Modified phenol-formaldehyde resin, method for producing the same, and use thereof

Abstract

The application relates to the field of photoetching technology, in particular to a modified phenolic resin and a preparation method and application thereof. The modified phenolic resin is prepared from the following raw materials: linear phenolic resin oligomer, phenolic substance containing a reactive double bond and phenyl phosphinic dichloride; the linear phenolic resin oligomer has the following general formula: wherein n is an integer between 1 and 5. The linear phenolic resin oligomer containing carboxyl groups is subjected to polycondensation with the phenolic substance containing a reactive double bond through the phenyl phosphinic dichloride to obtain the modified phenolic resin; the resin structure contains polar groups such as carboxyl groups and phosphorus-oxygen groups, thereby significantly enhancing the adhesion to a photoetching substrate; meanwhile, the resin has good compatibility with quantum dots, and high-resolution quantum dot photoetching patterning can be realized.

Description

Technical Field

[0001] This invention relates to the field of photolithography, and in particular to a modified phenolic resin, its preparation method, and its applications. Background Technology

[0002] Quantum dots, as a type of semiconductor nanocrystalline material, combine the advantages of inorganic semiconductors in bandgap modulation with the processability of organic semiconductors. They possess characteristics such as small size, high color purity, high luminous efficiency, tunable emission spectrum, and solution-processability, enabling excellent display effects such as high color gamut and high brightness. They show significant application potential in display technology and micro / nano devices such as optoelectronic detection. To achieve high-resolution, large-scale device manufacturing, combining quantum dots with traditional semiconductor photolithography processes (especially negative photoresists) is one of the mainstream technical routes. As a key material in the photolithography process, the chemical composition and physical properties of photoresist directly affect various parameters in photolithographic patterning, including linewidth, roughness, resolution, and contrast, thus influencing the electrical and optical performance of the device. Photoresists are typically composed of resin, photoinitiator, solvent, and other functional additives. Among these, the resin, as the continuous phase and film-forming matrix, has a significant impact on the overall performance of the photoresist.

[0003] Quantum dots, as colloidal nanocrystals, are inherently prone to aggregation and phase separation. To maintain their stability and suppress aggregation, their surfaces are typically coated with long-chain alkyl ligands (such as oleic acid and oleylamine). While these ligands improve the dispersion stability of quantum dots, their surfaces exhibit significant hydrophobicity, resulting in poor interfacial compatibility and low interfacial adhesion energy with common hydrophilic substrates (such as SiO2, ITO, or glass). In subsequent photolithography processes, especially during spin coating and developer rinsing, quantum dot films are highly susceptible to localized or complete detachment from the substrate, severely impacting pattern fidelity and device reliability. To improve the bonding strength between quantum dots and the substrate, ligand exchange is currently the most common method. However, this method often introduces defects into the quantum dot surface, leading to a decrease in its optical performance.

[0004] In quantum dot photolithography patterning, the compatibility between quantum dots and photoresist is also crucial. Good compatibility helps the quantum dots disperse uniformly in the photoresist, avoiding agglomeration that affects the uniformity and resolution of the pattern. Furthermore, the adhesion of the photoresist to the substrate is also critical. If the adhesion is insufficient, even if the quantum dots are embedded in the colloidal network, the entire photoresist film may still peel off from the substrate, leading to patterning failure.

[0005] Therefore, developing photoresist resins that have both good compatibility with quantum dots and good adhesion to substrates is of great significance for the development of quantum dot photolithographic patterning.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a modified phenolic resin, its preparation method, and its application. The modified phenolic resin of this invention has polar groups, good adhesion to photolithography substrates, and good compatibility with quantum dots, enabling high-resolution quantum dot photolithography patterning.

[0008] To achieve the above-mentioned objectives of the present invention, the first aspect of the present invention provides a modified phenolic resin, the raw materials for which include: linear phenolic resin oligomer, phenolic substances containing reactive double bonds, and phenylphosphonic dichloride; The linear phenolic resin oligomer has the structure shown in general formula I: (I); Where n is an integer between 1 and 5.

