A resin composition for a package substrate and a solder resist dry film prepared therefrom

Abstract

This invention discloses the raw materials, preparation method, and application method of a solder resist dry film made from a resin composition for encapsulating a carrier board. The raw materials include: modified acrylic resin, acrylate monomer, thermosetting resin, photopolymerization initiator, inorganic filler, additives, and solvent. The process includes the following steps: S1: mixing the modified acrylic resin, acrylate monomer, and solvent; S2: mixing the thermosetting resin and flame retardant; S3: adding the photopolymerization initiator and defoamer and mixing; S4: adding the inorganic filler, leveling agent, and film-forming aid; S5: coating the above resin composition using a coating machine and drying at 60-120°C for 10-30 minutes to obtain the solder resist dry film. The prepared solder resist dry film has advantages such as high transmittance, high workability, good coefficient of thermal expansion, and high resolution.

Description

Technical Field

[0001] This invention relates to the field of B32B27 / 06, and more particularly to a resin composition for encapsulating substrates and the solder resist dry film prepared therefrom. Background Technology

[0002] Existing solder resist dry films are mainly used in rigid circuit boards, carrier-like boards, and some low-end carrier boards. They do not have high requirements for crack resistance and electrical insulation performance, but they are difficult to match with high-requirement IC carrier boards.

[0003] Chinese patent CN201520177317 discloses a novel photosensitive solder resist dry film, comprising a PET film. The PET film is disposed on the outer surface of the solder resist dry film body and serves as the first layer structure. A photosensitive solder resist coating layer is disposed on the inner side of the PET film. A composite protective film is wrapped around the outer surface of the photosensitive solder resist coating layer and serves as the third layer. However, the solder resist film is thick.

[0004] Chinese patent CN201710098304 discloses a positive photosensitive water-soluble solder resist dry film and its uses. The solder resist dry film has good resolution, adhesion, flexibility and high temperature resistance, and can be used for the production of high-density PCB boards, but it cannot meet the requirements of high-requirement IC carrier boards.

[0005] Chinese patent CN201210111602 discloses a photosensitive water-based solder resist composition and a photosensitive water-based solder resist dry film, providing a photosensitive water-based solder resist composition with high adhesion and a photosensitive water-based solder resist dry film made from the photosensitive water-based solder resist composition, but its crack resistance is not good enough. Summary of the Invention

[0006] To address the aforementioned problems, this invention discloses a solder resist dry film of a resin composition for encapsulating a carrier board, the raw materials of which include: modified acrylic resin, acrylate monomer, thermosetting resin, photopolymerization initiator, inorganic filler, additives, and solvent.

[0007] Preferably, by weight, the raw materials include: 20-50 parts modified acrylic resin, 15-35 parts acrylate monomer, 15-25 parts thermosetting resin, 5-15 parts photopolymerization initiator, 1-10 parts inorganic filler, 2.8-8 parts additives, and 8-16 parts solvent.

[0008] More preferably, by weight, the raw materials include: 38 parts modified acrylic resin, 22 parts acrylate monomer, 20 parts thermosetting resin, 11 parts photopolymerization initiator, 5 parts inorganic filler, 6 parts additives, and 12 parts solvent.

[0009] In one embodiment, the additives include: leveling agents, film-forming aids, flame retardants, and defoamers.

[0010] Preferably, by weight, the additives include: 1-3 parts leveling agent, 0.5-2 parts film-forming agent, 1-2 parts flame retardant, and 0.3-1 parts defoamer.

[0011] More preferably, by weight, the additives include: 2 parts leveling agent, 1.5 parts film-forming agent, 1.5 parts flame retardant, and 1 part defoamer.

[0012] Preferably, the modified acrylic resin is selected from anhydride-modified epoxy acrylic resin.

[0013] More preferably, the anhydride-modified epoxy acrylate resin, brand name Lotader 5500, is purchased from Arkema Ltd., France.

[0014] Preferably, the acid value of the anhydride-modified epoxy acrylate resin is 80-220 mg KOH / g.

