Photosensitive resin composition, photosensitive dry film, cured film, circuit board and display module

Abstract

The invention provides a photosensitive resin composition, a photosensitive dry film, a cured film, a printed circuit board and a display module. The photosensitive resin composition is prepared from the following components in parts by weight: 100 to 115 parts of alkali-soluble resin, 5 to 20 parts of photopolymerization monomer, 3 to 10 parts of sulfydryl-terminated ester-containing compound, 1 to 5 parts of photoinitiator and 10 to 30 parts of epoxy resin, wherein the epoxy resin comprises sulfur-containing epoxy resin. By controlling the types and contents of the components of the photosensitive resin composition in the range, even if the curing time is short in the photocuring and thermocuring processes, the surface layer and the deep layer of a cured film can be uniformly cured, and meanwhile, the photosensitive resin composition also has high sensitivity, heat resistance and good developing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of photosensitive resin compositions, and in particular to a photosensitive resin composition, a photosensitive dry film, a cured film, a printed circuit board, and a display module. Background Art

[0002] In electronic products, it is usually necessary to cover the printed circuit board (PCB) with a solder mask as a permanent protective film, which is not only used to prevent circuit corrosion and disconnection and short circuits between wires caused by multiple welding points, but also to inhibit corrosion of the circuit substrate. The solder mask material is generally formed by a photosensitive resin composition after exposure and development to form a solder mask pattern, which is then heated and cured. In order to play a permanent protective role and meet the subsequent PCB process treatment, the solder mask material needs to have excellent heat resistance, hardness, scratch resistance, acid and alkali resistance, solvent resistance, resistance to cold and hot shocks, and anti-warping properties, and also needs to have good exposure performance and alkali development ability.

[0003] In order to ensure the appearance of the solder mask, it is often necessary to add pigments and toners to change the color of the solder mask. However, some PCB products require a matte effect, which will affect the exposure performance of the solder mask, especially the black matte solder mask. The solder mask generally requires a higher exposure energy, and the increase in exposure energy will also increase the time of the exposure process, thereby seriously reducing the production efficiency of the solder mask. In addition, due to the incomplete deep curing of the photosensitive resin composition, it will not only cause serious side erosion and reduce the adhesion and window opening performance after development, but also cause problems such as infiltration plating, solder mask blistering, warping and shedding in the subsequent process, which seriously affects the performance of the PCB.

[0004] At present, the sensitivity is increased by increasing the content of photoinitiator in the photosensitive resin composition system. Although the exposure energy can be significantly reduced, the photoinitiator, as a small molecule compound, will precipitate in the subsequent PCB nickel-gold process, causing contamination of the nickel-gold solution, which requires frequent replacement of the solution, resulting in increased costs. At the same time, excessive photoinitiators in the photosensitive resin composition will also lead to reduced performance of the solder mask after photothermal curing. For the problem of incomplete deep curing during the photocuring process, which leads to side etching in the window area of ​​the final solder mask, the refractive index can be increased by using nano-inorganic fillers with high refractive index or modifying the photosensitive resin to achieve consistency of surface and deep curing. However, the inorganic nano-fillers with high refractive index are currently expensive and have poor dispersion in the resin and are easy to agglomerate. Modifying the photosensitive resin not only increases the process flow, but also increases costs. Summary of the invention

[0005] The main purpose of the present invention is to provide a photosensitive resin composition, a photosensitive dry film, a cured film, a circuit board, and a display module to solve the problems of low sensitivity, long exposure time, uneven curing of the surface and deep layers, and long thermal curing time of the photosensitive resin composition in the prior art.

[0006] In order to achieve the above-mentioned object, according to one aspect of the present invention, a photosensitive resin composition is provided, which comprises, in parts by weight: 100 to 115 parts of an alkali-soluble resin, 5 to 20 parts of a photopolymerizable monomer, 3 to 10 parts of a terminal mercapto ester compound, 1 to 5 parts of a photoinitiator and 10 to 30 parts of an epoxy resin; wherein the epoxy resin comprises a sulfur-containing epoxy resin.

[0007] Furthermore, the mass ratio of the terminal mercapto ester compound to the photopolymerizable monomer is 0.1-0.5:1; preferably, the weight portion of the terminal mercapto ester compound is 4-7 parts, and / or the weight portion of the epoxy resin is 15-25 parts.

[0008] Furthermore, the epoxy resin also includes a sulfur-free epoxy resin: wherein, based on the sum of the mass contents of the episulfide groups and the epoxy groups in the epoxy resin being 100%, the mass ratio of the episulfide groups to the epoxy groups is 15-70:30-85, preferably 15-40:60-85.

[0009] Further, the photopolymerizable monomer is a multifunctional acrylate, preferably, the photopolymerizable monomer is selected from any one or more of a difunctional monomer, a trifunctional monomer, a tetrafunctional monomer, a pentafunctional monomer and a hexafunctional monomer; preferably, the difunctional monomer is selected from tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, (10) ethoxylated bisphenol A diacrylate, (10) propoxylated bisphenol A diacrylate, (10) ethoxylated propoxylated bisphenol A diacrylate, (4) ethoxylated bisphenol A diacrylate any one or more of ester, (4) propoxylated bisphenol A diacrylate, ethoxylated propoxylated bisphenol A diacrylate and tricyclodecane dimethanol diacrylate; preferably, the trifunctional monomer is selected from trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, (3) ethoxylated trimethylolpropane triacrylate, (3) propoxylated trimethylolpropane triacrylate, (3) ethoxylated propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate ester, (3) propoxylated trimethylolpropane triacrylate, ethoxylated propoxylated trimethylolpropane triacrylate, (6) ethoxylated trimethylolpropane triacrylate, (6) propoxylated trimethylolpropane triacrylate and (6) ethoxylated propoxylated trimethylolpropane triacrylate; preferably, the tetrafunctional monomer is selected from any one or more of pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate and ethoxylated propoxylated pentaerythritol tetraacrylate. ; The preferred pentafunctional monomer is dipentaerythritol pentaacrylate; the preferred hexafunctional monomer is dipentaerythritol hexaacrylate; and / or, the ratio of the total mass of the difunctional monomer and the trifunctional monomer to the total mass of the tetrafunctional monomer and the hexafunctional monomer in the photopolymerizable monomer is 0.3-0.7:1.2-3; and / or, the mass ratio of the difunctional monomer and the trifunctional monomer is 0.1-0.3:0.5-1, and / or, the mass ratio of the tetrafunctional monomer and the hexafunctional monomer is 0.3-0.5:0.6-1.

