Positive photosensitive resin composition, cured film, and pattern processing method

Abstract

The invention provides a positive photosensitive resin composition, a cured film and a pattern processing method, and relates to the technical field of organic EL display. The positive photosensitive resin composition includes (a) an alkali-soluble resin; (b) a photoacid generator; (c) a first thermal crosslinker; (d) a second thermal crosslinking agent; and (e) an organic solvent. Wherein the second thermal cross-linking agent has a general formula represented by a structural formula (1), in the structural formula (1), M is a main structure which contains hydroxyl, phenol or methoxyl and has 6-36 carbon atoms, a linker is an ester group or amide, and the tail end of a hydrophobic group is selected from one or more of vinyl, isopropenyl, methacryloyl, acryloyl, acryloyloxy and methacryloyloxy. After a cured film is formed by the positive photosensitive resin composition, the positive photosensitive resin composition has high bending resistance and high water repellency, the dielectric constant of the cured film is further reduced, high-frequency and high-speed communication can be achieved, and meanwhile the positive photosensitive resin composition can be applied to a flexible organic EL display device comprising a bent part.

Description

Technical Field

[0001] This application relates to the field of organic EL display technology, and more particularly to a positive photosensitive resin composition, a cured film, and a pattern processing method. Background Technology

[0002] Photosensitive polyimide, as an important organic material, has excellent performance and a wide range of applications. It combines the functions of photoresist and dielectric insulating layer, and can pattern PI thin films without the need for other photoresists, thereby saving material costs and shortening the related manufacturing process. With its unique performance and process advantages, photosensitive polyimide has been widely used in high-end fields such as OLED and integrated circuits.

[0003] In recent years, with the development of OLED display devices, such as foldable phones and rollable screens, the demand has been increasing. During the bending process, higher requirements are placed on the physical and chemical properties of the flexible organic EL display devices, particularly on the bendable and / or bent portions. For example, during bending, the bent portion applies bending stress to the planarization layer, pixel segmentation layer, etc. Therefore, in flexible organic EL display devices containing such bent portions, high bending resistance is required for the materials used in the planarization layer and pixel segmentation layer. Existing cured films are insufficient to meet this requirement.

[0004] To achieve high-frequency, high-speed communication, insulators with high impedance are needed to maintain electrical insulation even at high frequencies. Impedance is inversely proportional to the frequency at which the insulator forms and its dielectric constant; therefore, to maintain insulation at high frequencies, the dielectric constant should be as low as possible. However, for typical polyimides, the dielectric properties are not yet sufficiently high to maintain adequate insulation in high-frequency communication. The main reason is that the polar imide groups in polyimide films readily form hydrogen bonds with water molecules, making them relatively susceptible to moisture absorption. The more moisture a polyimide film contains, the higher its dielectric constant.

[0005] Against this background, there is a strong desire to develop a photosensitive resin composition that can be patterned with high sensitivity and has high flexural strength, low water absorption and low dielectric constant. Summary of the Invention

[0006] This application provides a positive photosensitive resin composition, a cured film, and a pattern processing method. After the positive photosensitive resin composition is formed into a cured film, it has high bending resistance and high water repellency, thereby reducing the dielectric constant of the cured film, enabling high-frequency and high-speed communication, and can be applied to flexible organic EL display devices that include curved portions.

[0007] In a first aspect, this application provides a positive photosensitive resin composition, comprising:

[0008] (a) Alkali-soluble resin;

[0009] (b) Photoacid generator;

[0010] (c) First thermal crosslinking agent;

[0011] (d) A second thermal crosslinking agent, the second thermal crosslinking agent having the general formula represented by structural formula (1),

[0012]

[0013] In the structural formula (1), M is a main structure containing hydroxyl, phenol or methoxy groups and having 6 to 36 carbon atoms, the linker is an ester group or an amide, and the end of the hydrophobic group is selected from one or more of vinyl, isopropenyl, methacryloyl, acryloyl, acryloyloxy, and methacryloyloxy groups.

[0014] (e) Organic solvents;

[0015] Based on 100 parts by weight of the alkali-soluble resin, the total amount of the first thermal crosslinking agent and the second thermal crosslinking agent added is 10 to 200 parts by weight.

[0016] In one possible implementation, M is selected from one or more of the following structures:

[0017]

[0018] In one possible implementation, the main structure M is selected from one or more of the following structures:

[0019]

[0020] Where Me is a methyl group.

[0021] In one possible implementation, the hydrophobic group further includes a chain structure, which is an alkyl chain or an alkoxy chain, and the chain structure has 0 to 10 carbon atoms. The chain structure is connected to the linker through oxygen atoms, or the chain structure is directly connected to the linker.

[0022] In one possible implementation, the hydrophobic group is selected from one or more of the following structures:

[0023]

[0024] Where n = 0 to 10, m = 1 to 5.

[0025] In one possible implementation, the second thermal crosslinking agent is selected from one or more of the following compounds:

[0026]

[0027]

[0028] In one possible implementation, the second thermal crosslinking agent is selected from one or more of the following compounds:

[0029] In one possible implementation, based on 100 parts by weight of the alkali-soluble resin, the amount of the first thermal crosslinking agent added is 5 to 40 parts by weight, and the amount of the second thermal crosslinking agent added is 15 to 40 parts by weight.

[0030] In a second aspect, this application provides a cured film, comprising: a film obtained by curing a positive photosensitive resin composition as described in any embodiment of the first aspect.

[0031] Thirdly, this application provides a method for patterning a cured film, comprising the following steps:

[0032] i) The positive photosensitive resin composition described in any one embodiment of the first aspect is coated on a substrate and dried at 40 to 120°C for 1 to 10 minutes to form a positive photosensitive resin composition film.