[0015] More preferably, the acid value of the anhydride-modified epoxy acrylate resin is 120 mg KOH / g.

[0016] Preferably, the anhydride-modified epoxy acrylate resin has a weight-average molecular weight of 4,500 to 60,000.

[0017] More preferably, the anhydride-modified epoxy acrylate resin has a weight-average molecular weight of 45,000.

[0018] Preferably, the acrylate monomer is selected from one or two of trifunctional or tetrafunctional acrylate monomers.

[0019] More preferably, the acrylate monomer is selected from trifunctional acrylate monomers.

[0020] More preferably, the trifunctional acrylate monomer is an acrylate monomer containing a carbon-carbon double bond.

[0021] More preferably, the trifunctional acrylate monomer is 3(propoxy)propanetriol triacrylate, grade 1025-15-6 4HBA, purchased from Shanghai Yongzheng Chemical Co., Ltd.

[0022] Preferably, the thermosetting resin is selected from one or more of amino-curing resins, epoxy-curing resins, and polyurethane-based curing resins.

[0023] More preferably, the weight ratio of amino-curing resin, epoxy-curing resin and polyurethane-curing resin in the thermosetting resin is 1:(1-3):3.

[0024] More preferably, the weight ratio of amino-curing resin, epoxy-curing resin, and polyurethane-curing resin in the thermosetting resin is 1:1.2:3.

[0025] The applicant discovered that when the weight ratio of amino-curing resin, epoxy-curing resin, and polyurethane-curing resin in the thermosetting resin used is 1:1.2:3, the resulting solder resist dry film exhibits excellent flexibility and good crack resistance. The applicant believes that this may be because the anhydride in the anhydride-modified acrylic resin reacts with the amino group of the amino-curing resin to form a long-chain compound. In the subsequent photoinitiation reaction, a longer molecular chain is formed, while the other acrylate monomers polymerize normally to obtain shorter molecular chains. In this way, the long and short molecular chains intertwine and crisscross within the solder resist dry film, resulting in excellent crack resistance.

[0026] Preferably, the polyurethane curing resin, grade E-300, is purchased from Beipiao Nako Fine Chemicals Co., Ltd.

[0027] Preferably, the epoxy curing resin, grade CFSP, is purchased from Carbon Technology Group Co., Ltd.

[0028] Preferably, the amino-cured resin, grade CYMEL 325, is purchased from Foshan Weng Kai'er Trading Co., Ltd.

[0029] Preferably, the photoinitiator is selected from benzoin derivatives, acetophenone derivatives, benzophenone derivatives, anthraquinone derivatives, α-aminoacetophenone derivatives, acylphosphine oxide derivatives, and oxime esters.

[0030] More preferably, the photoinitiator is selected from α-aminoacetophenone photoinitiators.

[0031] More preferably, the photoinitiator is 4-bis(diethylamino)benzophenone, CAS number 90-93-7.

[0032] Preferably, the inorganic filler is selected from one or more of modified silica, modified calcium silicate, and modified alumina.

[0033] Further preferably, the inorganic filler is modified silica with an average particle size of 8-10 μm.

[0034] More preferably, the modified silica has an average particle size of 9 μm.

[0035] The preferred modified silica grade is PST-R02, which was purchased from Nanjing Baoket New Materials Co., Ltd.

[0036] The applicant has discovered that the addition of modified inorganic fillers can not only enhance the resolution of solder resist dry films but also improve their high-temperature resistance. The applicant believes this is likely due to the smaller particle size and higher transparency of the inorganic fillers. Furthermore, the mixing of the modified inorganic fillers with the components of the solder resist dry film allows the dry film, which originally had poor high-temperature performance, to acquire high-temperature resistance due to the high-temperature properties of the modified inorganic fillers.

[0037] Preferably, the leveling agent is selected from one or two of silicone-based and acrylic-based agents.

