Negative photosensitive polyimide resin, preparation method thereof, photoresist composition and application

Abstract

The invention provides negative photosensitive polyimide resin, a preparation method thereof, a photoresist composition containing the negative photosensitive polyimide resin and application of the photoresist composition. The negative photosensitive polyimide resin is obtained by sequentially carrying out polymerization reaction on a dianhydride monomer and a diamine monomer, carrying out dehydration imidization reaction through a dehydrating agent and a catalyst in the presence of a solvent, and finally adding photosensitive tertiary amine for reaction. The photoresist composition comprises the negative photosensitive polyimide resin, a cross-linking agent, a photosensitizer, a photoinitiator and a solvent. The photoresist composition disclosed by the invention has the characteristics of low-temperature curing and good copper adhesive force, and can be widely applied to the field of advanced packaging of semiconductors.

Description

Technical Field

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

[0002] In the process of forming the internal structure of semiconductor devices, photolithography technology is needed. Photolithography can use exposure and development to depict geometric structures on the photoresist layer, and then form various circuit structures. Photoresists can be divided into positive photoresists and negative photoresists according to the pattern type.

[0003] Among advanced packaging technologies, a fan-out wafer packaging technology has attracted widespread attention. This technology can extend the chip I / O structure outside the chip, thereby greatly expanding the design freedom and integrating multiple chips with different functions into one package to achieve system-level packaging. Among them, the redistribution layer is the core structure of the fan-out wafer packaging.

[0004] Polyimide (PI) is a polymer material with good dielectric properties, high mechanical strength and strong heat resistance, and is widely used in electrical, aerospace and automotive industries. Especially in the semiconductor field, PI, as an important insulating material, is widely used as stress buffer layer, dielectric insulation layer, surface passivation layer of integrated circuits, and surface planarization layer and protective layer of redistribution layer in wafer-level packaging.

[0005] In the formation process of the redistribution layer, a photosensitive polyimide photoresist material is required to be used as a Cu / Ti alloy sputtering substrate and patterning tool, and then remain in the packaging structure as a stress buffer layer and a dielectric insulation layer.

[0006] The curing temperature of traditional photosensitive polyimide is generally high, all above 300°C, but this cannot meet the requirements of current advanced semiconductor packaging processes. At such temperatures, the wafer may warp, the low-melting-point solder balls may crack, fall off or recrystallize, and high-temperature curing will produce very large residual stress, which may damage the underlying stacked structure, affect the dielectric properties, and cause device function degradation or even damage.

[0007] Therefore, in order to meet the requirements of the current advanced semiconductor packaging process, it is necessary to research and develop a negative photosensitive polyimide photoresist with low-temperature curing function. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a negative photosensitive polyimide resin capable of imparting low-temperature curing properties to a photoresist composition, a preparation method thereof, a photoresist composition and applications thereof.

[0009] Specifically, one aspect of the present invention provides a negative photosensitive polyimide resin having low temperature curing properties, wherein the negative photosensitive polyimide resin has a structure shown in Formula I:

[0010]

[0011] Wherein, Ar1 is a tetravalent group containing two benzene rings;

[0012] Ar2 is a divalent group containing two or more benzene rings and one or more ether bonds;

[0013] x=(S 1659 / S 1500 ) T / (S 1659 / S 1500 ) T’ , x is 0.78~0.91;

[0014] Among them (S 1659 / S 1500 ) T The infrared spectrum of negative photosensitive polyimide resin is at 1659cm -1 The characteristic peak area at 1500cm -1 The ratio of the characteristic peak areas at 1659 / S 1500 ) T’ The infrared spectrum of the polymer after being treated with a dehydrating agent and a catalyst is at 1659 cm -1 The characteristic peak area at 1500cm -1 The ratio of the characteristic peak areas at

[0015] n=Mw / Mr, n is 300~1300;

[0016] Wherein Mw is the weight average molecular weight of the polymer obtained by gel permeation chromatography, and Mr is the relative molecular mass of the repeating unit of the polymer.

[0017] In one or more embodiments, Ar1 is selected from one or more of the following groups:

[0018]

[0019] In one or more embodiments, Ar2 is selected from one or more of the following groups:

[0020]

[0021] In one or more embodiments, Ar1 is selected from one or more of the following groups:

[0022]

[0023]

[0024] Furthermore, Ar2 is selected from one or more of the following groups:

[0025]

[0026] Another aspect of the present invention provides a method for preparing a negative photosensitive polyimide resin, which comprises the following steps:

[0027] (1) dissolving a diamine monomer in an organic solvent, adding a dianhydride monomer, and performing a polymerization reaction at -5°C to 10°C for 8 to 14 hours to obtain a polyamic acid liquid;

[0028] (2) washing and drying the polyamic acid liquid to obtain a polyamic acid solid; dissolving the polyamic acid solid in an organic solvent to obtain an intermediate, wherein the mass of the polyamic acid in the intermediate is 10 wt% to 50 wt% of the total mass of the intermediate;

[0029] (3) adding a dehydrating agent and a catalyst to the intermediate, stirring at room temperature for 4 to 10 hours to carry out a dehydration imidization reaction to obtain a negative photosensitive polyimide resin X;

[0030] (4) adding a photosensitive tertiary amine to the negative photosensitive polyimide resin and stirring at room temperature for 6 to 12 hours to obtain a negative photosensitive polyimide resin Y;

[0031] Wherein, the structure of the dianhydride monomer is The structure of the diamine monomer is H2N-Ar2-NH2;

[0032] The unit structure of the negative photosensitive polyimide resin X is shown in formula (II);

[0033]

[0034] The unit structure of the negative photosensitive polyimide resin Y is shown in formula (I), wherein the proportion of the unit structure shown in formula (II) in Y is x, and the proportion of the unit structure shown in formula (III) in Y is (1-x);

[0035]

[0036] In one or more embodiments, the method for preparing a negative photosensitive polyimide resin is characterized in that:

[0037] In step (1), the molar ratio of the dianhydride monomer to the diamine monomer is (1.01-1.1):1;

[0038] In steps (1) and (2), the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, N-methylpyrrolidone, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether, propylene glycol monomethyl ether, and isopropanol;

[0039] In step (3), the dehydrating agent is selected from one or more of acetic anhydride, maleic anhydride, trifluoroacetic anhydride and N,N'-dicyclohexylcarbodiimide; the catalyst is selected from one or more of triethylamine, pyridine, diethylethanolamine, quinoline and isoquinoline; and the reaction temperature is 0 to 30°C.

