Negative photosensitive polyimide material with micropores as well as preparation method and application of negative photosensitive polyimide material

Abstract

The invention provides a negative photosensitive polyimide material with micropores as well as a preparation method and application of the negative photosensitive polyimide material. The negative photosensitive polyimide material with the micropores has a structure as shown in a formula I. The polyimide with a main chain containing benzophenone and alkyl is prepared by using an imide ring-containing diamine monomer, the polyimide is easily dissolved in an organic reagent, and after spin coating, crosslinking can be generated in an exposed area without adding any small-molecule auxiliary agent, and a remarkable solubility difference is formed between the polyimide and an unexposed area. In addition, the polymer for exposure is completely imidized, and only small molecules need to be removed at low temperature in subsequent treatment, so that the problems caused by high-temperature thermal imidization are avoided. The exposure required by complete crosslinking of the negative photosensitive polyimide with the micropores theoretically is 250-900mJ / cm < 2 >, and the negative photosensitive polyimide with the micropores has a wide application prospect in the high-end fields of photoresist for integrated circuits, OLED display panels and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyimide materials, and particularly relates to a self-microporous negative photosensitive polyimide material, a preparation method thereof, and an application thereof. Background Art

[0002] As the integrated circuit (IC) manufacturing process enters the nanoscale, the progress of the lithography process has increasingly stringent requirements for material properties. Although traditional polyimide (PI) has excellent high-temperature resistance (>400°C), low dielectric constant (~3.0), and strong mechanical strength, it relies on other types of photoresists for patterning, with cumbersome steps and easy introduction of defects. Photosensitive polyimide (PSPI) introduces photosensitive groups into the polyimide molecular chain and directly realizes patterning through ultraviolet exposure, reducing process steps and avoiding interface problems between multiple layers of materials.

[0003] Currently, most negative PSPI requires the addition of photoinitiators to enhance photosensitivity, while the photosensitive additives may decompose in high-temperature / high-humidity environments, resulting in degradation of the insulation performance of photosensitive PSPI or a decrease in interfacial adhesion. In addition, the current negative PSPI generally has a relatively high curing temperature and requires a high temperature of 250-400°C for post-baking to achieve imidization, which has relatively high requirements for the heat resistance of the substrate. And in large-area applications, polymer shrinkage at high temperatures may lead to stress accumulation, causing film cracking or substrate warping.

[0004] In this application, by introducing benzophenone and methyl structures into diamine and dianhydride monomers, an intrinsic negative PSPI is synthesized. Under ultraviolet light irradiation, without the addition of photoinitiators, cross-linking reactions occur between benzophenone and methyl, resulting in a solubility difference of the intrinsic negative PSPI before and after light irradiation. In addition, by introducing a V-shaped rigid twisted chiral base structure into diamine and dianhydride containing benzophenone structures and methyl, due to the formation of a self-microporous structure, it has a higher solubility compared to conventional polyimide, which can increase the solubility difference before and after exposure and improve the quality of the later lithography pattern; it belongs to a formed PSPI, different from most commercial PSPI that requires post-baking dehydration of the precursor, and can avoid film shrinkage during this process; thus, the temperature required during post-baking is relatively low, and only the residual developer and solvent attached to the surface need to be removed.

[0005] Due to its unique structure and synthesis route, the self-microporous negative photosensitive polyimide is different from the current mainstream PSPI preparation process, and still has great development space in terms of performance improvement and mechanism exploration. Driven by technological upgrading and industrial demands, as well as strategic value and economic impact, it is expected to be widely used in the field of electronic packaging. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a self-porous negative photosensitive polyimide material, its preparation method and application. The self-porous negative photosensitive polyimide obtained by introducing benzophenone, methyl and Chauger base structure has important application value in the fields of photoresist and electronic packaging.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a self-porous negative photosensitive polyimide material, and the self-porous negative photosensitive polyimide has the structure shown in Formula I:

[0009]

[0010] Among them, Ar1 is an aromatic or alicyclic dianhydride residue containing a carbonyl group or an alkyl group structure, and Ar2 is an aromatic diamine residue containing a carbonyl group or an alkyl group structure; and Ar1 and Ar2 are not simultaneously structures containing a carbonyl group;

[0011] n is an integer from 100 to 10,000, for example, it can be 100, 200, 300, 500, 1000, 2000, 5000, 8000, 9000, 10,000, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the scope.

[0012] The self-porous negative photosensitive polyimide provided by the present invention has benzophenone and methyl structures, and can undergo a cross-linking reaction under ultraviolet light irradiation without the need to add additional additives such as photoinitiators, and can keep the polymer having excellent thermal, mechanical and electrical properties. In addition, the Chauger base introduced into the structure has a polar group and a rigid twisted structure, which can increase the solubility of the polymer in polar solvents through the action of polar groups, steric hindrance effects and the inhibition of intermolecular forces, thereby increasing the solubility difference before and after exposure and improving the quality of the later photolithography pattern. The post-baking temperature after ultraviolet cross-linking of the formed polyimide is relatively low, avoiding a series of problems such as shrinkage of the polymer film caused by high-temperature post-baking dehydration curing required for traditional photosensitive polyimides after ultraviolet cross-linking.

[0013] The aromatic or alicyclic dianhydride residue described in the present invention refers to the group remaining after removing the anhydride group from the aromatic or alicyclic dianhydride. The aromatic diamine residue described in the present invention refers to the group remaining after removing the two terminal amino groups and the Chauger base from the aromatic diamine.

[0014] Preferably, when Ar1 contains a carbonyl structure, Ar2 is an aromatic diamine residue containing an alkyl group structure; when Ar2 contains a carbonyl structure, Ar1 is an aromatic or alicyclic dianhydride residue containing an alkyl group structure.