[0033] ii) Expose the film under a mask;

[0034] iii) Remove the exposed portions of the film using an alkaline developer, develop and clean it;

[0035] iiii) The developed film is cured and dried at 100-400°C to obtain a cured film containing the desired pattern.

[0036] In the above technical solution, a second thermal crosslinking agent with flexible hydrophobic groups is added to the positive photosensitive resin composition. This agent improves the bending resistance and water repellency of the cured film through its unique flexible hydrophobic groups, thereby reducing the dielectric constant. The cured film provided in this application enables high-frequency, high-speed communication and can be applied to flexible organic EL display devices containing curved portions, such as foldable phones and rollable screens. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0038] It should be understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0039] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] It should be noted that the following embodiments are examples of this application and are used only to illustrate this application, and are not intended to limit this application. Other combinations and various modifications within the scope of this application are possible without departing from the spirit or scope of this application.

[0041] The following provides a detailed description of the positive photosensitive resin composition, cured film, and pattern processing method provided in this application.

[0042] The positive photosensitive resin composition of this application includes (a) an alkali-soluble resin; (b) a photoacid generator; (c) a first thermal crosslinking agent; (d) a second thermal crosslinking agent; and (e) an organic solvent.

[0043] Among them, (d) the second thermal crosslinking agent has the general formula represented by structural formula (1),

[0044]

[0045] In structural formula (1), M is a main structure containing hydroxyl, phenol or methoxy groups and having 6 to 36 carbon atoms, the linker is an ester group or an amide, and the end of the hydrophobic group is selected from one or more of vinyl, isopropenyl, methacryloyl, acryloyl, acryloyloxy, and methacryloyloxy groups.

[0046] This application introduces a (d) second thermal crosslinking agent with flexible hydrophobic groups into a positive photosensitive resin composition. This results in a cured film with high flexural strength and high water repellency, thereby reducing the dielectric constant of the cured film. The cured film provided by this application maintains electrical insulation at high frequencies, enabling high-frequency, high-speed communication. Simultaneously, it exhibits excellent flexural strength, making it suitable for use in flexible organic EL display devices containing curved sections, such as foldable phones and rollable screens.

[0047] Since both (c) the first thermal crosslinking agent and (d) the second thermal crosslinking agent can crosslink with (a) the alkali-soluble resin via hydroxyl, phenol, or methoxy groups, there may be a competitive reaction between them. To avoid this, based on 100 parts by weight of (a) the alkali-soluble resin, the total amount of (c) the first thermal crosslinking agent and (d) the second thermal crosslinking agent is 10 to 200 parts by weight. Preferably, the total amount of (c) the first thermal crosslinking agent and (d) the second thermal crosslinking agent is 20 to 100 parts by weight. From the perspective of improving bending resistance, dielectric constant, imaging capability, and chemical resistance, it is further preferred that the total amount of (c) the first thermal crosslinking agent and (d) the second thermal crosslinking agent is 20 to 80 parts by weight.

[0048] In this application, (d) the main structure M of the second thermal crosslinking agent is selected from one or more of the following structures:

[0049]

[0050] Since the developed pattern needs to be cured at 250°C in the subsequent curing process, the second thermal crosslinking agent (d) needs to have a certain degree of heat resistance. From the perspective of improving heat resistance, the main structure M of the second thermal crosslinking agent (d) is preferably a structure containing benzene rings, and more preferably a structure containing two or more benzene rings. Considering both developability and optical transmittance, the main structure M of the second thermal crosslinking agent (d) is further preferably a structure containing two benzene rings. Preferably, the main structure M of the second thermal crosslinking agent (d) is selected from one or more of the following structures:

[0051]

[0052] Where Me is a methyl group.

[0053] In this application, the hydrophobic group also includes a chain structure, which is an alkyl chain or an alkoxy chain, and the chain structure has 0 to 10 carbon atoms. The chain structure is connected to the linker through oxygen atoms, or the chain structure is directly connected to the linker.

[0054] The presence of long-chain hydrophobic groups in the second thermal crosslinking agent (d) effectively increases the bending resistance of the cured film. As the chain length of the hydrophobic groups in the second thermal crosslinking agent (d) increases, the bending resistance of the resulting cured film also increases. However, the solubility of the second thermal crosslinking agent (d) in the solvent decreases. This is presumably because the increased chain length leads to a decrease in polarity, thus affecting its solubility in the solvent. From a solubility perspective, the number of carbon atoms in the chain structure of the hydrophobic groups in the second thermal crosslinking agent (d) is 0–10, more preferably 4–6.

[0055] The hydrophobic group is selected from one or more of the following structures:

[0056]

[0057] Where n = 0 to 10, m = 1 to 5.

[0058] Specifically (d) the second thermal crosslinking agent is selected from one or more of the following compounds:

[0059]

[0060]

[0061] Introducing trifluoromethyl groups into the second thermal crosslinking agent (d) can further improve the hydrophobicity of the resulting cured film, thereby reducing the dielectric constant. Therefore, the second thermal crosslinking agent (d) is preferably one or more of the following compounds:

[0062]

[0063] Considering the solubility of the second thermal crosslinking agent in the developer, the bending resistance, dielectric constant, imaging capability, and chemical resistance of the obtained cured film, the amount of the second thermal crosslinking agent added is 5 to 40 parts by weight, preferably 15 to 40 parts by weight, based on 100 parts by weight of the alkali-soluble resin added in (a).