[0040] In one or more embodiments, the method for preparing a negative photosensitive polyimide resin is characterized in that, in step (4), the mass ratio of the photosensitive tertiary amine to the polyamic acid solid in the intermediate is 1: (1 to 2.5); the reaction temperature is 0°C to 30°C; and the photosensitive tertiary amine is selected from one or more of N-methyldiethanolamine, N-ethyldiethanolamine, N-methyl-4-aminobenzoate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate.

[0041] Another aspect of the present invention provides a negative photosensitive polyimide resin prepared by the method for preparing a negative photosensitive polyimide resin described in any embodiment of the present invention.

[0042] The invention provides a negative photosensitive polyimide photoresist composition, wherein the negative photosensitive polyimide resin is grafted with photosensitive tertiary amine dimethylaminoethyl methacrylate onto polyamic acid containing ether bonds of a specific structure through ionic bonding during the synthesis process, and the negative photosensitive polyimide photoresist has the characteristic of low-temperature curing through chemical imidization; wherein the ether bond structure contained in the main chain of the negative photosensitive polyimide makes the negative photosensitive polyimide photoresist have good adhesion to copper.

[0043] The invention provides a negative photosensitive polyimide photoresist composition, which comprises a cross-linking agent with a specific structure and can ensure the clarity and integrity of the pattern after curing.

[0044] Another aspect of the present invention provides a negative photosensitive polyimide photoresist composition, the negative photosensitive polyimide photoresist composition comprises the negative photosensitive polyimide resin described in any embodiment of the present invention, and further comprises an organic solvent, a crosslinking agent, a photosensitizer and a photoinitiator;

[0045] Based on the total mass of the negative photosensitive polyimide photoresist composition, in the photoresist composition, the content of the negative photosensitive polyimide resin Y is 10wt%-50wt%, the content of the organic solvent is 40wt%-85wt%, the content of the crosslinker is 0.1wt%-5wt%, the content of the photosensitizer is 1wt%-10wt%, and the content of the photoinitiator is 1wt%-10wt%.

[0046] In one or more embodiments, the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, N-methylpyrrolidone, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether, propylene glycol monomethyl ether, and isopropanol.

[0047] In one or more embodiments, the crosslinking agent is a compound having a methacrylic acid structure or an acrylic acid structure, and is selected from one or more of glycidyl methacrylate, trivinyl methacrylate, polyethylene glycol dimethacrylate, ethylene glycol diacrylate and hexafluoroacrylate.

[0048] In one or more embodiments, the photosensitizer is a compound having a benzophenone structure, selected from one or more of benzophenone, 4,4'-diaminobenzophenone and (dimethylamino)benzophenone compounds.

[0049] In one or more embodiments, the photoinitiator is a compound containing a benzophenone structure / imidazole structure / oxime ester structure, selected from one or more of 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), and the like.

[0050] The present invention also provides use of the negative photosensitive polyimide photoresist composition described in any embodiment of the present invention in semiconductor packaging.

[0051] The present invention grafts photosensitive tertiary amine dimethylaminoethyl methacrylate onto polyamic acid containing ether bonds of a specific structure through ionic bonding, and obtains a negative photosensitive polyimide resin capable of achieving low-temperature curing through chemical imidization. The ether bond structure contained in the main chain of the negative photosensitive polyimide of the present invention can achieve good adhesion to copper, and the cross-linking agent of the specific structure can ensure the clarity and integrity of the pattern after curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the infrared spectrum of negative photosensitive polyimide photoresist resin.

[0053] Figure 2 This is the infrared spectrum of the photoresist film after the negative photosensitive polyimide photoresist is cured. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in this document. Unless otherwise specified, all technical and scientific terms used in this document have the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definitions in this specification shall prevail.

[0055] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0056] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0057] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0058] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0059] Herein, the sum of the percentages of the various components of the composition is 100%.

[0060] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope defined by the present invention.

[0061] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0062] Herein, hexafluorodianhydride is the abbreviation of 4,4′-(hexafluoroisopropylene) diphthalic anhydride.

[0063] Negative photosensitive polyimide resin

[0064] The negative photosensitive polyimide resin of the present invention may have a structure shown in Formula I:

[0065]

[0066] Wherein, Ar1 is a tetravalent group containing two benzene rings;

[0067] Ar2 is a divalent group containing two or more benzene rings and one or more ether bonds;

[0068] x is the quantitative ratio between the two structural units, x = (S 1659 / S 1500 ) T / (S 1659 / S 1500 ) T’ , x is 0.7~1. 1659 / S 1500 ) T The infrared spectrum of the polymer is at 1659cm -1 The characteristic peak area at 1500cm -1 The ratio of the characteristic peak areas at 1659 / S 1500 ) T’ The infrared spectrum of the polymer after being treated with a dehydrating agent and a catalyst is at 1659 cm -1 The characteristic peak area at 1500cm -1 The ratio of the characteristic peak areas at

[0069] In one or more embodiments, x is from 0.7 to 1; preferably, x is from 0.78 to 0.91; more preferably, x is 0.70, 0.75, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.95 or 1.00.

[0070] n is the degree of polymerization, n=Mw / Mr, and n is an integer from 3 to 2000. Mw is the weight average molecular weight of the polymer obtained by gel permeation chromatography, and Mr is the relative molecular mass of the repeating unit of the polymer.

[0071] In one or more embodiments, n is 3 to 2000; preferably, n is 100 to 1800; more preferably, n is 200 to 1500; more preferably, n is 300 to 1300; more preferably, n is 390 to 1230; more preferably, n is 200 to 300, 300 to 400, 400 to 500, 500 to 600, 600 to 700, 700 to 800, 800 to 900, 900 to 1000, 1000 to 1100, 1100 to 1200, 1200 to 1300, 1300 to 1400 or 1400 to 1500.

[0072] Herein, the aromatic group refers to a group containing an aromatic ring.

[0073] Preferably, Ar1 is a tetravalent group containing two benzene rings.

