Photosensitive polyimide precursor, method for producing the same, photosensitive polyimide paste, and photosensitive polyimide

Abstract

The application discloses a photosensitive polyimide precursor and a preparation method thereof, a photosensitive polyimide paste and a photosensitive polyimide, and belongs to the technical field of photosensitive polyimide materials. The photosensitive polyimide precursor has the structure shown in the following chemical formula 1. Compared with the prior art, the application mainly introduces siloxane, nitrogen-containing heterocyclic groups and photosensitive groups on the main chain of the photosensitive polyimide precursor. Therefore, the chemical bonding strength of the photosensitive polyimide material and the metal interface can be enhanced, the interface adhesion and the thermal stress release capacity of the photosensitive polyimide material and the conductive metal layer can be realized, the interface characteristics of the photosensitive polyimide material and the conductive metal material are better, and the defects of the prior art are compensated.

Description

Technical Field

[0001] This application relates to the field of photosensitive polyimide materials technology, specifically to a photosensitive polyimide precursor and its preparation method, a photosensitive polyimide slurry, and a photosensitive polyimide. Background Technology

[0002] As semiconductor processes advance to 5nm and below, advanced packaging and back-end interconnects place higher demands on high-density redistribution layers (RDLs). Photosensitive polyimide (PSPI) is widely used as both the dielectric layer and stress buffer layer in RDLs due to its excellent dielectric properties, thermomechanical stability, and direct photolithography patterning capabilities. However, the matching of the coefficients of thermal expansion between existing photosensitive polyimide materials and conductive metal interfaces needs further improvement.

[0003] It should be noted that the above statements are only used to provide background information related to this application and do not necessarily constitute prior art. Summary of the Invention

[0004] In a first aspect of this application, a photosensitive polyimide precursor is provided, having the structure shown in Chemical Formula 1 below: Chemical formula 1: ; X and Y each independently include a tetravalent aromatic group; Z is a first-class divalent group containing siloxane functional groups; W represents a type II divalent group containing a heterocyclic structure; R includes hydrogen and a monovalent organic group containing a photosensitive group, wherein the photosensitive group contains a carbon-carbon unsaturated double bond; The value of n ranges from 2 to 250.

[0005] The photosensitive polyimide precursor provided in this application, compared to the prior art, mainly introduces heterocyclic groups such as siloxanes and nitrogen-containing heterocycles, as well as photosensitive groups, onto the main chain of the photosensitive polyimide precursor. The siloxane groups form covalent anchors at the metal interface and provide stress buffering, while the nitrogen-containing heterocyclic groups provide the intrinsic heat-resistant framework and dimensional constraints of the main chain. The photosensitive groups can form an integrated cross-linked network structure through photocrosslinking. This enhances the chemical bonding strength between the photosensitive polyimide material and the metal interface, improves the interfacial adhesion and thermal stress release capabilities between the photosensitive polyimide material and the conductive metal layer, and achieves superior interfacial characteristics with the conductive metal material, thus overcoming the shortcomings of the prior art.

[0006] In some embodiments, X and Y each independently comprise any of the groups shown in the following chemical structures: , , .

[0007] In some embodiments, the photosensitive polyimide precursor comprises the following raw materials: a dianhydride monomer, a first-type diamine monomer containing a siloxane group, a second-type diamine monomer containing a heterocyclic structure, and a photosensitive monomer; wherein... The dianhydride monomers include biphenyl diether dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 5,5'-(propane-2,2-diyl)bis(isobenzofuran-1,3-dione), 2,6-naphthalenebis(trimethylammonium trimellitic acid anhydride), hexafluorodianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 2,3,3',4'-benzophenonetetracarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuran)-3-methyl-3-cyclohexene-1,2-dicarbonic anhydride, ethynyl bisphenyl anhydride, p-biphenyl-bisphenyltriester dianhydride, 4,4'-[1,4-phenylenebis(oxy)]bis(1,3-isobenzofuran dione), 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 4,4'-biphenyl ether dianhydride, bisphenol A type diether dianhydride, p-phenylene-bisphenyltriester dianhydride, 1,3-dimethyl-cyclobutanetetracarboxylic dianhydride, 4,4'-terephthalodioxydiphthalic anhydride, 2,3,3',4'-diphenyl ethertetracarboxylic dianhydride, bisphenol A type diether dianhydride, hydrogenated pyromellitic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 1,2,3, At least one of the following: 4-butanetetracarboxylic dianhydride, (4-phthalic anhydride)formyloxy-4-phthalate, bis[(3,4-dianhydride)phenyl]terephthalate, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, bis(3,4-dicarboxylated phenyl), 4,4'-(hexafluoroisopropyl)dicarboxylic anhydride, 2,2-bis(3,4-dicarboxylated phenyl)hexafluoropropane dianhydride, 4,4'-(hexafluoroisopropene)phthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and pyromellitic dianhydride; The first type of diamine monomer containing siloxane groups includes at least one of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, amino-terminated polydimethylsiloxane, and 1,3-bis(4-aminophenoxy)tetramethyldisiloxane. The second type of diamine monomer containing a heterocyclic structure includes at least one of 2-(4-aminophenyl)benzoxazole-5-amine, 2-(4-aminophenyl)benzo[d]thiazole-6-amine, 5-amino-2-(4-aminophenyl)benzofuran, 4,7-bis(4-aminophenyl)-2,1,3-benzothiadiazole, 2,7-diaminobenzothiazole, 2-aminothiazole-4-carboxamide, 2,6-diamino-4,5,6,7-tetrahydrobenzothiazole, and 4-(4-aminophenyl)-thiazole-2-amine; The photosensitive monomer includes a multifunctional acrylic monomer, which includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-4-hydroxybutyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl methacrylate.

[0008] In some embodiments, the weight-average molecular weight of the photosensitive polyimide precursor is 30,000-50,000.

[0009] In a second aspect of this application, a method for preparing the photosensitive polyimide precursor described in the first aspect is proposed, comprising the following steps: Under an inert gas atmosphere, a first-type diamine monomer containing siloxane groups and a second-type diamine monomer containing heterocyclic structures are dissolved in an organic solvent to obtain a mixed diamine solution; An acid-binding agent, a dehydrating agent, and a dianhydride monomer are added to the mixed diamine solution to carry out an imidization reaction, thereby obtaining a polyimide precursor solution. A precipitant was added to the polyimide precursor solution, and the precipitate was collected by filtration to obtain the polyimide precursor. The polyimide precursor is dissolved in an organic solvent, and then a photosensitive monomer, a dehydrating agent, and an esterification catalyst are added to carry out an esterification reaction to obtain a photosensitive polyimide precursor; or, the following steps are included: The dianhydride monomer and the photosensitive monomer were dissolved in an organic solvent and then an esterification catalyst was added to carry out an esterification ring-opening reaction to obtain a diacid diester compound containing a photosensitive group. The diacid diester compound containing the photosensitive group is subjected to an acyl chloride reaction with an acyl chloride reagent to obtain a diacyl chloride compound; A first-type diamine monomer containing a siloxane group and a second-type diamine monomer containing a heterocyclic structure are dissolved in an organic solvent and then added to the diacyl chloride compound to carry out an amidation polycondensation reaction to obtain a photosensitive polyimide precursor.