[0038] More preferably, the leveling agent is selected from silicone leveling agents, and the brand name is BYK346, which is purchased from Shanghai Kaiyin Chemical Co., Ltd.

[0039] Preferably, the film-forming aid is selected from one or more of alcohols, alcohol esters, alcohol ethers, and alcohol ether esters.

[0040] More preferably, the film-forming aid is selected from alcohol ester film-forming aids, CAS: 25265-77-4, purchased from Shandong Baien New Materials Co., Ltd.

[0041] The applicant discovered that the coefficient of thermal expansion of the solder resist dry film prepared after adding the film-forming aid decreased. The reason may be that the film-forming aid has the effect of reducing the surface tension of the mixture. When the prepared solder resist dry film needs to expand when heated, the low surface tension of the solder resist dry film can effectively deform the solder resist dry film when heated, reducing the internal stress, thereby giving the solder resist dry film a better coefficient of thermal expansion.

[0042] Preferably, the flame retardant is selected from one or two of organic flame retardants and inorganic flame retardants.

[0043] More preferably, the flame retardant is selected from inorganic flame retardants, and the brand name DC8008 is purchased from Guangzhou Yinuo Chemical Technology Co., Ltd.

[0044] Preferably, the defoamer is selected from one or more of non-silicone, polyether, and organosilicon types.

[0045] More preferably, the defoamer is selected from silicone defoamers, brand name JN-2085, purchased from Shandong Juneng Chemical Co., Ltd.

[0046] The applicant discovered that the resolution of the solder resist dry film increased after the addition of defoamer. The possible reason is that during the preparation of the solder resist dry film, the air carried by the mixture during stirring is expelled. Since there is no gas scattering light in the solder resist dry film, the solder resist dry film has a higher transmittance.

[0047] Preferably, the solvent is selected from one or more of ketone solvents, aromatic solvents, petroleum solvents, alcohol ether solvents, and amide solvents.

[0048] More preferably, the solvent is selected from aromatic solvents, and the brand name S-1500 is purchased from Nanjing Kunna Chemical Co., Ltd.

[0049] This invention also discloses a method for preparing a solder resist dry film of a resin composition for encapsulating a substrate, comprising the following steps:

[0050] S1: Mix the modified acrylic resin, acrylate monomer, and solvent.

[0051] S2: Mix the thermosetting resin and flame retardant.

[0052] S3: Add photopolymerization initiator and defoamer and mix.

[0053] S4: Add inorganic fillers, leveling agents, and film-forming aids.

[0054] S5: The above resin composition can be dried at a temperature of 60-120°C for 10-30 minutes using a coating machine to obtain a solder resist dry film.

[0055] In one embodiment, the mixing speed in steps S1, S2, S3, S4, and S5 is maintained at 800-100 rpm.

[0056] Preferably, the rotational speed is 950 rpm.

[0057] In one embodiment, the mixing time in steps S1, S2, S3, S4, and S5 is 10-30 minutes.

[0058] Preferably, the mixing time is 20 minutes.

[0059] Preferably, in step S5, the above resin composition is dried at 90°C for 25 minutes using a coating machine to obtain a solder resist dry film.

[0060] The present invention also discloses a method for applying the solder resist dry film: the solder resist dry film is pressed together using a vacuum laminator, and after exposure, development and post-curing, a circuit board using the solder resist dry film as a solder resist is prepared, with the film thickness being 15-20μm.

[0061] Preferably, the film thickness is 18 μm.

[0062] In one embodiment, the temperature of the vacuum film is 60-70°C, the vacuum time is 15-30s, the pressing time is 15-30s, and the pressing pressure is 0.4-0.6kg / cm2.

[0063] Preferably, the vacuum pressing temperature is 65°C, the vacuum time is 25s, the pressing time is 25s, and the pressing pressure is 0.5kg / cm2.

[0064] Beneficial effects:

[0065] This invention enables the solder resist dry film to have excellent crack resistance by using a mixture of various thermosetting resins.

[0066] The present invention improves the resolution of solder resist dry film by adding modified inorganic fillers, which have good dispersibility and small particle size.