[0015] Preferably, when Ar1 contains a carbonyl structure, Ar2 has the following substituted or unsubstituted structure:

[0016]

[0017] Wherein, X is a straight-chain or branched-chain alkyl group having 1 to 16 carbon atoms or a cycloalkyl group having 3 to 16 carbon atoms;

[0018] Y1 to Y 15 are each independently selected from the group consisting of H, a straight-chain or branched-chain alkyl group having 1 to 16 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, an amino group, a dimethylamino group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonyl group, a mercapto group, a methoxy group, an aldehyde group, and a halogen atom;

[0019] The dotted line represents the connection site of the group.

[0020] Preferably, when Ar1 is a structure containing a carbonyl group, the structure containing a carbonyl group includes:

[0021]

[0022] The dotted line represents the connection site of the group.

[0023] Preferably, when Ar2 is a structure containing a carbonyl group, Ar1 has an alkyl-substituted structure.

[0024] Preferably, when Ar2 is a structure containing a carbonyl group, Ar1 includes the following structures:

[0025]

[0026] Wherein m is an integer from 2 to 5 (such as 2, 3, 4, or 5), and the dotted line represents the connection site of the group. Preferably, when Ar2 is a structure containing a carbonyl group, the structure containing a carbonyl group includes:

[0027]

[0028] The dotted line represents the connection site of the group.

[0029] Preferably, the weight-average molecular weight of the self-microporous negative photosensitive polyimide is 50,000 to 1,000,000, for example, it can be 50,000, 60,000, 80,000, 100,000, 200,000, 500,000, 800,000, 900,000, 1,000,000, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0030] In a second aspect, the present invention provides a method for preparing the self-microporous negative photosensitive polyimide as described in the first aspect, characterized in that the preparation method includes:

[0031] (1) React an aromatic or alicyclic dianhydride A with an aromatic diamine B to obtain a diamino monomer containing amide groups.

[0032] (2) React the diamino monomer containing amide groups with a formaldehyde source to obtain the self - microporous negative photosensitive polyimide.

[0033] The diamine monomer containing amide groups has the structure shown in Formula II:

[0034]

[0035] Wherein R1 is an aromatic or alicyclic dianhydride residue; R2 is an aromatic diamine residue.

[0036] The self - microporous negative photosensitive polyimide has the structure shown in Formula I.

[0037]

[0038] When the aromatic or alicyclic dianhydride A contains a carbonyl structure, preferably, the aromatic diamine B has the following structure:

[0039]

[0040] X is a straight - chain or branched - chain alkyl group with 1 to 16 carbon atoms or a cycloalkyl group with 3 to 16 carbon atoms.

[0041] Z1 to Z 15 Are each independently selected from the group consisting of H, a straight - chain or branched - chain alkyl group with 1 to 16 carbon atoms, a cycloalkyl group with 3 to 16 carbon atoms, an amino group, a dimethylamino group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonyl group, a mercapto group, a methoxy group, an aldehyde group, and a halogen atom.

[0042] Preferably, when A is a structure containing a carbonyl group, the structure containing a carbonyl group includes:

[0043]

[0044] Preferably, when the aromatic diamine B contains a carbonyl structure, the aromatic or alicyclic dianhydride A has the following structure:

[0045]

[0046] Preferably, when B is a structure containing a carbonyl group, the structure containing a carbonyl group includes:

[0047]

[0048] Preferably, the weight-average molecular weight of the self-microporous negative photosensitive polyimide is 50,000 to 1,000,000, and can be, for example, 50,000, 60,000, 80,000, 100,000, 200,000, 500,000, 800,000, 900,000, 1,000,000, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0049] Preferably, the molar ratio of the aromatic or alicyclic dianhydride A to the aromatic diamine B in step (1) is (1 to 1.05):3, and can be, for example, 1:3, 1.01:3, 1.02:3, 1.03:3, 1.04:3, 1.05:3, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0050] Preferably, the reaction in step (1) is carried out in the presence of a solvent.

[0051] Preferably, the solvent includes a high-boiling solvent.

[0052] Preferably, the high-boiling polar solvent includes any one or at least two combinations of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol or dimethyl sulfoxide.

[0053] Preferably, the temperature of the reaction in step (1) is 0 to 10 °C, and can be, for example, 0 °C, 1 °C, 2 °C, 5 °C, 8 °C, 9 °C, 10 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0054] Preferably, the reaction time in step (1) is 6 to 24 h, and can be, for example, 6 h, 7 h, 8 h, 9 h, 10 h, 12 h, 15 h, 18 h, 20 h, 21 h, 24 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0055] Preferably, after the reaction in step (1) is completed, a water-carrying agent is added for a secondary reaction and purification to obtain the diamine monomer containing an amide group.

[0056] Preferably, the water-carrying agent includes any one or at least two combinations of toluene, xylene or chlorobenzene.

[0057] Preferably, the temperature of the secondary reaction is 150-200 °C, for example, it can be 150 °C, 155 °C, 160 °C, 165 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 195 °C, 200 °C, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0058] Preferably, the time of the secondary reaction is 2-80 h, for example, it can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h, 45 h, 50 h, 55 h, 60 h, 65 h, 70 h, 75 h, 80 h, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0059] Preferably, the purification includes evaporating the water-carrying agent, pouring the reaction solution into a mixed solution of methanol and water to precipitate a solid product, then redissolving it, pouring it into ethanol to precipitate, filtering, and drying to obtain a diamine monomer containing an amide group.

[0060] Preferably, the solvent used for redissolving is selected from one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, chloroform, dichloromethane, or acetone.

[0061] Preferably, the formaldehyde source agent in step (2) includes any one or a combination of at least two of formaldehyde, paraformaldehyde, hexamethylenetetramine, dimethoxymethane, or ethylene glycol dimethyl ether.

[0062] Preferably, the reaction in step (2) is carried out in an acidic solvent.

[0063] Preferably, the pH value of the acidic solvent is 0.5-6, for example, it can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0064] Preferably, the acidic solvent includes any one or a combination of at least two of trifluoroacetic acid, polyphosphoric acid, formic acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, or hydrochloric acid.

