CN114805805A

CN114805805A - Polyimide with high bonding strength and preparation method and application thereof

Info

Publication number: CN114805805A
Application number: CN202210493965.3A
Authority: CN
Inventors: 张国平; 钟澳; 李金辉; 孙蓉
Original assignee: Shenzhen Institute of Advanced Technology of CAS; Shenzhen Institute of Advanced Electronic Materials
Current assignee: Shenzhen Institute of Advanced Electronic Materials
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-07-29
Anticipated expiration: 2042-04-29
Also published as: CN114805805B

Abstract

The invention provides polyimide with high adhesive strength, a preparation method and application thereof. According to the invention, through molecular chain structure design, a structure which has chemical interaction with copper is designed on a side chain of a polyimide molecule, and the polyimide with high bonding strength is prepared, and the preparation method has high selectivity. The polyimide with high bonding strength is applied to the wafer-level chip packaging rewiring structure, the polyimide and the smooth copper surface have high bonding strength, the occurrence of the interface failure phenomenon is prevented, and the polyimide can be used for high-frequency transmission.

Description

Polyimide with high bonding strength and preparation method and application thereof

Technical Field

The invention relates to the field of high polymer materials, in particular to polyimide with high bonding strength, and a preparation method and application thereof.

Background

Polyimide is a rigid chain polymer with a highly regular chemical structure and containing an imide ring on a main chain, has excellent electrical, mechanical and thermal properties, and plays a role in protecting chips and metal circuits in a rewiring process. In the wafer level chip packaging rewiring structure, a copper circuit is continuously refined and the surface is flattened, and the requirement on the bonding strength of polyimide and a smooth copper surface is increasingly improved, so that the performance requirement of the polyimide in the rewiring processing and application process is met, and the occurrence of an interface failure phenomenon is prevented.

In order to solve the problem of interface failure, the prior art generally adopts roughening treatment on the copper surface and addition of a bonding auxiliary agent. The surface roughening treatment of copper has a skin effect, signal transmission is concentrated on a surface thin layer of conductive copper, and the roughness of copper must be below 0.1 μm in order to reduce loss of high-speed high-frequency signals during transmission, so that the adhesion strength of polyimide and copper cannot be increased by roughening copper. The use of the adhesion promoter can improve the adhesion strength between the polyimide and the copper metal layer, but increases the dielectric constant and dielectric loss tangent of the system, and hinders high-frequency transportation. Therefore, research and development of polyimide with high adhesion strength to smooth copper surfaces in wafer-level chip package re-wiring structures is becoming increasingly important.

Disclosure of Invention

In view of the disadvantages of the prior art, a first object of the present invention is to provide a polyimide having high adhesive strength, in which a side chain of a molecular structure of the polyimide has a structure chemically interacting with copper, and the polyimide has high adhesive strength with copper.

The second objective of the present invention is to provide a method for preparing polyimide with high adhesive strength, wherein a molecular chain structure is designed, and a structure having chemical interaction with copper is designed on a side chain of a polyimide molecule, so that the method has high selectivity.

The third objective of the present invention is to provide an application of polyimide with high adhesion strength in a rewiring structure of a wafer level chip package, so as to prevent the occurrence of an interface failure phenomenon.

The invention aims to realize the following steps:

the invention provides a polyimide with high adhesive strength, which has a repeating structural unit shown as a general formula (1), wherein the repeating structural unit contains a structure which has chemical interaction with copper,

in the general formula (1) described above,

represents a dianhydride functional group and a dianhydride functional group,

represents a diamine functional group

The structure with the chemical interaction with the copper is contained in the side chain, and the structure with the chemical interaction with the copper is selected from at least one of nitrogen heterocycle, siloxane, thioether and phosphate.

The invention also provides a preparation method of the polyimide with high bonding strength, which comprises the following steps:

s11, synthesis of polyamic acid: dissolving diamine in a polar organic solvent, adding dianhydride, and synthesizing a first polyamic acid solution;

s12, graft polyamic acid: adding a grafting compound into the first polyamic acid solution to perform a grafting reaction to obtain a second polyamic acid solution;

s13, imidization: performing thermal imidization on the second polyamic acid solution to obtain polyimide with high bonding strength; wherein,

the diamine comprises a diamine monomer I, wherein the diamine monomer I is a diamine monomer containing a reactive grafting structure, and the reactive grafting structure is selected from at least one of hydroxyl, carboxyl, sulfydryl, alkoxy, amido, sulfonic acid group, cyano and halogen atom;

the grafting compound comprises a reactive group capable of reacting with the active grafting structure and a structure with chemical interaction with copper, wherein the reactive group is selected from at least one of hydroxyl, carboxyl, amino, sulfonic acid group and epoxy group, and the structure with chemical interaction with copper is selected from at least one of nitrogen heterocycle, siloxane, thioether and phosphate.

Preferably, the diamine further comprises a diamine monomer II and/or a diamine monomer III, wherein the diamine monomer II is a diamine monomer containing a structure which has chemical interaction with copper; the diamine monomer III is a diamine monomer free of a target structure including the structure having a chemical interaction with copper and the living graft structure.

The invention also provides another preparation method of the polyimide with high bonding strength, which comprises the following steps:

s21, synthesis of polyamic acid: dissolving diamine in a polar organic solvent, adding dianhydride, and synthesizing a first polyamic acid solution;

s22, imidization reaction: adding an imidizing agent and an imidizing accelerator into the first polyamic acid solution to carry out chemical imidization to obtain a first polyimide solution;

s23, precipitating a polyimide pre-solid from the first polyimide solution;

s24, graft polyimide: dissolving the polyimide pre-solid in a polar organic solvent to obtain a second polyimide solution; adding a dehydrating agent and a grafting compound into the second polyimide solution to perform a grafting reaction to obtain a third polyimide solution;

s25, separating out polyimide solid from the third polyimide solution to obtain polyimide with high bonding strength; wherein,

The invention also provides application of the polyimide with high bonding strength in a wafer-level chip packaging rewiring structure, which comprises the following steps: and coating the polyimide on a copper wire with a smooth surface to form a film.

In the polyimide with high adhesion strength provided by the embodiment of the invention, the side chain of the molecular structure of the polyimide contains a structure having a chemical interaction with copper, the structure having a chemical interaction with copper is selected from at least one of nitrogen heterocycles, siloxanes, thioethers and phosphate esters, and the structure having a chemical interaction with copper can chemically interact with copper, so that the polyimide and the copper have high adhesion strength.

In the preparation method of the polyimide with high adhesive strength provided by the embodiment of the invention, a structure which has chemical interaction with copper is designed on a side chain of a polyimide molecule through molecular chain structure design, and the structure which has chemical interaction with copper is selected from at least one of nitrogen heterocycle, siloxane, thioether and phosphate, so that the adhesive strength between the polyimide and a smooth copper surface can be improved. In addition, the structure with chemical interaction with copper is designed in the side chain of the polyimide molecule, so that the adhesive strength can be improved under the condition of not influencing the main chain structure of the polyimide and the good main body performances of heat, mechanics, electricity and the like, meanwhile, the structure and the grafting regulation flexibility of the side chain are high, the structural design of the polyimide molecule is more flexible, and other performances can be improved in a synergistic manner while the adhesive strength is improved. The preparation method of the polyimide with high bonding strength provided by the embodiment of the invention can flexibly select the structure of the side chain and has high selectivity.

