A phenoxy resin-based resist dry film and a method for manufacturing the same

Abstract

This invention provides a selective dry film based on phenoxy resin and its preparation method. The selective dry film based on phenoxy resin comprises the following components in parts by weight: 20-50 parts acrylic resin, 2-6 parts phenoxy resin, 5-10 parts acrylate monomer, 5-10 parts phenoxy resin modified filler, 0.1-3 parts photoinitiator, 0.1-5 parts additives, and 10-25 parts solvent. The phenoxy resin modified filler is obtained by reacting epoxidized phenoxy resin and amino-modified filler. This invention uses phenoxy resin as a component of the dry film, effectively improving the toughness of the film layer. Simultaneously, the phenoxy resin modifies the filler, enhancing the compatibility between inorganic and organic components. It also further improves the solvent resistance, stability, and toughness of the film layer, endowing the product with excellent performance and promising application prospects.

Description

Technical Field

[0001] This invention relates to the field of selective dry film technology, and in particular to a selective dry film based on phenoxy resin and its preparation method. Background Technology

[0002] Selective chemical dry film is the core pattern transfer medium in the selective chemical gold plating process of printed circuit board (PCB) manufacturing. Its performance directly determines the circuit forming accuracy, soldering reliability, and product lifespan, and it is widely used in high-end electronic fields such as 5G base stations, new energy vehicle electronic control systems, and semiconductor packaging. With the miniaturization and high density of electronic devices, higher requirements are placed on the toughness, thermal conductivity, insulation, and filler dispersibility of selective chemical dry film. Existing technologies still have many shortcomings that need to be addressed.

[0003] Currently, most dry films on the market use epoxy resin as the main resin. Although they possess certain insulation and processability, their toughness is poor. During lamination, exposure, development, and subsequent processing, they are prone to cracking and delamination due to mechanical stress, leading to defects such as circuit deviation and plating defects, increasing production costs. Meanwhile, to improve the thermal conductivity and insulation properties of dry films, boron nitride is often added as an inorganic filler. It has excellent thermal conductivity and electrical insulation, making it an ideal functional filler. However, boron nitride has poor compatibility with organic resin matrices and is prone to agglomeration. This not only fails to fully realize its functional advantages but also further reduces the mechanical properties of the dry film.

[0004] In existing technologies, silane coupling agents are often used to modify the surface of boron nitride. While this can improve dispersibility to some extent, it suffers from problems such as uneven distribution of the modifier and low reaction efficiency. Furthermore, it may increase interfacial thermal resistance, affecting thermal conductivity and thermal stability. In addition, to address the issue of insufficient dry film toughness, the addition of conventional toughening agents easily leads to a decrease in the heat resistance and insulation of the dry film, making it difficult to meet multiple performance requirements simultaneously.

[0005] Phenoxy resins possess excellent toughness, adhesion, and compatibility, and can be used as toughening components to improve the mechanical properties of resin systems. However, directly adding phenoxy resins still makes it difficult to improve the compatibility with inorganic fillers, and cannot meet the comprehensive performance requirements of chemical dry films in the high-end electronics field.

[0006] Therefore, it is necessary to provide a new technical solution to overcome the defects existing in the prior art. Summary of the Invention

[0007] Based on this, the present invention provides a selective dry film based on phenoxy resin and its preparation method. The present invention uses phenoxy resin as a component of the dry film, which effectively improves the toughness of the film layer. At the same time, the filler is modified with phenoxy resin, which enhances the compatibility between inorganic and organic components. It is also beneficial to further improve the solvent resistance, stability and toughness of the film layer, giving the product excellent performance and good application prospects.

[0008] One object of the present invention is to provide a selective dry film based on phenoxy resin, wherein the selective dry film based on phenoxy resin comprises the following components in parts by weight: 20-50 parts of acrylic resin 2-6 parts of phenoxy resin 5-10 parts of acrylate monomer 5-10 parts of phenoxy resin modified filler Photoinitiator 0.1-3 parts 0.1-5 parts of additives Solvent 10-25 parts.

[0009] Furthermore, the phenoxy resin modified filler is obtained by reacting epoxidized phenoxy resin and amino-modified filler.

[0010] Furthermore, the amino-modified filler is obtained by reacting an aminosilane coupling agent with a filler.

[0011] Furthermore, the mass ratio of the epoxidized phenoxy resin to the amino-modified filler is (0.5-1):(1-2).

[0012] Furthermore, the additive is selected from one or more of plasticizers, crosslinking agents, leveling agents, pigments, dispersants, curing agents, and antioxidants.

[0013] Furthermore, the filler is selected from one or more of boron nitride, silicon carbide, silicon dioxide, aluminum hydroxide, aluminum oxide, zinc oxide, and talc.