[0065] Preferably, after mixing the diamine monomer containing an amide group with the formaldehyde source agent, a solvent is added for reaction.

[0066] Preferably, the molar ratio of the diamine monomer containing an amide group to the formaldehyde source in step (2) is 4-10:1, such as 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 8:1, 9:1 or 10:1.

[0067] Preferably, the mixing temperature is -5 to 30 °C, such as -5 °C, 0 °C, 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range; the reaction temperature is -20 to 50 °C, such as -20 °C, -10 °C, 0 °C, 10 °C, 20 °C, 30 °C, 40 °C, 50 °C, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0068] Preferably, the reaction time in step (2) is 24-240 h, such as 24 h, 48 h, 72 h, 96 h, 120 h, 144 h, 168 h, 192 h, 216 h, 240 h, and specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0069] Preferably, after the reaction in step (2) is completed, an alkali solution is added to the reaction solution to precipitate a fibrous or powdery solid product. The obtained fibrous or powdery solid product is redissolved, poured into a second solvent, precipitated, washed, and dried to obtain self-microporous negative photosensitive polyimide pellets.

[0070] Preferably, the alkali solution is ammonia water, sodium carbonate solution or sodium bicarbonate solution.

[0071] Preferably, the solvent used for redissolving is selected from one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, chloroform, dichloromethane or acetone. Preferably, the second solvent is one or a combination of at least two of methanol, ethanol, and pure water.

[0072] In the third aspect, the present invention provides a self-microporous negative photosensitive polyimide film, and the self-microporous negative photosensitive polyimide film is made of the self-microporous negative photosensitive polyimide material as described above.

[0073] In the fourth aspect, the present invention provides a preparation method of the self-microporous negative photosensitive polyimide film as described above, and the preparation method includes:

[0074] The solution of the self-microporous negative photosensitive polyimide material provided by the first aspect is cast or spin-coated on a substrate, and after drying the solvent, the self-microporous negative photosensitive polyimide film is obtained.

[0075] Preferably, the solid content of the solution of the self-microporous negative photosensitive polyimide material is 0.2-15 wt%, for example, it can be 0.2 wt%, 1 wt%, 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 15 wt%, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0076] Preferably, the solvent in the solution of the self-microporous negative photosensitive polyimide material is an organic solvent, and the organic solvent is selected from one or more of tetrahydrofuran, dioxane, chloroform, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol, phenol, p-chlorophenol, o-dichlorobenzene, 1,2,4-trichlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, ethyl acetate.

[0077] Preferably, the solvent is dried by gradient heating in sequence at room temperature (15-30 °C, such as 15 °C, 18 °C, 20 °C, 25 °C, 28 °C or 30 °C) for 2-48 h (such as 2 h, 5 h, 8 h, 10 h, 15 h, 18 h, 20 h, 24 h, 28 h, 30 h, 36 h, 40 h, 44 h or 48 h), at 60 °C for 1-5 h (such as 1 h, 2 h, 3 h, 4 h or 5 h), at 90 °C for 1-5 h (such as 1 h, 2 h, 3 h, 4 h or 5 h), at 120 °C for 1-5 h (such as 1 h, 2 h, 3 h, 4 h or 5 h), at 150 °C for 1-5 h (such as 1 h, 2 h, 3 h, 4 h or 5 h), and at 180 °C for 1-5 h (such as 1 h, 2 h, 3 h, 4 h or 5 h).

[0078] Preferably, the thickness of the self-microporous negative photosensitive polyimide film is 5-150 μm, for example, it can be 5 μm, 10 μm, 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 150 μm, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0079] In the fifth aspect, the present invention provides the application of the self-microporous negative photosensitive polyimide film as described above in photoresist and electronic packaging.

[0080] Compared with the prior art, the present invention has the following beneficial effects:

[0081] In the structure of the self - microporous negative photosensitive polyimide material provided by the present invention, by introducing benzophenone and methyl structures, cross - linking reaction can occur rapidly upon exposure without the need to add additional additives such as photoinitiators, resulting in solubility differences between the exposed area and the unexposed area, while enabling the polymer to maintain excellent thermal, mechanical, and electrical properties. In addition, the introduced Chaogel base in the structure has polar groups and a rigid twisted structure, which can increase the solubility of the polymer in polar solvents through the action of polar groups, steric hindrance effects, and inhibition of intermolecular forces, thereby increasing the solubility difference before and after exposure and improving the quality of the subsequent lithography pattern. The obtained photosensitive polyimide (PSPI) is fully imidized, so there is no need for subsequent high - temperature thermal imidization, avoiding a series of problems such as shrinkage of the polymer film caused by high - temperature post - baking dehydration curing after ultraviolet cross - linking of traditional photosensitive polyimides. The required exposure dose for the self - microporous negative photosensitive polyimide prepared to theoretically fully cross - link is 250 - 900 mJ / cm 2 , and it is expected to be applied in high - end fields such as photoresists for integrated circuits and OLED display panels. Specific embodiments

[0082] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0083] Example 1

[0084] This Example 1 provides a self - microporous negative photosensitive polyimide D1:

[0085]

[0086] Its synthesis reaction formula and specific method are as follows:

[0087]