[0010] Further, the terminal mercapto ester compound is an ester compound containing a terminal mercapto group, and preferably the terminal mercapto ester compound is selected from any one or more of isooctyl thioglycolate, pentaerythritol tetrakis-3-mercaptopropionate, ethylene glycol dithioacetate, glycerol thioglycolate, ethyl thioglycolate, butyl thioglycolate, isopropyl thioglycolate, methyl 3-mercaptopropionate, butyl 3-mercaptopropionate and trimethylolpropane tris(3-mercaptopropionate); and / or the alkali-soluble resin is a carboxyl-containing epoxy acrylic resin; preferably the alkali-soluble resin is an epoxy acrylic resin containing a carboxyl group. The soluble resin is selected from any one or more of acid-modified bisphenol A epoxy acrylic resin, acid-modified bisphenol F epoxy acrylic resin, acid-modified alicyclic epoxy acrylic resin and acid-modified phenolic epoxy acrylic resin; and / or the photoinitiator is a free radical photoinitiator and / or a cationic photoinitiator; preferably, the free radical photoinitiator is selected from 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, 2,4,6-trimethylbenzoyl phenyl phosphonic acid ethyl ester, 2-methyl-1-(4-methylthiophenyl)-2-morpholine 1-Hydroxy-1-propanone, 2-isopropylthioxanthone, 1-hydroxycyclohexylphenyl ketone, benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, tetramethylthirone, tetraethylthirone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2,4-diethylthioxanthone, benzoin dimethyl ether, 2-hydroxy-methylphenylpropane-1-one, ethyl 4-(N,N-dimethylamino)benzoate and 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl] ]-1-acetone, any one or more thereof; and / or, the cationic photoinitiator is selected from any one or more of triphenylsulfonium hexafluorophosphate, 4-phenylthiophenyl diphenylsulfonium salt, 4-dodecyloxyphenyl diphenylsulfonium hexafluoroantimonate, bis[(4-diphenylsulfonium)benzene] sulfide-bis-hexafluorophosphate, 4-phenylthiophenyl diphenylsulfonium salt, (4-hydroxyphenyl)methyl (benzyl) hexasulfonium fluorophosphate, 4-acetoxyphenyl dimethylsulfonium hexafluoroantimonate and diphenyliodonium hexafluorophosphate.

[0011] Furthermore, the preparation method of the sulfur-containing epoxy resin comprises: reacting a raw material including a non-sulfur epoxy resin, a sulfur-containing compound and a first solvent to obtain a sulfur-containing epoxy resin; wherein the sulfur-containing compound is potassium thiocyanate and / or thiourea; and / or the non-sulfur epoxy resin is a multifunctional resin, preferably the non-sulfur epoxy resin is selected from bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, phenolic epoxy resin, aliphatic glycidyl ether resin Any one or more of epoxy resin, brominated epoxy resin, glycidyl phthalate, glycidyl amine epoxy resin, alicyclic epoxy resin, epoxidized olefin, hydantoin epoxy resin and imide epoxy resin; and / or the first solvent is water and / or ethanol solution; and / or the mass ratio of the sulfur-free epoxy resin to the sulfur-containing compound is 150-200:50-80; and / or the reaction temperature is 50-70°C; and / or the reaction time is 300-600min.

[0012] According to another aspect of the present invention, a photosensitive dry film is provided, which is obtained by coating and drying a photosensitive resin composition in sequence, and the photosensitive resin composition is the above-mentioned photosensitive resin composition.

[0013] According to another aspect of the present invention, there is provided a cured film, which is obtained by coating, drying and curing a composition in sequence, or by curing a photosensitive dry film, wherein the composition is the above-mentioned photosensitive resin composition, and the photosensitive dry film is the above-mentioned photosensitive dry film, wherein the curing includes light curing, heat curing or light and heat dual curing.

[0014] According to another aspect of the present invention, a circuit board is provided, comprising a curing film, wherein the curing film is the curing film described above.

[0015] According to another aspect of the present invention, a display module is provided, including a curing film, wherein the curing film is the above curing film.

[0016] By applying the technical scheme of the present invention, the photosensitive resin composition of the present application uses an alkali-soluble resin as a base, and adding a photopolymerizable monomer and a photoinitiator can make the photosensitive resin composition undergo a polymerization reaction under light; the terminal mercapto ester compound can be used as a monomer component to react with an olefinic unsaturated bond, thereby improving the photosensitivity of the photosensitive resin composition, and at the same time can also reduce the energy required for the photosensitive resin composition in the photocuring process, thereby significantly reducing the exposure time of the photocuring process; the sulfur-containing epoxy resin is used as a heat-curing component in the photosensitive resin composition, and the thiol (-SH) or sulfur anion (S) generated after the ring-opening of the episulfide group in the sulfur-containing epoxy resin under heating conditions -) can promote the ring opening of epoxy groups, thereby promoting the curing reaction between epoxy resin, curing agent and alkali-soluble resin, and thus improving the cross-linked network structure density, modulus and glass transition temperature of the photosensitive resin composition after curing. By controlling the type and content of each component of the photosensitive resin composition of the present application within the above range, even if the curing time is short in the photocuring and thermal curing process, the surface layer and deep layer of the cured film can be uniformly cured, and at the same time, it also has high sensitivity, heat resistance and good developing performance. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0018] As analyzed in the background technology of this application, the photosensitive resin composition in the prior art has problems such as low sensitivity, long exposure time, uneven surface and deep layer curing, and long thermal curing time. In order to solve the above problems, this application provides a photosensitive resin composition, a photosensitive dry film, a cured film, a circuit board, and a display module.

[0019] In a typical embodiment of the present application, a photosensitive resin composition is provided, which includes, in parts by weight: 100 to 115 parts of an alkali-soluble resin, 5 to 20 parts of a photopolymerizable monomer, 3 to 10 parts of a terminal mercapto ester compound, 1 to 5 parts of a photoinitiator and 10 to 30 parts of an epoxy resin; wherein the epoxy resin includes a sulfur-containing epoxy resin.

[0020] The photosensitive resin composition of the present application uses an alkali-soluble resin as a base, and the addition of a photopolymerizable monomer and a photoinitiator can cause the photosensitive resin composition to undergo a polymerization reaction under light; the terminal mercapto ester compound can be used as a monomer component to react with an olefinic unsaturated bond, thereby increasing the sensitivity of the photosensitive resin composition and reducing the energy of the photosensitive resin composition during the photocuring process, thereby significantly reducing the exposure time of the photocuring process; the sulfur-containing epoxy resin is used as a heat-curing component in the photosensitive resin composition, and the thiol (-SH) or sulfur anion (S) generated by the ring-opening of the episulfide group in the sulfur-containing epoxy resin under heating conditions - ) can promote the ring opening of epoxy groups, thereby promoting the curing reaction between epoxy resin, curing agent and alkali-soluble resin, and thus improving the cross-linked network structure density, modulus and glass transition temperature of the photosensitive resin composition after curing. By controlling the type and content of each component of the photosensitive resin composition of the present application within the above range, even if the curing time is short in the photocuring and thermal curing process, the surface layer and deep layer of the cured film can be uniformly cured, and at the same time, it also has high sensitivity, heat resistance and good developing performance.

[0021] In one embodiment of the present application, the mass ratio of the terminal mercapto ester compound to the photopolymerizable monomer is 0.1-0.5:1; in order to further improve the properties of the photosensitive resin composition such as sensitivity and curing uniformity, the weight proportion of the terminal mercapto ester compound is preferably 4-7 parts, and / or the weight proportion of the epoxy resin is 15-25 parts.

[0022] It is preferred to control the mass ratio of terminal thiol ester compounds and photopolymerizable monomers within the above range, which helps the thiol group of the terminal thiol ester compounds to react with the unsaturated double bonds in the photopolymerizable monomers to form a cross-linked network during the photocuring process, and compared with the photopolymerizable monomers, the high reactivity of the thiol group in the terminal thiol ester compounds helps to further improve the sensitivity; at the same time, too high a mass ratio of terminal thiol ester compounds to photopolymerizable monomers is not conducive to developability in alkaline solutions, and too low a mass ratio of terminal thiol ester compounds to photopolymerizable monomers is not conducive to improving the sensitivity of the photosensitive resin composition. Therefore, it is preferred to control the mass ratio of terminal thiol ester compounds to photopolymerizable monomers within the above range, which helps to take into account both the developability and sensitivity of the photosensitive resin composition.

