Positive photosensitive polyimide resin, photoresist and preparation method and application thereof

Abstract

The invention belongs to the technical field of electronic materials, and particularly discloses positive photosensitive polyimide resin, photoresist and a preparation method and application of the positive photosensitive polyimide resin and the photoresist. The positive photoresist is formed by mixing the positive photosensitive polyimide resin, diazonaphthoquinone sulfonate, a bridging agent and a solvent at room temperature; wherein the weight ratio of the positive photosensitive polyimide resin to the diazonaphthoquinone sulfonate to the bridging agent is 1: (5%-40%): (5%-20%), and the total solid content of each component in the solvent is 2%-30%. The positive photosensitive polyimide resin provided by the invention has a partial imidization hyperbranched structure, reduces intermolecular force, improves ultraviolet transmittance and photosensitive sensitivity, simultaneously improves solubility and fluidity (to ensure uniform coverage in coating), enhances thermal and chemical stability, is used in the fields of display, wafers, packaging and the like, and has wide application prospects. High-precision pattern transfer can be realized, the product resolution and reliability are improved, and the high-performance development of electronic devices is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic materials, and in particular relates to a positive photosensitive polyimide resin, a photoresist, and a preparation method and application thereof. Background Art

[0002] As an organic polymer material, polyimide has excellent mechanical and electrical properties, especially heat resistance. It can provide long-term stable service at 280°C. Some materials can even withstand high temperatures of up to 400°C. Polyimide with a special structure can even withstand extreme temperatures of 500°C. This characteristic led to its earliest widespread application in the military industry, mainly in the form of films and molding powders to assist in the manufacture of military equipment. In recent years, with the rapid development of science and technology and the increasing popularity of electronic products, polyimide materials have gradually entered the civilian market, and their scope of application has continued to expand. The application scenarios of the glue liquid form are also increasing. For example, photosensitive polyimide (PSPI) is an important application direction of polyimide in the field of photoresist, which has brought new technological breakthroughs to the manufacture of electronic devices.

[0003] As electronic devices continue to evolve toward miniaturization and higher performance, the application areas of photosensitive polyimides have expanded unprecedentedly. In the wafer and packaging sectors, their unique properties allow them to serve as a planarization layer for semiconductor devices, effectively improving the surface flatness of the device and ensuring the smooth progress of subsequent processes. They also act as a stress buffer, alleviating stress caused by differences in thermal expansion coefficients between different materials and improving the structural stability of the device. As an anti-ion etching layer, they provide excellent protection for the underlying material during the ion etching process, ensuring the accuracy of the etched pattern and improving the yield rate of chip manufacturing. Polyimides also play a vital role in the display industry. In addition to the widespread use of polyimide adhesives in liquid crystal alignment agents, photosensitive polyimides are also widely used as planarization layers and pixel segmentation layers. Through half-tone mask technology, they have successfully replaced traditional PS spacer materials, making a significant contribution to improving the performance of display panels.

[0004] Photosensitive polyimide can be divided into two types: positive and negative, depending on the difference in the image generated after exposure. During the exposure process of positive photosensitive polyimide, the part exposed to light is removed by the developer, while the part not exposed to light is retained, and the final pattern obtained is consistent with the mask. The imaging principle of negative photosensitive polyimide is the opposite. The part not exposed to light is removed by the developer, while the part exposed to light is retained, forming a pattern opposite to the mask. In the display field, positive photosensitive polyimide has become the mainstream choice in this field because its imaging characteristics are more in line with the manufacturing needs of display panels. With the continuous surge in the use of display panels in new energy vehicles, computers, mobile phones and other types of instruments and equipment, the market demand for positive photosensitive polyimide has increased sharply, attracting many material manufacturers to devote themselves to research and development and testing, and the market competition is becoming increasingly fierce. In this field, Japan's Toray, leveraging its early-mover advantage, currently leads in market share and quality stability. As early as the early 2000s, Toray established patents for positive photosensitive polyimide, widely applying its technology to key areas such as the planarization layer of TFT thin-film converters and the planarization and pixel segmentation layers of organic EL displays. Related invention patents include CN00800643.1, CN200610114895.7, and CN201680019104.4. In recent years, domestic companies and research institutions have also increased their R&D investment in photosensitive polyimide, resulting in the emergence of a large number of related patents, which has played a positive role in promoting my country's display industry.

[0005] However, the continuous advancement of display technology has also put forward more stringent requirements for materials used in the display industry. For positive photosensitive polyimide, the following problems existing in the existing technology need to be solved: First, in actual applications, improving photosensitivity often leads to a decrease in the film retention rate after development and curing. How to balance the conflicting performance indicators of high sensitivity and high film retention rate; Second, as a planarization layer, positive photosensitive polyimide needs to have higher leveling properties to ensure uniform coverage during the coating process to meet the increasingly sophisticated display panel manufacturing process requirements. The current traditional improvement methods are mostly focused on updating the bridging agent and photosensitizer in the formula, but practice has shown that the effect of this improvement method is very limited, and it is difficult to fundamentally meet the new material performance requirements of the rapid development of display technology. Therefore, the development of new positive photosensitive polyimide materials and preparation technologies is imminent.

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

[0007] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a positive photosensitive polyimide resin, a photoresist and a preparation method and application thereof, which are mainly used to solve the performance contradiction between high sensitivity and high film retention rate and insufficient leveling problem faced by positive photosensitive polyimide in practical applications.

[0008] The purpose of the present invention is to solve the problem through the following technical solutions:

[0009] In a first aspect, the present invention provides a positive photosensitive polyimide resin having a hyperbranched structure as shown in the following formula (1):

[0010]

[0011] In formula (1), Ar is For the anhydride of the group, the dotted line represents the site of attachment of the group to the oxygen atom;

[0012] R1 is an aromatic hexafluoroisopropyl group containing a hydroxyl group: The dashed line represents the site of attachment of the group to the nitrogen atom;

[0013] R2 is a hydrogen atom or a carboxyl group;

[0014] m and n are each independently an integer of 2 to 20.

