A moisture and heat resistant epoxy resin composition and its application in bonding and packaging of electronic components

Abstract

The present invention discloses a moisture and heat resistant epoxy resin composition and its application in bonding and encapsulating electronic components. The epoxy resin composition comprises the following components in parts by mass: 70 - 90 parts of aromatic epoxy resin, 5 - 10 parts of alicyclic epoxy resin, 5 - 20 parts of nanoparticle composite resin, 50 - 80 parts of thiol curing agent, and 0.8 - 6 parts of curing accelerator; the nanoparticle composite resin has a core-shell structure and comprises nanoparticles and a resin layer coated on the surface of the nanoparticles; the structure of the thiol curing agent is as follows: wherein, R<supgt;1< / supgt> and R<supgt;2< / supgt> are respectively C1 - C5 alkyl groups. The epoxy resin composition containing the above three resins and a specific thiol curing agent exhibits high bonding strength, high toughness, high static contact angle and low water absorption after curing, and still maintains relatively high bonding strength after high temperature and high humidity aging, and has good application prospects in the bonding and encapsulating of electronic components.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to a moisture and heat resistant epoxy resin composition and application thereof in bonding and packaging of electronic components. Background Art

[0002] Electronic packaging refers to the packaging of integrated circuit chips and their connecting components in electronic components or electronic systems to provide chip protection and support, heat dissipation, signal transmission, etc. It plays a vital role in ensuring the performance and reliability of electronic products. With the development of science and technology and the times, the requirements for electronic packaging materials are constantly being improved. Due to its advantages such as diverse curing methods, low shrinkage, high wettability, good mechanical strength and heat resistance, epoxy resin system is currently the material with the best comprehensive performance.

[0003] At present, epoxy resin compositions used for bonding and encapsulating electronic components usually contain the necessary components of epoxy resin and curing agent. Since different types of epoxy resins have different chemical structures and physical properties, different types of curing agents will react differently with epoxy resins to form different three-dimensional network structures, and the structure of the curing agent itself will also affect the moisture and heat resistance of the cured product. Therefore, the type and content of epoxy resin and the type of curing agent in the epoxy resin composition will have a significant impact on its post-curing properties (such as hardness, toughness, moisture and heat hydrolysis resistance, etc.). For example, a single bisphenol A epoxy resin has the problems of high brittleness, poor toughness and moisture and heat resistance after curing, while as an electronic component, a sealant with good toughness is required to provide better physical protection and environmental isolation. In addition, since high temperature conditions will deteriorate the performance of electronic components, adhesives and sealants used for electronic components are required to have low-temperature curing properties. Currently, the main system that meets the requirements for low-temperature, short-time curing adhesives and sealants is thiol-cured epoxy resin system. However, most commercially viable polythiols still have poor moisture and heat resistance and insufficient heat resistance after curing, and cannot meet the industrial requirement of 85°C / 85RH% / 1000H for packaging materials.

[0004] Based on this, there is an urgent need for an epoxy resin composition that can be quickly cured at low temperature and has high bonding strength, good toughness, low water absorption and good resistance to moisture and heat hydrolysis after curing, so as to meet the high performance requirements of adhesives and sealants in the bonding and packaging of electronic components. Summary of the invention

[0005] To solve the above problems, the present invention provides a moisture and heat resistant epoxy resin composition and its application in the bonding and packaging of electronic components. Under the synergistic effect of a specific resin combination and a homemade thiol curing agent, the prepared epoxy resin composition exhibits high bonding strength, high toughness, low water absorption and good moisture and heat resistance after curing.

[0006] Specifically, the following technical solutions are provided:

[0007] The first aspect of the present invention provides a moisture-heat resistant epoxy resin composition, which comprises the following components by mass: 70-90 parts of an aromatic epoxy resin, 5-10 parts of an alicyclic epoxy resin, 5-20 parts of a nanoparticle composite resin, 50-80 parts of a thiol curing agent, and 0.8-6 parts of a curing accelerator;

[0008] The nanoparticle composite resin has a core-shell structure, comprising nanoparticles and a resin layer coated on the surface of the nanoparticles;

[0009] The structure of the mercaptan curing agent is as follows:

[0010]

[0011] Among them, R 1 , R 2 They are respectively C1-C5 alkyl.