[0064] The positive photosensitive resin composition provided in this application includes (a) an alkali-soluble resin; (b) a photoacid-generating agent; (c) a first thermal crosslinking agent; (d) a second thermal crosslinking agent; and (e) an organic solvent. Each component is described below in turn.

[0065] <(a) Alkali-soluble resin>

[0066] (a) The main chain structure of the alkali-soluble resin contains structural units with structural formula (a1) and structural units with structural formula (a2);

[0067]

[0068] Wherein, X and Y are reactive residues of dianhydrides, and P and Q are reactive residues of diamines; at least one of the monomers corresponding to X, Y, P, and Q contains a phenolic hydroxyl group; R1 and R2 are each independently H or an organic group having 1 to 20 carbon atoms.

[0069] X and Y are each independently selected from one or more of the following structures:

[0070]

[0071] And / or, P and Q are each independently selected from one or more of the following structures:

[0072]

[0073] In order to ensure that (a) the alkali-soluble resin has appropriate solubility in alkaline developer and that (a) the alkali-soluble resin has good heat resistance and elongation after heat treatment, the repeating number of aromatic ring structural units is preferably in the range of 1 to 100, and more preferably 2 to 50.

[0074] (a) The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the alkali-soluble resin were determined using gel permeation chromatography (GPC), light scattering, small-angle X-ray scattering, etc., in the form of polystyrene equivalents. The weight-average molecular weight (Mw) determined by gel permeation chromatography (GPC) was 1000–100000. To obtain moderate solubility and excellent film properties in alkaline developing solutions, a value of 3000–50000 (Mw) was preferred, and more preferably 10000–30000 (Mw).

[0075] In addition, to better adjust the molecular weight of (a) alkali-soluble resins, a certain amount of end-capping agent can be added during polymerization. Specific examples include, but are not limited to, one or more combinations of the following example compounds:

[0076] Monofunctional aromatic amines: 3-aminophenol, 2-aminophenol, 4-aminophenol, 3-aminobenzoic acid, 3-amino-o-methylbenzoic acid, 3-amino-m-methylbenzoic acid, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 1-amino-8-hydroxynaphthalene, 1-amino-7-hydroxynaphthalene, 1-amino-6-hydroxynaphthalene, 1-amino-5-hydroxynaphthalene, 1-amino-4-hydroxynaphthalene, 1-amino-3-hydroxynaphthalene, 1-amino-2-hydroxynaphthalene, 1-carboxy-8-aminonaphthalene, 1-carboxy-7-aminonaphthalene, 1-carboxy-6-aminonaphthalene, 1-carboxy-5-aminonaphthalene, 1-carboxy-4-aminonaphthalene, 1-carboxy-3-aminonaphthalene, 1-carboxy-2-aminonaphthalene, 3-amino-4,6-dihydroxypyrimidine, 5-amino-8-hydroxyquinoline, 4-amino-8-hydroxyquinoline.

[0077] Monofunctional aromatic anhydrides: maleic anhydride, phthalic anhydride, cyclohexanedicarboxylic anhydride, cyclohexanepentanedicarboxylic anhydride, etc.

[0078] Monofunctional aromatic acids: benzoic acid, o-methylbenzoic acid, m-methylbenzoic acid, p-methylbenzoic acid, 2-carboxyphenol, 3-carboxyphenol, 4-carboxyphenol, 2-carboxybenzylthiophenol, 3-carboxybenzylthiophenol, 4-carboxybenzylthiophenol, carboxynaphthalene, 2-hydroxy-naphthoic acid, 3-hydroxy-naphthoic acid, 4-hydroxy-naphthoic acid, 5-hydroxy-naphthoic acid, 6-hydroxy-naphthoic acid, 7-hydroxy-naphthoic acid, 8-hydroxy-naphthoic acid, 9-hydroxy-naphthoic acid.

[0079] The aforementioned capping agent is added in proportions of 0.005 to 0.5, more specifically 0.01 to 0.4, of the total molar amount of all added diamine compounds and tetracarboxylic dianhydrides; within the above range, a resin composition having a suitable solution viscosity and excellent film properties can be obtained.

[0080] <(b) Photoacid generator>

[0081] The positive photosensitive resin composition provided in this application also uses (b) a photoacid-generating agent, which can be listed as quinone diazide compounds (naphthoquinone diazidesulfonate compounds), sulfonium salts, phosphonium salts, diazonium salts, iodonium salts, etc., which can be used alone or in combination of two or more. These quinone diazide compounds can be synthesized by esterification reaction of phenolic hydroxyl compounds with quinone diazidesulfonyl chloride.

[0082] In this application, the quinone diazide compounds are preferably compounds in which a 5-naphthoquinone diazidesulfonyl group or a 4-naphthoquinone diazidesulfonyl group is bonded to a compound having a phenolic hydroxyl group. Specific examples of phenolic hydroxyl compounds are shown in the following structures:

[0083]

[0084] As a quinone diazide compound, the molecular structure preferably has one or more combinations of naphthoquinone diazide sulfonate structures. Specific examples include PAC-1 to PAC-20. (b) Photoacid-generating agents can be used in one or more combinations.

[0085]

[0086] Based on 100 parts by weight of (a) alkali-soluble resin, the amount of (b) photoacid-generating agent added is 5 to 40 parts by weight, preferably 10 to 40 parts by weight.

[0087] <(c) First thermal crosslinking agent>

[0088] (c) The first thermal crosslinking agent improves the chemical resistance of the cured film by reacting with (a) alkali-soluble resin through heating. (c) The first thermal crosslinking agent is selected from one or more of epoxy compounds, alkoxy compounds, and hydroxymethyl compounds.

