A water-based liquid photosensitive ink and its preparation method

Abstract

This application relates to the field of functional inks, specifically disclosing a water-based liquid photosensitive ink and its preparation method. The water-based liquid photosensitive ink is prepared from the following raw materials in weight percentages: 40-60% water-based photosensitive resin, 10-20% powder filler, 10-20% photosensitive solvent, 5-10% photosensitizer, 1-3% stabilizer, 0.5-2% colorant, 0.05-0.2% defoamer, and the balance water. The water-based photosensitive resin is mainly composed of acrylic resin, glycidyl methacrylate, and a thickener. The preparation method involves mixing the raw materials, grinding them to a fineness of less than 5µm, and adding water while stirring until homogeneous. The preparation method of this application is simple, and the resulting water-based liquid photosensitive ink exhibits good dispersion and flowability on circuit boards, good adhesion stability, and the cured circuit patterns are not easily deformed or shrunk. The resulting circuit boards have smooth edges, are burr-free, and have a high yield rate.

Description

Technical Field

[0001] This application relates to the field of functional inks, and more specifically, to an aqueous liquid photosensitive ink and a method for preparing the same. Background Technology

[0002] Printed circuit boards (PCBs) are used for electrical connections between electronic components. The manufacturing process of PCBs typically involves laminating a photosensitive film onto the surface of the PCB substrate, followed by processes such as exposure, development, etching, film removal, and electroplating to form the circuit board.

[0003] With the rapid development of the electronics industry and the continuous advancement of chip technology, circuit board manufacturing processes are evolving towards higher precision, thinner profiles, and greater functionality. LDI (Laser Direct Imaging) technology is used in the exposure process of circuit board manufacturing. LDI technology achieves pattern transfer by directly irradiating a PCB substrate coated with photosensitive ink using a laser. Compared to traditional film contact exposure technology, it offers advantages such as precise alignment and the ability to automate the process, eliminating the need for film handling in traditional exposure processes and saving time and costs associated with film loading and unloading. Currently, LDI technology is gradually replacing traditional film contact exposure technology.

[0004] Photosensitive inks, as an indispensable part of LDI technology, need to possess characteristics such as high photosensitivity, stable performance, and easy curing into films. Currently, most photosensitive inks on the market are solvent-based. Solvent-based photosensitive inks have good adhesion and casting properties, but they are less environmentally friendly. Therefore, some photosensitive inks use water-based systems instead of solvent-based ones. However, these water-based photosensitive inks are not easy to cast into a uniform photosensitive film on PCB substrates, reducing the protective performance of the PCB substrate. The printed circuit boards are prone to unevenness and burrs at the circuit edges, resulting in a low yield rate. Summary of the Invention

[0005] To address the problem that water-based photosensitive inks are difficult to cast onto PCB substrates to form a uniform photosensitive film, which reduces the protective performance of the PCB substrate and causes unevenness and burrs on the circuit edges of the printed circuit boards, this application provides a water-based liquid photosensitive ink and its preparation method.

[0006] In a first aspect, this application provides an aqueous liquid photosensitive ink, which adopts the following technical solution:

[0007] A water-based liquid photosensitive ink is prepared from the following raw materials by weight percentage:

[0008] Water-based photosensitive resin 40-60%

[0009] Powder filler 10-20%

[0010] Photosensitive solvent 10-20%

[0011] Photosensitizer 5-10%

[0012] stabilizer 1-3%

[0013] Pigment 0.5-2%

[0014] Defoamer 0.05-0.2%

[0015] Water balance;

[0016] The aqueous photosensitive resin is mainly made of acrylic resin, glycidyl methacrylate and tackifier.

[0017] By adopting the above technical solution, the water-based liquid photosensitive ink of this application uses water-based photosensitive resin as the main resin. It is prepared by reacting acrylic resin and glycidyl methacrylate and compounding with a thickener. The water-based photosensitive resin prepared in this way has good system stability, which can improve the dispersion uniformity of powder fillers in the prepared water-based liquid photosensitive ink system, and at the same time improve the mixing uniformity of other components. This results in good dispersion uniformity and castability of water-based liquid photosensitive ink on circuit boards, and good protection for circuit boards. After curing, a uniformly adhered photosensitive ink layer is formed, which is conducive to exposure by LDI exposure machine. The circuit pattern of the circuit board is formed on the photosensitive ink layer. After processing such as development, etching, stripping and electroplating, the circuit edges of the finished circuit board are smooth and burr-free.

