A transparent photosensitive polyimide resin, its preparation method and application

Abstract

This invention discloses a transparent photosensitive polyimide resin, its preparation method, and its applications, belonging to the field of polyimide technology. The invention uses hydroxyl-containing (meth)acrylate, organic base, rigid aromatic dianhydride, fluorinated aromatic dianhydride, fluorinated aromatic diamine, and rigid aromatic diamine to prepare a photosensitive resin precursor. This precursor is then mixed with photosensitive additives, solvents, etc., to obtain the transparent photosensitive polyimide resin. The polyimide resin prepared by this invention exhibits excellent photolithography performance. Furthermore, the polyimide film formed after high-temperature curing of the photolithographic pattern possesses high transparency, high heat resistance, high strength and toughness, and low dielectric loss.

Description

Technical Field

[0001] This invention relates to the field of polyimide technology, specifically to a transparent photosensitive polyimide resin, its preparation method, and its applications. Background Technology

[0002] Photosensitive polyimide (PSPI) combines the excellent comprehensive properties of polyimide with the photolithographic patterning performance of photoresist, and has been widely used in microelectronics manufacturing and packaging, flat panel displays, and other fields. Its main applications include chip surface passivation layers, alpha particle masking layers, buffer inner coatings, and interlayer insulating dielectric layers in multilayer circuits. PSPI materials are divided into negative and positive types. Negative PSPI material is produced by introducing photosensitive groups into the main chain structure of a polyimide precursor resin, first forming a photosensitive polyamic ester (PAE) resin; then, it is uniformly mixed with photosensitive additives, crosslinking agents, solvents, etc., to form a negative photosensitive polyimide resin (n-PSPI). The n-PSPI solution is spin-coated onto the surface of a substrate such as a silicon wafer, and after pre-baking, exposure, development, and rinsing, a negative stereolithographic pattern is formed. The developed silicon wafer or other substrate undergoes an imidization reaction at high temperature to obtain the polyimide negative photolithographic pattern. The polyimide film with photolithographic patterns obtained by high-temperature curing exhibits excellent heat resistance, mechanical properties, electrical insulation properties, dielectric properties, corrosion resistance, and high dimensional stability. Because the main chain structure of photosensitive PAE resin contains photosensitive crosslinking groups such as (meth)acrylate, these groups undergo photochemical crosslinking reactions under ultraviolet light, significantly reducing their solubility in the developer and endowing PSPI materials with excellent photolithographic processing performance.

[0003] However, the polyimide films formed after photolithography and high-temperature curing of n-PSPI materials are all yellowish-brown and opaque. This is mainly attributed to the presence of numerous imide rings and conjugated aromatic rings in the main chain structure of the polyimide film resin transformed during the high-temperature curing process. These rings easily form strong intra- and inter-chain charge transfer complexes (CTCs), resulting in strong light absorption in the visible light region and causing the film material to appear yellow or yellowish-brown. In recent years, the technological development in fields such as flat panel displays and optical devices has urgently required the use of colorless and transparent polyimide resins. This necessitates that PSPI materials not only possess excellent photolithographic processability and comprehensive mechanical, heat-resistant, and electrical properties, but also that the polyimide films formed after photolithography and high-temperature curing exhibit excellent transparency.

[0004] Guo Jianwei et al. (CN112979949A) disclosed a transparent photosensitive polyimide resin and its preparation method. A photosensitive PAE resin was obtained by polycondensation of a fluorine-containing, pyridine-ring-modified aromatic diamine monomer (BAFP) and an aromatic diacyl chloride diester containing methacrylate groups in an organic solution. The photosensitive PAE resin was then uniformly mixed with a photosensitizing agent, an active diluent, and an organic solvent to obtain a transparent photosensitive PSPI resin. The polyimide film obtained after photosensitive curing at high temperature showed a transmittance ≥80% at a UV wavelength of 420 nm, a film thermal weight loss temperature of 10% of 360–390 °C, and good photosensitivity. However, its thermal stability needs improvement, and it cannot be used to prepare photolithographic patterns.

[0005] Rong Minzhi et al. (CN110804181A) disclosed a transparent photosensitive polyimide resin and its preparation method. A diamine monomer with a strongly electronegative aliphatic ring structure and an aromatic dianhydride monomer are subjected to a condensation reaction in a solvent solution to form a polyamic acid resin. After imidization, photosensitive groups containing spiropyrans are branched onto the resin side to obtain a modified transparent photosensitive polyimide resin that changes color under ultraviolet light, providing a direct and visual observation of the photomodified region. However, this resin cannot be used to prepare photolithographic patterns. Summary of the Invention

[0006] The purpose of this invention is to provide a transparent photosensitive polyimide resin, its preparation method, and its application. The polyimide resin prepared by this invention has excellent photolithography performance. At the same time, the polyimide film formed after the photolithographic pattern is cured at high temperature has the characteristics of high transparency, high heat resistance, high strength and toughness, high electrical insulation, and low dielectric loss.