[0089] The epoxy compounds are preferably compounds containing two or more epoxy groups within a single molecule. Examples include bisphenol A type epoxy resins, bisphenol A type oxetane resins, bisphenol F type epoxy resins, bisphenol F type oxetane resins, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polymethyl (glycidyloxypropyl)siloxane, and other epoxy-containing organosilicon compounds, but are not limited to these. Specific examples include Dai Nippon Ink Chemical Industry's EPICLON and EXA series products, Yuka Shell Epoxy Co., Ltd.'s Epikote series of bisphenol A type epoxy compounds, and ADEKA's EP series, etc.

[0090] Alkoxy compounds and hydroxymethyl compounds are preferably compounds containing two or more functional groups in a molecule, with a number of 2 to 8. Examples include the trade names DML, TriML, DMOM, HMOM, TMOM, etc. from Honshu Chemical, and the MX and MW series from Sanwa Chemical.

[0091] Considering the solubility of the first thermal crosslinking agent in the developer, the bending resistance, dielectric constant, imaging capability, and chemical resistance of the obtained cured film, the amount of the first thermal crosslinking agent added is 5 to 60 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the alkali-soluble resin added in (a).

[0092] <(d) Second thermal crosslinking agent>

[0093] (d) The second thermal crosslinking agent is as described above.

[0094] <(e) Organic solvents>

[0095] Considering the solubility of the polyimide precursor resin, polar solvents are preferred. (e) Examples of organic solvents include: N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, 3-methoxybutanol, γ-butyrolactone, 3-methoxybutanol acetate, δ-valerolactone, γ-valerolactone, cyclohexanone, cyclopentanone, propylene glycol monomethyl ether acetate, ethyl lactate, and 1,3-dimethyl-2-imidazolinone. Among these, γ-butyrolactone, propylene glycol monomethyl ether acetate, 3-methoxybutanol, 3-methoxybutanol acetate, and ethyl lactate are preferred; they can be used alone or in combination of two or more. The content of (e) organic solvent in the positive photosensitive resin composition of this application is not particularly limited, but is preferably 50 to 2000 parts by mass relative to 100 parts by mass of (a) alkali-soluble resin component, more preferably 200 to 2000 parts by mass, and even more preferably 300 to 2000 parts by mass.

[0096] <Other Additives>

[0097] Furthermore, in addition to the above-mentioned components, the positive photosensitive resin composition of this application may also contain, as needed, components such as organosilane compounds and surfactants.

[0098] Organosilane compounds are mainly used to improve the adhesion between the cured film and silicon or glass substrates. Examples include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, γ-acryloyloxypropyltrimethoxysilane, 3-ureapropyltriethoxysilane, 3-ureapropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-(triethoxysilyl)propylsuccinic anhydride, phenyltriethoxysilane, phenyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 1-isocyanate-methyltrimethylsilane, 1-isocyanate-methyltriethylsilane, 1- Isocyanate-based methyltripropylsilane, 1-isocyanate-based methyltributylsilane, 1-isocyanate-based methyltrimethoxysilane, 1-isocyanate-based methyldimethoxymethylsilane, 1-isocyanate-based methylmethoxydimethylsilane, 1-isocyanate-based methyltriethoxysilane, 1-isocyanate-based methyltripropoxysilane, 1-isocyanate-based methyltributoxysilane, 1-isocyanate-based methyldiethoxyethylsilane, 3-isocyanate-based propyltrimethylsilane, 3-isocyanate-based propyltriethylsilane, 3-isocyanate-based propyltrimethoxysilane, 3-isocyanate-based propyldimethoxymethylsilane, 3-isocyanate-based propylmethoxydimethylsilane, 3-isocyanate-based propyltriethoxysilane, 3-isocyanate-based propyldiethoxyethylsilane, etc.

[0099] In this application, the surfactants selected are fluorinated surfactants, silicone surfactants, acrylate surfactants, esters, and ketones. In the embodiments of this application, ethyl lactate, ethyl acetate, methyl ethyl ketone, and cyclohexanone are preferred. The amount of surfactant added is 0.0003 to 0.05 of the total polymer mass.

[0100] <Cured film>

[0101] The cured film involved in this application is obtained by curing the positive photosensitive resin composition of this application. There is no particular limitation on the thickness of the cured film, but it is preferably 0.1 μm to 10.0 μm. More preferably, it is 1 μm to 5 μm. By making the film thickness more than 1 μm, an insulating layer with better insulation can be obtained, and by making the film thickness less than 5 μm, the pore resolution of the cured film can be higher, thereby obtaining a finer pattern.

[0102] <Pattern Processing Methods>

[0103] The following is a detailed description of a pattern processing method for forming resin patterns using the positive photosensitive resin composition of this application.

[0104] The photosensitive resin composition of this application is uniformly coated onto a substrate (the substrate includes silicon wafers, TFT substrates, organic EL elements, substrates with a metal coating on the surface by ion sputtering or electroplating, etc.) by methods such as dip coating, spin coating, roll coating, slot coating, spraying, and microgravure coating. The coated substrate is then pre-baked at 50 to 150°C for 30 seconds to 60 minutes using a heating device such as a hot plate or oven.

[0105] Exposure equipment (such as a parallel light mask aligner, stepper exposure machine, etc.) is used to expose the pre-baked substrate with the coating film. The exposure dose is 5 to 5000 mj / cm2. There are no specific restrictions on the exposure light source and wavelength. Ultraviolet light such as g, i, and h can be used, or lasers such as KrF (248nm) and ArF (193nm) can be used.

