Low-temperature negative photoresist composition

Abstract

The invention discloses a low-temperature negative photoresist composition, which is characterized in that light-cured resin synthesized by terminal epoxy, four-membered ring epoxy groups and a comonomer has different ring tension and different ring-opening activation energy due to the fact that the ring tension of the epoxy groups is different, and the low-temperature negative photoresist composition is matched with an imidazole-derived medium-temperature (50-100 DEG C) curing accelerator to be used, so that the low-temperature negative photoresist composition has the advantages that the low-temperature negative photoresist composition can be applied to a light-cured film; and the ring-opening addition reaction of the epoxy group is promoted under the low-temperature condition (80-120 DEG C), so that a cured film is formed through sufficient crosslinking, and the low-temperature cured film formed by the photoresist composition has excellent adhesiveness and chemical resistance. The negative photosensitive resin composition provided by the invention can perform curing reaction at low temperature, and the formed cured film has good adhesiveness and chemical resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor photoresists, and particularly relates to a negative photoresist composition for low temperature. Background Art

[0002] In the field of display panels, the lithography process is the core process in display panel manufacturing, and the photoresist therein plays an important role. With the iterative update of technology, flexible display screens are applied to a wider range of fields due to the freedom in design, and at the same time, the lithography process applicable to flexible panel manufacturing has been further developed and improved.

[0003] Compared with the production of traditional display screens, there are many technical improvements in the production of flexible display screens. For example, in the production of liquid crystal display (LCD) and organic light-emitting diode (OLED) flexible display screens, polymer films are used instead of traditional glass substrates. Polymer films have poorer heat resistance than glass substrates, which further requires the flexible panel to be manufactured at low temperatures. The photosensitive resin composition used for the planarization interlayer insulating film of the color filter also needs to be cured at low temperatures. After traditional photosensitive resin compositions are cured at low temperatures (150 °C), there are problems such as insufficient curing degree, reduced adhesion and chemical resistance. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a negative photoresist composition for low temperature. The present invention is a negative photosensitive resin composition capable of undergoing a curing reaction at low temperatures, and the formed cured film has good adhesion and chemical resistance.

[0005] To achieve the above technical objectives, the present invention will adopt the following technical solutions: A negative photoresist composition for low temperature, comprising the following components by mass percentage: 20 - 80% of a photocurable resin, 5 - 60% of a photopolymerizable monomer, 0.1 - 4.0% of a photopolymerization initiator, 0.1 - 10% of a curing accelerator, and 0.1 - 0.5% of an additive, and the sum of the component contents is 100%;

[0006] And an appropriate amount of solvent;

[0007] The photocurable resin is a copolymer synthesized by free radical polymerization of an unsaturated carboxylic acid, a carboxylic anhydride, and an olefinic unsaturated compound.

[0008] Preferably, the photocurable resin consists of the following monomers by weight:

[0009] 10 - 50 parts of the unsaturated carboxylic acid monomer methacrylic acid;

[0010] 50 - 90 parts of an unsaturated olefin compound having a terminal epoxy group and / or a four-membered ring epoxy group;

[0011] 10 - 20 parts of an unsaturated olefin compound with an aromatic ring,

[0012] Obtained by a polymerization reaction under the action of a solvent and an initiator.

[0013] Preferably, the unsaturated carboxylic acid monomer is selected from methacrylic acid, acrylic acid, maleic acid, fumaric acid, aconitic acid, and crotonic acid;

[0014] The unsaturated olefin compound having a terminal epoxy group and / or a four-membered ring epoxy group consists of glycidyl methacrylate with a terminal epoxy group and 3,4-epoxycyclobutyl methacrylate with a four-membered ring epoxy group;

[0015] The unsaturated olefin compound with an aromatic ring is selected from styrene and its derivatives.

[0016] Preferably, the molecular weight of the photocurable resin is 2000 - 40000, preferably 5000 - 30000.

