WO2023133943A1 - Cross-linked polyamic acid ester and preparation method therefor, polyimide composition comprising same, and method for preparing polyimide resin film - Google Patents

Abstract

A cross-linked polyamic acid ester. The cross-linked polyamic acid ester has structural units linked by means of a cross-linked structure. Each structural unit has a structure as shown in general formula I, wherein Ar₁ is a dianhydride monomer residue, Ar₂ is a diamine monomer residue, and ﹋ is a linking site linked to the cross-linked structure; and n in each structural unit is independently selected from any integer in the range of 5-2000. The cross-linked structure -AR₃- is a polyphenol cross-linking agent residue. By means of a cross-linked network, a polyamic acid ester can effectively resist development by an alkaline developing solution; and a small amount of a photo acid generator or photo base generator is used for generating an organic strong acid or organic strong base to hydrolyze the polyamic acid ester in order to form an alkaline soluble polyamic acid, such that a relatively large dissolution rate contrast value can be obtained, and furthermore a polyimide resin film having a good positive pattern quality, a high heat-resistant resolution, a high sensitivity and a large contrast ratio can be formed.

Description

Cross-linked polyamic acid ester, preparation method thereof, polyimide composition containing same, and preparation method of polyimide resin film technical field

The present invention relates to organic chemistry, specifically, to a cross-linked polyamic acid ester, a preparation method thereof, a polyimide composition containing the same, and a preparation method of a polyimide resin film.

Background technique

With the rapid development of microelectronics, semiconductor and other fields, higher requirements are put forward for the miniaturization, miniaturization and refinement of electronic instruments and semiconductor devices. higher requirement.

As one of the core materials in the fields of microelectronics, semiconductor, aerospace and other fields, the development of photosensitive polyimide is of great significance. Polyimide can be converted into stable polyimide by reheating in the form of various precursors, such as polyamic acid, polyamide ester and polyisoimide. According to the different photochemical mechanism, photosensitive polyimide is divided into positive photoresist (p-PSPI), negative photoresist (n-PSPI) and chemically amplified (CA) photoresist. Positive photosensitive polyimide is generally photodegradable, and the resulting pattern is the same as the mask; negative photosensitive polyimide is generally photocrosslinked, and the resulting pattern is opposite to the mask; chemically amplified photosensitive polyimide Amines can be used to obtain both positive photosensitive polyimide and negative photosensitive polyimide. Due to its high photon quantum yield, the resulting photoresist has high resolution and high contrast.

Most of the commercially available photosensitive polyimides are negative photosensitive polyimides, but negative photosensitive polyimides have disadvantages such as low resolution and most of them use organic developing solutions that will erode photolithographic patterns. Photosensitive polyimide has attracted much attention due to its advantages of high resolution, development with alkaline aqueous solution, and environmental friendliness.

So far, most positive photosensitive polyimides are mainly DNQ-type photosensitive polyimides. Although DNQ-type photosensitive polyimides have improved their resolution, because DNQ-type photosensitive agents are all Relatively large molecules are not easy to remove during the imidization process, which seriously affects the heat resistance and mechanical properties of the polyimide film.

Contents of the invention

The main purpose of the present invention is to provide a kind of cross-linked polyamic acid ester, its preparation method, the preparation method of polyimide composition comprising it and polyimide resin film, to solve the problem of positive photosensitive polymerization in the prior art. The retention of photosensitive agent in imide leads to the problem of low retention rate of polyimide film.

In order to achieve the above object, according to one aspect of the present invention, a cross-linked polyamic acid ester is provided, which has structural units connected by a cross-linked structure,

Structural unit has structure shown in general formula I:

Among them, AR ₁ is a dianhydride monomer residue, AR ₂ is a diamine monomer residue, ﹋ is a linking site connected to a crosslinking structure, and n in each structural unit is independently selected from 5 to 2000 Any integer in ; the cross-linking structure -AR ₃ - is the residue of a polyphenol cross-linking agent.

In order to achieve the above object, according to one aspect of the present invention, a preparation method of cross-linked polyamic acid ester is provided, the preparation method comprising: step S1, in nitrogen or inert gas atmosphere, make diamine monomer, The dianhydride monomer is polymerized to obtain a polyamic acid precursor; step S2, the crosslinking agent, the catalyst and the polyamic acid precursor are mixed for esterification to obtain a crosslinked polyamic acid ester, and the crosslinking agent is polyphenol class of substances.

According to another aspect of the present invention, a kind of polyimide composition is provided, and this polyimide composition comprises cross-linked polyamic acid ester and photoinitiator, and cross-linked polyamic acid ester is any one of above-mentioned The cross-linked polyamic acid ester or the polyamic acid ester prepared by any one of the above-mentioned preparation methods, the photoinitiator is a photoacid generator or a photobase generator.

According to still another aspect of the present invention, a kind of preparation method of polyimide resin film is provided, and this preparation method comprises: each component of above-mentioned any one polyimide composition is mixed and then coating film and drying, obtains Dry film; expose the dry film under the protection of the mask to obtain the exposed dry film; place the exposed dry film in an alkaline developer for development to remove the dry film in the exposed area; heat the dry film It is cured to obtain a polyimide resin film.

Applying the technical scheme of the present invention, the polyphenolic cross-linking agent residue and the carboxyl residue of the original complete polyamic acid unit are used for cross-linking to form a cross-linked polyamic acid ester. The presence of the network can effectively resist the development of alkaline developer; when using it to prepare polyimide resin film, use a small amount of photoacid generator or photobase generator to generate organic strong acid or organic strong base to hydrolyze the polyamide The acid ester forms alkaline soluble polyamic acid, that is, a larger dissolution rate contrast value can be obtained in the exposed area and the non-exposed area, which ensures the retention of the polyimide resin film formed in the unexposed area, and then can form a positive Polyimide resin film with good pattern quality, good heat resistance, high resolution, high sensitivity, and high contrast.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model. In the attached picture:

Fig. 1 has shown according to embodiment of the present invention 1 polyimide resin film film thickness test result figure;

Fig. 2 shows the scanning electron microscope test result Fig. 2 of polyimide resin film according to embodiment 1 of the present invention;

Fig. 3 is a diagram showing the results of optical microscope testing of the polyimide resin film according to Example 1 of the present invention.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with examples.

As analyzed in the background technology of the present application, the retention of the photosensitive agent in the positive photosensitive polyimide of the prior art leads to the problem of low film retention rate of the polyimide film. In order to solve this problem, the application provides a cross-linked Type polyamic acid ester, its preparation method, its polyimide composition and the preparation method of polyimide resin film.