According to the embodiment of the invention, the polyimide with high bonding strength is applied to the wafer-level chip packaging rewiring structure, and the polyimide and the smooth copper surface have high bonding strength, so that the interface failure phenomenon is prevented, and the polyimide can be used for high-frequency transmission.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below.

In view of the problem of low adhesion strength between polyimide and copper in the prior art, a first object of the present invention is to provide a polyimide with high adhesion strength, in which a side chain of a molecular structure of the polyimide has a structure that chemically interacts with copper, and has high adhesion strength with copper. The second objective of the present invention is to provide a method for preparing polyimide with high adhesive strength, wherein a molecular chain structure is designed, and a structure having chemical interaction with copper is designed on a side chain of a polyimide molecule, so that the method has high selectivity. The third objective of the present invention is to provide an application of polyimide with high adhesion strength in a rewiring structure of a wafer level chip package, so as to prevent the occurrence of an interface failure phenomenon.

The embodiment of the invention provides polyimide with high bonding strength, which has a repeating structural unit shown as a general formula (1), wherein the repeating structural unit contains a structure which has chemical interaction with copper,

in the general formula (1) described above,

represents a dianhydride functional group and a dianhydride functional group,

represents a diamine functional group

Nitrogen atoms in the nitrogen heterocyclic ring can generate coordination with copper, so that the bonding strength of the polyimide and the copper can be improved; the sulfur atom in the thioether has lone pair electrons with good affinity with metal, so that the polyimide containing a thioether structure has good bonding performance with metal copper; the siloxane has good flexibility and low surface energy, and can have good spreading characteristic on the copper surface so as to improve the bonding strength of the polyimide and the copper; phosphorus in the phosphate contains coordination chemistry, and can generate chemical action with copper to improve the bonding strength of the polyimide and the copper.

The structural design with chemical interaction with copper is arranged in the side chain of the polyimide molecule, so that the adhesive strength can be improved under the condition of not influencing the main chain structure of the polyimide and the good main body performances of thermology, mechanics, electricity and the like, meanwhile, the structure and the grafting regulation flexibility of the side chain are high, the structural design of the polyimide molecule is more flexible, and other performances can be improved in a synergistic manner while the adhesive strength is improved. For example, due to the introduction of a nitrogen-containing heterocycle, hydrogen bonds are generated between molecular chains, intermolecular forces are enhanced, the degree of freedom of the molecular chains is reduced, and polyimide exhibits a low Coefficient of Thermal Expansion (CTE) and residual stress. Meanwhile, the introduction of siloxane enhances the hydrophobicity and dielectric properties of polyimide, so that polyimide exhibits a lower dielectric constant.

The polyimide having high adhesive strength as described above can be produced by the following production method (one) or production method (two).

Wherein, the preparation method (one) comprises the following steps:

step S11, synthesizing polyamic acid: diamine is dissolved in a polar organic solvent, and then dianhydride is added to synthesize a first polyamic acid solution.

Step S12, grafting polyamic acid: and adding a grafting compound into the first polyamic acid solution to perform a grafting reaction to obtain a second polyamic acid solution.

Step S13, imidization: and thermally imidizing the second polyamic acid solution to obtain the polyimide with high bonding strength.

Wherein the preparation method (II) comprises the following steps:

step S21, synthesizing polyamic acid: diamine is dissolved in a polar organic solvent, and then dianhydride is added to synthesize a first polyamic acid solution.

Step S22, imidization: and adding an imidizing agent and an imidizing accelerator into the first polyamic acid solution to carry out chemical imidization to obtain a first polyimide solution.

Step S23, precipitating a polyimide pre-solid from the first polyimide solution.

Step S24, grafting polyimide: dissolving the polyimide pre-solid in a polar organic solvent to obtain a second polyimide solution; and adding a dehydrating agent and a grafting compound into the second polyimide solution to perform a grafting reaction to obtain a third polyimide solution.

And step S25, precipitating polyimide solid from the third polyimide solution to obtain polyimide with high adhesive strength.

Wherein, in the preparation method (one) and the preparation method (two), the diamine comprises a diamine monomer I, the diamine monomer I is a diamine monomer containing a reactive graft structure, and the reactive graft structure is selected from at least one of a hydroxyl group, a carboxyl group, a mercapto group, an alkoxy group, an amide group, a sulfonic group, a cyano group and a halogen atom;

In a preferred embodiment, the diamine in the preparation method (one) and the preparation method (two) further comprises a diamine monomer ii and/or a diamine monomer iii, wherein the diamine monomer ii is a diamine monomer having a structure that chemically interacts with copper; the diamine monomer III is a diamine monomer free of a target structure including the structure having a chemical interaction with copper and the living graft structure.

Specifically, the diamine monomer I is selected from 3, 5-diaminobenzoic acid, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 3' -diaminobenzidine, benzidine disulfonic acid, 3' -dihydroxybenzidine, 3-hydroxybenzidine, 3' -diamino-4, 4' -biphenyldiol, 5' - (3-aminophenyl) - [1,1':3', 1' -terphenyl ] -3,3' -diamine, 2, 3-diaminophenol, 2, 4-diaminophenol, 2, 5-diaminophenol, 2, 6-diaminophenol, 3, 5-diaminophenol, 3, 4-diaminobenzoic acid, 2, 3' -diamino-4-diphenyl-sulfonic acid, 3' -diamino-phenol, 3' -diamino-3 ' -diphenyl-sulfonic acid, 3' -diamino-3 ' -diphenyl-3 ' -biphenyl-3, 3' -diol, 3' -diamine disulfonic acid, 3' -bis (3, 4-hydroxy-phenyl) benzene, 3' -bis (3, 3' -diamino-phenol), 3' -bis (3 ' -amino-4-hydroxyphenyl) hexafluoropropane, 2, 3-diaminobenzoic acid, 2, 4-diaminobenzoic acid, 2, 5-diaminobenzoic acid, 2, 6-diaminobenzoic acid, 2,3, 5-triaminebenzoic acid, 4-methoxy-m-phenylenediamine, 1, 2-diamino-3-methoxybenzene, 2' -diaminobenzidine, 5' -oxybis (2-aminophenol), 3, 6-dimethoxybenzene-1, 2-diamine, 2-methoxy-p-phenylenediamine, 2,4,4' -triaminodiphenyl ether, 3, 4-diaminobenzenethiol, 4, 4-diaminodiphenyl sulfide, 22 ' -diaminodiphenyl sulfide, 3', 4-diaminobenzenesulfilide, 4,4' -diaminobenzenesulfilide, 2, 5-diaminobenzoic acid, 2,3, 5-triaminebenzoic acid, 4-methoxym-phenylenediamine, 2, 4' -diaminobenzenesulfilide, 3, 4-diaminobenzenehydrazide, 3, 5-diaminobenzenehydrazide, 3, 4-diaminobenzonitrile, (3, 4-diaminophenyl) methanol, 4 '-diamino- [1,1' -biphenyl ] -3-carbonitrile, 4 '-diamino- [1,1' -biphenyl ] -3,3 '-dicarbonitrile, 4' -diamino-3, 3',5,5' -tetrabromobiphenyl, 3 '-dichlorobenzidine, 2, 3-diaminofluorobenzene, 2, 3-difluoro-6-nitroaniline, 1, 2-diamino-3, 5-difluorobenzene, 4-methyl-5-bromoo-phenylenediamine, 4-chloro-1, 2-phenylenediamine, 4-chloro-5-bromoo-phenylenediamine, 3' -diaminobenzonitrile, 3,4 '-diaminobenzonitrile, 3' -diaminobenzonitrile, 3 '-tetrabromobiphenyl, 4, 3' -diaminobenzidine, 3, 5-difluorobenzene, 4-methyl-5-bromoo-diamine, 4-chloro-1, 2-phenylenediamine, 2-diaminobenzonitrile, and mixtures thereof, 4, 5-dichloro-1, 2-phenylenediamine, 5-chloro-m-phenylenediamine, 5-bromo-1, 3-phenylenediamine, 5-bromobenzene-1, 2, 3-triamine, 2,4, 6-tribromoaniline, 3-bromo-1, 2-diaminobenzene, 2, 5-dibromop-phenylenediamine, 4-bromo-1, 3-phenylenediamine, 2, 6-dibromo-1, 4-phenylenediamine, 2-bromo-1, 4-diaminobenzene, 2, 5-diaminobromobenzene, 3, 6-dibromo-1, 2-phenylenediamine, 2, 3-dibromoaniline, 2, 5-dibromoaniline, 3, 6-dibromo-1, 2-phenylenediamine, 2, 3-diaminofluorobenzene, 1, 3-diamino-4-fluorobenzene, 3-fluoro-1, 2-phenylenediamine, 2-fluoro-1, 4-phenylenediamine, 2, 4-diaminofluorobenzene, 4-chloro-1, 3-phenylenediamine, 2, 5-di-chloro-1, 4-phenylenediamine, 4-chloro-1, 2-phenylenediamine, 4, 5-dichloro-1, 2-phenylenediamine, 2-chloro-5-methyl-1, 4-phenylenediamine, 5-chloro-3-methyl-1, 2-phenylenediamine, and 3-chloro-o-phenylenediamine.