[0018] The photosensitive solvent can further polymerize with the water-based photosensitive resin under the action of the photosensitizer, thereby curing to form a stable photosensitive ink layer.

[0019] Powder fillers enhance the film-forming stability of water-based liquid photosensitive inks, facilitating exposure in LDI exposure machines to form circuit patterns and increasing the strength of the cured photosensitive ink layer. However, the addition of powder fillers can easily lead to uneven dispersion. In contrast, the combined action of water-based photosensitive resin and stabilizers allows for uniform dispersion and casting of powder fillers, resulting in circuit patterns that are easy to form, have good density, and are less prone to shrinkage and deformation during exposure. This, in turn, improves the smoothness of the circuit edges of the manufactured circuit board and reduces burrs.

[0020] Color-changing photosensitive powder can absorb a certain wavelength of ultraviolet light and change color during the exposure treatment of PCB boards, thereby protecting the PCB boards and reducing damage to the PCB boards from ultraviolet radiation; defoamer plays a role in defoaming, improving the coating stability and film uniformity of water-based liquid photosensitive inks.

[0021] Preferably, the aqueous photosensitive resin is prepared from the following raw materials by weight percentage:

[0022] 30-50% acrylic resin

[0023] Glycidyl methacrylate 10-16%

[0024] 25-30% cosolvent

[0025] Tackifier 4-8%

[0026] Catalyst 0.1-0.3%

[0027] Polymerization inhibitor 0.05-0.15%

[0028] Water balance;

[0029] The cosolvent is at least one of ethylene glycol butyl ether, propylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol butyl ether acetate, and propylene glycol butyl ether; the polymerization inhibitor is p-hydroxyanisole and / or hydroquinone; and the catalyst is any one of triphenylphosphine, triethylamine, triethylenediamine, and N,N,N',N'-tetraethylmethylenediamine.

[0030] By employing the above technical solution, the cosolvent and water dissolve the acrylic resin, and under the action of the catalyst and polymerization inhibitor, the acrylic resin and glycidyl methacrylate undergo a polymerization reaction. The addition of a tackifier further enhances the polymerization stability and efficiency of the acrylic resin and glycidyl methacrylate. The resulting water-based photosensitive resin possesses a stable cross-linked structure, improving the dispersion uniformity of the powder filler. The resulting water-based liquid photosensitive ink exhibits good flowability and adhesion stability, while reducing shrinkage and deformation of exposed circuit patterns and improving the burrs and unevenness at the edges of the circuit board.

[0031] Preferably, the thickener is composed of allyl alcohol glycidyl ether and polyoxyethylene 40 hydrogenated castor oil in a weight ratio of 1:(0.2-0.6).

[0032] By adopting the above technical solution, allyl alcohol glycidyl ether can further undergo polymerization with acrylic resin and glycidyl methacrylate; polyoxyethylene 40 hydrogenated castor oil contains hydrophilic and hydrophobic groups, which can further improve the solubility uniformity of acrylic resin, glycidyl methacrylate, and allyl alcohol glycidyl ether in water and cosolvents, thus playing a better role in dispersion and emulsification. Using allyl alcohol glycidyl ether and polyoxyethylene 40 hydrogenated castor oil in a preferred ratio as tackifiers can further improve the stability of the molecular crosslinking structure of the prepared water-based photosensitive resin, improve the flowability and dispersion uniformity of the prepared water-based liquid photosensitive ink system, and reduce the unevenness and burrs on the circuit edges of the prepared circuit board.