[0010] This application provides a method for preparing a photosensitive polyimide precursor. By providing a first-type diamine monomer containing siloxane groups, a second-type diamine monomer containing heterocyclic structures, and a photosensitive monomer with specific structures in the preparation process, a photosensitive polyimide precursor with the aforementioned specific structure can be obtained. This achieves better interfacial adhesion and thermal stress release capabilities between the photosensitive polyimide material and the conductive metal layer, resulting in superior interfacial properties with the conductive metal material. Furthermore, the entire process is simple to operate and requires no additional specific equipment, making it suitable for industrial production.

[0011] In some embodiments, the molar ratio of the polyimide precursor to the photosensitive monomer is 1:(0.8-1.2), the reaction temperature is 40℃-80℃, the reaction time is 5h-24h, and the reaction solvent includes at least one of N,N'-dimethylacetamide, N-methylpyrrolidone, and N,N'-dimethylformamide. The conditions for the imidization reaction include: the molar ratio of the dianhydride monomer, the first type of diamine monomer containing a siloxane group, and the second type of diamine monomer containing a heterocyclic structure is (0.9-1.01):(0.3-0.7):(0.3-0.7); the reaction temperature is 0℃-25℃; the reaction time is 8h-16h; and the reaction solvent is at least one of N,N'-dimethylacetamide, N-methylpyrrolidone, and N,N'-dimethylformamide. The conditions for the amidation polycondensation reaction include a molar ratio of the dianhydride monomer, the first type of diamine monomer containing a siloxane group, and the second type of diamine monomer containing a heterocyclic structure of (0.9-1.01):(0.3-0.7):(0.3-0.7), a reaction temperature of 0℃-25℃, a reaction time of 8h-16h, and a reaction solvent of at least one of N,N'-dimethylacetamide, N-methylpyrrolidone, and N,N'-dimethylformamide.

[0012] In a third aspect, this application proposes a photosensitive polyimide slurry, comprising the photosensitive polyimide precursor described in the first aspect or prepared by the method described in the second aspect. Thus, this photosensitive polyimide slurry, containing the aforementioned photosensitive polyimide precursor with a specific structure, can significantly improve the chemical bonding strength between the photosensitive polyimide material and the metal interface, achieving better interfacial adhesion and thermal stress release capabilities between the photosensitive polyimide material and the conductive metal layer, and obtaining superior interfacial properties with the conductive metal material.

[0013] In some embodiments, by weight, it includes: The composition includes 100 parts of photosensitive polyimide precursor, 20-250 parts of solvent, 0.1-10 parts of photocurable monomer, 0.1-13 parts of crosslinking agent, and 0.1-15 parts of photoinitiator.

[0014] In some embodiments, the solvent includes N,N'-dimethylacetamide, dimethyl sulfoxide, N,N'-dimethylformamide, N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, etc. - At least one of the following: GBL, acetone, methyl ethyl ketone, cyclopentanone, ethyl acetate, tetrahydrofuran, dioxane, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and tert-butanol, toluene, xylene, dichloromethane, and chloroform; And / or, the photocurable monomer includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl methacrylate. And / or, the crosslinking agent comprises at least one or more of tetraethylene glycol dimethacrylate, diethylene glycol acrylate, triethylene glycol dimethacrylate, 2-hydroxyethyl acrylate, or trimethylolpropane diacrylate; And / or, the photoinitiator includes benzophenone, dibenzyl ketone, 4-benzoyl-4'-methylbenzophenone, 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzoin, benzoin dimethyl ketal, benzoin-β-methoxyethyl ketal, 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. At least one of the following: 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, 1,3-diphenylpropanetrione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime, N-phenylglycine, benzoyl peroxide and α-(n-octanesulfonyloxyimino)-4-methoxybenzyl cyanide, dibenzoyl-p-quinone dioxime, acetylbenzene O-benzoyl oxime and ethyl O-(2,4,6-trimethylbenzenesulfonyl)acetylhydroxyoxime acid; And / or, by weight percentage, the solid content of the photosensitive polyimide slurry is 2 wt%-30 wt%; And / or, the viscosity of the photosensitive polyimide slurry is 300 cps-3,500 cps.

[0015] In a fourth aspect, this application discloses a photosensitive polyimide obtained by curing the photosensitive polyimide slurry described in the third aspect, wherein the coefficient of thermal expansion of the photosensitive polyimide is below 33 ppm / ℃ in the range of 30℃-330℃. Therefore, the coefficient of thermal expansion of this photosensitive polyimide remains below 33 ppm / ℃ in the range of 30℃-330℃, resulting in better matching with the coefficient of thermal expansion of the conductive metal interface. Furthermore, this photosensitive polyimide possesses all the characteristics and advantages of the aforementioned photosensitive polyimide slurry, which will not be repeated here.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The foregoing aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a scanning electron microscope (SEM) image of the photosensitive polyimide after photolithography and development in Example 1 of this application.

[0018] Figure 2 This is a scanning electron microscope (SEM) image of the photosensitive polyimide after photolithography and development in Example 1 of this application. Detailed Implementation

[0019] The embodiments of this application are described in detail below, with examples of these embodiments shown in the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application; unless otherwise stated, the values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art.

[0021] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are open-ended expressions, meaning they include what is specified in this application but do not exclude other aspects.

[0022] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0023] In the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. "First feature" and "second feature" may include one or more of that feature.

[0024] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0025] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0026] In a first aspect of this application, a photosensitive polyimide precursor is provided, having the structure shown in Chemical Formula 1 below: Chemical formula 1: ; X and Y each independently include a tetravalent aromatic group; Z is a first-class divalent group containing siloxane functional groups; W represents a type II divalent group containing a heterocyclic structure; R includes hydrogen and a monovalent organic group containing a photosensitive group, wherein the photosensitive group contains a carbon-carbon unsaturated double bond; The value of n ranges from 2 to 250.

[0027] The photosensitive polyimide precursor provided in this application, compared to the prior art, mainly introduces heterocyclic groups such as siloxanes and nitrogen-containing heterocycles, as well as photosensitive groups, onto the main chain of the photosensitive polyimide precursor. The siloxane groups form covalent anchors at the metal interface and provide stress buffering, while the nitrogen-containing heterocyclic groups provide the intrinsic heat-resistant framework and dimensional constraints of the main chain. The photosensitive groups can form an integrated cross-linked network structure through photocrosslinking. This enhances the chemical bonding strength between the photosensitive polyimide material and the metal interface, improves the interfacial adhesion and thermal stress release capabilities between the photosensitive polyimide material and the conductive metal layer, and achieves superior interfacial characteristics with the conductive metal material, thus overcoming the shortcomings of the prior art.

[0028] In this application, the aforementioned tetravalent aromatic groups may be selected from those containing a benzophenone structure or its derivatives, or at least containing an alicyclic, benzene, or fluorine structure, etc., the same below.

[0029] For example, X is a benzophenone group, a diphenyl ether group, a biphenyl group, or a derivative thereof, and may be derived from a dianhydride monomer containing at least an alicyclic structure, a benzene ring structure, a fluorine group, or a sulfone group.

[0030] For example, Y can be derived from pyromellitic anhydride and must contain at least an alicyclic, benzene-cyclic, or fluorine-structured dianhydride monomer:

[0031] , , , wait.

[0032] In this application, Z contains a siloxane functional group and can be a polyamic acid precursor containing a siloxane functional group, prepared by polycondensation reaction of a dianhydride monomer and a diamine monomer containing a siloxane group (such as 1,3-bis(3-aminopropyl)tetramethyldisiloxane); it can effectively improve the interfacial adhesion between the photosensitive material and the substrate.