[0067] This invention reduces the surface tension of the solder resist dry film by using film-forming aids, thereby reducing the internal stress of the solder resist dry film and giving it a good coefficient of thermal expansion.

[0068] This invention reduces the bubble content of the mixture during the production process by adding defoamer, thereby reducing light scattering and resulting in a higher transmittance of the solder resist dry film.

[0069] This invention achieves uniform mixing of all components in the solder resist dry film by adding additives in stages, resulting in a solder resist dry film with high workability. Specific Implementation

[0070] Example 1

[0071] Example 1 of the present invention discloses a solder resist dry film of a resin composition for encapsulating a carrier board. By weight, the raw materials include: 38 parts of anhydride modified acrylic resin, 22 parts of acrylate monomer, 20 parts of thermosetting resin, 11 parts of photopolymerization initiator, 5 parts of modified inorganic filler, 6 parts of additives, and 12 parts of solvent.

[0072] The additives include, by weight, 2 parts leveling agent, 1.5 parts film-forming agent, 1.5 parts flame retardant, and 1 part defoamer.

[0073] The weight ratio of amino-curing resin, epoxy-curing resin, and polyurethane-curing resin in the thermosetting resin is 1:1:3.

[0074] The acid value of the anhydride-modified epoxy acrylate resin is 80 mg KOH / g.

[0075] The anhydride-modified epoxy acrylate resin has a weight-average molecular weight of 4500.

[0076] The anhydride-modified epoxy acrylate resin, brand name Lotader 5500, was purchased from Arkema Ltd., France.

[0077] The acrylate monomer is 3(propoxy)propanetriol triacrylate, grade 1025-15-6 4HBA, purchased from Shanghai Yongzheng Chemical Co., Ltd.

[0078] The polyurethane curing resin, grade E-300, was purchased from Beipiao Nako Fine Chemicals Co., Ltd.

[0079] The epoxy curing resin, grade CFSP, was purchased from Carbon Technology Group Co., Ltd.

[0080] The amino-cured resin, brand name CYMEL 325, was purchased from Foshan Weng Kai'er Trading Co., Ltd.

[0081] The photoinitiator is selected from α-aminoacetophenone photoinitiators, with CAS number 90-93-7.

[0082] The inorganic filler is a modified inorganic filler with an average particle size of 8 μm, brand name PST-R02, and purchased from Nanjing Baoket New Materials Co., Ltd.

[0083] The leveling agent is selected from silicone leveling agents, brand name BYK346, and purchased from Shanghai Kaiyin Chemical Co., Ltd.

[0084] The film-forming aid is selected from alcohol ester film-forming aids, CAS: 25265-77-4, and purchased from Shandong Baien New Materials Co., Ltd.

[0085] The flame retardant is selected from inorganic flame retardants, and the brand name DC8008 was purchased from Guangzhou Yinuo Chemical Technology Co., Ltd.

[0086] The defoamer is selected from silicone defoamers, brand name JN-2085, and purchased from Shandong Juneng Chemical Co., Ltd.

[0087] The solvent is selected from aromatic solvents, and the brand name S-1500 was purchased from Nanjing Kunna Chemical Co., Ltd.

[0088] This embodiment also discloses a method for preparing a solder resist dry film of a resin composition for encapsulating a carrier board, comprising the following steps:

[0089] S1: Mix the modified acrylic resin, acrylate monomer, and solvent.

[0090] S2: Mix the thermosetting resin and flame retardant.

[0091] S3: Add photopolymerization initiator and defoamer and mix.

[0092] S4: Add inorganic fillers, leveling agents, and film-forming aids.

[0093] S5: The above resin composition can be dried at 60°C for 10 minutes using a coating machine to obtain a solder resist dry film.

[0094] The mixing time for steps S1, S2, S3, S4, and S5 is 10 minutes, and the mixing speed is 800 rpm.

