspect is provided, comprising the following steps: weighing an oleophobic agent, a wetting agent, a stabilizer, a cosolvent, and water in sequence and adding them to a reaction vessel, and stirring and mixing at 23-25°C for 30-40 minutes to obtain the anti-diffusion agent for PCB inkjet printing.

[0019] Thirdly, a method for using the PCB inkjet printing anti-diffusion agent as described in the first aspect is provided, comprising the following steps: using the PCB inkjet printing anti-diffusion agent to perform surface treatment on the printed circuit board, wherein the surface treatment temperature is 25±5℃, the surface treatment line speed is 4.0±0.3m / min, and the surface treatment method is immersion.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention provides an anti-diffusion agent for PCB inkjet printing, its preparation method, and its application method. The agent primarily relies on oleophobic molecules containing two types of functional groups to provide adhesion between the ink and the copper and substrate surfaces. The oleophobic agent undergoes a bonding reaction with the ink through dicyclohexane crown ether derivatives and substances containing oxygen, nitrogen, and sulfur oleophobic groups, firmly adhering the ink to the copper and substrate surfaces. The wetting agent, containing both hydrophilic and oleophilic functional groups, reduces the surface tension of the copper and substrate surfaces, allowing the oleophobic components in the anti-diffusion agent to fully contact the circuit board surface, facilitating strong bonding between the circuit board surface and the ink. The stabilizer maintains the chemical balance between the components, preventing photo-, thermal, or oxidative decomposition, thereby improving the stability of the solution and ensuring long-term excellent bonding performance. The cosolvent dissolves water-insoluble components in the solution, forming a stable solution. Based on this, the PCB inkjet printing anti-diffusion agent of the present invention can form an organic layer on the copper surface and substrate surface of the circuit board, strengthen the adhesion between the copper surface and substrate surface and the ink, prevent the inkjet ink from diffusing on the copper surface and substrate surface, and improve the product qualification rate of the inkjet solder resist process. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a real image of the printed circuit board treated with an anti-diffusion agent for inkjet printing according to Embodiment 1 of the present invention, after an ink diffusion test.

[0024] Figure 2 This is a schematic diagram of the contact angle test performed on the printed circuit board after anti-diffusion agent treatment for inkjet printing according to Embodiment 1 of the present invention.

[0025] Figure 3 This is a real image of the printed circuit board treated with an anti-diffusion agent for inkjet printing, which is Comparative Example 15 of this invention, after an ink diffusion test.

[0026] Figure 4 This is a schematic diagram of the contact angle test performed on the printed circuit board treated with the anti-diffusion agent for inkjet printing, which is Comparative Example 15 of this invention. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections 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 invention. As used in this specification and the 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 also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0031] To better understand the technical content of the present invention, the technical solution of the present invention will be further introduced and explained below with reference to specific embodiments.

[0032] Preparation method of anti-diffusion agent for PCB inkjet printing:

[0033] Weigh out the oleophobic agent, wetting agent, stabilizer, cosolvent and water in sequence and add them to the reaction vessel. Stir and mix at 23-25℃ for 30-40 minutes to obtain the PCB inkjet printing anti-diffusion agent.

[0034] Instructions for using anti-diffusion agent in PCB inkjet printing:

[0035] The PCB was surface-treated using an anti-diffusion agent for inkjet printing. The surface treatment temperature was 25±5℃, the surface treatment line speed was 4.0±0.3m / min, and the surface treatment method was immersion.

[0036] Performance testing:

[0037] First, an anti-diffusion agent for PCB inkjet printing is applied in a PCB inkjet solder mask printing process. This PCB inkjet solder mask printing process includes the following steps:

[0038] S1. Feeding section; S2. Degreasing section; S3. First water wash section; S4. Ultra-roughening section; S5. Second water wash section; S6. Hydrochloric acid wash section; S7. Third water wash section; S8. Anti-diffusion section; S9. Fourth water wash section; S10. Drying section; S11. Inkjet printing section;

[0039] The S1 feeding section is for feeding the printed circuit board that needs to be inkjet printed. The surface roughness Ra of the circuit board is 0.2-0.5. The process parameters of the feeding section are: feeding section length 2.0 m, temperature 25±5℃, and linear speed 2.0±0.3m / min.

