Alkali-soluble resin, preparation method thereof and photosensitive dry film resist

Abstract

The invention discloses alkali-soluble resin, a preparation method thereof and a photosensitive dry film resist, and belongs to the technical field of photosensitive dry film resists. The structural formula of the alkali-soluble resin is as shown in formula I in the specification. According to the alkali-soluble resin disclosed by the invention, polymaleic anhydride is modified into polymaleimide, meanwhile, a fluorine-containing group is introduced to an N atom of the polymaleimide, and through the synergistic effect of the polymaleic anhydride and the fluorine-containing group, the electroplating resistance of a photosensitive dry film of the corresponding alkali-soluble resin can be effectively improved; and the diffusion coating or film throwing phenomenon of the photosensitive dry film resist product in the use process is reduced. The fluorine-substituted maleimide polymer can also improve the leveling property of the photosensitive dry film resist in the coating process, reduce the volume shrinkage of the dry film, and further improve the finished product yield of the photosensitive dry film.

Description

Technical Field

[0001] This invention belongs to the field of photosensitive dry film resist technology, specifically relating to an alkali-soluble resin and its preparation method, and a photosensitive dry film resist. Background Technology

[0002] Dry film resists are widely used in the fabrication of printed circuit boards, semiconductor packages, and lead frames. The process involves attaching the dry film resist to a copper substrate, then using a patterned mask to expose the pattern on the resist. The unexposed areas are then cleaned with a weakly alkaline aqueous solution, followed by etching or electroplating to form the desired pattern. Finally, an alkaline stripping solution is used to remove the exposed and cured portions of the dry film, thus achieving pattern transfer.

[0003] There are two main methods for manufacturing printed circuit boards (PCBs): masking and pattern plating. Masking uses a protective layer to protect copper vias used for mounting connectors, followed by etching and film removal to form the circuit. However, with the miniaturization and thinning of electronic devices, PCBs now require high precision and multi-layered designs, demanding high resolution and adhesion from dry film resists. This necessitates the fabrication of fine-pitch patterns, making pattern plating crucial. This involves electroplating copper onto a copper substrate, protecting it with tin solder, and then removing the film and etching to form the circuit. During copper plating, degreasers and tinning agents are used for surface treatment of the copper substrate. These agents can also attack the dry film resist. If the dry film resist has weak electroplating resistance, it can cause uneven deformation of the sidewalls and lifting of the bottom, leading to plating defects and poor circuit patterns.

[0004] Alkali-soluble resins, as a core component of photosensitive dry film resists (accounting for approximately 40%-70% of the dry film mass), significantly influence the developability, adhesion, and electroplating resistance of photosensitive dry film resists. However, currently, there are relatively few types of alkali-soluble resins with good electroplating resistance, and some alkali-soluble resins with good electroplating resistance suffer from poor compatibility with other components, affecting the developability, adhesion, and other properties of photosensitive dry film resists. Therefore, developing an alkali-soluble resin with superior overall performance is an urgent technical problem to be solved. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide an alkali-soluble resin and its preparation method, as well as a photosensitive dry film resist.

[0006] In a first aspect, the present invention provides an alkali-soluble resin with the structural formula shown in Formula I: Wherein, R1 is a hydrogen atom or methyl; R2 is a C0-C6 methylene group; R3 is hydrogen or methyl; R4 is one of a C1-C10 straight-chain alkyl, branched alkyl, or aromatic group; R5 is a monofluorinated or polyfluorinated substituted C1-C10 alkyl or aromatic group; R6 is hydrogen or methyl; a, b, c, and d represent the mass percentage content of each polymerizing monomer, 15%≤a≤25%; 45%≤b≤55%; 15%≤c≤25%; 5%≤d≤15%, a+b+c+d=100%.

[0007] Secondly, the present invention provides a method for preparing an alkali-soluble resin, the synthetic route of which is as follows: Includes the following steps: (1) After mixing monomer 1, monomer 2, monomer 3, monomer 4, the first part of the initiator and the solvent, solution A is obtained; after mixing the second part of the initiator and the solvent, solution B is obtained; the solvent is added to the reactor and the temperature is raised to the reaction temperature, and then solution A is continuously passed into the reactor. After the passage is completed, the reaction is set for a time, and then solution B is added dropwise to the reaction solution. After the dropwise addition is completed, the temperature is raised to continue the reaction, and a reaction solution containing primary alkali soluble resin A is obtained. (2) Under ice bath conditions, a solution containing NH2-R5 was added dropwise to the reaction solution containing primary base soluble resin A. After the addition was completed, the temperature was raised to room temperature to carry out the reaction, and a reaction solution containing intermediate base soluble resin B was obtained. (3) Add sodium acetate and acetic anhydride to the reaction solution containing intermediate alkali-soluble resin B, heat to the set temperature and carry out the reaction. After the reaction is complete, separate and purify to obtain alkali-soluble resin.

[0008] Thirdly, the present invention provides a method for preparing an alkali-soluble resin, the synthetic route of which is as follows: Includes the following steps: (1) Under ice bath conditions, a solution containing NH2-R5 was added dropwise to a solution containing monomer 4. After the addition was complete, the temperature was raised to room temperature to carry out the first stage reaction. After the reaction was complete, the intermediate 1 was obtained by separation and purification. Intermediate 1, sodium acetate and acetic anhydride were mixed and heated to the set temperature to carry out the second stage reaction. After separation and purification, monomer 5 was obtained. (2) After mixing monomer 1, monomer 2, monomer 3, monomer 5, the first part of the initiator and the solvent, solution A is obtained; after mixing the second part of the initiator and the solvent, solution B is obtained; the solvent is added to the reactor and the temperature is raised to the reaction temperature. Then, solution A is continuously introduced into the reactor. After solution A is completely introduced, after the reaction time is set, solution B is added dropwise to the reaction solution. After the addition is completed, the temperature is raised to the set temperature and the reaction continues. After the reaction is completed, the solution is separated and purified to obtain the alkali-soluble resin.

[0009] Fourthly, the present invention provides a photosensitive dry film resist comprising the aforementioned alkali-soluble resin.

[0010] Fifthly, the present invention provides an application of a photosensitive dry film resist in printed circuit boards, lead frames, or semiconductor packaging substrates.

[0011] Compared with the prior art, one or more of the above technical solutions can achieve at least one of the following beneficial effects: In this invention, the alkali-soluble resin contains maleimide monomers, which can improve the rigidity and thermal stability of the entire molecular chain, thereby improving the heat resistance and mechanical strength of the entire alkali-soluble resin. That is, the hardness, volume shrinkage, scratch resistance and wear resistance of the photosensitive dry film are all improved. At the same time, the introduction of the imide ring can also endow the final photosensitive dry film with certain resistance to swelling and strong acids and alkalis.

[0012] This invention modifies the alkali-soluble resin with polymaleic anhydride to polymaleimide, and simultaneously introduces fluorine-containing groups onto the nitrogen atoms of the polymaleimide. The synergistic effect of these two modifications effectively improves the electroplating resistance of the corresponding alkali-soluble resin's photosensitive dry film, reducing the occurrence of plating overflow or film splattering during use. The use of fluorine-substituted maleimide polymers also improves the leveling properties of the photosensitive dry film resist during coating, reduces the dry film volume shrinkage rate, and thus increases the yield of the finished photosensitive dry film. Attached Figure Description

[0013] Figure 1 The Fourier transform infrared spectra of the primary alkali-soluble resin A and alkali-soluble resin A1 prepared in Example 1 of this invention are shown.