[0007] This invention first provides a method for preparing a transparent photosensitive polyimide resin, comprising the following steps:

[0008] (1) Dissolve a mixture of hydroxyl-containing (meth)acrylate, organic base, rigid aromatic dianhydride and fluorine-containing aromatic dianhydride in an organic solvent, and after esterification, form a solution of aromatic diacid diester containing (meth)acrylate groups; further react it under the action of an acyl chloride reagent to form a solution of aromatic diester diacyl chloride containing (meth)acrylate groups.

[0009] (2) At 0–15°C, the mixture solution of aromatic diester diacyl chloride containing (meth)acrylate groups is slowly added dropwise to an organic solution containing fluorinated aromatic diamine and rigid aromatic diamine, and then reacted at room temperature to generate a photosensitive polyamic acid ester resin solution; the photosensitive polyamic acid ester resin solution is precipitated in a poor solvent, and after filtration, washing and drying, a photosensitive polyamic acid ester resin solid is obtained;

[0010] (3) Dissolve the photosensitive polyamide ester resin solid, photosensitive additive, crosslinking agent and polymerization inhibitor in an organic solvent, and obtain the transparent photosensitive polyimide resin after reaction.

[0011] In the above preparation method, in step (1), the hydroxyl-containing (meth)acrylate is at least one of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 1-acryloyloxy-3-propanol, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy-3-tert-butoxypropyl acrylate, 2-isobutenamide ethanol, 1-methacryloyloxy-3-propanol, 2-hydroxy-3-phenoxypropyl methacrylate, 2-hydroxy-3-methoxypropyl methacrylate, 2-hydroxy-3-butoxypropyl methacrylate, 2-hydroxy-3-tert-butoxypropyl methacrylate, 2-hydroxy-3-cyclohexyloxypropyl methacrylate, and 2-hydroxy-3-cyclohexyloxypropyl methacrylate.

[0012] The organic base is at least one selected from triethylamine, pyridine, 2-methylpyridine, 3-methylpyridine, isoquinoline, piperidine, and 3-methyl-piperidine;

[0013] The rigid aromatic dianhydride is at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride.

[0014] The fluorinated aromatic dianhydride is at least one selected from 4,4'-(hexafluoroisopropene)diphthalic anhydride, 4,4'-(trifluoromethylphenylisopropyl)diphthalic anhydride, 1,4-bis(trifluoromethyl)-2,3,5,6-benzenetetracarboxylic acid dianhydride, 4,4'-(4,4'-hexafluoroisopropyldiphenoxy)bis(phthalic anhydride), 4,4'-(trifluoromethyl-m-trifluoromethylphenyl-isopropyl)diphthalic anhydride, 4,4'-(trifluoromethyl-m,m-bistrifluoromethylphenyl-isopropyl)diphthalic anhydride and 9,9-bis(trifluoromethyl)-2,3,6,7-oxanthracenetetracarboxylic dianhydride;

[0015] In step (1), the organic solvent is at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, acetone, cyclohexanone, ethyl acetate, tetrahydrofuran, ethylene glycol monomethyl ether, and ethylene glycol dimethyl ether.

[0016] The acyl chloride reagent is at least one of SOCl2, PCl3, PCl5, oxaloyl chloride, and COCl2.

[0017] In the above preparation method, in step (1), the ratio of the molar number of the hydroxyl-containing (meth)acrylate to the total molar number of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 2:1.

[0018] The molar ratio of the fluorinated aromatic dianhydride to the rigid aromatic dianhydride is 1:0 to 10, preferably 1:0.1 to 5; specifically, it can be 1:0.3, 1:1, 1:3, 1:0.1 or 1:1.5.

[0019] The ratio of the molar number of the organic base to the total molar number of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 1 to 5:1, preferably 2 to 4:1; more preferably 2:1.

[0020] The mass ratio of the organic solvent to the total mass of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 1 to 10:1, preferably 2 to 8:1;

[0021] The ratio of the molar number of the acyl chloride reagent to the total molar number of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 2:1.