[0015] Furthermore, Ar is a tribasic acid anhydride having a structure represented by the following formula (2) or the following formula (3):

[0016]

[0017]

[0018] Specifically, the synthesis route of the ternary acid anhydride having the structure shown in formula (2) is as follows:

[0019] 1) Using commercially available raw materials 1 and 4-chlorophthalic acid as raw materials at a molar ratio of 1:3, under nitrogen protection, adding solvent N,N-dimethylacetamide (DMAc) to achieve a solid content of 25% to 40%; then adding an excess of catalyst K2CO3, raising the temperature to 140°C, maintaining the temperature for 8 to 12 hours, and cooling to terminate the reaction; finally, slowly adding the solution dropwise to ice water, waiting for the ice to completely dissolve, acidifying the solution, and precipitating a large amount of light yellow solid, which was filtered and washed, and then dried in a vacuum oven at 60 to 80°C to obtain a hexacarboxylic acid with structure 2;

[0020] 2) A hexacarboxylic acid of structure 2 and a sufficient amount of acetic anhydride (generally, the weight ratio of the hexacarboxylic acid to acetic anhydride is 1:10 to 1:20, with acetic anhydride serving as a solvent and a dehydrating agent) are placed in a nitrogen-protected three-necked flask, heated and refluxed for 24 hours. When the solution is completely clear and transparent, the solution is slowly cooled to room temperature and allowed to stand for 10 to 12 hours, during which a large amount of milky white flaky crystals precipitate. The solution is filtered and dried to obtain a ternary acid anhydride monomer represented by the following formula (2).

[0021]

[0022] The synthesis route of the ternary acid anhydride of the structure shown in formula (3) is as follows:

[0023] 1) Commercially available raw materials 4 and 4-chlorophthalic acid are used as raw materials in a molar ratio of 1:3. Under nitrogen protection, a solvent DMAc is added to achieve a solid content of 25% to 40%; an excess amount of catalyst K2CO3 is then added, the temperature is raised to 150°C, the temperature is maintained for 8 to 12 hours, and the temperature is lowered to terminate the reaction; finally, the solution is slowly added dropwise to ice water, and after the ice is completely dissolved, the solution is acidified, a large amount of light yellow solid is precipitated, the solid is filtered and washed, and then dried in a vacuum oven at 60 to 80°C to obtain a hexacarboxylic acid with structure 5.

[0024] 2) A hexacarboxylic acid of structure 5 and a sufficient amount of acetic anhydride (generally, the weight ratio of the hexacarboxylic acid to acetic anhydride is 1:10 to 1:20, with acetic anhydride serving as a solvent and a dehydrating agent) are placed in a nitrogen-protected three-necked flask and heated under reflux for 24 hours. When the solution is completely clear and transparent, the solution is slowly cooled to room temperature and allowed to stand for 10 to 12 hours, during which a large amount of white flaky crystals precipitate. The solution is then filtered and dried to obtain a ternary acid anhydride monomer represented by the following formula (3).

[0025]

[0026] Furthermore, the R1 is a diamine having a structure represented by the following formula (4) or (5):

[0027]

[0028] Furthermore, the end-capping functional group where R2 is located is derived from an end-capping agent having a structure represented by the following formula (6) or the following formula (7):

[0029]

[0030] Furthermore, the imidization rate of the positive photosensitive polyimide resin is 20% to 80%.

[0031] Furthermore, the carboxyl groups of the non-imidized polyamic acid in the positive photosensitive polyimide resin are not limited to the m segment, the n segment or the R2 segment, and the ratio of the carboxyl groups to the imide ring is (2:8) to (8:2).

[0032] In a second aspect, the present invention further provides a method for preparing the positive photosensitive polyimide resin, the method comprising the following steps:

[0033] Step 1: Under nitrogen protection, reacting a hydroxyl-containing diamine with a tribasic acid anhydride in a solvent;

[0034] Step 2: Add a blocking agent and heat to 120°C to 155°C to partially imidize the solution. When the imidization rate reaches 20% to 80%, cool down and terminate the reaction;

[0035] Step 3: precipitating, stirring, filtering, washing and drying the obtained hyperbranched polymer solution to obtain a positive photosensitive polyimide resin with partial imidization hyperbranching.

[0036] Specifically, in step 1, the reaction is generally carried out at room temperature (if you want to speed up the reaction rate, the reaction temperature can be controlled at 40°C to 60°C), and the solid content of the total amount of the two reactants (hydroxydiamine and tribasic acid anhydride) in the solvent is maintained at 0.5% to 35%, mechanically stirred, and reacted for 5 to 12 hours before proceeding to the next step.

[0037] In step 2, a capping agent (phthalic anhydride or 4-carboxyphthalic anhydride) is added, and the molar ratio of hydroxydiamine, tribasic acid anhydride and capping agent is (5:3:2) to (2:1:1), and the reaction is continued for 5 to 12 hours; then, the temperature is raised to 120°C to 155°C to partially imidize the solution, and samples are taken every 20 minutes during the heating process. The imidization rate is characterized by infrared spectroscopy. When the imidization rate reaches 20% to 80%, preferably 30% to 70%, the reaction is terminated by cooling.

[0038] In step 3, the partially imidized polymer is precipitated into ultrapure water, stirred, filtered, washed with ethanol and dried to obtain a positive photosensitive polyimide resin with partially imidized hyperbranched structures.

[0039] In a third aspect, the present invention further provides a positive photoresist based on the positive photosensitive polyimide resin. The positive photoresist is formed by mixing the positive photosensitive polyimide resin with diazonaphthoquinone sulfonate, a bridging agent, and a solvent at room temperature.

[0040] Among them, the mass ratio of the photosensitive polyimide resin, diazonaphthoquinone sulfonate, bridging agent and solvent is (10:4:2) to (10:0.5:0.5); preferably (10:3:2) to (10:2:1), and the total solid content of each component in the positive photoresist in the solvent is 2% to 30%, preferably 5% to 15%.

[0041] Furthermore, the solvent is a mixture of one or more of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether, propylene glycol dimethyl ether and propylene glycol monomethyl ether acetate.