[0033] Preferably, the aqueous photosensitive resin is prepared by the following steps:

[0034] A1. Mix water and co-solvent evenly according to weight percentage, then add acrylic resin, mix and stir to dissolve, adjust pH to 7.8-8.8 to obtain acrylic resin solution;

[0035] A2. Add glycidyl methacrylate, tackifier, catalyst and polymerization inhibitor to acrylic resin solution, and react at 85-95℃ for 6-8 hours to obtain water-sensitive photosensitive resin.

[0036] By adopting the above technical solution, the acrylic resin is first dissolved in water and a co-solvent. By adjusting the pH to 7.8-8.8, the solubility of the acrylic resin can be further improved, thereby forming a stable acrylic resin solution. Then, glycidyl methacrylate, thickener, catalyst and polymerization inhibitor are added to react and thus obtain a stable water-based photosensitive resin.

[0037] Preferably, the powder filler is talc and / or barium sulfate, and the particle size of the powder filler is 8000-12000 mesh.

[0038] By adopting the above technical solution, the powder filler has good dispersion and reinforcing properties, which can improve the strength and film-forming stability of the cured photosensitive ink layer and enhance the protection of the circuit board.

[0039] Preferably, the photosensitive solvent is any one or a combination of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and pentaerythritol triacrylate.

[0040] By adopting the above technical solution, the above photosensitive solvents are all multifunctional photosensitive monomers, which can fully crosslink with water-based photosensitive resins, thereby improving the film-forming stability of the prepared water-based photosensitive ink.

[0041] Preferably, the photosensitizer is any one or a combination of photosensitizer TPO, photosensitizer 819, photosensitizer 784, photosensitizer ITX, and photosensitizer BCIM.

[0042] By adopting the above technical solution, ultraviolet rays of a certain wavelength can be absorbed in the exposure process to trigger the polymerization, cross-linking and grafting reaction between the photosensitive monomer and the water-based acrylic resin. The photocuring speed is relatively fast, which allows the water-based photosensitive ink to be cured into a three-dimensional network structure of polymer in a short time. A photosensitive ink layer is formed on the surface of the circuit board and is not easily deformed or shrunk.

[0043] Preferably, the stabilizer is composed of a maleic acid-acrylic acid copolymer and a long-chain alkylsilane coupling agent in a weight ratio of 1:(0.4-1).

[0044] By adopting the above technical solution, the maleic acid-acrylic acid copolymer exhibits good dispersion stability and can improve the dispersion uniformity of the system. Long-chain alkyl silane coupling agents can further enhance the dispersion uniformity of the powder filler and the system. Long-chain alkyl silane coupling agents refer to silane coupling agents with at least twelve straight-chain alkyl groups; commonly used ones include dodecyltrimethoxysilane, hexadecyltrimethoxysilane, and octadecyltrimethoxysilane. Under the action of the maleic acid-acrylic acid copolymer, the molecular segments of the long-chain alkyl silane coupling agent are fully extended, and these segments further intertwine with the molecular segments of the aqueous photosensitive resin. This results in the powder filler being uniformly dispersed in the system, making the cured photosensitive resin layer less prone to shrinkage and deformation, further reducing the problems of unevenness and burrs on the circuit edges of the circuit board.

[0045] Preferably, the viscosity of the aqueous liquid photosensitive ink is 120-320 mPa·s.

[0046] By adopting the above technical solution, water-based liquid photosensitive inks with superior viscosity are easy to process and store, have good storage stability, and are less prone to separation.

[0047] Secondly, this application provides a method for preparing an aqueous liquid photosensitive ink, which adopts the following technical solution: A method for preparing an aqueous liquid photosensitive ink includes the following steps: mixing aqueous photosensitive resin, powder filler, photosensitive solvent, photosensitizer, stabilizer, color powder and defoamer evenly, letting stand, then grinding with a grinding device until the fineness is less than 5μm, then adding water and stirring evenly to obtain an aqueous liquid photosensitive ink.

[0048] By adopting the above technical solution, the preparation method of this application is simple and easy to operate. After the raw materials are mixed evenly, they are ground to reduce the fineness of the ink and improve the fluidity of the ink. At the same time, the particles in the ink are evenly and fully dispersed, improving the coating uniformity and thus improving the film stability.