[0014] Figure 2 The image shows the proton NMR spectrum of monomer 5 prepared in Example 4 of this invention.

[0015] Figure 3 This is the carbon NMR spectrum of monomer 5 prepared in Example 4 of the present invention.

[0016] Figure 4 The Fourier transform infrared spectrum of monomer 5 and alkali-soluble resin A4 prepared in Example 4 of this invention. Detailed Implementation

[0017] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0018] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0019] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0020] As mentioned above, in a first aspect, the present invention provides an alkali-soluble resin with the structural formula shown in Formula I: Wherein, R1 is a hydrogen atom or a methyl group; R2 is a C0-C6 methylene group; R3 is hydrogen or a methyl group; R4 is a C1-C10 straight-chain alkyl group, a branched alkyl group, or an aromatic group; R5 is a monofluorinated or polyfluorinated substituted C1-C10 alkyl group or an aromatic group; R6 is hydrogen or a methyl group; a, b, c, and d represent the mass percentage content of the corresponding monomers, 15%≤a≤25%; 45%≤b≤55%; 15%≤c≤25%; 5%≤d≤15%, and a+b+c+d=100%.

[0021] Preferably, the alkali-soluble resin has a weight-average molecular weight of 40,000 to 100,000 g / mol and a molecular weight distribution of 1.2 to 4.0.

[0022] Preferably, R5 is a polyfluorinated C1-C10 alkyl group.

[0023] Preferably, the alkali-soluble resin is one or more of formulas (1) to (5): .

[0024] Secondly, the present invention provides a method for preparing an alkali-soluble resin, the synthetic route of which is as follows: Includes the following steps: (1) After mixing monomer 1, monomer 2, monomer 3, monomer 4, the first part of the initiator and the solvent, solution A is obtained; after mixing the second part of the initiator and the solvent, solution B is obtained; the solvent is added to the reactor and the temperature is raised to the reaction temperature, and then solution A is continuously passed into the reactor. After the passage is completed, the reaction is set for a time, and then solution B is added dropwise to the reaction solution. After the dropwise addition is completed, the temperature is raised to continue the reaction, and a reaction solution containing primary alkali soluble resin A is obtained. (2) Under ice bath conditions, a solution containing NH2-R5 was added dropwise to the reaction solution containing primary base soluble resin A. After the addition was completed, the temperature was raised to room temperature to carry out the reaction, and a reaction solution containing intermediate base soluble resin B was obtained. (3) Add sodium acetate and acetic anhydride to the reaction solution containing intermediate alkali-soluble resin B, heat to the set temperature and carry out the reaction. After the reaction is complete, separate and purify to obtain alkali-soluble resin.

[0025] In the preparation method of this invention, maleic anhydride is introduced as a monomer into the monomer of primary alkali-soluble resin A. Then, through the reaction of the anhydride with NH2-R5, nitrogen atoms and fluorine-containing groups are introduced, and after ring closure, fluorinated polymaleimide is obtained. Experimental studies have shown that compared with the method of directly polymerizing fluorinated maleimide (monomer 5) with monomers 1, 2, and 3, the overall performance of the alkali-soluble resin prepared by this method is further improved. This may be because the introduction of fluorine atoms enhances the polymerization activity of fluorinated maleimide, which intensifies the electron deficiency on the olefin of fluorinated maleimide, while the olefin on monomer 3 has an electron-rich structure. Therefore, during the polymerization process, fluorinated maleimide and monomer 3 will undergo alternating polymerization, thereby affecting the anti-electroplating and adhesion properties of the alkali-soluble resin.

[0026] Preferably, in step (1), the monomer 1 is one or more of acrylic acid, methacrylic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 3-methylbut-3-enoic acid, and 4-methyl-4-pentenoic acid.

[0027] Preferably, in step (1), the monomer 2 is one or more of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, tert-butyl acrylate, butyl methacrylate, tert-butyl methacrylate, n-octyl acrylate, isooctyl acrylate, n-octyl methacrylate, isooctyl methacrylate, benzyl acrylate, and benzyl methacrylate.

[0028] Preferably, in step (1), the monomer 4 is one or both of maleic anhydride and citrate anhydride.

[0029] Preferably, in step (1), the mass ratio of monomer 1, monomer 2 and monomer 3 is (15~25):(45~55):(15~25); including but not limited to: 15:55:25, 20:40:20, 25:45:15, 18:52:18, 22:48:17, 25:55:25, 15:45:15, 19:47:22, etc.

[0030] Preferably, in steps (1) and (2), the molar ratio of monomer 4 to NH2-R5 in step (2) is 1:(1.00~1.05); the ratio of the mass of monomer 3 to the total mass of monomer 4 and NH2-R5 is (15~25):(5.5~16.9), including but not limited to: 15:5.5, 20:5.5, 25:5.5, 15:11.2, 20:11.2, 25:11.2, 15:16.9, 20:16.9, 25:16.9, etc.

[0031] By controlling the mass percentage of each monomer, the anti-electroplating performance of alkali-soluble resin can be effectively improved while ensuring that the resin has good photosensitivity, resolution, adhesion, and other properties.

[0032] Preferably, in step (1), the first part of the initiator is 0.1-2% of the total mass of monomer 1, monomer 2, monomer 3 and monomer 4, including but not limited to: 0.1%, 0.5%, 1%, 1.5% and 2%; the second part of the initiator is 0.1-2% of the total mass of monomer 1, monomer 2, monomer 3 and monomer 4, including but not limited to: 0.1%, 0.5%, 1%, 1.5% and 2%.

[0033] Preferably, in step (1), the first initiator and the second initiator are each independently selected from one or more of the following: azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, tert-butyl peroxide, and di-tert-butyl peroxide.

[0034] Preferably, in step (1), the solvent is one or more of dichloromethane, chloroform, acetone, butanone, toluene, ethyl acetate, acetonitrile, xylene, tetrahydrofuran, cyclohexanone, N'N-dimethylformamide, 1,4-dioxane, and propylene glycol methyl ether acetate.

[0035] Preferably, in step (1), the reaction temperature is 60~80℃, including but not limited to: 60℃, 65℃, 70℃, 75℃, 80℃, etc.; solution A is controlled to be introduced in 1~3h, including but not limited to: 1h, 1.5h, 2h, 2.5h, 3h, etc.; the set time is 3~5h, including but not limited to: 3h, 3.5h, 4h, 4.5h, 5h, etc.; solution B is controlled to be added dropwise in 15~45min (including but not limited to: 15min, 25min, 35min, 45min, etc.), and the temperature is raised to 70~90℃ (including but not limited to: 70℃, 75℃, 80℃, 85℃, 90℃, etc.) and the reaction continues for 4~6h, including but not limited to: 4h, 4.5h, 5h, 5.5h, 6h, etc.