[0014] Another object of the present invention is to provide a method for preparing the above-mentioned selective dry film based on phenoxy resin, wherein the method for preparing the selective dry film based on phenoxy resin includes the following steps: S1. Phenoxy resin, epichlorohydrin and catalyst are mixed, heated and reacted, and then alkali is added to continue the reaction to obtain epoxidized phenoxy resin. S2. Mix amino-modified filler, epoxidized phenoxy resin and catalyst, and heat to react to obtain phenoxy resin modified filler; S3. The phenoxy resin modified filler and other components are mixed, coated onto the substrate, dried, and covered with a protective film to obtain the phenoxy resin-based chemical dry film.

[0015] Furthermore, in step S1, the heating reaction is carried out at a temperature of 100-120°C for 1-3 hours.

[0016] Furthermore, in step S1, the temperature for the continued reaction is 50-70°C, and the time is 1-3 hours.

[0017] Furthermore, in step S2, the heating reaction is carried out at a temperature of 80-100°C for 5-10 hours.

[0018] The present invention has the following beneficial effects: This invention discloses a selective dry film based on phenoxy resin. Phenoxy resin is used as a component, possessing numerous ether bonds, hydroxyl groups, and other functional groups. Its main chain exhibits good flexibility and ductility, effectively improving the toughness of the selective dry film. Simultaneously, this invention also modifies the inorganic filler with epoxidized phenoxy resin. The introduction of phenoxy resin significantly improves the compatibility between the filler and the matrix resin, greatly enhancing the dispersion effect. Furthermore, the numerous hydroxyl and epoxy groups introduced onto the filler surface can further crosslink with components such as acrylic resin and phenoxy resin containing carboxyl and hydroxyl groups through chemical bonds and intermolecular forces, thereby improving the bonding effect between various components. The resulting selective dry film balances toughness and stability, exhibiting excellent overall performance and providing a new approach for the development of PCB dry films. 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] The phenoxy resin used in this embodiment of the invention is HUNTSMAN PKHH.

[0024] In the embodiments of the present invention, the acrylate monomers are trimethylolpropane triacrylate (TMPTA) and polydipentaerythritol hexaacrylate (DPHA) in a mass ratio of 1:1.

[0025] The hexagonal boron nitride in this embodiment of the invention undergoes a hydroxylation treatment, including the following steps: Hexagonal boron nitride was immersed in an aqueous sodium hydroxide solution (concentration 17 wt%) (liquid-to-solid ratio ≥100 mL / g), ultrasonically dispersed for 1 h, and then refluxed and stirred in an oil bath at 110℃ for 24 h. After cooling, the product was obtained by centrifugation, washing, and drying.

[0026] In this embodiment of the invention, the photoinitiator is BCIM.

[0027] The additives in this embodiment of the invention are isopropanol, a leveling agent, and OP-10, with a mass ratio of 1:1.

[0028] The solvent used in the embodiments of the present invention is a divalent ester.

[0029] In the embodiments of this invention, "parts" refers to parts by mass.

[0030] Example 1 A selective dry film based on phenoxy resin, wherein the selective dry film based on phenoxy resin comprises the following components in parts by weight: 25 parts acrylic resin 2.5 parts phenoxy resin 6 parts of acrylate monomer 5.2 parts of phenoxy resin modified filler 0.8 parts of photoinitiator 1 part of auxiliary agent 10 parts solvent; The method for preparing the selective dry film based on phenoxy resin includes the following steps: S1. Mix 10 parts of phenoxy resin, 100 parts of epichlorohydrin and 1 part of tetrabutylammonium bromide, heat to reflux, react for 2 h, cool to 60 °C, add 24 parts of sodium hydroxide aqueous solution (concentration of 30 wt%) dropwise at constant temperature, and continue to react for 2 h. After filtering to remove solid impurities, wash with saturated brine, and finally remove excess epichlorohydrin by vacuum distillation to obtain epoxidized phenoxy resin. S2. Using 90 wt% ethanol-water mixture as solvent, 1 part hexagonal boron nitride and 0.5 parts KH-550 were mixed, heated to reflux, and reacted for 12 h. After filtration, washing and drying, amino-modified filler was obtained. Using N-methylpyrrolidone as a solvent, 1 part of the amino-modified filler, 0.5 parts of epoxidized phenoxy resin and 0.01 parts of 4-dimethylaminopyridine were mixed and reacted at 95°C for 6 h. After filtration and drying, the mixture was ground to a particle size ≤4 μm to obtain the phenoxy resin modified filler. S3. Mix the phenoxy resin modified filler and other components evenly according to the above mass proportions, then coat it onto a PET film substrate, dry it at 80°C, and cover it with a PE protective film to form a sandwich structure, thereby obtaining the phenoxy resin-based chemical dry film (intermediate layer thickness is 20 μm).