[0017] Preferably, the synthesis method of the photocurable resin is as follows: In a solvent, 25 parts by weight of methacrylic acid, 40 parts by weight of glycidyl methacrylate with a terminal epoxy group, 20 parts by weight of 3,4-epoxycyclobutyl methacrylate with a four-membered ring epoxy group, and 15 parts by mass of styrene are added in sequence. After stirring well, 12 parts by weight of the initiator 2,2'-azobis(2,4-dimethylvaleronitrile) is added. The mixture is heated and kept warm at about 70 ± 2 °C, and after reacting for 5 hours, it is cooled to room temperature. After filtration and distillation, a photocurable resin with a solid content of 32.1% is obtained, and its weight average molecular weight (Mw) is 11205.

[0018] Preferably, the photopolymerizable monomer is one or a combination of more than one of trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate modified or unmodified with succinic anhydride.

[0019] Preferably, the curing accelerator includes 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and their derivatives.

[0020] Preferably, the photopolymerization initiator is a radical photopolymerization initiator.

[0021] Preferably, the radical photopolymerization initiator includes acetophenone and its derivatives, biimidazole and its derivatives, triazine compounds, or oxime-based compounds.

[0022] Preferably, the acetophenone and its derivatives include 2-hydroxy-2-methyl-1-[4-(1-methylethenyl)phenyl]propan-1-one, 4,4-bis-(diethylamino)-benzophenone, and 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methylpropan-1-one.

[0023] Preferably, the triazine compounds include 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine and 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine.

[0024] Preferably, the biimidazole and its derivatives include 2,2'-bis(2,3-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole and 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(trialkoxyphenyl)biimidazole.

[0025] Preferably, the oxime compounds include: OXE-1: 1-(4-phenylthiophenyl)octane-1,2-dione-2-benzoyl oxime ester; OXE-2: 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyl oxime).

[0026] Advantageous effects: Compared with the prior art, the present invention provides a negative photosensitive resin composition capable of curing under low-temperature conditions, and the cured film formed thereby has good adhesion and chemical resistance. Specific embodiments

[0027] The following further clarifies the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the present invention, various equivalent modifications made by those skilled in the art fall within the scope defined by the appended claims of this application.

[0028] I. Composition of the negative photosensitive resin The object of the present invention is to provide a negative photosensitive resin composition capable of curing under low-temperature conditions, and the cured film formed thereby has good adhesion and chemical resistance. The negative photosensitive resin composition provided by the present invention includes: (A) a photocurable resin, (B) a photopolymerizable monomer, (C) a solvent, (D) a photoinitiator, (E) a curing accelerator, and (F) an additive. The following details each component in the negative photosensitive resin composition of the present invention.

[0030] (A) Photocurable resin

[0031] The photocurable resin in the present invention contains unsaturated structural units derived from carboxyl or hydroxyl groups, and is a copolymer synthesized by free radical polymerization of unsaturated carboxylic acid monomers, unsaturated olefin compounds having epoxy groups, and unsaturated olefin compounds having aromatic rings. Among them:

[0032] (1) Unsaturated carboxylic acid monomers may include acrylic acid, methacrylic acid, maleic acid, fumaric acid, aconitic acid, crotonic acid, etc., and it is further preferred to use methacrylic acid and acrylic acid. When its weight fraction (based on 100 parts in total of all copolymer monomers used in resin synthesis) is 10 to 50 parts by weight, the resin composition has good solubility in an alkaline developer.

[0033] (2) For the copolymer monomer of unsaturated olefin compounds having epoxy groups, monomers with terminal epoxy groups and quaternary ring epoxy groups are preferably used. More precisely, glycidyl methacrylate with a terminal epoxy group and oxetane methacrylate with a quaternary ring epoxy group are used as copolymer monomers. The weight fraction of such olefin compounds is preferably 50 to 90 parts by weight. The ring-opening activation energies of epoxy groups with different ring tensions are different, which enables the resin composition to form a cured film during pre-baking and further increase the cross-linking degree during post-baking.

[0034] (3) Unsaturated olefin compounds with aromatic rings can improve the mechanical strength of the cured film formed after curing the resin composition. In the examples of the present invention, styrene and its derivatives are preferably used. The weight fraction of such olefin compounds should be preferably 10 to 20 parts by weight.

[0035] It is advisable that the weight average molecular weight (Mw) of the photocurable resin (A) used in the present invention is between 2000 and 40000. When the weight average molecular weight of the said photocurable resin is below 2000, problems such as a decrease in the residual film rate, poor development patterns, and insufficient performance of the formed organic insulating film may occur; while when its weight average molecular weight is above 40000, problems such as poor pattern development will occur in the formed organic insulating film.