[0023] In one embodiment of the present application, the epoxy resin also includes a sulfur-free epoxy resin: wherein, taking the sum of the mass contents of the episulfide groups and the epoxy groups in the epoxy resin as 100%, the mass ratio of the episulfide groups to the epoxy groups is 15-70:30-85, preferably 15-40:60-85.

[0024] Preferably, the content ratio of the episulfide group to the epoxy group in the epoxy resin is controlled within the above range, which helps to further promote the thermal curing reaction of the photosensitive resin composition, thereby helping to improve the heat resistance and acid and alkali resistance of the cured film obtained after the photosensitive resin composition is cured; too much episulfide group content in the epoxy resin is not only not conducive to the storage of the photosensitive resin composition, but also increases the refractive index of the epoxy resin, resulting in a large difference between the refractive index of the epoxy resin and the filler in the auxiliary agent, thereby causing uneven photocuring of the surface and deep layers of the photosensitive resin composition, thereby increasing the side erosion of the edge of the cured film pattern; too little episulfide group content is not conducive to the thermal curing reaction, thereby reducing the degree of cross-linking reaction, and further reducing the heat resistance, acid and alkali resistance and other properties of the cured film. Therefore, by controlling the content ratio of the episulfide group to the epoxy group in the sulfur-containing epoxy resin within the above range, it is helpful to carry out the thermal curing reaction of the photosensitive resin composition, thereby helping to uniformly cure the surface and deep layers of the cured film and improve the heat resistance and acid and alkali resistance of the cured film.

[0025] In one embodiment of the present application, the photopolymerizable monomer is a multifunctional acrylate. Preferably, the photopolymerizable monomer is selected from any one or more of a difunctional monomer, a trifunctional monomer, a tetrafunctional monomer, a pentafunctional monomer and a hexafunctional monomer; preferably, the difunctional monomer is selected from tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, (10) ethoxylated bisphenol A diacrylate, (10) propoxylated bisphenol A diacrylate, (10) ethoxylated propoxylated bisphenol A diacrylate, (4) ethoxylated bisphenol A diacrylate, (4) propoxylated bisphenol A diacrylate, ethoxylated propoxylated bisphenol A diacrylate and tricyclodecane dimethanol diacrylate; preferably, the trifunctional monomer is selected from trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, (3) ethoxylated trimethylolpropane triacrylate, (3) propoxylated trimethylolpropane triacrylate, (3) ethoxylated propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate. acrylate, (3) propoxylated trimethylolpropane triacrylate, ethoxylated propoxylated trimethylolpropane triacrylate, (6) ethoxylated trimethylolpropane triacrylate, (6) propoxylated trimethylolpropane triacrylate and (6) ethoxylated propoxylated trimethylolpropane triacrylate; preferably, the tetrafunctional monomer is selected from any one or more of pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate and ethoxylated propoxylated pentaerythritol tetraacrylate. species; preferably the pentafunctional monomer is dipentaerythritol pentaacrylate; preferably the hexafunctional monomer is dipentaerythritol hexaacrylate; and / or, the ratio of the total mass of the difunctional monomer and the trifunctional monomer to the total mass of the tetrafunctional monomer and the hexafunctional monomer in the photopolymerizable monomer is 0.3-0.7:1.2-3; and / or, the mass ratio of the difunctional monomer and the trifunctional monomer is 0.1-0.3:0.5-1, and / or, the mass ratio of the tetrafunctional monomer and the hexafunctional monomer is 0.3-0.5:0.6-1.

[0026] It is preferred to control the types of photopolymerizable monomers within the above range, and further control the ratio of the total mass of difunctional monomers and trifunctional monomers to the total mass of tetrafunctional monomers and hexafunctional monomers, the mass ratio of difunctional monomers to trifunctional monomers, and the mass ratio of tetrafunctional monomers to hexafunctional monomers within the above range, which helps to control the viscosity of the photosensitive resin composition, thereby facilitating subsequent coating processing and improving the adhesion with the PCB. At the same time, the tetrafunctional monomers and hexafunctional monomers help the photosensitive resin composition to form a denser cross-linked structure after photothermal curing, thereby improving the heat resistance of the cured film. Among them, the functionality in the photopolymerizable monomer refers to the number of double bonds in the monomer molecule that can participate in the polymerization reaction.

[0027] In order to further improve the synergistic effect between the components of the photosensitive resin composition, in one embodiment of the present application, the terminal mercapto ester compound is an ester compound containing a terminal mercapto group, and the terminal mercapto ester compound is preferably selected from any one or more of isooctyl thioglycolate, pentaerythritol tetrakis-3-mercaptopropionate, ethylene glycol bisthioglycolate, glycerol thioglycolate, ethyl thioglycolate, butyl thioglycolate, isopropyl thioglycolate, methyl 3-mercaptopropionate, butyl 3-mercaptopropionate and trimethylolpropane tris(3-mercaptopropionate); and / or, the alkali-soluble resin is a carboxyl-containing epoxy acrylic resin; preferably, the alkali-soluble resin is selected from any one or more of acid-modified bisphenol A epoxy acrylic resin, acid-modified bisphenol F epoxy acrylic resin, acid-modified alicyclic epoxy acrylic resin and acid-modified phenolic epoxy acrylic resin; and / or, the photoinitiator is a free radical photoinitiator and / or a cationic photoinitiator; preferably, the free radical photoinitiator is selected from 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-methyl -1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, 2-isopropylthioxanthone, 1-hydroxycyclohexylphenyl ketone, benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, tetramethylthrone, tetraethylthrone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2,4-diethylthioxanthone, benzoin dimethyl ether, 2-hydroxy-methylphenylpropane-1-one, ethyl 4-(N,N-dimethylamino)benzoate and 2-hydroxy-2-methyl-1-[4-(2 -hydroxyethoxy)phenyl]-1-propanone, any one or more thereof; and / or, the cationic photoinitiator is selected from any one or more of triphenylsulfonium hexafluorophosphate, 4-phenylthiophenyl diphenylsulfonium salt, 4-dodecyloxyphenyl diphenylsulfonium hexafluoroantimonate, bis[(4-diphenylsulfonium)benzene] sulfide-bis-hexafluorophosphate, 4-phenylthiophenyl diphenylsulfonium salt, (4-hydroxyphenyl)methyl (benzyl) hexasulfonium fluorophosphate, 4-acetoxyphenyl dimethylsulfonium hexafluoroantimonate and diphenyliodonium hexafluorophosphate.