[0074] More preferably, Ar1 is selected from one or more of the following groups:

[0075]

[0076] In some preferred embodiments, Ar1 is selected from one or two of the following groups:

[0077]

[0078] Preferably, Ar2 is a divalent group containing multiple benzene rings and one or more ether bonds, for example a divalent group containing two benzene rings and one ether bond. Herein, the ether bond is generally used as a group connecting two benzene rings. More preferably, Ar2 is a divalent group containing two benzene rings and an ether bond is used as a group connecting two benzene rings. In the present invention, by introducing an ether bond as a flexible group into Ar2, the adhesion between the photoresist and copper and the toughness after curing can be improved.

[0079] More preferably, Ar2 is selected from one or more of the following groups:

[0080]

[0081] In some preferred embodiments, Ar2 is selected from one or two of the following groups:

[0082]

[0083] In some preferred embodiments, Ar1 is Ar2 is In some preferred embodiments, Ar1 is Ar2 is In some preferred embodiments, Ar1 is Ar2 is

[0084]

[0085] In some preferred embodiments, Ar1 is Ar2 is

[0086]

[0087] In some preferred embodiments, Ar1 is Ar2 is

[0088]

[0089] In some preferred embodiments, Ar1 is Ar2 is

[0090]

[0091] Preparation method of negative photosensitive polyimide resin

[0092] The present invention also provides a method for preparing a negative photosensitive polyimide resin, comprising the following steps:

[0093] (1) dissolving a diamine monomer in an organic solvent, adding a dianhydride monomer, and performing a polymerization reaction at -5°C to 10°C for 8 to 14 hours to obtain a polyamic acid liquid;

[0094] (2) washing and drying the polyamic acid liquid to obtain a polyamic acid solid. Dissolving the polyamic acid solid in an organic solvent to obtain an intermediate;

[0095] (3) adding a dehydrating agent and a catalyst to the intermediate, stirring at room temperature for 4 to 10 hours to carry out a dehydration imidization reaction to obtain a negative photosensitive polyimide resin X;

[0096] (4) adding a photosensitive tertiary amine to the negative photosensitive polyimide resin and stirring at room temperature for 6 to 12 hours to obtain a negative photosensitive polyimide resin Y;

[0097] In the present invention, the structure of the dianhydride monomer is wherein Ar1 is as defined in any embodiment herein; and the structure of the diamine monomer is H2N-Ar2-NH2, wherein Ar2 is as defined in any embodiment herein.

[0098] The unit structure of the negative photosensitive polyimide resin X is shown in formula (II);

[0099]

[0100] The unit structure of the negative photosensitive polyimide resin Y is shown in formula (I), wherein the proportion of the unit structure shown in formula (II) in Y is x, and the proportion of the unit structure shown in formula (III) in Y is (1-x);

[0101]

[0102] In some preferred embodiments, the dianhydride monomer is selected from one or more of the following compounds:

[0103]

[0104] In some preferred embodiments, the diamine monomer is selected from one or more of the following compounds:

[0105]

[0106]

[0107] In step (1) and step (2), the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, N-methylpyrrolidone, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether, propylene glycol monomethyl ether, and isopropanol; more preferably, it is one or more of N,N-dimethylformamide, N-methylpyrrolidone, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and isopropanol.

[0108] In step (1), the molar ratio of the dianhydride monomer to the diamine monomer is (1.0-1.1):1, preferably 1.01:1, 1.05:1, 1.08:1, 1.10:1.

[0109] In step (1), the reaction temperature is -5°C to 10°C, preferably 0°C to 5°C, more preferably 0°C, 1°C, 2°C, 3°C, 4°C or 5°C. In step (1), the reaction time is 8 to 14h, preferably 8 to 12h, more preferably 8h, 9h, 10h, 11h or 12h.

[0110] The mass of the polyamic acid in the intermediate of step (2) is 10wt% to 50wt% of the total mass of the intermediate, preferably 15wt% to 40wt%, more preferably 20 to 35wt%, more preferably 25 to 32wt%, more preferably 25 to 26wt% or 31 to 32wt%.

[0111] In step (3), the reaction temperature is 0°C to 30°C, preferably 5°C to 25°C, more preferably 5°C, 10°C, 15°C, 20°C or 25°C. In step (3), the reaction time is 4 to 10 hours, preferably 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours. Controlling the reaction temperature and reaction time of step (3) within the above range is conducive to obtaining a negative photosensitive polyimide resin with good solubility, greater stability and better performance.

[0112] In step (3), the catalyst is selected from one or more of triethylamine, pyridine, diethylethanolamine, quinoline and isoquinoline. Preferably, the catalyst is pyridine. The dehydrating agent is selected from one or more of acetic anhydride, maleic anhydride, trifluoroacetic anhydride and N, N'-dicyclohexylcarbodiimide. Preferably, the dehydrating agent is one or both of acetic anhydride and N, N'-dicyclohexylcarbodiimide.

[0113] The present invention adds a photosensitive tertiary amine in step (4), which can introduce a photosensitive group into the carboxyl group of the polyamic acid through ionic bonding, and can also improve the mechanical properties of the photoresist cured film made of the negative photosensitive polyimide resin and enhance its toughness.

[0114] In step (4), the photosensitive tertiary amine is selected from one or more of N-methyldiethanolamine, N-ethyldiethanolamine, N-methyl-4-aminobenzoate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate.

[0115] In step (4), the mass ratio of the photosensitive tertiary amine to the polyamic acid solid is 1:(1-2.5), preferably 1:1, 1:1.5, 1:1.67, 1:2 or 1:2.5.

[0116] In step (4), the reaction temperature is 0°C to 30°C, preferably 5°C to 25°C, more preferably 5°C, 10°C, 15°C, 20°C or 25°C. In step (4), the reaction time is 6 to 12h, preferably 6h, 7h, 8h, 9h, 10h, 11h or 12h.

[0117] Negative photosensitive polyimide photoresist composition

[0118] The negative photosensitive polyimide photoresist composition of the present invention comprises a resin, a crosslinking agent, a photosensitizer, a photoinitiator and a solvent, wherein the resin comprises the negative photosensitive polyimide resin of the present invention, or the resin is the negative photosensitive polyimide resin of the present invention. In one or more embodiments, the negative photosensitive polyimide photoresist composition of the present invention consists of a negative photosensitive polyimide resin, a crosslinking agent, a photosensitizer, a photoinitiator and a solvent.