Specifically, the diamine monomer II is selected from 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane, aminopropyl double-terminated polydimethylsiloxane, 3, 5-diamino-1, 2, 4-triazole, diaminopyridine, 2- (4-aminophenyl) -5-aminobenzimidazole, 1-hydro-indazole-4, 7-diamine, 7-nitro-1H-indazole-4-amine, 2 '-diamino-4, 4' -bithiazole, 3, 6-diaminocarbazole, 2- (3, 6-diamino-9H-carbazol-9-yl) methyl acetate, 2, 5-diaminobenzothiazole and 2, 6-benzothiazolediamine, (6-amino-4-methylbenzo [ D ] thiazol-2-yl) carbamic acid tert-butyl ester, 4-methoxy-1, 3-benzothiazol-2, 6-diamine, benzomelamine, 2, 4-diamino-6- (2-fluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-chlorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- [4- (trifluoromethyl) phenyl ] -1,3, 5-triazine, 2, 4-diamino-6- (3-fluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- [3- (trifluoromethyl) phenyl ] -1,3, 5-triazine, 2, 4-diamino-6- (4-methylphenyl) -1,3, 5-triazine, 2, 4-diamino-6- (3, 5-difluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-bromophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-methoxyphenyl) -1,3, 5-triazine, 2, 3-diaminophenol oxazine, methylguanamine, 2, 4-diamino-6- [2- (2-methyl-1-imidazolyl) ethyl ] -1,3, 5-thiazine, 4, 6-diaminopyrimidine, 4, 6-diaminopyrimidine-5-carbonitrile, 2-benzylthio-4, 6-diaminopyrimidine, 2- (ethylthio) -4, 6-diaminopyrimidine, 2-methyl-4, 6-pyrimidinediamine, and 4- (dimethylphosphoxy) aniline.

Specifically, the diamine monomer III is at least one selected from the group consisting of 4,4' -diaminodiphenyl ether, 1, 3-bis (4' -aminophenoxy) benzene, m-phenylenediamine, p-phenylenediamine, biphenyldiamine, 4' -diaminobenzophenone, 4' -diaminodiphenylmethane, 4' -diaminodiphenylsulfone, and 2, 2-bis (4-aminophenyl) hexafluoropropane.

In fact, in the preparation method (a) and the preparation method (b), any dianhydride available in the examples of the present invention may be used as long as it is commercially available, and soluble in the polar organic solvent provided in the examples of the present invention. Specifically, the dianhydride is selected from pyromellitic dianhydride, maleic anhydride, 3,3',4,4' -biphenyltetracarboxylic dianhydride, 2,3,3',4' -diphenyl ether tetracarboxylic dianhydride, 4,4' -oxydiphthalic anhydride, 4,4' - (hexafluoroisopropylidene) diphthalic anhydride, 3,3',4,4' -benzophenone tetracarboxylic dianhydride, 3,3,4, 4-diphenylsulfone tetracarboxylic dianhydride, 4,4' -terephthaloyl diphthalic anhydride, hexafluoro dianhydride, 1, 2-ethylenebis [1, 3-dihydro-1, 3-dioxoisobenzofuran-5-carboxylate ], bisphenol A dianhydride, glycerol bis (anhydrotrimellitate) acetate, 2,3,3',4' -biphenyltetracarboxylic dianhydride, bisphenol A dianhydride, and mixtures thereof, At least one of p-phenylene-bistrimellitic dianhydride, 9-bis (3, 4-dicarboxyphenyl) fluorene dianhydride, and 4,4' - (acetylene-1, 2-diyl) diphthalic anhydride.

Specifically, the polar organic solvent is at least one selected from the group consisting of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide, tetrahydrofuran, m-cresol, γ -butyrolactone, tetramethylurea, dimethyl sulfoxide, hexamethylphosphoric triamide, and chloroform. In fact, the amount of the polar organic solvent used in the embodiment of the present invention may be changed as needed, and it is only necessary to completely dissolve the diamine and the dianhydride.

In the production method (i) and the production method (ii), the diamine and the dianhydride used in the step S11 and the step S21 are used in approximately equimolar amounts, but the molar ratio of the diamine to the dianhydride is (0.9 to 1.1: 1), and may be, for example, 0.9:1, 0.95:1, 1: 1. 1.05:1 or 1.1: 1.

in addition, in the embodiment of the present invention, in order to obtain polyimide with higher degree of polymerization, the diamine and the dianhydride used in the steps S11 and S21 are pretreated to remove impurities before use, specifically: and (2) processing the diamine in a vacuum oven at 60 ℃ for 2-3 h, and processing the dianhydride in a vacuum oven at 160 ℃ for 4-6 h.

It is to be noted that in the first production method (i) and the second production method (ii), the steps S11 and S21 are preferably performed by dissolving a predetermined amount of the diamine in the polar organic solvent, and adding a predetermined amount of the dianhydride while stirring to synthesize the first polyamic acid solution, wherein the dianhydride is added in portions, preferably in two portions, with an interval of 10 to 30 min.

In other embodiments, other methods may be used, such as: the dianhydride is dissolved in the polar organic solvent, and the diamine is added while stirring to react, thereby obtaining a polyamic acid solution. The following methods may also be employed: the diamine and the dianhydride are alternately charged into the polar organic solvent and reacted to obtain a polyamic acid solution.