[0036] Furthermore, as a preferred solution, the weight average molecular weight of the photocurable resin is in the range of 5000 to 30000. The resin within this range has appropriate viscosity (usually 10 - 35 cP), excellent adhesion to the substrate, and excellent developability.

[0037] (B) Photoinitiator monomer

[0038] The types and amounts of the photopolymerizable monomers in the negative-type low-temperature photoresist composition of the present invention are not particularly limited, and compounds containing two or more radical polymerization functional groups are preferred. More preferably, they are polyfunctional (meth)acryloyl compounds. As a preference, succinic anhydride-modified or unmodified pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and combinations of two or more of them can be used. Based on 100 parts in total of the solid content of the resin composition, the weight parts of the photopolymerizable monomer are preferably from 5 to 50 parts by weight, more preferably from 8 to 45 parts by weight.

[0039] (C) Solvent

[0040] The negative-type low-temperature photoresist composition of the present invention can be prepared in the form of a liquid composition in which the above components are mixed with a solvent. The amount of the solvent in the negative-type low-temperature photoresist composition according to the present invention is not particularly limited. For example, a solvent can be used such that, based on 100 parts by weight of the total weight of the composition, the solid content is 10 to 70 parts by weight, preferably 15 to 60 parts by weight. The solid content refers to the components constituting the composition excluding the solvent. If the amount of the solvent is within the above range, the composition can be easily coated, and its fluidity can be maintained at an appropriate level.

[0041] Specific examples of the solvent include methanol, ethanol, tetrahydrofuran, dioxane, methyl cellosolve acetate, ethyl cellosolve acetate, ethyl acetoacetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol butyl ether acetate, toluene, xylene, methyl ethyl ketone, 4-hydroxy-4-methyl-2-pentanone, cyclopentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, etc.

[0042] Considering the use process of the composition, the solvent used in the present invention is preferably an organic solvent with a boiling point lower than 180°C. Based on the above, preferably propylene glycol monoalkyl ethers, propylene glycol alkyl ether acetates, etc. Specifically, preferably dipropylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol methyl ether acetate. The solvents exemplified above can be used alone or in combination of two or more of them.

[0043] (D) Photoinitiator

[0044] The photoresist composition of the present invention may further comprise a photoinitiator. The photoinitiator referred to in the present invention means a component that generates active groups capable of initiating the polymerization of the photocurable resin (A) and the photopolymerizable monomer (B) through exposure to visible light, ultraviolet light, electron beams, etc. In order for the present photoresist composition to be cured under low-temperature conditions and have good adhesion and chemical resistance after curing and film formation, the photoinitiator used in the present invention includes both a radical photoinitiator and an ionic photoinitiator. The radical initiator can promote the crosslinking of photocurable functional groups in the resin composition, while the ionic initiator can promote the crosslinking reaction of epoxy groups of thermosetting functional groups in the resin composition, further ensuring that the resin composition can undergo a crosslinking reaction at low temperature.

[0045] The photoinitiator used in the present invention may be a compound based on the acetophenone series, a derivative compound based on benzimidazole, a triazine compound, and an oxime compound, or a mixture of one or more of these compounds. Among them, examples of acetophenone compounds having good use effects that can be listed based on the present invention are: 2-hydroxy-2-methyl-1-[4-(1-methylethenyl)phenyl]propan-1-one, 4,4-bis-(diethylamino)-benzophenone, and 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methylpropan-1-one, etc.; triazine compounds are: 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine and 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, etc.; benzimidazole-based compounds are: 2,2'-bis(2,3-dichlorophenyl)-4,4',5,5'-tetraphenylbenzimidazole and 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(trialkoxyphenyl)benzimidazole, etc.; oxime-based compounds are: 1-[9-ethyl-6-benzoyl-9H-carbazol-3-yl]-1,2-nonan-2-oxime-O-benzoate and 1-[9-ethyl-6-benzoyl-9H-carbazol-3-yl]-octan-1-one oxime-O-acetate, etc. Further preferably, OXE-1 and OXE-2 commercially available from BASF can be used.