[0119] The negative photosensitive polyimide photoresist composition of the present invention can be directly used as a photoresist.

[0120] In the present invention, based on the total weight of the negative photosensitive polyimide photoresist composition, the content of the resin in the negative photosensitive polyimide photoresist composition is 10wt%-50wt%, the content of the organic solvent is 40wt%-85wt%, the content of the crosslinking agent is 0.1wt%-5wt%, the content of the photosensitizer is 1wt%-10wt%, and the content of the photoinitiator is 1wt%-10wt%. Controlling the content of the resin in the negative photosensitive polyimide photoresist composition within the aforementioned range is beneficial to improving the thickness uniformity of the photoresist composition when it is coated. Adding a crosslinking agent to the negative photosensitive polyimide photoresist composition is beneficial to improving the clarity and integrity of the photoresist film pattern after photolithography curing.

[0121] In one or more embodiments, based on the total weight of the negative photosensitive polyimide photoresist composition, the resin content in the negative photosensitive polyimide photoresist composition is preferably 15wt%-45wt%, more preferably 20wt%-40wt%, more preferably 25wt%-35wt%, more preferably 25wt%, 30wt% or 35wt%.

[0122] In one or more embodiments, based on the total weight of the negative photosensitive polyimide photoresist composition, the content of the crosslinker in the negative photosensitive polyimide photoresist composition is preferably 0.2wt%-0.8wt%, more preferably 0.3wt%-0.5wt%, for example 0.3wt%, 0.35wt%, 0.4wt%, 0.45wt%, 0.5wt%.

[0123] In one or more embodiments, based on the total weight of the negative photosensitive polyimide photoresist composition, the content of the photosensitizer in the negative photosensitive polyimide photoresist composition is preferably 1wt%-6wt%, more preferably 2wt%-5wt%, more preferably 2wt%-4wt%, more preferably 2wt%, 3wt% or 4wt%.

[0124] In one or more embodiments, based on the total weight of the negative photosensitive polyimide photoresist composition, the content of the photoinitiator in the negative photosensitive polyimide photoresist composition is preferably 1wt%-10wt%, more preferably 2wt%-8wt%, more preferably 4wt%, 5wt%, 6wt% or 7wt%.

[0125] In the present invention, based on the total weight of the negative photosensitive polyimide photoresist composition, the content of solvent in the negative photosensitive polyimide photoresist composition is preferably 40wt%-75wt%, more preferably 40wt%, 41wt%, 45wt%, 46wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt% or 75wt%.

[0126] When negative photoresist is exposed to UV light or electron beam, the photoinitiator in the photoresist absorbs light energy and generates free radicals. The free radicals attack the double bonds of the acrylic crosslinker, causing the acrylate groups to open and form new free radicals. These free radicals further initiate the polymerization of the acrylate groups to form long-chain polymers.

[0127] The photoinitiator suitable for the present invention can absorb light energy and generate free radicals when the negative photoresist is exposed to ultraviolet light or electron beam, such as oxime ester compounds, and the suitable crosslinking agent is selected from one or more of 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), etc. Preferably, the photoinitiator is 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime).

[0128] The crosslinking agent suitable for the present invention is an acrylic acid or methacrylic acid compound that can react with the free radicals generated by the photoinitiator to form new free radicals, further initiate polymerization reaction and form long-chain polymers. Suitable crosslinking agents are selected from one or more of glycidyl methacrylate, trivinyl methacrylate, polyethylene glycol dimethacrylate, ethylene glycol diacrylate and hexafluoroacrylate. Preferably, the crosslinking agent is ethylene glycol diacrylate.

[0129] The photosensitizer applicable to the present invention may be a benzophenone compound. Suitable photosensitizers are selected from one or more of benzophenone, 4,4'-diaminobenzophenone and dimethylaminobenzophenone compounds. Preferably, the photosensitizer is Michler's ketone.

[0130] The solvent suitable for the negative photosensitive polyimide photoresist composition of the present invention is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, N-methylpyrrolidone, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether, propylene glycol monomethyl ether, and isopropyl alcohol.

[0131] Low temperature curing may be curing at 200° C. or lower (eg, 180° C. or lower).

[0132] Application of negative photosensitive polyimide photoresist composition

[0133] The negative photosensitive polyimide photoresist composition of the present invention can be applied in semiconductor packaging technology, including being used for preparing a buffer protection layer, a rewiring layer, an interlayer insulating film, a cavity structure, etc.

[0134] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples can all be purchased through commercial routes. In the examples and comparative examples of the present invention, infrared spectroscopy is used to characterize the products in the preparation process.

[0135] Example 1: Synthesis of negative photosensitive polyimide photoresist resin R1

[0136] The negative photosensitive polyimide photoresist resin R1 was prepared according to the following steps:

[0137] S1: Under a dry nitrogen flow, 26.668 g of N,N-dimethylformamide (DMF) was added to a three-necked flask, and then 0.01 mol (2.00241 g) of a diamine monomer (4,4′-diaminodiphenyl ether) was added under stirring, and the mixture was stirred at room temperature for 0.5 to 1 h until the diamine monomer was completely dissolved. Then, 0.0105 mol (4.66452 g) of a dianhydride monomer (hexafluorodianhydride) was added three times under stirring, each time with an interval of 0.5 to 1 h, and the mixture was reacted at 0° C. for 8 to 10 h to perform a polymerization reaction to obtain a polyamic acid;

[0138] S2: After the polymerization reaction is completed, cool to room temperature, slowly pour the obtained viscous polymer solution into a large amount of methanol and deionized water mixed washing liquid (the volume ratio of methanol to deionized water is 1: (1-3)), wash thoroughly 3 times, discard the washing liquid after each washing, and then use a vacuum oven to dry at 60°C for 24 hours to obtain a polyamic acid solid; weigh 30g of polyamic acid solid, dissolve it in an appropriate amount of 41g of organic solvent to obtain an intermediate. The organic solvent is selected from N,N-dimethylformamide, N-methylpyrrolidone, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether or isopropanol;

[0139] S3: Weigh an appropriate amount of 2.25g of dehydrating agent (acetic anhydride) and 3.375g of catalyst (pyridine), and premix the two, then add the premixed liquid to the intermediate obtained in S2, and react at room temperature in the dark for 4 to 5h to perform dehydration imidization reaction to obtain a negative photosensitive polyimide resin;

[0140] The infrared absorption spectrum of the obtained polymer solid was measured. Figure 1 As shown, at 1659cm -1 The amide I band and amide II band of the amide group were detected nearby, namely the carbonyl stretching vibration, NH angle vibration and C—N stretching vibration in the amide group. -1 The C=O stretching vibration of the aromatic acid carboxyl group was detected nearby at 2900-3200 cm-1 There is a faint characteristic peak of amidic acid nearby.