[0033] In this application, W contains a heterocyclic structure, which can be triazole, pyrazole, imidazole, thiazole, pyridine, benzimidazole, carbazole, etc., which can promote the dehydration cyclization reaction of the precursor and reduce the curing temperature. In addition, the presence of N heteroatoms can also reduce the dielectric constant of the cured film, ultimately achieving low-temperature curing and high-precision photolithography.

[0034] In this application, R contains a photosensitive group, which can be a monovalent organic group of a carbon-carbon unsaturated double bond, etc.

[0035] In this application, the value of n can be 2, 50, 70, 90, 110, 150, 180, 200, 230, 250 or any of the aforementioned values.

[0036] In this application, the photosensitive polyimide precursor may comprise any of the polymers shown in the following chemical structures: , , , , wait.

[0037] In some embodiments, X and Y each independently comprise any of the groups shown in the following chemical structures: , , .

[0038] In some embodiments, the photosensitive polyimide precursor comprises the following raw materials: a dianhydride monomer, a first-type diamine monomer containing a siloxane group, a second-type diamine monomer containing a heterocyclic structure, and a photosensitive monomer; wherein... The dianhydride monomers include biphenyl diether dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 5,5'-(propane-2,2-diyl)bis(isobenzofuran-1,3-dione), 2,6-naphthalenebis(trimethylammonium trimellitic acid anhydride), hexafluorodianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 2,3,3',4'-benzophenone tetracarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuran)-3-methyl-3-cyclohexene-1,2-dicarbonic anhydride, ethynyl bisphenyl anhydride, p-biphenyl-bisphenyltriester dianhydride, 4,4'-[1,4-phenylenebis(oxy)]bis(1,3-isobenzofuran dione), 3,3', 4,4'-Benzenone tetracarboxylic dianhydride, 3,3',4,4'-Biphenyltetracarboxylic dianhydride, 2,3,3',4'-Biphenyltetracarboxylic dianhydride, 4,4'-Biphenyl ether dianhydride, Bisphenol A type diether dianhydride, p-Phenylidene-bis(phenyltrimethyl)carboxylic acid dianhydride, 1,3-Dimethyl-cyclobutanetetracarboxylic dianhydride, 4,4'-Terephthalodioxydiphthalic anhydride, 2,3,3',4'-Diphenyl ethertetracarboxylic dianhydride, Bisphenol A type diether dianhydride, Hydrogenated pyromellitic dianhydride, 1,2,3,4-Cyclobutanetetracarboxylic dianhydride, 9,9-Bis(3,4-dicarboxyphenyl)fluorene dianhydride, 1,2,3, At least one of the following: 4-butanetetracarboxylic dianhydride, (4-phthalic anhydride)formyloxy-4-phthalate, bis[(3,4-dianhydride)phenyl]terephthalate, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, bis(3,4-dicarboxylated phenyl), 4,4'-(hexafluoroisopropyl)dicarboxylic anhydride, 2,2-bis(3,4-dicarboxylated phenyl)hexafluoropropane dianhydride, 4,4'-(hexafluoroisopropene)phthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and pyromellitic dianhydride; The first type of diamine monomer containing siloxane groups includes at least one of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, amino-terminated polydimethylsiloxane, and 1,3-bis(4-aminophenoxy)tetramethyldisiloxane. The second type of diamine monomer containing a heterocyclic structure includes at least one of 2-(4-aminophenyl)benzoxazole-5-amine, 2-(4-aminophenyl)benzo[d]thiazole-6-amine, 5-amino-2-(4-aminophenyl)benzofuran, 4,7-bis(4-aminophenyl)-2,1,3-benzothiadiazole, 2,7-diaminobenzothiazole, 2-aminothiazole-4-carboxamide, 2,6-diamino-4,5,6,7-tetrahydrobenzothiazole, and 4-(4-aminophenyl)-thiazole-2-amine.

[0039] , , , , ; The photosensitive monomer includes a multifunctional acrylic monomer, which includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-4-hydroxybutyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl methacrylate.

[0040] Therefore, this application avoids designing the nitrogen-containing heterocyclic structure and siloxane onto the same diamine molecule, instead using two or more different diamine monomers, such as one containing a nitrogen-containing heterocyclic structure (but without siloxane) and another containing a siloxane (but without a nitrogen-containing heterocyclic structure). Its advantages are as follows: 1. More controllable polymerization reaction: The reactivity and main chain PI function of two or more diamine monomers can be controlled separately, avoiding mutual interference between functional groups. It is easier to adjust parameters such as molecular weight, solubility, and glass transition temperature (Tg) through copolymerization composition control.

[0041] 2. Functional decoupling facilitates performance optimization. Monomers with heterocyclic structures such as nitrogen heterocycles are responsible for: lowering the curing temperature, increasing the imidization rate, and lowering the dielectric constant.

[0042] The siloxane monomer is responsible for: improving adhesion, flexibility, and reducing water absorption. The ratio of the two can be adjusted independently to facilitate achieving a performance balance.

[0043] 3. Reduced synthesis difficulty and increased yield The synthesis of diamine monomers with nitrogen-containing heterocyclic structures (such as diamines with imidazole or triazole structures) is relatively simple and does not require the simultaneous introduction of siloxanes.

[0044] Diamines containing siloxanes (such as APDS, BAPDS, etc.) have commercial products or mature synthetic routes, avoiding complex multi-step reactions.

[0045] 4. Better storage stability of photosensitive resin: Nitrogen heterocycles and siloxanes belong to different molecular chain segments, reducing intramolecular or intermolecular catalytic hydrolysis or condensation reactions, resulting in a longer storage period for photoresist solutions.

[0046] 5. More flexible design space: Different types of nitrogen heterocycles (such as triazole, imidazole, pyridine) and different types of siloxanes (single-terminal, double-terminal, different chain lengths) and different photosensitive functional groups (such as ethyl methacrylate) can be selected according to application requirements to achieve modular design.

[0047] In some embodiments, the weight-average molecular weight of the photosensitive polyimide precursor is 30,000-50,000, for example, it can be 30,000, 30,500, 31,000, 35,000, 40,000, 41,000, 45,000, 50,000, or any range between the aforementioned values. This is beneficial for improving the resolution of the photosensitive polyimide after exposure and development.

[0048] In a second aspect of this application, a method for preparing the photosensitive polyimide precursor described in the first aspect is proposed, comprising the following steps: Under an inert gas atmosphere, a type II diamine monomer containing a heterocyclic structure and a type I diamine monomer containing a siloxane group are dissolved in an organic solvent to obtain a mixed diamine solution; An acid-binding agent, a dehydrating agent, and a dianhydride monomer are added to the mixed diamine solution to carry out an imidization reaction, thereby obtaining a polyimide precursor solution. A precipitant was added to the polyimide precursor solution, and the precipitate was collected by filtration to obtain the polyimide precursor. The polyimide precursor was dissolved in an organic solvent and then a photosensitive monomer, a dehydrating agent and an esterification catalyst were added to carry out an esterification reaction to obtain a photosensitive polyimide precursor. Alternatively, the dianhydride monomer and the photosensitive monomer are dissolved in an organic solvent and then an esterification catalyst is added to carry out an esterification ring-opening reaction to obtain a diacid diester compound containing a photosensitive group. The diacid diester compound containing the photosensitive group is subjected to an acyl chloride reaction with an acyl chloride reagent to obtain a diacyl chloride compound; A first-type diamine monomer containing a siloxane group and a second-type diamine monomer containing a heterocyclic structure are dissolved in an organic solvent and then added to the diacyl chloride compound to carry out an amidation polycondensation reaction to obtain a photosensitive polyimide precursor.