[0031] Example 2 A selective dry film based on phenoxy resin, wherein the selective dry film based on phenoxy resin comprises the following components in parts by weight: 35 parts acrylic resin 3.5 parts phenoxy resin 8 parts of acrylate monomer 7 parts of phenoxy resin modified filler 1 part photoinitiator 1.5 parts of additives 15 parts solvent; The method for preparing the selective dry film based on phenoxy resin includes the following steps: S1. Mix 10 parts of phenoxy resin, 100 parts of epichlorohydrin and 1 part of tetrabutylammonium bromide, heat to reflux, react for 2 h, cool to 60 °C, add 24 parts of sodium hydroxide aqueous solution (concentration of 30 wt%) dropwise at constant temperature, and continue to react for 2 h. After filtering to remove solid impurities, wash with saturated brine, and finally remove excess epichlorohydrin by vacuum distillation to obtain epoxidized phenoxy resin. S2. Using 90 wt% ethanol-water mixture as solvent, 1 part hexagonal boron nitride and 0.5 parts KH-550 were mixed, heated to reflux, and reacted for 12 h. After filtration, washing and drying, amino-modified filler was obtained. Using N-methylpyrrolidone as a solvent, 1 part of the amino-modified filler, 0.5 parts of epoxidized phenoxy resin and 0.01 parts of 4-dimethylaminopyridine were mixed and reacted at 95°C for 6 h. After filtration and drying, the mixture was ground to a particle size ≤4 μm to obtain the phenoxy resin modified filler. S3. Mix the phenoxy resin modified filler and other components evenly according to the above mass proportions, then coat it onto a PET film substrate, dry it at 80°C, and cover it with a PE protective film to form a sandwich structure, thereby obtaining the phenoxy resin-based chemical dry film (intermediate layer thickness is 20 μm).

[0032] Example 3 A selective dry film based on phenoxy resin, wherein the selective dry film based on phenoxy resin comprises the following components in parts by weight: 45 parts acrylic resin 4.5 parts of phenoxy resin 10 parts of acrylate monomer 8 parts of phenoxy resin modified filler 1.4 parts of photoinitiator 1.5 parts of additives 20 parts solvent; The method for preparing the selective dry film based on phenoxy resin includes the following steps: S1. Mix 10 parts of phenoxy resin, 100 parts of epichlorohydrin and 1 part of tetrabutylammonium bromide, heat to reflux, react for 2 h, cool to 60 °C, add 24 parts of sodium hydroxide aqueous solution (concentration of 30 wt%) dropwise at constant temperature, and continue to react for 2 h. After filtering to remove solid impurities, wash with saturated brine, and finally remove excess epichlorohydrin by vacuum distillation to obtain epoxidized phenoxy resin. S2. Using 90 wt% ethanol-water mixture as solvent, 1 part hexagonal boron nitride and 0.5 parts KH-550 were mixed, heated to reflux, and reacted for 12 h. After filtration, washing and drying, amino-modified filler was obtained. Using N-methylpyrrolidone as a solvent, 1 part of the amino-modified filler, 0.5 parts of epoxidized phenoxy resin and 0.01 parts of 4-dimethylaminopyridine were mixed and reacted at 95°C for 6 h. After filtration and drying, the mixture was ground to a particle size ≤4 μm to obtain the phenoxy resin modified filler. S3. Mix the phenoxy resin modified filler and other components evenly according to the above mass proportions, then coat it onto a PET film substrate, dry it at 80°C, and cover it with a PE protective film to form a sandwich structure, thereby obtaining the phenoxy resin-based chemical dry film (intermediate layer thickness is 20 μm).

[0033] Comparative Example 1 The difference between this comparative example and Example 1 is that step S1 is deleted, and step S2 is modified as follows: Using a 90 wt% ethanol-water mixture as a solvent, 1 part hexagonal boron nitride and 0.5 parts KH-550 were mixed, heated to reflux, and reacted for 12 h. After filtration, washing, and drying, amino-modified filler was obtained. Mix 1 part of the amino-modified filler and 0.5 parts of phenoxy resin, and stir evenly to obtain the phenoxy resin modified filler; The other components and preparation methods are the same as in Example 1.

[0034] Comparative Example 2 The difference between this comparative example and Example 1 is that step S1 is omitted, and the epoxidized phenoxy resin in step S2 is replaced with an equal mass of epoxy resin (E51 epoxy resin); the other components and preparation methods are the same as in Example 1.

[0035] Test case The samples prepared in the examples and comparative examples were subjected to performance tests.

[0036] Test method: The selected dry films prepared in the examples and comparative examples were laminated onto the surface of the copper-clad laminate at 400 mJ / cm². 2 Expose to light, then heat-cur at 150°C for 1 hour.

[0037] Adhesion: Use a needle tip to draw an "X" shape on the film, then stick cellophane tape to the marks and pull it. The evaluation criteria are as follows: √: Not torn off or only a small amount torn off; ×: Tearing off in large quantities.