[0012] In order to solve the problem that the adhesives and encapsulants currently used for bonding or encapsulating electronic components have difficulty in achieving both bonding strength and toughness and poor moisture and heat resistance, the present invention provides a novel moisture and heat resistant epoxy resin composition, which uses an aromatic epoxy resin as a main resin component, thereby ensuring the bonding performance and strength of the epoxy resin composition after curing. However, the toughness of a single aromatic epoxy resin after curing is poor and the shrinkage and thermal expansion after curing are relatively large, thereby affecting its moisture and heat resistance. The present invention introduces an appropriate amount of alicyclic epoxy resin. Since the epoxy groups of this type of epoxy resin are directly connected to the alicyclic ring, the structure of the cured product is more stable, thereby improving the toughness of the epoxy resin composition after curing. At the same time, by introducing an appropriate amount of nanoparticle composite resin with a core-shell structure, a cross-linked network structure with a certain rigidity is formed with other resins after curing, which can not only improve the fracture toughness, but also reduce the curing shrinkage and thermal expansion of the epoxy resin composition, thereby further improving the toughness and moisture and heat resistance of the epoxy resin composition after curing. At the same time, the present invention adopts a self-made biphenyl type polythiol compound as a thiol curing agent, wherein the compound molecule contains a rigid biphenyl structure and four flexible alkylthiol groups, and the two alkylthiol groups distributed on the benzene ring are ortho positions, and the compound is used as a curing agent to cure the resin, wherein the biphenyl structure of the curing agent can give the cured resin good heat resistance, and the four thiol groups with a specific position structure can further improve the heat resistance of the cured resin through high crosslinking density and significantly improve the toughness of the cured resin, and the compound does not have an easily hydrolyzed group, which can make the resin composition containing the curing agent produce a high crosslinking density after curing and not easy to hydrolyze, thereby significantly improving the bonding strength, heat and moisture resistance, toughness, etc. of the cured resin. Under the synergistic effect of the above-mentioned resins and specific thiol curing agents, the epoxy resin composition exhibits high bonding strength, high toughness, high static contact angle, and low water absorption after curing, and still maintains a relatively high bonding strength after high temperature and high humidity aging, and can be used as an adhesive or sealant for bonding or packaging of electronic components, which is beneficial to the improvement of electronic product performance and service life.

[0013] Furthermore, the aromatic epoxy resin is preferably E51 epoxy resin and / or bisphenol F epoxy resin.

[0014] Furthermore, the alicyclic epoxy resin is preferably dicyclopentadiene epoxy resin.

[0015] Furthermore, the nanoparticles are selected from one or more of nano-silicon dioxide, titanium dioxide, aluminum oxide, nano-montmorillonite, and carbon nanotubes. The material of the resin layer is an aromatic epoxy resin and / or an alicyclic epoxy resin, such as bisphenol A epoxy resin, bisphenol F epoxy resin, dicyclopentadiene epoxy resin, etc. Preferably, the nanoparticle composite resin is a nano-silicon dioxide particle composite resin. In some preferred embodiments, the nano-silicon dioxide particle composite resin can be selected from Evonik One or more of E500, E470 and E430.

[0016] Furthermore, the mass ratio of the aromatic epoxy resin, the alicyclic epoxy resin and the nanoparticle composite resin is preferably 1:(0.08-0.12):(0.1-0.25), and more preferably 1:(0.09-0.11):(0.1-0.2).

[0017] Furthermore, the ratio of epoxy functional group equivalent to thiol functional group equivalent in the epoxy resin composition is 1:(0.9-1.2), for example, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

[0018] Furthermore, the preparation method of the mercaptan curing agent comprises the following steps:

[0019] (1) reacting 4,4'-biphenol and a compound represented by formula I in the presence of a first base reagent, a first phase transfer catalyst and a first solvent to obtain a first intermediate product represented by formula II;

[0020] (2) heating the first intermediate product to obtain a second intermediate product represented by formula III;

[0021] (3) reacting the second intermediate product with the compound represented by formula IV in the presence of a second base reagent, a second phase transfer catalyst and a second solvent to obtain a third intermediate product represented by formula V;

[0022] (4) reacting the third intermediate product with thioacetic acid in the presence of a free radical initiator and a third solvent to obtain a fourth intermediate product represented by formula VI;

[0023] (5) reacting the fourth intermediate product with an acid reagent or a base reagent in the presence of a fourth solvent to obtain the thiol curing agent;

[0024] The structures of the above formula I to formula VI are as follows:

[0025]

[0026]

[0027] Wherein, X is Cl or Br;

[0028] h is any integer from 0 to 3, and l is any integer from 0 to 3.

[0029] In some preferred embodiments, in step S1, the first alkaline reagent can be selected from one or more of potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, triethylamine, and p-dimethylaminopyridine; the first phase transfer catalyst is selected from one or more of crown ethers, onium salts, ammonium salts, sulfonium salts, arsenic salts, polyethers, non-cyclic polyethers and tertiary amine catalysts; the first solvent is selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol, and methanol; the reaction temperature is 60-90°C, and the reaction time is 6-15h.