The conditions of the steps S11 and S21 are not particularly limited, and are preferably performed at 10 to 50 ℃ under an inert atmosphere, more preferably at room temperature under a nitrogen atmosphere, in order to reduce the cost and obtain a polyamic acid solution having a higher polymerization degree.

Specifically, in the production method (one) and the production method (two), the graft compound may be represented by the general formula

It is shown that, among others,

represents a reactive group which reacts with the active graft structure of the diamine monomer I, the reactive group being selected from at least one of a hydroxyl group, a carboxyl group, an amino group and an epoxy group;

represents a linking group, which may or may not be a linking group, including but not limited to a benzene ring, an alkane chain, and the like;

represents a structure having a chemical interaction with copper, the structure having a chemical interaction with copper being selected from at least one of nitrogen heterocycles, siloxanes, thioethers, and phosphate esters.

Specifically, in the preparation method (one), in order to remove impurities and obtain a higher second polyamic acid solution, the step S12 further includes adding acetonitrile to the mixed system after the grafting reaction to wash out the polyamic acid solid grafted with the structure chemically interacting with copper, and drying and then re-dissolving the polyamic acid solid grafted with the structure chemically interacting with copper in the polar organic solvent to obtain the second polyamic acid solution.

In practice, the conversion of polyamic acid to polyimide is a dehydrocyclization process involving intramolecular dehydration of polyamic acid to produce a cyclic polyimide. The imidization reaction is carried out by two modes of thermal imidization and chemical imidization.

The thermal imidization process is preferably accomplished by a multi-step programmed temperature rise and maintaining at different temperatures for a certain time, and may be performed by a continuous or step temperature rise. The thermal imidization process may be performed in air, but since the vacuum state can sufficiently discharge the generated small molecular water and solvent, and the inert atmosphere can effectively reduce the thermal oxidation side reaction, it is preferable to select the thermal imidization in the vacuum state or the inert atmosphere.

The chemical imidization method requires the use of an imidizing agent selected from at least one of acetic anhydride, propionic anhydride, succinic anhydride, phthalic anhydride, and benzoic anhydride. Meanwhile, in the chemical imidization reaction, aliphatic, aromatic or heterocyclic tertiary amines such as pyridine, picoline, quinoline, isoquinoline, trimethylamine and triethylamine can be used as an imidization accelerator, so that the imidization reaction proceeds efficiently at a low temperature.

The equivalent of the imidizing agent used is not less than the equivalent of the amide bond of the polyamic acid to be chemically imidized, and is preferably 1.1 to 5 times, more preferably 1.5 to 4 times the equivalent of the amide bond. By using the imidizing agent in a slight excess amount with respect to the amide bond in this manner, the imidization reaction can be efficiently performed even at a relatively low temperature.

Specifically, before the chemical imidization is performed, it is preferable to dilute the polyamic acid solution by adding a polar organic solvent so that the chemical imidization is more efficiently performed.

In a preferred embodiment, the preparation method (i) is to imidize the second polyamic acid solution into polyimide by using a thermal imidization method, which is convenient to operate. The specific process of the step S13 is as follows: and heating the second polyimide solution in a step heating mode under the nitrogen atmosphere, and cooling to room temperature to obtain the polyimide with high bonding strength. In the step heating, each temperature step is 50-100 ℃, the holding time is 30-120 min, the heating rate is 1-10 ℃/min, the final highest temperature of heating is 300-400 ℃, and the heating process is not less than 2 h.

It is worth mentioning that, in order to improve the efficiency of thermal imidization, the second polyamic acid solution is placed in a flat mold for soft baking before the thermal imidization process is performed, and part of the polar organic solvent is removed. The second polyamic acid solution is preferably placed on a flat mold by spin coating or blade coating.

In a preferred embodiment, the second preparation method (i) is to use a chemical imidization method to imidize the first polyamic acid solution into a first polyimide solution, so as to improve the solubility of the cured polyimide for pendant group modification. Specifically, in view of the overall cost and the ease of removal after the reaction, in a preferred embodiment of the present invention, acetic anhydride is a preferred imidizing agent, and triethylamine is selected as an imidization accelerator so that the imidization reaction can be efficiently performed at a low temperature.

Specifically, the polar organic solvent is preferably added to dilute the first polyamic acid solution before chemical imidization is performed, so that imidization can be more efficiently performed.

In the embodiment of the present invention, the step S22 is not particularly limited, and is preferably performed at room temperature under a nitrogen protection.

In the second preparation method, the side chain of the first polyimide in the first polyimide solution obtained in the step S22 does not contain a structure that chemically interacts with copper, and a grafting reaction is required to obtain a polyimide with high adhesive strength. Before the grafting reaction is performed, step S23 needs to be performed to obtain a polyimide pre-solid of high purity.

Specifically, the precipitation of the polyimide precursory from the first polyimide solution in the step S23 may be performed by any method, and a method of adding a poor solvent for polyimide to precipitate polyimide and form a solid is convenient and preferable. When the polyimide is precipitated by adding a poor solvent, any poor solvent capable of precipitating polyimide can be used as the poor solvent.

Specifically, the poor solvent is selected from any one of water, methanol and ethanol.

In the case of using a poor solvent to precipitate polyimide, the amount of the poor solvent to be used needs to be sufficient to precipitate polyimide, and is determined in consideration of the structure of polyimide, the solvent of the polyimide solution, the solution concentration of polyimide, and the like, and is usually 0.5 times or more the weight of the polyimide solution.

In the specific operation of the invention, after the poor solvent is added to precipitate the polyimide pre-solid, a system containing the polyimide pre-solid is subjected to suction filtration to collect the solid phase, and the solid phase is dried in a vacuum oven at 50 ℃ for 6 hours to obtain the high-purity polyimide pre-solid.

Specifically, after obtaining the high-purity polyimide pre-solid obtained in the step S23, the steps S24 and S25 are required to be performed to obtain a polyimide having a structure having a chemical interaction with copper in a side chain.

Specifically, in the step S24, the dehydrating agent may be specifically selected from at least one of N, N' -dicyclohexylcarbodiimide, diisopropylcarbodiimide, phosphorus pentachloride, phosphorus oxychloride, and thionyl chloride.

Specifically, in the step S25, there are various methods for precipitating a polyimide solid from the third polyimide solution to obtain a polyimide with high adhesive strength, in a preferred embodiment of the present invention, water or methanol is preferably added to the third polyimide solution to precipitate a polyimide, and after precipitating the polyimide solid, in order to remove the dehydrating agent, the polar organic solvent and the graft compound to obtain a polyimide with higher purity, the obtained polyimide solid is subjected to suction filtration and drying, and the drying condition is preferably oven drying at 50 ℃ for 6 hours under vacuum condition.

According to the preparation method of the polyimide with high adhesive strength, provided by the embodiment of the invention, through molecular chain structure design, a structure which has chemical interaction with copper is designed on a side chain of a polyimide molecule, and the structure which has chemical interaction with copper is selected from at least one of nitrogen heterocyclic rings, siloxane, thioether and phosphate ester, so that the adhesive strength between the polyimide and a smooth copper surface can be improved.

In addition, the structure with chemical interaction with copper is designed in the side chain of the polyimide molecule, so that the adhesive strength can be improved under the condition of not influencing the main chain structure of the polyimide and the good main body performances of heat, mechanics, electricity and the like, meanwhile, the structure and the grafting regulation flexibility of the side chain are high, the structural design of the polyimide molecule is more flexible, and other performances can be improved in a synergistic manner while the adhesive strength is improved. The preparation method of the polyimide with high bonding strength provided by the embodiment of the invention can flexibly select the structure of the side chain and has high selectivity.