[0028] Preferably, the photosensitive resin composition further comprises 1 to 7 parts by weight of a curing agent, preferably 2 to 5 parts by weight; and 47 to 80 parts by weight of an auxiliary agent, preferably 52 to 72 parts by weight; the curing agent is preferably selected from any one or more of a polyamine curing agent, an imidazole curing agent, an acid anhydride curing agent, a boron amine and its salt curing agent; the curing agent is preferably selected from 2-methylimidazole, 2-ethylimidazole, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl disulfide, 3-aminobenzylamine, m-phenylenediamine, 3-amino-5- Mercapto-1,2,4-triazole, 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, 1,3-bis(2,4,6-trimethylphenyl)imidazole chloride, 1-tritylimidazole, 4-imidazole-1-phenylpropiotone, 1-ethyl-3-methylimidazole tetrafluoroborate, 1-ethylimidazole, 1-allylimidazole, 2,4,5-triphenylimidazole, melamine, melamine phosphate, melamine phosphate, trichloromelamine, hexamethylol melamine, 1,8-diazabicyclo[5,4, 0] any one or more of dodec-7-ene, 4-cyanobenzylamine, 4,4'-diaminodiphenyl sulfone, 1-ethyl-3-methylimidazolium dicyanamide, 1-butyl-3-methylimidazolium dicyanamide, boron trifluoride and boron trifluoride ethylamine complex; preferably, the curing agent is an acid anhydride curing agent, and / or the mass ratio of the acid anhydride curing agent to the sulfur-containing epoxy resin is 2-5:15-25; preferably, the auxiliary agent includes a filler, a functional auxiliary agent and a second solvent; wherein the weight portion of the filler is 15-40 parts, preferably The weight portion of the functional additive is 20 to 35 parts; the weight portion of the functional additive is 2 to 10 parts, preferably 2 to 7 parts; the weight portion of the second solvent is 25 to 35 parts, preferably 30 parts; and / or the filler is an inorganic filler, preferably the inorganic filler is barium sulfate and / or silicon dioxide; and / or the functional additive is selected from any one or more of carbon black, colorant, defoamer, antioxidant and leveling agent; and / or the second solvent is selected from any one or more of γ-butyrolactone, diethylene glycol monoethyl ether acetate, DBE, preferably γ-butyrolactone.

[0029] Preferably, the curing agent is an anhydride curing agent. Generally, the curing temperature required for an anhydride curing agent as a curing agent for epoxy resin is relatively high, and tertiary amines, quaternary ammonium salts, boron amine complexes, metal organic complexes, etc. are required as accelerators. Preferably, the mass ratio of the anhydride curing agent to the sulfur-containing epoxy resin is controlled within the above range. The episulfide group of the sulfur-containing epoxy resin in the photosensitive resin composition is more active and is more likely to open the ring to generate sulfur anions or thiol groups and generate oxygen anions, thereby facilitating an anhydride reaction with the anhydride curing agent to generate disulfide bonds, promoting the generation of carboxylates in the anhydride curing agent, and further promoting the cross-linking reaction between the sulfur-containing epoxy resin and the anhydride curing agent or the alkali-soluble resin. Furthermore, the photosensitive resin composition forms a denser cross-linked network in a faster time.

[0030] The types and weight proportions of the filler, functional additive and second solvent in the additive are preferably within the above ranges, which helps to promote the full mixing of the components of the photosensitive resin composition, thereby improving the synergistic effect of the components.

[0031] In one embodiment of the present application, the preparation method of the sulfur-containing epoxy resin comprises: reacting a raw material including a non-sulfur epoxy resin, a sulfur-containing compound and a first solvent to obtain a sulfur-containing epoxy resin; wherein the sulfur-containing compound is potassium thiocyanate and / or thiourea; and / or, the non-sulfur epoxy resin is a multifunctional resin, preferably the non-sulfur epoxy resin is selected from bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, phenolic epoxy resin, aliphatic shrink Any one or more of glyceryl ether resin, brominated epoxy resin, glycidyl phthalate, glycidyl amine epoxy resin, alicyclic epoxy resin, epoxidized olefin, hydantoin epoxy resin and imide epoxy resin; and / or the first solvent is water and / or ethanol solution; and / or the mass ratio of sulfur-free epoxy resin to sulfur-containing compound is 150-200:50-80; and / or the reaction temperature is 50-70°C; and / or the reaction time is 300-600min.

[0032] The sulfur-containing epoxy resin is synthesized by reacting the above raw materials, and preferably the types of the sulfur-containing compound, the sulfur-free epoxy resin and the first solvent, the mass ratio of the sulfur-free epoxy resin and the sulfur-containing compound, and the temperature and time of the reaction are controlled within the above ranges, which helps the oxygen atoms of the epoxy resin to be replaced by the sulfur atoms of the sulfur-containing compound, thereby generating a sulfur-containing epoxy resin containing both episulfide groups and epoxy groups.

[0033] In another typical embodiment of the present application, a photosensitive dry film is provided, which is obtained by coating and drying a photosensitive resin composition in sequence, wherein the photosensitive resin composition is the above-mentioned photosensitive resin composition. Preferably, the drying temperature is 85 to 100° C.; and / or the drying time is 30 to 50 minutes; and the thickness of the photosensitive dry film is 15 to 50 μm.

[0034] The photosensitive dry film obtained by coating and drying the photosensitive resin composition has high sensitivity and is easy to solidify.

[0035] In another typical embodiment of the present application, a cured film is provided, which is obtained by coating, drying and curing the composition in sequence, or by curing the photosensitive dry film, wherein the composition is the above-mentioned photosensitive resin composition, and the photosensitive dry film is the above-mentioned photosensitive dry film, wherein the curing includes light curing, heat curing or dual light and heat curing.

[0036] The required curing time of the above-mentioned cured film is short, and the surface and deep layers of the cured film can be uniformly cured. Wherein, curing refers to light and heat dual curing. When the cured film is used as a solder mask, some types of solder masks can be only light-cured or only heat-cured. Even a dark solder mask (black) has high sensitivity, heat resistance, good exposure performance and alkali development ability. The thickness of the preferred cured film is within the above range, which helps to meet the current circuit board demand for the cured film and improve the protective effect of the cured film on the circuit board.

[0037] In another typical embodiment of the present application, a circuit board is provided, comprising a cured film, which is the cured film described above.

[0038] The circuit board including the cured film has good corrosion resistance, thereby preventing the circuit from being broken due to corrosion and the problem of short circuits between lines caused by too many welding points.

[0039] In another typical embodiment of the present application, a display module is provided, comprising a curing film, and the curing film is the curing film described above.

[0040] The display module including the cured film has good display performance.

[0041] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0042] Example 1

[0043] Preparation of sulfur-containing epoxy resin: 200g of bisphenol A epoxy resin BNE-186 (Changchun Chemical) was dissolved in 100mL of ethanol solution and added to a four-necked flask by weight; 80g of sulfur-containing compound potassium thiocyanate (KSCN) was dissolved in 80mL of distilled water and 80mL of ethanol solution, mixed evenly and added to a dropping funnel fixed in a four-necked flask, and dripped at 50°C with stirring, and allowed to stand after the synthesis reaction, and the mixture was poured into a separating funnel. When the resin layer and the solvent layer in the mixture can be completely separated, the supernatant was removed, and a toluene solution was added to dissolve the resin layer below. After the resin was dissolved, it was washed with sodium chloride (NaCl) solution and then with deionized water until the solution was alkaline. Finally, a rotary evaporator was used to slowly heat up to separate the toluene solvent in the solution to obtain a sulfur-containing epoxy resin.

[0044] The epoxy resin includes a sulfur-containing epoxy resin and a sulfur-free epoxy resin, and the mass ratio of the episulfide group to the epoxy group in the epoxy resin is 60:40.

