A bottom filling adhesive based on modified amine curing agent and its preparation method and application

Abstract

The present invention provides a bottom filling glue based on a modified amine curing agent, and a preparation method and application thereof, belonging to the technical field of adhesives. The bottom filling glue based on a modified amine curing agent of the present invention comprises an epoxy resin, a filler, a silane coupling agent, an elastomer and a modified amine curing agent, wherein the modified amine curing agent is obtained by modifying the amine curing agent with aldehydes and phenolic compounds through a Mannich reaction. The present invention modifies the amine curing agent with aldehydes and phenolic compounds through a Mannich reaction, and introduces the modified amine curing agent into the formula of the bottom filling glue, which can effectively improve the interface bonding strength between the bottom filling glue and the substrate (such as Si, SiN substrate), so that it can still maintain a high bonding strength after PCT aging treatment, and is applied to chip packaging to improve the reliability of the package.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and relates to a bottom filling adhesive based on a modified amine curing agent, and a preparation method and application thereof. Background Art

[0002] Flip-chip has attracted great attention as a first-level interconnect technology due to the rapid development of integrated circuit (IC) manufacturing and the growing market for faster, lighter, smaller and cheaper electronic products. Flip-chip has many advantages over traditional packaging using wire bonding technology, such as high I / O density, short interconnects, self-alignment, better heat dissipation through the back of the chip, smaller footprint, smaller form factor, etc. A major problem with flip-chip technology is the thermo-mechanical fatigue life of the C4 solder joint. This thermo-mechanical problem mainly stems from the mismatch in the coefficient of thermal expansion (CTE) between the silicon chip (2.5ppm / ℃) and the substrate (4~10ppm / ℃ for ceramic and 18~24ppm / ℃ for organic FR4 board). Therefore, as the chip size increases, thermo-mechanical reliability becomes a critical issue.

[0003] The invention of underfill is one of the most innovative developments in the use of low-cost organic substrates in flip-chip packaging. Underfill is a liquid encapsulation material that is typically heavily filled with SiO 2 The epoxy resin is applied between the chip and the substrate after the flip chip interconnection. After curing, the hardened underfill exhibits high modulus, low CTE that matches the solder joints, and good adhesion to the chip and substrate. The thermal stress on the solder joints is redistributed between the chip, underfill, substrate, and all solder joints instead of being concentrated on the peripheral solder joints. The application of underfill can reduce the most important solder strain level to 0.10-0.25 of the unpackaged joint strain. Therefore, the use of underfill can increase the fatigue life of the solder joint by 10-100 times. In addition, it also provides environmental protection for the solder joints. Underfill has become a practical solution to expand the application of flip chip technology from ceramics to organic substrates and from high-end products to cost-sensitive products, which is the main reason why flip chips are so popular today.

[0004] When the bottom filler is used to protect the solder balls in the Flip Chip package, there are many interfaces that need to be contacted, such as: silicon chip, passivation layer, solder balls and green oil base. In addition, due to the complex use environment of the package, especially as the size of electronic products gradually decreases, the package will inevitably be used in high temperature, high pressure and high humidity environments, but most of the bottom fillers currently used are epoxy resin-based. Therefore, the bottom filler has a tendency to absorb moisture, which will cause adverse changes in adhesion and stress, and reduce the reliability of the package. Therefore, in order to improve the reliability of the package, the bonding strength between the bottom filler and various interfaces needs to be improved, and the resistance to moisture and heat, high temperature and high pressure and other properties of the bottom filler and various interfaces must also be improved.

[0005] The bottom filler needs to contact multiple interfaces when protecting the solder balls in the IC package, among which the main ones are the Si chip, passivation layer, solder balls and solder mask. Due to the complex and changeable use environment of the package, it is inevitable to be used in high temperature, high pressure and high humidity environment. In this case, water vapor will enter the package through the interface, which will not only cause the bottom filler and the substrate to delaminate, but also cause popcorn phenomenon inside at high temperature. Therefore, it is necessary to improve the bonding strength between the bottom filler and the substrate to prevent water vapor from entering the interface under high temperature and high humidity environment and improve the reliability of the package. At present, the main ways to improve the bonding strength and moisture and heat resistance can be divided into two types; the first is to add an adhesion promoter to the bottom filler formula; the second is to perform surface treatment on the corresponding substrate to improve the initial bonding strength and moisture and heat resistance.