[0088] At room temperature, 0.7992 g (3 mmol) of diamine monomer d2 was added to a dry three-necked flask. Under a nitrogen atmosphere, 11.2140 mL of N-methylpyrrolidone (NMP) was added to the reaction flask and stirred until dissolved. After complete dissolution, 0.3222 g (1 mmol) of dianhydride monomer d1 was added, and the solid content was 10%. Stirred in an ice-water bath for 12 h, 30 ml of water scavenger toluene was added and reacted at 180 °C for 9 h. After the reaction was completed, it was poured into deionized water to precipitate, filtered, washed several times with methanol, and placed in a vacuum drying oven and dried at 60 °C for 8 h to obtain a diamine monomer containing an imide ring. The obtained diamine monomer was reacted with DMM in trifluoroacetic acid at room temperature for 24 h, and then carefully alkalized with 2.5% ammonia water solution. The resulting solution was stirred to precipitate a white fibrous precipitate. The solid was filtered out and washed successively with water and methanol 3 times. The obtained fibrous precipitate was dissolved in chloroform, then precipitated in methanol, filtered, and after natural drying, it was further vacuum dried at 120 °C for 24 hours to obtain self-microporous negative photosensitive polyimide D1. Nuclear magnetic resonance test was carried out using a 600 MHz nuclear magnetic resonance spectrometer (Avance III 600 MHz spectrometer, Bruker, Switzerland). 1 HNMR(600MHz,DMSO-d6)δ8.34(d,J=2.0Hz,2H),8.20(dd,J=7.5,2.0Hz,2H),8.11(d,J=7.4Hz,2H),7.48–7.42(m,4H),7.20(dt,J=2.0,1.0Hz,1H),7.19–7.13(m,4H),7.06–7.02(m,1H),7.00(ddd,J=13.6,7.5,2.0Hz,2H),6.94–6.88(m,2H),4.24(s,1H),4.14(s,1H),3.67(d,J=1.1Hz,2H),2.12(dd,J=13.0,3.7Hz,4H),1.95(d,J=13.1Hz,3H),1.67(d,J=13.0Hz,3H),1.60(d,J=13.0Hz,4H),1.47(s,3H).

[0089] The obtained self-microporous negative photosensitive polyimide D1 was dissolved in N-methylpyrrolidone with a solid content of 5%. It was cast onto a substrate at 60 °C. After the casting solution was spread out, the temperature was gradually increased to 180 °C and kept warm for 2 h (the process of gradient temperature increase was to keep warm at room temperature for 2 h, increase the temperature to 60 °C and keep warm for 1 h, 90 °C and keep warm for 1 h, 120 °C and keep warm for 1 h, 150 °C and keep warm for 1 h, and then increase the temperature to 180 °C). After cooling to room temperature, the film was peeled off to obtain a polyimide film containing benzophenone, methyl, and chaogor base structures.

[0090] The obtained microporous negative photosensitive polyimide D1 film was made into a size of 0.5 cm × 4 cm, and its tensile properties were tested by a dynamic mechanical analyzer Q800 (TA Instruments, USA). The results showed that the tensile strength was above 75 MPa and the elongation at break was above 6%, indicating excellent mechanical properties.

[0091] The obtained microporous negative photosensitive polyimide D1 was subjected to TGA testing to measure its thermal decomposition temperature T d , and the instrument model was TG-DTA6300 (NSK LTD, Tokyo, Japan). The results showed that its T d5％ was above 400 °C. The obtained microporous negative photosensitive polyimide D1 was subjected to DMA testing to measure its glass transition temperature T g , and the instrument model was DMA Q800 (TA Instruments, USA). The results showed that T g was above 400 °C.

[0092] In-situ infrared testing of the obtained microporous negative photosensitive polyimide D1 film under ultraviolet light irradiation was carried out. At the accuracy of obtaining an infrared image in 0.7 s, it was measured that D1 completed most of the ultraviolet cross-linking observable from valence bonds in 2.80 s, and the required exposure dose was 300 - 600 mJ / cm 2 .

[0093] Example 2

[0094] This Example 2 provides a self-microporous negative photosensitive polyimide D2:

[0095]

[0096] Its synthesis reaction formula and specific method are as follows:

[0097]

[0098] At room temperature, 1.0335 g (3 mmol) of diamine monomer d3 was added to a dry three-necked flask. Under a nitrogen atmosphere, 13.5570 mL of N-methylpyrrolidone (NMP) was added to the reaction flask and stirred until dissolved. After complete dissolution, 0.3222 g (1 mmol) of dianhydride monomer d1 was added, and the solid content was 10%. Stirring was carried out in an ice-water bath for 12 h. Then, 30 ml of water-removing agent toluene was added, and the reaction was carried out at 180 °C for 9 h. After the reaction was completed, the product was poured into deionized water for precipitation, filtered, washed several times with methanol, and dried in a vacuum drying oven at room temperature for 8 h at 60 °C to obtain a diamine monomer containing an imide ring. The obtained diamine monomer was reacted with DMM in trifluoroacetic acid at room temperature for 24 h, and then carefully alkalized with 2.5% aqueous ammonia solution. The resulting solution was stirred to precipitate a white fibrous precipitate. The solid was filtered out and washed 3 times successively with water and methanol. The obtained fibrous precipitate was dissolved in chloroform and then precipitated in methanol, filtered, and naturally dried. Then, it was further dried in vacuo at 120 °C for 24 h to obtain self-microporous negative photosensitive polyimide D2. NMR test was carried out using a 600 MHz nuclear magnetic resonance spectrometer (Avance III 600 MHz spectrometer, Bruker, Switzerland). 1H NMR (600 MHz, DMSO-d6) δ 8.34 (d, J = 2.0 Hz, 1H), 8.20 (dd, J = 7.5, 2.0 Hz, 1H), 8.11 (d, J = 7.4 Hz, 1H), 7.40–7.35 (m, 2H), 7.31–7.24 (m, 2H), 7.23–7.15 (m, 4H), 7.09 (ddt, J = 11.3, 2.1, 1.0 Hz, 1H), 7.04–6.96 (m, 1H), 6.79 (d, J = 7.5 Hz, 0H), 3.67 (d, J = 1.1 Hz, 1H), 1.70 (s, 6H), 1.67 (d, J = 3.1 Hz, 6H).

[0099] The obtained self-microporous negative photosensitive polyimide D2 was dissolved in N-methylpyrrolidone with a solid content of 5%. It was cast onto a substrate at 60 °C. After the casting solution had spread out, the temperature was gradually increased to 180 °C and held for 2 h (the temperature gradient program was the same as in Example 1). After cooling to room temperature, the film was peeled off to obtain a polyimide film containing benzophenone, methyl, and chaogor base structures.