[0009] In a specific embodiment of the present invention, the phenolic substance containing reactive double bonds includes at least one of p-hydroxycinnamic acid, methyl p-hydroxycinnamate, 4-maleimide phenol, 4-(6-(acryloyloxy)hexyloxy)phenol, p-hydroxystyrene, hydroquinone monomethacrylate, and allylphenolic resin.

[0010] In a specific embodiment of the present invention, the amounts of the linear phenolic resin oligomer and the phenolic substance containing reactive double bonds are both calculated based on the phenolic hydroxyl content. The molar amount of the phenolic substance containing reactive double bonds accounts for 1% to 30% of the total molar amount of the linear phenolic resin oligomer and the phenolic substance containing reactive double bonds, preferably 5% to 20%.

[0011] In a specific embodiment of the present invention, the ratio of the total molar number of the linear phenolic resin oligomer and the phenolic substance containing reactive double bonds to the molar number of the phenylphosphonic dichloride is 1:(0.01~0.2), preferably 1:(0.05~0.15).

[0012] The second aspect of the present invention provides a method for preparing the modified phenolic resin provided in the first aspect, comprising the following steps: a linear phenolic resin oligomer and a phenolic substance containing a reactive double bond react with phenylphosphonic dichloride in a solvent under the action of an acid-binding agent.

[0013] In a specific embodiment of the present invention, the acid-binding agent comprises triethylamine. Further, the molar ratio of the acid-binding agent to the phenylphosphonic dichloride is (2~3):1.

[0014] In a specific embodiment of the present invention, the reaction temperature is 15~30℃ and the reaction time is 1~3h.

[0015] A third aspect of the present invention provides a photoresist comprising the modified phenolic resin provided in the first aspect of the present invention.

[0016] In a specific embodiment of the present invention, the photoresist further includes a polyene compound, a photoinitiator, and a solvent.

[0017] In a specific embodiment of the present invention, the polyene bond compound includes at least one of pentaerythritol triacrylate and pentaerythritol tetraacrylate.

[0018] In a specific embodiment of the present invention, the solvent includes propylene glycol methyl ether acetate.

[0019] In a specific embodiment of the present invention, the photoresist comprises, by weight, 10-20 parts of modified phenolic resin, 25-35 parts of polyene compound, 2-6 parts of photoinitiator, and 40-60 parts of solvent.

[0020] In a specific embodiment of the present invention, the photoresist further includes quantum dots. Further, the quantum dots constitute 20% to 30% of the mass of the photoresist.

[0021] The fourth aspect of the present invention provides a method for patterning photoresist, comprising the following steps: placing the photoresist provided in the third aspect of the present invention on a substrate, performing ultraviolet light exposure treatment under the cover of a mask, and then developing the pattern using a developer.