[0141] S4: Add 15 g of photosensitive tertiary amine (dimethylaminoethyl methacrylate) dropwise into the negative photosensitive polyimide resin in a light-proof environment. After the addition is completed, stir at room temperature for 8 to 10 hours to introduce the photosensitive tertiary amine into the carboxyl group of the polyamic acid through ionic bonding to obtain a negative photosensitive polyimide photoresist resin R1.

[0142] Example 2: Synthesis of negative photosensitive polyimide photoresist resin R2

[0143] The synthesis method of the negative photosensitive polyimide photoresist resin R2 of this embodiment is basically the same as that of Embodiment 1, except that the diamine monomer used in step S1 is 2,2′-bis(trifluoromethyl)-4,4′-diaminophenyl ether, and the dianhydride monomer is 3,3′,4,4′-biphenyltetracarboxylic dianhydride.

[0144] Example 3: Synthesis of negative photosensitive polyimide photoresist resin R3

[0145] The synthesis method of the negative photosensitive polyimide photoresist resin R3 of this embodiment is basically the same as that of the embodiment 1, except that the polymerization reaction in step S1 is carried out at 0° C. for 12 hours.

[0146] Example 4: Synthesis of negative photosensitive polyimide photoresist resin R4

[0147] The synthesis method of the negative photosensitive polyimide photoresist resin R4 of this embodiment is basically the same as that of the embodiment 1, except that the polymerization reaction condition in step S1 is to react at -5°C for 8 to 10 hours.

[0148] Example 5: Synthesis of negative photosensitive polyimide photoresist resin R5

[0149] The synthesis method of the negative photosensitive polyimide photoresist resin R5 of this embodiment is basically the same as that of Example 1, except that the amount of the polyamic acid solid used as the intermediate in step S2 is 25 g, the amount of the organic solvent is 46 g, and other raw materials and process parameters remain unchanged.

[0150] Example 6: Synthesis of negative photosensitive polyimide photoresist resin R6

[0151] The synthesis method of the negative photosensitive polyimide photoresist resin R6 of this embodiment is basically the same as that of the embodiment 1, except that the amount of the photosensitive tertiary amine dimethylaminoethyl methacrylate in step S4 is 10 g.

[0152] Example 7: Synthesis of negative photosensitive polyimide photoresist resin R7

[0153] The synthesis method of the negative photosensitive polyimide photoresist resin R7 of this embodiment is basically the same as that of the embodiment 1, except that the dehydrating agent in step S3 is dicyclohexylcarbodiimide.

[0154] Example 8: Synthesis of negative photosensitive polyimide photoresist resin R8

[0155] The synthesis method of the negative photosensitive polyimide photoresist resin R8 of this embodiment is basically the same as that of Embodiment 1, except that the amount of the dehydrating agent in step S3 is 1.8 g.

[0156] Example 9: Synthesis of negative photosensitive polyimide photoresist resin R9

[0157] The synthesis method of the negative photosensitive polyimide photoresist resin R9 of this embodiment is basically the same as that of Embodiment 1, except that the diamine monomer used in step S1 is 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and the dianhydride monomer is 4,4′-oxydiphthalic anhydride.

[0158] Example 10: Synthesis of negative photosensitive polyimide photoresist resin R10

[0159] The synthesis method of the negative photosensitive polyimide photoresist resin R10 of this embodiment is basically the same as that of Example 1, except that the 4,4'-diaminodiphenyl ether in step S1 is replaced by an equal amount of 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, and the dianhydride monomer is replaced by an equal amount of 3,3',4,4'-dibenzophenone tetracarboxylic dianhydride.

[0160] Example 11: Synthesis of negative photosensitive polyimide photoresist resin R11

[0161] The synthesis method of the negative photosensitive polyimide photoresist resin R11 of this embodiment is basically the same as that of Example 1, except that the 2,2-bis(4-hydroxy-3-aminophenyl)propane in step S1 is replaced by an equal amount of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, and the hexafluorodianhydride is replaced by an equal amount of 3,3',4,4'-biphenyltetracarboxylic dianhydride.

[0162] Example 12: Synthesis of negative photosensitive polyimide photoresist resin R12

[0163] The synthesis method of the negative photosensitive polyimide photoresist resin R12 of this embodiment is basically the same as that of Embodiment 1, except that the diamine monomer used in step S1 is 4,4'-bis(4-aminophenyloxy)biphenyl, and the dianhydride monomer is 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride.

[0164] Example 13: Synthesis of negative photosensitive polyimide photoresist resin R13

[0165] The synthesis method of the negative photosensitive polyimide photoresist resin R13 of this embodiment is basically the same as that of Embodiment 1, except that the diamine monomer used in step S1 is 4,4'-di(3-aminophenoxy)biphenyl, and the dianhydride monomer is 3,3,4,4-diphenylsulfonetetracarboxylic dianhydride.

[0166] Example 14: Synthesis of negative photosensitive polyimide photoresist resin R14

[0167] The synthesis method of the negative photosensitive polyimide photoresist resin R14 of this embodiment is basically the same as that of Embodiment 1, except that the diamine monomer used in step S1 is 4,4'-bis(3-aminophenoxy)diphenyl sulfone, and the dianhydride monomer is 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride.

[0168] Comparative Example 1: Synthesis of Negative Photosensitive Polyimide Photoresist Resin R15

[0169] The synthesis method of the negative photosensitive polyimide photoresist resin R15 of this embodiment is basically the same as that of Embodiment 1, except that the 4,4'-diaminodiphenyl ether in step S1 is changed to 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether.