[0006] However, when introducing an adhesion promoter into the bottom filler formula, this adhesion promoter must not only have good compatibility with the organic resin, inorganic filler and various additives in the formula, but also have certain compatibility with different types of substrates; this makes the selection of adhesion promoters very restrictive, so the commonly used adhesion promoter is a silane coupling agent. The introduction of silane coupling agents into the bottom filler system can effectively improve the moisture and heat aging resistance of the bottom filler, but it has no effect on improving the initial interface bonding strength at room temperature. In addition, improper selection of coupling agents will cause a sharp increase in the viscosity of the bottom filler, and even in the capillary bottom filler system, the bottom filler will not be injectable, making it impossible to apply it to Flip Chip packaging.

[0007] At present, the main methods for substrate surface treatment include: self-assembled monolayer (SAM), plasma treatment, UV / O 3Cleaning, ion implantation and chemical oxidation, etc. Among them, the self-assembled monolayer refers to a thermodynamically stable, orderly arranged molecular structure formed by organic functional molecules on the solid surface by chemical adsorption. Generally, the solid surface is immersed in a dilute solution containing active substances, and a monolayer film is formed by physical adsorption and chemical bonding within a certain period of time. Plasma treatment improves the surface properties of the material, such as surface wettability, roughness, surface energy, cleanliness, etc., by physical and chemical changes such as oxidation, cleaning, etching, and polymerization of the substrate surface, thereby improving the interfacial bonding strength. Wet treatment of copper surface can make copper and its alloys retain the excellent electrical and mechanical properties of the body while also having multiple properties such as high surface corrosion resistance, high wear resistance and high hardness. The above-mentioned surface treatment methods can effectively improve the initial interfacial bonding strength, but the moisture and heat resistance performance needs to be improved. In addition, these surface treatment methods are specific, and these surface treatment methods will make the packaging process more complicated and have no commercial value.

[0008] In view of this, it is urgent to research and prepare a new bottom filling glue that can still maintain a high bonding strength after PCT aging treatment, thereby improving the reliability of the package; and there is no need to improve the interface bonding strength through substrate surface treatment to avoid complicating the packaging process. Summary of the invention

[0009] In view of this, the present invention provides a bottom filling glue based on a modified amine curing agent, and a preparation method and application thereof. The present invention uses aldehydes and phenolic compounds to modify the amine curing agent through a Mannich reaction, and introduces the modified amine curing agent into the formula of the bottom filling glue, which can effectively improve the interface bonding strength between the bottom filling glue and the substrate (such as Si, SiN substrate), so that the bottom filling glue can still maintain a high bonding strength after PCT aging treatment, and is applied to chip packaging to improve the reliability of the package.

[0010] To achieve the above object, the present invention provides a bottom filling adhesive based on a modified amine curing agent, comprising an epoxy resin, a filler, a silane coupling agent, an elastomer and a modified amine curing agent.

[0011] The modified amine curing agent is obtained by modifying the amine curing agent using aldehydes and phenolic compounds through the Mannich reaction. The chemical reaction process is shown in the following formula:

[0012]

[0013] Preferably, the aldehyde in the Mannich reaction is formaldehyde, or trioxymethylene, or polyformaldehyde.

[0014] Preferably, the phenolic compounds in the Mannich reaction include monohydric phenols, dihydric phenols and trihydric phenols; the amine curing agents include aliphatic amines, alicyclic amines and aromatic amines, which are primary amines or secondary amines.