[0022] In a specific embodiment of the present invention, the developing solution comprises propylene glycol methyl ether acetate.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In this invention, a modified phenolic resin is obtained by polycondensation of a linear phenolic resin oligomer containing a carboxyl group and a phenolic substance containing a reactive double bond using phenylphosphonic dichloride. The resin structure contains polar groups such as carboxyl and phosphoroxy groups, which significantly enhances the adhesion to the photolithography substrate. At the same time, the resin has good compatibility with quantum dots and can realize high-resolution quantum dot photolithography patterning. (2) By introducing phenolic substances containing reactive double bonds into the modified phenolic resin, the present invention can also improve the photocuring rate of the resin, which is beneficial to obtaining patterns with high resolution, good structural stability and uniform light-emitting pixels. (3) The modified phenolic resin of the present invention has good solubility in solvents such as propylene glycol methyl ether acetate, and propylene glycol methyl ether acetate can be used as a developer, which has good compatibility with existing photolithography processes. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the synthesis route of the modified phenolic resin provided in the embodiments of the present invention; Figure 2 The 1H NMR spectrum of the modified phenolic resin PFP-CA15-20% and its raw materials provided in the embodiments of the present invention; Figure 3 Carbon NMR spectra of the modified phenolic resin PFP-CA15-20% and its raw materials provided in the embodiments of the present invention; Figure 4 The proton nuclear magnetic resonance spectra of the modified phenolic resins provided in different embodiments of the present invention; Figure 5 Carbon NMR spectra of the modified phenolic resins provided in different embodiments of the present invention; Figure 6 This is a mass spectrum of the linear phenolic resin oligomer PF provided in an embodiment of the present invention; Figure 7 Mass spectra of modified phenolic resins containing different phenolic substances with reactive double bonds provided in different embodiments of the present invention; Figure 8 Mass spectra of modified phenolic resins containing different phenylphosphonic dichlorides provided in different embodiments of the present invention; Figure 9 The viscosity test results of the modified phenolic resin PFP-CA15-20% provided in the embodiments of the present invention; Figure 10 Viscosity test results of modified phenolic resins containing different phenolic substances with reactive double bonds provided in different embodiments of the present invention; Figure 11 The solubility of modified phenolic resins in PGMEA according to different embodiments of the present invention; Figure 12 This is a diagram showing the effect of photoresist curing according to an embodiment of the present invention; Figure 13 The TGA test results of the modified phenolic resin PFP-CA15-20% provided in the embodiments of the present invention; Figure 14 This is a photomicrograph of a pattern obtained using photoresist in an embodiment of the present invention; Figure 15This is a photomicrograph of a pattern obtained using photoresist in an embodiment of the present invention; Figure 16 This is a photomicrograph of a pattern obtained using photoresist in an embodiment of the present invention; Figure 17 Four photomicrographs of patterns obtained using photoresist in an embodiment of the present invention; Figure 18 This is a photomicrograph of a pattern obtained using photoresist in an embodiment of the present invention under a fluorescent field; Figure 19 The results show the thickness of the striped pattern measured using a protractor. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0027] The first aspect of the present invention provides a modified phenolic resin, the raw materials for which include: linear phenolic resin oligomer, phenolic substances containing reactive double bonds, and phenylphosphonic dichloride; Linear phenolic resin oligomers have the structure shown in general formula I: (I); Where n is an integer between 1 and 5, such as 1, 2, 3, 4 or 5.

[0028] This invention relates to a modified phenolic resin obtained by polycondensing a linear phenolic resin oligomer containing carboxyl groups with a phenolic substance containing reactive double bonds using phenylphosphonic dichloride. This resin structure contains polar groups such as carboxyl and phospho groups, significantly enhancing its adhesion to photolithography substrates. Simultaneously, this resin exhibits good compatibility with quantum dots, enabling high-resolution quantum dot photolithography patterning. Specifically, the modified phenolic resin is mainly prepared by the condensation reaction of phenolic hydroxyl groups in the linear phenolic resin oligomer, phenolic hydroxyl groups in the phenolic substance containing reactive double bonds, and phosphonic chloride groups of phenylphosphonic dichloride.

[0029] Furthermore, the modified phenolic resin of the present invention has good solubility in solvents such as propylene glycol methyl ether acetate (PGMEA), and propylene glycol methyl ether acetate can be used as a developer, which has good compatibility with existing photolithography processes.

[0030] In a specific embodiment of the present invention, the preparation of the linear phenolic resin oligomer includes: reacting p-hydroxyphenylpropionic acid and an aqueous formaldehyde solution in a solvent at 70-80°C for 24-60 h. The solvent includes water. Further, after the reaction is complete, the mixture is freeze-dried to remove water.

[0031] In a specific embodiment of the present invention, the molar ratio of p-hydroxyphenylpropionic acid to formaldehyde is 1:(0.8~1.2), preferably 1:1.

[0032] The linear phenolic resin oligomer of the present invention retains the advantages of traditional phenolic resins, such as high stability, while introducing the functional group carboxyl.

[0033] In specific embodiments of the present invention, the phenolic substance containing reactive double bonds includes at least one selected from p-hydroxycinnamic acid, methyl p-hydroxycinnamate, 4-maleimide-phenol, 4-(6-(acryloyloxy)hexyloxy)phenol, p-hydroxystyrene, hydroquinone monomethacrylate, and allylphenolic resin. The present invention, by introducing phenolic substances containing reactive double bonds into modified phenolic resin, effectively improves the photocuring rate of the resin, which is beneficial for obtaining patterns with high resolution, good structural stability, and uniform luminescent pixels.