[0038] 10 mm flexibility: With the selected dry film as the inside, bend it 180° around a cylindrical shaft with a diameter of 10 mm, and evaluate it according to the following criteria: √: No cracks on the film; ×: There are cracks on the film.

[0039] 10 mm flexibility: With the selected dry film as the inside, bend it 180° around a cylindrical shaft with a diameter of 10 mm, and evaluate it according to the following criteria: √: No cracks on the film; ×: There are cracks on the film.

[0040] 8 mm flexibility: With the selected dry film as the inside, bend it 180° around a cylindrical shaft with a diameter of 8 mm, and evaluate it according to the following criteria: √: No cracks on the film; ×: There are cracks on the film.

[0041] 6 mm flexibility: With the selected dry film as the inside, bend it 180° around a cylindrical shaft with a diameter of 6 mm, and evaluate it according to the following criteria: √: No cracks on the film; ×: There are cracks on the film.

[0042] Acid / alkali resistance: At 20°C, the sample is immersed in a 10 wt% sulfuric acid solution or a 10 wt% sodium hydroxide solution for 30 minutes. After immersion, the sample is removed and the coating condition and adhesion are evaluated. The evaluation criteria are as follows: √: No changes or slight changes were found; ×: There is swelling or swelling and peeling on the coating.

[0043] Impact resistance: Copper-clad laminate samples with dry film coating were subjected to a thermal shock test using a thermal shock testing machine, with 1000 cycles of -55℃ / 30 min to 150℃ / 30 min as one cycle. After the test, the coating condition and adhesion were evaluated based on the following criteria: √: Crack initiation rate < 50%; ×: Crack initiation rate ≥ 50%.

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

[0045] Table 1 Performance Test Results As shown in Table 1, the phenoxy resin-based dry film prepared in the embodiments of the present invention exhibits excellent performance, ensuring good adhesion, flexibility, acid and alkali resistance, and impact resistance. In Comparative Example 1, the modified filler was replaced with a mixture of phenoxy resin and aminated filler, resulting in a significantly reduced bonding between components. Obvious cracks appeared during bending, and the film's stability was also reduced, leading to poor impact resistance. Comparative Example 2 used epoxy resin to modify the filler, achieving relatively ideal overall performance. However, the introduced epoxy resin lacked the necessary toughness after curing compared to phenoxy resin, making it difficult to form a flexible toughening network, resulting in a decrease in flexibility compared to 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 selective dry film based on phenoxy resin, characterized in that, The selected dry film based on phenoxy resin comprises the following components in parts by weight: 20-50 parts of acrylic resin 2-6 parts of phenoxy resin 5-10 parts of acrylate monomer 5-10 parts of phenoxy resin modified filler Photoinitiator 0.1-3 parts 0.1-5 parts of additives Solvent 10-25 parts.

2. The selective dry film based on phenoxy resin according to claim 1, characterized in that, The phenoxy resin modified filler is obtained by reacting epoxidized phenoxy resin and amino-modified filler.

3. The selective dry film based on phenoxy resin according to claim 2, characterized in that, The amino-modified filler is obtained by reacting an aminosilane coupling agent with a filler.

4. The selective dry film based on phenoxy resin according to claim 2, characterized in that, The mass ratio of the epoxidized phenoxy resin to the amino-modified filler is (0.5-1):(1-2).

5. The selective dry film based on phenoxy resin according to claim 1, characterized in that, The additives are selected from one or more of plasticizers, crosslinking agents, leveling agents, pigments, dispersants, curing agents, and antioxidants.

6. The method for preparing the selective dry film based on phenoxy resin according to any one of claims 1-5, characterized in that, The method for preparing the selective dry film based on phenoxy resin includes the following steps: S1. Phenoxy resin, epichlorohydrin and catalyst are mixed, heated and reacted, and then alkali is added to continue the reaction to obtain epoxidized phenoxy resin. S2. Mix amino-modified filler, epoxidized phenoxy resin and catalyst, and heat to react to obtain phenoxy resin modified filler; S3. The phenoxy resin modified filler and other components are mixed, coated onto the substrate, dried, and covered with a protective film to obtain the phenoxy resin-based chemical dry film.

7. The method for preparing a selective dry film based on phenoxy resin according to claim 6, characterized in that, In step S1, the heating reaction is carried out at a temperature of 100-120°C for 1-3 hours.

8. The method for preparing a selective dry film based on phenoxy resin according to claim 6, characterized in that, In step S1, the temperature for the continued reaction is 50-70°C, and the time is 1-3 hours.

9. The method for preparing a selective dry film based on phenoxy resin according to claim 6, characterized in that, In step S2, the heating reaction is carried out at a temperature of 80-100℃ for 5-10 hours.

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