[0106] After exposure, the exposed portions on the film are removed using a developer. Preferably, the developer is an aqueous solution of an alkaline compound such as tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, dimethylamine, dimethylaminoethanol, cyclohexylamine, or ethylenediamine. Alternatively, one or more combinations of organic solvents such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, methanol, ethanol, isopropanol, ethyl lactate, cyclopentanone, cyclohexanone, or acetone can be added to these alkaline aqueous solutions.

[0107] The development method is one of spray development, immersion development, or ultrasonic immersion development; the development time, development temperature, and development steps are all determined by removing the exposed portions. After development, the film is preferably rinsed with water, and more preferably with an aqueous solution of alcohols or esters such as ethanol, isopropanol, or ethyl lactate. After rinsing, the film can be dried by heating in the range of 60–200°C for 1–60 minutes.

[0108] The positive photosensitive resin composition of this application, after exposure, development, and rinsing, undergoes a staged programmed temperature rise / isothermal heat treatment within the range of 100–400°C to cure and form a cured film. Examples of the temperature rise / isothermal heat treatment methods include: starting from room temperature at a temperature rise rate of 5°C / min, then isothermal heat treatment at 120°C and 180°C for 30 min respectively, followed by temperature rise to 250°C for 2 h; or, rising from room temperature to 250°C within 2 h at a temperature rise rate of 5°C / min, followed by isothermal heat treatment at 250°C for 2 h. The temperature rise / isothermal heat treatment is carried out under normal pressure, nitrogen, or vacuum; curing yields a cured film containing an ideal pattern.

[0109] The film obtained by the photosensitive resin in this application through the above process exhibits excellent film properties, such as heat resistance, chemical resistance, bending resistance and low dielectric constant, and can therefore be used in semiconductor TFTs, insulating layers / planarization layers of organic electroluminescent elements, etc.

[0110] Example

[0111] The present application will be described below with examples, but the present application is not limited to these examples. First, the evaluation methods in each example and comparative example will be described.

[0112] <Dielectric Constant Evaluation>

[0113] By spin coating, the positive photosensitive resin composition obtained in the following examples and comparative examples is coated onto an ITO glass substrate at an arbitrary rotation speed to obtain a photosensitive resin film. As a step to dry the photosensitive resin film, it is pre-baked on a heating plate at 120°C for 2 minutes to obtain a dried photosensitive resin film. Without performing an exposure and development process, the substrate with the photosensitive resin film attached to its entire surface is then cured (heat treatment) for 60 minutes in a nitrogen atmosphere at 250°C to obtain a cured film with a thickness of 4.0 μm. An epitos ellipsometer (manufactured by Yiguang Technology) is used to measure the film thickness at 9 points, and the film thickness and uniformity are recorded. The film thickness uniformity is required to be within 1%. The cured substrate with the photosensitive resin film is then coated using a dual-target magnetron sputtering instrument (manufactured by Shenyang Kejing VTC-600-2HD). The dielectric constant of the substrate with the photosensitive resin film attached is measured at a frequency of 1 kHz at 4 locations in the surface using an LCR meter E4980A (manufactured by Agilent Technologies). The average value is rounded to the second decimal place to obtain the value up to the first decimal place.

[0114] <Bending Resistance Evaluation>

[0115] The positive photosensitive resin compositions obtained in the examples and comparative examples described below were coated onto a polyimide film substrate using a spin coating method at an arbitrary rotation speed to obtain a photosensitive resin film. As a drying step, the photosensitive resin film was pre-baked on a heated plate at 120°C for 2 minutes to obtain a dried photosensitive resin film. Without an exposure step, the film was then spray-developed for 90 seconds using an automatic developing apparatus (AD-2000 manufactured by Takizawa Sangyo Co., Ltd.) with a 2.38% by mass tetramethylammonium hydroxide aqueous solution, followed by a 30-second rinse with pure water. Using an inert oven (CLH-21CD-S manufactured by Koyo Thermo Systems, Inc., hereinafter referred to as the inert oven), a substrate with a developed photosensitive resin film adhered to its entire surface was cured (heat treatment) for 60 minutes in an oven at 250°C under a nitrogen atmosphere to obtain a cured film with a thickness of 2.0 μm. Ten sheets, including the cured film, were then cut into pieces measuring 50 mm x 10 mm. The cut cured films were then stored in air at 100°C for 500 hours. Next, the film was bent 180° along a 25 mm line and held in this position for 30 seconds. After 30 seconds, the bent cured film was opened, and the bending portion along the 25 mm line on the surface of the cured material on the polyimide film substrate was observed using an FPD inspection microscope (MX-61L; manufactured by Olympus, Inc.) to evaluate the changes in the appearance of the cured surface. The bending test was conducted within a radius of curvature of 0.05 mm to 1.0 mm. The minimum radius of curvature was recorded when no peeling of the cured material from the polyimide film substrate or cracks appeared on the surface of the cured material. The smaller the minimum radius of curvature, the stronger the bending resistance of the cured film.

[0116] <Imaging Capability Evaluation>

[0117] For the cured film of the photosensitive resin composition formed by development, the surface is visually observed for the stickiness of the unexposed areas and the residue in the exposed areas. A film with no pattern defects is judged as excellent; a film with a small amount of stickiness in the unexposed areas or a small amount of residue in the exposed areas is judged as fair; and a film with a large amount of stickiness in the unexposed areas or a large amount of residue in the exposed areas is judged as poor.