[0034] In a specific embodiment of the present invention, the amounts of linear phenolic resin oligomers and phenolic substances containing reactive double bonds are both calculated based on the content of phenolic hydroxyl groups. The molar amount of phenolic substances containing reactive double bonds accounts for 1% to 30% of the total molar amount of linear phenolic resin oligomers and phenolic substances containing reactive double bonds. Specifically, it can be 1%, 3%, 5%, 10%, 15%, 20%, 25%, 30%, or any combination thereof, preferably 5% to 20%. By controlling the ratio of the two within the above range, an appropriate amount of photocrosslinking sites can be effectively introduced into the resin, thereby obtaining rapid photocuring response and high crosslinking density, ensuring patterning accuracy and structural stability; and improving the adhesion of the resin to the photolithography substrate, while ensuring the solubility of the resin in PGMEA.

[0035] In a specific embodiment of the present invention, the ratio of the total molar number of phenolic hydroxyl groups in the linear phenolic resin oligomer and the phenolic substance containing reactive double bonds to the molar number of phenylphosphonic dichloride is 1:(0.01~0.2), specifically it can be a range of 1:0.01, 1:0.03, 1:0.05, 1:0.08, 1:0.1, 1:0.12, 1:0.15, 1:0.18, 1:0.2 or any combination thereof, preferably 1:(0.05~0.15). Using phenylphosphonic dichloride in amounts satisfying the above range allows for the polycondensation and linkage of the linear phenolic resin oligomer and the phenolic substance containing reactive double bonds. The resulting modified phenolic resin exhibits high viscosity, significantly improving adhesion to photolithography substrates, while maintaining good solubility in PGMEA, ensuring compatibility with existing photolithography processes.

[0036] The second aspect of the present invention provides a method for preparing the modified phenolic resin provided in the first aspect, comprising the following steps: a linear phenolic resin oligomer and a phenolic substance containing a reactive double bond react with phenylphosphonic dichloride in a solvent under the action of an acid-binding agent.

[0037] Figure 1 This is a schematic diagram of the synthesis route of the modified phenolic resin provided by the present invention, wherein p-hydroxycinnamic acid is used as an example of a phenolic substance containing reactive double bonds.

[0038] In a specific embodiment of the present invention, the amounts of linear phenolic resin oligomers and phenolic substances containing reactive double bonds are both calculated based on the content of phenolic hydroxyl groups. The molar amount of phenolic substances containing reactive double bonds accounts for 1% to 25% of the total molar amount of linear phenolic resin oligomers and phenolic substances containing reactive double bonds. That is, the molar ratio of linear phenolic resin oligomers (calculated based on phenolic hydroxyl groups) to phenolic substances containing reactive double bonds (calculated based on phenolic hydroxyl groups) is (3 to 99): 1, preferably (4 to 19): 1.

[0039] In a specific embodiment of the present invention, the acid-binding agent includes triethylamine. Further, the molar ratio of the acid-binding agent to phenylphosphonic dichloride is (2~3):1, specifically it can be a range of 2:1, 2.2:1, 2.4:1, 2.5:1, 2.6:1, 2.8:1, 3:1, or any two of these.

[0040] In a specific embodiment of the present invention, the reaction temperature is 15~30℃, specifically 15℃, 20℃, 25℃, 30℃ or any combination thereof, and the reaction time is 1~3 h, specifically 1 h, 1.5 h, 2 h, 2.5 h, 3 h or any combination thereof.

[0041] In a specific embodiment of the present invention, the solvent used in the preparation of the modified phenolic resin includes, but is not limited to, tetrahydrofuran.

[0042] In a specific embodiment of the present invention, the preparation of the modified phenolic resin is carried out under a protective atmosphere.