[0022] In the above preparation method, in step (2), the fluorinated aromatic diamine is 2,2'-bis(trifluoromethyl-4,4'-diaminobiphenyl), 2,2'-bis(trifluoromethoxy-4,4'-diaminobiphenyl), 3,3'-bis(trifluoromethyl-5,5'-diaminobiphenyl), 1,4-bis(2-trifluoromethyl-4-aminophenoxy)benzene, 1,3-bis(2-trifluoromethyl-4-aminophenoxy)benzene, 4,4'-bis(2-trifluoromethyl-4-aminophenoxy)biphenyl, or 2,2-bis[4-(4-aminophenoxy)phenyl]hexadecyl At least one of the following: fluoropropane, 2,2-bis[4-(2-trifluoromethyl-4-aminophenoxy)phenyl]propane, 3-trifluoromethyl-4,4'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether, N,N'-(2,2'-bis(trifluoromethyl)-[1,1'-diphenyl]-4,4'-diyl)bis(4-aminobenzamide), 3-trifluoromethyl-m-phenylenediamine, tetrafluoro-m-phenylenediamine, tetrafluoro-p-phenylenediamine, 4,4'-octafluorobiphenylenediamine, and 4,4'-diaminooctafluorobiphenyl ether;

[0023] The rigid aromatic diamine is at least one of 4,4'-diaminodiphenyl ether, 1,4-p-phenylenediamine, 4,4'-biphenyldiamine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, and 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane.

[0024] The organic solvent of the organic solution is at least one selected from N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, acetone, cyclohexanone, ethyl acetate, tetrahydrofuran, ethylene glycol monomethyl ether, and ethylene glycol dimethyl ether.

[0025] The unsuitable solvent is at least one selected from water, ethanol, methanol, hexane, and toluene; preferably at least one selected from deionized water, ethanol, and methanol; specifically, it may be deionized water.

[0026] The total molar ratio of the fluorinated aromatic diamine to the rigid aromatic diamine is 100:90-110.

[0027] The molar ratio of the fluorinated aromatic diamine to the rigid aromatic diamine is 1:0 to 10, preferably 1:0.1 to 5; specifically, it can be 1:0.1, 1:0.25, 1:1.5 or 1:0.4.

[0028] The mass ratio of the organic solvent to the total mass of the fluorinated aromatic diamine and the rigid aromatic diamine is 1 to 10:1, preferably 5 to 10:1;

[0029] The mass ratio of the unsuitable solvent to the photosensitive polyamide ester resin solution is 3 to 20:1.

[0030] In the above preparation method, in step (3), the photosensitizer is at least one of benzophenone, dibenzyl ketone, 4-benzoyl-4'-methylbenzophenone, 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, thioxanthone, 2-methylthioxanthone, benzoyl, benzoyl dimethyl ketal, 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, and N-phenylglycine;

[0031] The photocrosslinking agent is at least one of ethylene glycol diethyl ether methacrylate, tetraethylene glycol dimethacrylate, propylene glycol dimethacrylate, cyclohexane dimethacrylate, and 1,4-butanediol dimethacrylate.

[0032] The polymerization inhibitor is at least one selected from hydroquinone, N-nitrosodiphenylamine, N-phenylnaphthalene, p-tert-butylcatechol, phenothiazine, ethylenediaminetetraacetic acid, 1,2-cyclohexanone diaminetetraacetic acid, glycol ether diaminetetraacetic acid, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 5-nitroso-8-hydroxyquinoline, and 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol;

[0033] The organic solvent mentioned in step (3) is at least one of N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), γ-butyrolactone (GBL), acetone, ethyl acetate, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and tert-butanol;

[0034] In step (3), the mass ratio of the photosensitive polyaminate resin solid to the photosensitive additive is 1:0 to 1:0.5, preferably 1:0.01 to 1:0.2;

[0035] The mass ratio of the photosensitive polyamide ester resin solid to the crosslinking agent is 1:0 to 1:0.5, preferably 1:0.01 to 1:0.3;

[0036] The mass ratio of the photosensitive polyamide ester resin solid to the polymerization inhibitor is 1:0 to 1:0.5, preferably 1:0.001 to 1:0.2;

[0037] The mass ratio of the photosensitive polyamide ester resin solid to the organic solvent is 1:0.1 to 1:100, preferably 1:0.5 to 1:10.

[0038] In the above preparation method, in step (1), the esterification reaction is carried out at room temperature and the esterification reaction takes 6 to 12 hours.

[0039] The conditions for further reaction under the action of acyl chloride reagent are: first react at 0-10℃ for 2-6 hours, then react at room temperature for 4-6 hours;

[0040] In step (2), the room temperature reaction time is 6–12 h;

[0041] In step (3), the reaction temperature is room temperature; the reaction time is 2 to 4 hours.

[0042] Specifically, the reaction is carried out under stirring conditions.

[0043] In the above preparation method, the room temperature is known to those skilled in the art, that is, no additional heating is required, and is generally 15 to 35°C.

[0044] The present invention further provides a transparent photosensitive polyimide resin prepared by the above preparation method.

[0045] The application of the aforementioned transparent photosensitive polyimide resin in the preparation of transparent photosensitive polyimide films also falls within the scope of protection of this invention.