[0015] Preferably, the phenolic compound in the Mannich reaction is any one of 2-methyl-5-isopropylphenol, 2-isopropyl-5-methylphenol, 2,4-di-tert-butylphenol, 2,6-di-tert-butyl-p-phenol, 2,2-methylenebis(6-tert-butyl-p-cresol), 2,6-di-tert-butyl-4-methylphenol, p-tert-butylphenol, 4-tert-butylcatechol (TBC), and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0016] Amine curing agents include diethylenetriamine, ethylenediamine, triethylenetetramine, 1,6-hexanediamine, tetraethylenepentamine, 4-amino-α,α-4-trimethyl-cyclohexanemethylamine, 5-amino-1,3,3-trimethylcyclohexanemethylamine, bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis(2-methyl-6-ethyl)- Any one of aniline), m-phenylenediamine, m-phenylenediamine, 4,4-diaminodiphenyl sulfone, 4,4-diaminodiphenylmethane, diethyltoluenediamine, dimethylthiotoluenediamine, 3-chloro-3'-ethyl-4,4'-diaminodiphenylmethane, 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2-ethyl)aniline, 4,4'-bis-sec-butylaminodiphenylmethane, and 4,4'-methylene-bis(3-chloro-2,6-diethylaniline).

[0017] Preferably, the filler is a spherical silica filler with a particle size of 1 to 10 μm.

[0018] Preferably, the silane coupling agent contains active groups and is compatible with the epoxy resin system.

[0019] Preferably, the elastomer is any one of silicone rubber, butadiene rubber, styrene butadiene rubber and methacrylate-butadiene-styrene.

[0020] The present invention also provides a method for preparing the bottom filling glue based on the modified amine curing agent as described above, which comprises first mixing the epoxy resin, filler, silane coupling agent and elastomer, and then adding the modified amine curing agent to mix.

[0021] Preferably, the method further comprises the preparation of the modified amine curing agent, the process of which is as follows:

[0022] Firstly, the aldehyde is dissolved in the amine curing agent at 40-70°C, and then the mixture is added into the ethanol solution of the phenolic compound, followed by reflux reaction at 80-95°C for 4 hours, and finally the solvent and water are evaporated at 80-100°C.

[0023] The present invention also provides a use of the bottom filling glue based on the modified amine curing agent as described above in chip packaging.

[0024] The advantages of the present invention using the above technical solution are:

[0025] (1) The modified amine curing agent prepared by the present invention exhibits excellent interfacial bonding performance and PCT aging resistance; (2) The modified amine curing agent prepared by the present invention has excellent compatibility with the bottom filling glue system and does not produce a negative effect on the viscosity of the product, which is unmatched by other adhesion promoters; (3) During the use of the modified amine curing agent prepared by the present invention, there is no need to perform special treatment on the substrate, and the process is simple; (4) The modified amine curing agent prepared by the present invention has a clear synthesis mechanism and a simple synthesis route, is easy to industrialize and is convenient for large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the structure of a sandwich structure test specimen in an adhesive strength test of bottom filling adhesives prepared in an embodiment of the present invention and a comparative example;

[0028] Figure 2 The diagram is an interface fracture failure mode diagram of the bottom filling adhesives prepared in the embodiments of the present invention and the comparative examples after the bonding strength test. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The invention provides a bottom filling adhesive based on a modified amine curing agent, comprising epoxy resin, filler, silane coupling agent, elastomer and the modified amine curing agent.

[0031] The modified amine curing agent is obtained by modifying the amine curing agent using aldehydes and phenolic compounds through the Mannich reaction. The chemical reaction process is shown in the following formula:

[0032]

[0033] The present invention uses aldehyde compounds as intermediate media and introduces phenolic compounds into traditional amine molecular chains to obtain a modified amine curing agent. Compared with traditional amine curing agents, a large number of active hydroxyl groups and rigid phenyl groups are introduced. On the one hand, the active hydroxyl groups effectively improve the bonding performance of the bottom filling glue by forming hydrogen bonds and chemical reactions with the base material; on the other hand, the rigid phenyl groups can effectively improve the heat resistance, aging resistance and moisture resistance of the bottom filling glue.

[0034] The aldehyde in the Mannich reaction can be selected from formaldehyde and its aqueous solution, or trioxymethylene, or polyformaldehyde.