Terminology Explanation:

The residue refers to the group after removing the characteristic group. Take the residue of polyphenol crosslinking agent as an example. The body residue is the remaining group after the dianhydride is removed from the dianhydride monomer, and the AR ₂ is the diamine monomer residue is the remaining group after the diamine is removed from the diamine monomer.

In a typical embodiment of the present application, a cross-linked polyamic acid ester is provided, the cross-linked polyamic acid ester has a structural unit connected by a cross-linked structure, and the structural unit has the structure shown in the general formula I :

Wherein, AR ₁ is a dianhydride monomer residue, AR ₂ is a diamine monomer residue,

is the linking site connected with the cross-linking structure, n in each structural unit is independently selected from any integer in the range of 5 to 2000; the cross-linking structure -AR ₃ - is a residue of a polyphenol cross-linking agent.

This application utilizes polyphenolic cross-linking agent residues and carboxyl residues of the original complete polyamic acid units to carry out cross-linking to form cross-linked polyamic acid esters, which can effectively Resist the development of alkaline developer; when using it to prepare polyimide resin film, use a small amount of photoacid generator or photobase generator to generate organic strong acid or organic strong base to hydrolyze the polyamic acid ester to form alkalinity Soluble polyamic acid, that is, a larger dissolution rate contrast value can be obtained in the exposed area and the non-exposed area, which ensures the retention of the polyimide resin film formed in the unexposed area, and can form a positive pattern with good quality and durability Polyimide resin film with good thermal performance, high resolution, high sensitivity, and high contrast.

The structural units in the polyamic acid ester of the present application are formed by the polymerization of diamine monomers and dianhydride monomers, so Ar ₁ and Ar ₂ can be considered to adopt the commonly used method for preparing polyimides in this application. corresponding monomer.

In some embodiments, the aforementioned AR ₂ is selected from any one of the structures shown below,

Wherein, X ₂ and X ₃ are each independently selected from a hydrogen atom and a methyl group;

X ₄ , X ₅ and X ₆ are each independently selected from single bonds, *-O-*, *-S-*, C1-C4 alkylene groups, *-CO-*, *-COO-*, *- OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N(CH ₃ )－*, *－ Any one of CH ₂ O－*, *－C ₂ H ₄ －*, *－OCH ₂ －*, *－CONH－*, *－O－(CH ₂ ) _n －O－*, n is 1 Any integer from 5 to 5, Q ₁ and Q ₂ are selected from any one of *-CH ₃ , *-CF ₃ , *-OH, *-NH ₂ , *-Cl, *-F, preferably the X ₄ , X ₅ and X ₆ are each independently selected from a single bond, *-O-*, *-S-*, *-CH ₂ -*, *-C ₂ H ₄ -*, *-CO-*, *－COO－*, *－OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N( Any one of CH ₃ )-*, *-CH ₂ O-*, *-CONH-*, *-O-(CH ₂ ) _n -O-*, n is 3 or 4 or 5;

X ₇ and X ₈ are each independently methyl or trifluoromethyl; X ₉ is selected from any one of *-NH-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -* kind.

In some embodiments, the aforementioned AR ₂ is selected from any of the following structures:

Y ₂ to Y ₅ are each independently selected from hydrogen atoms, C ₁ to C ₅ alkyl groups, halogen atoms, substituted or unsubstituted phenyl groups, preferably Y ₂ to Y ₅ are each independently selected from hydrogen Atom, methyl, chlorine atom and phenyl any one;

Y ₆ and Y ₇ are each independently selected from hydrogen atoms, C ₁ -C ₅ alkyl groups, C ₁ -C ₅ alkyl groups substituted by halogen atoms, preferably Y ₆ and Y ₇ are each independently selected from hydrogen atoms, methyl base, trifluoromethyl;

Y ₈ is selected from single bond, *-O-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -*, *-S-*, *-C(CF ₃ ) ₂ -*, *－CH(OH)－*, *－Si(CH ₃ ) ₂ －*, *－O－(CH ₂ ) _m －O－*,

*-any one of MR ₇ R ₈ -*, m is selected from any integer from 1 to 5, R is any one of C, O, Si, S, R ₁ and R ₂ are each independently selected from Any one of empty, hydrogen atom, hydroxyl, C ₁ -C ₅ alkyl, C ₁ -C ₅ alkyl substituted by halogen atoms, preferably each of R ₁ and R ₂ is independently selected from empty, hydrogen atom, hydroxyl, methyl, trifluoromethyl, R ₃ , R ₄ are each independently selected from any of single bond, *-O-*, *-COO-*, *-CO-* One; R ₅ , R ₆ are each independently selected from any one of single bond, *-O-*, *-COO-*, *-CO-*; M is C or Si, R ₇ , R ₈ each independently selected from any one of a hydrogen atom, a methyl group, a C ₁ -C ₅ alkyl group, and a C ₁ -C ₅ alkyl group substituted by a halogen atom, preferably each of R ₇ and R ₈ is independently selected from Any one of a hydrogen atom, a methyl group, and a trifluoromethyl group.

In some embodiments, in order to improve crosslinking stability, Ar is selected from any _one of the following structural formulas:

In some embodiments, _Ar is selected from any of the following structures:

In some embodiments, in order to improve the stability of the cross-linked polyamic acid ester as much as possible, and make it easy to remove after subsequent development and exposure, it is preferred that the above AR ₃ is selected from any of the following structures:

In some embodiments of the present application, preferably, the molar ratio of the cross-linked structure to the carboxyl group in the structural unit is 2-50:50, so as to further improve the retention of the final polyimide film.

In another typical embodiment of the present application, a preparation method of cross-linked polyamic acid ester is provided, the preparation method includes: step S1, in nitrogen or inert gas atmosphere, make diamine Body, dianhydride monomers are polymerized to obtain a polyamic acid precursor; step S2, the crosslinking agent, catalyst and polyamic acid precursor are mixed for esterification to obtain a crosslinked polyamic acid ester, and the crosslinking agent is polyphenols.