[0049] In summary, this application has the following beneficial effects:

[0050] 1. The water-based liquid photosensitive ink of this application uses water-based photosensitive resin as the main resin. It is prepared by reacting acrylic resin and glycidyl methacrylate and compounding with a thickener. The water-based photosensitive resin prepared in this way has good system stability, which can improve the dispersion uniformity of powder fillers in the prepared water-based liquid photosensitive ink system, and at the same time improve the mixing uniformity of other components. This makes the water-based liquid photosensitive ink have good dispersion uniformity and casting properties on the circuit board. The circuit pattern formed is not easy to shrink and deform, and has a good protective effect on the circuit board. After curing, a uniformly adhered photosensitive ink layer is formed. After the circuit pattern is processed by development, etching, stripping and electroplating, the circuit edge of the finished circuit board is smooth and free of burrs.

[0051] 2. By using a better ratio of allyl alcohol glycidyl ether and polyoxyethylene 40 hydrogenated castor oil as tackifiers, the stability of the molecular cross-linking structure of the prepared water-based photosensitive resin can be further improved, the flowability and dispersion uniformity of the prepared water-based liquid photosensitive ink system can be improved, and the unevenness and burrs of the circuit edges of the prepared circuit board can be reduced.

[0052] 3. By using a better ratio of maleic acid-acrylic acid copolymer and long-chain alkylsilane coupling agent as stabilizers, a better synergistic effect can be achieved with the water-based photosensitive resin, further improving the performance of the prepared water-based liquid photosensitive resin and improving the unevenness and burr problems of the circuit edges of the prepared circuit board. Detailed Implementation

[0053] The present application will be further described in detail below with reference to the embodiments.

[0054] The following are the sources and parameters of some of the raw materials used in this application. The raw materials used in the preparation examples and embodiments of this application can all be obtained commercially. In the actual production process, the source of raw materials is not limited to the following manufacturers or models, and raw materials with equivalent performance can be used:

[0055] 1. Acrylic resin: DSM Lycon solid acrylic resin NeoCryel B-814;

[0056] 2. Polyoxyethylene 40 hydrogenated castor oil: hydroxyl value 150-165, viscosity 0.16-0.48 Pa·s / 20℃, 1% aqueous solution pH=5.5-7.5;

[0057] 3. Talc: Industrial grade, silica content 60%, 8000-12000 mesh;

[0058] 4. Maleic acid-acrylic acid copolymer: CAS No. 26677-99-6, content 99%, molecular weight 582.

[0059] Preparation example of water-based photosensitive resin

[0060] Preparation Example 1

[0061] Preparation Example 1 discloses a water-based photosensitive resin, which is prepared by the following steps:

[0062] A1. Mix 2.055 kg of water and 2.5 kg of ethylene glycol butyl ether as a co-solvent, then add 3 kg of acrylic resin and stir for 1 hour at a stirring speed of 500 r / min until the acrylic resin is completely dissolved. Then add an alkaline adjuster to adjust the pH to 7.8 to obtain an acrylic resin solution.

[0063] A2. Add 1.6 kg glycidyl methacrylate, 0.8 kg allyl alcohol glycidyl ether as a thickener, 0.03 kg triphenylphosphine as a catalyst and 0.015 kg p-hydroxyanisole as a polymerization inhibitor to the acrylic resin solution prepared above, and react at 85°C for 6 h to obtain a water-based photosensitive resin.

[0064] The alkalinity regulator can be ammonia, triethylamine, or diethylenetriamine. In this example, triethylamine is used, and the amount added is adjusted according to the required pH value.

[0065] Preparation Example 2

[0066] The difference between Preparation Example 2-3 and Preparation Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 1 below.

[0067] Table 1. Raw material amounts and preparation conditions for preparation examples 1-3

[0068]

[0069]

[0070] Preparation Example 4

[0071] The difference between Preparation Example 4 and Preparation Example 1 is that the thickener is different. The thickener in Preparation Example 4 is composed of allyl alcohol glycidyl ether and polyoxyethylene 40 hydrogenated castor oil. The amount of allyl alcohol glycidyl ether is 0.667 kg and the amount of polyoxyethylene 40 hydrogenated castor oil is 0.133 kg. Everything else is the same as in Preparation Example 1.