[0118] <Chemical Resistance Testing Evaluation>

[0119] The cured film was heat-treated at 300°C for 250 seconds, and a 10x10 checkerboard pattern was created on the cured film at 1m intervals using a cutter. Then, the film was immersed in an ITO etching solution (hydrochloric acid / potassium chloride / water = 5 / 7 / 98 (weight ratio)) at 50°C for 300 seconds. Afterward, transparent tape (cellophane tape) was applied to the checkerboard pattern, and the residual state of the checkerboard pattern upon peeling was observed. The retention rate of the checkerboard pattern was defined as follows: Zero: 100% peeling; Poor: 40% residue; Very poor: 40% to less than 60% residue; Average: 60% to less than 80% residue; Good: 80% to less than 95% residue; Excellent: 95% or more residue.

[0120] The embodiments of this application are described in detail below. First, the abbreviations corresponding to some of the compounds involved in the embodiments are explained.

[0121] Diamine compound 1:

[0122] Diamine compound 2:

[0123] ODPA: 3,3',4,4'-Diphenyl ether tetracarboxylic dianhydride

[0124] NMP: N-methylpyrrolidone

[0125] mPA: 3-Aminophenol

[0126] DMF-DMA: N,N-dimethylformamide dimethyl acetal

[0127] 6-FAP: 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane

[0128] THF: Tetrahydrofuran

[0129] NaH: Sodium hydride

[0130] PAC-9:

[0131] Synthesis Example 1 (Synthesis of Alkali-Soluble Resin A1)

[0132] Under a dry nitrogen stream, 62.0 g (0.20 mol) of ODPA was dissolved in 500 g of NMP. 140.6 g (0.16 mol) of diamine compound 1 and 200 g of NMP were then added together, and the mixture was reacted at 20 °C for 1 hour, followed by a reaction at 50 °C for 2 hours. Next, 8.7 g (0.08 mol) of mPA and 50 g of NMP were added together, and the mixture was reacted at 50 °C for 2 hours. Then, over 10 minutes, a solution prepared by diluting 47.7 g (0.40 mol) of DMF-DMA with 100 g of NMP was added dropwise. After the addition, the mixture was stirred at 50 °C for 3 hours. After stirring, the solution was cooled to room temperature and precipitated in 2L of ethanol:water = 2:1 (volume ratio) solvent to obtain a white precipitate. The precipitate was filtered, and the filter cake was washed several times with ethanol:water = 2:1 (volume ratio) and then dried under vacuum at 50℃ for 72h to obtain alkali-soluble resin A1 powder.

[0133] Synthesis Example 2 (Synthesis of Alkali-Soluble Resin A2)

[0134] Under a dry nitrogen stream, 62.0 g (0.20 mol) of ODPA was dissolved in 500 g of NMP. 96.7 g (0.16 mol) of diamine compound 2 and 200 g of NMP were then added together, and the mixture was reacted at 20 °C for 1 hour, followed by a reaction at 50 °C for 2 hours. Next, 8.7 g (0.08 mol) of mPA and 50 g of NMP were added together, and the mixture was reacted at 50 °C for 2 hours. Then, over 10 minutes, a solution prepared by diluting 47.7 g (0.40 mol) of DMF-DMA with 100 g of NMP was added dropwise. After the addition, the mixture was stirred at 50 °C for 3 hours. After stirring, the solution was cooled to room temperature and precipitated in 2L of ethanol:water = 2:1 (volume ratio) to obtain a white precipitate. The precipitate was filtered, and the filter cake was washed several times with ethanol:water = 2:1 (volume ratio) and then dried under vacuum at 50℃ for 72h to obtain alkali-soluble resin A2 powder.

[0135] Synthesis Example 3 (Synthesis of Second Thermal Crosslinking Agent D1)

[0136] 0.6 mol of 5-(methacryloyloxy)valerate was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 6-FAP was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution containing 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D1.

[0137]

[0138] Synthesis Example 4 (Synthesis of Second Thermal Crosslinking Agent D2)

[0139] 0.6 mol of 5-(methacryloyloxy)valerate was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 2,2-bis(4-hydroxy-3-aminophenyl)propane was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution containing 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D2.

[0140]

[0141] Synthesis Example 5 (Synthesis of Second Thermal Crosslinking Agent D3)

[0142] 0.6 mol of 5-(methacryloyloxy)valerate was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 4,4'-oxybis(2-aminophenol) was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution containing 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D3.

[0143]

[0144] Synthesis Example 6 (Synthesis of Second Thermal Crosslinking Agent D4)

[0145] 0.6 mol of 5-(methacryloyloxy)valerate was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of bis(3-amino-4-hydroxyphenyl) ketone was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution containing 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D4.

[0146]

[0147] Synthesis Example 7 (Synthesis of Second Thermal Crosslinking Agent D5)

[0148] 0.6 mol of 5-(methacryloyloxy)valerate was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The filtrate was dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 3,3'-diamino-4,4'-biphenyl glycol was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution containing 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D5.

[0149]

[0150] Synthesis Example 8 (Synthesis of Second Thermal Crosslinking Agent D6)

[0151] 0.6 mol of 2,2-bis(3-carboxy-4-hydroxyphenyl)-hexafluoropropane was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 2-(2-(2-hydroxyethoxy)ethoxy)ethyl methacrylate was dissolved in 350 mL of THF. The system temperature was lowered to 0–5 °C in an ice-water bath. 0.12 mol of NaH was added in batches to react for 2 h. After the reaction was carried out, the system was restored to room temperature and reacted for another 2 h. The system was then restored to 0–5 °C in an ice-water bath. 0.05 mol of the obtained acyl chloride was dissolved in 100 mL of THF. The THF solution of the obtained acyl chloride was slowly added dropwise to the system. After the addition was completed, the system was reacted at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D6.