[0045] The photosensitive resin composition comprises, in parts by weight, 100 parts of alkali-soluble resin anhydride-modified o-cresol epoxy acrylic resin (model PR3000, manufactured by Shanghai Showa), 2 parts of photopolymerizable monomer 1,6-hexanediol diacrylate (manufactured by Sartomer, trade name SR238NS), 8 parts of photopolymerizable monomer pentaerythritol tetraacrylate (manufactured by Sartomer, trade name SR295NS), 3 parts of terminal mercapto ester compound pentaerythritol tetra-3-mercaptopropionate (manufactured by Aladdin), 2 parts of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide (manufactured by Changzhou Qiangli, model TR-TPO), 1 1 part of photoinitiator 1-hydroxycyclohexyl phenyl ketone (produced by Changzhou Qiangli, model number TR-184), 1 part of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone (produced by Changzhou Qiangli, model number TR-907), 15 parts of epoxy resin, 2 parts of curing agent maleic anhydride (produced by Aladdin), 20 parts of inorganic filler barium sulfate (produced by Japan Sakai Chemical, model number BF-20), 12 parts of inorganic filler silica (produced by Yishitong, model number NFS-200E), 1.5 parts of carbon black (produced by Bora, model number Raven2500), 1 part of antioxidant (manufacturer: BASF), 0.5 parts of leveling agent (manufacturer: BYK Chemicals), 0.5 parts of defoaming agent octamethylcyclotetrasiloxane (manufacturer: Dow Chemical, model: SH-193) and 30 parts of the second solvent γ-butyrolactone.

[0046] Preparation of photosensitive dry film: According to the above-mentioned weight proportions, the alkali-soluble resin and the auxiliary agent are added to the second solvent and mixed evenly, and ground by a sand mill to a particle size of <10 μm, and then the photopolymerization monomer, photoinitiator, epoxy resin and curing agent are added in sequence and mixed thoroughly, and the photosensitive resin composition is evenly coated on the PET support film by a coater and dried to obtain a photosensitive dry film with a thickness of 25 μm, wherein the drying temperature is 85°C and the drying time is 30 min.

[0047] Example 2

[0048] The difference from Example 1 is that, in parts by weight, the photosensitive resin composition includes: 115 parts of alkali-soluble resin anhydride modified o-cresol epoxy acrylic resin (model PR3000, manufacturer Shanghai Showa), 4 parts of photopolymerizable monomer 1,6-hexanediol diacrylate (manufactured by Sartomer, trade name SR238NS), 10 parts of photopolymerizable monomer pentaerythritol tetraacrylate (manufactured by Sartomer, trade name SR295NS), 10 parts of terminal mercapto ester compound pentaerythritol tetra-3-mercaptopropionate (manufactured by Aladdin), 2 parts of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide (manufactured by Changzhou Qiangli, model TR-T PO), 1 part of photoinitiator 1-hydroxycyclohexyl phenyl ketone (produced by Changzhou Qiangli, model number TR-184), 2 parts of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone (produced by Changzhou Qiangli, model number TR-907), 30 parts of epoxy resin, 7 parts of curing agent maleic anhydride (produced by Aladdin), 25 parts of inorganic filler barium sulfate (produced by Japan Sakai Chemical, model number BF-20), 15 parts of inorganic filler silica (produced by Yishitong, model number NFS-200E), 3.5 parts of carbon black (produced by Bora, model number Raven2500), 2.5 parts of antioxidant (manufacturer: BASF), 2.5 parts of leveling agent (manufacturer: BYK Chemical), 1.5 parts of defoaming agent octamethylcyclotetrasiloxane (manufacturer: Dow Chemical, model: SH-193) and 30 parts of the second solvent γ-butyrolactone, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0049] Example 3

[0050] The difference from Example 1 is that the bisphenol A epoxy resin BNE-186 (Changchun Chemical) is 200 g, and the sulfur-containing compound potassium thiocyanate (KSCN) is 80 g, so that the mass ratio of episulfide groups to epoxy groups in the epoxy resin is 30:70, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0051] Example 4

[0052] The difference from Example 1 is that by adding 80 g of bisphenol A epoxy resin BNE-186 (Changchun Chemical) to adjust the mass ratio of episulfide groups to epoxy groups in the sulfur-containing epoxy resin obtained in Example 1, so that the mass ratio of episulfide groups to epoxy groups in the epoxy resin is 30:70, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0053] Example 5

[0054] The difference from Example 1 is that the mass ratio of the episulfide group and the epoxy group in the sulfur-containing epoxy resin obtained in Example 1 is adjusted by adding 40g of bisphenol A epoxy resin BNE-186 (Changchun Chemical) and 40g of o-cresol epoxy resin CNE-200ELB (Changchun Chemical), so that the mass ratio of the episulfide group and the epoxy group in the epoxy resin is 30:70, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0055] Example 6

[0056] The difference from Example 4 is that the mass ratio of the episulfide group and the epoxy group in the sulfur-containing epoxy resin obtained in Example 1 is adjusted by adding 130 g of bisphenol A epoxy resin BNE-186 (Changchun Chemical) so that the mass ratio of the episulfide group and the epoxy group is 5:95, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0057] Example 7

[0058] The difference from Example 1 is that the mass ratio of the total mass of the terminal thiol ester compound pentaerythritol tetrakis-3-mercaptopropionate and the photopolymerizable monomer (1,6-hexanediol diacrylate and pentaerythritol tetraacrylate) is 0.1:1, wherein, in parts by weight, 1,6-hexanediol diacrylate is 5 parts, pentaerythritol tetraacrylate is 15 parts, and pentaerythritol tetrakis-3-mercaptopropionate is 4 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0059] Example 8

[0060] The difference from Example 1 is that the mass ratio of the total mass of the terminal thiol ester compound pentaerythritol tetrakis-3-mercaptopropionate and the photopolymerizable monomer (1,6-hexanediol diacrylate and pentaerythritol tetraacrylate) is 0.5:1, wherein, in parts by weight, 1,6-hexanediol diacrylate is 2 parts, pentaerythritol tetraacrylate is 6 parts, and pentaerythritol tetrakis-3-mercaptopropionate is 4 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0061] Example 9

[0062] The difference from Example 1 is that the mass ratio of the total mass of the terminal thiol ester compound pentaerythritol tetrakis-3-mercaptopropionate and the photopolymerizable monomer (1,6-hexanediol diacrylate and pentaerythritol tetraacrylate) is 1:1, wherein, in parts by weight, 1,6-hexanediol diacrylate is 2 parts, pentaerythritol tetraacrylate is 4 parts, and pentaerythritol tetrakis-3-mercaptopropionate is 6 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0063] Example 10

[0064] The difference from Example 1 is that the photopolymerizable monomer is a combination of a difunctional monomer 1,6-hexanediol diacrylate, a trifunctional monomer (3) ethoxylated trimethylolpropane triacrylate, a tetrafunctional monomer pentaerythritol tetraacrylate, and a hexafunctional monomer dipentaerythritol hexaacrylate, and the ratio of the total mass of the difunctional monomer 1,6-hexanediol diacrylate and the trifunctional monomer (3) ethoxylated trimethylolpropane triacrylate to the total mass of the tetrafunctional monomer pentaerythritol tetraacrylate and the hexafunctional monomer dipentaerythritol hexaacrylate is 0.3:3, wherein, in parts by weight, 1,6-hexanediol diacrylate is 0.5 parts, (3) ethoxylated trimethylolpropane triacrylate is 1 part, pentaerythritol tetraacrylate is 4 parts, and pentaerythritol hexaacrylate is 11 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0065] Embodiment 11