The above preparation method first uses diamine monomers and dianhydride monomers to perform conventional polymerization reactions to form polyamic acid precursors; then under the action of catalysts, crosslinking agents and polyamic acids undergo esterification reactions to form crosslinking type polyamic acid ester. The polyamic acid ester forms a cross-linked network due to the bridging effect of the cross-linking agent, and the existence of the cross-linked network can effectively resist the development of an alkaline developer; when utilizing it to prepare a polyimide resin film, use a small amount of The photoacid generator or photobase generator generates organic strong acid or organic strong base to hydrolyze the polyamic acid ester to form alkaline soluble polyamic acid, that is, a larger dissolution ratio can be obtained in the exposed area and the non-exposed area , to ensure the retention of the polyimide resin film formed on the unexposed part, and then to form a polyimide resin film with good positive pattern quality, good heat resistance, high resolution, high sensitivity and high contrast.

The diamine monomers used in this application can be selected from the commonly used diamine monomers of polyimides, and _X is selected from any one of the structures shown below,

Wherein, X ₂ and X ₃ are each independently selected from a hydrogen atom and a methyl group;

X ₄ , X ₅ and X ₆ are each independently selected from single bonds, *-O-*, *-S-*, C1-C4 alkylene groups, *-CO-*, *-COO-*, *- OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N(CH ₃ )－*, *－ Any one of CH ₂ O－*, *－C ₂ H ₄ －*, *－OCH ₂ －*, *－CONH－*, *－O－(CH ₂ ) _n －O－*, n is 1 Any integer from 5 to 5, Q ₁ and Q ₂ are selected from any one of *-CH ₃ , *-CF ₃ , *-OH, *-NH ₂ , *-Cl, *-F, preferably the X ₄ , X ₅ and X ₆ are each independently selected from a single bond, *-O-*, *-S-*, *-CH ₂ -*, *-C ₂ H ₄ -*, *-CO-*, *－COO－*, *－OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N( Any one of CH ₃ )-*, *-CH ₂ O-*, *-CONH-*, *-O-(CH ₂ ) _n -O-*, n is 3 or 4 or 5;

X ₇ and X ₈ are each independently methyl or trifluoromethyl;

X ₉ is selected from any one of *-NH-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -*.

For example, diamine monomers are selected from any one or more of the following groups:

The dianhydride monomers used in this application can be selected from dianhydride monomers commonly used in polyimides. In some embodiments, the structure of the above-mentioned dianhydride monomers has the structure shown in formula III,

Wherein, Y has any _one of the following structures selected from:

Y ₂ to Y ₅ are each independently selected from hydrogen atoms, C ₁ to C ₅ alkyl groups, halogen atoms, substituted or unsubstituted phenyl groups, preferably ₂ to Y ₅ are each independently selected from hydrogen atoms Any one of , methyl, chlorine atom and phenyl;

Y ₆ and Y ₇ are each independently selected from hydrogen atoms, C ₁ -C ₅ alkyl groups, C ₁ -C ₅ alkyl groups substituted by halogen atoms, preferably Y ₆ and Y ₇ are each independently selected from hydrogen atoms, methyl base, trifluoromethyl;

Y ₈ is selected from single bond, *-O-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -*, *-S-*, *-C(CF ₃ ) ₂ -*, *－CH(OH)－*, *－Si(CH ₃ ) ₂ －*, *－O－(CH ₂ ) _m －O－*,

*-any one of MR ₇ R ₈ -*, m is selected from any integer from 1 to 5, R is any one of C, O, Si, S, R ₁ and R ₂ are each independently selected from Any one of empty, hydrogen atom, hydroxyl, C ₁ -C ₅ alkyl, C ₁ -C ₅ alkyl substituted by halogen atoms, preferably each of R ₁ and R ₂ is independently selected from empty, hydrogen atom, hydroxyl, methyl, trifluoromethyl, R ₃ , R ₄ are each independently selected from any of single bond, *-O-*, *-COO-*, *-CO-* One; R ₅ and R ₆ are each independently selected from any one of a single bond, *-O-*, *-COO-*, *-CO-*; M is C or Si, R ₇ , R ₈ each independently selected from any one of a hydrogen atom, a methyl group, a C ₁ -C ₅ alkyl group, and a C ₁ -C ₅ alkyl group substituted by a halogen atom, preferably each of R ₇ and R ₈ is independently selected from Any one of a hydrogen atom, a methyl group, and a trifluoromethyl group.

For example, the dianhydride monomer is selected from any one or more of the following compounds:

In some embodiments, in order to improve the yield of polyamic acid, preferably, the molar ratio of the above-mentioned diamine monomers to dianhydride monomers is 0.85:1˜1.05:1. The temperature of the polymerization reaction is preferably 20-40° C., and the time of the polymerization reaction is preferably 5-18 hours.

In some embodiments, the above-mentioned polymerization reaction is carried out in a homogeneous system, thereby improving the uniformity of the direct contact reaction of the monomers. For example, the polymerization reaction is carried out in an organic solvent, preferably the organic solvent is selected from N-methylpyrrolidone, N, N'-Dimethylacetamide, N,N'-Dimethylformamide, Dimethyl Sulfoxide, γ-Butyrolactone, Propylene Glycol Methyl Ether Acetate, Propylene Glycol Diacetate, Ethylene Glycol Monomethyl Ether Any one or more of the group consisting of acetate and ethylene glycol monoethyl ether acetate. The above-mentioned solvents have a high dissolving and dispersing effect on diamine monomers and dianhydride monomers, and are reactive and easy to remove. Preferably, the solid content of the obtained polyamic acid precursor is adjusted to 15-30% by adjusting the amount of the organic solvent. A polymer with suitable viscosity and molecular weight can be obtained by controlling the above solid content. The suitable viscosity and molecular weight of the polyamic acid precursor are beneficial to the subsequent esterification and crosslinking reaction and the control of the photolithography process of the polyimide composition.

When implementing the above step S1, in order to improve the mixing uniformity of the two monomers, it may be considered to first dissolve the diamine monomer in an organic solvent, and then add the dianhydride monomer.

The cross-linking agent of the present application is a polyphenolic substance. On the basis of enriching the cross-linking network as much as possible, the utilization rate of the cross-linking agent is improved. Preferably, the above-mentioned cross-linking agent is selected from any one or more of the following compounds: kind:

Most of the above-mentioned crosslinking agents are bisphenols, which have a relatively efficient esterification reaction with macromolecular polyamic acid, so the yield of polyamic acid ester is relatively high.