[0152]

[0153] Synthesis Example 9 (Synthesis of Second Thermal Crosslinking Agent D7)

[0154] 0.6 mol of 2,2-bis(3-carboxy-4-hydroxyphenyl)-hexafluoropropane was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain the corresponding acyl chloride. 0.11 mol of 6-hepten-1-ol was dissolved in 350 mL of THF. The system temperature was lowered to 0–5 °C in an ice-water bath. 0.12 mol of NaH was added in batches to the system for reaction. After reacting for 2 h, the system was restored to room temperature and reacted for another 2 h. The system was then restored to 0–5 °C in an ice-water bath. 0.05 mol of the obtained acyl chloride was dissolved in 100 mL of THF. The THF solution of the obtained acyl chloride was slowly added dropwise to the system. After the addition was complete, the system was reacted at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D7.

[0155]

[0156] Synthesis Example 10 (Synthesis of Second Thermal Crosslinking Agent D8)

[0157] 0.11 mol of 2,2-bis(4-hydroxy-3-aminophenyl)propane was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution of 0.05 mol of methacryloyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D8.

[0158]

[0159] Synthesis Example 11 (Synthesis of Second Thermal Crosslinking Agent D9)

[0160] 0.6 mol of 2,2-bis(3-carboxy-4-hydroxyphenyl)-hexafluoropropane was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 14-hydroxy-3,6,9,12-tetraoxatetradecane methacrylate was dissolved in 350 mL of THF. The system temperature was lowered to 0–5 °C in an ice-water bath. 0.12 mol of NaH was added in batches to the system for reaction. After reacting for 2 h, the system was restored to room temperature and reacted for another 2 h. The system was then restored to 0–5 °C in an ice-water bath. 0.05 mol of the obtained acyl chloride was dissolved in 100 mL of THF. The THF solution of the obtained acyl chloride was slowly added dropwise to the system. After the addition was complete, the system was reacted at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D9.

[0161]

[0162] Synthesis Example 12 (Synthesis of Second Thermal Crosslinking Agent D10)

[0163] 0.6 mol of 5-(methacryloyloxy)valerate was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The filtrate was dried under reduced pressure to obtain the corresponding acyl chloride. 0.11 mol of diamine compound 1 was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution of 0.05 mol of the obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was completed, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D10.

[0164]

[0165] Synthesis Example 13 (Synthesis of Second Thermal Crosslinking Agent D11)

[0166] 0.6 mol of 5-(methacryloyloxy)valerate was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The filtrate was dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 4,6-diamino-1,3-cyclohexanediol was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution containing 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D11.

[0167]

[0168] Synthesis Example 14 (Synthesis of Second Thermal Crosslinking Agent D12)

[0169] 0.6 mol of 14-methacryloyloxytetradecyl acid was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain its corresponding acyl chloride. 0.11 mol of 6-FAP was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution containing 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D12.

[0170]

[0171] Synthesis Example 15 (Synthesis of Second Thermal Crosslinking Agent D13)

[0172] 20 mL of concentrated sulfuric acid (98%) was added to a solution containing 39.6 g (0.2 mol) of n-butanol (110 mL) and benzene (30 mL) and stirred. The mixture was heated under reflux using a water separator and stirred for 8 hours. Excess n-butanol and benzene were then distilled off, and the residue was poured into ice water (150 mL) and neutralized to pH 7–8 with saturated sodium carbonate solution. The aqueous solution was extracted with ethyl acetate (3 × 200 mL). The combined extracts were dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to remove excess ethyl acetate, and the resulting oil was purified by column chromatography to obtain the second thermal crosslinking agent D13 represented by the following formula.

[0173]

[0174] Synthesis Example 16 (Synthesis of Second Thermal Crosslinking Agent D14)

[0175] 0.6 mol of hexanoic acid was stirred in 110 mL of thionyl chloride at room temperature for 2 h. The system was then dried under reduced pressure to obtain hexanoyl chloride. 0.11 mol of 6-FAP was dissolved in 200 mL of acetone and 0.3 mol of propylene oxide. A solution of 0.05 mol of the previously obtained acyl chloride dissolved in 100 mL of acetone was added dropwise. After the addition was completed, the reaction was carried out at room temperature for 4 h. The system was then concentrated under reduced pressure at 35 °C. The concentrated sample was purified by column chromatography to obtain the second thermal crosslinking agent D14.

[0176]

[0177] Example 1

[0178] This embodiment provides a positive photosensitive resin composition, which is prepared by taking 10g of alkali-soluble resin A1, adding 1.5g of photoacid generator PAC-9, 0.5g of first thermal crosslinking agent HMOM-TPHAP (manufactured by Honshu Chemical Industry Co., Ltd.), 0.5g of second thermal crosslinking agent D1, and 10g of solvent γ-butyrolactone to prepare a varnish.

[0179] A varnish was applied to a silicon substrate and dried at 120°C for 2 minutes to form a film. The film was then exposed using a small photolithography developing apparatus (AC3000; manufactured by Takizawa Sangyo Co., Ltd.). After exposure, the film was developed for 70 seconds using a 2.38% (w / w) tetramethylammonium hydroxide aqueous solution, followed by rinsing with water for 30 seconds. After development and rinsing, the film was thermally cured at 250°C using a high-temperature inert gas oven (INH-9CD-S; manufactured by KoyoThermo Systems Co., Ltd.) to produce a cured film with a thickness of approximately 2 μm. The thermal curing conditions were 250°C for 60 minutes under a nitrogen atmosphere. The cured film was then evaluated.

