Exposure and development type selected ink and method for preparing the same

Abstract

The application provides an exposure and development type selected ink and a preparation method thereof, and the exposure and development type selected ink comprises the following components in mass fractions: 10-20 parts of an acrylic resin, 5-15 parts of carboxyl-containing epoxy acrylate, 10-25 parts of an active monomer, 5-10 parts of a modified filler, 0.1-3 parts of a photoinitiator, and 0.5-5 parts of an auxiliary agent; wherein the modified filler is obtained by the reaction of an aminated filler and alkyl amine and acid anhydride. The carboxyl-containing epoxy acrylate, the modified filler and the like are compounded, synergistic effects among the various components are achieved, the ink is endowed with excellent mechanical toughness, thermal stability and high-precision development forming performance, can meet the large-scale and high-reliability production requirements of high-end high-density PCBs and precision semiconductor devices in the field, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of selective ink technology, and in particular to an exposure and development type selective ink and its preparation method. Background Technology

[0002] Selective photosensitive inks are core photosensitive masking materials in the fields of printed circuit boards, precision electronic components, and semiconductor packaging. They are mainly used in precision processes such as selective gold plating, selective etching, and localized insulation protection in PCB manufacturing. Based on the process principles of ultraviolet exposure crosslinking and alkaline development imaging, they can precisely form customized protective patterns, effectively protecting the substrate and circuitry in non-processed areas. This avoids damage to the circuitry caused by subsequent processes such as immersion gold plating, etching, and micro-etching. They also offer advantages such as strong process adaptability, high pattern accuracy, and controllable cost, making them a key supporting material for achieving high-density, miniaturized electronic circuit processing. As electronic devices iterate towards miniaturization, high density, and high reliability, the line width and spacing of electronic lines continue to shrink. Products need to withstand higher-temperature reflow soldering processes, multiple thermal cycling shocks, and long-term humid and hot aging environments, placing more stringent requirements on the coating mechanical properties, thermal stability, molding integrity, and weather resistance of selective photosensitive inks.

[0003] Currently, the mainstream chemical ink matrix resin in the industry mostly uses bisphenol A type epoxy acrylate. Although it has the advantages of good solvent resistance and corrosion resistance, its molecular structure is extremely rigid and lacks flexible groups in the molecular chain. After cross-linking and curing, the internal stress of the coating film is concentrated, resulting in poor overall toughness, weak impact resistance and bending resistance. In subsequent mechanical processing such as board cutting, bonding, and hot pressing, problems such as coating cracking, peeling and edge flaking are very likely to occur, which cannot meet the requirements of high-temperature processing and long-term reliable use of high-end electronic devices.

[0004] To enhance the overall performance of chemical inks, existing technologies typically incorporate functional fillers. However, conventional inorganic fillers have extremely poor interfacial compatibility with organic resin matrices, making them prone to agglomeration, sedimentation, and stratification in ink systems. This not only fails to provide reinforcement and stabilization but also disrupts coating uniformity, reduces exposure and development resolution, and easily leads to defects such as development residue, jagged edges, and pinholes. Furthermore, conventional fillers lack the function of buffering internal stress in the coating, resulting in negligible improvement in ink toughness and thermal stability.

[0005] Therefore, it is necessary to provide a new technical solution to improve the overall performance of chemical ink products and overcome the defects existing in the prior art. Summary of the Invention

[0006] Based on this, the present invention provides an exposure and development type selective ink and its preparation method. The present invention uses carboxyl-containing epoxy acrylate, modified fillers and other compounding agents to achieve synergistic effects among multiple components, giving the ink excellent mechanical toughness, thermal stability and high-precision development and molding performance. It can meet the needs of large-scale and high-reliability production of high-end high-density PCBs and precision semiconductor devices in the field, and has good application prospects.

[0007] One object of the present invention is to provide an exposure and development type selective ink, the exposure and development type selective ink comprising the following components in parts by weight: 10-20 parts acrylic resin 5-15 parts of carboxyl epoxy acrylate 10-25 parts of active monomer 5-10 parts of modified filler Photoinitiator 0.1-3 parts Additives: 0.5-5 parts; in, The modified filler is obtained by reacting aminated filler with alkylamine and acid anhydride.

[0008] Furthermore, the carboxyl-containing epoxy acrylate is obtained by reacting acid anhydride and bisphenol F epoxy acrylate.

[0009] Furthermore, the alkyl group in the alkylamine is selected from C10-C20 alkyl groups.

[0010] Furthermore, the acid anhydride is a dianhydride.

[0011] Furthermore, the additives are selected from one or more of the following: color powder, leveling agent, defoamer, dispersant, emulsifier, and plasticizer.