[0036] Preferably, in step (2), the NH2-R5 is one or more of 4-fluoroaniline, 3-fluoroaniline, 2,2-difluoroethylamine, 2,2,2-trifluoroethylamine, 2,2,3,3,3-pentafluoropropylamine, 2,2,3,3,4,4,4-heptafluorobutylamine, 1H,1H-perfluoroheptylamine, p-trifluoromethylaniline, m-trifluoromethylaniline, and 3-fluoro-4-trifluorotoluidine.

[0037] Preferably, in step (2), the solvent used for the NH2-R5-containing solution is one or more of dichloromethane, chloroform, acetone, butanone, toluene, ethyl acetate, acetonitrile, xylene, tetrahydrofuran, cyclohexanone, N'N-dimethylformamide, 1,4-dioxane, and propylene glycol methyl ether acetate.

[0038] Preferably, in step (2), the reaction time is 12~24h, including but not limited to: 12h, 13h, 5h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24h, etc.

[0039] Preferably, in step (3), the amount of sodium acetate added is 1 to 14% of the mass of intermediate alkali soluble resin B in step (2), including but not limited to: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, etc.; the amount of acetic anhydride added is 0.5 to 5 times the mass of intermediate alkali soluble resin B in step (2), including but not limited to: 0.5 times, 1 times, 1.5 times, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times, 5 times, etc.

[0040] Preferably, in step (3), the temperature is set to 80~120℃, including but not limited to: 80℃, 90℃, 100℃, 110℃, 120℃, etc.; the reaction time is 12~24h, including but not limited to: 12h, 13h, 5h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24h, etc.

[0041] Thirdly, the present invention provides a method for preparing an alkali-soluble resin, the synthetic route of which is as follows: Includes the following steps: (1) Under ice bath conditions, a solution containing NH2-R5 was added dropwise to a solution containing monomer 4. After the addition was complete, the temperature was raised to room temperature to carry out the first stage reaction. After the reaction was complete, the intermediate 1 was obtained by separation and purification. Intermediate 1, sodium acetate and acetic anhydride were mixed and heated to the set temperature to carry out the second stage reaction. After separation and purification, monomer 5 was obtained. (2) After mixing monomer 1, monomer 2, monomer 3, monomer 5, the first part of the initiator and the solvent, solution A is obtained; after mixing the second part of the initiator and the solvent, solution B is obtained; the solvent is added to the reactor and the temperature is raised to the reaction temperature. Then, solution A is continuously introduced into the reactor. After solution A is completely introduced, after the reaction time is set, solution B is added dropwise to the reaction solution. After the addition is completed, the temperature is raised to the set temperature and the reaction continues. After the reaction is completed, the solution is separated and purified to obtain the alkali-soluble resin.

[0042] Preferably, in step (1), the monomer 4 is one or both of maleic anhydride and citrate anhydride.

[0043] Preferably, in step (1), the NH2-R5 is one or more of 4-fluoroaniline, 3-fluoroaniline, 2,2-difluoroethylamine, 2,2,2-trifluoroethylamine, 2,2,3,3,3-pentafluoropropylamine, 2,2,3,3,4,4,4-heptafluorobutylamine, 1H,1H-perfluoroheptylamine, p-trifluoromethylaniline, m-trifluoromethylaniline, and 3-fluoro-4-trifluorotoluidine.

[0044] Preferably, in step (1), the molar ratio of monomer 4 to NH2-R5 is 1:(1.00~1.05); the amount of sodium acetate added is 50~80% of the mass of intermediate 1, including but not limited to: 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc.; the amount of acetic anhydride added is 10~20 times the mass of intermediate 1, including but not limited to: 10 times, 11 times, 12 times, 13 times, 14 times, 15 times, 16 times, 17 times, 18 times, 19 times, 20 times, etc.

[0045] Preferably, in step (1), the reaction time of the first stage is 8~16h, including but not limited to: 8h, 9h, 10h, 11h, 12h, 13h, 5h, 14h, 15h, 16h, etc.; the set temperature is 80~120℃, including but not limited to: 80℃, 90℃, 100℃, 110℃, 120℃, etc.; the reaction time of the second stage is 6~12h, including but not limited to: 6h, 7h, 8h, 9h, 10h, 11h, 12h, etc.

[0046] Preferably, in step (2), the monomer 1 is one or more of acrylic acid, methacrylic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 3-methylbut-3-enoic acid, and 4-methyl-4-pentenoic acid.

[0047] Preferably, in step (2), the monomer 2 is one or more of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, tert-butyl acrylate, butyl methacrylate, tert-butyl methacrylate, n-octyl acrylate, isooctyl acrylate, n-octyl methacrylate, isooctyl methacrylate, benzyl acrylate, and benzyl methacrylate.

[0048] Preferably, in step (2), the monomers 1, 2, 3, and 5 are in a mass ratio of 15~25:45~55:15~25:5~15, including but not limited to: 15:55:20:10, 20:50:15:15, 25:45:25:5, 22:48:22:8, 19:52:20:9, 18:49:22:11, etc.; the first part of the initiator is 0.1~2% of the total mass of monomers 1, 2, 3, and 5, including but not limited to: 0.1%, 0.5%, 1%, 1.5%, 2%, etc.; the second part of the initiator is 0.1~2% of the total mass of monomers 1, 2, 3, and 5, including but not limited to: 0.1%, 0.5%, 1%, 1.5%, 2%, etc.

[0049] Preferably, in step (2), the first initiator and the second initiator are each independently selected from one or more of the following: azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, tert-butyl peroxide, and di-tert-butyl peroxide.

[0050] Preferably, in step (2), the reaction temperature is 60~80℃, including but not limited to: 60℃, 65℃, 70℃, 75℃, 80℃, etc.; solution A is controlled to be introduced in 1~3h, including but not limited to: 1h, 1.5h, 2h, 2.5h, 3h, etc.; the set time is 3~5h, including but not limited to: 3h, 3.5h, 4h, 4.5h, 5h, etc.; solution B is controlled to be added in 15~45min (including but not limited to: 15min, 25min, 35min, 45min, etc.), the set temperature is 70~90℃ (including but not limited to: 70℃, 75℃, 80℃, 85℃, 90℃, etc.), and the reaction time continues for 4~6h, including but not limited to: 4h, 4.5h, 5h, 5.5h, 6h, etc.

[0051] Fourthly, the present invention provides a photosensitive dry film resist comprising the aforementioned alkali-soluble resin.

[0052] Preferably, the photosensitive dry film resist comprises, by weight parts: Alkali-soluble resin 42-65 parts, including but not limited to: 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts, 58 parts, 60 parts, 62 parts, 65 parts, etc.; Photopolymerizable monomers in quantities of 21 to 48 parts, including but not limited to: 21 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, etc. Photoinitiator 0.1 to 5 parts, including but not limited to: 0.1 parts, 0.5 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.; The auxiliary agent is 0.1 to 5 parts, including but not limited to: 0.1 parts, 0.5 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.

[0053] Preferably, the photopolymerizable monomer is one or more of the following: 1,6-hexanediol acrylate, tripropylene glycol diacrylate, ethoxylated bisphenol A diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, propoxylated glycerol triacrylate, ethoxylated trimethylolpropane triacrylate, and dipentaerythritol hexaacrylate.

[0054] Preferably, the photoinitiator is one or more of anthraquinones, benzophenones, benzoyls, acridines, oxime esters, and hexaaryldiimidazoles.