[0042] Specifically, the preparation process of the positive photoresist is as follows:

[0043] The partially imidized hyperbranched positive photosensitive polyimide resin is dissolved in a solvent. After complete dissolution, 5% to 20% of a commercially available phenolic bridging agent and 5% to 40% of a photosensitizer naphthoquinone sulfonate (PAC) are added. The total solid content of the resin, bridging agent, and PAC in the solvent is 2% to 30%, preferably 5% to 15%. The bridging agent can be a commercially available polyphenol compound, the main manufacturers of which are Asahi Organic Materials and Honshu Chemical. The photosensitizer naphthoquinone sulfonate (PAC) component is an o-azide naphthoquinone compound connected to a benzene ring carbon skeleton via a sulfonate group. Under ultraviolet light, the o-azide naphthoquinone is converted into enone and then into indanoic acid.

[0044] Furthermore, the PAC preferably has the following skeleton structure. These PACs can be used alone or in combination. The commercially available manufacturers are mainly Jiuri New Materials and Toyo Synthetics:

[0045]

[0046] Fourthly, the present invention also provides an application of the above-mentioned positive photoresist, which is used in the display, wafer, and packaging fields. Specifically, the positive photosensitive polyimide resin of the present application has high sensitivity and high leveling properties, is highly sensitive to ultraviolet light i-rays and mixed lines, and can be widely used in wafer manufacturing, OLED manufacturing, planarization layers, and pixel blocking layers.

[0047] Specifically, in the display field, the positive photoresist provided by the present invention can be used as a planarization layer for liquid crystal displays (LCDs) and organic light-emitting diode displays (OLEDs). With its high leveling and high sensitivity characteristics, it can be evenly spread during the coating process, effectively filling the subtle bumps on the substrate surface to form a flat, smooth film, significantly improving the flatness of the display panel, reducing light scattering and refraction caused by surface unevenness, and thus improving the clarity and uniformity of the display image, bringing users a better visual experience. In the production of the pixel segmentation layer, the positive photoresist can accurately define the pixel area, and its precise imaging capability during the exposure and development process can effectively prevent crosstalk between pixels, improve color contrast and image resolution, enhance the visual effect of display products, and help display technology develop in the direction of higher resolution and richer colors.

[0048] In the wafer and packaging fields, this positive photoresist also plays an important role. For example, in the wafer manufacturing process, as the core material of the photolithography process, it plays a decisive role in the accuracy of pattern transfer. Its high sensitivity makes the photolithography process more responsive to exposure energy. Combined with the good structural stability of the hyperbranched polyimide resin, it can ensure that the extremely fine circuit pattern on the mask is accurately copied to the photoresist layer on the wafer surface, meeting the stringent requirements of advanced processes for high-precision patterning and providing guarantees for the manufacture of high-performance, highly integrated chips. During the chip packaging stage, positive photoresist can serve as an insulating layer between the chip and the packaging substrate. With the excellent electrical properties of the polyimide material itself, it effectively prevents current leakage, ensures the stable transmission of electronic signals, and reduces signal interference and loss.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. The positive photosensitive polyimide resin provided by the present invention has a partially imidized hyperbranched structure. This structure greatly reduces the interaction between polyimide molecules, thereby significantly improving the ultraviolet transmittance, achieving a breakthrough in high sensitivity, and effectively solving the problem of decreased film retention when improving photosensitivity in the prior art. At the same time, the hyperbranched structure itself has good solubility and fluidity, giving the resin excellent leveling properties, meeting the strict requirements for high leveling as a flattening layer. The reason for having high sensitivity and high leveling is that the intermolecular interaction of polyimide with ordinary linear structure is relatively strong, and the ultraviolet transmittance is not high, which is not conducive to the absorption of exposure light source by photosensitizer. The multi-branched structure of the hyperbranched structure destroys the CT between imine molecules, so it is conducive to improving sensitivity; at the same time, the hyperbranched structure has no intermolecular interaction, which is conducive to solubility and fluidity. In addition, the characteristics of partial imidization optimize the thermal stability and chemical stability of the resin, and it can still maintain stable performance under high temperature and complex chemical environments, broadening its application range in different scenarios.

[0051] 2. The method for preparing a positive photosensitive polyimide resin provided by the present invention has mild and easy-to-control reaction conditions. The reaction is carried out under nitrogen protection. The reaction temperature, time, and material ratio of each step have clear and reasonable setting ranges, which makes the preparation process highly repeatable and stable, is conducive to large-scale industrial production, and can effectively reduce production costs and improve production efficiency.

[0052] 3. The present invention utilizes a positive photoresist synthesized from a positive photosensitive polyimide resin. By precisely adjusting the ratios of resin, diazonaphthoquinone sulfonate, bridging agent, and specific solvent, and rationally controlling the total solids content, the photoresist ensures excellent coating performance while meeting the diverse performance requirements of different application scenarios. In the display field, when used in the manufacture of display panels, it can achieve high-precision pattern transfer, improve pixel resolution and clarity, and enhance the quality of displayed images. In the wafer and packaging fields, it can accurately replicate mask patterns during chip manufacturing and packaging, ensuring chip manufacturing accuracy and yield, and enhancing chip performance and reliability. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the invention. In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work. Figure 1 Schematic diagram of the test of the leveling performance of the present invention. DETAILED DESCRIPTION

[0053] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention described in detail in the appended claims.

[0054] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with relevant experiments.

[0055] The imidization rate in this invention refers to the conversion of the polyamic acid groups generated after the first polymerization reaction into imide rings through the second high-temperature imidization reaction. This refers to the ratio of imide rings generated in the second reaction to the polyamic acid groups generated in the first reaction. Specific characterization methods are described in infrared spectroscopy.

[0056] Preparation Example 1 (Preparation of a tribasic acid anhydride having the structure shown in formula (2))

[0057] The specific preparation process of the ternary acid anhydride of the structure shown in formula (2) of the present invention is as follows:

[0058] 1) In a dry, clean, nitrogen-filled three-necked flask, add 30.6 g (100 mmol) of commercially available raw material 1 and 60.18 g (300 mmol) of 4-chlorophthalic acid, then add 230 ml of solvent DMAc. After complete dissolution, add 48.3 g of catalyst K2CO3, raise the temperature to 140°C, maintain the temperature for 8 hours, terminate the reaction, and cool to room temperature; finally, slowly pour the reaction solution into 1500 ml of ice water, stir, and acidify to neutrality. There is a large amount of shallow A yellow solid precipitated, which was repeatedly washed with water and filtered; then dried in a vacuum oven at 60-80°C to obtain 62.4 g of a hexacarboxylic acid having the structure 2 (yield 78%, NMR: 11.80 ppm, 6H, COOH, s; 8.30 ppm, 3H, CH, d; 8.06 ppm, 3H, CH, s; 7.47 ppm, 3H, CH, d; 7.12 ppm, 6H, CH, d; 6.87 ppm, H, CH, d; 1.98 ppm, 3H, CH3, s).