[0035] The phenolic compound can be monophenol, diphenol and triphenol, wherein the more phenolic hydroxyl groups, the better the moisture and heat aging resistance of the glue, but the phenolic hydroxyl groups generally cannot exceed three, for example: 2-methyl-5-isopropylphenol, 2-isopropyl-5-methylphenol, 2,4-di-tert-butylphenol, 2,6-di-tert-butyl-p-phenol, 2,2-methylenebis(6-tert-butyl-p-cresol), 2,6-di-tert-butyl-4-methylphenol, p-tert-butylphenol, 4-tert-butylcatechol (TBC), tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester. Monophenol and diphenol compounds are preferred to modify the amine curing agent.

[0036] Amine curing agents can be aliphatic amines, alicyclic amines and aromatic amines, and can also be primary amines and secondary amines, such as diethylenetriamine, ethylenediamine, triethylenetetramine, 1,6-hexanediamine, tetraethylenepentamine, 4-amino-α,α-4-trimethyl-cyclohexanemethylamine, 5-amino-1,3,3-trimethylcyclohexanemethylamine, bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, 4 ,4'-methylenebis(2-methyl-6-ethylaniline), meta-phenylenediamine, meta-phenylenediamine, 4,4-diaminodiphenyl sulfone, 4,4-diaminodiphenylmethane, diethyltoluenediamine, dimethylthiotoluenediamine, 3-chloro-3'-ethyl-4,4'-diaminodiphenylmethane, 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2-ethyl)aniline, 4,4'-bis-sec-butylaminodiphenylmethane, 4,4'-methylene-bis(3-chloro-2,6-diethylaniline).

[0037] The filler is a spherical silica filler with a particle size of preferably 1 to 10 μm. The silane coupling agent contains an active group and is compatible with the epoxy resin system. The elastomer is any one of silicone rubber, butadiene rubber, styrene butadiene rubber and methacrylic acid-butadiene-styrene.

[0038] The present invention also provides a method for preparing the bottom filling glue based on the modified amine curing agent as described above, which comprises first mixing the epoxy resin, filler, silane coupling agent and elastomer, and then adding the modified amine curing agent to mix.

[0039] The preparation of the modified amine curing agent is also included, and the process is as follows:

[0040] Firstly, the aldehyde is dissolved in the amine curing agent at 40-70°C, and then the mixture is added into the ethanol solution of the phenolic compound, followed by reflux reaction at 80-95°C for 4 hours, and finally the solvent and water are evaporated at 80-100°C.

[0041] The present invention also provides a use of the bottom filling glue based on the modified amine curing agent as described above in chip packaging.

[0042] The bottom filling glue based on the modified amine curing agent of the present invention uses aldehyde and phenolic compounds to modify the amine curing agent through the Mannich reaction, and introduces the modified amine curing agent into the formula of the bottom filling glue, which can effectively improve the interface bonding strength between the bottom filling glue and the substrate (such as Si, SiN substrate), so that the bottom filling glue can still maintain a high bonding strength after PCT aging treatment, and is applied to chip packaging to improve the reliability of the package body. In addition, the preparation method of the bottom filling glue based on the modified amine curing agent of the present invention has simple steps and can be industrialized for production.

[0043] Example 1

[0044] In the formula of the bottom filling glue, the materials are selected as follows: the epoxy resin is bisphenol F type epoxy resin with an epoxy equivalent of 158; the silica filler is a silica filler surface-treated with 3-glycidoxypropyltrimethoxysilane coupling agent (average particle size: 0.5 μm); the silane coupling agent is 3-glycidoxypropyltrimethoxysilane; and the elastomer is polysiloxane powder.

[0045] In the formula of the modified amine curing agent, the materials are selected as follows: the aldehyde is polyformaldehyde, the amine curing agent is diethylenetriamine; and the phenol compound is 4-tert-butylcatechol.

[0046] The preparation process of the bottom filling glue is as follows:

[0047] (1) Preparation of modified amine curing agent: aldehyde is dissolved in an appropriate amount of amine curing agent at 60° C. and mixed evenly, then the mixture is dropped into an ethanol solution of a phenolic compound under a nitrogen atmosphere, and then the mixture is reacted at 95° C. for 4 hours. After the reaction is completed, the residual solvent and water therein are evaporated at 90° C. to obtain the modified amine curing agent.