[0055] Preferably, the additives include one or more of the following: leveling agents, defoamers, dyes, adhesion additives, color changers, fluorescent agents, polymerization inhibitors, antioxidants, plasticizers, and dispersants.

[0056] Fifthly, the present invention provides an application of a photosensitive dry film resist in printed circuit boards, lead frames, or semiconductor packaging substrates.

[0057] Example 1 The structural formula of the alkali-soluble resin A1 in this embodiment is: Where: a, b, c and d represent the mass percentage of the corresponding polymeric monomers, where a=20%, b=50%, c=20% and d=10%.

[0058] The specific synthetic route is as follows: The specific preparation method includes the following steps: S1: Mix 20g methacrylic acid, 50g methyl methacrylate, 20g styrene, 5.48g maleic anhydride, 0.5g AIBN, and 80g butanone to obtain solution A; mix 0.5g AIBN with 22g butanone to obtain solution B; add 20g butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, react for 4 hours, then add solution B dropwise to the reaction solution for 30 minutes; after the addition is complete, heat to 80℃ and continue reacting for 4 hours to obtain a reaction solution containing primary alkali-soluble resin A; S2: Under ice bath conditions of 0℃, 50.00g of butanone solution containing 5.64g of 2,2,2-trifluoroethylamine was added dropwise to the reaction solution containing primary base soluble resin A obtained in step S1. After the addition was completed, the temperature was raised to room temperature and the reaction was carried out for 18h to obtain a reaction solution containing intermediate base soluble resin B. S3: Add 7.33g of sodium acetate and 164.16g of acetic anhydride to the reaction solution containing intermediate alkali-soluble resin B in step S2, and heat to 100℃ for 18h; after the reaction is complete, separate and purify to obtain alkali-soluble resin A1.

[0059] The alkali-soluble resin A1 prepared in this embodiment has a weight-average molecular weight of 61,500 g / mol and a molecular weight distribution of 1.68.

[0060] Fourier transform infrared spectroscopy was performed on the primary alkali-soluble resin A and alkali-soluble resin A1 prepared in this embodiment, and the results are shown below. Figure 1 It can be seen that in the curve of primary alkali-soluble resin A, 3277cm... -1 The broad peak at 1857 cm⁻¹ is the stretching vibration peak of OH on polymethyl methacrylate. -1 and 1785cm -1 The peak at 1732 cm⁻¹ represents the stretching vibration peak of C=O on polymaleic anhydride.-1 The peak at 1273-1148 cm⁻¹ represents the stretching vibration peak of C=O on polymethacrylic acid and polymethyl methacrylate. -1 The peak at 759 cm⁻¹ represents the stretching vibration peak of CO on polymethacrylic acid and polymethyl methacrylate, and the stretching vibration peak of COC on polymaleic anhydride and polymethyl methacrylate. -1 and 706cm -1 The peak at 1857 cm⁻¹ corresponds to the CH bending vibration peak on polystyrene, indicating the successful preparation of primary alkali-soluble resin A; in the curve of alkali-soluble resin A1, the original peak at 1857 cm⁻¹... -1 and 1785cm -1 The C=O stretching vibration peak on polymaleic anhydride disappears, while the C=O stretching vibration peak on polymaleimide shifts to 1724 cm⁻¹. -1 At this location, it merges with the C=O stretching vibration peaks on polymethacrylic acid and polymethyl methacrylate, 1400~1100 cm⁻¹. -1 The presence of multiple CF stretching vibration peaks at the point indicates that the alkali-soluble resin A1 was successfully prepared.

[0061] Example 2 In this embodiment, the structural formula of alkali-soluble resin A2 is: Where: a, b, c and d represent the mass percentage content of the corresponding polymeric monomers, where a=20%, b=55%, c=20% and d=5%.

[0062] The synthesis route is basically the same as in Example 1; the specific steps are as follows: S1: Mix 20g methacrylic acid, 55g methyl methacrylate, 20g styrene, 2.74g maleic anhydride, 0.5g AIBN, and 80g butanone to obtain solution A; mix 0.5g AIBN with 22g butanone to obtain solution B; add 20g butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, react for 4 hours, then add solution B dropwise to the reaction solution for 30 minutes; after the dropwise addition is complete, heat to 80℃ and continue reacting for 4 hours to obtain a reaction solution containing primary alkali-soluble resin A; S2: Under ice bath conditions of 0℃, 50.00g of butanone solution containing 2.82g of 2,2,2-trifluoroethylamine was added dropwise to the reaction solution of primary base soluble resin A. After the addition was completed, the temperature was raised to room temperature and the reaction was carried out for 18h to obtain a reaction solution containing intermediate base soluble resin B. S3: Add 3.66g sodium acetate and 82.08g acetic anhydride to the reaction solution of intermediate alkali-soluble resin B, heat to 100℃ and react for 18h; after the reaction is complete, separate and purify to obtain alkali-soluble resin A2.

[0063] The alkali-soluble resin A2 prepared in this embodiment has a weight-average molecular weight of 67200 g / mol and a molecular weight distribution of 1.65.

[0064] Example 3 The structural formula of the alkali-soluble resin A3 in this embodiment is: Where: a, b, c and d represent the mass percentage of the corresponding polymeric monomers, where a=20%, b=45%, c=20% and d=15%.

[0065] The synthesis route is basically the same as in Example 1; the specific steps are as follows: S1: Mix 20g methacrylic acid, 45g methyl methacrylate, 20g styrene, 8.21g maleic anhydride, 0.5g AIBN, and 80g butanone to obtain solution A; mix 0.5g AIBN with 22g butanone to obtain solution B; add 20g butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, react for 4 hours, then add solution B dropwise to the reaction solution for 30 minutes; after the addition is complete, heat to 80℃ and continue reacting for 4 hours to obtain a reaction solution containing primary alkali-soluble resin A; S2: Under ice bath conditions of 0℃, 50.00g of butanone solution containing 8.46g of 2,2,2-trifluoroethylamine was added dropwise to the reaction solution of primary base soluble resin A. After the addition was completed, the temperature was raised to room temperature and the reaction was carried out for 18h to obtain a reaction solution containing intermediate base soluble resin B. S3: Add 10.99g sodium acetate and 246.25g acetic anhydride to the reaction solution of intermediate alkali-soluble resin B, and heat to 100℃ for 18h; after the reaction is complete, separate and purify to obtain alkali-soluble resin A3.

[0066] The alkali-soluble resin A3 prepared in this embodiment has a weight-average molecular weight of 58400 g / mol and a molecular weight distribution of 1.81.

[0067] Example 4 The structural formula of the alkali-soluble resin A4 in this embodiment is: Where: a, b, c and d represent the mass percentage of the corresponding polymeric monomers, where a=20%, b=50%, c=20% and d=10%.