[0046] In the above applications, the transparent photosensitive polyimide film is a film with a stereolithographic pattern.

[0047] Finally, the present invention provides a transparent photosensitive polyimide film, which is prepared by a method comprising the following steps:

[0048] The transparent photosensitive polyimide film is obtained by coating the above-mentioned transparent photosensitive polyimide resin, then photolithographically patterning it, and finally curing it at high temperature.

[0049] Specifically, the high-temperature curing temperature is 280–350°C; the high-temperature curing time is 0.5–4 hours.

[0050] The preparation method of the transparent photosensitive polyimide film specifically includes the following steps: the above-mentioned transparent photosensitive polyimide resin coating is applied, and after ultraviolet exposure, development and rinsing, the transparent photosensitive polyimide film is obtained after high-temperature curing.

[0051] The ultraviolet exposure conditions are 10–1000 mJ / cm². 2 ;

[0052] The development time is 10–200 seconds;

[0053] The high-temperature curing conditions are 280–350℃ for 0.5–4 hours;

[0054] The process before ultraviolet exposure also includes a drying step; specifically, the drying is performed at 100±30℃ for 10 to 500 seconds.

[0055] The transparent photosensitive polyimide film has a transmittance of ≥83% at 450nm and ≥90% at 550nm in the ultraviolet light. The film has a thermal weight loss of 5% at a temperature of 506-522℃ and a Tg of ≥330℃. The film has an elongation at break of 49.1% and a Tanδ of 0.0033 at 10GHz.

[0056] The transparent photosensitive polyimide resin prepared by this invention has excellent photolithography performance. The resolution of the photolithographic stereoscopic pattern formed after ultraviolet exposure, development, and rinsing can reach 10 μm. At the same time, the polyimide film formed after high-temperature curing of the photolithographic pattern has excellent transparency and comprehensive performance. The transmittance at a UV wavelength of 450 nm is ≥83%, and the transmittance at 550 nm is ≥90%. It also has excellent thermal stability and heat resistance, with a film thermal weight loss of 5% at 506-522℃ and a Tg ≥330℃. It has good mechanical properties, with an elongation at break of 49.1%. It also has good dielectric properties, with a Tanδ of 0.0033 at 10 GHz. Attached Figure Description

[0057] Figure 1 The UV-Vis spectrum of the transparent photosensitive polyimide film prepared in Example 1;

[0058] Figure 2 The TGA curve of the transparent photosensitive polyimide film prepared in Example 1;

[0059] Figure 3 DMA curve of the transparent photosensitive polyimide film prepared in Example 1;

[0060] Figure 4 The photolithographic pattern is shown for the transparent photosensitive polyimide film prepared in Example 1. Detailed Implementation

[0061] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0062] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0063] In the quantitative experiments in the following examples, three replicate experiments were set up, and the average value of the results was taken.

[0064] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0065] Example 1

[0066] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 7.36 g (0.025 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 33.32 g (0.075 mol) of 4,4'-(hexafluoroisopropene)benzoic anhydride (6FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to produce the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to produce the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0067] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 28.82g (0.09mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB), 2.00g (0.01mol) of 4,4'-diaminodiphenyl ether (4,4'-ODA) solid powder, and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved to obtain an aromatic diamine mixed solution. The temperature of the aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. Then, the reaction was carried out at room temperature for 10h. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0068] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 40g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0069] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds; rinsing with ethyl acetate to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yields a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film has a resolution of 10μm for circular holes (5μm thick); transmittance at 450nm is 90.5%, and at 550nm is 92.5%; Tg is 344℃; the temperature at which 5% thermal weight loss occurs is 515℃; the elongation at break is 49.1%; and the Tanδ at 10GHz is 0.0041.

[0070] The UV-Vis spectrum of the transparent photosensitive polyimide film obtained above is as follows: Figure 1 As shown; the TGA curve is as follows Figure 2 As shown; the DMA curve is as follows Figure 3 As shown; the photolithographic pattern is as follows Figure 4 As shown.

[0071] Example 2

[0072] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 14.71 g (0.05 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 26.01 g (0.05 mol) of 4,4'-(trifluoromethyl-m-trifluoromethylphenyl-isopropyl)diphthalic anhydride (6FBA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0073] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 25.62g (0.08mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB), 4.00g (0.02mol) of 4,4'-diaminodiphenyl ether (4,4'-ODA) solid powder, and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved to obtain an aromatic diamine mixed solution. The aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. The mixture was then reacted at room temperature for 10 hours. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0074] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 50g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0075] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2 Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds, followed by rinsing with ethyl acetate, to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yielded a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film had a resolution of 14μm for the circular holes (5μm thick); transmittance at 450nm was 86.4%, and at 550nm it was 91.9%; Tg was 340℃; the temperature at which 5% thermal weight loss occurred was 519℃; the elongation at break was 22.5%; and the Tanδ at 10GHz was 0.0033.