[0043] In a specific embodiment of the present invention, the preparation of modified phenolic resin may include: first, dissolving linear phenolic resin oligomers and phenolic substances containing reactive double bonds in a solvent, then adding an acid-binding agent and stirring to form a homogeneous solution; then removing oxygen by vacuuming and purging with nitrogen, and adding phenylphosphonic dichloride dropwise at 0~5°C, and after the addition is complete, restoring the reaction to room temperature; after the reaction is completed, filtering to collect the organic phase, removing the solvent, and drying to obtain modified phenolic resin.

[0044] A third aspect of the present invention provides a photoresist comprising the modified phenolic resin provided in the first aspect of the present invention.

[0045] In a specific embodiment of the present invention, the photoresist further includes a polyene compound, a photoinitiator, and a solvent.

[0046] In a specific embodiment of the present invention, the polyene compound includes at least one of pentaerythritol triacrylate (PETA) and pentaerythritol tetraacrylate (PET4A).

[0047] In a specific embodiment of the present invention, the solvent includes propylene glycol methyl ether acetate (PGMEA).

[0048] In specific embodiments of the present invention, the photoinitiator includes, but is not limited to, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819).

[0049] In a specific embodiment of the present invention, the photoresist comprises, by weight, 10-20 parts of modified phenolic resin, 25-35 parts of polyene compound, 2-6 parts of photoinitiator, and 40-60 parts of solvent.

[0050] In different embodiments, the amounts of each component in the photoresist, by weight, can be exemplarily as follows: The amount of modified phenolic resin can be 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, or any combination thereof. The amount of polyene compound can be 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, or any combination thereof; The amount of photoinitiator can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, or any combination thereof; The amount of solvent used can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, or any combination thereof.

[0051] In a specific embodiment of the present invention, the photoresist further includes quantum dots, specifically modified oil-soluble cadmium selenide quantum dots. Further, the mass percentage of quantum dots in the photoresist is 20% to 30%, specifically within the range of 20%, 22%, 25 wt%, 28%, 30%, or any combination thereof.

[0052] The present invention also provides an optional method for preparing photoresist, specifically comprising: mixing and dissolving the above components in proportion.

[0053] The fourth aspect of the present invention provides a method for patterning photoresist, comprising the following steps: placing the photoresist provided in the third aspect of the present invention on a substrate, performing ultraviolet light exposure treatment under the cover of a mask, and then developing the pattern using a developer.

[0054] The modified phenolic resin of the present invention has a high viscosity, thereby the resulting photoresist has good adhesion to the photolithography substrate; and the modified phenolic resin has good solubility in PGMEA, and can be used as a developer.

[0055] In specific embodiments of the present invention, the substrate includes, but is not limited to, hydrophilic substrates, such as glass.

[0056] In a specific embodiment of the present invention, the specific operation of depositing photoresist on the substrate may include, but is not limited to: spin-coating photoresist onto the substrate surface, and then performing a pre-baking process. The pre-baking temperature may be 95~105℃, and the pre-baking time may be 20~40 s.

[0057] In a specific embodiment of the present invention, the developing solution includes propylene glycol methyl ether acetate (PGMEA).

[0058] In a specific embodiment of the present invention, the wavelength of the ultraviolet light is 350~380 nm, the exposure time of the ultraviolet light is ≥5s, and the exposure energy of the ultraviolet light is 50~250 mJ / cm². 2 .

[0059] In different embodiments, the wavelength of the ultraviolet light can be 350 nm, 360 nm, 370 nm, 380 nm, or any combination thereof; the exposure time of the ultraviolet light can be 5 s, 10 s, 15 s, 20 s, or any combination thereof, such as 5~10 s, 10~20 s, etc.; the exposure energy of the ultraviolet light can be 50 mJ / cm². 2 100 mJ / cm 2 150 mJ / cm 2 200 mJ / cm 2 250 mJ / cm 2Or a range consisting of any two of them.