[0100] The obtained self-microporous negative photosensitive polyimide D2 film was made into a size of 0.5 cm × 4 cm, and its tensile properties were tested by a dynamic mechanical analyzer Q800 (TA Instruments, USA). The results showed that the tensile strength was above 85 MPa and the elongation at break was above 10%, indicating excellent mechanical properties;

[0101] TGA test was carried out on the obtained self-microporous negative photosensitive polyimide D2 to measure its thermal decomposition temperature Td The instrument model is TG-DTA6300 (NSK LTD, Tokyo, Japan), and the results show that its T d5％ is above 450 °C; The DMA test was carried out on the obtained microporous negative photosensitive polyimide D2 to measure its glass transition temperature T g The instrument model is DMA Q800 (TA Instruments, USA), and the results show that T g is above 400 °C;

[0102] In-situ infrared testing was carried out on the obtained microporous negative photosensitive polyimide D2 film under ultraviolet light irradiation. With an accuracy of obtaining an infrared image in 0.7 s, it was measured that D2 completed most of the ultraviolet cross-linking observable from the valence bond in 2.10 s, and the required exposure dose was 250 - 550 mJ / cm 2 .

[0103] Example 3

[0104] This Example 3 provides a self-microporous negative photosensitive polyimide D3:

[0105]

[0106] Its synthesis reaction formula and specific method are as follows:

[0107]

[0108] At room temperature, 0.7211 g (3 mmol) of diamine monomer d4 was added to a dry three-necked flask. Under a nitrogen atmosphere, 10.4325 mL of N-methylpyrrolidone (NMP) was added to the reaction flask and stirred to dissolve. After complete dissolution, 0.3222 g (1 mmol) of dianhydride monomer d1 was added, with a solid content of 10%. Stirring was carried out in an ice-water bath for 12 h, 30 ml of water-removing agent toluene was added, and the reaction was carried out at 180 °C for 9 h. After the reaction was completed, it was poured into deionized water to precipitate, filtered, washed several times with methanol, and placed in a vacuum drying oven and dried at room temperature for 8 h at 60 °C to obtain a diamine monomer containing an imide ring. The obtained diamine monomer was reacted with DMM in trifluoroacetic acid at room temperature for 24 h, and then carefully alkalized with 2.5% ammonia water solution. The obtained solution was stirred to precipitate a white fibrous precipitate. The solid was filtered out and washed 3 times successively with water and methanol. The obtained fibrous precipitate was dissolved in chloroform, then precipitated in methanol, filtered, and after natural drying, it was further vacuum dried at 120 °C for 24 hours to obtain self-microporous negative photosensitive polyimide D3. NMR testing was carried out using a 600 MHz nuclear magnetic resonance spectrometer (Avance III 600 MHz spectrometer, Bruker, Switzerland), 1HNMR (600 MHz, DMSO-d6) δ 8.34 (d, J = 2.0 Hz, 2H), 8.20 (dd, J = 7.5, 2.0 Hz, 2H), 8.11 (d, J = 7.4 Hz, 2H), 7.30 (d, J = 7.5 Hz, 1H), 7.15–7.10 (m, 3H), 7.08 (dq, J = 2.1, 1.1 Hz, 2H), 6.97 (dq, J = 2.0, 1.1 Hz, 1H), 6.86 (h, J = 0.7 Hz, 2H), 4.19 (s, 1H), 3.66 (d, J = 0.9 Hz, 1H), 3.57 (d, J = 0.9 Hz, 1H), 2.95–2.91 (m, 5H), 2.88 (t, J = 1.0 Hz, 2H), 2.26–2.23 (m, 12H).

[0109] The obtained self-microporous negative photosensitive polyimide D3 was dissolved in N-methylpyrrolidone with a solid content of 10%, cast onto a substrate at 60 °C. After the casting solution spread out, the temperature was gradually increased to 180 °C and kept for 2 h (the temperature gradient program was the same as that in Example 1). After cooling to room temperature, the film was peeled off to obtain a polyimide film containing benzophenone, methyl, and chaogor base structures.

[0110] The obtained self-microporous negative photosensitive polyimide D3 film was made into a size of 0.5 cm × 4 cm, and its tensile properties were tested by a dynamic mechanical analyzer Q800 (TA Instruments, USA). The results showed that the tensile strength was above 125 MPa and the elongation at break was above 9.5%, indicating excellent mechanical properties;

[0111] The obtained self-microporous negative photosensitive polyimide D3 was subjected to TGA testing to measure its thermal decomposition temperature T d , and the instrument model was TG-DTA6300 (NSK LTD, Tokyo, Japan). The results showed that its T d5％ was above 448 °C; the obtained self-microporous negative photosensitive polyimide D3 was subjected to DMA testing to measure its glass transition temperature T g , and the instrument model was DMA Q800 (TA Instruments, USA). The results showed that T g was above 400 °C;

[0112] The obtained self-microporous negative photosensitive polyimide D3 film was subjected to in-situ infrared testing under ultraviolet light. With an accuracy of obtaining an infrared image at 0.7 s, it was measured that D3 completed most of the ultraviolet cross-linking observable from the valence bond in 3.03 s, and the required exposure dose was 300 - 600 mJ / cm 2 .