[0076] Example 3

[0077] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 22.07 g (0.075 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 11.31 g (0.025 mol) of 4,4'-(trifluoromethylphenylisopropyl)diphthalic anhydride (3FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0078] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 17.13g (0.04mol) of 1,4-bis(2-trifluoromethyl-4-aminophenoxy)benzene (6FAPB), 15.26g (0.06mol) of 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) solid powder, and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved to obtain an aromatic diamine mixed solution. The temperature of the aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. Then, the reaction was carried out at room temperature for 10h. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0079] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 55g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0080] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2 Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds; rinsing with ethyl acetate to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yields a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film has a resolution of 15μm for circular holes (5μm thick); transmittance at 450nm is 85.4%, and at 550nm is 91.0%; Tg is 353℃; the temperature at which 5% thermal weight loss occurs is 522℃; the elongation at break is 12.6%; and the Tanδ at 10GHz is 0.0062.

[0081] Example 4

[0082] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 2.94 g (0.01 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 39.98 g (0.09 mol) of 4,4'-(hexafluoroisopropene)dibenzoic anhydride (6FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0083] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 28.82g (0.09mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB), 2.12g (0.01mol) of 2,2'-dimethyl-4,4'-diaminobiphenyl (M-TOLIDINE) solid powder, and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved, yielding an aromatic diamine mixed solution. The aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. The mixture was then reacted at room temperature for 10 hours. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0084] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 35g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0085] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds, followed by rinsing with ethyl acetate, to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yielded a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film had a resolution of 13μm for the circular holes (5μm thick); transmittance of 90.7% at 450nm and 95.7% at 550nm; Tg of 335℃; temperature at which 5% thermal weight loss occurs at 510℃; elongation at break was 37.6%; and Tanδ of 0.0066 at 10GHz.

[0086] Example 5

[0087] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 5.45 g (0.025 mol) of pyromellitic dianhydride (PMDA), 33.32 g (0.075 mol) of 4,4'-(hexafluoroisopropene)dibenzoic anhydride (6FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0088] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 28.82g (0.09mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB), 2.00g (0.01mol) of 4,4'-diaminodiphenyl ether (4,4'-ODA) solid powder, and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved to obtain an aromatic diamine mixed solution. The temperature of the aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. Then, the reaction was carried out at room temperature for 10h. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0089] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 40g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0090] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2 Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds, followed by rinsing with ethyl acetate, to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ for 1 hour yielded a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film had a resolution of 15μm for the circular holes (5μm thick); transmittance at 450nm was 86.4%, and at 550nm it was 90.9%; Tg was 330℃; the temperature at which 5% thermal weight loss occurred was 506℃; the elongation at break was 20.1%; and the Tanδ at 10GHz was 0.0058.

[0091] Example 6

[0092] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 13.09 g (0.06 mol) of pyromellitic dianhydride (PMDA), 23.53 g (0.04 mol) of 4,4'-(trifluoromethyl-m,m-bistrifluoromethylphenyl-isopropyl)diphthalic anhydride (9FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0093] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 12.81g (0.04mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB), 15.26g (0.06mol) of 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) solid powder and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved to obtain an aromatic diamine mixed solution. The aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. The reaction was then carried out at room temperature for 10 hours. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0094] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 50g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0095] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2 Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds; rinsing with ethyl acetate to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yields a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film has a resolution of 10μm for circular holes (5μm thick); transmittance at 450nm is 86.7%, and at 550nm is 91.3%; Tg is 332℃; the temperature at which 5% thermal weight loss occurs is 512℃; the elongation at break is 26.9%; and the Tanδ at 10GHz is 0.0083.

[0096] Example 7

[0097] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 10.91 g (0.05 mol) of pyromellitic dianhydride (PMDA), 22.21 g (0.05 mol) of 4,4'-(hexafluoroisopropene)dibenzoic anhydride (6FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0098] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 35.31g (0.07mol) of 4,4'-bis(2-trifluoromethyl-4-aminophenoxy)biphenyl (6FBAB), 7.63g (0.03mol) of 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) solid powder, and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved to obtain an aromatic diamine mixed solution. The aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. The reaction was then carried out at room temperature for 10 hours. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0099] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 47g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0100] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds, followed by rinsing with ethyl acetate, to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yielded a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film had a resolution of 10μm for the circular holes (5μm thick); transmittance at 450nm was 89.8%, and at 550nm it was 90.7%; Tg was 336℃; the temperature at which 5% thermal weight loss occurred was 509℃; the elongation at break was 35.2%; and the Tanδ at 10GHz was 0.0082.