Within a certain range, with the increase of cross-linking agent, the yield of cross-linked polyamic acid ester is higher, but with the increase of cross-linking network, the esterification reaction of cross-linking agent and macromolecular polyamic acid The resistance increases, so that the cross-linking agent cannot fully play its role. In some embodiments, in order to improve the yield of cross-linked polyamic acid ester as much as possible and avoid waste of cross-linking agent, and avoid excess cross-linking agent residue In the final polyimide resin film, the performance of the polyimide resin film is affected, and the mol ratio of the carboxyl group in the preferred crosslinking agent and polyamic acid precursor is 2～50:100, such as 2:100, 15:100, 21:100, 35:100, 50:100, 26:100. Through the control of the molar ratio, the molar ratio of the crosslinked structure in the obtained crosslinked polyamic acid ester to the carboxyl group in the structural unit is 2-50:50.

The catalyst used to catalyze the esterification reaction of the present application can be selected from the commonly used catalysts for the esterification reaction of the prior art. In order to improve the catalytic efficiency and avoid the introduction of too many catalysts that will have an adverse effect on the final formed film layer, the preferred catalyst is 4 - Dimethylaminopyridine (DMAP) and/or diisopropylcarbodiimide (DIC). It is further preferred that the molar ratio of the catalyst to the carboxyl group in the polyamic acid precursor is 2-50:100, such as 2:100, 15:100, 31:100, 50:100, 41:100.

In order to improve the efficiency of the esterification reaction, the temperature of the above-mentioned esterification reaction is preferably -5-40° C., and the time of the esterification reaction is preferably 2-12 hours.

In another typical embodiment of the present application, a polyimide composition is provided, the polyimide composition includes a cross-linked polyamic acid ester and a photoinitiator, and the cross-linked polyamic acid ester is For any of the above-mentioned cross-linked polyamic acid esters or the polyamic acid esters prepared by any of the above-mentioned preparation methods, the photoinitiator is a photoacid generator or a photobase generator.

The cross-linked polyamic acid ester of the present application can effectively resist the development of alkaline developer due to the existence of cross-linked network; when using it to prepare polyimide resin film, use a small amount of photoacid generator or photogene Alkaline agent produces organic strong acid or organic strong base hydrolyzes the polyamic acid ester to form alkaline soluble polyamic acid, that is, a larger dissolution rate contrast value can be obtained in the exposed area and the non-exposed area, ensuring that the polyamic acid formed in the unexposed part The retention of the imide resin film can form a polyimide resin film with good positive pattern quality, good heat resistance, high resolution, high sensitivity and high contrast.

The photoinitiator that is used for this application can be selected from the photoinitiator of commonly used type at present, such as photoacid generator is selected from (5-propylsulfonyloxyimino-5H-thiophene-2-alkylene )-(2-methylphenyl)acetonitrile (PTMA), N-trifluoromethylsulfonyloxy-1,8-naphthalimide (TNI), 5-hydroxynaphthalene-1-sulfonic acid diphenyl Iodonium (DINS), Dimethyl(4,7-dihydroxynaphthalene)sulfo-p-toluenesulfonate (DDTS), Irgacure-103, Irgacure-305, Irgacure-309, N-[(4,6- Any one or more of the group consisting of dimethoxy-2-nitrobenzyl)oxy]carbonyl-2,6-dimethylpiperidine, or a photobase generator selected from thioxanthone Photobase generator TX-S-TBD, thioxanthone photobase generator TX-S-DBN, (E)-3-(2-hydroxy-4-methoxyphenyl)-1- Any one or more of the group consisting of (piperidin-1-yl)prop-2-en-1-one (HMPP). The above-mentioned photoacid generators and photobase generators have high acid or base production efficiency, so only a small amount of photoinitiator is needed to achieve efficient hydrolysis of cross-linked polyamic acid esters, thereby ensuring polyimide Amine Resin Membrane Retention.

As verified by experiments, it is preferable that the content of the photoinitiator in the polyimide composition is 2wt%-8wt%. It not only satisfies the sufficient and rapid hydrolysis of the cross-linked polyamic acid ester in the exposed part under conventional exposure and development conditions, but also avoids the excessive amount of it affecting the heat resistance and resolution of the final polyimide resin film. Rate.

In order to facilitate the construction of the polyimide composition of the present application, preferably the above polyimide composition also includes a solvent, preferably the mass content of the solvent in the polyimide composition is 70 to 85%, by controlling the amount of solvent , which not only ensures the convenience of construction of the polyimide composition, but also makes it easy to be removed in a relatively short period of time, ensuring the overall construction efficiency. In some embodiments, it is preferred that the above-mentioned solvent is selected from N-methylpyrrolidone, N,N'-dimethylacetamide, N,N'-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone , any one or more of the group consisting of propylene glycol methyl ether acetate, propylene glycol diacetate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate. The above-mentioned solvents have a high dissolving and dispersing effect on diamine monomers and dianhydride monomers, and are reactive and easy to remove. If the polyamic acid ester in the polyimide composition is obtained by the above-mentioned preparation method, the solvent in the above-mentioned composition can be the solvent added during the preparation process, or continue to add new above-mentioned organic solvents to adjust the polyimide The viscosity of the amine composition, for example, is controlled within the range of 500-20000 mPa·s. Depending on the application fields of the photoresist, the viscosity of the polyimide composition can be adjusted to form photoresists with different film thicknesses as required.

In yet another typical embodiment of the present application, a method for preparing a polyimide resin film is provided, the preparation method comprising: mixing the components of any one of the above polyimide compositions and then coating the film and drying to obtain a dry film; exposing the dry film under the protection of a mask plate to obtain a dry film after exposure; placing the dry film after exposure in an alkaline developer for development treatment to remove the dry film in the exposed area; The dry film is cured by heating to obtain a polyimide resin film.

When exposed, the cross-linked polyamic acid ester is hydrolyzed under the action of the photoinitiator to form an alkaline soluble polyamic acid, and the unexposed part of the cross-linked polyamic acid ester still exists in the form of a cross-linked network. The existence of the cross-linked network can effectively resist the development of alkaline developer, that is, a larger dissolution rate contrast value can be obtained in the exposed area and the non-exposed area, ensuring the retention of the polyimide resin film formed in the unexposed area, and then It can form a polyimide resin film with good positive pattern quality, good heat resistance, high resolution, high sensitivity and high contrast.

The positive photosensitive polyimide resin prepared by the above preparation method by means of chemical amplification has simple preparation process and mild reaction conditions. Due to the method of cross-linking first and then hydrolysis, a larger dissolution rate contrast value can be obtained between the exposed area and the non-exposed area, so the obtained photolithographic pattern is of good quality and high resolution; The yield is high, so the obtained positive pattern has the advantages of high sensitivity and high contrast.