[0095] This embodiment also discloses the application method of the solder resist dry film: the solder resist dry film is pressed using a vacuum laminator, and after exposure, development and post-curing, a circuit board using the solder resist dry film as solder resist is prepared, with a film thickness of 15μm.

[0096] The vacuum pressing temperature is 60℃, the vacuum time is 15s, the pressing time is 15s, and the pressing pressure is 0.4kg / cm2.

[0097] Example 2

[0098] Example 2 of the present invention discloses a solder resist dry film of a resin composition for encapsulating a carrier board. By weight, the raw materials include: 38 parts of anhydride modified acrylic resin, 22 parts of acrylate monomer, 20 parts of thermosetting resin, 11 parts of photopolymerization initiator, 5 parts of modified inorganic filler, 6 parts of additives, and 12 parts of solvent.

[0099] The additives include, by weight, 2 parts leveling agent, 1.5 parts film-forming agent, 1.5 parts flame retardant, and 1 part defoamer.

[0100] The weight ratio of amino-curing resin, epoxy-curing resin, and polyurethane-curing resin in the thermosetting resin is 1:1.2:3.

[0101] The acid value of the anhydride-modified epoxy acrylate resin is 120 mg KOH / g.

[0102] The anhydride-modified epoxy acrylate resin has a weight-average molecular weight of 45,000.

[0103] The anhydride-modified epoxy acrylate resin, brand name Lotader 5500, was purchased from Arkema Ltd., France.

[0104] The acrylate monomer is 3(propoxy)propanetriol triacrylate, grade 1025-15-6 4HBA, purchased from Shanghai Yongzheng Chemical Co., Ltd.

[0105] The polyurethane curing resin, grade E-300, was purchased from Beipiao Nako Fine Chemicals Co., Ltd.

[0106] The epoxy curing resin, grade CFSP, was purchased from Carbon Technology Group Co., Ltd.

[0107] The amino-cured resin, brand name CYMEL 325, was purchased from Foshan Weng Kai'er Trading Co., Ltd.

[0108] The photoinitiator is selected from α-aminoacetophenone photoinitiators, with CAS number 90-93-7.

[0109] The inorganic filler is a modified inorganic filler with an average particle size of 9 μm, brand name PST-R02, and was purchased from Nanjing Baoket New Materials Co., Ltd.

[0110] The leveling agent is selected from silicone leveling agents, brand name BYK346, and purchased from Shanghai Kaiyin Chemical Co., Ltd.

[0111] The film-forming aid is selected from alcohol ester film-forming aids, CAS: 25265-77-4, and purchased from Shandong Baien New Materials Co., Ltd.

[0112] The flame retardant is selected from inorganic flame retardants, and the brand name DC8008 was purchased from Guangzhou Yinuo Chemical Technology Co., Ltd.

[0113] The defoamer is selected from silicone defoamers, brand name JN-2085, and purchased from Shandong Juneng Chemical Co., Ltd.

[0114] The solvent is selected from aromatic solvents, and the brand name S-1500 was purchased from Nanjing Kunna Chemical Co., Ltd.

[0115] This embodiment also discloses a method for preparing a solder resist dry film of a resin composition for encapsulating a carrier board, comprising the following steps:

[0116] S1: Mix the modified acrylic resin, acrylate monomer, and solvent.

[0117] S2: Mix the thermosetting resin and flame retardant.

[0118] S3: Add photopolymerization initiator and defoamer and mix.

[0119] S4: Add inorganic fillers, leveling agents, and film-forming aids.

[0120] S5: The above resin composition can be dried at 90°C for 25 minutes using a coating machine to obtain a solder resist dry film.

[0121] The mixing time for steps S1, S2, S3, S4, and S5 is 20 minutes, and the mixing speed is 950 rpm.

[0122] This embodiment also discloses the application method of the solder resist dry film: the solder resist dry film is pressed using a vacuum laminator, and after exposure, development and post-curing, a circuit board using the solder resist dry film as solder resist is prepared, with a film thickness of 18μm.