[0040] The S2 degreasing section removes oil from the printed circuit board that has passed through the S1 feeding section using DI water and sulfuric acid. The process parameters for the degreasing section are: sulfuric acid concentration of 1.5%, with the remainder being DI water; temperature of 25±5℃; length of the degreasing section of 3.0 m; linear velocity of 2.0±0.3 m / min; and pressure of 1.5±0.5 kg / cm². 2 ;

[0041] The first water washing section S3 is used to wash the printed circuit board after passing through the degreasing section S2 with DI water. The process parameters for the first water washing section are: temperature 25±5℃, length of the water washing section 3.0 m; linear speed 2.0±0.3 m / min, and pressure 1.5±0.5 kg / cm. 2 ;

[0042] The S4 ultra-roughening section involves etching the printed circuit board (PCB) that has passed through the first water washing section (S3) with DI solution. The process parameters for the ultra-roughening section are as follows: the ultra-roughening solution in the tank is BTH-2086 stock solution from Banming Technology; temperature is 25±5℃; length of the ultra-roughening section is 3.0 m; linear velocity is 4.0±0.3 m / min; and pressure is 1.5±0.5 kg / cm². 2 The ultra-roughening etching depth is between 0.8 and 1.2 μm.

[0043] The second water washing section (S5) involves washing the printed circuit board (PCB) that has passed through the S4 ultra-roughening section with DI water. The process parameters for the second water washing section are: temperature 25±5℃, length 3.0m, linear speed 2.0±0.3 m / min, and pressure 1.5±0.5 kg / cm². 2 ;

[0044] The S6 hydrochloric acid washing section is used to wash the printed circuit board that has passed through the second water washing section (S5) with hydrochloric acid. The process parameters for the hydrochloric acid washing section are: temperature 25±5℃, water washing section length 3.0m; linear speed 2.0±0.3m / min, pressure 1.5±0.5kg / cm. 2 ;

[0045] The third water washing section (S7) involves rinsing the printed circuit board (PCB) that has passed through the hydrochloric acid washing section (S6) with DI water. The process parameters for the third water washing section are: temperature 25±5℃, length of the washing section 3.0 m, linear speed 2.0±0.3 m / min, and pressure 1.5±0.5 kg / cm². 2 ;

[0046] The S8 anti-diffusion section involves surface treatment of the printed circuit board that has passed through the S7 third water washing section using a PCB inkjet printing anti-diffusion agent. The process parameters for the anti-diffusion section are: temperature 25±5℃, length 2.0m, and linear speed 4.0±0.3m / min. This section is an immersion type.

[0047] The fourth water washing section (S9) is used to wash the printed circuit board that has passed through the anti-diffusion section (S8) with DI water. The process parameters for the fourth water washing section are: temperature 25±5℃, length of the washing section 3.0m; linear velocity 2.0±0.3m / min, and pressure 1.5±0.5kg / cm. 2 ;

[0048] The S10 drying section dries the circuit boards after the fourth water washing section (S9). The drying process parameters are: temperature 70±5℃, drying section length 4.0m; linear velocity 2.0±0.3m / min, and pressure 1.5±0.5 kg / cm². 2 .

[0049] The S11 inkjet printing section inkjet prints ink onto the circuit board after the S10 drying section. The ink used is H-9100 from Shenzhen Rongda Photosensitive Technology Co., Ltd. The process parameters for the inkjet printing section are: temperature 25±5℃, single-sided printing time 1 minute, and double-sided printing. After completion, the performance of the anti-diffusion agent in the PCB inkjet printing is tested.

[0050] The performance of the PCB inkjet printing anti-diffusion agent of this invention mainly reflects whether the solder resist ink diffuses on the copper and substrate surfaces of the printed circuit board after the PCB inkjet printing solder resist process (inkjet printing). This is analyzed from two main aspects: First, ink diffusion testing: visual observation of the solder resist ink diffusion on the printed circuit board surface; second, contact angle testing: measuring the contact angle between the copper and substrate surfaces of the printed circuit board and the solder resist ink using a contact angle meter. Specifically, ink is dripped onto the copper / substrate surface using a syringe, and the contact angle meter (manufacturer: Shanghai Fangrui Instrument Co., Ltd., model: JCY-1) is used for testing. A larger contact angle indicates that the PCB inkjet printing anti-diffusion agent reduces the surface energy of the copper / substrate surface, thus enhancing the adhesion between the copper / substrate surface and the solder resist ink.