[0066] The difference from Example 1 is that the photopolymerizable monomer is a combination of a difunctional monomer 1,6-hexanediol diacrylate, a trifunctional monomer (3) ethoxylated trimethylolpropane triacrylate, a tetrafunctional monomer pentaerythritol tetraacrylate, and a hexafunctional monomer dipentaerythritol hexaacrylate, and the ratio of the total mass of the difunctional monomer 1,6-hexanediol diacrylate and the trifunctional monomer (3) ethoxylated trimethylolpropane triacrylate to the total mass of the tetrafunctional monomer pentaerythritol tetraacrylate and the hexafunctional monomer dipentaerythritol hexaacrylate is 0.7:1.2, wherein, in parts by weight, 1,6-hexanediol diacrylate is 2 parts, (3) ethoxylated trimethylolpropane triacrylate is 5 parts, pentaerythritol tetraacrylate is 5 parts, and pentaerythritol hexaacrylate is 7 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0067] Example 12

[0068] The difference from Example 1 is that the photopolymerizable monomer is a combination of a difunctional monomer 1,6-hexanediol diacrylate, a trifunctional monomer (3) ethoxylated trimethylolpropane triacrylate, a tetrafunctional monomer pentaerythritol tetraacrylate, and a hexafunctional monomer dipentaerythritol hexaacrylate, and the ratio of the total mass of the difunctional monomer 1,6-hexanediol diacrylate and the trifunctional monomer (3) ethoxylated trimethylolpropane triacrylate to the total mass of the tetrafunctional monomer pentaerythritol tetraacrylate and the hexafunctional monomer dipentaerythritol hexaacrylate is 1:1.2, wherein, in parts by weight, 1,6-hexanediol diacrylate is 4 parts, (3) ethoxylated trimethylolpropane triacrylate is 6 parts, pentaerythritol tetraacrylate is 5 parts, and pentaerythritol hexaacrylate is 7 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0069] Example 13

[0070] The difference from Example 1 is that the mass ratio of the curing agent maleic anhydride to the sulfur-containing epoxy resin is 2:25, wherein, by weight, maleic anhydride is 2 parts and the sulfur-containing epoxy resin is 25 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0071] Embodiment 14

[0072] The difference from Example 1 is that the mass ratio of the curing agent maleic anhydride to the sulfur-containing epoxy resin is 5:15, wherein, by weight, maleic anhydride is 5 parts and the sulfur-containing epoxy resin is 15 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0073] Embodiment 15

[0074] The difference from Example 1 is that the mass ratio of the curing agent maleic anhydride to the sulfur-containing epoxy resin is 6:15, wherein, by weight, maleic anhydride is 6 parts and the sulfur-containing epoxy resin is 15 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0075] Example 16

[0076] The difference from Example 1 is that the inorganic fillers are barium sulfate and silicon dioxide, and the functional additives are carbon black and antioxidants. Leveling agent and defoaming agent octamethylcyclotetrasiloxane, the second solvent is γ-butyrolactone, in parts by weight, the total number of inorganic fillers is 15 parts, the total number of functional additives is 2 parts, and the number of the second solvent is 30 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0077] Embodiment 17

[0078] The difference from Example 1 is that the inorganic fillers are barium sulfate and silicon dioxide, and the functional additives are carbon black and antioxidants. Leveling agent and defoaming agent octamethylcyclotetrasiloxane, the second solvent is γ-butyrolactone, in parts by weight, the total number of inorganic fillers is 45 parts, the total number of functional additives is 2 parts, and the number of the second solvent is 30 parts, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0079] Comparative Example 1

[0080] The difference from Example 4 is that pentaerythritol tetrakis-3-mercaptopropionate, a terminal mercapto ester compound, is not added, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0081] Comparative Example 2

[0082] The difference from Example 4 is that 15 parts of pentaerythritol tetrakis-3-mercaptopropionate (manufactured by Aladdin), a terminal mercapto ester compound, is added to finally obtain a photosensitive resin composition and a photosensitive dry film.

[0083] Comparative Example 3

[0084] The difference from Example 4 is that the sulfur-containing epoxy resin is replaced by bisphenol A epoxy resin BNE-186 (Changchun Chemical), and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0085] Comparative Example 4

[0086] The difference from Example 4 is that the curing temperature is 150° C. and the curing time is 1 hour, and finally a photosensitive resin composition and a photosensitive dry film are obtained.

[0087] Test method:

[0088] Testing method for the mass ratio of episulfide groups to epoxy groups in sulfur-containing epoxy resins: testing by infrared spectroscopy or nuclear magnetic resonance quantitative analysis.

[0089] 1) Sensitivity test:

[0090] A 25μm photosensitive dry film was attached to a commercial copper-clad laminate using a vacuum laminator. The pressure in the vacuum section was 6kgf, the vacuum time was 20s, the pressing time was 30s, and the temperature was 65°C; the pressure in the leveling section was 6kgf, the leveling time was 50s, and the temperature was 85°C. After the attachment was completed, it was exposed and developed on the ST21 step exposure scale. The lowest energy that was not developed and completely exposed on the ST8 step was the sensitivity energy of the formula.

[0091] 2) Line width and spacing (L / S), side erosion and minimum window opening test:

[0092] A 25μm photosensitive dry film is attached to a commercial copper-clad laminate using a vacuum laminator. The pressure in the vacuum section is 6kgf, the vacuum time is 20s, the pressing time is 30s, and the temperature is 65℃; the pressure in the flattening section is 6kgf, the flattening time is 50s, and the temperature is 85℃. After the attachment is completed, the standard test mask film is exposed at ST8 / 21 sensitivity energy. After thermal curing, the L / S and side etching are observed under a metallographic microscope through slicing, and the minimum window can be directly observed under a metallographic microscope. When the line width, line spacing, and window diameter can be fully presented and the error between them and the standard mask film is within ±5%, it is the optimal L / S and minimum window that can be achieved. At this time, the size of the side etching is measured and recorded to observe whether the side etching is within ±5% of the standard mask film. Among them, the test results are divided into the following levels: Level 1: error within ±5%; Level 2: error outside ±5% and within ±10%; Level 3: error outside ±10%.

[0093] 3) Surface flatness test after thermal curing:

[0094] A 25 μm photosensitive dry film was attached to a commercial copper-clad laminate using a vacuum laminating machine. The pressure of the vacuum section was 6 kgf, the vacuum time was 20 s, the pressing time was 30 s, and the temperature was 65 ° C; the pressure of the flattening section was 6 kgf, the flattening time was 50 s, and the temperature was 85 ° C. After the attachment was completed, the commercial copper-clad laminate attached with the photosensitive dry film was exposed under a high-pressure mercury lamp exposure machine, and the PET support film was peeled off and exposed with appropriate energy. After exposure, it was placed at room temperature for 30 minutes and then developed at 30 ° C for 30 seconds with an alkaline developer (1wt% sodium carbonate aqueous solution). After development, the developer remaining on the film surface was rinsed with water for 30 seconds, and then the copper-clad laminate with the film attached was post-cured in an oven at 150 ° C for 30 minutes. Observe whether the cured film on the copper-clad laminate has cracks, wrinkles, and warping under a microscope. The test results are graded as follows: Level 1: The surface is flat, without wrinkles, cracks or warping; Level 2: The surface has wrinkles, cracks or warping.