[0012] Furthermore, the filler is hexagonal boron nitride.

[0013] Another object of the present invention is to provide a method for preparing the above-mentioned exposure-developing selective ink, the method comprising the following steps: S1. Mix alkylamine and acid anhydride and stir to react, and obtain intermediate product; S2. Mix the aminated filler and intermediate product and heat to react to obtain the modified filler; S3. Mix the modified filler and other components such as acrylic resin evenly, grind and filter to obtain the exposure and development type selective ink.

[0014] Furthermore, in step S1, the temperature of the heating reaction is 20-50°C.

[0015] Furthermore, in step S2, the temperature of the heating reaction is 30-70°C.

[0016] Furthermore, it also includes: Bisphenol F epoxy acrylate and acid anhydride are mixed, a catalyst and a polymerization inhibitor are added, and the mixture is heated to react and obtain carboxyl-containing epoxy acrylate.

[0017] Furthermore, the temperature of the heating reaction is 50-80°C.

[0018] The present invention has the following beneficial effects: This invention discloses a selectively colored ink for exposure and development. First, a modified epoxy acrylate containing carboxyl groups is prepared using bisphenol F epoxy acrylate and acid anhydride as raw materials. This resin has a large number of active groups such as carboxyl groups, resulting in good development performance. It can also form a hydrogen bond network, exhibiting good mechanical strength and adhesion, and contributing to improved thermal stability and corrosion resistance. The selectively colored ink of this invention also contains a modified filler. This filler is obtained by further reacting the product of the reaction between dianhydride and long alkylamine with aminated boron nitride. Introducing various structures such as benzene rings, long alkyl chains, and amide groups into the filler not only improves the compatibility between inorganic components and the main resin, achieving uniform distribution, but also allows cross-linking with carboxyl-containing epoxy acrylate and acrylic resin through intermolecular forces and chemical bonds via amide groups, amino groups, and other functional groups. Furthermore, the benzene rings in the modified filler can combine with the benzene rings in the organic resin through π-π stacking interactions, thereby improving the bonding effect through multiple effects, enhancing the ink's integrity, and promoting improved protective function and mechanical properties. Furthermore, the modified filler combined with the matrix resin also has long alkyl chains, which can introduce flexible segments into the network cross-linked structure of the ink system. Through entanglement, the generation of interface defects can be avoided, and the filler can play a role in buffering, reducing brittleness, and preventing crack propagation. This effectively avoids excessive rigidity of the resin system and greatly improves the toughness of the ink layer. Detailed Implementation

[0019] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0020] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0021] It should be understood that, except in any operational instance or otherwise indicated, all figures representing the amounts of ingredients used, for example, in the specification and claims, should be understood to be modified in all cases by the term "about". Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximations varying with the desired performance to be obtained according to the invention.

[0022] The acrylic resin used in this embodiment of the invention is Sartoma SB520A20.

[0023] In the embodiments of the present invention, the active monomers are trimethylolpropane triacrylate, tripropylene glycol diacrylate and isobornyl acrylate in a mass ratio of 1:0.5:0.5.

[0024] The photoinitiator in this embodiment of the invention is 819.

[0025] In this embodiment of the invention, the leveling agent is isopropanol and the emulsifier is OP-10.

[0026] The preparation method of the carboxyl-containing epoxy acrylate in this embodiment of the invention includes the following steps: L1. Bisphenol F epoxy resin (NPEF-170) and acrylic acid were mixed in a molar ratio of 1:2. Then, the polymerization inhibitor p-hydroxyanisole (0.1% by weight of reactant) and the catalyst N,N-dimethylaniline (1% by weight of reactant) were added. The reaction was carried out under reflux conditions at a constant temperature of 90°C. The reaction was stopped by cooling after the acid value was measured to be lower than 5 mgKOH / g, and bisphenol F epoxy acrylate was obtained. L2. The bisphenol F epoxy acrylate and maleic anhydride are mixed (bisphenol F epoxy resin: maleic anhydride = 1:2, n / n), and then the polymerization inhibitor p-hydroxyanisole (0.1% of the reactant mass) and the catalyst N,N-dimethylaniline (1% of the reactant mass) are added. The mixture is reacted at 80°C for 2 h to obtain carboxyl-containing epoxy acrylate.

[0027] The preparation method of aminated boron nitride in the embodiments of the present invention includes the following steps: Hexagonal boron nitride was immersed in an aqueous sodium hydroxide solution (concentration 17 wt%) (liquid-solid ratio ≥100 mL / g), ultrasonically dispersed for 1 h, and then refluxed and stirred for 24 h under an oil bath at 110℃. After cooling, it was centrifuged, washed, and dried to obtain hydroxylated boron nitride. Using a 90 wt% ethanol-water mixture as a solvent, 1 part of hydroxylated boron nitride and 0.6 parts of KH-550 were mixed, heated to reflux, and reacted for 12 h. After filtration, washing, and drying, aminolated boron nitride was obtained.