[0051] Example 1

[0052] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0053] The composition includes: 0.4% oleophobic agent (composed of 0.1% dicyclohexano-18-crown ether-6 and 0.3% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 3,4-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0054] The preparation method of the PCB inkjet printing anti-diffusion agent includes the following steps:

[0055] Weigh out the oleophobic agent, wetting agent, stabilizer, cosolvent and water in sequence and add them to the reaction vessel. Stir and mix at 25°C for 30 minutes to obtain the PCB inkjet printing anti-diffusion agent.

[0056] The method of using the PCB inkjet printing anti-diffusion agent includes the following steps: using the PCB inkjet printing anti-diffusion agent to treat the surface of the printed circuit board, the surface treatment temperature is 25℃, the surface treatment line speed is 4.0m / min, and the surface treatment method is immersion.

[0057] The preparation and application methods of the inkjet printing anti-diffusion agents in Examples 2-6 and Comparative Examples 1-15 are the same as those in Example 1.

[0058] Example 2

[0059] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0060] The composition includes: 0.4% oleophobic agent (composed of 0.2% dicyclohexano-18-crown ether-6 and 0.2% 6-amino-1-naphthalenesulfonic acid), 0.8% wetting agent (citric acid betaine), 2.0% stabilizer (methyl 2,3-diaminobenzoate), 2.0% cosolvent (1-methyl-4-phenyl-4-piperidinol), and the balance being water.

[0061] Example 3

[0062] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0063] The composition includes: 0.35% oleophobic agent (composed of 0.15% dicyclohexano-24-crown ether-8 and 0.2% 6-amino-1-naphthalenesulfonic acid), 1.0% wetting agent (citric acid betaine), 2.5% stabilizer (methyl 2,3-diaminobenzoate), 1.5% cosolvent (1-methyl-4-phenyl-4-piperidinol), and the balance being water.

[0064] Example 4

[0065] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0066] The composition includes: 0.45% oleophobic agent (composed of 0.1% dicyclohexano-18-crown ether-6 and 0.35% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 2,3-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0067] Example 5

[0068] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0069] The composition includes: 0.6% oleophobic agent (composed of 0.2% dicyclohexano-24-crown ether-8 and 0.4% 5-amino-2-naphthalenesulfonic acid), 1.0% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 2.5% stabilizer (methyl 3,4-diaminobenzoate), 3.0% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0070] Example 6

[0071] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0072] The composition includes: 0.25% oleophobic agent (composed of 0.05% dicyclohexano-24-crown ether-8 and 0.2% 5-amino-2-naphthalenesulfonic acid), 0.2% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 0.5% stabilizer (methyl 3,4-diaminobenzoate), 0.1% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0073] Comparative Example 1

[0074] The difference between Comparative Example 1 and Example 1 is that the only oleophobic agent is 5-amino-2-naphthalenesulfonic acid, while all other conditions are the same.

[0075] Comparative Example 2

[0076] The difference between Comparative Example 2 and Example 1 is that the only oleophobic agent is dicyclohexano-18-crown ether-6, while all other conditions are the same.

[0077] Comparative Example 3

[0078] Compared with Example 1, Comparative Example 3 differs in that the PCB inkjet printing anti-diffusion agent does not contain a wetting agent, while all other conditions are the same.

[0079] Comparative Example 4

[0080] Compared with Example 1, Comparative Example 4 differs in that the PCB inkjet printing anti-diffusion agent does not contain a stabilizer, while all other conditions are the same.

[0081] Comparative Example 5

[0082] Compared with Example 1, Comparative Example 5 differs in that the anti-diffusion agent for PCB inkjet printing does not contain a co-solvent, but the enterprise conditions are the same.