[0046] Regarding the addition amount of the photoinitiator of the present invention, in the present invention, it is preferably 0.1 to 4.0 parts by weight based on 100 parts by weight of the solid content (mass excluding the solvent) of the resin composition.

[0047] (E) Curing accelerator

[0048] To further improve the curing and film-forming rate and efficiency of the resin composition, a curing accelerator is added to the composition to improve the sensitivity of the resin composition and further enhance its production efficiency. The curing accelerator mainly promotes cross-linking reactions with the aforementioned epoxy groups, and the curing accelerator may include compounds such as polyamines, acid anhydrides, polyphenols, and polythiols. To achieve the effect of low-temperature curing, the curing accelerator of the present invention is preferably an alicyclic polyamine, a tertiary amine, an imidazole compound, etc.

[0049] In the present invention, the curing accelerator used is further preferably an imidazole-derived compound. Examples that can be cited include: 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and their derivatives, etc., but are not limited thereto. The amount of the curing accelerator used is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the solid content (mass excluding the solvent) of the resin composition in the present invention.

[0050] (F) Additives

[0051] The additives of the present invention include surfactants to enhance its coatability when needed; leveling agents can be further included to improve the leveling property of the product, etc. Fluorine-based surfactants, silicon-based surfactants, non-ionic surfactants, etc. can be included. The leveling agents can be selected from commercially available products such as R-08, R-475, R-30 of DIC Corporation, or SH-28PA, SH-190, SH-193 manufactured by Toray Silicone Co., Ltd., etc., but are not limited thereto.

[0052] II. Preparation of the cured film

[0053] The cured film can be formed by methods known in the art. For example, a method in which a photoresist composition is coated on a substrate and then cured. More specifically, in the curing step, most of the solvent can be removed from the photoresist composition coated on the substrate by means of reduced pressure, and then pre-baked at a temperature of 60°C to 130°C to form a preliminary film; then exposed using a photomask with a desired pattern; and developed using a developer (such as a potassium hydroxide solution) to form a pattern on the coating. Thereafter, if necessary, the patterned coating is post-baked at a temperature of 80°C to 120°C for 10 minutes to 5 hours to prepare the desired cured film. The exposure can be carried out at a wavelength of 365 nm as a reference in a wavelength band of 200 to 500 nm at an exposure rate of 10 to 200 mJ / cm2. According to the method of the present invention, the desired pattern can be easily formed from a process perspective.

[0054] Example 1

[0055] (1) Synthesis of the photocurable resin (A)

[0056] In a flask equipped with heating, condensation, thermometer and stirring devices, 300 g of propylene glycol methyl ether acetate solvent was placed, and stirring was continued. Subsequently, 25 parts by weight of an unsaturated carboxylic acid monomer, methacrylic acid, 40 parts by weight of an unsaturated olefin monomer containing an epoxy group, glycidyl methacrylate with a terminal epoxy group, 20 parts by weight of methacrylic acid oxetanyl ester having a four-membered ring epoxy group, and 15 parts by weight of an aromatic ring unsaturated monomer, styrene, were respectively added to the flask. After thorough stirring, 50 g of propylene glycol methyl ether acetate solution dissolving 12 parts by weight of a polymerization initiator, 2,2'-azobis(2,4-dimethylvaleronitrile), was continuously added dropwise. It was heated and maintained at about 70 ± 2 °C, and after reacting for 5 hours, it was cooled to room temperature. After filtration and distillation, a photocurable resin with a solid content of 32.1% was obtained, and its weight average molecular weight (Mw) was 11205.

[0057] (2) Preparation of a negative photoresist composition at low temperature

[0058] 15 g of a photocurable resin (A), 3 g of a photopolymerizable monomer (B), dipentaerythritol hexaacrylate, 1 g of a photoinitiator (D), OXE-02, 0.5 g of a curing accelerator (E), 2-methylimidazole, and 0.02 g of a surfactant (F), Asahi Glass Co., Ltd. S-112, were uniformly mixed. The mixture was dissolved in a solvent of propylene glycol methyl ether acetate, and the viscosity of the photosensitive resin composition was adjusted to be in the range of 10 - 35 cp, and the solid content of the mixture was made to be 14% by weight. The solution was stirred for 2 hours and filtered through a membrane filter with a pore size of 0.2 μm to obtain a composition solution with a solid content of 14% by weight.