[0048] (2) First, epoxy resin, silane coupling agent and elastomer are mixed uniformly, stirred at 1500 rpm for 2 min and at 2000 rpm for 2 min, then fillers are added to the mixture of epoxy resin, silane coupling agent and elastomer in three batches, and each batch of fillers is stirred at 1500 rpm for 2 min and at 2000 rpm for 2 min; finally, the modified amine curing agent prepared in step (1) is added to the mixture of epoxy resin, filler, silane coupling agent and elastomer, and stirred at 1500 rpm for 2 min and at 2000 rpm for 2 min, to obtain the bottom filling glue. The mass ratio of epoxy resin, modified amine curing agent, filler, silane coupling agent and elastomer is: 27.02:11.98:60:0.5:0.5.

[0049] Example 2

[0050] The difference from Example 1 is that in the formula of the modified amine curing agent, the amine curing agent is 4,4'-diaminodicyclohexylmethane, and the phenolic compound is 4-tert-butylcatechol; the mass ratio of epoxy resin, modified amine curing agent, filler, silane coupling agent and elastomer is: 23.16:15.84:60:0.5:0.5, and other material selections and processes are the same.

[0051] Example 3

[0052] The difference from Example 1 is that in the formula of the modified amine curing agent, the amine curing agent is diethyltoluenediamine, and the phenolic compound is 4-tert-butylcatechol; the mass ratio of the epoxy resin, the modified amine curing agent, the filler, the silane coupling agent and the elastomer is: 24.13:14.87:60:0.5:0.5, and the other material selections and processes are the same.

[0053] Example 4

[0054] The difference from Example 3 is that in the formula of the modified amine curing agent, the phenolic compound is 2,4-di-tert-butylphenol; the mass ratio of epoxy resin, modified amine curing agent, filler, silane coupling agent and elastomer is: 21.28:17.72:60:0.5:0.5, and other material selections and processes are the same.

[0055] Example 4

[0056] The difference from Example 3 is that in the formula of the modified amine curing agent, the phenolic compound is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; the mass ratio of epoxy resin, modified amine curing agent, filler, silane coupling agent and elastomer is: 10.07:28.93:60:0.5:0.5, and other material selections and processes are the same.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that the amine curing agent is unmodified diethylenetriamine, the mass ratio of epoxy resin, amine curing agent, filler, silane coupling agent and elastomer is 34.51:4.49:60:0.5:0.5, and other material selections and processes are the same.

[0059] Comparative Example 2

[0060] The difference from Example 2 is that the amine curing agent is 4,4'-diaminodicyclohexylmethane without modification, the mass ratio of epoxy resin, amine curing agent, filler, silane coupling agent and elastomer is 29.30:9.70:60:0.5:0.5, and other material selection and processes are the same.

[0061] Comparative Example 3

[0062] The difference from Example 3 is that the amine curing agent is unmodified diethyltoluenediamine, the mass ratio of epoxy resin, amine curing agent, filler, silane coupling agent and elastomer is 30.45:8.55:60:0.5:0.5, and other material selections and processes are the same.

[0063] The bottom filling glue prepared in Examples 1-5 and Comparative Examples 1-3 was subjected to an adhesive strength test. A sandwich structure test specimen was used. Figure 1 As shown, use a shear knife to push off the silicon chip stuck on the bottom filler, read the force value at this time, and you can get the bonding strength between the bottom filler and the silicon chip. In the PCT aging process, the prepared sandwich structure test sample is placed in a PCT aging test chamber at 121°C and 100% RH for 96 hours, and then taken out for bonding strength test.

[0064] Figure 2 This is a fracture failure mode diagram. The surface morphology of the silicon substrate of the sandwich structure that has passed the bonding strength test was photographed using a 3D confocal microscope. The interface fracture mainly manifests itself in two forms: one is the interface between the silicon chip and the bottom filling glue, and the other is the interface between the bottom filling glue and the silicon substrate. The bulk failure is the situation where the bottom filling glue is broken.