[0072] Preparation Example 5

[0073] The difference between Preparation Example 5 and Preparation Example 4 is that the amount of allyl alcohol glycidyl ether used is 0.5 kg and the amount of polyoxyethylene 40 hydrogenated castor oil used is 0.3 kg, while the rest is the same as Preparation Example 4.

[0074] Preparation Example 6

[0075] The difference between Preparation Example 6 and Preparation Example 5 is that the polyoxyethylene 40 hydrogenated castor oil is replaced with an equal amount of stearic acid polyoxyethylene ether SG-50, otherwise the same as Preparation Example 5.

[0076] Preparation of Comparative Example 1

[0077] The difference between Comparative Example 1 and Preparation Example 5 is that the tackifier was replaced with an equal amount of acrylic resin, while the rest was the same as Preparation Example 1.

[0078] Example

[0079] Example 1

[0080] Example 1 discloses an aqueous liquid photosensitive ink, which is prepared by the following steps:

[0081] 4 kg of the aqueous photosensitive resin prepared in Preparation Example 1, 2 kg of 8000 mesh talc powder as powder filler, a photosensitive solvent composed of 1.6 kg of trimethylolpropane triacrylate and 0.4 kg of dipentaerythritol hexaacrylate, a photosensitizer composed of 0.5 kg of TPO photosensitizer and 0.5 kg of photosensitizer 819, 0.1 kg of dodecyltrimethoxysilane as stabilizer, 0.05 kg of photosensitive color-changing powder, and 0.005 kg of silicone defoamer were mixed for 30 min at a stirring rate of 300 r / min. After uniform mixing, the mixture was allowed to stand, and then ground with a three-roll mill at a grinding rate of 100 r / min until the fineness was less than 5 μm. Then, 0.845 kg of water was added, and the mixture was mixed for 10 min at a stirring rate of 300 r / min to obtain an aqueous liquid photosensitive ink with a viscosity of 120-320 mPa·s.

[0082] The defoamer is an organosilicon defoamer, Dow Corning AFE-1520; the colorant is a photosensitive colorant, with no limit on model or color. In this embodiment, Runba brand GS4010 is used.

[0083] Example 2

[0084] The difference between Examples 2-3 and Example 1 is that the amount of raw materials used and the preparation conditions are different, and the source of the aqueous photosensitive resin is also different, as detailed in Table 2 below.

[0085] Table 2. Raw material dosage, preparation conditions, and source of aqueous photosensitive resin for Examples 1-3.

[0086]

[0087]

[0088] Examples 4-6

[0089] The difference between Examples 4-6 and Example 1 is that the source of the aqueous photosensitive resin is different, as detailed in Table 3 below.

[0090] Table 3. Source of aqueous photosensitive resin in Examples 4-6

[0091] Example Water-based photosensitive resin source Example 4 Preparation Example 4 Example 5 Preparation Example 5 Example 6 Preparation Example 6

[0092] Example 7

[0093] The difference between Example 7 and Example 5 is that the stabilizer is different. The stabilizer in Example 7 consists of maleic acid-acrylic acid copolymer and long-chain alkyl silane coupling agent. The amount of maleic acid-acrylic acid copolymer is 0.07 kg, and the amount of long-chain alkyl silane coupling agent is 0.03 kg. Maleic acid-acrylic acid copolymer: CAS No. 26677-99-6, solid content 50%. Long-chain alkyl silane coupling agent is dodecyltrimethoxysilane. Other aspects are the same as in Example 5.

[0094] Example 8

[0095] The difference between Example 8 and Example 7 is that the amount of maleic acid-acrylic acid copolymer used is 0.05 kg, and the amount of long-chain alkylsilane coupling agent used is 0.05 kg, while the rest is the same as in Example 7.

[0096] Example 9

[0097] The difference between Example 9 and Example 7 is that maleic acid-acrylic acid copolymer is replaced with an equal amount of polyacrylamide, the molecular weight of which is 3 million. Otherwise, they are the same as in Example 7.