[0068] The specific synthetic route is as follows: Includes the following steps: S1: Under ice bath conditions of 0℃, a solution of 100g of butanone containing 25.76g of 2,2,2-trifluoroethylamine was added dropwise to a solution of 100g of butanone containing 25g of maleic anhydride. After the addition was complete, the temperature was raised to room temperature and reacted for 12h. After the reaction was complete, the mixture was separated and purified to obtain intermediate 1. 25g of intermediate 1, 16.65g of sodium acetate and 372.91g of acetic anhydride were mixed and the mixture was heated to 100℃ and reacted for 12h. After separation and purification, monomer 5 was obtained. S2: Mix 20g methacrylic acid, 50g methyl methacrylate, 20g styrene, 10g monomer 5, 0.5g AIBN, and 80g butanone to obtain solution A; mix 0.5g AIBN with 22g butanone to obtain solution B; add 20g butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, continue the reaction for 4 hours; add solution B dropwise to the reaction solution for 30 minutes, and after the addition is complete, heat to 80℃ and continue the reaction for 4 hours. After the reaction is complete, alkali-soluble resin A4 is obtained.

[0069] The alkali-soluble resin A4 prepared in this embodiment has a weight-average molecular weight of 75300 g / mol and a molecular weight distribution of 2.02.

[0070] The monomer 5 prepared in this embodiment was subjected to proton nuclear magnetic resonance spectroscopy, and the results are shown below. Figure 2 . 1 H NMR (400MHz, CDCl3) δ 6.85 (s, 2H), 4.14 (q, J = 8 Hz, 2H).

[0071] The monomer 5 prepared in this embodiment was subjected to carbon NMR spectroscopy, and the results are shown below. Figure 3 . 13 C NMR (100MHz, CDCl3) δ 168.83, 134.56, 122.98 (q, 1 J FC = 278 Hz), 38.66 (q, 2 J FC = 37 Hz).

[0072] Fourier transform infrared spectroscopy was performed on monomer 5 and alkali-soluble resin A4 prepared in this embodiment, and the results are shown below. Figure 4 It can be seen that in the curve of monomer 5, the 3500~3000cm... -1 The peak of the stretching vibration of CH is located at 1719 cm⁻¹. -1The peak of the stretching vibration at C=O is 1612 cm⁻¹. -1 and 1584cm -1 The peak value for C=C stretching vibration is located at 1500~1100cm. -1 The peaks at 3279 cm⁻¹ represent the stretching vibrations of -CF₃ and CN, respectively. Combined with the 1H and 1C NMR spectra of monomer 5, this indicates that monomer 5 was successfully prepared. In the curve of alkali-soluble resin A4, the peak at 3279 cm⁻¹... -1 The broad peak at 3100-2800 cm⁻¹ represents the stretching vibration peak of the OH group on polymethyl methacrylate. -1 The stretching vibration peak at CH is enhanced and broadened, reaching 1725 cm⁻¹. -1 The stretching vibration peak at C=O is enhanced and broadened, from 1500 to 1100 cm⁻¹. -1 The enhanced and broadened peak at 760 cm⁻¹ is attributed to the stretching vibrations of CO on newly added polymethacrylic acid and polymethyl methacrylate, as well as the stretching vibrations of the aromatic ring on polystyrene. -1 and 705cm -1 The peak at this point represents the CH bending vibration peak on polystyrene, confirming the successful preparation of alkali-soluble resin A4.

[0073] Example 5 In this embodiment, the structural formula of alkali-soluble resin A5 is: Where: a, b, c and d represent the mass percentage content of the corresponding polymeric monomers, where a=18%, b=45%, c=25% and d=12%.

[0074] The specific synthetic route is as follows: The specific preparation method includes the following steps: S1: Mix 18g of 3-butenoic acid, 45g of ethyl acrylate, 25g of styrene, 6.57g of maleic anhydride, 0.5g of AIBN, and 80g of butanone to obtain solution A; mix 0.5g of AIBN with 22g of butanone to obtain solution B; add 20g of butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, react for 4 hours, then add solution B dropwise to the reaction solution for 30 minutes; after the addition is complete, heat to 80℃ and continue reacting for 4 hours to obtain a reaction solution containing primary alkali-soluble resin A; S2: Under ice bath conditions of 0℃, 50.00g of butanone solution containing 6.77g of 2,2,2-trifluoroethylamine was added dropwise to the reaction solution containing primary base soluble resin A obtained in step S1. After the addition was completed, the temperature was raised to room temperature and the reaction was carried out for 18h to obtain a reaction solution containing intermediate base soluble resin B. S3: Add 8.79g of sodium acetate and 197.00g of acetic anhydride to the reaction solution containing intermediate alkali-soluble resin B in step S2, and heat to 100℃ for 18h; after the reaction is complete, separate and purify to obtain alkali-soluble resin A5.

[0075] The alkali-soluble resin A5 prepared in this embodiment has a weight-average molecular weight of 60900 g / mol and a molecular weight distribution of 1.88.

[0076] Example 6 The structural formula of the alkali-soluble resin A6 in this embodiment is: Where a, b, c, and d represent the mass percentage content of the corresponding monomers, with a = 25%, b = 52%, c = 15%, and d = 8%. The specific synthetic route is as follows: The specific preparation method includes the following steps: S1: Mix 25g acrylic acid, 52g butyl methacrylate, 15g styrene, 4.64g citrate anhydride, 0.5g AIBN, and 80g butanone to obtain solution A; mix 0.5g AIBN with 22g butanone to obtain solution B; add 20g butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, react for 4 hours, then add solution B dropwise to the reaction solution for 30 minutes; after the addition is complete, heat to 80℃ and continue reacting for 4 hours to obtain a reaction solution containing primary alkali-soluble resin A; S2: Under ice bath conditions of 0℃, 50.00g of butanone solution containing 4.19g of 2,2,2-trifluoroethylamine was added dropwise to the reaction solution containing primary base soluble resin A obtained in step S1. After the addition was completed, the temperature was raised to room temperature and the reaction was carried out for 18h to obtain a reaction solution containing intermediate base soluble resin B. S3: Add 5.44g of sodium acetate and 121.79g of acetic anhydride to the reaction solution containing intermediate alkali-soluble resin B in step S2, and heat to 100℃ for 18h; after the reaction is complete, separate and purify to obtain alkali-soluble resin A6.

[0077] The alkali-soluble resin A6 prepared in this embodiment has a weight-average molecular weight of 68,100 g / mol and a molecular weight distribution of 1.63.

[0078] Example 7 The structural formula of the alkali-soluble resin A7 in this embodiment is: Where: a, b, c and d represent the mass percentage content of the corresponding polymeric monomers, where a=15%, b=48%, c=24% and d=13%.

[0079] The specific synthetic route is as follows: The specific preparation method includes the following steps: S1: Mix 18g 5-hexenoic acid, 45g isooctyl methacrylate, 25g styrene, 5.56g maleic anhydride, 0.5g AIBN, and 80g butanone to obtain solution A; mix 0.5g AIBN with 22g butanone to obtain solution B; add 20g butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, react for 4 hours, then add solution B dropwise to the reaction solution for 30 minutes; after the addition is complete, heat to 80℃ and continue reacting for 4 hours to obtain a reaction solution containing primary alkali-soluble resin A; S2: Under ice bath conditions of 0℃, 50.00g of butanone solution containing 8.63g of 2,2,3,3,3-pentafluoropropylamine was added dropwise to the reaction solution containing primary base soluble resin A obtained in step S1. After the addition was completed, the temperature was raised to room temperature and the reaction was carried out for 18h to obtain a reaction solution containing intermediate base soluble resin B. S3: Add 7.45g sodium acetate and 166.83g acetic anhydride to the reaction solution containing intermediate alkali-soluble resin B in step S2, and heat to 100℃ for 18h; after the reaction is complete, separate and purify to obtain alkali-soluble resin A7.