[0060] Example 1 This embodiment provides a method for preparing modified phenolic resin (PFP-CA15-20%), and the synthetic route is as follows: Figure 1 It includes the following steps: (1) Synthesis of linear phenolic resin oligomer PF: p-hydroxyphenylpropionic acid 1 (66.4680 g, 0.4 mol), 37 wt% formaldehyde aqueous solution (32.4324 g, containing 0.4 mol formaldehyde molecules), and 150 mL deionized water were added to a 500 mL round-bottom flask and stirred at 75 °C for 48 h. After the reaction was completed, the product was freeze-dried to remove water, with a yield of 93%.

[0061] (2) Synthesis of modified phenolic resin (PFP-CA15-20%): PF (1.5215 g, containing approximately 8.5 mmol of phenolic hydroxyl groups) and CA (0.2460 g, 1.5 mmol) were added to a 50 mL round-bottom flask and dissolved in 10 mL of anhydrous tetrahydrofuran. Triethylamine (0.2424 g, 2.4 mmol) was then added and stirred at room temperature until completely dissolved, forming a homogeneous and transparent solution. Oxygen was then removed by three vacuum-nitrogen cycles. Benzyl dichloro(PPDC) (0.1950 g, 1 mmol) was added dropwise at 0 °C. After the addition was complete, the mixture was allowed to return to room temperature for 2 h. After the reaction was complete, triethylamine hydrochloride was removed by vacuum filtration. The organic solvent was evaporated to dryness and then dried at 50 °C to constant weight to obtain the target product with a yield of 83.1%.

[0062] Take 110 mg of the prepared modified phenolic resin, 190 mg of PETA, 27 mg of photoinitiator 819 and 327 mg of PGMEA, stir and mix to form a clear and transparent solution, and obtain a photoresist solution without quantum dots.

[0063] Take the above-mentioned quantum dot-free photoresist solution, add a certain amount of modified oil-soluble cadmium selenide quantum dot solution to it, and stir until uniformly mixed to obtain a quantum dot-containing photoresist; wherein, the mass percentage of quantum dots in the quantum dot-containing photoresist is 25%. One quantum dot-containing photoresist is a green quantum dot-containing photoresist prepared using a green quantum dot solution, with a mass fraction of 35%; the other quantum dot-containing photoresist is a red quantum dot-containing photoresist prepared using a red quantum dot solution, with a mass fraction of 40%. In this embodiment, the modified oil-soluble cadmium selenide quantum dot solution (manufacturer: Beijing Beida Jubang Technology Co., Ltd.) is only an illustrative example and should not be construed as a limitation on the type and source of quantum dots.

[0064] Examples 2-7 Examples 2-7 follow the preparation method of Example 1, except that the amount of each substance in step (2) of the preparation of the modified phenolic resin is different. The specific amount of each substance in step (2) and the yield of the target product are shown in Table 1.

[0065] Table 1. Synthesis of modified phenolic resins in Examples 2-7

[0066] Example 8 Example 8 follows the preparation method of Example 1, except that the phenolic substance containing reactive double bonds is different in step (2) of the preparation of the modified phenolic resin.

[0067] Step (2) of this embodiment includes the synthesis of modified phenolic resin (PFP-FR15-20%): PF (1.5215 g, containing approximately 8.5 mmol of phenolic hydroxyl groups) and allyl phenolic resin (0.2205 g, containing approximately 1.5 mmol of phenolic hydroxyl groups) were added to a 50 mL round-bottom flask, dissolved in 10 mL of anhydrous tetrahydrofuran, and then triethylamine (0.2424 g, 2.4 mmol) was added. The mixture was stirred at room temperature until completely dissolved, forming a homogeneous and transparent solution. Then, oxygen was removed by three vacuum-nitrogen cycles, and phenylphosphonic dichloroPPDC (0.1950 g, 1 mmol) was added dropwise at 0 °C. After the addition was complete, the mixture was allowed to return to room temperature for 2 h. After the reaction was completed, triethylamine hydrochloride was removed by vacuum filtration, and the organic solvent was evaporated to dryness and then dried at 50 °C to constant weight to obtain the target product with a yield of 93.8%. The allylphenolic resin was prepared according to the preparation method of allylphenolic resin FR described in Example 1 of the patent application with publication number CN116731270A.