[0095] 4) Glass transition temperature (Tg) and coefficient of thermal expansion (CTE) test:

[0096] A 50 μm thick photosensitive dry film was attached to a commercial copper-clad laminate using a vacuum laminating machine. The pressure of the vacuum section was 6 kgf, the vacuum time was 20 s, the lamination time was 30 s, and the temperature was 65 ° C; the pressure of the flattening section was 6 kgf, the flattening time was 50 s, and the temperature was 85 ° C. After the attachment was completed, the whole board was exposed using ST8 / 21 sensitivity energy. After exposure, it was placed at room temperature for 30 min and then developed at 30 ° C for 30 s using an alkaline developer (1 wt% sodium carbonate aqueous solution). After development, it was rinsed with water for 30 s to remove the residual developer on the surface of the film, and then the copper-clad laminate with the film attached was post-cured in an oven at 150 ° C for 30 min. Then, after cutting it into 5 mm wide and 25 mm long with a cutting knife, the PET support film of the cured film product was peeled off to obtain a cured photosensitive resin composition for thermal expansion coefficient evaluation. The thermal expansion coefficient in the tensile mode was measured using a TMA device (TMAQ400, Shenzhen Shante Technology). The tensile load is 0.1N, the span (distance between chucks) is 15mm, and the heating rate is 10℃ / min. First, install the sample on the device, heat it from room temperature (25℃) to 160℃, and leave it for 15min. Then, cool it to -60℃, and measure it again under the condition of heating from -60℃ to 250℃ at a heating rate of 10℃ / min. Mark the inflection point seen in the range from 25℃ to 200℃ as Tg, and record the temperature at this time. CTE uses the slope of the tangent of the curve obtained at a temperature below Tg. Among them, the test results are graded as follows: Level 1: less than 50ppm / ℃; Level 2: 50~60ppm / ℃; Level 3: 60~70ppm / ℃; Level 4: more than 70ppm / ℃.

[0097] 5) Aging (HAST) test:

[0098] A 25 μm thick photosensitive dry film was attached to a commercial copper clad laminate using a vacuum laminator. The pressure in the vacuum section was 6 kgf, the vacuum time was 20 s, the pressing time was 30 s, and the temperature was 65°C; the pressure in the leveling section was 6 kgf, the leveling time was 50 s, and the temperature was 85°C. After the attachment was completed, the entire board was exposed using ST8 / 21 sensitivity energy. After exposure, it was placed at room temperature for 30 minutes and then developed at 30°C for 30 seconds using an alkaline developer (1 wt% sodium carbonate aqueous solution). After development, it was rinsed with water for 30 seconds to remove the residual developer on the surface of the film, and then the copper clad laminate with the film attached was post-cured in an oven at 150°C for 30 minutes. The resistivity of the cured film product before and after HAST treatment was tested with a resistance meter, and then the sample was moved to the HAST chamber (PC-422R8D, Hirayama Manufacturing Co., Ltd.), and placed at 121°C and 100% humidity for 120 hours. The resistivity after HAST treatment was tested again, and whether there was any bubble peeling or other phenomena, and the resistivity changes before and after HAST were compared. Among them, the test results were graded as follows: Level 1: No bubble peeling or other phenomena, or the resistivity changes within ±10%; Level 2: No bubble peeling or other phenomena, or the resistivity changes within ±30%; Level 3: The cured film has a small amount of bubbling, peeling, or even falling off; Level 4: There are a lot of bubbles or falling off, or the resistivity changes>50%.

[0099] 6) Acid resistance test:

[0100] The test samples were prepared by the above HAST test preparation method and immersed in 10 vol% H 2 SO 4 After 30 minutes in the aqueous solution, rinse with clean water and dry. Then use 3M tape for peeling test. Acid resistance is evaluated according to the following standards. The test results are graded as follows: Level 1: The cured film has no bubbling, peeling, or even falling off; Level 2: The cured film has a small amount of bubbling, no peeling, and no falling off; Level 3: The cured film has a small amount of bubbling, peeling, or even falling off; Level 4: The cured film has a large amount of falling off.

[0101] 7) Alkali resistance test:

[0102] The test sample was prepared by the preparation method of the above HAST test, immersed in a 10 vol% NaOH aqueous solution at 30°C for 30 minutes, rinsed with clean water and dried. Then a peeling test was performed with 3M tape. Alkali resistance was evaluated according to the following standards. The test results were graded as follows: Level 1: The cured film had no bubbling, peeling, or even shedding; Level 2: The cured film had a small amount of bubbling, no peeling, and no shedding; Level 3: The cured film had a small amount of bubbling, peeling, or even shedding; Level 4: The cured film had a large amount of shedding.

[0103] 8)Solvent resistance test:

[0104] The test sample was prepared by the preparation method of the HAST test, immersed in propylene glycol methyl ether acetate solvent for 30 minutes at 30°C, taken out and dried, and then peeled with 3M tape to evaluate the solvent resistance according to the following standards. The test results are graded as follows: Level 1: The cured film has no bubbling, peeling, or even falling off; Level 2: The cured film has a small amount of bubbling, no peeling, and no falling off; Level 3: The cured film has a small amount of bubbling, peeling, or even falling off; Level 4: The cured film has a large amount of falling off.

[0105] 9) Heat resistance test:

[0106] Test according to IPC-TM650.2.6.8 standard. After the cured film is immersed in rosin flux for 30 seconds, it is vertically immersed in a tin furnace at a temperature of 288°C for 10 seconds, and repeated 3 times. Observe whether the surface is bubbling, discolored, or floating, and observe whether the cured film falls off by peeling off the 3M tape, and evaluate the changes in appearance based on the following criteria. The test results are graded as follows: Level 1: The cured film has no bubbling, peeling, or even falling off; Level 2: The cured film has a small amount of bubbling, no peeling, and no falling off; Level 3: The cured film has a small amount of bubbling, peeling, or even falling off; Level 4: The cured film has a large amount of falling off.

[0107] The cured films obtained in the above examples and comparative examples were subjected to the above performance tests. The test results are shown in Tables 1 and 2.

[0108] Table 1

[0109]

[0110]

[0111] Table 2

[0112]

[0113]

[0114] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0115] The photosensitive resin composition of the present application uses an alkali-soluble resin as a base, and the addition of a photopolymerizable monomer and a photoinitiator can cause the photosensitive resin composition to undergo a polymerization reaction under light; the terminal mercapto ester compound can be used as a monomer component to react with an olefinic unsaturated bond, thereby increasing the sensitivity of the photosensitive resin composition and reducing the energy of the photosensitive resin composition during the photocuring process, thereby significantly reducing the exposure time of the photocuring process; the sulfur-containing epoxy resin is used as a heat-curing component in the photosensitive resin composition, and the thiol (-SH) or sulfur anion (S) generated by the ring-opening of the episulfide group in the sulfur-containing epoxy resin under heating conditions - ) can promote the ring opening of epoxy groups, thereby promoting the curing reaction between epoxy resin, curing agent and alkali-soluble resin, and thus improving the cross-linked network structure density, modulus and glass transition temperature of the photosensitive resin composition after curing. By controlling the type and content of each component of the photosensitive resin composition of the present application within the above range, even if the curing time is short in the photocuring and thermal curing process, the surface layer and deep layer of the cured film can be uniformly cured, and at the same time, it also has high sensitivity, heat resistance and good developing performance.