[0059] 2) In a nitrogen-protected three-necked flask, 39.9 g (50 mmol) of a hexacarboxylic acid of structure 2 and 200 ml of acetic anhydride were added and heated under reflux for 24 hours. After the solution became completely clear and transparent, the temperature was slowly lowered to room temperature and allowed to stand for 12 hours, during which a large amount of milky white flaky crystals precipitated. The mixture was filtered and dried to obtain 29.8 g of a ternary anhydride having the structure represented by the following formula (2) (yield 80%, NMR: 8.28 ppm, 3H, CH, d; 8.12 ppm, 3H, CH, s; 7.42 ppm, 3H, CH, d; 7.23 ppm, 6H, CH, d; 6.86 ppm, 6H, CH, d; 1.98 ppm, 3H, CH3, s).

[0060]

[0061] Preparation Example 2 (Preparation of a tribasic acid anhydride having the structure shown in formula (3))

[0062] The specific preparation process of the ternary acid anhydride of the structure shown in formula (3) of the present invention is as follows:

[0063] 1) In a dry, clean, nitrogen-filled three-necked flask, 42.5 g (100 mmol) of commercially available raw material 4 and 60.18 g (300 mmol) of 4-chlorophthalic acid were added, followed by 280 ml of DMAc solvent. After complete dissolution, 48.3 g of catalyst K2CO3 was added, and the temperature was raised to 150°C and maintained for 10 hours. The reaction was terminated and the temperature was cooled to room temperature. The reaction solution was slowly poured into 1500 ml of ice water, stirred, and acidified to neutrality. A large amount of light yellow solid precipitated, which was repeatedly washed with water and filtered; and dried in a vacuum oven at 80° C. to obtain 67.7 g of a hexacarboxylic acid with structure 2 (yield 73.8%, NMR: 11.76 ppm, 6H, COOH, s; 8.36 ppm, 3H, CH, d; 8.04 ppm, 3H, CH, s; 7.42 ppm, 3H, CH, d; 7.02-7.10 ppm, 10H, CH, m; 6.83-6.84 ppm, 6H, CH, d; 1.98 ppm, 3H, CH 3 , s; 1.59 ppm, 6H, CH 3 , s).

[0064] 2) In a nitrogen-protected three-necked flask, 45.8 g (50 mmol) of a hexacarboxylic acid of structure 5 and 200 ml of acetic anhydride were added, and the mixture was heated under reflux for 24 hours. After the solution became completely clear and transparent, the mixture was slowly cooled to room temperature and allowed to stand for 12 hours, during which a large amount of white flaky crystals precipitated. The mixture was filtered and dried to obtain 25.4 g of a ternary anhydride 6 having the structure represented by the following formula (3) (yield 58.9%, NMR: 8.34 ppm, 3H, CH, d; 8.08 ppm, 3H, CH, s; 7.46 ppm, 3H, CH, d; 7.03-7.10 ppm, 10H, CH, m; 6.83-6.84 ppm, 6H, CH, d; 1.98 ppm, 3H, CH3, s; 1.59 ppm, 6H, CH3, s).

[0065]

[0066] Example 1 (monomer 2:1:1)

[0067] The specific preparation process of a positive photosensitive polyimide resin provided in an embodiment of the present invention is as follows:

[0068] 1) In a clean, dry, mechanically stirred reactor purged with nitrogen, 7.32 g (20 mmol) of 6FAP hydroxyl-containing diamine (2,2-bis[3-(4-(amino)amido-4-hydroxyphenyl]hexafluoropropane) and 160 ml of NMP were added. After complete dissolution, 7.45 g (10 mmol) of the tribasic anhydride prepared in Preparation Example 1 was slowly added in batches. The mixture was reacted at room temperature for 2 hours, then heated at 50°C for 3 hours, and then cooled to room temperature.

[0069] 2) Add 1.08 g (10 mmol) of phthalic anhydride and react at room temperature for 5 hours. Then raise the temperature to 145° C. and maintain for 60 minutes (when the imidization rate is detected to be 67.5%) to stop the reaction.

[0070] 3) Finally, the partially imidized polymer was precipitated into ultrapure water, stirred, filtered, washed with ethanol, and then dried in a vacuum oven at 50° C. for 72 hours to obtain a positive photosensitive polyimide resin with partially imidized hyperbranched structure.

[0071] The embodiment of the present invention further provides a positive photoresist based on the above-mentioned positive photosensitive polyimide resin 1. The preparation process of the positive photoresist is as follows:

[0072] 10 g of the aforementioned positive photosensitive polyimide resin having partial imidization and hyperbranching was weighed and dissolved in 90 g of γ-butyrolactone (GBL). After complete dissolution, 0.5 g of a commercially available bridging agent MW-390 (commercial brand) from Sanhe Chemical and 2 g of a commercially available diazonaphthoquinone sulfonate (PAC) photosensitizer 4NT-300 from Toyo Gosei were added. After complete dissolution, the mixture was filtered through a 0.48 μm PTFE pinhole filter to obtain a positive photoresist.

[0073] Example 2 (monomer 2:1:1)

[0074] The specific preparation process of a positive photosensitive polyimide resin provided in an embodiment of the present invention is as follows:

[0075] 1) Add 12.09 g (20 mmol) of hydroxylamide diamine (2,2-bis[3-(4-(amino)amido-4-hydroxyphenyl]hexafluoropropane) and 180 ml of NMP solvent. After complete dissolution, slowly add 8.62 g (10 mmol) of the tribasic acid anhydride prepared in Preparation Example 2 in batches. React at room temperature for 2 hours, heat at 50°C for 3 hours, and then cool to room temperature.

[0076] 2) Add 1.92 g (10 mmol) of phthalic anhydride and react at room temperature for 5 hours. Raise the temperature to 135°C and maintain for 40 minutes (when the imidization rate is detected to be 58.7%), then stop the reaction.