[0028] In the embodiments of this invention, "parts" refers to parts by mass.

[0029] Example 1 An exposure and development selective ink, the exposure and development selective ink comprising the following components in parts by weight: 10 parts acrylic resin 8 parts containing carboxyl epoxy acrylate 14 parts of active monomer 5 parts of modified filler 0.8 parts of photoinitiator 0.5 parts leveling agent 0.5 parts emulsifier; The preparation method of the exposure and development type selective ink includes the following steps: S1. Using N,N-dimethylformamide as a solvent, add dodecylamine and pyromellitic dianhydride in a molar ratio of 1:1, stir the mixture at room temperature for 6 h to obtain an intermediate product solution. S2. Add the aminated filler to the intermediate product solution (aminated filler: pyromellitic dianhydride = 5:1, m / m) and stir at 60°C for 10 h. Remove the solvent and dry to obtain the modified filler. S3. Mix the modified filler and the remaining components such as acrylic resin according to the above-mentioned mass proportions, stir evenly, and grind to a fineness of <1 μm to obtain the exposure and development type selective ink.

[0030] Example 2 An exposure and development selective ink, the exposure and development selective ink comprising the following components in parts by weight: 14 parts acrylic resin 11 parts containing carboxyl epoxy acrylate 20 parts of active monomer 7 parts of modified filler 1 part photoinitiator 0.8 parts leveling agent 0.9 parts emulsifier; The preparation method of the exposure and development type selective ink includes the following steps: S1. Using N,N-dimethylformamide as a solvent, tetradecylamine and pyromellitic dianhydride in a molar ratio of 1:1 were added, and the mixture was stirred at room temperature for 6 h to obtain an intermediate product solution. S2. Add the aminated filler to the intermediate product solution (aminated filler: pyromellitic dianhydride = 5:1, m / m) and stir at 60°C for 10 h. Remove the solvent and dry to obtain the modified filler. S3. Mix the modified filler and the remaining components such as acrylic resin according to the above-mentioned mass proportions, stir evenly, and grind to a fineness of <1 μm to obtain the exposure and development type selective ink.

[0031] Example 3 An exposure and development selective ink, the exposure and development selective ink comprising the following components in parts by weight: 18 parts acrylic resin 15 parts containing carboxyl epoxy acrylate 25 parts of active monomer 10 parts of modified filler 1.5 parts photoinitiator 1 part leveling agent 1 part emulsifier; The preparation method of the exposure and development type selective ink includes the following steps: S1. Using N,N-dimethylformamide as a solvent, tetradecylamine and pyromellitic dianhydride in a molar ratio of 1:1 were added, and the mixture was stirred at room temperature for 6 h to obtain an intermediate product solution. S2. Add the aminated filler to the intermediate product solution (aminated filler: pyromellitic dianhydride = 5:1, m / m) and stir at 60°C for 10 h. Remove the solvent and dry to obtain the modified filler. S3. Mix the modified filler and the remaining components such as acrylic resin according to the above-mentioned mass proportions, stir evenly, and grind to a fineness of <1 μm to obtain the exposure and development type selective ink.

[0032] Comparative Example 1 The difference between this comparative example and Example 1 is that in the preparation method of carboxyl-containing epoxy acrylate, bisphenol F epoxy resin is replaced with bisphenol A epoxy resin (E-44), and step L2 is deleted; other components and preparation methods are the same as in Example 1.

[0033] Comparative Example 2 The difference between this comparative example and Example 1 is that steps S1 and S2 are omitted, and an aminated filler is used as the modified filler; the other components and preparation methods are the same as in Example 1.

[0034] Test case The performance of the selected ink samples prepared in the examples and comparative examples was tested.

[0035] Test method: The selected inks prepared in the examples and comparative examples were coated onto PCB boards and cured with light for 0.5 h (wavelength 395 nm, intensity 25.0 mW / cm²). 2 (The film is exposed to ultraviolet light), and then heat-cured at 150°C for 1 hour to form a 0.5 mm thick film.

[0036] Pencil hardness: measured based on JIS K5400.

[0037] Adhesion: Use a needle tip to draw an "X" shape on the film, then apply cellophane tape to the marks and pull it. Evaluate according to the following criteria: Acceptable: Not torn off or only a small amount torn off; Unacceptable: Too many pieces were torn off.