[0065] Table 1 Adhesion strength test results of bottom filling glue of Examples 1-3 and Comparative Examples 1-3

[0066]

[0067]

[0068] Table 2 Adhesion strength test results of bottom filling glue of Examples 3-4 and Comparative Example 3

[0069] Comparative Example 3 Example 3 Example 4 Example 5 Si substrate bonding strength (MPa) - initial 56.079 74.190 63.765 59.314 Si substrate bonding strength (MPa) - after PCT 45.995 70.304 58.768 54.700 SiN substrate bonding strength (MPa) - initial 58.218 71.060 61.688 55.670 SiN substrate bonding strength (MPa) - after PCT 46.886 69.059 58.038 52.170

[0070] From the test results in Table 1, it can be seen that the amine curing agent modified with aldehyde and phenolic compounds can not only significantly improve its bonding strength with Si and SiN substrates at room temperature after being introduced into the bottom filling glue, but also its bonding strength does not decrease significantly after PCT treatment. In addition, it can be seen that under the same phenolic compound, the use of curing agents similar to aromatic amines has better effects, alicyclic amine curing agents are second, and aliphatic amine curing agents are not as effective as the first two types of amine curing agents. Therefore, aromatic amine curing agents are preferred for modification.

[0071] Combination Figure 2 It can be seen that the failure modes of the embodiments are transformed from the interface failure mode to the mixed failure mode dominated by the bulk failure and the bulk failure mode compared with the corresponding comparative examples (Example 1 corresponds to Comparative Example 1, Example 2 corresponds to Comparative Example 2, and Example 3 corresponds to Comparative Example 3). This shows that the modified amine curing agent can effectively improve the interface bonding strength after being introduced into the bottom filling glue. This strong interface interaction force effectively reduces the possibility of water vapor entering the package during the PCT aging process, thereby improving the package reliability.

[0072] From the test results in Table 1, it can be seen that the amine curing agent modified with aldehyde and phenolic compounds can not only significantly improve its bonding strength with Si and SiN substrates at room temperature after being introduced into the bottom filling glue, but also its bonding strength does not decrease significantly after PCT treatment. In addition, it can be seen that the use of dihydric phenol compounds to modify aromatic amine curing agents has a better effect, and the effects of monohydric phenol and polyhydric phenol are not as good as dihydric phenol. Therefore, it is preferred to use dihydric phenol to modify aromatic amine curing agents.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A bottom filling adhesive based on a modified amine curing agent, It is characterized in that Including epoxy resin, filler, silane coupling agent, elastomer and modified amine curing agent, The epoxy resin is bisphenol F type epoxy resin, with an epoxy equivalent of 158; The filler is a silica filler, and the silica filler is a silica filler surface-treated with a 3-glycidyloxypropyltrimethoxysilane coupling agent, and the average particle size is 0.5 μm; The silane coupling agent is 3-glycidoxypropyltrimethoxysilane; The elastomer is polysiloxane powder; The modified amine curing agent is obtained by modifying the amine curing agent using aldehydes and phenolic compounds through the Mannich reaction. The chemical reaction process is shown in the following formula: The preparation process of the modified amine curing agent is as follows: The aldehyde is dissolved in an appropriate amount of an amine curing agent at 60°C and mixed evenly, and then the mixture is dropped into an ethanol solution of a phenolic compound under a nitrogen atmosphere, and then the mixture is allowed to react at 95°C for 4 hours. After the reaction is completed, the residual solvent and water therein are evaporated at 90°C to obtain the product; The aldehyde is polyformaldehyde, the amine curing agent is diethyltoluenediamine, and the phenolic compound is 4-tert-butylcatechol; the mass ratio of the epoxy resin, the modified amine curing agent, the filler, the silane coupling agent and the elastomer is: 24.13:14.87:60:0.5:0.

5.

2. The method for preparing the bottom filling adhesive based on the modified amine curing agent according to claim 1, It is characterized in that The epoxy resin, filler, silane coupling agent and elastomer are first mixed, and then the modified amine curing agent is added and mixed.

3. Use of the bottom filling adhesive as claimed in claim 1, or the bottom filling adhesive prepared by the method as claimed in claim 2, in chip packaging.

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