[0077] 3) Finally, the partially imidized polymer was precipitated into ultrapure water, stirred, filtered, washed with ethanol, and then dried in a vacuum oven at 60° C. for 72 hours to obtain a positive photosensitive polyimide resin II having partially imidized hyperbranched structures.

[0078] The embodiment of the present invention further provides a positive photoresist based on the above-mentioned positive photosensitive polyimide resin II. The preparation process of the positive photoresist is as follows:

[0079] 10 g of the above-mentioned positive photosensitive polyimide resin II with partial imidization hyperbranching was weighed and dissolved in 90 g of propylene glycol monomethyl ether (PGME). After complete dissolution, 1.5 g of Honshu Chemical's commercially available bridging agent trisp-HAP (commercial brand) and 3.0 g of Toyo Gosei's commercially available o-naphthoquinone azide (PAC) photosensitizer HP-190 were added. After complete dissolution, the mixture was filtered through a 0.48 μm PTFE pinhole filter to obtain a positive photoresist II.

[0080] Example 3 (monomer 5:3:1)

[0081] The specific preparation process of a positive photosensitive polyimide resin provided in an embodiment of the present invention is as follows:

[0082] 1) In a clean, dry, mechanically stirred reactor purged with nitrogen, 18.3 g (50 mmol) of 6FAP-containing hydroxyl diamine and 550 ml of NMP were added. After complete dissolution, 22.35 g (30 mmol) of the tribasic anhydride prepared in Preparation Example 1 was slowly added in batches. The mixture was reacted at room temperature for 2 hours, then heated at 50°C for 3 hours, and then cooled to room temperature.

[0083] 2) Add 1.08 g (10 mmol) of phthalic anhydride and react at room temperature for 5 hours. Then raise the temperature to 145° C. and maintain for 30 minutes (when the imidization rate is detected to be 48.9%) to stop the reaction.

[0084] 3) Finally, the partially imidized polymer was precipitated into ultrapure water, stirred, filtered, washed with ethanol, and then dried in a vacuum oven at 50° C. for 72 hours to obtain a positive photosensitive polyimide resin III having partially imidized hyperbranched structure.

[0085] The embodiment of the present invention further provides a positive photoresist based on the above-mentioned positive photosensitive polyimide resin three. The preparation process of the positive photoresist is as follows:

[0086] 10 g of the above-mentioned positive photosensitive polyimide resin III with partial imidization hyperbranching was weighed and dissolved in a mixed solvent of 70 g of propylene glycol monomethyl ether (PGME) and 20 g of γ-butyrolactone (GBL). After complete dissolution, 2.0 g of Honshu Chemical's commercially available bridging agent trisp-HAP (commercial brand) and 2.5 g of Toyo Gosei's commercially available o-azide naphthoquinone diazonium naphthoquinone sulfonate (PAC) photosensitizer HP-170 were added. After complete dissolution, the mixture was filtered through a 0.48 μm PTFE pinhole filter to obtain positive photoresist III.

[0087] Example 4 (monomer 5:3:1)

[0088] The specific preparation process of a positive photosensitive polyimide resin provided in an embodiment of the present invention is as follows:

[0089] 1) Add 30.23 g (50 mmol) of hydroxylamide diamine and 540 ml of NMP solvent. After complete dissolution, slowly add 25.86 g (30 mmol) of the tribasic acid anhydride prepared in Preparation Example 2 in batches. React at room temperature for 2 hours, heat at 50°C for 3 hours, and then cool to room temperature.

[0090] 2) Add 1.92 g (10 mmol) of phthalic anhydride and react at room temperature for 5 hours. Raise the temperature to 125°C and maintain for 40 minutes (when the imidization rate is detected to be 42.6%), then stop the reaction.

[0091] 3) Finally, the partially imidized polymer was precipitated into ultrapure water, stirred, filtered, washed with ethanol, and then dried in a vacuum oven at 60° C. for 72 hours to obtain a positive photosensitive polyimide resin 4 having partially imidized hyperbranched structures.

[0092] The embodiment of the present invention further provides a positive photoresist based on the above-mentioned positive photosensitive polyimide resin 4. The preparation process of the positive photoresist is as follows:

[0093] 10 g of the above-mentioned positive photosensitive polyimide resin 4 having partial imidization hyperbranching was weighed and dissolved in a mixed solvent of 70 g of propylene glycol monomethyl ether (PGME) and 20 g of γ-butyrolactone (GBL) until completely dissolved; 1.0 g of Sanhe Chemical commercially available bridging agent MW-390 (commercial brand) and 3.0 g of Toyo Gosei commercially available o-naphthoquinone azide (PAC) photosensitizer HP-190 were added, and after complete dissolution, the mixture was filtered through a 0.48 μm PTFE pinhole filter to obtain a positive photoresist 4.

[0094] Example 5 (monomer 9:5:3)

[0095] The specific preparation process of a positive photosensitive polyimide resin provided in an embodiment of the present invention is as follows:

[0096] 1) In a clean, dry, mechanically stirred reactor purged with nitrogen, 16.47 g (45 mmol) of 6FAP-containing hydroxyl diamine and 450 ml of NMP were added. After complete dissolution, 18.63 g (25 mmol) of the tribasic anhydride prepared in Preparation Example 1 was slowly added in batches. The mixture was reacted at room temperature for 2 hours, then heated at 50°C for 3 hours, and then cooled to room temperature.

[0097] 2) Add 2.88 g (15 mmol) of trimellitic anhydride and react at room temperature for 5 hours. Then raise the temperature to 145° C. and maintain for 60 minutes (when the imidization rate is detected to be 69.7%) to stop the reaction.

[0098] 3) Finally, the partially imidized polymer was precipitated into ultrapure water, stirred, filtered, washed with ethanol, and then dried in a vacuum oven at 50° C. for 72 hours to obtain a positive photosensitive polyimide resin 5 having partially imidized hyperbranched structures.