[0080] The alkali-soluble resin A7 prepared in this embodiment has a weight-average molecular weight of 53700 g / mol and a molecular weight distribution of 1.85.

[0081] Example 8 The structural formula of the alkali-soluble resin A8 in this embodiment is: Where: a, b, c and d represent the mass percentage content of the corresponding polymeric monomers, where a=23%, b=47%, c=15% and d=15%.

[0082] The specific synthetic route is as follows: The specific preparation method includes the following steps: S1: Mix 23g methacrylic acid, 47g benzyl methacrylate, 15g styrene, 5.27g maleic anhydride, 0.5g AIBN, and 80g butanone to obtain solution A; mix 0.5g AIBN with 22g butanone to obtain solution B; add 20g butanone to the reactor and heat to 70℃, then continuously pass solution A into the reactor for 2 hours; after solution A has been completely passed through, react for 4 hours, then add solution B dropwise to the reaction solution for 30 minutes; after the addition is complete, heat to 80℃ and continue reacting for 4 hours to obtain a reaction solution containing primary alkali-soluble resin A; S2: Under ice bath conditions of 0℃, 50.00g of butanone solution containing 10.91g of 2,2,3,3,4,4,4-heptafluorobutylamine was added dropwise to the reaction solution containing primary base soluble resin A obtained in step S1. After the addition was completed, the temperature was raised to room temperature and the reaction was carried out for 18h to obtain a reaction solution containing intermediate base soluble resin B. S3: Add 7.05g sodium acetate and 158.01g acetic anhydride to the reaction solution containing intermediate alkali-soluble resin B in step S2, and heat to 100℃ for 18h; after the reaction is complete, separate and purify to obtain alkali-soluble resin A8.

[0083] The alkali-soluble resin A8 prepared in this embodiment has a weight-average molecular weight of 69,800 g / mol and a molecular weight distribution of 1.69.

[0084] Comparative Example 1 The chemical formula of the alkali-soluble resin A9 prepared in this comparative example is as follows: Where: a1, a2, b, c and d represent the mass percentage content of the corresponding polymeric monomers, where a1=16.76%, a2=7.82%, b=50%, c=20%, and d=5.42%.

[0085] The synthesis route is as follows: Includes the following steps: 16.76g of methacrylic acid, 7.82g of 2-(trifluoromethyl)acrylic acid, 50g of methyl methacrylate, 20g of styrene, 5.42g of maleimide, 0.5g of AIBN, and 80g of butanone were mixed to obtain solution A; 0.5g of AIBN was mixed with 22g of butanone to obtain solution B; 20g of butanone was added to a reactor and the temperature was raised to 70℃, then solution A was continuously passed into the reactor for 2 hours; after solution A was completely passed through, the reaction was allowed to proceed for 4 hours, and then solution B was added dropwise to the reaction solution for 30 minutes. After the addition was complete, the temperature was raised to 80℃ and the reaction was continued for 4 hours to obtain alkali-soluble resin A9.

[0086] The alkali-soluble resin A9 prepared in this comparative example has a weight-average molecular weight of 60300 g / mol and a molecular weight distribution of 1.78.

[0087] Comparative Example 2 The chemical formula of the alkali-soluble resin A10 prepared in this comparative example is as follows: Where: a, b, c and d represent the mass percentage content of the corresponding polymeric monomers, where a=20%, b1=45.19%, b2=9.39%, c=20%, and d=5.42%.

[0088] The synthesis route is as follows: Includes the following steps: 20g of methacrylic acid, 45.19g of methyl methacrylate, 9.39g of trifluoroethyl methacrylate, 20g of styrene, 5.42g of maleimide, 0.5g of AIBN, and 80g of butanone were mixed to obtain solution A; 0.5g of AIBN was mixed with 22g of butanone to obtain solution B; 20g of butanone was added to a reactor and the temperature was raised to 70℃, then solution A was continuously passed into the reactor for 2 hours; after solution A was completely passed through, the reaction was allowed to proceed for 4 hours, and then solution B was added dropwise to the reaction solution for 30 minutes. After the addition was complete, the temperature was raised to 80℃ and the reaction was continued for 4 hours to obtain alkali-soluble resin A10.

[0089] The weight-average molecular weight of the alkali-soluble resin A10 prepared in this comparative example is 62100 g / mol, and the molecular weight distribution is 1.76.

[0090] Comparative Example 3 The chemical formula of the alkali-soluble resin A11 prepared in this comparative example is as follows: Where: a, b, c and d represent the mass percentage content of the corresponding polymeric monomers, where a=20%, b=50%, c1=14.96%, c2=9.62%, and d=5.42%.

[0091] The synthesis route is as follows: Includes the following steps: 20g methacrylic acid, 50g methyl methacrylate, 14.96g styrene, 9.62g p-trifluoromethylstyrene, 5.42g maleimide, 0.5g AIBN, and 80g butanone were mixed to obtain solution A; 0.5g AIBN was mixed with 22g butanone to obtain solution B; 20g butanone was added to a reactor and the temperature was raised to 70℃, then solution A was continuously passed into the reactor for 2 hours; after solution A was completely passed through, the reaction was allowed to proceed for 4 hours, and then solution B was added dropwise to the reaction solution for 30 minutes. After the addition was complete, the temperature was raised to 80℃ and the reaction was continued for 4 hours to obtain alkali-soluble resin A11.

[0092] The weight-average molecular weight of the alkali-soluble resin A11 prepared in this comparative example is 59400 g / mol, and the molecular weight distribution is 1.82.

[0093] Examples 9-16 and Comparative Examples 4-6 The compositions of the photosensitive dry film resists of Examples 9-16 and Comparative Examples 4-6 are shown in Table 1.

[0094] Table 1 Photopolymerizable monomer B is composed of the following components: 5 parts of methoxy polyethylene glycol (350) monoacrylate, 20 parts of 10 (ethoxy) bisphenol A dimethacrylate, 5 parts of 6 (propoxy) bisphenol A dimethacrylate, 10 parts of 3 (ethoxy) trimethylolpropane triacrylate, and 4 parts of di(trimethylolpropane) tetraacrylate.

[0095] The photoinitiator C is 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-diimidazole (BCIM).

[0096] Additive D is composed of the following components: 0.5 parts of leuco crystal violet, 0.05 parts of malachite green, 0.8 parts of p-toluenesulfonamide, and 0.03 parts of 2,6-di-tert-butyl-4-methylphenol.

[0097] Alkali-soluble resin A: A1 is the alkali-soluble resin of Example 1. A2 is the alkali-soluble resin from Example 2. A3 is the alkali-soluble resin of Example 3. A4 is the alkali-soluble resin of Example 4. A5 is the alkali-soluble resin of Example 5. A6 is the alkali-soluble resin of Example 6. A7 is the alkali-soluble resin of Example 7. A8 is the alkali-soluble resin of Example 8. A9 is the alkali-soluble resin of Comparative Example 1. A10 is the alkali-soluble resin of Comparative Example 2. A11 is the alkali-soluble resin of Comparative Example 3. The solvent consists of the following components: 8 parts acetone, 10 parts toluene, and 5 parts methanol.