[0123] The vacuum pressing temperature is 65℃, the vacuum time is 25s, the pressing time is 25s, and the pressing pressure is 0.5kg / cm2.

[0124] Example 3

[0125] Example 3 of the present invention discloses a solder resist dry film of a resin composition for encapsulating a carrier board. By weight, the raw materials include: 50 parts of anhydride modified acrylic resin, 35 parts of acrylate monomer, 25 parts of thermosetting resin, 15 parts of photopolymerization initiator, 10 parts of modified inorganic filler, 8 parts of additives, and 16 parts of solvent.

[0126] The additives include, by weight, 2 parts leveling agent, 2 parts film-forming agent, 2 parts flame retardant, and 1 part defoamer.

[0127] The weight ratio of amino-curing resin, epoxy-curing resin, and polyurethane-curing resin in the thermosetting resin is 1:3:3.

[0128] The acid value of the anhydride-modified epoxy acrylate resin is 220 mg KOH / g.

[0129] The anhydride-modified epoxy acrylate resin has a weight-average molecular weight of 60,000.

[0130] The anhydride-modified epoxy acrylate resin, brand name Lotader 5500, was purchased from Arkema Ltd., France.

[0131] The acrylate monomer is 3(propoxy)propanetriol triacrylate, grade 1025-15-6 4HBA, purchased from Shanghai Yongzheng Chemical Co., Ltd.

[0132] The polyurethane curing resin, grade E-300, was purchased from Beipiao Nako Fine Chemicals Co., Ltd.

[0133] The epoxy curing resin, grade CFSP, was purchased from Carbon Technology Group Co., Ltd.

[0134] The amino-cured resin, brand name CYMEL 325, was purchased from Foshan Weng Kai'er Trading Co., Ltd.

[0135] The photoinitiator is selected from α-aminoacetophenone photoinitiators, with CAS number 90-93-7.

[0136] The inorganic filler is a modified inorganic filler with an average particle size of 10 μm, brand name PST-R02, and purchased from Nanjing Baoket New Materials Co., Ltd.

[0137] The leveling agent is selected from silicone leveling agents, brand name BYK346, and purchased from Shanghai Kaiyin Chemical Co., Ltd.

[0138] The film-forming aid is selected from alcohol ester film-forming aids, CAS: 25265-77-4, and purchased from Shandong Baien New Materials Co., Ltd.

[0139] The flame retardant is selected from inorganic flame retardants, and the brand name DC8008 was purchased from Guangzhou Yinuo Chemical Technology Co., Ltd.

[0140] The defoamer is selected from silicone defoamers, brand name JN-2085, and purchased from Shandong Juneng Chemical Co., Ltd.

[0141] The solvent is selected from aromatic solvents, and the brand name S-1500 was purchased from Nanjing Kunna Chemical Co., Ltd.

[0142] This embodiment also discloses a method for preparing a solder resist dry film of a resin composition for encapsulating a carrier board, comprising the following steps:

[0143] S1: Mix the modified acrylic resin, acrylate monomer, and solvent.

[0144] S2: Mix the thermosetting resin and flame retardant.

[0145] S3: Add photopolymerization initiator and defoamer and mix.

[0146] S4: Add inorganic fillers, leveling agents, and film-forming aids.

[0147] S5: The above resin composition can be dried at 120°C for 30 minutes using a coating machine to obtain a solder resist dry film.

[0148] The mixing time for steps S1, S2, S3, S4, and S5 is 30 minutes, and the mixing speed is 1000 rpm.

[0149] This embodiment also discloses the application method of the solder resist dry film: the solder resist dry film is pressed using a vacuum laminator, and after exposure, development and post-curing, a circuit board using the solder resist dry film as solder resist is prepared, and the film thickness is 20μm.

[0150] The vacuum pressing temperature is 70℃, the vacuum time is 30s, the pressing time is 30s, and the pressing pressure is 0.6kg / cm2.

[0151] Comparative Example 1

[0152] The difference from Example 2 is that the particle size of the inorganic modified filler is 50 μm.