[0059] Comparative Example 1

[0060] Compared with Example 1, the difference in this example is that: in the synthesis of the photocurable resin (A), the unsaturated olefin monomer containing an epoxy group only contains glycidyl methacrylate with a terminal epoxy group (excluding methacrylic acid oxetanyl ester having a four-membered ring epoxy group).

[0061] Comparative Example 2

[0062] Compared with Example 1, the difference in this example is that: in the synthesis of the photocurable resin (A), the unsaturated olefin monomer containing an epoxy group only contains methacrylic acid oxetanyl ester having a four-membered ring epoxy group (excluding glycidyl methacrylate with a terminal epoxy group).

[0063] Comparative Example 3

[0064] Compared with Example 1, the difference in this example is that: the addition amount of the curing accelerator is 0.05 g of 2-methylimidazole.

[0065] Comparative Example 4

[0066] Compared with Example 1, the difference in this example is that no curing accelerator is added.

[0067] III. Performance Test and Evaluation Test Method: The copolymer compositions prepared in the examples and comparative examples were each spin-coated onto a glass substrate. Then, the coated substrate was pre-baked on a hot plate maintained at 110 °C for 90 seconds to form a dry film. Then, an aligner (model name: MA6) that emits light with a wavelength ranging from 200 nm to 450 nm was used, and with a wavelength of 365 nm as a reference, it was exposed at an exposure rate of 200 mJ / cm2 for a certain period of time. Subsequently, the dry cured film was developed with a developer (which is a 0.05 wt% aqueous potassium hydroxide solution) at 23 °C for 60 seconds. Thereafter, the obtained exposed film was heated in a convection oven at 100 °C for 60 minutes to prepare a cured film with a thickness of 1 μm Adhesion: The resin compositions prepared in the examples and comparative examples were each spin-coated onto a glass substrate. Then, the coated substrate was pre-baked on a hot plate maintained at 110 °C for 90 seconds to form a dry film. A cured film was obtained in the same manner as in Example 1, except that a photomask with each pattern of 6 lines in the range of 1 μm to 30 μm separated by 1 μm intervals was applied. Then, a microscope was used to observe the degree of the smallest remaining line pattern in the 1 - 30 μm line pattern on the silicon nitride substrate. During the microscopic observation, the pattern with the lowest CD size remaining after the separation of the line pattern from the mask was evaluated as the development adhesion. The smaller the size of the smallest remaining pattern, the better the development adhesion. Specifically, if the size of the smallest remaining pattern is 4 μm or less, it is marked as high. If it is 5 μm to less than 8 μm, it is marked as medium. If it is 8 μm or greater, it is marked as low Chemical resistance: The cured film with a thickness of 1 (±0.1) μm prepared by the same method as in Example 1 for evaluation was cut into a size of 2 cm × 1 cm to prepare a sample. 10 ml of PGMEA was loaded into a chemical resistance container, the lid was covered, and a water bath was carried out at 90 °C. Then, the sample was immersed and soaked for 10 minutes. After 10 minutes, the sample was taken out, cooled to room temperature, and washed with running water. The thickness of the sample was measured using an SNU device before and after immersion in the solvent. The performance test results are shown in Table 1 below.

[0068] Table 1

[0069] Formulation No. Chemical resistance Adhesiveness (pattern size μm) Adhesiveness (grade judgment) Example 1 Excellent 2μm High Comparative Example 1 Average 8μm Medium Comparative Example 2 Unqualified 10μm Low Comparative Example 3 Average 5μm Medium Comparative Example 4 Unqualified 15μm Low

[0070] Note: Excellent: Thickness change of 10% or less; General: Thickness change greater than 10% to 20%; Unqualified: Thickness change greater than 20%.

[0071] In the present invention, the photocurable resin synthesized from terminal epoxy, quaternary cyclic epoxy groups and comonomers has different ring-opening activation energies due to the differences in the ring tensions of the epoxy groups. When used in combination with an imidazole-derived medium-temperature (50-100 °C) curing accelerator, it promotes the ring-opening addition reaction of epoxy groups under low-temperature conditions (80-120 °C), and then fully crosslinks to form a cured film. The low-temperature cured film formed by the photoresist composition of the present invention has excellent adhesion and chemical resistance.