[0098] The following describes the sample preparation methods (including the preparation of photosensitive dry films, film application, exposure, and development) of Examples 9-16 and Comparative Examples 4-6, as well as the sample evaluation methods and evaluation results.

[0099] (1) Sample preparation method Preparation of photosensitive dry film The materials from Examples 1-8 and Comparative Examples 1-3 listed in Table 1 were mixed uniformly to prepare photosensitive resin compositions. Subsequently, these compositions were coated onto the surface of a 15 μm thick PET support film using a coating machine (model: AB4220, manufactured by TQC, Netherlands). After baking at 80°C for 10 minutes, a photosensitive layer with a thickness of 38 μm was obtained. Finally, a PE film was coated onto the surface of the photosensitive layer for protection, completing the preparation of the photosensitive dry film.

[0100] [Screen protector] After surface treatments such as polishing, micro-etching, washing, and drying, the copper substrate with a 35μm thick rolled 1.2mm thick copper foil laminated on it was preheated to 80℃. The laminating machine roller temperature was set to 110℃, the air pressure to 0.35MPa, and the lamination speed to 1.5m / min. After removing the PE protective film from the surface of the photosensitive dry film obtained in the above examples and comparative examples, the above photosensitive resin composition was laminated onto the copper substrate to obtain the laminated test substrate.

[0101]

exposure

[0102]

development

[0103] (2) Evaluation Methods [Evaluation of ISO sensitivity] On the above-mentioned film-coated test substrate, a Stouffer 41-level stepped exposure scale was placed for photosensitivity testing. After the exposure process, the test substrate was left to stand for more than 20 minutes, then the PET film layer was peeled off, and a 1.0 wt% sodium carbonate aqueous solution was sprayed at 30°C to remove the unexposed resist layer. The development time was 2.0 times the minimum development time. After the above operation, a cured film obtained by curing the photosensitive resin composition was formed on the substrate surface. The exposure energy (mJ / cm) when the number of residual segments of the stepped exposure scale obtained by the cured film was 20 segments. 2 The photosensitivity of the photosensitive resin composition was evaluated, with a smaller value indicating better photosensitivity.

[0104] Basis for judgment: ○: 70-90mJ / cm 2 ; △: 90-110mJ / cm 2 ; ×:>110mJ / cm 2 .

[0105] [Resolution Evaluation] On the aforementioned test substrate after coating, photomask data with a linewidth / spacing width of n:n (unit: μm) was used to expose the substrate at an energy level that ensured a residual stage number of 20 after development using a Stouffer 41-stage exposure ruler. After the development process, the resist pattern was observed using an optical microscope. The minimum linewidth at which a complete cured resist line was formed was used as the adhesion value to evaluate adhesion (μm). The smaller this value, the better the resolution.

[0106] [Evaluation of Adhesion] On the aforementioned test substrate after coating, using photomask data with a wiring pattern of n:400 (unit: μm) linewidth / spacing width, exposure was performed at an energy level that ensured a residual stage number of 20 after development using a Stouffer 41-stage exposure ruler. After the development process, the resist pattern was observed using an optical microscope, and the minimum linewidth at which a complete cured resist line was formed was used as the adhesion value to evaluate adhesion (μm). The smaller this value, the better the adhesion.

[0107] [Electroplating Resistance Evaluation] On the aforementioned test substrate after film application, exposure was performed using photomask data with a wiring pattern having a linewidth / spacing width of 1 / 1 to 6 / 6 (unit: mil) to achieve an energy level of 20 for the residual stage number after development using a Stouffer 41-stage exposure ruler. After the development process, copper plating pretreatment was performed in the following sequence: immersion in 10% degreasing solution for 10 min (40°C) → water rinsing for 1 min → micro-etching with 4% sodium thiosulfate solution for 1 min → acid rinsing with 10% dilute sulfuric acid for 1 min. Then, the substrate was immersed in the copper plating solution at room temperature and 3.0 A / dm². 2 Copper plating was performed for 30 minutes. Afterwards, a pre-tin plating treatment was performed, consisting of a 1-minute water rinse followed by a 1-minute pickling with 10% methanesulfonic acid. Then, the sample was immersed in the tin plating solution at 22°C and 2.0 A / dm³. 2 Tin plating was performed for 20 minutes. Afterwards, the sample was rinsed with water, then stripped with a 3.0% sodium hydroxide solution (55°C), rinsed again, and dried. Additionally, after the resist was removed, the sample was observed from above using an optical microscope to check for copper plating penetration. Sections were prepared, and the presence of plating penetration was confirmed using a SU1000 scanning electron microscope (manufactured by Hitachi).

[0108] Basis for judgment: ○: No plating penetration; △: Slight plating penetration; ×: Severe plating penetration.

[0109] [Evaluation of the Pollution Caused by Electroplating] The exposed dry film resist sample (with 20 remaining segments on the staged exposure scale) was taken at 0.8m. 2 The solution was dissolved in copper sulfate electroplating solution at a ratio of / L, soaked at room temperature for 24 hours, and then the dry film resist was filtered off to obtain the sample to be tested. The total organic carbon (TOC) content of the electroplating solution sample was measured using the high-temperature catalytic combustion oxidation method, with the electroplating solution sample without resist used as a blank sample. The higher the measured TOC value, the greater the pollution of the electroplating solution.

[0110] Basis for judgment: ○: After excluding blanks, the TOC value is <500ppm; △: After excluding blanks, 500ppm≤TOC value≤1000ppm; ×: After removing the blank, the TOC value is >1000ppm.

[0111] [Side profile evaluation] In the resist pattern used for the above resolution evaluation, the part with the best resolution was sliced ​​and observed using a SU1000 scanning electron microscope (manufactured by Hitachi).

[0112] Basis for judgment: ○: The cross-section of the dry film head is rectangular; △: Some sections of the dry film head have an inverted trapezoidal shape; ×: The cross-section of the dry film head is severely inverted trapezoidal or the bottom is hollowed out, or there are obvious cracks on the sidewalls.

[0113] Evaluation results The test results for evaluation items 1-4 of Examples 9-16 and Comparative Examples 4-6 are shown in Table 2.

[0114] Table 2 As can be seen from the data in Table 2, the photosensitive dry film resist prepared in Example 9 has good photosensitivity, resolution, adhesion, and electroplating resistance. The photosensitive resin combination prepared in Comparative Example 4 has relatively poor resolution, adhesion, and electroplating resistance, indicating that fluorinated groups are not suitable for grafting onto acrylic monomers. The photosensitive dry film resist prepared in Comparative Example 5 has insufficient adhesion and electroplating resistance, indicating that fluorinated groups are not suitable for grafting onto acrylate monomers. The photosensitive dry film resist prepared in Comparative Example 6 has insufficient resolution, adhesion, and electroplating resistance, indicating that fluorinated groups are not suitable for styrene monomers. In Examples 10 and 11, the excessive or insufficient content of polymaleimide in the alkali-soluble resin of the photosensitive dry film resist has a certain impact on electroplating resistance. The alkali-soluble resin used in Example 12 was prepared using a different method, and its electroplating resistance was significantly lower than that in Example 9. This may be because a fluorinated maleimide was prepared first, leading to alternating polymerization of styrene and the fluorinated maleimide during subsequent polymerization, which affected the electroplating resistance of the alkali-soluble resin. The alkali-soluble resins used in the photosensitive dry film resists in Examples 13-16 differed in type, but all exhibited good overall performance.