[0170] Comparative Example 2: Synthesis of Negative Photosensitive Polyimide Photoresist Resin R16

[0171] The synthesis method of the negative photosensitive polyimide photoresist resin R16 of this embodiment is basically the same as that of Embodiment 1, except that the addition method of dimethylaminoethyl methacrylate in step 4 of the synthesis of the negative photosensitive polyimide photoresist resin is changed from dripping to pouring.

[0172] Comparative Example 3: Synthesis of Negative Photosensitive Polyimide Photoresist Resin R17

[0173] The synthesis method of the negative photosensitive polyimide photoresist resin R17 of this embodiment is basically the same as that of the embodiment 1, except that the dehydrating agent in the synthesis step 3 of the negative photosensitive polyimide photoresist resin is changed to triethylamine.

[0174] Comparative Example 4: Synthesis of Negative Photosensitive Polyimide Photoresist Resin R18

[0175] The synthesis method of the negative photosensitive polyimide photoresist resin R18 of this embodiment is substantially the same as that of the embodiment 1, except that the amount of the polyamic acid solid in step S2 of the negative photosensitive polyimide photoresist resin is modified to 20 g.

[0176] Comparative Example 5: Synthesis of Negative Photosensitive Polyimide Photoresist Resin R19

[0177] The synthesis method of the negative photosensitive polyimide photoresist resin R19 of this embodiment is basically the same as that of Embodiment 1, except that the amount of the dehydrating agent in step S3 is 1 g.

[0178] Comparative Example 6: Synthesis of Negative Photosensitive Polyimide Photoresist Resin R20

[0179] The synthesis method of the negative photosensitive polyimide photoresist resin R20 of this embodiment is basically the same as that of the embodiment 1, except that the amount of the photosensitive tertiary amine dimethylaminoethyl methacrylate in step S4 is 20 g.

[0180] Comparative Example 7: Synthesis of Negative Photosensitive Polyimide Photoresist Resin R21

[0181] The synthesis method of the negative photosensitive polyimide photoresist resin R21 of this embodiment is basically the same as that of the embodiment 1, except that the polymerization reaction condition in step S1 is to react at 30° C. for 8 hours.

[0182] For the sake of clarity, the diamine monomers and dianhydride monomers of some examples and comparative examples are listed in Table 1, and the synthesis parameters of the negative photosensitive polyimide photoresist resins of some examples and comparative examples are listed in Tables 2 and 3.

[0183] Table 1: Monomers used in the synthesis of negative photosensitive polyimide photoresist resins

[0184]

[0185]

[0186]

[0187] Table 2: Negative photosensitive polyimide photoresist resin synthesis parameters

[0188]

[0189]

[0190] Table 3: Negative photosensitive polyimide photoresist resin synthesis parameters

[0191]

[0192]

[0193] Example 15: Compounding of negative photosensitive polyimide photoresist P1

[0194] 3 g (3 wt %) of photosensitizer, 0.375 g (0.375 wt %) of cross-linking agent and 5 g (5 wt %) of photoinitiator were added to the solution of negative photosensitive polyimide photoresist resin R1 prepared in Example 1 (containing 30 g (30 wt %) of polyamic acid, 41 g (41 wt %) of solvent, 15 g (15 wt %) of photosensitive tertiary amine, 2.25 g (2.25 wt %) of dehydrating agent and 3.375 g (3.375 wt %) of catalyst) and fully dissolved and uniformly mixed to obtain negative photosensitive polyimide photoresist P1, wherein the photosensitizer is (Michler's ketone), crosslinking agent is (ethylene glycol diacrylate), and the photoinitiator was 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime) (OXE01).

[0195] Examples 16-28: Compounding of negative photosensitive polyimide photoresists P2-P14

[0196] The compounding method of negative photosensitive polyimide photoresist P2-P14 is different from the compounding method of negative photosensitive polyimide photoresist P1 in that the solution containing negative photosensitive polyimide photoresist resin R1 prepared in Example 1 is modified to a solution containing negative photosensitive polyimide photoresist resin R2-R14 prepared in any one of Examples 2-14.

[0197] Example 29: Compounding of negative photosensitive polyimide photoresist P22

[0198] The compounding method of the negative photosensitive polyimide photoresist P22 is different from the compounding method of the negative photosensitive polyimide photoresist P1 in that the cross-linking agent in Example 15 is replaced with hexafluoroacrylate of the same mass, and other raw materials and process parameters remain unchanged.

[0199] Comparative Examples 8-14: Compounding of Negative Photosensitive Polyimide Photoresists P15-P21

[0200] The compounding method of negative photosensitive polyimide photoresist P15-P21 is different from the compounding method of negative photosensitive polyimide photoresist P1 in that the solution containing negative photosensitive polyimide photoresist resin R1 prepared in Example 1 is modified to a solution containing negative photosensitive polyimide photoresist resin R15-R21 prepared in any one of Comparative Examples 1-7.

[0201] Comparative Example 15: Compounding of negative photosensitive polyimide photoresist P23

[0202] The compounding method of the negative photosensitive polyimide photoresist P23 is different from the compounding method of the negative photosensitive polyimide photoresist P1 in that no cross-linking agent is added in the compounding of the negative photosensitive polyimide photoresist, and other raw materials and process parameters remain unchanged.

[0203] Comparative Example 16: Compounding of Negative Photosensitive Polyimide Photoresist P24

[0204] The compounding method of negative photosensitive polyimide photoresist P24 is different from the compounding method of negative photosensitive polyimide photoresist P1 in that no photosensitizer is added in the compounding of the negative photosensitive polyimide photoresist, and other raw materials and process parameters remain unchanged.

[0205] For the sake of clarity, the photoresist compounding parameters of some embodiments and comparative examples are listed in Table 4.

[0206] Table 4: Negative photosensitive polyimide photoresist compounding parameters

[0207]

[0208]

[0209] Example 23: Photolithography curing process and copper adhesion test

[0210] Photolithography development and curing

[0211] About 5 g of a negative photosensitive polyimide photoresist selected from the aforementioned P1-P24 is dropped onto a 4-inch silicon wafer at a time, spin-coated at a spin-coating speed of 1800 rpm, and baked on a hot plate at 100°C for 180 seconds to remove most of the solvent. The film thickness uniformity is measured using a profilometer to ensure that it is within the range of ±0.1 μm. Then, a stepper photolithography machine was used for photolithography. After the photolithography was completed, standard N-methylpyrrolidone (NMP) developer was used for development at 25°C for 120 seconds. After development, the surface was rinsed clean with deionized water and nitrogen. The film was baked on a hot plate at 110°C for 180 seconds to allow the film surface to quickly undergo a cross-linking reaction to prevent the pattern from flowing. The film was cured in an oven under a nitrogen atmosphere. The temperature curve was as follows: heating from 50°C to 110°C (heating rate 2°C / min), maintained at 110°C for 30 minutes, then heated from 110°C to 180°C (heating rate 2°C / min), maintained at 180°C for 60 minutes, cooled from 180°C to 80°C (cooling rate 1°C / min), and finally cooled from 80°C to 40°C (cooling rate 1°C / min), and the curing was completed.