[0180] Examples 2-15 & Comparative Examples 1-5

[0181] Examples 2-15 and Comparative Examples 1-5 each provide a positive photosensitive resin composition. The preparation method is largely the same as that in Example 1, except for the selection and ratio of the alkali-soluble resin, the first thermal crosslinking agent, and the second thermal crosslinking agent. Specific formulations are shown in Table 1. The photosensitive resin compositions prepared in Examples 1-15 and Comparative Examples 1-5 were evaluated for their imaging ability, dielectric constant, bending resistance, adhesion, and chemical resistance. The results are shown in Table 1.

[0182] Table 1. Formulations and evaluation results of Examples 1-15 and Comparative Examples 1-5

[0183]

[0184]

[0185] Table 1 provides the components of the positive photosensitive resin compositions of Examples 1-15 and Comparative Examples 1-5. By comparing Examples 1-5 and Comparative Example 1, it can be found that when the second thermal crosslinking agent is not added, the dielectric constant of the positive photosensitive resin composition is high and the bending resistance is poor. When the second thermal crosslinking agent is added, the dielectric constant of the positive photosensitive resin composition is lower than 3.0 and the bending resistance is less than 0.15.

[0186] By comparing Examples 1-5 and Comparative Example 2, it can be found that when the amount of the first thermal crosslinking agent and the second thermal crosslinking agent is appropriate, the dielectric constant, bending resistance, imaging ability and chemical resistance of the positive photosensitive resin composition are all good, that is, the positive photosensitive resin composition has good comprehensive performance; when the amount of the first thermal crosslinking agent and the second thermal crosslinking agent is too large, the imaging ability of the positive photosensitive resin composition decreases.

[0187] Comparative examples 1-5 show that, based on 100 parts by weight of alkali-soluble resin, the overall performance of the positive photosensitive resin composition is better when the total amount of the first thermal crosslinking agent and the second thermal crosslinking agent is 20-100 parts by weight, and the overall performance of the positive photosensitive resin composition is even better when the total amount of the first thermal crosslinking agent and the second thermal crosslinking agent is 80 parts by weight.

[0188] As shown in Examples 3 and 6, when the main structure M of the second thermal crosslinking agent contains fluorine, the dielectric constant of the second thermal crosslinking agent is lower, and its performance is better. As shown in Examples 6-15, when the number of carbon atoms in the chain structure of the second thermal crosslinking agent is 4-6, the positive photosensitive resin composition has better bending resistance and imaging ability; compared with Comparative Example 3, when the number of carbon atoms in the chain structure of the second thermal crosslinking agent is too high, the bending resistance of the positive photosensitive resin composition decreases, and its imaging ability and chemical resistance are poor. As shown in Examples 6-15 and Comparative Examples 4-5, when the added second thermal crosslinking agent has no hydrophobic groups, the dielectric constant of the positive photosensitive resin composition is higher, and its imaging ability and chemical resistance are also poor.

[0189] Of the above embodiments, Embodiments 3, 10, and 11 are the most preferred, and the positive photosensitive resin composition exhibits the best overall performance.

[0190] Although the embodiments of this application have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this application. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this application is not limited to the specific details and embodiments shown and described herein.

Claims

1. A positive photosensitive resin composition, characterized in that, include: (a) Alkali-soluble resin; (b) Photoacid generator; (c) First thermal crosslinking agent; (d) A second thermal crosslinking agent, the second thermal crosslinking agent having the general formula represented by structural formula (1), In the structural formula (1), M is a main structure containing hydroxyl, phenol or methoxy groups and having 6 to 36 carbon atoms, the linker is an ester group or an amide, and the end of the hydrophobic group is selected from one or more of vinyl, isopropenyl, methacryloyl, acryloyl, acryloyloxy, and methacryloyloxy groups. (e) Organic solvents; Based on 100 parts by weight of the alkali-soluble resin, the total amount of the first thermal crosslinking agent and the second thermal crosslinking agent added is 10 to 200 parts by weight.

2. The positive photosensitive resin composition according to claim 1, characterized in that, The M is selected from one or more of the following structures:

3. The positive photosensitive resin composition according to claim 2, characterized in that, The main structure M is selected from one or more of the following structures: Where Me stands for methyl group.

4. The positive photosensitive resin composition according to claim 1, characterized in that, The hydrophobic group further includes a chain structure, which is an alkyl chain or an alkoxy chain, and the chain structure has 0 to 10 carbon atoms. The chain structure is connected to the linker through an oxygen atom, or the chain structure is directly connected to the linker.

5. The positive photosensitive resin composition according to claim 4, characterized in that, The hydrophobic group is selected from one or more of the following structures: Where n = 0 to 10, m = 1 to 5.

6. The positive photosensitive resin composition according to any one of claims 1 to 5, characterized in that, The second thermal crosslinking agent is selected from one or more of the following compounds:

7. The positive photosensitive resin composition according to claim 6, characterized in that, The second thermal crosslinking agent is selected from one or more of the following compounds:

8. The positive photosensitive resin composition according to any one of claims 1 to 5, characterized in that, Based on 100 parts by weight of the alkali-soluble resin, the amount of the first thermal crosslinking agent is 5 to 40 parts by weight, and the amount of the second thermal crosslinking agent is 15 to 40 parts by weight.

9. A cured film, obtained by curing the positive photosensitive resin composition as described in any one of claims 1 to 8.

10. A method for patterning a cured film, comprising the following steps: i) The positive photosensitive resin composition according to any one of claims 1 to 8 is coated on a substrate and dried at 40 to 120°C for 1 to 10 minutes to form a positive photosensitive resin composition film; ii) Expose the film under a mask; iii) Remove the exposed portions of the film using an alkaline developer, develop and clean it; iiii) The developed film is cured and dried at 100-400°C to obtain a cured film containing the desired pattern.

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