[0098] Comparative Example

[0099] Comparative Example 1

[0100] The difference between Comparative Example 1 and Example 1 is that the aqueous photosensitive resin was derived from the preparation of Comparative Example 1, while the rest is the same as Example 1.

[0101] Comparative Example 2

[0102] The difference between Comparative Example 2 and Example 1 is that the water-based photosensitive resin was replaced in equal amounts with a commercially available water-based acrylic resin, namely DSM Lycon NeoCryL XK-61 water-based acrylic resin. Otherwise, they are the same as in Example 1.

[0103] Comparative Example 3

[0104] The difference between Comparative Example 3 and Example 1 is that the stabilizer was replaced with an equal amount of water-based photosensitive resin, while the rest was the same as Example 1.

[0105] Comparative Example 4

[0106] The difference between Comparative Example 4 and Example 1 is that the amount of aqueous photosensitive resin used is 3.6 kg and the amount of stabilizer used is 0.5 kg, while the rest is the same as in Example 1.

[0107] Performance testing

[0108] The performance of the aqueous liquid photosensitive inks prepared in Examples 1-9 and Comparative Examples 1-4 was tested below:

[0109] (1) Adhesion test

[0110] The aqueous liquid photosensitive inks prepared in Examples 1-9 and Comparative Examples 1-4 were diluted with deionized water at a weight ratio of 4:1 to 25 g / m 2 The coating amount was applied to the copper plate, and it was first dried at 75℃ for 10 minutes. Then, an exposure scale with 21 divisions was used at an energy of 120mJ / cm². 2 The photosensitive ink layer is formed by exposure treatment under certain conditions. Then, the adhesion of the photosensitive ink layer to the surface of the copper plate is tested using the cross-cut adhesion test method, and the test results are recorded.

[0111] (2) Circuit board finished product testing

[0112] The aqueous liquid photosensitive inks prepared in Examples 1-9 and Comparative Examples 1-4 were diluted with deionized water at a weight ratio of 4:1 to 25 g / m 2 The coating was applied to a copper plate and dried at 75°C for 10 minutes; then, an exposure scale with 21 divisions was used at an energy of 120 mJ / cm². 2 Exposure was performed under the following conditions to form a photosensitive ink layer; then, a 1wt% sodium carbonate aqueous solution was used as the developer for development, with a development time of 30 seconds, a developer temperature of 30℃, and a development spray pressure of 1.8 kg / cm². 2 After development, the spray pressure is 1.8 kg / cm². 2The circuit board was washed with water for 20 seconds under the following conditions: etching was then performed using a copper chloride / hydrochloric acid solution at a temperature of 45°C and a etching time of 5 minutes. The copper chloride / hydrochloric acid solution was prepared from the following raw materials by weight percentage: 1% copper chloride, 10% hydrochloric acid, and 89% water. Afterward, a 5 wt% sodium hydroxide aqueous solution was used for deinking at a temperature of 50°C for 2 minutes to obtain the circuit board. The presence or absence of photosensitive ink layer peeling after etching was recorded. The circuit board was then observed under a microscope to check the smoothness and burr condition of the circuit edges, and the test results were recorded.

[0113] The following are the performance test data of the water-based liquid photosensitive inks prepared in Examples 1-9 and Comparative Examples 1-4, as detailed in Table 4 below.

[0114] Table 4. Data on the aqueous liquid photosensitive inks of Examples 1-9 and Comparative Examples 1-4

[0115]

[0116]

[0117] Based on Examples 1-3 and 4-6, Comparative Examples 1-2, and Table 4, it can be seen that the aqueous photosensitive resin prepared in this application, when used in the aqueous liquid photosensitive ink of this application, exhibits good flowability, dispersion, and film-forming properties. The cured photosensitive ink layer shows good adhesion to the circuit board. After exposure, development, and etching processes, the adhesion stability of the photosensitive ink layer is good, providing good protection for the circuit board. The resulting circuit board has smooth circuit edges without burrs, improving the yield of the finished circuit board. In Examples 1-3 and 6, the preferred proportion of tackifier was not used, and a small portion of the cured photosensitive ink layer peeled off after etching, increasing the burrs on the circuit edges of the resulting circuit board. This indicates that the preferred proportion of tackifier in this application can improve the flowability and dispersion uniformity of the prepared aqueous liquid photosensitive ink and improve the burr problem.