[0101] Example 8

[0102] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 2.94 g (0.01 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 39.98 g (0.09 mol) of 4,4'-(hexafluoroisopropene)dibenzoic anhydride (6FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacyl chloride dimethacrylate mixture.

[0103] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 28.82g (0.09mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB), 2.00g (0.01mol) of 4,4'-diaminodiphenyl ether (4,4'-ODA) solid powder, and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until all the solid powder was dissolved to obtain an aromatic diamine mixed solution. The temperature of the aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. Then, the reaction was carried out at room temperature for 10h. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0104] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 40g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0105] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2 Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds; rinsing with ethyl acetate to form a precursor resin stereolithographic pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yielded a transparent photosensitive polyimide film stereolithographic pattern. The high-temperature cured PI film had a resolution of 12μm for the circular holes (5μm thick); transmittance at 450nm was 83.8%, and at 550nm was 91.1%; Tg was 338℃; the temperature at which 5% thermal weight loss occurred was 512℃; the elongation at break was 29.1%; and the Tanδ at 10GHz was 0.0086.

[0106] Comparative Example 1

[0107] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 29.42 g (0.1 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to produce a mixture of the corresponding aromatic diacid dimethacrylates. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to produce a mixture of the corresponding aromatic diacid dimethacrylates.

[0108] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 32.02g (0.1mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB) solid powder and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until the solid powder was completely dissolved to obtain an aromatic diamine mixed solution. The aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. The mixture was then reacted at room temperature for 10 hours. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0109] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 60g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0110] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2 Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds, followed by rinsing with ethyl acetate, to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yielded a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film had a resolution of 15μm for the circular holes (5μm thick); transmittance of 88.5% at 450nm and 90.5% at 550nm; Tg of 355℃; temperature at which 5% thermal weight loss occurs at 524℃; elongation at break was 8.4%; and Tanδ was 0.0076 at 10GHz.

[0111] Comparative Example 2

[0112] In a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 26.03 g of 2-hydroxyethyl methacrylate (HEMA), 15.82 g of pyridine, 44.42 g (0.1 mol) of 4,4'-(hexafluoroisopropyl)benzoic anhydride (6FDA), and 200 g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred at room temperature for 6 h to generate the corresponding aromatic diacid dimethacrylate mixture. The product was then reacted with 23.79 g of SOCl2 at 0 °C for 2 h, followed by a reaction at room temperature for 4 h to generate the corresponding aromatic diacid dimethacrylate mixture.

[0113] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 25.44g (0.1mol) of 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) solid powder and 280g of N-methyl-2-pyrrolidone (NMP) were added sequentially. The mixture was stirred until the solid powder was completely dissolved to obtain an aromatic diamine mixed solution. The aromatic diamine mixed solution was cooled to below 10°C using an ice-water bath. The aromatic-diacyl chloride dimethacrylate mixture prepared above was slowly added dropwise to the aromatic diamine mixed solution. The reaction was then carried out at room temperature for 10 hours. The reaction solution was poured into 5L of deionized water, the solid precipitated, filtered, washed, and vacuum dried to obtain photosensitive polyaminate (PAE) resin.

[0114] In a cleanroom equipped with a yellow light, 40g of the above-mentioned photosensitive PAE resin was dissolved in 50g of NMP to form a homogeneous solution; then, 0.4g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 3.2g of ethylene glycol diethyl ether methacrylate (4EM) and 0.2g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 3h to form a transparent photosensitive polyimide resin (PSPI) solution.

[0115] The above-mentioned transparent photosensitive polyimide resin solution was spin-coated onto the surface of a 6-inch wafer. After baking at 110°C for 4 minutes, a photomask was placed on the surface, and ultraviolet lamps (i and g lines) were used at 200 mJ / cm². 2Exposure at a specific energy for 30 seconds; development with a cyclopentanone / NMP mixture (mass ratio 1:1) for 60 seconds, followed by rinsing with ethyl acetate, to form a precursor resin stereolithography pattern on the silicon wafer surface. Curing in a high-temperature nitrogen-filled oven at 350℃ / 1h yielded a transparent photosensitive polyimide film stereolithography pattern. The high-temperature cured PI film had a resolution of 15μm for the circular holes (5μm thick); transmittance at 450nm was 84.5%, and at 550nm it was 90.5%; Tg was 340℃; the temperature at which 5% thermal weight loss occurred was 514℃; the elongation at break was 9.2%; and the Tanδ at 10GHz was 0.0072.

[0116] Table 1. Main properties of the transparent photosensitive polyimides prepared in the examples and comparative examples.