The embodiment of the invention also provides application of the polyimide with high bonding strength in a wafer-level chip packaging rewiring structure, which comprises the following steps: the polyimide with high adhesive strength is coated on a copper wire with a smooth surface to form a film.

Specifically, in step S13, the second amic acid solution is uniformly spread on a copper wire with a smooth surface by spin coating or blade coating, and imidized after soft baking to obtain a polyimide copper-clad sample; or dissolving the polyimide with high adhesive strength obtained in the step S25 in a polar organic solvent to obtain a polyimide solution, uniformly spreading the polyimide solution on a copper wire with a smooth surface in a spin coating or blade coating mode, and curing with nitrogen after soft baking to obtain the polyimide copper-clad sample.

After a polyimide copper clad sample is obtained, a peeling force test is carried out, and the obtained peeling strength is the bonding strength between the polyimide and the copper circuit with a smooth surface.

Specifically, in the examples of the present invention, the method of the peel force test is as follows: the adhesion between the polyimide and the copper wiring having a smooth surface was tested by a folding resistance tester, and the adhesion was characterized by the change in peel strength during peeling of the polyimide and the copper wiring having a smooth surface in a 90 ° peel test. According to the IPC-TM-650 standard, before testing, a sample is cut into a test strip with the width of 3mm and the length of not less than 100mm, then the test strip is fixed on a peeling test fixture, a 90-degree peeling test is carried out, the peeling speed is 50mm/min, the change of the peeling force in the peeling process is recorded, and finally the average value of three measured values is calculated to represent the peeling strength, so that the adhesion strength between the polyimide and the copper wire with a smooth surface is obtained, and the unit is N/3 mm.

In order to further illustrate the present invention, the following examples are given to describe the polyimide with high adhesive strength and the preparation method and application thereof in detail, but they should not be construed as limiting the scope of the present invention.

Example 1

S11 Synthesis of Polyamic acid

2- (4-aminophenyl) -5-aminobenzimidazole and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane are placed in a vacuum oven at 60 ℃ for treatment for 3h, pyromellitic dianhydride is placed in a vacuum oven at 160 ℃ for treatment for 4h, and impurities are removed.

1.6019g of 2- (4-aminophenyl) -5-aminobenzimidazole and 1.1212g of 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane were dissolved in 28.1089g N, N-dimethylacetamide at room temperature, and 2.2373g of pyromellitic dianhydride was added under stirring in two portions under a nitrogen atmosphere and stirred for 24 hours to synthesize a first polyamic acid solution.

S12 graft polyamic acid

Adding 4-epoxypropane carbazole with the same molar weight of hydroxyl into the first polyamic acid solution to perform grafting reaction, adding acetonitrile after the reaction is finished to wash out polyamic acid solid grafted with a structure having chemical interaction with copper, drying the polyamic acid solid grafted with the structure having chemical interaction with copper, and dissolving the polyamic acid solid in N, N-dimethylacetamide again to obtain a second polyamic acid solution.

S13 imidization

Uniformly spreading the second polyamic acid solution on a copper wire with a smooth surface by a spin coating mode, wherein the rotating speed is 1000rad/s, the time is 30s, soft-baking the copper wire on a hot plate at the temperature of 80 ℃ for 10min, and removing part of the organic solvent. The roughness of the copper circuit with the smooth surface is less than 500 nm.

Then, under the nitrogen atmosphere, heating to 100 ℃ at the speed of 5 ℃/min, and keeping for 1 h; heating from 100 deg.C to 200 deg.C at a speed of 5 deg.C/min, and maintaining for 1 h; heating from 200 ℃ to 300 ℃ at the speed of 5 ℃/min, and keeping for 1 h; heating to 350 ℃ from 300 ℃ at the speed of 5 ℃/min, and keeping for 1 h; and cooling to room temperature after the reaction is finished, obtaining the polyimide with high bonding strength on the copper circuit with smooth surface, and preparing to obtain the polyimide copper-clad sample.

Example 2

Example 2 is different from example 1 in that: the diamine monomers used in this example were in a molar ratio of 1: 1 of 2- (4-aminophenyl) -5-aminobenzimidazole and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 1, and thus are not described again.

Example 3

Example 3 is different from example 1 in that: the diamine monomers used in this example were in a molar ratio of 3: 7 of 2- (4-aminophenyl) -5-aminobenzimidazole and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 1, and thus are not described again.

Example 4

Example 4 is different from example 1 in that: the diamine monomers used in this example were in a molar ratio of 1: 1 of 4,4' -diaminodiphenyl ether and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 1, and thus are not described again.

Example 5

Example 5 differs from example 1 in that: the diamine monomers used in this example were in a molar ratio of 3: 7 of 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 1, and thus are not described again.

Example 6

Example 6 differs from example 1 in that: the diamine monomers used in this example were in a molar ratio of 1: 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, and the rest of the materials and the preparation process in this example are completely the same as those in example 1, and thus are not repeated.

Example 7

Example 7 is different from example 1 in that: the diamine monomers used in this example were in a molar ratio of 1: 1: 4,4' -diaminodiphenyl ether and 2- (4-aminophenyl) -5-aminobenzimidazole of 1 and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, and the rest of the materials and the preparation process in this example are completely the same as those in example 1, and thus the description thereof is omitted.

Example 8

S21, synthesis of polyamic acid: 3, 5-diaminobenzoic acid and 4,4' -diaminodiphenyl ether are placed in a vacuum oven at 60 ℃ for treatment for 3 hours, 2,3,3',4' -diphenyl ether tetracarboxylic dianhydride is placed in a vacuum oven at 160 ℃ for treatment for 6 hours, and impurities are removed.

A first polyamic acid solution was synthesized by adding 0.5g of mixed diamine of 3, 5-diaminobenzoic acid and 0.381g of 4,4' -diaminodiphenyl ether in 13.781g of N-methylpyrrolidone in a flask at room temperature, and then adding 1.55g of 2,3,3',4' -diphenylether tetracarboxylic dianhydride under nitrogen while stirring twice and stirring for 6 hours.

S22, imidization: to the first polyamic acid solution were added 13.77g of N-methylpyrrolidone, and after stirring for 5min to sufficiently dilute the solution, 1.5606g of acetic anhydride and 1.737g of triethylamine were added, and stirring was performed for 12 hours under a nitrogen atmosphere, to obtain a first polyimide solution.

S23, adding 2L of deionized water into the first polyimide solution, separating out a first polyimide solid, carrying out suction filtration on a system containing the polyimide pre-solid, collecting the solid, and drying in a vacuum oven at 50 ℃ for 6 hours to obtain the high-purity polyimide pre-solid.

S24, graft polyimide: dissolving 2.2g of polyimide pre-solid in 41.8g of N-methylpyrrolidone, and stirring for 4 hours to obtain a second polyimide solution;

adding N, N' -dicyclohexylcarbodiimide into the second polyimide solution, stirring for 2 hours under the conditions of nitrogen atmosphere and ice-water bath, then adding 0.205g of 3-amino-1, 2, 4-triazole into the solution, and stirring for 6 hours to obtain a third polyimide solution;

s25, dropping the third polyimide solution into 2L of deionized water, filtering, and drying the obtained product in a vacuum oven at 50 ℃ for 6h to obtain the polyimide with high adhesive strength.