[0049] This application provides a method for preparing a photosensitive polyimide precursor. By providing a first-type diamine monomer containing siloxane groups, a second-type diamine monomer containing heterocyclic structures, and a photosensitive monomer with specific structures in the preparation process, a photosensitive polyimide precursor with the aforementioned specific structure can be obtained. This achieves better interfacial adhesion and thermal stress release capabilities between the photosensitive polyimide material and the conductive metal layer, resulting in superior interfacial properties with the conductive metal material. Furthermore, the entire process is simple to operate and requires no additional specific equipment, making it suitable for industrial production.

[0050] In some embodiments, the above preparation method is selected from either method A or method B: Method A: Step 1: Under nitrogen protection, dissolve the first type of diamine monomer containing siloxane groups and the second type of diamine monomer containing heterocyclic structures in an organic solvent and stir until completely dissolved to obtain a mixed diamine solution; Step 2: Under ice-water bath cooling conditions, add an acid-binding agent to the mixed diamine solution and stir; then slowly add a dehydrating agent and dianhydride monomer. After the addition is complete, remove the ice bath, raise the temperature to room temperature, and stir the reaction for 8-12 hours. After chemical imidization reaction, a polyimide precursor solution is obtained. Step 3: Slowly pour the reaction solution obtained in Step 2 into the precipitant to precipitate the precipitate, filter and collect the precipitate, wash it 2-3 times with the precipitant, dry it, and obtain the purified polyimide precursor solid. Step 4: The purified polyimide precursor solid obtained in Step 3 is redissolved in an organic solvent, and a photosensitive monomer, a dehydrating agent and an esterification catalyst are added. The mixture is stirred at 40℃~80℃ for 5~24 h to allow the carboxyl groups in the polyimide precursor to undergo an esterification reaction with the photosensitive monomer, thereby introducing photosensitive groups and obtaining a photosensitive polyimide precursor solution. Method B: Step 1: Dissolve the dianhydride monomer and the photosensitive monomer in an organic solvent, add the esterification catalyst, stir the reaction for 8-16 h to carry out the esterification ring-opening reaction, and obtain a diacid diester compound containing a photosensitive group. Step 2: Add an acyl chloride reagent to the reaction solution obtained in Step 1 and react at 0-5°C to convert the diacid diester compound into a diacyl chloride compound; Step 3: Dissolve the first type of diamine monomer containing siloxane groups and the second type of diamine monomer containing heterocyclic structures in an organic solvent, and slowly add them dropwise to the reaction solution obtained in Step 2 under ice-water bath conditions. After the addition is complete, remove the ice bath, raise the temperature to room temperature, and stir the reaction for 8-16 h to carry out the amidation polycondensation reaction to obtain polyamic acid compounds, i.e., photosensitive polyimide precursor solution.

[0051] In some embodiments, the conditions and parameters of the copolymerization reaction include: the molar ratio of the dianhydride monomer, the first type of diamine monomer containing a siloxane group, and the second type of diamine monomer containing a heterocyclic structure is (0.9-1.01):(0.3-0.7):(0.3-0.7); the reaction temperature is 0℃-25℃; the reaction time is 8h-16h; and the reaction solvent includes at least one of N,N'-dimethylacetamide (DMAc), N-methylpyrrolidone, and N,N'-dimethylformamide. And / or, the conditions and parameters of the esterification reaction include: the molar ratio of the polyimide compound to the photosensitive monomer is (1):(0.8-1.2), the reaction temperature is 40℃-80℃, the reaction time is 5h-24h, and the reaction solvent includes at least one of N,N'-dimethylacetamide (DMAc), N-methylpyrrolidone, and N,N'-dimethylformamide; And / or, the conditions for the imidization reaction include: a reaction temperature of 150°C-250°C, a reaction time of 60 seconds-1 hour, and a reaction solvent including at least one of N,N'-dimethylacetamide (DMAc), N-methylpyrrolidone, and N,N'-dimethylformamide.

[0052] In a third aspect, this application proposes a photosensitive polyimide slurry, comprising the photosensitive polyimide precursor described in the first aspect or prepared by the method described in the second aspect. Thus, this photosensitive polyimide slurry, containing the aforementioned photosensitive polyimide precursor with a specific structure, can significantly improve the chemical bonding strength between the photosensitive polyimide material and the metal interface, achieving better interfacial adhesion and thermal stress release capabilities between the photosensitive polyimide material and the conductive metal layer, and obtaining superior interfacial properties with the conductive metal material.

[0053] In some embodiments, by weight, it includes: The composition includes 100 parts of photosensitive polyimide precursor, 20-250 parts of solvent, 0.1-10 parts of photocurable monomer, 0.1-13 parts of crosslinking agent, and 0.1-15 parts of photoinitiator.

[0054] Therefore, the photosensitive polyimide slurry contains a photosensitive polyimide precursor with pre-functionalized main chain (nitrogen heterocycle + siloxane), a photocurable monomer, and a crosslinking agent. By separating the main chain functionalization (nitrogen heterocycle + siloxane) from the side chain / crosslinking photosensitive system, low-temperature curing and high-precision photolithography are achieved. At the same time, the catalytic and crosslinking synergistic mechanism between the main chain nitrogen heterocycle and the external photosensitive monomer is utilized to enhance the chemical bonding between the conductive metal and the PSPI material interface.

[0055] As an example, the weight of the solvent can be 20 parts, 50 parts, 100 parts, 180 parts, 250 parts, or any of the aforementioned values.

[0056] As an example, the weight parts of the photocurable monomer can be 0.1 parts, 0.5 parts, 5 parts, 8 parts, 10 parts, or any of the aforementioned values.

[0057] As an example, the weight percentage of the crosslinking agent can be 0.1 parts, 0.5 parts, 5 parts, 8 parts, 13 parts, or any of the aforementioned values.

[0058] As an example, the weight of the photoinitiator can be 0.1 parts, 0.5 parts, 5 parts, 10 parts, 15 parts, or any of the aforementioned values.

[0059] In addition, the photosensitive polyimide slurry also includes other components in parts by weight of 0.01 to 10 (e.g., 0.1, 0.5, 5, 10, etc.); the other components include at least one of an acid-binding agent, a primary amine hydrochloride, and a tackifier; the mass ratio of the acid-binding agent (organic base) to the photosensitive polyimide precursor resin is 0.1 to 5 (e.g., 0.1, 0.5, 1, 2, 5, etc.): 100; the mass ratio of the primary amine hydrochloride to the photosensitive polyimide precursor resin is 0.1 to 15 (e.g., 0.1, 0.5, 1, 2, 5, 15, etc.): 100; the mass ratio of the tackifier to the photosensitive polyimide precursor resin is 0.1 to 15 (e.g., 0.1, 0.5, 1, 2, 5, 15, etc.): 100.