[0116] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A photosensitive resin composition, characterized in that: In parts by weight, the photosensitive resin composition comprises: 100-115 parts of alkali-soluble resin; 5 to 20 parts of photopolymerizable monomer; 3 to 10 parts of terminal mercapto ester compounds; 1 to 5 parts of a photoinitiator; and 10-30 parts of epoxy resin; Wherein, the epoxy resin includes sulfur-containing epoxy resin.

2. The photosensitive resin composition according to claim 1, characterized in that: The mass ratio of the terminal mercapto ester compound to the photopolymerizable monomer is 0.1-0.5:1; preferably, the weight portion of the terminal mercapto ester compound is 4-7 parts, and / or the weight portion of the epoxy resin is 15-25 parts.

3. The photosensitive resin composition according to claim 1 or 2, characterized in that: The epoxy resin also includes sulfur-free epoxy resin: Wherein, taking the sum of the mass contents of the episulfide groups and the epoxy groups in the epoxy resin as 100%, the mass ratio of the episulfide groups to the epoxy groups is 15-70:30-85, preferably 15-40:60-85.

4. The photosensitive resin composition according to any one of claims 1 to 3, characterized in that: The photopolymerizable monomer is a multifunctional acrylate, preferably, the photopolymerizable monomer is selected from any one or more of a difunctional monomer, a trifunctional monomer, a tetrafunctional monomer, a pentafunctional monomer and a hexafunctional monomer; Preferably, the difunctional monomer is selected from any one or more of tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, (10) ethoxylated bisphenol A diacrylate, (10) propoxylated bisphenol A diacrylate, (10) ethoxylated propoxylated bisphenol A diacrylate, (4) ethoxylated bisphenol A diacrylate, (4) propoxylated bisphenol A diacrylate, ethoxylated propoxylated bisphenol A diacrylate and tricyclodecane dimethanol diacrylate; Preferably, the trifunctional monomer is selected from any one or more of trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, (3) ethoxylated trimethylolpropane triacrylate, (3) propoxylated trimethylolpropane triacrylate, (3) ethoxylated propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, (3) propoxylated trimethylolpropane triacrylate, ethoxylated propoxylated trimethylolpropane triacrylate, (6) ethoxylated trimethylolpropane triacrylate, (6) propoxylated trimethylolpropane triacrylate and (6) ethoxylated propoxylated trimethylolpropane triacrylate; Preferably, the tetrafunctional monomer is selected from any one or more of pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate and ethoxylated propoxylated pentaerythritol tetraacrylate; Preferably, the pentafunctional monomer is dipentaerythritol pentaacrylate; Preferably, the hexafunctional monomer is dipentaerythritol hexaacrylate; And / or, the ratio of the total mass of the difunctional monomer and the trifunctional monomer in the photopolymerizable monomer to the total mass of the tetrafunctional monomer and the hexafunctional monomer is 0.3-0.7:1.2-3; and / or, the mass ratio of the difunctional monomer and the trifunctional monomer is 0.1-0.3:0.5-1, and / or, the mass ratio of the tetrafunctional monomer and the hexafunctional monomer is 0.3-0.5:0.6-1.

5. The photosensitive resin composition according to any one of claims 1 to 4, characterized in that: The terminal thiol-containing ester compound is an ester compound containing a terminal thiol group, and preferably the terminal thiol-containing ester compound is selected from any one or more of isooctyl thioglycolate, pentaerythritol tetrakis-3-mercaptopropionate, ethylene glycol bisthioglycolate, glycerol thioglycolate, ethyl thioglycolate, butyl thioglycolate, isopropyl thioglycolate, methyl 3-mercaptopropionate, butyl 3-mercaptopropionate and trimethylolpropane tris(3-mercaptopropionate); And / or, the alkali-soluble resin is a carboxyl-containing epoxy acrylic resin; preferably, the alkali-soluble resin is selected from any one or more of an acid-modified bisphenol A epoxy acrylic resin, an acid-modified bisphenol F epoxy acrylic resin, an acid-modified alicyclic epoxy acrylic resin and an acid-modified phenolic epoxy acrylic resin; And / or, the photoinitiator is a free radical photoinitiator and / or a cationic photoinitiator; preferably, the free radical photoinitiator is selected from 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, 2-isopropylthioxanthone, 1-hydroxycyclohexylphenyl ketone, benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, tetramethylthrone, tetraethylthrone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2,4-diethylthioxanthone, benzoin dimethyl ether, 2-hydroxy-methylphenyl Any one or more of propane-1-one, ethyl 4-(N,N-dimethylamino)benzoate and 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone; and / or, the cationic photoinitiator is selected from any one or more of triphenylsulfonium hexafluorophosphate, 4-phenylthiophenyl diphenylsulfonium salt, 4-dodecyloxyphenyl diphenylsulfonium hexafluoroantimonate, bis[(4-diphenylsulfonium)benzene] sulfide-bis-hexafluorophosphate, 4-phenylthiophenyl diphenylsulfonium salt, (4-hydroxyphenyl)methyl (benzyl) hexasulfonium fluorophosphate, 4-acetoxyphenyl dimethylsulfonium hexafluoroantimonate and diphenyliodonium hexafluorophosphate.

6. The photosensitive resin composition according to claim 3, characterized in that: The method for preparing the sulfur-containing epoxy resin comprises: reacting raw materials including the sulfur-free epoxy resin, a sulfur-containing compound and a first solvent to obtain the sulfur-containing epoxy resin; Wherein, the sulfur-containing compound is potassium thiocyanate and / or thiourea; And / or, the sulfur-free epoxy resin is a multifunctional resin, preferably the sulfur-free epoxy resin is selected from any one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, novolac epoxy resin, aliphatic glycidyl ether resin, brominated epoxy resin, glycidyl phthalate, glycidylamine epoxy resin, alicyclic epoxy resin, epoxidized olefin, hydantoin epoxy resin and imide epoxy resin; And / or, the first solvent is water and / or ethanol solution; and / or, the mass ratio of the sulfur-free epoxy resin to the sulfur-containing compound is 150-200:50-80; And / or, the reaction temperature is 50-70° C.; and / or, the reaction time is 300-600 min.

7. A photosensitive dry film, obtained by coating and drying a photosensitive resin composition, characterized in that: The photosensitive resin composition is the photosensitive resin composition according to any one of claims 1 to 6.

8. A cured film, obtained by coating, drying and curing the composition in sequence, or obtained by curing a photosensitive dry film, characterized in that: The composition is the photosensitive resin composition according to any one of claims 1 to 6, the photosensitive dry film is the photosensitive dry film according to claim 7, wherein the curing includes photocuring, thermal curing or photo-thermal dual curing.

9. A circuit board comprising a cured film, characterized in that: The cured film is the cured film according to claim 8.

10. A display module, comprising a cured film, characterized in that: The cured film is the cured film according to claim 8.

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