In order to further improve the uniformity of the formed polyimide resin film, the imide composition can be subjected to membrane filtration, for example, a 0.4 μm fluororesin membrane is used for filtration, and then the above operation is performed.

The following examples and comparative examples will be used to further illustrate the beneficial effects of the present application. The following examples are only schematic illustrations of some technical solutions of the present application, and should not be construed as limiting the scope of protection of the present application.

Example 1

Under nitrogen protection, 5.0g (25.00mmoL) 4,4'-diaminodiphenyl ether was added to a 100mL three-necked round-bottomed flask, then 65.04g N-methylpyrrolidone was added thereto, mechanically stirred at room temperature, and waited for 4 , After the 4'-diaminodiphenyl ether is fully dissolved, then add 11.26g (25.35mmoL) 4,4'-(hexafluoroisopropylene) diphthalic anhydride to the solution, and mechanically stir the reaction for 12 hours at room temperature to obtain a highly viscous polyamic acid precursor.

Get 10g of the above-mentioned highly viscous polyamic acid precursor in a round-bottomed flask, add 0.33g 4,4'-methylenebis(2,6-xylenol) to it under ice-bath conditions, and wait for 4, After 4'-methylenebis(2,6-xylenol) was fully dissolved in polyamic acid, 0.12 g of catalyst 4-dimethylaminopyridine (DMAP) and catalyst diisopropylcarbodiimide ( DIC) 0.12g, remove the ice bath, and react at room temperature for 5h to obtain polyamic acid ester.

The polyamic acid ester of above-mentioned gain gets 8g and is placed in the round bottom flask, then adds photoacid generator (5-propyl group sulfonyloxyimino group-5H-thiophene-2-alkylene group)-(2 - 0.30 g of methylphenyl) acetonitrile (PTMA), stirred at room temperature for 2 h to form a homogeneous solution, and passed through a 0.40 μm fluororesin film to obtain a positive photosensitive polyimide composition solution. The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 1212.8 mPa·s.

Example 2

In the above example 1, the diamine monomer 4,4'-diaminodiphenyl ether was replaced with 4,4'-diaminodiphenylmethane, and the amount of the organic solvent N-methylpyrrolidone was changed to 92.76g, 4,4 The amount of '-methylene bis(2,6-xylenol) is changed to 0.63g, and the amount of DMAP and DIC is changed to 0.152g, and other steps are the same as in Example 1, and the positive polarity is recorded by a rotational viscometer. The viscosity of the solution of the photosensitive polyimide composition was 595.6 mPa·s.

Example 3

In the above-mentioned embodiment 1, the dianhydride monomer 4,4'-(hexafluoroisopropylene) diphthalic anhydride was replaced with diphenyl ether tetraacid dianhydride, and the amount of the organic solvent N-methylpyrrolidone was changed to 51.76g, 4, The amount of 4'-methylene bis(2,6-xylenol) is changed to 0.023g, and the amount of DMAP and DIC is changed to 6.0mg. Other steps are the same as in Example 1, and the positiveness is measured by a rotational viscometer. The viscosity of the solution of the photosensitive polyimide composition was 3248.7 mPa·s.

Example 4

Under nitrogen protection, 5.0g (25.00mmoL) 4,4'-diaminodiphenyl ether was added to a 100mL three-necked round-bottomed flask, then 65.04g N-methylpyrrolidone was added thereto, mechanically stirred at room temperature, and waited for 4 , After the 4'-diaminodiphenyl ether is fully dissolved, then add 11.26g (25.35mmoL) 4,4'-(hexafluoroisopropene) diphthalic anhydride to the solution, and mechanically stir the reaction for 15 hours at room temperature to obtain a highly viscous polyamic acid precursor.

Take 10g of the above-mentioned highly viscous polyamic acid precursor in a round-bottomed flask, add 0.44g 4,4'-dihydroxydiphenylmethane to it under ice-bath conditions, and treat 4,4'-dihydroxydiphenylmethane After methyl methane is fully dissolved in polyamic acid, then add 0.12 g of catalyst 4-dimethylaminopyridine (DMAP) and 0.12 g of catalyst diisopropylcarbodiimide (DIC) in sequence, remove the ice bath, and react at room temperature for 8 h. Polyamic acid ester was obtained.

The polyamic acid ester of above-mentioned gain gets 8g and is placed in the round bottom flask, then adds photoacid generator (5-propyl group sulfonyloxyimino group-5H-thiophene-2-alkylene group)-(2 - 0.35 g of methylphenyl) acetonitrile (PTMA), stirred at room temperature for 3 h to form a homogeneous solution, and passed through a 0.40 μm fluororesin film to obtain a positive photosensitive polyimide composition solution. The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 11217.5 mPa·s.

Example 5

The content of the catalyst DMAP in the above-mentioned embodiment 4 is changed to 0.16g, and the content of the catalyst DIC is changed to 0.16g, and other steps are the same as in Example 4, and the positive photosensitive polyimide composition solution is measured by a rotational viscometer. The viscosity is 18911.4mPa·s.

Example 6

Under nitrogen protection, 5.0g (25.00mmoL) 4,4'-diaminodiphenyl ether was added to a 100mL three-necked round-bottomed flask, then 65.04g N-methylpyrrolidone was added thereto, mechanically stirred at room temperature, and waited for 4 , After the 4'-diaminodiphenyl ether is fully dissolved, then add 11.26g (25.35mmoL) 4,4'-(hexafluoroisopropylene) diphthalic anhydride to the solution, and mechanically stir the reaction for 10 hours at room temperature to obtain a highly viscous polyamic acid precursor.

Get 10g of the above-mentioned highly viscous polyamic acid precursor in a round-bottomed flask, add 0.33g 4,4'-methylenebis(2,6-xylenol) to it under ice-bath conditions, and wait for 4, After 4'-methylenebis(2,6-xylenol) was fully dissolved in polyamic acid, 58 mg of catalyst 4-dimethylaminopyridine (DMAP) and catalyst diisopropylcarbodiimide (DIC ) 58mg, remove the ice bath, and react at room temperature for 4h to obtain polyamic acid ester.

The polyamic acid ester of above-mentioned gain is got 8g and is placed in the round-bottomed flask, then adds photoacid generator N-trifluoromethylsulfonyloxy group-1,8-naphthalimide (TNI) 0.30g wherein, Stir at room temperature for 3 hours to form a homogeneous solution, pass through a 0.40 μm fluororesin film to obtain a positive photosensitive polyimide composition solution. The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 8197.8 mPa·s.