[0060] In some embodiments, the solvent includes N,N'-dimethylacetamide, dimethyl sulfoxide, N,N'-dimethylformamide, N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, etc. - At least one of the following: GBL, acetone, methyl ethyl ketone, cyclopentanone, ethyl acetate, tetrahydrofuran, dioxane, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and tert-butanol, toluene, xylene, dichloromethane, and chloroform; And / or, the photocurable monomer includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl methacrylate. And / or, the crosslinking agent comprises at least one or more of tetraethylene glycol dimethacrylate, diethylene glycol acrylate, triethylene glycol dimethacrylate, 2-hydroxyethyl acrylate, or trimethylolpropane diacrylate; And / or, the photoinitiator includes benzophenone, dibenzyl ketone, 4-benzoyl-4'-methylbenzophenone, 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzoin, benzoin dimethyl ketal, benzoin-β-methoxyethyl ketal, 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. At least one of the following: 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, 1,3-diphenylpropanetrione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime, N-phenylglycine, benzoyl peroxide and α-(n-octanesulfonyloxyimino)-4-methoxybenzyl cyanide, dibenzoyl-p-quinone dioxime, acetylbenzene O-benzoyl oxime and ethyl O-(2,4,6-trimethylbenzenesulfonyl)acetylhydroxyoxime acid; And / or, by mass percentage, the solid content of the photosensitive polyimide slurry is 2wt%-30wt%, for example, it can be 2wt%, 8wt%, 15wt%, 20wt%, 25wt%, 30wt% or any range between the aforementioned values; And / or, the viscosity of the photosensitive polyimide slurry is 300 cps-3,500 cps, for example, it can be 300 cps, 500 cps, 1,000 cps, 2,000 cps, 3,000 cps, 3,500 cps or any range between the aforementioned values.

[0061] In a fourth aspect of this application, a photosensitive polyimide is proposed, obtained by curing the photosensitive polyimide slurry described in the third aspect. The photosensitive polyimide has a coefficient of thermal expansion of less than 33 ppm / ℃ in the temperature range of 30℃-330℃. Therefore, the coefficient of thermal expansion of this photosensitive polyimide is maintained below 33 ppm / ℃ in the temperature range of 30℃-330℃, resulting in better matching with the coefficient of thermal expansion of the conductive metal interface. Furthermore, this photosensitive polyimide possesses all the characteristics and advantages of the aforementioned photosensitive polyimide slurry, such as: introducing a diamine monomer with a nitrogen heterocyclic and siloxane structure and photosensitive functional groups into the resin precursor to prepare the photosensitive polyimide. The polymer contains a nitrogen heterocyclic structure, which can promote the dehydration and cyclization reaction of the precursor, thereby reducing the curing temperature; simultaneously, the presence of siloxane can effectively improve the interfacial adhesion between the photosensitive material and the substrate, and the photosensitive functional groups achieve photocrosslinking. The main chain functionalization (nitrogen heterocycle + siloxane) is separated from the side chain / crosslinked photosensitive system to achieve low-temperature curing and high-precision photolithography; the chemical bonding of narrow trench interfaces is enhanced by utilizing the synergistic mechanism of "catalysis and crosslinking" between the main chain nitrogen heterocycle and the externally applied photocurable monomer.

[0062] In some specific embodiments, the photocuring conditions include wavelengths of 254nm, 365nm, or 405nm and a concentration of 10-400mW / cm². 2 (For example, it could be 10mW / cm) 2 100mW / cm 2 200mW / cm 2 400mW / cm 2 Light intensity (etc.) or 40-2000 mJ / cm 2 (For example, it could be 40mJ / cm) 2 80mJ / cm 2 100mJ / cm 2 400mJ / cm 2 500mJ / cm 2 1000mJ / cm 2 2000mJ / cm 2 The exposure dose is adjusted to regulate the crosslinked network structure.

[0063] In some specific embodiments, the coefficient of thermal expansion of the photosensitive polyimide can be in the range of 5-40 ppm / K (e.g., 5 ppm / K, 15 ppm / K, 25 ppm / K, 30 ppm / K, 40 ppm / K, etc.).

[0064] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0065] The following specific embodiments illustrate the solution of this application. It should be noted that these embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0066] Example 1 This embodiment provides a photosensitive polyimide precursor and a polyimide slurry and a polyimide film including the photosensitive polyimide precursor, comprising the following processes:

[0067] Under nitrogen protection, 5.60 g (0.025 mol) of 5-amino-2-(4-aminophenyl)benzofuran and 6.21 g (0.025 mol) of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were dissolved in 250 mL of N,N'-dimethylacetamide (DMAc) solution and stirred until completely dissolved. Under ice-water bath cooling, 12 g of triethylamine (TEA) was first added to the polyimide solution and stirred for 10 min. Then, 50 g of trifluoroacetic anhydride (TFAA) was slowly added dropwise with stirring until it reached a solution of 16.11 g of 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride (0.05 mol). After the addition was complete, the mixture was heated to room temperature and stirred for 10 h. The reaction solution was then slowly poured into 500 mL of isopropanol (or a methanol / water mixture) to precipitate the precipitate. The precipitate was collected by filtration and washed 2-3 times with isopropanol to complete purification. 6.51 g (0.05 mol) of hydroxyethyl methacrylate and 10.32 g (0.05 mol) of dicyclohexylcarbodiimide / 6.12 g (0.05 mol) of 4-dimethylaminopyridine (DCC / DMAP) were weighed and esterified to obtain a diacid diester, which was stirred at 52 °C for 12 h. Finally, 6.49 g of photoinitiator (benzoyl-p-quinone dioxime) and 2.17 g of crosslinking agent (2-hydroxyethyl acrylate) were added to the purified polyimide precursor solution, and the mixture was stirred for 12-18 h to obtain the negative PSPI resin. The polyimide precursor had a viscosity of 1,890 cps and a weight-average molecular weight of 42,000.

[0068] Curing process: Pre-curing: The slurry is applied to the substrate by spin coating (1,500 rpm / min) or inkjet printing, and cured at 110°C for 120 seconds to remove most of the solvent and initially form a 25-micron film. Exposure crosslinking: Under ultraviolet light irradiation at a wavelength of 365 nm, the exposure dose is 500 mJ / cm. 2 ; Thermosetting: Under a nitrogen atmosphere, the temperature is raised to 120℃ / 240s. The baked film is then developed using TMAH (2.38%) in a developing device. The developed pattern is observed using a scanning electron microscope, and any residual adhesive or adhesive drift is checked. The imidization rate after curing is ≥85% (confirmed by FT-IR spectroscopy at 1780 cm⁻¹). -1 and 1720cm -1 (Imidium characteristic peak).

[0069] The chemical structural formula of the photosensitive polyimide precursor obtained in this embodiment is shown below: .

[0070] Example 2 This embodiment provides a photosensitive polyimide precursor and a polyimide slurry and a polyimide film including the photosensitive polyimide precursor, comprising the following processes: Under nitrogen protection, 5.63 g (0.025 mol) of 2-(4-aminophenyl)benzoxazole-5-amine and 6.21 g (0.025 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane were dissolved in 250 mL of N,N'-dimethylacetamide (DMAc) solution and stirred until completely dissolved. Under ice-water bath cooling, 12 g of triethylamine (TEA) was first added to the polyimide solution and stirred for 10 min. Then, 50 g of trifluoroacetic anhydride (TFAA) was slowly added dropwise with stirring until it reached a solution of 25.41 g of 2,6-naphthobis(trimethoxybenzoic acid anhydride) (0.05 mol). After the addition was complete, the solution was heated to room temperature and stirred for 8-12 seconds. The reaction mixture was slowly poured into 500 mL of isopropanol (or methanol / water mixture) to precipitate the precipitate. The precipitate was then collected by filtration and washed 2-3 times with isopropanol to complete the purification. 6.51 g (0.05 mol) of hydroxyethyl methacrylate and 10.32 g (0.05 mol) of dicyclohexylcarbodiimide / 6.12 g (0.05 mol) of 4-dimethylaminopyridine (DCC / DMAP) were weighed and esterified to obtain a diacid diester. The diacid diester was then heated at 52 °C. o The mixture was stirred at C for 8-16 hours. Finally, 6.49 g of photoinitiator (benzoyl-p-quinone dioxime) and 2.17 g of crosslinking agent (2-hydroxyethyl acrylate) were added to the purified polyimide precursor solution, and the mixture was stirred for 12-18 hours to obtain the negative PSPI resin. The polyimide precursor had a viscosity of 2,290 cps and a weight-average molecular weight of 42,200.