And (4) dissolving the polyimide with high bonding strength obtained in the step (S25) in N-methyl pyrrolidone to obtain a polyimide solution, uniformly spreading the polyimide solution on a copper wire with a smooth surface in a spin coating or blade coating mode, and curing with nitrogen after soft baking to obtain a polyimide copper-clad sample. Wherein the roughness of the copper circuit with smooth surface is less than 400 nm.

Example 9

Example 9 differs from example 8 in that: the diamine monomers used in this example were in a molar ratio of 1: 1, 4-diaminobenzoic acid and 4,4' -diaminodiphenyl ether, the grafting compound used in step S24 is 4-aminotriazole in the same molar amount as the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 10

Example 10 is different from example 8 in that: the diamine monomers used in this example were in a molar ratio of 1: 1 of 2, 4-diaminobenzoic acid and 4,4' -diaminodiphenyl ether, the grafting compound used in step S24 being 2-mercaptopyrimidine in the same molar amount as the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 11

Example 11 differs from example 8 in that: the diamine monomers used in this example were in a molar ratio of 1: 1,2, 4-diaminobenzoic acid and 2- (4-aminophenyl) -5-aminobenzimidazole, the grafting compound used in step S24 being 2-amino-3-mercaptopyridine in the same molar amount as the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 12

Example 12 compares to example 8 with the following differences: the diamine monomers used in this example were in a molar ratio of 1: 1, 4-diaminobenzoic acid and 4,4' -diaminodiphenyl ether, the grafting compound used in step S24 being 3-pyridinesulfonic acid in the same molar amount as the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 13

Example 13 compares to example 8 with the following differences: the diamine monomers used in this example were in a molar ratio of 3: 7 of 2, 3-diaminophenol and m-phenylenediamine, the grafting compound used in step S24 is 4-epoxypropyleneoxycarbazole in the same molar amount as the hydroxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 14

Example 14 compares to example 8 with the following differences: the diamine monomers used in this example were in a molar ratio of 6: 4, 3-diaminobenzoic acid and 4,4' -diaminobenzophenone, the grafting compound used in step S24 being 1, 4-butanedithiol in the same molar amount as the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 15

Example 15 differs from example 8 in that: the diamine monomers used in this example were in a molar ratio of 1: 1,2, 3-diaminobenzoic acid and 2- (4-aminophenyl) -5-aminobenzimidazole, the grafting compound used in step S24 being dimercaprol in an equimolar amount to the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 16

Example 16 differs from example 8 in that: the diamine monomers used in this example were in a molar ratio of 1: 1,2, 3-diaminobenzoic acid and 2- (4-aminophenyl) -5-aminobenzimidazole, the grafting compound used in step S24 being (4-hydroxyphenyl) phosphonic acid in an equimolar amount to the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 17

Example 17 compares to example 8 with the difference that: the diamine monomers used in this example were in a molar ratio of 1: 1,2, 3-diaminobenzoic acid and 2- (4-aminophenyl) -5-aminobenzimidazole, the grafting compound used in step S24 being (4-aminophenyl) phosphonic acid in an equimolar amount to the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 18

Example 18 is different from example 8 in that: the diamine monomers used in this example were in a molar ratio of 1: 1,2, 3-diaminobenzoic acid and 2- (4-aminophenyl) -5-aminobenzimidazole, the grafting compound used in step S24 being 1, 3-bis (3-hydroxypropyl) -1,1,3, 3-tetramethyldisiloxane in the same molar amount as the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Example 19

Example 19 compares to example 8 with the following differences: the diamine monomers used in this example were in a molar ratio of 1: 1: 1 of 2, 3-diaminobenzoic acid and 2- (4-aminophenyl) -5-aminobenzimidazole and 4,4' -diaminodiphenyl ether, the grafting compound used in step S24 being 4-aminotriazole in the same molar amount as the carboxyl group. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 8, and thus are not described again.

Comparative example 1

Comparative example 1 differs from example 1 in that: the diamine monomer used in this example was 4,4' -diaminodiphenyl ether and step S12 was not required. The rest of the materials and the preparation process in this embodiment are completely the same as those in embodiment 1, and thus are not described again.

The polyimide copper clad samples prepared in the above examples 1 to 19 and comparative example 1 were cut into test specimens having a width of 3mm and a length of not less than 100mm before the test according to the IPC-T M-650 standard, and then fixed on a peel test jig to perform a 90 ° peel test at a peel speed of 50mm/min, and the change in peel force during the peel was recorded, and finally the average value of the three measurements was calculated as the peel strength, i.e., the adhesive strength between the polyimide and the copper wiring having a smooth surface in the unit of N/3 mm. The experimental data are shown in table 1.

TABLE 1

Examples of the embodiments	Adhesive strength	Examples of the embodiments	Adhesive strength
				Example 1	1.0295	Example 11	1.1941
Example 2	1.1143	Example 12	1.0059
				Example 3	1.2674	Example 13	1.0564
Example 4	0.9292	Example 14	1.1936
				Example 5	1.3367	Example 15	1.2652
Example 6	1.1853	Example 16	1.1783
				Example 7	0.9858	Example 17	1.1896
Example 8	1.0965	Example 18	1.1377
				Example 9	1.1374	Example 19	1.0191
Example 10	0.9783	Comparative example 1	0.5950

As can be seen from table 1, the adhesive strength between the polyimide and the copper wire having a smooth surface was improved by at least 55% in examples 1 to 19, as compared to comparative example 1. Therefore, the polyimide with high bonding strength is applied to the wafer-level chip packaging rewiring structure, the high bonding strength is formed between the polyimide and the copper circuit surface with the smooth surface, the interface failure phenomenon is prevented, and the polyimide can be used for high-frequency transmission.

The foregoing is directed to embodiments of the present application and it is noted that numerous modifications and adaptations may be made by those skilled in the art without departing from the principles of the present application and are intended to be within the scope of the present application.

Claims

1. A polyimide having high adhesive strength, characterized by having a repeating structural unit represented by the general formula (1) containing a structure having a chemical interaction with copper;

in the general formula (1) described above,

represents a dianhydride functional group and a dianhydride functional group,

represents a diamine functional group

2. A preparation method of polyimide with high bonding strength is characterized by comprising the following steps:

3. A method for producing a high adhesion strength polyimide as claimed in claim 2, wherein said diamine further comprises a diamine monomer II and/or a diamine monomer III, said diamine monomer II being a diamine monomer having a structure that chemically interacts with copper; the diamine monomer III is a diamine monomer free of a target structure including the structure having a chemical interaction with copper and the living graft structure.