[0083] Comparative Example 6

[0084] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0085] The composition includes: 0.7% oleophobic agent (composed of 0.4% dicyclohexano-18-crown ether-6 and 0.3% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 3,4-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0086] Comparative Example 7

[0087] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0088] The composition includes: 0.9% oleophobic agent (composed of 0.1% dicyclohexano-18-crown ether-6 and 0.8% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 3,4-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0089] Comparative Example 8

[0090] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0091] The composition includes: 0.4% oleophobic agent (composed of 0.1% dicyclohexano-18-crown ether-6 and 0.3% 5-amino-2-naphthalenesulfonic acid), 2.0% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 3,4-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0092] Comparative Example 9

[0093] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0094] The composition includes: 0.4% oleophobic agent (composed of 0.1% dicyclohexano-18-crown ether-6 and 0.3% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 5.0% stabilizer (methyl 3,4-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0095] Comparative Example 10

[0096] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0097] The composition includes: 0.4% oleophobic agent (composed of 0.1% dicyclohexano-18-crown ether-6 and 0.3% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 3,4-diaminobenzoate), 6.0% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0098] Comparative Example 11

[0099] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0100] The composition includes: 0.3% oleophobic agent (composed of 0.2% dicyclohexano-18-crown ether-6 and 0.1% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 3,4-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0101] Comparative Example 12

[0102] A PCB inkjet printing anti-diffusion agent comprises the following components by weight percentage:

[0103] The composition includes: 0.45% oleophobic agent (composed of 0.05% dicyclohexano-18-crown ether-6 and 0.4% 5-amino-2-naphthalenesulfonic acid), 0.5% wetting agent (3-sulfopropyltetradecyl dimethyl betaine), 1.5% stabilizer (methyl 3,4-diaminobenzoate), 1.5% cosolvent (1-amino-4-piperidinol), and the balance being water.

[0104] Comparative Example 13

[0105] Compared with Example 1, Comparative Example 13 differs in that the dicyclohexano-18-crown ether-6 component in the PCB inkjet printing antidiffusion agent is replaced with an equal mass of cyclohexano-18-crown ether-6 (CAS No.: 17454-53-4), while all other conditions are the same.

[0106] Comparative Example 14

[0107] Compared with Example 1, Comparative Example 14 differs in that the 5-amino-2-naphthalenesulfonic acid component in the PCB inkjet printing anti-diffusion agent is replaced with an equal mass of 2-naphthalenesulfonic acid (CAS No.: 120-18-3), while all other conditions are the same.

[0108] Comparative Example 15

[0109] Comparative Example 15 uses the anti-diffusion liquid from Chinese Patent CN114845474A, wherein the anti-diffusion liquid contains the following components by mass fraction: bonding agent (diepoxyphenyl mercaptan compound) 4.0%; reinforcing agent (1,5-naphthalenedisulfonic acid) 2.0%; wetting agent (3-dodecylbenzene-1,2-diol) 2.5%; accelerator (2,4-thiazolidinedione) 1.5%; and stabilizer (2,4-dihydroxybenzophenone) 2.0%.

[0110] The specific structural formulas of the diepoxyphenyl thiols are as follows:

[0111]

[0112] Performance tests were conducted on the anti-diffusion agents for PCB inkjet printing in Examples 1-6 and Comparative Examples 1-14, as well as the anti-diffusion liquid in Comparative Example 15. The test results are shown in Table 1.

[0113] Table 1. Anti-diffusion agents for PCB inkjet printing in Examples 1-6 and Comparative Examples 1-14

[0114] And the performance test results of the anti-diffusion liquid of Comparative Example 15

[0115]

[0116] Figure 1 This is a real image of the printed circuit board treated with an anti-diffusion agent for inkjet printing according to Embodiment 1 of the present invention, after an ink diffusion test. Figure 2 This is a schematic diagram showing the contact angle test results of the printed circuit board treated with an anti-diffusion agent in PCB inkjet printing according to Embodiment 1 of the present invention. Figure 1-2 As shown in Table 1, the PCB inkjet printing anti-diffusion agent of Examples 1-6 of this invention can effectively prevent ink from spreading on the copper surface and substrate of the circuit board during the printing process. The contact angle test data shows that 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°. The PCB inkjet printing anti-diffusion agent can form an organic layer on the copper surface and substrate surface of the circuit board. This organic layer reacts chemically with the printing ink, strengthening the adhesion between the ink and the copper surface and substrate surface, and preventing the ink from spreading on the copper surface and substrate surface.