[0071] Curing process: Pre-curing: The slurry is applied to the substrate by spin coating (1500 rpm / min) or inkjet printing, and cured at 120℃ for 120s to remove most of the solvent and initially form a 20-micron film. Exposure crosslinking: Under ultraviolet light irradiation at a wavelength of 365 nm, the exposure dose is 800 mJ / cm. 2 ; Thermosetting: Under a nitrogen atmosphere, the temperature is raised to 125℃ / 240s. The baked film is then developed with cyclopentanone in a developing device. The developed pattern is observed using a scanning electron microscope, and any residual adhesive or glue drift is checked. The imidization rate after curing is ≥88% (confirmed by FT-IR spectroscopy at 1780 cm⁻¹). -1 and 1720cm -1 (Imidium characteristic peak).

[0072] The chemical structural formula of the photosensitive polyimide precursor obtained in this embodiment is shown below: .

[0073] Example 3 This embodiment provides a photosensitive polyimide precursor and a polyimide slurry and a polyimide film including the photosensitive polyimide precursor, comprising the following processes: 10.9 g (0.05 mol) of pyromellitic dianhydride and 5.81 g (0.05 mol) of hydroxyethyl acrylate were weighed and dissolved in 50 mL of N-methylpyrrolidone. 6.12 g (0.05 mol) of 4-dimethylaminopyridine was added for esterification to obtain a diacid diester (stirring for 8-16 h). Subsequently, 11.9 g (0.05 mol) of thionyl chloride, 5.6 g (0.025 mol) of 2-(4-aminophenyl)benzoxazole-5-amine, and 6.21 g (0.025 mol) of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were added to react and obtain a polyimide precursor. The product slurry was then dropped into 500 mL of isopropanol to precipitate as a powder. The precipitate was then filtered, collected, and dried. This process was repeated at least 2-3 times to complete the purification. Finally, 6.49 g of photoinitiator (benzoyl-p-quinone dioxime) and 2.17 g of crosslinking agent (2-hydroxyethyl acrylate) were added to the purified polyimide precursor solution, and the mixture was stirred for 12-18 h to obtain negative PSPI resin. The polyimide precursor had a viscosity of 1,690 cps and a weight-average molecular weight of 35,000.

[0074] Curing process: Pre-curing: The slurry is applied to the substrate by spin coating (2000 rpm / min) or inkjet printing, and cured at 100°C for 100 seconds to remove most of the solvent and initially form a 25-micron adhesive film. Exposure crosslinking: Under ultraviolet light irradiation at a wavelength of 365 nm, the exposure dose is 600 mJ / cm. 2 ; Thermosetting: Under a nitrogen atmosphere, the temperature is raised to 125℃ / 240s. The baked film is then developed with cyclopentanone in a developing device. The developed pattern is observed using a scanning electron microscope, and any residual adhesive or glue drift is checked. The imidization rate after curing is ≥92% (confirmed by FT-IR spectroscopy at 1780 cm⁻¹). -1 and 1720cm -1 (Imidium characteristic peak).

[0075] The chemical structural formula of the photosensitive polyimide precursor obtained in this embodiment is shown below: .

[0076] Example 4 This embodiment provides a photosensitive polyimide precursor and a polyimide slurry and a polyimide film including the photosensitive polyimide precursor, comprising the following processes: Under nitrogen protection, 3.78 g (0.025 mol) of 4,7-bis(4-aminophenyl)-2,1,3-benzothiadiazole and 6.21 g (0.025 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane were dissolved in 250 mL of N,N'-dimethylacetamide (DMAc) solution and stirred until completely dissolved. Under ice-water bath cooling, 12 g of triethylamine (TEA) was first added to the polyimide solution and stirred for 10 min. Then, 50 g of trifluoroacetic anhydride (TFAA) was slowly added dropwise with stirring until it reached a solution of 14.71 g of 2,3,3',4'-biphenyltetracarboxylic dianhydride (0.05 mol). After the addition was complete, the solution was heated to room temperature and stirred for 8-12 seconds. The reaction mixture was then slowly poured into 500 mL of isopropanol (or a methanol / water mixture) to precipitate the precipitate. The precipitate was collected by filtration and washed 2-3 times with isopropanol to complete purification. 6.51 g (0.05 mol) of hydroxyethyl methacrylate and 10.32 g (0.05 mol) of dicyclohexylcarbodiimide / 6.12 g (0.05 mol) of 4-dimethylaminopyridine (DCC / DMAP) were weighed and esterified to obtain a diacid diester. The diacid diester was then heated at 52 °C. o The mixture was stirred at C for 8-16 hours. Finally, 6.49 g of photoinitiator (benzoyl-p-quinone dioxime) and 2.17 g of crosslinking agent (2-hydroxyethyl acrylate) were added to the purified polyimide precursor solution, and the mixture was stirred for 12-18 hours to obtain the negative PSPI resin. The polyimide precursor had a viscosity of 2,340 cps and a weight-average molecular weight of 41,250.

[0077] Curing process: Pre-curing: The slurry is applied to the substrate by spin coating (1,500 rpm / min) or inkjet printing, and cured at 120°C for 120 seconds to remove most of the solvent and initially form a 20-micron film. Exposure crosslinking: Under ultraviolet light irradiation at a wavelength of 365 nm, the exposure dose is 800 mJ / cm. 2 ; Thermosetting: Under a nitrogen atmosphere, the temperature is raised to 120℃ / 240s. The baked film is then subjected to TMAH development in a developing device. The developed pattern is observed using a scanning electron microscope, and any residual adhesive or adhesive drift is checked. The imidization rate after curing is ≥84% (confirmed by FT-IR spectroscopy at 1780 cm⁻¹). -1 and 1720cm -1 (Imidium characteristic peak).

[0078] The chemical structural formula of the photosensitive polyimide precursor obtained in this embodiment is shown below: .

[0079] Example 5 This embodiment provides a photosensitive polyimide precursor and a polyimide slurry and a polyimide film including the photosensitive polyimide precursor, comprising the following processes: Weigh 22.21 g (0.05 mol) of 4,4'-(hexafluoroisopropene)phthalic anhydride and 5.81 g (0.05 mol) of hydroxyethyl acrylate, dissolve them in N-methylpyrrolidone (50 mL), and add 6.12 g (0.05 mol) of 4-dimethylaminopyridine for esterification to obtain a diacid diester (stirring for 8-16 h). Subsequently, add 11.9 g of thionyl chloride (0.05 mol), 5.6 g (0.025 mol) of 2-(4-aminophenyl)benzoxazole-5-amine, and 6.21 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (0.025 mol) to react and obtain a polyimide precursor. Then, dropwise add the product slurry into 500 mL of isopropanol to precipitate it as a powder, filter it, collect the powder sample and dry it. Repeat the above operation at least 2-3 times to complete the purification. Finally, 6.49 g of photoinitiator (benzoyl-p-quinone dioxime) and 2.17 g of crosslinking agent (2-hydroxyethyl acrylate) were added to the purified polyimide precursor solution, and the mixture was stirred for 12-18 h to obtain negative PSPI resin. The polyimide precursor had a viscosity of 1,690 cps and a weight-average molecular weight of 42,300.