[0068] Experimental Example 1 Figure 2 and Figure 3 The figures show the 1H NMR and 1C NMR spectra of the modified phenolic resin PFP-CA15-20% and its raw materials from Example 1 of this invention. As can be seen from the figures, the modified phenolic resin with the corresponding structure was synthesized.

[0069] Figure 4 and Figure 5 The figures show the 1H and 1C NMR spectra of the modified phenolic resins provided in Examples 1-5 of this invention. Based on the 1H NMR spectra, it can be seen that by changing the amounts of PF and p-hydroxycinnamic acid, the proportion of crosslinking groups (reactive double bonds) in the modified phenolic resins in Examples 1-5 can be effectively controlled. The areas of peak a and peak c in the 1H NMR spectra were integrated, and their ratios were basically consistent with the theoretical values.

[0070] Figure 6 This is a mass spectrum of the linear phenolic resin oligomer PF provided in an embodiment of the present invention. Figure 7 These are mass spectra of the modified phenolic resins provided in Examples 1-5 of this invention. Figure 8 These are mass spectra of the modified phenolic resins provided in Examples 1, 6-7 of this invention. The mass spectra also demonstrate the successful introduction of characteristic groups into the modified phenolic resins.

[0071] Experiment Example 2 The viscosity of the modified phenolic resin PFP-CA15-20% prepared in Example 1 was tested using a rheometer, and the test results are as follows: Figure 9 As shown. From Figure 9 As can be seen from this, when the shear rate is 0.01~1 s... -1 At that time, the viscosity of the modified phenolic resin PFP-CA15-20% was 450 Pa·s.

[0072] The modified phenolic resins containing different phenolic substances with reactive double bonds from Examples 1-5 were respectively prepared into PGMEA solutions with a mass fraction of 80 wt%. The viscosities of these solutions were then measured using a cone-plate viscometer. The test results are shown below. Figure 10 .from Figure 10 As can be seen, the viscosity of the solution gradually increases as the proportion of phenolic substances containing reactive double bonds introduced into the modified phenolic resin increases.

[0073] The modified phenolic resins of Examples 1-7 were respectively prepared into PGMEA solutions with a mass fraction of 50 wt% modified phenolic resin. The corresponding solution photographs are shown below. Figure 11 As shown. The modified phenolic resins of Examples 1-7 all exhibit good solubility in PGMEA. The solubility of the modified phenolic resins tends to decrease with increasing proportion of p-hydroxycinnamic acid, but they can still dissolve under the aforementioned conditions.

[0074] The quantum dot-free photoresist solutions of Examples 1-7 were exposed to a 365 nm LED UV lamp for 5-10 seconds (exposure energy of 50-250 mJ / cm²). 2 All of these can achieve complete curing. Taking the quantum dot-free photoresist solution from Example 1 as an example, its curing (exposure energy approximately 150 mJ / cm²) can achieve complete curing. 2 (The following photo is as follows) Figure 12 As shown.

[0075] Figure 13 The TGA test results of the modified phenolic resin PFP-CA15-20% of Example 1 of the present invention are shown in the figure. As can be seen from the figure, PFP-CA15-20% can still maintain more than 95% of its mass at 200℃, indicating that the modified phenolic resin of the present invention has good thermal stability.

[0076] Experimental Example 3 The quantum dot-free photoresist solution prepared in Example 1 was uniformly spin-coated (1000 r / min, 30 s) onto a clean glass substrate, preheated at 100°C for 30 s on a heated stage, and then a patterned mask was placed over the spin-coated glass substrate. The substrate was then exposed to a 365 nm LED UV lamp for 10 s (exposure energy approximately 150 mJ / cm²). 2 Then, the image is ultrasonically developed in PGMEA developer for 5-10 seconds to obtain the pattern on the mask.

[0077] Photomicrographs of patterns obtained using different masks are shown below. Figures 14-17 As shown in the figure, the photoresist without quantum dots can be used to lithographically obtain clear square patterns and rectangles of different widths, with the smallest width reaching 2 μm.