[0118] As can be seen from Examples 1-5 and 7-9, Comparative Examples 3-4, and Table 4, the stabilizer of this application can further improve the burr condition of the circuit edges of the prepared circuit board and enhance its smoothness. In Comparative Example 3, the stabilizer was replaced with an equal amount of water-sensitive photosensitive resin. In Comparative Example 4, the stabilizer was increased and the water-sensitive photosensitive resin was decreased. The adhesion of the cured photosensitive ink layer was reduced, and the burrs on the circuit edges of the prepared circuit board increased. This indicates that the optimal amount of stabilizer of this application can produce a better synergistic effect with the water-sensitive photosensitive resin, improve the dispersion uniformity of the powder filler, reduce the problem of shrinkage and deformation of the circuit pattern, enhance the protection of the circuit board, and improve the burr problem.

[0119] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A water-based liquid photosensitive ink, characterized in that, It is made from the following raw materials by weight percentage: Water-based photosensitive resin 40-60% Powder filler 10-20% Photosensitive solvent 10-20% Photosensitizer 5-10% stabilizer 1-3% Pigment 0.5-2% Defoamer 0.05-0.2% Water balance; The aqueous photosensitive resin is prepared from the following raw materials in weight percentages: 30-50% acrylic resin Glycidyl methacrylate 10-16% 25-30% cosolvent Tackifier 4-8% Catalyst 0.1-0.3% Polymerization inhibitor 0.05-0.15% Water balance; The cosolvent is at least one of ethylene glycol butyl ether, propylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol butyl ether acetate, and propylene glycol butyl ether; the polymerization inhibitor is p-hydroxyanisole and / or hydroquinone; the catalyst is any one of triphenylphosphine, triethylamine, triethylenediamine, and N,N,N',N'tetraethylmethylenediamine; the tackifier is composed of allyl glycol glycidyl ether and polyoxyethylene 40 hydrogenated castor oil in a weight ratio of 1:(0.2-0.6); the stabilizer is composed of maleic acid-acrylic acid copolymer and long-chain alkylsilane coupling agent in a weight ratio of 1:(0.4-1).

2. The aqueous liquid photosensitive ink according to claim 1, characterized in that, The aqueous photosensitive resin is prepared by the following steps: A1. Mix water and co-solvent evenly according to weight percentage, then add acrylic resin, mix and stir to dissolve, adjust pH to 7.8-8.8 to obtain acrylic resin solution; A2. Add glycidyl methacrylate, tackifier, catalyst and polymerization inhibitor to acrylic resin solution, and react at 85-95℃ for 6-8 hours to obtain water-sensitive photosensitive resin.

3. The aqueous liquid photosensitive ink according to claim 1, characterized in that, The powder filler is talc and / or barium sulfate, and the particle size of the powder filler is 8000-12000 mesh.

4. The aqueous liquid photosensitive ink according to claim 1, characterized in that, The photosensitive solvent is any one or a combination of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and pentaerythritol triacrylate.

5. The aqueous liquid photosensitive ink according to claim 1, characterized in that, The photosensitizer is any one or a combination of photosensitizers TPO, 819, 784, ITX, and BCIM.

6. The aqueous liquid photosensitive ink according to any one of claims 1-5, characterized in that, The viscosity of the aqueous liquid photosensitive ink is 120-320 mPa·s.

7. A method for preparing an aqueous liquid photosensitive ink as described in any one of claims 1-6, characterized in that, Includes the following steps: The aqueous photosensitive resin, powder filler, photosensitive solvent, photosensitizer, stabilizer, colorant and defoamer are mixed evenly, allowed to stand, and then ground with a grinding equipment until the fineness is less than 5µm. Water is then added and stirred evenly to obtain the aqueous liquid photosensitive ink.

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