[0115] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An alkali-soluble resin characterized by comprising: The structural formula is shown as Formula I: In the formula, R1 is a hydrogen atom or a methyl group; R2 is a C0-C6 methylene group; R3 is a hydrogen or a methyl group; R4 is one of a C1-C10 straight-chain alkyl group, a branched-chain alkyl group, and an aromatic group; R5 is a C1-C10 alkyl group or an aromatic group substituted by single fluorine or multiple fluorine; R6 is a hydrogen or a methyl group; a, b, c, and d represent the mass percentage of the corresponding polymerized monomer, 15%≤a≤25%; 45%≤b≤55%; 15%≤c≤25%; 5%≤d≤15%, and a+b+c+d=100%.

2. The alkali-soluble resin according to claim 1, wherein the weight average molecular weight of the alkali-soluble resin is 40,000-100,000 g / mol, and the molecular weight distribution is 1.2-4.

0. And / or: the R5 is a C1-C10 alkyl group substituted by multiple fluorine. The synthetic route is as follows:

3. A method for producing an alkali-soluble resin, characterized by, The method comprises the following steps: (1) mixing monomer 1, monomer 2, monomer 3, monomer 4, a first part of an initiator, and a solvent to obtain solution A; mixing a second part of the initiator and a solvent to obtain solution B; adding a solvent into a reactor and heating to a reaction temperature, then continuously feeding solution A into the reactor, after the feeding is completed, setting a reaction time, then adding solution B dropwise into the reaction solution, after the dropwise addition is completed, heating to continue the reaction, to obtain a reaction solution containing a primary alkali-soluble resin A; (2) under ice bath conditions, adding a solution containing NH2-R5 into the reaction solution containing the primary alkali-soluble resin A, after the dropwise addition is completed, heating to room temperature to react, to obtain a reaction solution containing an intermediate alkali-soluble resin B; (3) adding sodium acetate and acetic anhydride into the reaction solution containing the intermediate alkali-soluble resin B, heating to a set temperature to react, after the reaction is completed, performing separation and purification, to obtain the alkali-soluble resin.

4. The method for preparing the alkali-soluble resin according to claim 3, wherein in step (1), the monomer 1 is one or more of acrylic acid, methacrylic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 3-methylbut-3-enoic acid, and 4-methyl-4-pentenoic acid; And / or: the monomer 2 is one or more of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, tert-butyl acrylate, butyl methacrylate, tert-butyl methacrylate, n-octyl acrylate, isooctyl acrylate, n-octyl methacrylate, isooctyl methacrylate, benzyl acrylate, and benzyl methacrylate; And / or: the monomer 4 is one or both of maleic anhydride and citraconic anhydride; And / or: the mass ratio of the monomer 1, the monomer 2, and the monomer 3 is (15-25):(45-55):(15-25); The molar ratio of the monomer 4 to NH2-R5 in step (2) is 1:(1-1.05); the mass ratio of the monomer 3 to the total mass of the monomer 4 and NH2-R5 is (15-25):(5.5-16.9). ​ ​ And / or: the first part of the initiator is 0.1-2% of the total mass of monomer 1, monomer 2, monomer 3 and monomer 4; the second part of the initiator is 0.1-2% of the total mass of monomer 1, monomer 2, monomer 3 and monomer 4; And / or: the first part of the initiator and the second part of the initiator are each independently one or more of azobisisobutyronitrile, azobisisoheptyl nitrile, dibenzoyl peroxide, tert-butyl peroxybenzoate, di-tert-butyl peroxide; And / or: In step (2), NH2-R5 is one or more of 4-fluoroaniline, 3-fluoroaniline, 2,2-difluoroethylamine, 2,2,2-trifluoroethylamine, 2,2,3,3,3-pentafluoropropylamine, 2,2,3,3,4,4,4-heptafluorobutylamine, 1H,1H-perfluoroheptylamine, p-trifluoromethylaniline, m-trifluoromethylaniline, 3-fluoro-4-trifluoromethylaniline; And / or: In step (3), the amount of sodium acetate added is 1-14% of the mass of the intermediate base-soluble resin B in step (2); the amount of acetic anhydride added is 0.5-5 times the mass of the intermediate base-soluble resin B in step (2).

5. The method for preparing a base-soluble resin according to claim 3 or 4, characterized in that, In step (1), the reaction temperature is 60-80°C; the set time is 3-5 h; and the temperature is raised to 70-90°C for continued reaction for 4-6 h; And / or: In step (2), the reaction time is 12-24 h; And / or: In step (3), the set temperature is 80-120°C; and the reaction time is 12-24 h.

6. A method for producing an alkali-soluble resin, characterized by, The synthesis route is as follows: Comprising the following steps: (1) Under ice bath conditions, a solution containing monomer 4 is added dropwise to a solution containing NH2-R5, after the dropwise addition is complete, the temperature is raised to room temperature for the first stage reaction, after the reaction is complete, the intermediate 1 is obtained after separation and purification; intermediate 1, sodium acetate and acetic anhydride are mixed, the temperature is raised to the set temperature for the second stage reaction, and monomer 5 is obtained after separation and purification; (2) Monomer 1, monomer 2, monomer 3, monomer 5, the first part of the initiator and the solvent are mixed to obtain solution A; the second part of the initiator and the solvent are mixed to obtain solution B; the solvent is added to the reactor and the temperature is raised to the reaction temperature, then solution A is continuously fed into the reactor, after solution A is completely fed, the reaction is set for a certain time, then solution B is added dropwise to the reaction solution, after the dropwise addition is complete, the temperature is raised to the set temperature for continued reaction, after the reaction is complete, the base-soluble resin is obtained after separation and purification.

7. The method for preparing a base-soluble resin according to claim 6, characterized in that, In step (1), the molar ratio of monomer 4 to NH2-R5 is 1:(1.00-1.05); the amount of sodium acetate added is 50-80% of the mass of intermediate 1; and the amount of acetic anhydride added is 10-20 times the mass of intermediate 1; And / or: In step (2), the monomer 1, monomer 2, monomer 3 and monomer 5 are in a mass ratio of (15-25):(45-55):(15-25):(5-15); the first part of the initiator is 0.1-2% of the total mass of monomer 1, monomer 2, monomer 3 and monomer 5; the second part of the initiator is 0.1-2% of the total mass of monomer 1, monomer 2, monomer 3 and monomer 5.

8. A photosensitive dry film resist, characterized by, The alkali-soluble resin according to any one of claims 1-2; or the alkali-soluble resin prepared by the preparation method according to any one of claims 3-7.

9. The photosensitive dry film resist according to claim 8, wherein the polymeric binder is a copolymer of styrene and maleic anhydride. According to the mass fraction ratio, it comprises: alkali-soluble resin 42-65 parts, photopolymerizable monomer 21-48 parts, photoinitiator 0.1-5 parts, auxiliary agent 0.1-5 parts.

10. Use of the photosensitive dry film resist according to claim 8 or 9 in a printed circuit board, a lead frame or a semiconductor package substrate.

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