[0113] Example 4

[0114] Example 4 provides a self-microporous negative photosensitive polyimide D4:

[0115]

[0116] Its synthesis reaction formula and specific method are as follows:

[0117]

[0118] At room temperature, add 0.6368 g (3 mmol) of diamine monomer d6 to a dry three-necked flask. Under a nitrogen atmosphere, add 11.5724 mL of N-methylpyrrolidone (NMP) to the reaction flask and stir to dissolve. After complete dissolution, add 0.5205 g (1 mmol) of dianhydride monomer d5. The solid content is 10%. Stir in an ice-water bath for 12 h, add 30 ml of water-removing agent toluene and react at 180 °C for 9 h. After the reaction is completed, pour it into deionized water to precipitate, filter, wash several times with methanol, and place it in a vacuum drying oven to dry at room temperature for 8 h at 60 °C to obtain a diamine monomer containing an imide ring. React the obtained diamine monomer with DMM in trifluoroacetic acid at room temperature for 24 h, and then carefully basify with 2.5% aqueous ammonia solution. Stir the obtained solution to precipitate a yellow fibrous precipitate. Filter out the solid and wash it 3 times successively with water and methanol. Dissolve the obtained fibrous precipitate in chloroform, then precipitate it in methanol, filter, and after natural drying, continue to dry it in vacuo at 120 °C for 24 hours to obtain self-microporous negative photosensitive polyimide D4. Use a 600 MHz nuclear magnetic resonance spectrometer (Avance III 600 MHz spectrometer, Bruker, Switzerland) for nuclear magnetic resonance testing, 1 HNMR(600MHz,DMSO-d6)δ8.06(d,J=7.5Hz,1H),7.94–7.89(m,2H),7.72–7.66(m,3H),7.68–7.62(m,2H),7.58(dq,J=2.0,1.0Hz,1H),7.40(dd,J=7.5,2.0Hz,1H),7.27–7.21(m,3H),7.02–6.97(m,2H),3.66(d,J=1.1Hz,1H),1.67(s,2H).

[0119] Dissolve the obtained self-microporous negative photosensitive polyimide D4 in N-methylpyrrolidone with a solid content of 10%. Cast it onto a substrate at 60 °C. After the casting solution spreads out, gradually raise the temperature to 180 °C and keep it warm for 2 h (the temperature gradient program is the same as in Example 1). After cooling to room temperature, peel off the film to obtain a polyimide film containing benzophenone, methyl, and Choeger base structures.

[0120] The obtained microporous negative photosensitive polyimide D4 film was made into a size of 0.5 cm × 4 cm, and its tensile properties were tested by a dynamic mechanical analyzer Q800 (TA Instruments, USA). The results showed that the tensile strength was above 120 MPa, the elongation at break was above 9.8%, and the mechanical properties were excellent;

[0121] The obtained microporous negative photosensitive polyimide D4 was subjected to TGA testing to measure its thermal decomposition temperature T d , and the instrument model was TG-DTA6300 (NSK LTD, Tokyo, Japan). The results showed that its T d5％ was above 468 °C; the obtained microporous negative photosensitive polyimide D4 was subjected to DMA testing to measure its glass transition temperature T g , and the instrument model was DMA Q800 (TA Instruments, USA). The results showed that T g was above 400 °C;

[0122] In-situ infrared testing of the obtained microporous negative photosensitive polyimide D4 film under ultraviolet light irradiation was carried out. At the accuracy of obtaining an infrared image in 0.7 s, it was measured that D4 completed most of the ultraviolet cross-linking that could be observed from the valence bond in 2.27 s, and the required exposure amount was 280 - 580 mJ / cm 2 .

[0123] Example 5

[0124] This Example 5 provides a microporous negative photosensitive polyimide D5:

[0125]

[0126] Its synthesis reaction formula and specific method are as follows:

[0127]

[0128] At room temperature, 0.6368 g (3 mmol) of diamine monomer d6 was placed into a dry three-necked flask. Under a nitrogen atmosphere, 8.8895 mL of N-methylpyrrolidone (NMP) was added to the reaction flask and stirred until dissolved. After complete dissolution, 0.2522 g (1 mmol) of dianhydride monomer d7 was added, with a solid content of 10%. Stirring was carried out in an ice-water bath for 12 h. 30 ml of water-removing agent toluene was added and the reaction was carried out at 180 °C for 9 h. After the reaction was completed, it was poured into deionized water for precipitation, filtration, washed several times with methanol, and placed in a vacuum drying oven for drying at room temperature for 8 h at 60 °C to obtain a diamine monomer containing an imide ring. The obtained diamine monomer was reacted with DMM in trifluoroacetic acid at room temperature for 24 h, and then carefully alkalized with 2.5% aqueous ammonia solution. The resulting solution was stirred to precipitate a white fibrous precipitate. The solid was filtered out and washed successively with water and methanol 3 times. The obtained fibrous precipitate was dissolved in chloroform and then precipitated in methanol, filtered, and naturally dried, and then further dried under vacuum at 120 °C for 24 hours to obtain self-microporous negative photosensitive polyimide D5. NMR tests were carried out using a 600 MHz nuclear magnetic spectrometer (Avance III 600 MHz spectrometer, Bruker, Switzerland), 1 HNMR(600MHz,DMSO-d6)δ7.94–7.89(m,4H),7.70(dt,J=2.1,1.0Hz,1H),7.65(ddd,J=13.0,7.5,2.0Hz,2H),7.58(dq,J=1.9,0.9Hz,1H),7.51–7.46(m,4H),7.25(dq,J=7.5,0.9Hz,1H),7.05(d,J=7.5Hz,1H),4.24(s,1H),4.14(s,1H),3.69(d,J=1.1Hz,1H),3.64(d,J=0.9Hz,1H),3.51–3.45(m,1H),1.46(s,6H).

[0129] The obtained self-microporous negative photosensitive polyimide D5 was dissolved in N-methylpyrrolidone with a solid content of 10%. It was cast onto a substrate at 60 °C. After the casting solution had spread out, the temperature was gradually raised to 180 °C and held for 2 h (the temperature gradient program was the same as in Example 1). After cooling to room temperature, the film was peeled off to obtain a polyimide film containing benzophenone, methyl, and chaogor base structures.