[0080] Curing process: Pre-curing: The slurry is applied to the substrate by spin coating (2,000 rpm / min) or inkjet printing, and cured at 120℃ for 120s to remove most of the solvent and initially form a 25-micron film. Exposure crosslinking: Under ultraviolet light irradiation at a wavelength of 365 nm, the exposure dose is 600 mJ / cm. 2 ; Thermosetting: Under a nitrogen atmosphere, the temperature is raised to 120℃ / 240s. The baked film is then developed with cyclopentanone in a developing device. The developed pattern is observed using a scanning electron microscope, and any residual adhesive or glue drift is checked. The imidization rate after curing is ≥92% (confirmed by FT-IR spectroscopy at 1780 cm⁻¹). -1 and 1720cm -1 (Imidium characteristic peak).

[0081] The chemical structural formula of the photosensitive polyimide precursor obtained in this embodiment is shown below: .

[0082] Example 6 This embodiment provides a photosensitive polyimide precursor and a polyimide slurry and a polyimide film including the photosensitive polyimide precursor, comprising the following processes: 16.11 g (0.05 mol) of benzophenone tetracarboxylic dianhydride and 5.81 g (0.05 mol) of hydroxyethyl acrylate were weighed and dissolved in N-methylpyrrolidone (50 mL). 10.32 g of dicyclohexylcarbodiimide (0.05 mol) and 6.12 g (0.05 mol) of 4-dimethylaminopyridine were added to esterify and give a diacid diester (stirred for 8-16 h). Subsequently, 11.9 g of thionyl chloride (0.05 mol), 4.78 g (0.025 mol) of 2-amino-4-(4-aminophenyl)thiazole and 6.21 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (0.025 mol) were added to react and give a polyimide precursor. Then, the product slurry was dropped into 500 mL of isopropanol to precipitate as a powder. The precipitate was then filtered, collected, and dried. This process was repeated at least 2-3 times to complete the purification. Finally, 6.49 g of photoinitiator (benzoyl-p-quinone dioxime) and 2.17 g of crosslinking agent (2-hydroxyethyl acrylate) were added to the purified polyimide precursor solution, and the mixture was stirred for 12-18 h to obtain the negative PSPI resin. The polyimide precursor had a viscosity of 1,900 cps and a weight-average molecular weight of 38,000.

[0083] Curing process: Pre-curing: The slurry is applied to the substrate by spin coating (2,000 rpm / min) or inkjet printing, and cured at 120℃ for 120s to remove most of the solvent and initially form a 25-micron film. Exposure crosslinking: Under ultraviolet light irradiation at a wavelength of 365 nm, the exposure dose is 500 mJ / cm. 2 ; Thermosetting: Under a nitrogen atmosphere, the temperature is raised to 120℃ / 240s. The baked film is then developed with cyclopentanone in a developing device. The developed pattern is observed using a scanning electron microscope, and any residual adhesive or glue drift is checked. The imidization rate after curing is ≥92% (confirmed by FT-IR spectroscopy at 1780 cm⁻¹). -1 and 1720cm -1 (Imidium characteristic peak).

[0084] Test Example 1 This test case performs performance tests on the above embodiments and comparative examples, and the test results are shown in Table 1. The specific test methods include: 1. Imidification rate (DOI) (%) In this application, the degree of blocking reaction was determined by Jasco's Fourier transform infrared spectroscopy FTIR-8XFV, and the imidization rate was calculated by monitoring characteristic peaks; PAA characteristic peak: C=O stretching vibration of the carboxyl group (-COOH): ~1720 cm⁻¹ -1 (Broad peak); C=O stretching vibration of amide (-CONH-): ~1660 cm⁻¹ -1 .

[0085] PI characteristic peak: imide C=O asymmetric stretching vibration: ~1780cm -1 (Sharp); Imidine C=O symmetric stretching vibration: ~1720cm -1 imide ring CN stretching vibration: ~1380cm -1 ) Method: PAA solution was coated onto a KBr salt plate or silicon wafer to form a uniform thin film, followed by stepwise temperature increase for curing. After curing, samples were taken for Fourier transform infrared (FTIR) testing, with a scanning range of 4000-4000 cm⁻¹. -1 4cm resolution - ¹.

[0086] Quantitative analysis: Select the internal standard peak (e.g., the C=C stretching vibration of the benzene ring ~1510 cm⁻¹). - ¹, unaffected by the reaction.

[0087] Calculate the imidization rate (DOI): ; Aimide@1380cm - ¹TargetTemp: The peak area of ​​the CN stretching vibration of the imide ring at the target temperature; Aaromatic@1510cm - ¹TargetTemp: The area of ​​the C=C stretching vibration peak of the benzene ring at the target temperature; Aimide@1380cm - ¹Film: The peak area of ​​the imide ring CN stretching vibration after the film is fully cured; Aaromatic@1510cm - ¹Film: The area of ​​the C=C stretching vibration peak of the benzene ring after the film has been fully cured.

[0088] 2. Coefficient of thermal expansion (CTE) The coefficient of thermal expansion was tested using a Thermomechanical Analyzer TMA450 from TA Instruments.

[0089] Methods: ① Sample preparation: Cut the film sample into a rectangle, 5-10 mm in length and 4-5 mm in width (ensure the edges are smooth and burr-free); ② The film is held vertically in the tension fixture, ensuring the long axis is parallel to the probe displacement direction; ③ Initial calibration: Input the initial sample length (manual measurement or automatic recording by the equipment), the probe lightly touches the sample surface, and the displacement is zeroed after applying a preload; ④ Programmed temperature rise: Heat at a set rate and record the displacement-temperature curve in real time; ⑤ Data processing in software: The data processing and analysis are performed using the software included with the TMA450.

[0090]

[0091] Where L: initial length (unit: m); ΔL: absolute expansion within the temperature range ΔT (unit: m); ΔT: selected temperature range (unit: °C).

[0092] Table 1

[0093] also, Figure 1 These are scanning electron microscope (SEM) images of photosensitive polyimide after photolithography and development. Figure 2 The images are scanning electron microscope (SEM) images of photosensitive polyimide after photolithography and development.

[0094] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A photosensitive polyimide precursor, characterized in that, It has the structure shown in Chemical Formula 1: Chemical formula 1: ; X and Y each independently include a tetravalent aromatic group; Z is a first-class divalent group containing siloxane functional groups; W represents a type II divalent group containing a heterocyclic structure; R includes hydrogen and a monovalent organic group containing a photosensitive group, wherein the photosensitive group contains a carbon-carbon unsaturated double bond; The value of n ranges from 2 to 250.