[0212] The infrared absorption spectrum of the photoresist film after curing of the photoresist P1 obtained in Example 15 was measured, and the results are as follows: Figure 2 shown.

[0213] Adhesion test with copper

[0214] 5 g of a negative photosensitive polyimide photoresist selected from the above P1-P24 is dripped onto a 4-inch silicon wafer after copper plating by physical vapor deposition (PVD), and spin-coated at a spin-coating speed of 1800 rpm, and then baked on a hot plate at 110°C for 180 seconds to remove most of the solvent, and cured in an oven under a nitrogen atmosphere, and the temperature curve is as follows: heating from 50°C to 110°C (heating rate 2°C / min), holding for 30 minutes, then heating from 110°C to 180°C (heating rate 2°C / min), holding for 60 minutes, cooling from 120°C to 80°C (cooling rate 1°C / min), and finally cooling from 80°C to 40°C (cooling rate 1°C / min); The surface of the solidified photoresist is plated with a layer of copper by PVD; the spin coating and pre-baking steps are repeated once, and the cooled silicon wafer is placed in a stepper photolithography machine; the exposed silicon wafer is developed at 25° C. using a standard N-methylpyrrolidone (NMP) developer for 120 seconds, and the developed silicon wafer is placed in 5% sulfuric acid for 10 seconds, rinsed with water, and blown dry with nitrogen; then the silicon wafer is electroplated for 10 minutes (copper plating) with a current density of 1; the electroplated silicon wafer is washed and blown dry, and then immersed in a degumming solution (NMP) for degumming until the surface photoresist is completely removed; the degummed silicon wafer is washed and blown dry, and a transparent tape is attached to the electroplated pattern, and the tape is instantly torn off, and the ratio of the number of patterns that are stuck to the total number of patterns is the stripping rate.

[0215] The test results of x and n values ​​of the polymer resin in the photoresist of some embodiments and comparative examples are shown in Table 5 below:

[0216] Table 5: x and n values ​​of polymer resins in some photoresists

[0217] Example / Comparative Example x n Example 15 (Photoresist P1) 0.83 756 Example 16 (Photoresist P2) 0.86 833 Example 17 (Photoresist P3) 0.79 933 Example 18 (Photoresist P4) 0.78 644 Example 19 (Photoresist P5) 0.82 745 Example 20 (Photoresist P6) 0.88 762 Example 21 (Photoresist P7) 0.91 815 Example 22 (Photoresist P8) 0.82 679 Example 23 (Photoresist P9) 0.82 390 Example 24 (Photoresist P10) 0.85 613 Example 25 (Photoresist P11) 0.81 1230 Example 29 (Photoresist P22) 0.81 548 Comparative Example 8 (Photoresist P15) 0.76 774 Comparative Example 9 (Photoresist P16) 0.60 879 Comparative Example 10 (Photoresist P17) 0.63 792 Comparative Example 11 (Photoresist P18) 0.93 771 Comparative Example 12 (Photoresist P19) 0.41 445 Comparative Example 13 (Photoresist P20) 0.33 537 Comparative Example 14 (Photoresist P21) 0.63 390 Comparative Example 15 (Photoresist P23) 0.98 758

[0218] The photolithography curing process and copper adhesion test results and corresponding analysis results are as follows:

[0219] Photoresists P1-P7 can display clear and complete patterns after photolithography and curing at 180°C. The film thickness is controlled at 1μm~10μm, the minimum line width is stable at around 5μm, the pattern stripping rate of 5μm~25μm is less than 15%, and the pattern stripping rate of 25μm~160μm is less than 0.7%. There is no brittleness of the photoresist film after the photolithography curing process.

[0220] Photoresist P8 produced a small amount of cracks after exposure, and the stability of the photoresist after negative matching was slightly reduced.

[0221] The viscosity of the polyamic acid in Example 9 is significantly increased compared with Example 1. During the compounding of the photoresist P9, slight cracking occurs due to stress during post-baking.

[0222] Photoresist P10 can produce a pattern after alignment and exposure. The pattern is clearer after development, but the development speed is slightly faster.

[0223] After exposure and development of photoresist P11, the sensitivity of some patterns is low and the accuracy is slightly low.

[0224] The photoresist P22 has a complete and clear photolithography pattern and is fully developed within 1 minute.

[0225] In Comparative Example 1, when the polyamic acid solid was redissolved, the 30% solution had a high viscosity, and after adding the mixed solution of the dehydrating agent and the catalyst, it was in a green gel state, which affected the processing performance of the photoresist and reduced the film thickness after the photolithography curing process. Therefore, compared with any one of the photoresists P1-P7, the stability of the subsequent process of the photoresist P15 obtained in Comparative Example 8 was affected.

[0226] In Comparative Example 2, after pouring dimethylaminoethyl methacrylate, the viscosity of the solution increased sharply, and the solution appeared as white turbid agglomerates with extremely poor uniformity, resulting in that the photoresist P16 obtained in Comparative Example 9 could not be used for photolithography.

[0227] Compared with any of the photoresists P1-P7, the photoresist P17 obtained in Comparative Example 10 has a significantly reduced contrast ratio after curing and cannot show a clear and complete pattern.

[0228] Compared with any of the photoresists P1-P7, the photoresist P18 obtained in Comparative Example 11 has a too small film thickness of only about 0.8 μm after using the photolithography curing process.

[0229] The photoresist P19 obtained in Comparative Example 12 was rapidly dissolved in the developer in both the exposed area and the non-exposed area, and no pattern could be revealed.