4. A method for producing a polyimide with high adhesive strength as described in claim 3, wherein said diamine monomer I is selected from the group consisting of 3, 5-diaminobenzoic acid, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 3' -diaminobenzidine, benzidine disulfonic acid, 3' -dihydroxybenzidine, 3-hydroxybenzidine, 3' -diamino-4, 4' -biphenyldiol, 5' - (3-aminophenyl) - [1,1':3',1 "-terphenyl ] -3,3" -diamine, 2, 3-diaminophenol, 2, 4-diaminophenol, 2, 5-diaminophenol, 2, 6-diaminophenol, 3, 5-diaminophenol, and mixtures thereof, 3, 4-diaminophenol, 3, 4-diaminobenzoic acid, 2, 3-diaminobenzoic acid, 2, 4-diaminobenzoic acid, 2, 5-diaminobenzoic acid, 2, 6-diaminobenzoic acid, 2,3, 5-triaminobenzoic acid, 4-methoxy-m-phenylenediamine, 1, 2-diamino-3-methoxybenzene, 2' -diaminobenzidine, 5' -oxybis (2-aminophenol), 3, 6-dimethoxybenzene-1, 2-diamine, 2-methoxy-p-phenylenediamine, 2,4,4' -triaminodiphenyl ether, 3, 4-diaminobenzenethiol, 4, 4-diaminodiphenyl sulfide, 22 ' -diaminodiphenyl sulfide, 3', 4-diaminobenzeneanilide, 2, 3' -diaminobenzenesulfenyl, 4-diaminobenzenesulfenyl, 2, 4-diaminodiphenyl oxide, 2, 4-diaminobenzenesulfenyl, 2, 4-diaminodiphenyl oxide, 2, 5' -diaminodiphenyl sulfide, 2, 5-diaminobenzenesulfenyl, 2, 4-diaminobenzeneamide, 2,3, 4-diaminobenzenesulfenyl, 4, and benzene, 4,4 '-diaminobenzanilide, 3, 4-diaminobenzenehydrazide, 3, 5-diaminobenzenehydrazide, 3, 4-diaminobenzonitrile, (3, 4-diaminophenyl) methanol, 4' -diamino- [1,1 '-biphenyl ] -3-carbonitrile, 4' -diamino- [1,1 '-biphenyl ] -3,3' -dicarbonitrile, 4 '-diamino-3, 3',5,5 '-tetrabromobiphenyl, 3' -dichlorobenzidine, 2, 3-diaminofluorobenzene, 2, 3-difluoro-6-nitroaniline, 1, 2-diamino-3, 5-difluorobenzene, 4-methyl-5-bromoo-phenylenediamine, N-phenylthiopropionic acid, N-carbonyl-2, N-phenylthiopropionic acid, N-carbonyl-4, 4-methyl-5-bromoo-phenylenediamine, N-phenylthionylamine, N-2-carbonyl-2, 4-amino-2-carbonyl-phenylthionylamine, 4-methyl-5-bromoo-phenylthionylamine, N-2-carboxylic acid, N-2-carbonyl, N-2-amide, N-2-carbonyl-amide, 4-2-one, and its derivatives, 4-methyl-carboxylic acid, 4-amide, 4-chloro-1, 2-phenylenediamine, 4, 5-dichloro-1, 2-phenylenediamine, 5-chloro-m-phenylenediamine, 5-bromo-1, 3-phenylenediamine, 5-bromobenzene-1, 2, 3-triamine, 2,4, 6-tribromoaniline, 3-bromo-1, 2-diaminobenzene, 2, 5-dibromop-phenylenediamine, 4-bromo-1, 3-phenylenediamine, 2, 6-dibromo-1, 4-phenylenediamine, 2-bromo-1, 4-diaminobenzene, 2, 5-diaminobromobenzene, 3, 6-dibromo-1, 2-phenylenediamine, 2, 3-dibromoaniline, 2, 5-dibromoaniline, 3, 6-dibromo-1, at least one of 2-phenylenediamine, 2, 3-diaminofluorobenzene, 1, 3-diamino-4-fluorobenzene, 3-fluoro-1, 2-phenylenediamine, 2-fluoro-1, 4-phenylenediamine, 2, 4-diaminofluorobenzene, 4-chloro-1, 3-phenylenediamine, 2, 5-di-chloro-1, 4-phenylenediamine, 4-chloro-1, 2-phenylenediamine, 4, 5-dichloro-1, 2-phenylenediamine, 2-chloro-5-methyl-1, 4-phenylenediamine, 5-chloro-3-methyl-1, 2-phenylenediamine, and 3-chloro-o-phenylenediamine;

the diamine monomer II is selected from 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane, aminopropyl double-terminated polydimethylsiloxane, 3, 5-diamino-1, 2, 4-triazole, diaminopyridine, 2- (4-aminophenyl) -5-aminobenzimidazole, 1H-indazole-4, 7-diamine, 7-nitro-1H-indazole-4-amine, 2 '-diamino-4, 4' -bithiazole, 3, 6-diaminocarbazole, 2- (3, 6-diamino-9H-carbazole-9-yl) methyl acetate, 2, 5-diaminobenzothiazole, 2, 6-benzothiazole diamine, 2, 6-amino-1H-carbazole-9-yl, (6-amino-4-methylbenzo [ D ] thiazol-2-yl) carbamic acid tert-butyl ester, 4-methoxy-1, 3-benzothiazole-2, 6-diamine, benzoguanamine, 2, 4-diamino-6- (2-fluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-chlorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- [4- (trifluoromethyl) phenyl ] -1,3, 5-triazine, 2, 4-diamino-6- (3-fluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- [3- (trifluoromethyl) phenyl ] -1,3, 5-triazine, 2, 4-diamino-6- (4-methylphenyl) -1,3, 5-triazine, 2, 4-diamino-6- (3, 5-difluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-bromophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-methoxyphenyl) -1,3, 5-triazine, 2, 3-diaminophenolazine, methylguanamine, 2, 4-diamino-6- [2- (2-methyl-1-imidazolyl) ethyl ] -1,3, 5-thiazine, 4, 6-diaminopyrimidine, 4, at least one of 6-diaminopyrimidine-5-carbonitrile, 2-benzylthio-4, 6-diaminopyrimidine, 2- (ethylthio) -4, 6-diaminopyrimidine, 2-methyl-4, 6-pyrimidinediamine, and 4- (dimethylphosphite) aniline;

the diamine monomer III is at least one selected from 4,4' -diaminodiphenyl ether, 1, 3-bis (4' -aminophenoxy) benzene, m-phenylenediamine, p-phenylenediamine, diphenylenediamine, 4' -diaminobenzophenone, 4' -diaminodiphenylmethane, 4' -diaminodiphenylsulfone and 2, 2-bis (4-aminophenyl) hexafluoropropane.

5. A method for preparing polyimide with high adhesive strength according to any one of claims 2 to 4, wherein the thermal imidization is carried out by the following specific process: heating in a nitrogen atmosphere by adopting a step heating mode, and cooling to room temperature to obtain polyimide with high bonding strength; in the step heating, each temperature step is 50-100 ℃, the holding time is 30-120 min, the heating rate is 1-10 ℃/min, the final highest temperature of heating is 300-400 ℃, and the heating process is not less than 2 h.

6. A preparation method of polyimide with high bonding strength is characterized by comprising the following steps:

s21, synthesizing polyamic acid: dissolving diamine in a polar organic solvent, adding dianhydride, and synthesizing a first polyamic acid solution;

s22, imidization: adding an imidizing agent and an imidizing accelerator into the first polyamic acid solution to perform chemical imidization to obtain a first polyimide solution;

s23, precipitating a polyimide pre-solid from the first polyimide solution;

7. A method for producing a high adhesion strength polyimide as claimed in claim 6, wherein said diamine further comprises a diamine monomer II and/or a diamine monomer III, said diamine monomer II being a diamine monomer having a structure that chemically interacts with copper; the diamine monomer III is a diamine monomer free of a target structure including the structure having a chemical interaction with copper and the living graft structure.