Example 7

In the above-mentioned embodiment 6, the photoacid generator N-trifluoromethylsulfonyloxy-1,8-naphthalimide (TNI) is replaced by the photobase generator thioxanthone photobase generator TX-S-DBN, the content was changed to 0.40g, and the other steps were the same as in Example 6. The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 1227.6mPa·s.

Example 8

Under nitrogen protection, 5.0g (25.00mmoL) 4,4'-diaminodiphenyl ether was added to a 100mL three-necked round-bottomed flask, then 65.04g N-methylpyrrolidone was added thereto, mechanically stirred at room temperature, and waited for 4 , After the 4'-diaminodiphenyl ether is fully dissolved, then add 11.26g (25.35mmoL) 4,4'-(hexafluoroisopropylene) diphthalic anhydride to the solution, and mechanically stir the reaction for 10 hours at room temperature to obtain a highly viscous polyamic acid precursor.

Get 10g of the above-mentioned highly viscous polyamic acid precursor in a round-bottomed flask, add 0.33g 4,4'-methylenebis(2,6-xylenol) to it under ice-bath conditions, and wait for 4, After 4'-methylenebis(2,6-xylenol) was fully dissolved in polyamic acid, 0.12 g of catalyst 4-dimethylaminopyridine (DMAP) and catalyst diisopropylcarbodiimide ( DIC) 0.12g, remove the ice bath, and react at room temperature for 5h to obtain polyamic acid ester.

The polyamic acid ester of above-mentioned gain gets 8g and is placed in the round bottom flask, then adds photobase generator (E)-3-(2-hydroxyl-4-methoxyphenyl)-1-(piperidine -1-yl)prop-2-en-1-one 0.30g, stirred at room temperature for 2h to form a homogeneous solution, and obtained a positive photosensitive polyimide composition solution after passing through a 0.40 μm fluororesin film . The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 3241.8 mPa·s.

Comparative example 1

Under nitrogen protection, 5.0g (25.00mmoL) 4,4'-diaminodiphenyl ether was added to a 100mL three-necked round-bottomed flask, then 65.04g N-methylpyrrolidone was added thereto, mechanically stirred at room temperature, and waited for 4 , After the 4'-diaminodiphenyl ether is fully dissolved, then add 11.26g (25.35mmoL) 4,4'-(hexafluoroisopropylene) diphthalic anhydride to the solution, and mechanically stir the reaction for 12 hours at room temperature to obtain a highly viscous polyamic acid precursor.

Get 10g of the above-mentioned highly viscous polyamic acid precursor in a round-bottomed flask, add 1.20g 4,4'-methylenebis(2,6-xylenol) to it under ice-bath conditions, and wait for 4, After 4'-methylenebis(2,6-xylenol) was fully dissolved in polyamic acid, 0.30 g of catalyst 4-dimethylaminopyridine (DMAP) and catalyst diisopropylcarbodiimide ( DIC) 0.30g, remove the ice bath, and react at room temperature for 4h to obtain polyamic acid ester.

The polyamic acid ester of above-mentioned gain gets 8g and is placed in the round bottom flask, then adds photoacid generator (5-propyl group sulfonyloxyimino group-5H-thiophene-2-alkylene group)-(2 - 0.50 g of methylphenyl) acetonitrile (PTMA), stirred at room temperature for 2 h to form a homogeneous solution, and passed through a 0.40 μm fluororesin film to obtain a positive photosensitive polyimide composition solution. The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 1224.5 mPa·s.

Comparative example 2

In Example 1, the catalyst 4-dimethylaminopyridine (DMAP) was changed to 5.0 mg, and diisopropylcarbodiimide (DIC) was changed to 5.0 mg, and other steps were the same as in Example 1. The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 1158.9 mPa·s.

Comparative example 3

In Example 1, 4,4'-methylenebis(2,6-xylenol) was changed to 0.020 g, and the other steps were the same as in Example 1. The viscosity of the positive photosensitive polyimide composition solution measured by a rotational viscometer was 758.9 mPa·s.

Below the positive photosensitive polyimide composition solutions of above-mentioned 8 kinds of embodiments and 3 kinds of comparative examples are processed as follows:

Coating: Spin coating the solution of the positive photosensitive polyimide composition on the surface of the silicon wafer by spin coating;

Pre-baking: remove most of the organic solvent on the surface to form a cured layer film;

Exposure: Use G-25X photolithography machine to expose under ultraviolet light (i line);

Developing: place the exposed silicon wafer in an alkaline aqueous developer solution of 2.38% tetramethylammonium hydroxide alkaline aqueous solution, develop to remove the exposed area, leave the pattern of the unexposed area, and wash it with water;

Complete curing: use temperature programming to heat the above pattern to 300°C for 1 hour to form a polyimide resin film.

The formed polyimide resin film was tested by the following method.

Film thickness test: adopt step meter (KLA Dektak XT) to test polyimide resin film film thickness, wherein, the test result of embodiment 1 is shown in Fig. 1, and scanning electron microscope (JOEL JCM-6000Plus) test result is shown in Fig. 2, optical The microscope test results are shown in Figure 3. It can be seen from Figure 1 that the thickness of the photoresist film is about 3 microns, the side wall is steep, and the film surface is very flat; Thorough; from Figure 3, it can be seen that the photolithography pattern of the whole piece is very regular and neat, no matter whether it is made of pillars or dug holes.

5% weight loss temperature test: tested by Shimadzu TGA 50H thermogravimetric analyzer. The nitrogen flow rate is 100mL/min, the heating rate is 10°C/min, and the heating range is from room temperature to 600°C.

Sensitivity and contrast test: spin-coat the positive photosensitive polyimide composition solution on the surface of the silicon wafer, place it under ultraviolet (i line) exposure after pre-baking, make the curve of exposure dose and normalized film thickness, by normalization The normalized curves were used to obtain photosensitivity and contrast.

Resolution test: The resolution of the resulting pattern was observed under a scanning electron microscope.

The thermal performance and photolithography performance of each embodiment and comparative example are shown in Table 1 below.