[0038] 10 mm flexibility: With the ink film as the inside, bend 180° around a cylindrical shaft with a diameter of 10 mm, and evaluate according to the following criteria: Pass: No cracks on the film; Unacceptable: The film has cracks.

[0039] 8 mm flexibility: With the ink film as the inside, bend 180° around an 8 mm diameter cylindrical shaft and evaluate according to the following criteria: Pass: No cracks on the film; Unacceptable: The film has cracks.

[0040] 6 mm flexibility: With the ink film as the inside, bend 180° around a cylindrical shaft with a diameter of 6 mm, and evaluate according to the following criteria: Pass: No cracks on the film; Unacceptable: The film has cracks.

[0041] Heat resistance: Thermal shock performance was tested according to the method in IPC-SM-840E, and the judgment criteria are as follows: Pass: No bubbles or cracks; Unacceptable: Bubbles or cracks appear.

[0042] Exposure and Development: Exposure: Substrate: Printed wiring substrate (glass epoxy board "FR-4", board thickness 1.6 mm, conductor (Cu foil) thickness 50 μm). Substrate surface treatment: Ultra-roughening treatment. Coating method: Screen printing. Wet film thickness: 20 μm. Pre-baking: 80℃, 30 min. Irradiation at 300 mJ / cm² after ink coating. 2 Ultraviolet light (wavelength 300-400 nm). Alkali development: 1 wt% Na2CO3 solution, liquid temperature 30℃, jet pressure 0.2 MPa, development time 60 s.

[0043] The resolution of the image is observed under a microscope after exposure and development: Acceptable: After pre-baking, the dry film thickness is 10 μm; after exposure and development, the image resolution, line width, and line spacing are <40 μm. Unacceptable: Graphic resolution, line width, and line spacing > 40 μm.

[0044] The test results are shown in Table 1.

[0045] Table 1 Performance Test Results As shown in Table 1, the exposure and development type selective inks prepared in the embodiments of the present invention exhibit good comprehensive performance in terms of adhesion, flexibility, and thermal stability, meeting the high requirements of the art for the performance of selective inks. Comparative Example 1 uses bisphenol A epoxy acrylate to replace carboxyl-containing epoxy acrylate, resulting in improved hardness but a significant decrease in toughness. Furthermore, due to the reduction in active carboxyl groups, adhesion and exposure and development resolution are not ideal. Comparative Example 2 uses aminated fillers as components; due to the lack of introduction of long alkyl and benzene ring structures, its toughness and resolution both decrease, and its overall performance is lower than that of the embodiments.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0047] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A selectively colored ink for exposure and development, characterized in that, The exposure and development type selective ink comprises the following components in parts by weight: 10-20 parts acrylic resin 5-15 parts of carboxyl epoxy acrylate 10-25 parts of active monomer 5-10 parts of modified filler Photoinitiator 0.1-3 parts Additives: 0.5-5 parts; in, The modified filler is obtained by reacting aminated filler with alkylamine and acid anhydride.

2. The selectively selected exposure and development ink according to claim 1, characterized in that, The carboxyl-containing epoxy acrylate is obtained by reacting acid anhydride and bisphenol F epoxy acrylate.

3. The selectively selected exposure and development ink according to claim 1, characterized in that, The alkyl group in the alkylamine is selected from C10-C20 alkyl groups.

4. The selectively selected exposure and development ink according to claim 1, characterized in that, The acid anhydride is a dianhydride.

5. The selectively selected exposure and development ink according to claim 1, characterized in that, The additives are selected from one or more of the following: color powder, leveling agent, defoamer, dispersant, emulsifier, and plasticizer.

6. The method for preparing the exposure and development type selective ink according to any one of claims 1-5, characterized in that, The preparation method of the exposure and development type selective ink includes the following steps: S1. Mix alkylamine and acid anhydride and stir to react, and obtain intermediate product; S2. Mix the aminated filler and intermediate product and heat to react to obtain the modified filler; S3. Mix the modified filler and other components such as acrylic resin evenly, grind and filter to obtain the exposure and development type selective ink.

7. The method for preparing the exposure and development type selective ink according to claim 6, characterized in that, In step S1, the temperature of the stirring reaction is 20-50℃.

8. The method for preparing the exposure and development type selective ink according to claim 6, characterized in that, In step S2, the temperature of the heating reaction is 30-70℃.

9. The method for preparing the exposure and development type selective ink according to claim 6, characterized in that, Also includes: Bisphenol F epoxy acrylate and acid anhydride are mixed, a catalyst and a polymerization inhibitor are added, and the mixture is heated to react and obtain carboxyl-containing epoxy acrylate.

10. The method for preparing the exposure and development type selective ink according to claim 9, characterized in that, The heating reaction is carried out at a temperature of 50-80℃.

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