[0099] The embodiment of the present invention further provides a positive photoresist based on the positive photosensitive polyimide resin V. The preparation process of the positive photoresist is as follows:

[0100] Weigh 10 g of the above-mentioned positive photosensitive polyimide resin 5 with partial imidization hyperbranching and dissolve it in a mixed solvent of 80 g of propylene glycol monomethyl ether (PGME) and 10 g of γ-butyrolactone (GBL) until it is completely dissolved; then add 1.0 g of Honshu Chemical's commercially available bridging agent bisp-AP (commercial brand) and 2.5 g of Jiuri New Materials' commercially available o-azide naphthoquinone diazonium naphthoquinone sulfonate (PAC) photosensitizer 5430. After they are completely dissolved, filter through a 0.48 μm PTFE pinhole filter to obtain a positive photoresist 5.

[0101] Example 6 (monomer 9:5:3)

[0102] The specific preparation process of a positive photosensitive polyimide resin provided in an embodiment of the present invention is as follows:

[0103] 1) Add 27.21 g (45 mmol) of hydroxylamide diamine and 490 ml of NMP solvent. After complete dissolution, slowly add 21.55 g (30 mmol) of the tribasic acid anhydride prepared in Preparation Example 2 in batches. React at room temperature for 2 hours, heat at 50°C for 3 hours, and then cool to room temperature.

[0104] 2) Add 2.88 g (15 mmol) of trimellitic anhydride and react at room temperature for 5 hours. Raise the temperature to 130°C and maintain for 70 minutes (when the imidization rate is detected to be 69.6%), then stop the reaction.

[0105] 3) Finally, the partially imidized polymer was precipitated into ultrapure water, stirred, filtered, washed with ethanol, and then dried in a vacuum oven at 60° C. for 72 hours to obtain a positive photosensitive polyimide resin VI having partially imidized hyperbranched structures.

[0106] The embodiment of the present invention further provides a positive photoresist based on the positive photosensitive polyimide resin VI. The preparation process of the positive photoresist is as follows:

[0107] Weigh 10 g of the above-mentioned positive photosensitive polyimide resin with partial imidization hyperbranching and dissolve it in a mixed solvent of 70 g of propylene glycol monomethyl ether (PGME) and 30 g of γ-butyrolactone (GBL) until it is completely dissolved; then add 1.5 g of Sanhe Chemical commercially available bridging agent MW-390 (commercial brand) and 2.0 g of Jiuri New Materials commercially available o-azide naphthoquinone diazonium naphthoquinone sulfonate (PAC) photosensitizer 5430. After they are completely dissolved, filter through a 0.48 μm PTFE pinhole filter to obtain positive photoresist 6.

[0108] Comparative Example 1

[0109] 20.0 g of 4,4'-diaminodiphenyl ether (100 mmol) was dissolved in 300 ml of NMP solvent. After complete dissolution, 19.62 g of pyromellitic anhydride (90 mmol) was added. After stirring and polymerization at room temperature for 2 hours, 1.08 g of phthalic anhydride (10 mmol) was added and the reaction was continued for 4 hours. The temperature was raised to 125°C and maintained for 40 minutes. The imidization rate was 40.7% by infrared detection. The product was precipitated into ultrapure water, filtered and washed, and dried in a vacuum oven at 50°C for 72 hours to obtain comparative resin 1.

[0110] Weigh 10 g of the above-mentioned comparative resin 6 and dissolve it in a mixed solvent of 70 g of propylene glycol monomethyl ether (PGME) and 30 g of γ-butyrolactone (GBL) until it is completely dissolved; then add 1.5 g of Sanhe Chemical commercially available bridging agent MW-390 (commercial brand) and 2.0 g of Jiuri New Materials commercially available o-azide naphthoquinone diazonium naphthoquinone sulfonate (PAC) photosensitizer 5430, and after they are completely dissolved, filter through a 0.48 μm PTFE pinhole filter to obtain comparative photoresist 1.

[0111] Comparative Example 2

[0112] 20.0 g of 4,4'-diaminodiphenyl ether (100 mmol) was dissolved in 370 ml of NMP solvent. After complete dissolution, 39.96 g of 4,4'-(hexafluoroisopropylene) diphthalic anhydride (90 mmol) was added. After stirring and polymerization at room temperature for 4 hours, 1.08 g of phthalic anhydride (10 mmol) was added and the reaction was continued for 4 hours. The temperature was raised to 145°C and maintained for 50 minutes. The imidization rate was 63.5% by infrared detection. The product was precipitated into ultrapure water, filtered and washed, and dried in a vacuum oven at 50°C for 72 hours to obtain comparative resin II.

[0113] 10 g of the comparative resin II was weighed and dissolved in 90 g of γ-butyrolactone (GBL) until completely dissolved. 0.5 g of Sanhe Chemical's commercially available bridging agent MW-390 (commercial brand) and 2 g of Toyo Gosei's commercially available naphthoquinone sulfonate (PAC) photosensitizer 4NT-300 were then added. After complete dissolution, the mixture was filtered through a 0.48 μm PTFE pinhole filter to obtain a comparative positive photoresist II.

[0114] Comparative Example 3

[0115] 36.6 g of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (100 mmol) was dissolved in 420 ml of NMP solvent. After complete dissolution, 39.96 g of 4,4'-(hexafluoroisopropylene)diphthalic anhydride (90 mmol) was added. After stirring and polymerization at room temperature for 4 hours, 1.08 g of phthalic anhydride (10 mmol) was added and the reaction was continued for 4 hours. The temperature was raised to 135°C and maintained for 50 minutes. The imidization rate was 60.5% by infrared detection. The product was precipitated into ultrapure water, filtered and washed, and dried in a vacuum oven at 50°C for 72 hours to obtain comparative resin three.

[0116] Weigh 10 g of the above-mentioned comparative resin three and dissolve it in a mixed solvent of 80 g of propylene glycol monomethyl ether (PGME) and 10 g of γ-butyrolactone (GBL) until it is completely dissolved; then add 1.0 g of Honshu Chemical's commercially available bridging agent bisp-AP (commercial brand) and 2.5 g of Jiuri New Materials' commercially available o-azide naphthoquinone diazonium naphthoquinone sulfonate (PAC) photosensitizer 5430. After complete dissolution, filter through a 0.48 μm PTFE pinhole filter to obtain comparative positive photoresist three.