[0072] Inspired by the ideal embodiments of the present invention described above, through the above description, relevant staff can make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A low temperature negative photoresist composition, characterized in that: The composition comprises the following components by mass percentage: 20-80% of a photocurable resin, 5-60% of a photopolymerizable monomer, 0.1-4.0% of a photopolymerization initiator, 0.1-10% of a curing accelerator and 0.1-0.5% of an additive, the sum of the contents of the components being 100%; and an appropriate amount of solvent; The photocurable resin is a copolymer synthesized by free radical polymerization of unsaturated carboxylic acid, carboxylic anhydride and olefinic unsaturated compound.

2. The low-temperature negative photoresist composition according to claim 1, characterized in that: The photocurable resin is composed of the following monomers in parts by weight: 10-50 parts of unsaturated carboxylic acid monomer methacrylic acid; 50-90 parts of an unsaturated olefin compound having a terminal epoxy group and / or a four-membered ring epoxy group; 10-20 parts of unsaturated olefin compounds with aromatic rings, Under the action of solvent and initiator, polymerization reaction is obtained.

3. The low-temperature negative photoresist composition according to claim 2, characterized in that: The unsaturated carboxylic acid monomer is selected from methacrylic acid, acrylic acid, maleic acid, fumaric acid, aconitic acid and crotonic acid; The unsaturated olefin compound having a terminal epoxy group and / or a four-membered ring epoxy group is composed of glycidyl methacrylate having a terminal epoxy group and oxetane methacrylate having a four-membered ring epoxy group; The unsaturated olefin compound with an aromatic ring is selected from styrene and its derivatives.

4. The low-temperature negative photoresist composition according to claim 2, characterized in that: The molecular weight of the photocurable resin is 2000-40000, preferably 5000-30000.

5. The low-temperature negative photoresist composition according to claim 2, characterized in that: The synthesis method of the photocurable resin is as follows: 25 parts by weight of methacrylic acid, 40 parts by weight of glycidyl methacrylate with a terminal epoxy group, 20 parts by weight of methacrylate oxetane ester with a four-membered ring epoxy group, and 15 parts by weight of styrene are added in sequence to a solvent, and after being fully stirred, 12 parts by weight of an initiator 2,2'-azobis(2,4-dimethylvaleronitrile) are added, and the mixture is heated and kept at about 70±2° C., the reaction is continued for 5 hours, and then cooled to room temperature, and a photocurable resin with a solid content of 32.1% is obtained after filtering and distillation, and a weight-average molecular weight (Mw) of 11205 is obtained.

6. The low-temperature negative photoresist composition according to claim 2, characterized in that: The photopolymerizable monomer is a combination of one or more of pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate modified or unmodified by succinic anhydride.

7. The low-temperature negative photoresist composition according to claim 2, characterized in that: The curing accelerator includes 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole and derivatives thereof.

8. The low-temperature negative photoresist composition according to claim 2, characterized in that: The photopolymerization initiator is a free radical photoinitiator.

9. The low-temperature negative photoresist composition according to claim 8, characterized in that: The free radical photoinitiator includes acetophenone and its derivatives, biimidazole and its derivatives, triazine compounds or oxime compounds.

10. The low-temperature negative photoresist composition according to claim 9, characterized in that: The acetophenone and its derivatives include 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane-1-one, 4,4-bis-(diethylamino)-benzophenone and 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methylpropane-1-one.

11. The low-temperature negative photoresist composition according to claim 9, characterized in that: The triazine compounds include 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine and 2,4-bis(trichloromethyl)-6-(4-methoxyphenylvinyl)-1,3,5-triazine.

12. The low-temperature negative photoresist composition according to claim 9, characterized in that: The biimidazole and its derivatives include 2'-bis(2,3-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole and 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(trialkoxyphenyl)biimidazole.

13. The low-temperature negative photoresist composition according to claim 9, characterized in that: The oxime compounds include: OXE-1: 1-(4-phenylthiophenyl)-octane-1,2-dione-2-benzoic acid oxime ester; OXE-2: 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyl oxime).