[0117] The difference between the anti-diffusion agents for PCB inkjet printing in Comparative Examples 1-5 and Example 1 lies in the absence of a single component from the following components: dicyclohexane crown ether derivative, aminonaphthalene sulfonic acid derivative, wetting agent, stabilizer, and cosolvent. Experimental data shows that the dicyclohexane crown ether derivative and the aminonaphthalene sulfonic acid derivative in the oleophobic agent are the most important active substances in the anti-diffusion agent. Without the dicyclohexane crown ether derivative, slight diffusion occurs on the copper surface, while diffusion on the substrate surface is more severe; without the aminonaphthalene sulfonic acid derivative, diffusion on the copper surface is more severe, while diffusion on the substrate surface is slight. This indicates that the anti-diffusion performance of the PCB inkjet printing anti-diffusion agent of this invention is mainly achieved through the synergistic effect of these two components. The wetting agent, stabilizer, and cosolvent are auxiliary active substances in the PCB inkjet printing anti-diffusion agent. Without any one of these components, the ink contact angle on both the copper and substrate surfaces decreases to varying degrees, resulting in diffusion. This demonstrates that the PCB inkjet printing anti-diffusion agent is the result of the combined action of all effective components.

[0118] The difference between the anti-diffusion agents for PCB inkjet printing in Comparative Examples 6-10 and Example 1 is that the concentrations of dicyclohexane crown ether derivatives, aminonaphthalene sulfonic acid derivatives, wetting agents, stabilizers, and cosolvents in the components exceed the upper limit of the mass percentage concentration range specified in this invention. Experimental data show that, compared to Examples 1-6, the excessively high mass percentage concentrations of dicyclohexane crown ether derivatives and aminonaphthalene sulfonic acid derivatives in the anti-diffusion agents for PCB inkjet printing in Comparative Examples 6-7 cause varying degrees of decrease in the contact angle between the copper surface and the substrate surface, thus leading to diffusion. Therefore, excessive oleophobic agents can actually cause ink diffusion. This is because the polymerization / complexation / coordination bonding between the functional groups (ether, amino, sulfonic acid, alkane, etc.) in the oleophobic agent and the ink, as well as the combined effect of the branched chemical structure of the oleophobic agent, contribute to this diffusion. The contact angle test results of the PCB inkjet printing anti-diffusion agents in Comparative Examples 8-10 show that excessively high mass percentage concentrations of wetting agent, stabilizer, and cosolvent do not significantly affect the contact angle. This indicates that excessively high concentrations of wetting agent, stabilizer, and cosolvent do not affect the effectiveness of the PCB inkjet printing anti-diffusion agent. The surface energy of the organic layer formed and the substrate remains almost unchanged, and the anti-diffusion ability is not enhanced. On the contrary, excessively high concentrations will increase the cost of the solution. Therefore, the mass percentage concentrations of these three components in the PCB inkjet printing anti-diffusion agent of this invention should not be too high. Within the mass percentage concentration range of the embodiments of this invention, the PCB inkjet printing anti-diffusion agent can be guaranteed to stably prevent ink from diffusing on the copper surface and the substrate.

[0119] The difference between the anti-diffusion agent for PCB inkjet printing in Comparative Examples 11-12 and Example 1 is that the mass ratio of the dicyclohexane crown ether derivative to the aminonaphthalene sulfonic acid derivative is lower and higher than the limits specified in this invention, respectively. Experimental data show that if the mass ratio of the dicyclohexane crown ether derivative to the aminonaphthalene sulfonic acid derivative is too low or too high, the ink contact angle on the copper surface and the substrate surface will decrease due to the combined effects of the polymerization / complexation / coordination bonding between the functional groups such as ether, amino, sulfonic acid, and alkane groups in the oleophobic agent and the ink, as well as the side chains of the chemical structure of the oleophobic agent. This will actually reduce the anti-diffusion performance. Therefore, it is necessary to control the mass ratio of the dicyclohexane crown ether derivative to the aminonaphthalene sulfonic acid derivative to be 1:(1.0-4.0).