[0078] The photoresist solutions containing red quantum dots and green quantum dots prepared in Example 1 were uniformly spin-coated (1000 r / min, 30 s) onto clean glass substrates, respectively. The substrates were then preheated at 100 °C for 30 s on a heated stage. A patterned mask was then placed over the spin-coated glass substrate, and the substrates were exposed to a 365 nm LED UV lamp for 10 s (exposure energy approximately 150 mJ / cm²). 2 Then, the image is ultrasonically developed in PGMEA developer for 5-10 seconds to obtain the pattern on the mask.

[0079] Micrographs of patterns obtained using photoresist solutions containing sub-dots under a fluorescence field, as shown below. Figure 18 As shown in the figure, the photoresist containing quantum dots can be photolithographically reproduced to obtain clear 50 μm squares, 20 μm squares, 10 μm stripes, and 5 μm stripes, as well as various large-size patterns.

[0080] The stripe pattern was further tested using a step tester, and the test results are shown below. Figure 19 The test results show that the pattern thickness is approximately 1.9 μm.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified phenolic resin, characterized in that, The raw materials for preparation include: linear phenolic resin oligomers, phenolic substances containing reactive double bonds, and phenylphosphonic dichloride; The linear phenolic resin oligomer has the structure shown in general formula I: （Ⅰ）； Where n is an integer between 1 and 5.

2. The modified phenolic resin according to claim 1, characterized in that, The phenolic substances containing reactive double bonds include at least one of p-hydroxycinnamic acid, methyl p-hydroxycinnamate, 4-maleimide phenol, 4-(6-(acryloyloxy)hexyloxy)phenol, p-hydroxystyrene, hydroquinone monomethyl acrylate, and allyl phenolic resin.

3. The modified phenolic resin according to claim 1, characterized in that, The amounts of the linear phenolic resin oligomer and the phenolic substance containing reactive double bonds are both calculated based on the phenolic hydroxyl content. The molar amount of the phenolic substance containing reactive double bonds accounts for 1% to 30% of the total molar amount of the linear phenolic resin oligomer and the phenolic substance containing reactive double bonds, preferably 5% to 20%.

4. The modified phenolic resin according to claim 1, characterized in that, The ratio of the total molar number of the linear phenolic resin oligomer and the phenolic substances containing reactive double bonds to the molar number of phenylphosphonic dichloride is 1:(0.01~0.2), preferably 1:(0.05~0.15).

5. The method for preparing the modified phenolic resin according to any one of claims 1 to 4, characterized in that, The process includes the following steps: linear phenolic resin oligomers and phenolic substances containing reactive double bonds react with phenylphosphonic dichloride in a solvent under the action of an acid-binding agent.

6. The preparation method according to claim 5, characterized in that, The acid-binding agent includes triethylamine; Preferably, the molar ratio of the acid-binding agent to the phenylphosphonic dichloride is (2~3):

1.

7. The preparation method according to claim 5, characterized in that, The reaction temperature is 15~30℃, and the reaction time is 1~3 h.

8. A photoresist, characterized in that, Includes the modified phenolic resin according to any one of claims 1 to 4 or the modified phenolic resin prepared by the preparation method according to any one of claims 5 to 7; Preferably, the photoresist further includes a polyene compound, a photoinitiator, and a solvent; Preferably, the polyene compound includes at least one of pentaerythritol triacrylate and pentaerythritol tetraacrylate; Preferably, the solvent includes propylene glycol methyl ether acetate; Preferably, by weight, the photoresist comprises: 10-20 parts of modified phenolic resin, 25-35 parts of polyene compound, 2-6 parts of photoinitiator, and 40-60 parts of solvent.

9. The photoresist according to claim 8, characterized in that, It also includes quantum dots; Preferably, the quantum dots account for 20% to 30% of the mass of the photoresist.

10. A method for patterning photoresist, characterized in that, The process includes the following steps: placing the photoresist as described in claim 8 or 9 on a substrate, exposing it to ultraviolet light under the cover of a mask, and then developing it with a developer to obtain a pattern; Preferably, the developing solution comprises propylene glycol methyl ether acetate.

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