[0230] In the process of adding photosensitive tertiary amine in Comparative Example 6, the viscosity of the solution first increased and became close to a gel state, and then became a clear and flowing state, resulting in poor contrast and unclear pattern of the photoresist P20 obtained in Comparative Example 13 after development.

[0231] The photoresist P21 obtained in Comparative Example 14 has a low contrast after development, and the thickness difference between the exposed area and the non-exposed area is too low.

[0232] The mechanical properties of the photoresist film of the photoresist P23 obtained in Comparative Example 15 were greatly reduced after the photolithography curing process, resulting in brittleness. The development rate in the developer was too fast to be controlled, and a large number of cracks occurred in the pattern after the photolithography curing process.

[0233] In summary, the negative photosensitive polyimide photoresist of the present invention has excellent low-temperature curing properties and adhesion to copper, and better meets the application requirements of semiconductor packaging materials.

[0234] The above implementation scheme is only for illustrating the technical concept and features of the present invention, and its purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A negative photosensitive polyimide resin, It is characterized in that The negative photosensitive polyimide resin has a structure shown in Formula I: Among them, Ar 1 It is a tetravalent group containing two benzene rings; Ar 2 It is a divalent group containing two or more benzene rings and one or more ether bonds; x=(S 1659 / S 1500 ) T / (S 1659 / S 1500 ) T’ , x is 0.78~0.91; Among them (S 1659 / S 1500 ) T The infrared spectrum of negative photosensitive polyimide resin is at 1659cm -1 The characteristic peak area at 1500cm -1 The ratio of the characteristic peak areas at 1659 / S 1500 ) T’ The infrared spectrum of the polymer after being treated with a dehydrating agent and a catalyst is at 1659 cm -1 The characteristic peak area at 1500cm -1 The ratio of the characteristic peak areas at n=Mw / Mr, n is 300~1300; Wherein Mw is the weight average molecular weight of the polymer obtained by gel permeation chromatography, and Mr is the relative molecular mass of the repeating unit of the polymer.

2. The negative photosensitive polyimide resin according to claim 1, It is characterized in that Ar 1 One or more selected from the following groups:

3. The negative photosensitive polyimide resin according to claim 1, It is characterized in that Ar 2 Select one or more of the following:

4. The negative photosensitive polyimide resin according to claim 1, It is characterized in that Ar 1 One or more selected from the following groups: Moreover, Ar 2 One or more selected from the following groups:

5. A method for preparing the negative photosensitive polyimide resin according to any one of claims 1 to 4, Features The following steps are involved: (1) dissolving a diamine monomer in an organic solvent, adding a dianhydride monomer, and performing a polymerization reaction at -5°C to 10°C for 8 to 14 hours to obtain a polyamic acid liquid; (2) washing and drying the polyamic acid liquid to obtain a polyamic acid solid; dissolving the polyamic acid solid in an organic solvent to obtain an intermediate, wherein the mass of the polyamic acid in the intermediate is 10 wt% to 50 wt% of the total mass of the intermediate; (3) adding a dehydrating agent and a catalyst to the intermediate, stirring at room temperature for 4 to 10 hours to carry out a dehydration imidization reaction to obtain a negative photosensitive polyimide resin X; (4) adding a photosensitive tertiary amine to the negative photosensitive polyimide resin and stirring at room temperature for 6 to 12 hours to obtain a negative photosensitive polyimide resin Y; Wherein, the structure of the dianhydride monomer is The structure of the diamine monomer is H 2 N-Ar 2 -NH 2 ; The unit structure of the negative photosensitive polyimide resin X is shown in formula (II); The unit structure of the negative photosensitive polyimide resin Y is shown in formula (I), wherein the proportion of the unit structure shown in formula (II) in Y is x, and the proportion of the unit structure shown in formula (III) in Y is (1-x); 6. The method according to claim 5, It is characterized in that In step (1), the molar ratio of the dianhydride monomer to the diamine monomer is (1.01-1.1):1; In steps (1) and (2), the organic solvent is selected from N,N-dimethylformamide, N,N-dimethylethyl Amide, γ-butyrolactone, N-methylpyrrolidone, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate Esters, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether, propylene glycol monomethyl ether, One or more of propanol; In step (3), the dehydrating agent is selected from acetic anhydride, maleic anhydride, trifluoroacetic anhydride and N,N'- One or more of dicyclohexylcarbodiimide; the catalyst is selected from one or more of triethylamine, pyridine, diethylethanolamine, quinoline and isoquinoline; the reaction temperature is 0-30°C.

7. The method according to claim 5, It is characterized in that In step (4), the mass ratio of the photosensitive tertiary amine to the polyamic acid solid in the intermediate is 1:(1-2.5); the reaction temperature is 0°C-30°C; the photosensitive tertiary amine is selected from one or more of N-methyldiethanolamine, N-ethyldiethanolamine, N-methyl-4-aminobenzoate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate.

8. A negative photosensitive polyimide photoresist composition, It is characterized in that The photoresist composition comprises the negative photosensitive polyimide resin Y according to any one of claims 1 to 4, and also comprises an organic solvent, a crosslinking agent, a photosensitizer and a photoinitiator; Based on the total mass of the negative photosensitive polyimide photoresist composition, in the photoresist composition, the content of the negative photosensitive polyimide resin Y is 10wt%-50wt%, the content of the organic solvent is 40wt%-85wt%, the content of the crosslinker is 0.1wt%-5wt%, the content of the photosensitizer is 1wt%-10wt%, and the content of the photoinitiator is 1wt%-10wt%.

9. The negative photosensitive polyimide photoresist composition according to claim 8, It is characterized in that The organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, N-methylpyrrolidone, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether, propylene glycol monomethyl ether, and isopropanol; The cross-linking agent is a compound having a methacrylic acid structure or an acrylic acid structure, selected from one or more of glycidyl methacrylate, trivinyl methacrylate, polyethylene glycol dimethacrylate, ethylene glycol diacrylate and hexafluoroacrylate; The photosensitizer is a compound having a benzophenone structure, selected from one or more of benzophenone, 4,4'-diaminobenzophenone and (dimethylamino)benzophenone compounds; The photoinitiator is a compound containing a benzophenone structure / imidazole structure / oxime ester structure, selected from one or more of 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, and 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime).

10. Use of the negative photosensitive polyimide photoresist composition according to claim 8 or 9 in semiconductor packaging.

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