[0117] Comparative Example 4

[0118] 60.45 g of 2,2-bis[3-(4-(amino)amido-4-hydroxyphenyl]hexafluoropropane (100 mmol) was dissolved in 580 ml of NMP solvent. After complete dissolution, 39.96 g of 4,4'-(hexafluoroisopropylene)diphthalic anhydride (90 mmol) was added. After stirring and polymerization at room temperature for 4 hours, 1.08 g of phthalic anhydride (10 mmol) was added and the reaction was continued for 4 hours. The temperature was raised to 145°C and maintained for 50 minutes. The imidization rate was 66.6% by infrared detection. The product was precipitated into ultrapure water, filtered and washed, and dried in a vacuum oven at 50°C for 72 hours to obtain comparative resin 4.

[0119] Weigh 10 g of the above-mentioned comparative resin 4 and dissolve it in a mixed solvent of 80 g of propylene glycol monomethyl ether (PGME) and 10 g of γ-butyrolactone (GBL) until it is completely dissolved; then add 1.0 g of Honshu Chemical's commercially available bridging agent bisp-AP (commercial brand) and 2.5 g of Jiuri New Materials' commercially available o-azide naphthoquinone diazonium naphthoquinone sulfonate (PAC) photosensitizer 5430. After complete dissolution, filter through a 0.48 μm PTFE pinhole filter to obtain comparative positive photoresist 4.

[0120] In order to verify the efficacy of the present invention, the applicant conducted performance tests on the positive photoresists prepared in Examples 1 to 6 and Comparative Examples 1 to 4. Specifically, the performance tests included the following aspects:

[0121] 1. Infrared spectroscopy (FT-IR) was performed using a German Bruker infrared spectrometer, model INVENIO, using powder absorption method. -1 The stretching vibration peak of the CH of the imine ring at 1510 cm -1 First, prepare a standard sample with an imidization rate of 100%: select a hyperbranched resin sample with the same structure and powder of any imidization rate, place it in a high nitrogen oven at 300℃ for 1 hour, and then heat imidize it at 1380cm -1 The stretching vibration peak of the CH of the imine ring at 1510 cm -1 The ratio of the benzene ring skeleton peak at 1380 cm is considered to be the ratio of 100% imidization of the hyperbranched polyimide resin. Based on this value, the infrared spectroscopy of the resin powder obtained in other examples is 1380 cm -1 The stretching vibration peak of the CH of the imine ring at 1510 cm -1 The ratio of the benzene ring skeleton peak at the bottom of the column to the bottom of the column is compared with the reference value and is taken as the imidization rate of the resin powder in the example.

[0122] 2. Viscosity test: Brookfield rotational viscometer DV3-TLV, constant temperature test at 23°C.

[0123] 3. Exposure Sensitivity Testing: The positive-tone polyimide photoresist prepared in Example 1 was spin-coated onto a clean, dry glass slide at 100–200 rpm for 20 seconds, followed by baking on a 120°C hot plate for 120 seconds to obtain a film with a thickness of 1.5–2 μm. Subsequently, the film was exposed using an ABM contact lithography system with an exposure energy range of 20–200 mj / cm². A 2.38% TMAH developer was then sprayed on the developer for 20–60 seconds, rinsed with ultrapure water, and dried before the pattern was evaluated under a microscope.

[0124] 3. Exposure sensitivity test: The positive polyimide photoresist prepared in the example was spin-coated on a clean and dry glass sheet at 100-200 rpm for 20 seconds, and then baked on a 120°C hot plate for 120 seconds to obtain a film with a thickness of 1.5-2 μm. Subsequently, the film was exposed using an ABM contact exposure machine with an exposure energy of 20-200 mj / cm 2 , then use 2.38% TMAH developer, spray on the developer for 20-60s, rinse with ultrapure water, blow dry and evaluate the pattern under a microscope.

[0125] The photosensitivity (sensitivity) is the minimum exposure amount to achieve a 10μm line consistent with the mask, which is recorded as sensitivity; the film retention rate is the change in thickness before and after exposure and development at the 10μm line under the sensitivity exposure measurement, and the ratio of the thickness of the line after exposure and development to the thickness before exposure and development is recorded as the film retention rate.

[0126] 4. Thickness test: step profiler test, model: Bruker Dektak XT.

[0127] 5. Leveling performance test: Single line boss: boss height 0.8μm, boss width 10μm, positive PSPI thickness 2μm; leveling DOP is Figure 1 The calculation formula is obtained.

[0128] 6. UV transmittance and yellowing index Y value testing: UV-visible near-infrared spectrophotometer, model: Shimadzu UV2600i. For thin film sample testing, for thin films on glass plates, a glass substrate of the same thickness should be tested before the sample. The blank glass plate should be subtracted when testing the sample.

[0129] The final test results are shown in Table 1 below:

[0130] Table 1 Test results of positive photoresists prepared in Examples 1 to 6 and Comparative Examples 1 to 4

[0131]

[0132]

[0133] The test results in Table 1 show that the positive photoresists prepared in Examples 1 to 6 of the present invention have a lower and more stable viscosity than the linear resin of the comparative example, due to the design of the hyperbranched structure of the polyimide resin, under the premise of matching the mainstream bridging agent, photosensitizer and solvent in the market; the spin coating process is controlled to obtain films of similar thickness. Due to the hyperbranched structure, the interaction between the polyimide resins is very weak, which can greatly increase the transmittance of ultraviolet light. The average ultraviolet transmittance in the entire range of 380nm to 800nm ​​is very high, even reaching more than 98%. This is very beneficial for use as the main resin of the photoresist, improving the utilization rate of the ultraviolet light of the exposure light source, especially for high-sensitivity positive polyimide photoresists. Through the sensitivity test of exposure and development, it is indeed confirmed that the hyperbranched structure resin greatly improves the sensitivity of the photoresist compared with the linear structure resin.