[0117]

[0118] As can be seen from the data in Table 1, the transparent photosensitive polyimide films prepared in the various embodiments of the present invention not only have excellent photolithography performance, with a resolution of 10 μm for circular holes (5 μm thick); excellent transparency, with a transmittance of ≥83% at 450 nm and ≥90% at 550 nm; but also excellent thermal stability and heat resistance, with a temperature of 5% thermal weight loss of 506–522 °C and Tg ≥330 °C; good mechanical properties, with an elongation at break of 49.1%; and good dielectric properties, with Tanδ reaching 0.0033 at 10 GHz.

[0119] Compared to the comparative example, the negative PSPI material prepared by using only rigid aromatic diamine monomers or rigid aromatic dianhydride monomers as photosensitive precursors (PAE resins) still yields transparent photosensitive polyimide films with excellent photolithography performance, transparency, thermal stability, heat resistance, and dielectric properties. However, the high-temperature cured films have poor toughness, with an elongation at break of ≤10%, making them difficult to apply in practice.

Claims

1. A method for preparing a transparent photosensitive polyimide resin, comprising the following steps: (1) Dissolve a mixture of hydroxyl-containing (meth)acrylate, organic base, rigid aromatic dianhydride and fluorine-containing aromatic dianhydride in an organic solvent, and after esterification, form a mixture of aromatic diacid diesters containing (meth)acrylate groups; further react it under the action of an acyl chloride reagent to form a mixture of aromatic diester diacyl chlorides containing (meth)acrylate groups. The hydroxyl-containing (meth)acrylate is 2-hydroxyethyl methacrylate; The organic base is at least one selected from triethylamine, pyridine, 2-methylpyridine, 3-methylpyridine, isoquinoline, piperidine, and 3-methyl-piperidine; The rigid aromatic dianhydride is 3,3',4,4'-biphenyltetracarboxylic dianhydride; The fluorinated aromatic dianhydride is 4,4'-(hexafluoroisopropene)dibenzoic anhydride; the molar ratio of the fluorinated aromatic dianhydride to the rigid aromatic dianhydride is 1:0.3 or 1:0.1; The ratio of the molar number of the hydroxyl-containing (meth)acrylate to the total molar number of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 2:

1. (2) At 0~15℃, the mixture solution of aromatic diester diacyl chloride containing (meth)acrylate groups is slowly added dropwise to an organic solution containing fluorinated aromatic diamine and rigid aromatic diamine, and then reacted at room temperature to generate a photosensitive polyamic acid ester resin solution; the photosensitive polyamic acid ester resin solution is precipitated in a poor solvent, and after filtration, washing and drying, a photosensitive polyamic acid ester resin solid is obtained; The fluorinated aromatic diamine is 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl; The rigid aromatic diamine is 4,4'-diaminodiphenyl ether or 2,2'-dimethyl-4,4'-diaminobiphenyl; The molar ratio of the fluorinated aromatic diamine to the rigid aromatic diamine is 1:0.1; The total molar ratio of the fluorinated aromatic diamine to the rigid aromatic diamine is 100:90~110. (3) Dissolve the photosensitive polyamide ester resin solid, photosensitive additive, crosslinking agent and polymerization inhibitor in an organic solvent, and obtain the transparent photosensitive polyimide resin after reaction.

2. The preparation method according to claim 1, characterized in that: In step (1), the organic solvent is N methyl 2 Pyrrolidone, N,N Dimethylacetamide, N,N Dimethylformamide, dimethyl sulfoxide, gamma At least one of butyrolactone, acetone, cyclohexanone, ethyl acetate, tetrahydrofuran, ethylene glycol monomethyl ether, and ethylene glycol dimethyl ether; The acyl chloride reagent is at least one of SOCl2, PCl3, PCl5, oxaloyl chloride, and COCl2.

3. The preparation method according to claim 1 or 2, characterized in that: In step (1), the ratio of the number of moles of the organic base to the total number of moles of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 1 to 5:1; The mass ratio of the organic solvent to the total mass of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 1 to 10:1; The ratio of the molar number of the acyl chloride reagent to the total molar number of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 2:

1.

4. The preparation method according to claim 3, characterized in that: In step (1), the ratio of the number of moles of the organic base to the total number of moles of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 2~4:1; The ratio of the mass of the organic solvent to the total mass of the fluorinated aromatic dianhydride and the rigid aromatic dianhydride is 2 to 8:

1.

5. The preparation method according to claim 1 or 2, characterized in that: In step (2), the organic solvent of the organic solution is N. methyl 2 Pyrrolidone, N,N Dimethylacetamide, N,N Dimethylformamide, dimethyl sulfoxide, gamma At least one of butyrolactone, acetone, cyclohexanone, ethyl acetate, tetrahydrofuran, ethylene glycol monomethyl ether, and ethylene glycol dimethyl ether; The unsuitable solvent is at least one of water, ethanol, methanol, hexane, and toluene; The mass ratio of the organic solvent to the total mass of the fluorinated aromatic diamine and the rigid aromatic diamine is 1 to 10:1; The mass ratio of the unsuitable solvent to the photosensitive polyamide ester resin solution is 3~20:

1.