[0130] The obtained self-microporous negative photosensitive polyimide D5 film was made into a size of 0.5 cm × 4 cm, and its tensile properties were tested by a dynamic mechanical analyzer Q800 (TA Instruments, USA). The results showed that the tensile strength was above 130 MPa and the elongation at break was above 8.0%, with excellent mechanical properties;

[0131] The obtained microporous negative photosensitive polyimide D5 was subjected to TGA testing to measure its thermal decomposition temperature T d , and the instrument model was TG-DTA6300 (NSK LTD, Tokyo, Japan). The results showed that its T d5％ was above 468 °C; the obtained microporous negative photosensitive polyimide D5 was subjected to DMA testing to measure its glass transition temperature T g , and the instrument model was DMA Q800 (TA Instruments, USA). The results showed that T g was above 400 °C;

[0132] The obtained microporous negative photosensitive polyimide D5 film was subjected to in-situ infrared testing under ultraviolet light irradiation. With an accuracy of obtaining an infrared image in 0.7 s, it was measured that D5 completed most of the ultraviolet cross-linking observable from the valence bonds in 3.79 s, and the required exposure dose was 550–900 mJ / cm 2 .

[0133] Comparative Example

[0134] This comparative example provides a negative photosensitive polyimide E without introducing the Chaogel base structure:

[0135]

[0136] Its synthesis reaction formula and specific method are as follows:

[0137]

[0138] At room temperature, 0.6368 g (3 mmol) of diamine monomer d6 was placed into a dry three-necked flask. Under a nitrogen atmosphere, 5.5736 mL of N-methylpyrrolidone (NMP) was added to the reaction flask and stirred to dissolve. After complete dissolution, 0.7567 (3 mmol) of dianhydride monomer d7 was added, with a solid content of 25%. Stirring was carried out in an ice-water bath for 12 h, and NMP was added to reduce the solid content to 15%. 30 ml of water-removing agent toluene was added and reacted at 180 °C for 9 h. After the reaction ended, it was poured into deionized water to precipitate, filtered, washed several times with methanol, and placed in a vacuum drying oven and dried at 60 °C for 8 h to obtain negative photosensitive polyimide E. NMR testing was carried out using a 600 MHz nuclear magnetic spectrometer (Avance III 600 MHz spectrometer, Bruker, Switzerland). 1H NMR (600 MHz, DMSO-d6) δ 7.94–7.89 (m, 1H), 7.78–7.73 (m, 1H), 7.51–7.46 (m, 1H), 7.31 (dq, J = 7.7, 1.1 Hz, 1H), 1.44 (d, J = 3.1 Hz, 6H).

[0139] The obtained negative photosensitive polyimide E was dissolved in N-methylpyrrolidone with a solid content of 10%. It was cast onto a substrate at 60 °C. After the casting solution spread out completely, the temperature was gradually increased to 180 °C and kept for 2 h (the temperature gradient program was the same as that in Example 1). After cooling to room temperature, the film was peeled off to obtain a polyimide film containing benzophenone and methyl but without the Chaogel base structure.

[0140] The obtained negative photosensitive polyimide E film was made into a size of 0.5 cm × 4 cm, and its tensile properties were tested by a dynamic mechanical analyzer Q800 (TA Instruments, USA). The results showed that the tensile strength was above 60 MPa and the elongation at break was above 5.0%.

[0141] The obtained negative photosensitive polyimide E was subjected to TGA test to measure its thermal decomposition temperature T d , and the instrument model was TG-DTA6300 (NSK LTD, Tokyo, Japan). The results showed that its T d5％ was above 430 °C; the obtained negative photosensitive polyimide E was subjected to DMA test to measure its glass transition temperature T g , and the instrument model was DMAQ800 (TA Instruments, USA). The results showed that T g was above 350 °C;

[0142] The obtained negative photosensitive polyimide E film was subjected to in-situ infrared test under ultraviolet light. With an accuracy of obtaining an infrared image in 0.7 s, it was measured that E completed most of the ultraviolet cross-linking that could be observed from the valence bonds in 5.82 s, and the required exposure dose was 1200 - 1600 mJ / cm 2 .

[0143] The applicant declares that the present invention uses the above embodiments to illustrate the self-microporous negative photosensitive polyimide material and its preparation method and application of the present invention, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the products of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A self - contained microporous negative photosensitive polyimide material, characterized in that, The self-microporous negative photosensitive polyimide has the structure shown in Formula I: Wherein, Ar1 is an aromatic or alicyclic dianhydride residue containing a carbonyl group or an alkyl group, and Ar2 is an aromatic diamine residue containing a carbonyl group or an alkyl group; and Ar1 and Ar2 are not simultaneously a structure containing a carbonyl group; n is an integer from 100 to 10,000.

2. The self-microporous negative photosensitive polyimide material according to claim 1, wherein When Ar1 contains a carbonyl group, Ar2 is an aromatic diamine residue containing an alkyl group; when Ar2 contains a carbonyl group, Ar1 is an aromatic or alicyclic dianhydride residue containing an alkyl group; Preferably, when Ar1 is a structure containing a carbonyl group, Ar2 has the following unsubstituted or substituted structure: Wherein, X is a straight-chain or branched-chain alkyl group with 1 to 16 carbon atoms or a cycloalkyl group with 3 to 16 carbon atoms; Y1 to Y 15 are each independently selected from the group consisting of H, a linear or branched alkyl group having 1 to 16 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, an amino group, a dimethylamino group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonyl group, a mercapto group, a methoxy group, an aldehyde group, and a halogen atom; The dotted line represents the connection site of the group; Preferably, when Ar1 is a structure containing a carbonyl group, the structure containing a carbonyl group includes: The dotted line represents the connection site of the group.

3. The self-microporous negative photosensitive polyimide material according to claim 1 or 2, characterized in that, When Ar2 is a structure containing a carbonyl group, Ar1 has an alkyl-substituted structure; Preferably, when Ar2 is a structure containing a carbonyl group, Ar1 includes the following structure: Wherein m is an integer from 2 to 5, and the dotted line represents the connection site of the group; Preferably, when Ar2 is a structure containing a carbonyl group, the structure containing a carbonyl group includes: The dotted line represents the connection site of the group.