Table 1

In the above table: ODA: 4,4'-diaminodiphenyl ether; 6FDA: 4,4'-(hexafluoroisopropene) diphthalic anhydride; MDA: 4,4'-diaminodiphenylmethane; OPDA: two Phenyl ether tetra-acid dianhydride; 4-MBDP: 4,4'-methylenebis(2,6-xylenol); BPF: 4,4'-dihydroxydiphenylmethane; 4-TTPM: 4,4 ',4"-methylenetriphenol; PTMA: (5-propylsulfonyloxyimino-5H-thiophene-2-alkylene)-(2-methylphenyl)acetonitrile; TNI: N- Trifluoromethylsulfonyloxy-1,8-naphthalimide; TX-S-DBN: thioxanthone photobase generator TX-S-DBN; HMPP: (E)-3-(2 -Hydroxy-4-methoxyphenyl)-1-(piperidin-1-yl)prop-2-en-1-one.

From the above description, it can be seen that the polyphenolic cross-linking agent residue and the carboxyl residue of the original complete polyamic acid unit are used for cross-linking to form a cross-linked polyamic acid ester. Due to the existence of the cross-linked network, it can effectively resist the development of alkaline developer; when using it to prepare polyimide resin film, use a small amount of photoacid generator or photobase generator to produce organic strong acid or organic strong base hydrolysis The polyamic acid ester forms an alkaline soluble polyamic acid, that is, a larger dissolution rate contrast value can be obtained in the exposed area and the non-exposed area, which ensures the retention of the polyimide resin film formed in the unexposed area, and then can Form a polyimide resin film with good positive pattern quality, good heat resistance, high resolution, high sensitivity and high contrast.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A kind of cross-linked polyamic acid ester, it is characterized in that, described cross-linked polyamic acid ester has the structural unit connected by cross-linked structure,

   The structural unit has a structure shown in general formula I:

   

   Wherein, AR ₁ is a dianhydride monomer residue, AR ₂ is a diamine monomer residue,

   

   is a connection site connected to the cross-linking structure, and n in each of the structural units is independently selected from any integer in the range of 5 to 2000;

   The cross-linking structure -AR ₃ - is a polyphenol cross-linking agent residue.
2. Cross-linked polyamic acid ester according to claim 1, is characterized in that, described AR ₂ is selected from any one of the structures shown below,

   

   Wherein, X ₂ and X ₃ are each independently selected from a hydrogen atom and a methyl group;

   X ₄ , X ₅ and X ₆ are each independently selected from single bonds, *-O-*, *-S-*, C1-C4 alkylene groups, *-CO-*, *-COO-*, *- OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N(CH ₃ )－*, *－ Any one of CH ₂ O－*, *－C ₂ H ₄ －*, *－OCH ₂ －*, *－CONH－*, *－O－(CH ₂ ) _n －O－*, n is 1 Any integer from 5 to 5, Q ₁ and Q ₂ are selected from any one of *-CH ₃ , *-CF ₃ , *-OH, *-NH ₂ , *-Cl, *-F, preferably the X ₄ , X ₅ and X ₆ are each independently selected from a single bond, *-O-*, *-S-*, *-CH ₂ -*, *-C ₂ H ₄ -*, *-CO-*, *－COO－*, *－OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N( Any one of CH ₃ )-*, *-CH ₂ O-*, *-CONH-*, *-O-(CH ₂ ) _n -O-*, n is 3 or 4 or 5;

   X ₇ and X ₈ are each independently methyl or trifluoromethyl;

   X ₉ is selected from any one of *-NH-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -*.

   Preferably, the _Ar is selected from any one of the following structural formulas:

   

   And/or, the AR ₂ is selected from any one of the following structures:

   

   Y ₂ to Y ₅ are each independently selected from hydrogen atoms, C ₁ to C ₅ alkyl groups, halogen atoms, substituted or unsubstituted phenyl groups, preferably ₂ to Y ₅ are each independently selected from hydrogen atoms Any one of , methyl, chlorine atom and phenyl;

   Y ₆ and Y ₇ are each independently selected from hydrogen atoms, C ₁ -C ₅ alkyl groups, C ₁ -C ₅ alkyl groups substituted by halogen atoms, preferably Y ₆ and Y ₇ are each independently selected from hydrogen atoms, methyl base, trifluoromethyl;

   Y ₈ is selected from single bond, *-O-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -*, *-S-*, *-C(CF ₃ ) ₂ -*, *－CH(OH)－*, *－Si(CH ₃ ) ₂ －*, *－O－(CH ₂ ) _m －O－*,

   

   *-any one of MR ₇ R ₈ -*, m is selected from any integer from 1 to 5, R is any one of C, O, Si, S, R ₁ and R ₂ are each independently selected from Any one of empty, hydrogen atom, hydroxyl, C ₁ -C ₅ alkyl, C ₁ -C ₅ alkyl substituted by halogen atoms, preferably each of R ₁ and R ₂ is independently selected from empty, hydrogen atom, hydroxyl, methyl, trifluoromethyl, R ₃ , R ₄ are each independently selected from any of single bond, *-O-*, *-COO-*, *-CO-* One; R ₅ and R ₆ are each independently selected from any one of a single bond, *-O-*, *-COO-*, *-CO-*; M is C or Si, R ₇ , R ₈ each independently selected from any one of a hydrogen atom, a methyl group, a C ₁ -C ₅ alkyl group, and a C ₁ -C ₅ alkyl group substituted by a halogen atom, preferably each of R ₇ and R ₈ is independently selected from Any one of hydrogen atom, methyl group and trifluoromethyl group;

   Preferably the _Ar is selected from any one of the following structures:

   

   And/or, the AR ₃ is selected from any one of the following structures:

   

   And/or the molar ratio of the cross-linked structure to the carboxyl group in the structural unit is 2-50:50.
3. A kind of preparation method of cross-linked polyamic acid ester, it is characterized in that, described preparation method comprises:

   Step S1, in a nitrogen or inert gas atmosphere, polymerize diamine monomers and dianhydride monomers to obtain polyamic acid precursors;

   Step S2, mixing a cross-linking agent, a catalyst, and the polyamic acid precursor for esterification to obtain the cross-linked polyamic acid ester, and the cross-linking agent is a polyphenolic substance.
4. The preparation method according to claim 3, wherein the diamine monomer has a general structural formula shown in formula II,

   

   Wherein, _X is selected from any one of the structures shown below,

   

   Wherein, X ₂ and X ₃ are each independently selected from a hydrogen atom and a methyl group;