6. The preparation method according to claim 5, characterized in that: In step (2), the undesirable solvent is at least one of deionized water, ethanol, and methanol; The mass ratio of the organic solvent to the total mass of the fluorinated aromatic diamine and the rigid aromatic diamine is 5 to 10:

1.

7. The preparation method according to claim 1 or 2, characterized in that: In step (3), the photosensitizing agent is benzophenone, dibenzyl ketone, or 4... benzoyl 4' Methylbenzophenone, 2,2' Diethoxyacetophenone, 2 hydroxyl 2 Methyl acetone, 1 Hydroxycyclohexylphenyl ketone, thioxanone, 2 Methylthioxanone, benzoyl, benzoyldimethyl ketal, 1 Phenyl 1,2 Butanedione 2 (0 methoxycarbonyl) oxime, 1 Phenyl 1,2 propylene glycol 2 (0 methoxycarbonyl) oxime, 1 Phenyl 1,2 propylene glycol 2 (0 ethoxycarbonyl) oxime, 1 Phenyl 1,2 propylene glycol 2 (0 benzoyl) oxime, and N At least one of phenylglycine; The crosslinking agent is ethylene glycol diethyl ether methacrylate, tetraethylene glycol dimethacrylate, propylene glycol dimethacrylate, cyclohexane dimethacrylate, and 1,4-diethyl ether methacrylate. At least one of butanediol dimethacrylate; The polymerization inhibitor is hydroquinone, N Nitrosaminoglycans, N Phenylenol, p-tert-butylcatechol, phenothiazine, ethylenediaminetetraacetic acid, 1,2 Cyclohexanone diaminetetraacetic acid, diol ether diaminetetraacetic acid, 1 Nitros 2 Naphthol, 2 Nitros 1 Naphthol, 5 Nitros 8 Hydroxyquinoline and 2 Nitros 5 (N Ethyl N At least one of sulfopropylaminophenol; The organic solvent mentioned in step (3) is N methyl 2 Pyrrolidone (NMP), N,N Dimethylacetamide (DMAc), N,N Dimethylformamide (DMF), dimethyl sulfoxide (DMSO), gamma At least one of the following: butyrolactone (GBL), acetone, ethyl acetate, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and tert-butanol; In step (3), the mass ratio of the photosensitive polyaminate resin solid to the photosensitive additive is 1:0 to 1:0.5; The mass ratio of the photosensitive polyamide ester resin solid to the crosslinking agent is 1:0 to 1:0.5; The mass ratio of the photosensitive polyamide ester resin solid to the polymerization inhibitor is 1:0 to 1:0.5; The mass ratio of the photosensitive polyamide ester resin solid to the organic solvent is 1:0.1 to 1:

100.

8. The preparation method according to claim 7, characterized in that: In step (3), the mass ratio of the photosensitive polyaminate resin solid to the photosensitive additive is 1:0.01 to 1:0.2; The mass ratio of the photosensitive polyamide ester resin solid to the crosslinking agent is 1:0.01 to 1:0.3; The mass ratio of the photosensitive polyamide ester resin solid to the polymerization inhibitor is 1:0.001 to 1:0.2; The mass ratio of the photosensitive polyamide ester resin solid to the organic solvent is 1:0.5 to 1:

10.

9. The preparation method according to claim 1 or 2, characterized in that: In step (1), the esterification reaction is carried out at room temperature; the esterification reaction takes 6 to 12 hours. The conditions for further reaction under the action of acyl chloride reagent are: first react at 0~10℃ for 2~6 h, then react at room temperature for 4~6 h; In step (2), the room temperature reaction time is 6~12 h; In step (3), the reaction temperature is room temperature; the reaction time is 2-4 h.

10. The transparent photosensitive polyimide resin prepared by the preparation method according to any one of claims 1-9.

11. The use of the transparent photosensitive polyimide resin of claim 10 in the preparation of transparent photosensitive polyimide films.

12. The application according to claim 11, characterized in that: The transparent photosensitive polyimide film is a film with a stereolithographic pattern.

13. A transparent photosensitive polyimide film, characterized in that: The transparent photosensitive polyimide film is prepared by a method comprising the following steps: The transparent photosensitive polyimide resin coating as described in claim 10 is used, followed by photolithography and high-temperature curing to obtain the transparent photosensitive polyimide film.

14. The transparent photosensitive polyimide film according to claim 13, characterized in that: The high-temperature curing temperature is 280~350℃; the high-temperature curing time is 0.5~4 h.

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