4. The self-microporous negative photosensitive polyimide material according to any one of claims 1 to 3, characterized in that The weight-average molecular weight of the self-microporous negative photosensitive polyimide is 50,000 to 1,000,000.

5. The preparation method of the self-microporous negative photosensitive polyimide material according to any one of claims 1 to 4, characterized in that, The preparation method includes: (1) Reacting an aromatic or alicyclic dianhydride A with an aromatic diamine B to obtain a diamino monomer containing an amide group. (2) Reacting the diamino monomer containing an amide group with a formaldehyde source to obtain the self-microporous negative photosensitive polyimide; The diamine monomer containing an amide group has the structure shown in Formula II: Wherein R1 is an aromatic or alicyclic dianhydride residue; R2 is an aromatic diamine residue; The self-microporous negative photosensitive polyimide has the structure shown in Formula I; 6. The preparation method according to claim 5, characterized in that When the aromatic or alicyclic dianhydride A contains a carbonyl group, the aromatic diamine B has the following structure: X is a straight-chain or branched-chain alkyl group with 1 to 16 carbon atoms or a cycloalkyl group with 3 to 16 carbon atoms; Z1 to Z 15 are each independently selected from the group consisting of H, a linear or branched alkyl group having 1 to 16 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, an amino group, a dimethylamino group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonyl group, a mercapto group, a methoxy group, an aldehyde group, and a halogen atom; Preferably, when A is a structure containing a carbonyl group, the structure containing a carbonyl group includes: Preferably, when the aromatic diamine B contains a carbonyl group, the aromatic or alicyclic dianhydride A has the following structure: Preferably, when B is a structure containing a carbonyl group, the structure containing a carbonyl group includes: Preferably, the molar ratio of the aromatic or alicyclic dianhydride A to the aromatic diamine B in step (1) is (1 to 1.05):3; Preferably, the reaction in step (1) is carried out in the presence of a solvent; Preferably, the solvent includes a high-boiling solvent; Preferably, the high-boiling polar solvent includes any one or at least two combinations of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol, or dimethyl sulfoxide; Preferably, the temperature of the reaction in step (1) is 0 to 10 °C; Preferably, the reaction time in step (1) is 6 to 24 h; Preferably, after the reaction in step (1) is completed, an azeotropic agent is added for a secondary reaction and purification to obtain the diamine monomer containing an amide group; Preferably, the azeotropic agent includes any one or a combination of at least two of toluene, xylene or chlorobenzene; Preferably, the temperature of the secondary reaction is 150-200 °C; Preferably, the time of the secondary reaction is 2-80 h; Preferably, the purification includes evaporating the azeotropic agent, pouring the reaction solution into a mixed solution of methanol and water to precipitate a solid product, then redissolving it, pouring it into ethanol to precipitate, filtering, and drying to obtain a diamine monomer containing an amide group; Preferably, the solvent used for redissolving is selected from one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, chloroform, dichloromethane or acetone; Preferably, the formaldehyde source agent in step (2) includes any one or a combination of at least two of formaldehyde, paraformaldehyde, hexamethylenetetramine, dimethoxymethane or ethylene glycol dimethyl ether; Preferably, the reaction in step (2) is carried out in an acidic solvent; Preferably, the pH value of the acidic solvent is 0.5-6; Preferably, the acidic solvent includes any one or a combination of at least two of trifluoroacetic acid, polyphosphoric acid, formic acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid or hydrochloric acid; Preferably, after mixing the diamine monomer containing an amide group with the formaldehyde source agent, a solvent is added for reaction; Preferably, the molar ratio of the diamine monomer containing an amide group to the formaldehyde source agent in step (2) is 4-10:1; Preferably, the mixing temperature is -5-30 °C; Preferably, the reaction time in step (2) is 24-240 h; Preferably, after the reaction in step (2) is completed, an alkali solution is added to the reaction solution to precipitate a fibrous or powdery solid product. The obtained fibrous or powdery solid product is redissolved, poured into a second solvent to precipitate, washed, and dried to obtain self-microporous negative photosensitive polyimide pellets; Preferably, the alkali solution is ammonia water, sodium carbonate solution or sodium bicarbonate solution; Preferably, the solvent used for redissolving is selected from one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, chloroform, dichloromethane or acetone; Preferably, the second solvent is one or a combination of at least two of methanol, ethanol or pure water.

7. A self-porous negative photosensitive polyimide film, characterized in that, The self-microporous negative photosensitive polyimide film is made of the self-microporous negative photosensitive polyimide material according to any one of claims 1-4.

8. A method for preparing a self-microporous negative photosensitive polyimide film as described in claim 7, characterized in that, The preparation method includes: Flowing or spin-coating a solution of the self-microporous negative photosensitive polyimide material according to any one of claims 1-4 on a substrate, and drying the solvent to obtain the self-microporous negative photosensitive polyimide film.

9. The preparation method according to claim 8, characterized in that, The solid content of the solution of the self-microporous negative photosensitive polyimide material is 0.2-15 wt%; Preferably, the solvent in the solution of the self-microporous negative photosensitive polyimide material is an organic solvent, and the organic solvent is selected from one or a combination of at least two of tetrahydrofuran, dioxane, chloroform, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, m-cresol, phenol, p-chlorophenol, o-dichlorobenzene, 1,2,4-trichlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, ethyl acetate; Preferably, the solvent is dried by gradient heating in sequence at room temperature for 2 to 48 hours, at 60 °C for 1 to 5 hours, at 90 °C for 1 to 5 hours, at 120 °C for 1 to 5 hours, at 150 °C for 1 to 5 hours, and at 180 °C for 1 to 5 hours; Preferably, the thickness of the self-microporous negative photosensitive polyimide film is 5 to 150 μm.

10. The application of the self-microporous negative photosensitive polyimide film according to claim 7 in a photoresist and electronic packaging.

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