   X ₄ , X ₅ and X ₆ are each independently selected from single bonds, *-O-*, *-S-*, C1-C4 alkylene groups, *-CO-*, *-COO-*, *- OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N(CH ₃ )－*, *－ Any one of CH ₂ O－*, *－C ₂ H ₄ －*, *－OCH ₂ －*, *－CONH－*, *－O－(CH ₂ ) _n －O－*, n is 1 Any integer from 5 to 5, Q ₁ and Q ₂ are selected from any one of *-CH ₃ , *-CF ₃ , *-OH, *-NH ₂ , *-Cl, *-F, preferably the X ₄ , X ₅ and X ₆ are each independently selected from a single bond, *-O-*, *-S-*, *-CH ₂ -*, *-C ₂ H ₄ -*, *-CO-*, *－COO－*, *－OC(O)－*, *－SO ₂ －*, *－CF ₂ －*, *－C(CF ₃ ) ₂ －*, *－NH－*, *－N( Any one of CH ₃ )-*, *-CH ₂ O-*, *-CONH-*, *-O-(CH ₂ ) _n -O-*, n is 3 or 4 or 5;

   X ₇ and X ₈ are each independently methyl or trifluoromethyl;

   X ₉ is selected from any one of *-NH-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -*;

   Further preferably, the diamine monomer is any one or more selected from the group consisting of the following substances,

   

   

   

   And/or, the dianhydride monomer structure has a structure shown in formula III,

   

   Wherein, Y has any _one of the following structures selected from:

   

   Y ₂ to Y ₅ are each independently selected from hydrogen atoms, C ₁ to C ₅ alkyl groups, halogen atoms, substituted or unsubstituted phenyl groups, preferably ₂ to Y ₅ are each independently selected from hydrogen atoms Any one of , methyl, chlorine atom and phenyl;

   Y ₆ and Y ₇ are each independently selected from hydrogen atoms, C ₁ -C ₅ alkyl groups, C ₁ -C ₅ alkyl groups substituted by halogen atoms, preferably Y ₆ and Y ₇ are each independently selected from hydrogen atoms, methyl base, trifluoromethyl;

   Y ₈ is selected from single bond, *-O-*, *-CH ₂ -*, *-CO-*, *-SO ₂ -*, *-S-*, *-C(CF ₃ ) ₂ -*, *－CH(OH)－*, *－Si(CH ₃ ) ₂ －*, *－O－(CH ₂ ) _m －O－*,

   

   *-any one of MR ₇ R ₈ -*, m is selected from any integer from 1 to 5, R is any one of C, O, Si, S, R ₁ and R ₂ are each independently selected from Any one of empty, hydrogen atom, hydroxyl, C ₁ -C ₅ alkyl, C ₁ -C ₅ alkyl substituted by halogen atoms, preferably each of R ₁ and R ₂ is independently selected from empty, hydrogen atom, hydroxyl, methyl, trifluoromethyl, R ₃ , R ₄ are each independently selected from any of single bond, *-O-*, *-COO-*, *-CO-* One; R ₅ and R ₆ are each independently selected from any one of a single bond, *-O-*, *-COO-*, *-CO-*; M is C or Si, R ₇ , R ₈ each independently selected from any one of a hydrogen atom, a methyl group, a C ₁ -C ₅ alkyl group, and a C ₁ -C ₅ alkyl group substituted by a halogen atom, preferably each of R ₇ and R ₈ is independently selected from Any one of hydrogen atom, methyl group and trifluoromethyl group;

   It is further preferred that the dianhydride monomer is selected from any one or more of the following compounds,

   

   

   

   Preferably, the molar ratio of the diamine monomer to the dianhydride monomer is 0.80:1 to 1.2:1, and the polymerization reaction is preferably carried out in an organic solvent, preferably the organic solvent is selected from N-methyl Pyrrolidone, N,N'-dimethylacetamide, N,N'-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, propylene glycol methyl ether acetate, propylene glycol diacetate, ethylene glycol Any one or more of the group consisting of alcohol monomethyl ether acetate and ethylene glycol monoethyl ether acetate.
5. The preparation method according to claim 3 or 4, wherein the crosslinking agent is selected from any one or more of the following compounds:

   

   

   Preferably, the molar ratio of the crosslinking agent to the carboxyl group in the polyamic acid precursor is 2 to 50:100;

   Preferably said catalyst is 4-dimethylaminopyridine and/or diisopropylcarbodiimide,

   Preferably, the molar ratio of the catalyst to the carboxyl group in the polyamic acid precursor is 2-50:100.
6. A kind of polyimide composition, it is characterized in that, described polyimide composition comprises cross-linked polyamic acid ester and photoinitiator, and described cross-linked polyamic acid ester is described in claim 1 or 2 The cross-linked polyamic acid ester or the polyamic acid ester prepared by the preparation method described in any one of claims 3 to 5, the photoinitiator is a photoacid generator or a photobase generator.
7. The polyimide composition according to claim 6, wherein the photoacid generator is selected from (5-propylsulfonyloxyimino-5H-thiophene-2-alkylene)- (2-methylphenyl)acetonitrile, N-trifluoromethylsulfonyloxy-1,8-naphthalimide, 5-hydroxynaphthalene-1-sulfonic acid diphenyliodonium, dimethyl(4 ,7-dihydroxynaphthalene)sulfo-p-toluenesulfonate, Irgacure-103, Irgacure-305, Irgacure-309, N-[(4,6-dimethoxy-2-nitrobenzyl)oxy ] any one or more of the group consisting of carbonyl-2,6-dimethylpiperidine, or the photobase generator is selected from thioxanthone photobase generators TX-S-TBD, Thioxanthone photobase generators TX-S-DBN, (E)-3-(2-hydroxy-4-methoxyphenyl)-1-(piperidin-1-yl)propan-2- Any one or more of the group consisting of en-1-ones.
8. The polyimide composition according to claim 6 or 7, characterized in that the content of the photoinitiator in the polyimide composition is 2wt%˜8wt%.
9. The polyimide composition according to any one of claims 6 to 8, wherein the polyimide composition also includes a solvent, preferably the polyimide composition of the solvent described in the polyimide composition The mass content is 70% to 85%; preferably, the solvent is selected from N-methylpyrrolidone, N,N'-dimethylacetamide, N,N'-dimethylformamide, dimethyl sulfoxide, γ - any one or more of the group consisting of butyrolactone, propylene glycol methyl ether acetate, propylene glycol diacetate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.
10. A kind of preparation method of polyimide resin film, it is characterized in that, described preparation method comprises:

    After mixing the components of the polyimide composition according to any one of claims 6 to 9, the film is applied and dried to obtain a dry film;

    Expose the dry film under the protection of a mask to obtain a dry film after exposure;

    placing the exposed dry film in an alkaline developer for development to remove the dry film in the exposed area;

    The dry film is heated and cured to obtain a polyimide resin film.

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