[0134] The present invention also has the advantages that the photoresist of the present invention has the advantages of high leveling performance, high surface roughness, and good solubility.In addition, interaction force is little between the hyperbranched polyimide resin molecule, and solvent is easy to penetrate, and has good solubility.The exposed area is easier to be dissolved in the developer TMAH, and the non-exposed area has diazonaphthoquinone sulfonic acid ester to suppress dissolving, and therefore, as the photoresist main resin contrast height, the film retention rate is high after development.Simultaneously, due to the hyperbranched special structure, the molecular chain is easy to slip and rolls, so leveling performance is obviously better than the linear resin that the comparative example adopts, greatly improves the value of leveling performance DOP, the present embodiment leveling performance is all greater than 80%, and the comparative example leveling performance is the highest only 71.6%.That is to say, positive photoresist provided by the invention possesses higher leveling performance, to guarantee that in coating process, can evenly cover, thereby meets day by day meticulous display panel manufacturing process requirement.

[0135] Comparative Examples 1 to 4 all use linear polyimide resins without introducing hyperbranched structures. The specific analysis is as follows:

[0136] Comparative Example 1: A common diamine (4,4'-diaminodiphenyl ether) reacts with pyromellitic anhydride to form linear molecular chains. The resulting positive photoresist has a UV transmittance of only 74.32%. Strong intermolecular forces lead to insufficient light absorption, making it impossible to complete exposure and development, resulting in a poorly formed pattern. This is because the linear structure lacks branching, the molecules are tightly packed, making it difficult for UV light to penetrate, and the photosensitivity is extremely low.

[0137] Comparative Example 2: Using a diamine containing hexafluoroisopropyl (4,4'-(hexafluoroisopropylene) diphthalic anhydride), but still with a linear structure. The resulting positive photoresist has a sensitivity of 160mJ / cm 2 (higher than the example), the film retention rate is 63.2%, and the leveling DOP is only 55.7%. The reason is that although the hexafluoro group improves solubility, the linear molecular chains still have strong interactions, the UV transmittance and leveling properties are limited, and the photosensitivity is low.

[0138] Comparative Example 3: Using a hydroxyl-containing diamine (2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane) and hexafluorodiphthalic anhydride, the linear structure contains hydroxyl groups. The resulting positive photoresist has a UV transmittance of 95.17% and a sensitivity of 120 mJ / cm 2 The film retention rate is 74.8%, and the leveling DOP is 68.9%. The reason is that the introduction of hydroxyl groups increases polarity and strengthens the hydrogen bonding between molecules, resulting in an increase in viscosity (10.18 cps). However, the leveling and photosensitivity are still lower than those of the hyperbranched structure.

[0139] Comparative Example 4: A linear resin containing hydroxyamide diamine and hexafluorodiphthalic anhydride, with an amide group in the molecular chain. The resulting positive photoresist has a UV transmittance of 95.03% and a sensitivity of 110 mJ / cm 2 The film retention rate is 76.6%, and the leveling DOP is 71.6%. The reason is that the amide group further strengthens the intermolecular force. Although the film retention rate is slightly improved, the viscosity increases significantly (12.46cps), and the leveling and sensitivity still do not break through the bottleneck of the linear structure.

[0140] That is, due to the inherent defects of the linear molecular chain (strong intermolecular forces, low UV transmittance, and poor fluidity), Comparative Examples 1 to 4 cannot achieve high sensitivity, high film retention, and leveling properties at the same time, and the yellowing index YI values ​​(all greater than 26%) are much greater than the YI values ​​in the examples. This indicates that the photoresists in the comparative examples are inferior to those in the examples in terms of weather resistance, thermal stability, and optical transparency. The hyperbranched structure of the present invention, by destroying intermolecular forces and improving UV transmittance and fluidity, significantly improves weather resistance, thermal stability, and optical transparency, thereby fundamentally resolving the performance contradictions of traditional positive photosensitive polyimides.

[0141] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0142] It should be understood that the present invention is not limited to the above description and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A positive photosensitive polyimide resin, characterized in that: The positive photosensitive polyimide resin has a hyperbranched structure as shown in the following formula (1): In formula (1), Ar is For the anhydride of the group, the dotted line represents the site of attachment of the group to the oxygen atom; R1 is an aromatic hexafluoroisopropyl group containing a hydroxyl group: The dashed line represents the site of attachment of the group to the nitrogen atom; R2 is a hydrogen atom or a carboxyl group; m and n are each independently an integer of 2 to 20.

2. The positive photosensitive polyimide resin according to claim 1, characterized in that Ar is a tribasic acid anhydride having a structure shown in the following formula (2) or the following formula (3):

3. The positive photosensitive polyimide resin according to claim 1, characterized in that The R1 is a diamine having a structure shown in the following formula (4) or the following formula (5):

4. The positive photosensitive polyimide resin according to claim 1, characterized in that The end-blocking functional group where R2 is located is derived from an end-blocking agent having a structure shown in the following formula (6) or the following formula (7):

5. The positive photosensitive polyimide resin according to claim 1, characterized in that The imidization rate of the positive photosensitive polyimide resin is 20% to 80%.

6. A method for preparing a positive photosensitive polyimide resin according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Step 1: Under nitrogen protection, reacting a hydroxyl-containing diamine with a tribasic acid anhydride in a solvent; Step 2: Add a blocking agent and heat to 120°C to 155°C to partially imidize the solution. When the imidization rate reaches 20% to 80%, cool down and terminate the reaction; Step 3: precipitate, stir, filter, wash and dry the partially imidized polymer obtained in step 2 to obtain a positive photosensitive polyimide resin with partially imidized hyperbranched structures.

7. The method for preparing a positive photosensitive polyimide resin according to claim 6, wherein: In step 1, the solid content of the hydroxydiamine and tribasic acid anhydride in the solvent is 0.5% to 35%.

8. The method for preparing a positive photosensitive polyimide resin according to claim 6, wherein: In the preparation method, the molar ratio of hydroxydiamine, tribasic acid anhydride and end-capping agent is (5:3:2) to (2:1:1).

9. A positive photoresist, characterized in that The positive photoresist is formed by mixing the positive photosensitive polyimide resin according to any one of claims 1 to 5, naphthoquinone diazide sulfonate, a bridging agent and a solvent at room temperature; The mass ratio of the photosensitive polyimide resin, diazonaphthoquinone sulfonate, bridging agent and solvent is (10:4:2) to (10:0.5:0.5), and the total solid content of each component in the positive photoresist in the solvent is 2% to 30%.

10. A use of the positive photoresist according to claim 9, characterized in that: The positive photoresist is used in the display field, wafer and packaging field.

Images