2. The photosensitive polyimide precursor according to claim 1, characterized in that, X and Y each independently include any of the groups shown in the following chemical structures: 、 、 。 3. The photosensitive polyimide precursor according to claim 1 or 2, characterized in that, The photosensitive polyimide precursor comprises the following raw materials: a dianhydride monomer, a first-type diamine monomer containing a siloxane group, a second-type diamine monomer containing a heterocyclic structure, and a photosensitive monomer; wherein... The dianhydride monomers include biphenyl diether dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 5,5'-(propane-2,2-diyl)bis(isobenzofuran-1,3-dione), 2,6-naphthalenebis(trimethylammonium trimellitic acid anhydride), hexafluorodianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 2,3,3',4'-benzophenonetetracarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuran)-3-methyl-3-cyclohexene-1,2-dicarbonic anhydride, ethynyl bisphenyl anhydride, p-biphenyl-bisphenyltriester dianhydride, 4,4'-[1,4-phenylenebis(oxy)]bis(1,3-isobenzofuran dione), 3,3',4, 4'-Benzenone tetracarboxylic dianhydride, 3,3',4,4'-Biphenyltetracarboxylic dianhydride, 2,3,3',4'-Biphenyltetracarboxylic dianhydride, 4,4'-Biphenyl ether dianhydride, Bisphenol A type diether dianhydride, p-Phenylidene-bis(phenyltrimethyl)carboxylic acid dianhydride, 1,3-Dimethyl-cyclobutanetetracarboxylic dianhydride, 4,4'-Terephthalodioxydiphthalic anhydride, 2,3,3',4'-Diphenyl ethertetracarboxylic dianhydride, Bisphenol A type diether dianhydride, Hydrogenated pyromellitic dianhydride, 1,2,3,4-Cyclobutanetetracarboxylic dianhydride, 9,9-Bis(3,4-dicarboxyphenyl)fluorene dianhydride, 1,2,3, At least one of the following: 4-butanetetracarboxylic dianhydride, (4-phthalic anhydride)formyloxy-4-phthalate, bis[(3,4-dianhydride)phenyl]terephthalate, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, bis(3,4-dicarboxylated phenyl), 4,4'-(hexafluoroisopropyl)dicarboxylic anhydride, 2,2-bis(3,4-dicarboxylated phenyl)hexafluoropropane dianhydride, 4,4'-(hexafluoroisopropene)phthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and pyromellitic dianhydride; The first type of diamine monomer containing siloxane groups includes at least one of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, amino-terminated polydimethylsiloxane, and 1,3-bis(4-aminophenoxy)tetramethyldisiloxane. The second type of diamine monomer containing a heterocyclic structure includes at least one of 2-(4-aminophenyl)benzoxazole-5-amine, 2-(4-aminophenyl)benzo[d]thiazole-6-amine, 5-amino-2-(4-aminophenyl)benzofuran, 4,7-bis(4-aminophenyl)-2,1,3-benzothiadiazole, 2,7-diaminobenzothiazole, 2-aminothiazole-4-carboxamide, 2,6-diamino-4,5,6,7-tetrahydrobenzothiazole, and 4-(4-aminophenyl)-thiazole-2-amine; The photosensitive monomer includes a multifunctional acrylic monomer, which includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-4-hydroxybutyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl methacrylate.

4. The photosensitive polyimide precursor according to claim 3, characterized in that, The weight-average molecular weight of the photosensitive polyimide precursor is 30,000-50,000.

5. A method for preparing the photosensitive polyimide precursor according to any one of claims 1-4, characterized in that, Includes the following steps: Under an inert gas atmosphere, a first-type diamine monomer containing siloxane groups and a second-type diamine monomer containing heterocyclic structures are dissolved in an organic solvent to obtain a mixed diamine solution; An acid-binding agent, a dehydrating agent, and a dianhydride monomer are added to the mixed diamine solution to carry out an imidization reaction, thereby obtaining a polyimide precursor solution. A precipitant was added to the polyimide precursor solution, and the precipitate was collected by filtration to obtain the polyimide precursor. The polyimide precursor is dissolved in an organic solvent, and then a photosensitive monomer, a dehydrating agent, and an esterification catalyst are added to carry out an esterification reaction to obtain the photosensitive polyimide precursor; or, the following steps are included: The dianhydride monomer and the photosensitive monomer were dissolved in an organic solvent and then an esterification catalyst was added to carry out an esterification ring-opening reaction to obtain a diacid diester compound containing a photosensitive group. The diacid diester compound containing the photosensitive group is subjected to an acyl chloride reaction with an acyl chloride reagent to obtain a diacyl chloride compound; The first type of diamine monomer containing siloxane groups and the second type of diamine monomer containing heterocyclic structures are dissolved in an organic solvent and then added to the diacyl chloride compound to carry out an amidation polycondensation reaction to obtain the photosensitive polyimide precursor.

6. The preparation method according to claim 5, characterized in that, The conditions for the esterification reaction include: the molar ratio of the polyimide precursor to the photosensitive monomer is 1:(0.8-1.2), the reaction temperature is 40℃-80℃, the reaction time is 5h-24h, and the reaction solvent includes at least one of N,N'-dimethylacetamide, N-methylpyrrolidone, and N,N'-dimethylformamide. The conditions for the iminolation reaction include: the molar ratio of the dianhydride monomer, the first type of diamine monomer containing a siloxane group, and the second type of diamine monomer containing a heterocyclic structure is (0.9-1.01):(0.3-0.7):(0.3-0.7); the reaction temperature is 0℃-25℃; the reaction time is 8h-16h; and the reaction solvent is at least one of N,N'-dimethylacetamide, N-methylpyrrolidone, and N,N'-dimethylformamide. The conditions for the amidation polycondensation reaction include a molar ratio of the dianhydride monomer, the first type of diamine monomer containing a siloxane group, and the second type of diamine monomer containing a heterocyclic structure of (0.9-1.01):(0.3-0.7):(0.3-0.7), a reaction temperature of 0℃-25℃, a reaction time of 8h-16h, and a reaction solvent of at least one of N,N'-dimethylacetamide, N-methylpyrrolidone, and N,N'-dimethylformamide.

7. A photosensitive polyimide paste, characterized in that, Includes the photosensitive polyimide precursor according to any one of claims 1-4 or the photosensitive polyimide precursor prepared by the method of preparing the photosensitive polyimide precursor according to any one of claims 5-6.

8. The photosensitive polyimide slurry according to claim 7, characterized in that, By weight, it includes: The composition includes 100 parts of photosensitive polyimide precursor, 20-250 parts of solvent, 0.1-10 parts of photocurable monomer, 0.1-13 parts of crosslinking agent, and 0.1-15 parts of photoinitiator.

9. The photosensitive polyimide slurry according to claim 8, characterized in that, The solvents include N,N'-dimethylacetamide, dimethyl sulfoxide, N,N'-dimethylformamide, N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, and ethylene glycol dimethyl ether. - At least one of the following: GBL, acetone, methyl ethyl ketone, cyclopentanone, ethyl acetate, tetrahydrofuran, dioxane, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and tert-butanol, toluene, xylene, dichloromethane, and chloroform; And / or, the photocurable monomer includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl methacrylate. And / or, the crosslinking agent comprises at least one or more of tetraethylene glycol dimethacrylate, diethylene glycol acrylate, triethylene glycol dimethacrylate, 2-hydroxyethyl acrylate, or trimethylolpropane diacrylate; And / or, the photoinitiator includes benzophenone, dibenzyl ketone, 4-benzoyl-4'-methylbenzophenone, 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzoin, benzoin dimethyl ketal, benzoin-β-methoxyethyl ketal, 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl At least one of the following: 1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, 1,3-diphenylpropanetrione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime, N-phenylglycine, benzoyl peroxide and α-(n-octanesulfonyloxyimino)-4-methoxybenzyl cyanide, dibenzoyl-p-quinone dioxime, acetylbenzyl O-benzoyl oxime and ethyl O-(2,4,6-trimethylbenzenesulfonyl)acetylhydroxyoxime acid; And / or, by weight percentage, the solid content of the photosensitive polyimide slurry is 2 wt%-30 wt%; And / or, the viscosity of the photosensitive polyimide slurry is 300 cps-3,500 cps.

10. A photosensitive polyimide, characterized in that, The photosensitive polyimide obtained by curing the photosensitive polyimide slurry according to any one of claims 7-9 has a coefficient of thermal expansion of less than 33 ppm / ℃ in the range of 30℃-330℃.

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