8. A method for producing a polyimide with high adhesive strength as described in claim 7, wherein said diamine monomer I is selected from the group consisting of 3, 5-diaminobenzoic acid, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 3' -diaminobenzidine, benzidine disulfonic acid, 3' -dihydroxybenzidine, 3-hydroxybenzidine, 3' -diamino-4, 4' -biphenyldiol, 5' - (3-aminophenyl) - [1,1':3',1 "-terphenyl ] -3,3" -diamine, 2, 3-diaminophenol, 2, 4-diaminophenol, 2, 5-diaminophenol, 2, 6-diaminophenol, 3, 5-diaminophenol, and mixtures thereof, 3, 4-diaminophenol, 3, 4-diaminobenzoic acid, 2, 3-diaminobenzoic acid, 2, 4-diaminobenzoic acid, 2, 5-diaminobenzoic acid, 2, 6-diaminobenzoic acid, 2,3, 5-triaminobenzoic acid, 4-methoxy-m-phenylenediamine, 1, 2-diamino-3-methoxybenzene, 2' -diaminobenzidine, 5' -oxybis (2-aminophenol), 3, 6-dimethoxybenzene-1, 2-diamine, 2-methoxy-p-phenylenediamine, 2,4,4' -triaminodiphenyl ether, 3, 4-diaminobenzenethiol, 4, 4-diaminodiphenyl sulfide, 22 ' -diaminodiphenyl sulfide, 3', 4-diaminobenzeneanilide, 2, 3' -diaminobenzenesulfenyl, 4-diaminobenzenesulfenyl, 2, 4-diaminodiphenyl oxide, 2, 4-diaminobenzenesulfenyl, 2, 4-diaminodiphenyl oxide, 2, 5' -diaminodiphenyl sulfide, 2, 5-diaminobenzenesulfenyl, 2, 4-diaminobenzeneamide, 2,3, 4-diaminobenzenesulfenyl, 4, and benzene, 4,4 '-diaminobenzanilide, 3, 4-diaminobenzenehydrazide, 3, 5-diaminobenzenehydrazide, 3, 4-diaminobenzonitrile, (3, 4-diaminophenyl) methanol, 4' -diamino- [1,1 '-biphenyl ] -3-carbonitrile, 4' -diamino- [1,1 '-biphenyl ] -3,3' -dicarbonitrile, 4 '-diamino-3, 3',5,5 '-tetrabromobiphenyl, 3' -dichlorobenzidine, 2, 3-diaminofluorobenzene, 2, 3-difluoro-6-nitroaniline, 1, 2-diamino-3, 5-difluorobenzene, 4-methyl-5-bromoo-phenylenediamine, N-phenylthiopropionic acid, N-carbonyl-2, N-phenylthiopropionic acid, N-carbonyl-4, 4-methyl-5-bromoo-phenylenediamine, N-phenylthionylamine, N-2-carbonyl-2, 4-amino-2-carbonyl-phenylthionylamine, 4-methyl-5-bromoo-phenylthionylamine, N-2-carboxylic acid, N-2-carbonyl, N-2-amide, N-2-carbonyl-amide, 4-2-one, and its derivatives, 4-methyl-carboxylic acid, 4-amide, 4-chloro-1, 2-phenylenediamine, 4, 5-dichloro-1, 2-phenylenediamine, 5-chloro-m-phenylenediamine, 5-bromo-1, 3-phenylenediamine, 5-bromobenzene-1, 2, 3-triamine, 2,4, 6-tribromoaniline, 3-bromo-1, 2-diaminobenzene, 2, 5-dibromop-phenylenediamine, 4-bromo-1, 3-phenylenediamine, 2, 6-dibromo-1, 4-phenylenediamine, 2-bromo-1, 4-diaminobenzene, 2, 5-diaminobromobenzene, 3, 6-dibromo-1, 2-phenylenediamine, 2, 3-dibromoaniline, 2, 5-dibromoaniline, 3, 6-dibromo-1, at least one of 2-phenylenediamine, 2, 3-diaminofluorobenzene, 1, 3-diamino-4-fluorobenzene, 3-fluoro-1, 2-phenylenediamine, 2-fluoro-1, 4-phenylenediamine, 2, 4-diaminofluorobenzene, 4-chloro-1, 3-phenylenediamine, 2, 5-di-chloro-1, 4-phenylenediamine, 4-chloro-1, 2-phenylenediamine, 4, 5-dichloro-1, 2-phenylenediamine, 2-chloro-5-methyl-1, 4-phenylenediamine, 5-chloro-3-methyl-1, 2-phenylenediamine, and 3-chloro-o-phenylenediamine;

the diamine monomer II is selected from 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane, aminopropyl double-terminated polydimethylsiloxane, 3, 5-diamino-1, 2, 4-triazole, diaminopyridine, 2- (4-aminophenyl) -5-aminobenzimidazole, 1H-indazole-4, 7-diamine, 7-nitro-1H-indazole-4-amine, 2 '-diamino-4, 4' -bithiazole, 3, 6-diaminocarbazole, 2- (3, 6-diamino-9H-carbazole-9-yl) methyl acetate, 2, 5-diaminobenzothiazole, 2, 6-benzothiazole diamine, 2, 6-amino-1H-carbazole-9-yl, (6-amino-4-methylbenzo [ D ] thiazol-2-yl) carbamic acid tert-butyl ester, 4-methoxy-1, 3-benzothiazole-2, 6-diamine, benzoguanamine, 2, 4-diamino-6- (2-fluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-chlorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- [4- (trifluoromethyl) phenyl ] -1,3, 5-triazine, 2, 4-diamino-6- (3-fluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- [3- (trifluoromethyl) phenyl ] -1,3, 5-triazine, 2, 4-diamino-6- (4-methylphenyl) -1,3, 5-triazine, 2, 4-diamino-6- (3, 5-difluorophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-bromophenyl) -1,3, 5-triazine, 2, 4-diamino-6- (4-methoxyphenyl) -1,3, 5-triazine, 2, 3-diaminophenol oxazine, methylguanamine, 2, 4-diamino-6- [2- (2-methyl-1-imidazolyl) ethyl ] -1,3, 5-thiazine, 4, 6-diaminopyrimidine, 4, at least one of 6-diaminopyrimidine-5-carbonitrile, 2-benzylthio-4, 6-diaminopyrimidine, 2- (ethylthio) -4, 6-diaminopyrimidine, 2-methyl-4, 6-pyrimidinediamine, and 4- (dimethylphosphite) aniline;

9. The method for producing a polyimide with high adhesive strength according to any one of claims 6 to 8, wherein the imidizing agent is at least one selected from the group consisting of acetic anhydride, propionic anhydride, succinic anhydride, phthalic anhydride and benzoic anhydride;

the imidization accelerator is at least one selected from triethylamine, pyridine, picoline, quinoline, isoquinoline and trimethylamine;

the dehydrating agent is at least one selected from N, N' -dicyclohexylcarbodiimide, diisopropylcarbodiimide, phosphorus pentachloride, phosphorus oxychloride and thionyl chloride.

10. The use of the high adhesion polyimide according to claim 1 in a wafer level chip package rewiring structure, comprising the steps of: and coating the polyimide with high adhesive strength on a copper wire with a smooth surface to form a film.