[0120] The difference between Comparative Example 13 and Example 1 is that dicyclohexano-18-crown ether-6 is replaced with an equal mass of cyclohexano-18-crown ether-6. The difference between Comparative Example 14 and Example 1 is that 5-amino-2-naphthalenesulfonic acid is replaced with an equal mass of 2-naphthalenesulfonic acid. Experimental data show that oleophobic agents with different types of branched groups also affect the anti-diffusion performance. If the oleophobic agent does not contain a dialkylhexyl crown ether or an amino naphthalenesulfonic acid, it will cause severe diffusion of ink on the copper surface and the substrate surface.

[0121] Comparative Example 15 with the PCB inkjet printing anti-diffusion agent of the present invention, Figure 3 This is a real image of the printed circuit board treated with an anti-diffusion agent for inkjet printing, which is Comparative Example 15 of this invention, after an ink diffusion test. Figure 4 This is a schematic diagram showing the contact angle test results of the printed circuit board treated with the anti-diffusion agent in inkjet printing, as described in Comparative Example 15 of this invention. Figures 3-4 Experimental data show that the PCB inkjet printing anti-diffusion agent of this invention has better anti-diffusion performance on the copper surface of the circuit board and the ink on the substrate.

[0122] In summary, the PCB inkjet printing anti-diffusion agent, its preparation method, and its usage method provided by this invention contain effective components such as oleophobic agents, wetting agents, stabilizers, and cosolvents. It can form an organic layer on the copper surface and substrate surface of the circuit board, strengthen the adhesion between the ink and the copper surface and substrate surface, prevent the inkjet ink from diffusing on the copper surface and substrate surface, and improve the product qualification rate of the inkjet solder resist process.

[0123] 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 these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A PCB inkjet printing anti-diffusion agent, characterized in that, Includes the following components by mass percentage: Oleophobic agent 0.15-0.6%, wetting agent 0.2-1.0%, stabilizer 0.5-2.5%, cosolvent 0.1-3.0%, balance water; The oleophobic agent is a mixture of a dicyclohexane crown ether derivative and an aminonaphthalene sulfonic acid derivative; the wetting agent is a betaine derivative; the stabilizer is a diaminobenzoate methyl ester derivative; and the cosolvent is a piperidinol derivative. The dicyclohexane crown ether derivative is present in 0.05-0.2% of the anti-diffusion agent for PCB inkjet printing, and the aminonaphthalene sulfonic acid derivative is present in 0.1-0.4% of the anti-diffusion agent for PCB inkjet printing. The mass ratio of the dicyclohexane crown ether derivative to the aminonaphthalenesulfonic acid derivative is 1:(1.0-4.0).

2. The PCB inkjet printing anti-diffusion agent as described in claim 1, characterized in that, The aforementioned dicyclohexane crown ether derivative is one or more of dicyclohexano-24-crown ether-8 and dicyclohexano-18-crown ether-6.

3. The PCB inkjet printing anti-diffusion agent as described in claim 2, characterized in that, The aminonaphthalenesulfonic acid derivative is one or more of 5-amino-2-naphthalenesulfonic acid and 6-amino-1-naphthalenesulfonic acid.

4. The PCB inkjet printing anti-diffusion agent as described in claim 3, characterized in that, The wetting agent is one or more of 3-sulfopropyltetradecyl dimethyl betaine and citrate betaine.

5. The PCB inkjet printing anti-diffusion agent as described in claim 4, characterized in that, The stabilizer is one or more of methyl 3,4-diaminobenzoate and methyl 2,3-diaminobenzoate.

6. The PCB inkjet printing anti-diffusion agent as described in claim 5, characterized in that, The co-solvent is one or more of 1-amino-4-piperidinol and 1-methyl-4-phenyl-4-piperidinol.

7. The method for preparing the PCB inkjet printing anti-diffusion agent according to any one of claims 1-6, characterized in that, Includes the following steps: Weigh out the oleophobic agent, wetting agent, stabilizer, cosolvent and water in sequence and add them to the reaction vessel. Stir and mix at 23-25℃ for 30-40 minutes to obtain the PCB inkjet printing anti-diffusion agent.

8. The method of using the PCB inkjet printing anti-diffusion agent as described in any one of claims 1-6, characterized in that, Includes the following steps: The PCB was surface-treated using an anti-diffusion agent for inkjet printing. The surface treatment temperature was 25±5℃, the surface treatment line speed was 4.0±0.3m / min, and the surface treatment method was immersion.

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