[0153] Comparative Example 2

[0154] The difference from Example 2 is that no defoamer is added.

[0155] Comparative Example 3

[0156] The difference from Example 2 is that no film-forming aid is added.

[0157] Comparative Example 4

[0158] The difference from Example 2 is that the weight ratio of amino-curing resin, epoxy-curing resin and polyurethane-curing resin in the thermosetting resin is 1:1.2:5.

[0159] Performance testing

[0160] 1. Resolution Test

[0161] As a negative mask for resolution evaluation, a negative pattern with 60µm via openings is used to confirm the cross-sectional shape at the solder resist opening. Judgment criteria: 1. Positive conical structure; 2. Inverted conical structure; 3. Undercut structure.

[0162] 2. Chemical nickel-palladium resistance

[0163] Commercially available electroless nickel plating solution and electroless gold plating solution were used for plating under conditions of 0.5 μm nickel and 0.03 μm gold. The presence or absence of solder resist penetration was evaluated, followed by evaluation of solder resist peeling by tape removal. Judgment criteria: 1. No penetration or peeling observed; 2. Minor penetration confirmed after plating, but no peeling observed after tape removal; 3. Peeling observed after tape removal.

[0164] 3. Crack resistance

[0165] Refer to ISO 1421-2016 Determination of tensile strength and elongation at break of coated rubber or plastic fabrics.

[0166] 4. PCT Test

[0167] The nickel-palladium-gold coated substrate was placed in a high-temperature, high-pressure, and high-humidity bath at 121°C, 2 atmospheres, and 100% humidity for 50 hours. Evaluation criteria: 1. No obvious expansion or discoloration; 2. No obvious peeling (partial peeling or discoloration); 3. Obvious expansion and discoloration.

[0168] The test results are all recorded in Table 1.

[0169] Table 1

[0170]

Claims

1. A solder resist dry film of a resin composition for encapsulating a carrier board, characterized in that, By weight, the raw materials include: 20-50 parts modified acrylic resin, 15-35 parts acrylate monomer, 15-25 parts thermosetting resin, 5-15 parts photopolymerization initiator, 1-10 parts inorganic filler, 2.8-8 parts additives, and 8-16 parts solvent. The thermosetting resin is selected from amino-curing resin, epoxy-curing resin and polyurethane-curing resin, and the weight ratio of amino-curing resin, epoxy-curing resin and polyurethane-curing resin in the thermosetting resin is 1:(1-3):

3. The inorganic filler is modified silica with an average particle size of 8-10 μm; The modified acrylic resin is an anhydride-modified epoxy acrylic resin, and the acid value of the anhydride-modified epoxy acrylic resin is 80-220 mg KOH / g. The additives include: leveling agents, film-forming agents, flame retardants, and defoamers; The film-forming aid is selected from alcohol ester film-forming aids.

2. The solder resist dry film according to claim 1, characterized in that, The acrylate monomer is selected from one or two of trifunctional and tetrafunctional acrylate monomers.

3. The solder resist dry film according to claim 1, characterized in that, The photopolymerization initiator is selected from one or more of the following: benzoin, acetophenone, benzophenone, anthraquinone, α-aminoacetophenone, acylphosphine oxide, and oxime ester.

4. A method for preparing the solder resist dry film according to claim 1, characterized in that, Includes the following steps: S1: Mix the modified acrylic resin, acrylate monomer, and solvent; S2: Mix thermosetting resin and flame retardant S3: Add photopolymerization initiator and defoamer and mix; S4: Add inorganic fillers, leveling agents, and film-forming aids; S5: After coating the above resin composition with a coating machine, the solder resist dry film can be obtained by drying at a temperature of 60-120°C for 10-30 minutes.

5. A method for applying the solder resist dry film according to any one of claims 1-3: the solder resist dry film is pressed together using a vacuum laminator, and after exposure, development and post-curing, a circuit board using the solder resist dry film as a solder resist is prepared, the film thickness being 15-20 μm.

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