[0030] In some preferred embodiments, in step S2, the heating reaction temperature is 150-250°C, and the heating reaction time is 10-18h.

[0031] In some preferred embodiments, in step S3, the second alkaline reagent can be selected from one or more of potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, triethylamine, and p-dimethylaminopyridine; the second phase transfer catalyst is selected from one or more of crown ethers, onium salts, ammonium salts, sulfonium salts, arsenic salts, polyethers, non-cyclic polyethers and tertiary amine catalysts; the second solvent is selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol, and methanol; the reaction temperature is 60-90°C, and the reaction time is 6-15h.

[0032] In some preferred embodiments, in step S4, the free radical initiator is selected from one or more of azo, organic peroxide and redox initiators, such as azobisisobutyronitrile or benzoyl peroxide; the third solvent is selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol, and methanol; the reaction temperature is 60-90°C, and the reaction time is 15-25h.

[0033] In some preferred embodiments, in step S5, the acid reagent is hydrochloric acid and / or sulfuric acid, and the base reagent includes but is not limited to sodium hydroxide; the fourth solvent is selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol, and methanol; the reaction temperature is 55-95°C, and the reaction time is 25-40h.

[0034] Furthermore, the curing accelerator is selected from one or more of an imidazole curing accelerator, a tertiary amine curing accelerator and a phosphorus compound curing accelerator, and is preferably PN23.

[0035] Furthermore, the epoxy resin composition further comprises 0.1-20 parts of an auxiliary agent by weight; preferably, the auxiliary agent is selected from one or more of an antioxidant, a stabilizer, an inhibitor, a flame retardant, an adhesion promoter, a coupling agent, a toughening agent, a diluent, a pigment, a defoamer, a leveling agent, a wetting agent, a leveling agent, and an ion capture agent.

[0036] Furthermore, the epoxy resin composition further comprises 0.1-40 parts of filler by mass; the filler is selected from one or more of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, boron nitride, silicon carbide, talc, calcium carbonate, glass microspheres, graphite powder, metal powder, and polytetrafluoroethylene.

[0037] The second aspect of the present invention provides a method for preparing the moisture-heat resistant epoxy resin composition described in the first aspect, comprising: weighing and mixing the components according to the formula amount, stirring and reacting for 5-15 minutes under a vacuum degree lower than -0.09 to -0.06 MPa to obtain the moisture-heat resistant epoxy resin composition; preferably, the stirring reaction temperature is room temperature and the stirring rate is 500-1000 rpm.

[0038] The third aspect of the present invention provides a use of the moisture and heat resistant epoxy resin composition described in the first aspect in preparing an adhesive for bonding electronic components.

[0039] The fourth aspect of the present invention provides a use of the moisture and heat resistant epoxy resin composition described in the first aspect in preparing a sealant for sealing electronic components.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The invention provides a novel moisture and heat resistant epoxy resin composition, comprising three different types of resins, namely, an aromatic epoxy resin, an alicyclic epoxy resin and a nanoparticle composite resin, and a thiol curing agent with a specific structure. Under the synergistic effect of the above resins and the specific thiol curing agent, the epoxy resin composition exhibits high bonding strength, high toughness, high static contact angle and low water absorption after curing, and still maintains relatively high bonding strength after high temperature and high humidity aging. The epoxy resin composition can be used as an adhesive or sealant for bonding or packaging of electronic components, which is beneficial to improving the performance and service life of electronic products.

[0042] The thiol curing agent used in the present invention has low preparation cost and is suitable for industrial mass production; more importantly, the thiol curing agent is in liquid form at room temperature and has low viscosity, and can be directly used as a curing agent in the curing process of the epoxy resin composition, so that the epoxy resin composition can be quickly cured under low temperature conditions, and the internal stress and shrinkage degree generated during curing are small. Compared with other thiol curing agents, the resin composition cured by the thiol curing agent exhibits low water absorption, better bonding strength and moisture and heat resistance, etc., and is more suitable for the bonding and sealing of electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1 1 H-NMR spectrum;

[0044] Figure 2 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1 13 C-NMR;

[0045] Figure 3 This is the IR spectrum of 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1. DETAILED DESCRIPTION

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0047] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0048] The sources of some of the raw materials used in the following examples and comparative examples are as follows:

[0049] The structure of commercial polythiol PEMP is shown below:

[0050]

[0051] The preparation of the biphenyl type polythiol compound 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl used in the following examples and comparative examples is as follows:

[0052] (1) 18.6 g of 4,4'-dihydroxybiphenyl and 36.3 g of allyl bromide were dissolved in 250 mL of acetone, and then 55.3 g of anhydrous potassium carbonate and 2.6 g of 18-crown ether-6 were added, and the mixture was stirred at 70° C. for 12 h under N2 protection. After filtering, the solvent and excess raw materials in the filtrate were removed by reduced pressure distillation, and the filtrate was washed with water and dried to obtain a first intermediate product with a yield of 94%;

[0053] (2) 26.6 g of the first intermediate product was heated to 200° C. under N2 protection for 13 h, and purified to obtain the second intermediate product with a yield of 84%;

[0054] (3) 26.6 g of the second intermediate product and 36.3 g of allyl bromide were dissolved in 250 mL of acetone, 55.3 g of anhydrous potassium carbonate and 2.6 g of 18-crown ether-6 were added, and the mixture was stirred at 70° C. for 10 h under N2 protection. After filtering, the solvent and excess raw materials in the filtrate were removed by reduced pressure distillation, and the filtrate was washed with water and dried to obtain a third intermediate product with a yield of 89%;

[0055] (4) 34.7 g of the third intermediate product and 45.7 g of thioacetic acid were dissolved in 300 mL of tetrahydrofuran, and 3.3 g of azobisisobutyronitrile was added. The mixture was stirred at 65° C. for 16 h under N2 protection. After filtering, the solvent and excess raw materials in the filtrate were removed by reduced pressure distillation. The filtrate was washed with water and dried to obtain a fourth intermediate product with a yield of 80%;

[0056] (5) 65.1 g of the fourth intermediate product and 10 g of concentrated hydrochloric acid were dissolved in 150 mL of tetrahydrofuran and 150 mL of methanol, and the mixture was stirred at 65° C. for 33 h under N2 protection. The solvent and excess raw materials in the filtrate were removed by vacuum distillation after filtration, and the mixture was washed with water and dried to obtain a liquid product 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl. Its H NMR spectrum, C NMR spectrum and IR spectrum were as follows: Figure 1-3 As shown, 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl was prepared.

[0057] Example 1

[0058] This embodiment provides an epoxy resin composition, which includes the following components by mass: 180 parts of epoxy resin E5, 8 parts of dicyclopentadiene epoxy resin, and nano-silicon dioxide particle composite resin E500 10 parts, biphenyl type polythiol compound 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl 70 parts, curing accelerator PN23 3 parts, fumed silica 1 part, stabilizer triisopropyl borate 2 parts and silane coupling agent 2 parts.

[0059] The above raw materials were added into a reaction kettle at room temperature, and then stirred at a stirring speed of 500 rpm for 10 minutes under a vacuum degree lower than -0.06 MPa to obtain a uniformly mixed epoxy resin composition.

[0060] Examples 2-9 and Comparative Examples 1-8

[0061] Examples 2-9 and Comparative Examples 1-8 respectively provide an epoxy resin composition, which differs from Example 1 only in that the type or content of the resin and / or curing agent in the formula of the epoxy resin composition is different, and the rest are the same.

[0062] The types of resins and curing agents in the epoxy resin compositions prepared in Examples 1-9 and Comparative Examples 1-8 are shown in Table 1 below, wherein the thiol curing agent A is a homemade biphenyl type polythiol compound 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl, the thiol curing agent B is a commercial polythiol PEMP, and the thiol curing agent C is 5,5'-bis(3-mercaptopropyl)-2,2'-bis(3-mercaptopropoxy)biphenyl:

[0063] Table 1

[0064]

[0065] In the table, a / b is the ratio of the epoxy functional group equivalent to the thiol functional group equivalent in the epoxy resin composition.

[0066] Performance Testing

[0067] The performance tests of the resin compositions prepared in the above examples and comparative examples are as follows:

[0068] Curing conditions: The resin compositions prepared in Examples 1-9 and Comparative Examples 1-8 were squeezed out from a rubber hose using a dispensing machine, and then cured at 80° C. for 60 minutes to obtain cured samples.

[0069] Glass transition temperature (°C): The test was carried out using the Q-800 dynamic mechanical analysis tester (DMA) of TA Instruments of the United States. The resin compositions prepared in the above embodiments and comparative examples were completely cured and made into 42 mm × 8 mm × 0.3 mm sheets. The change of the loss factor (tan δ) with temperature was measured in a liquid nitrogen atmosphere and film stretching mode within the temperature range of -40 to 250°C. The heating rate was 10°C / min and the test frequency was 10 Hz, so as to determine the glass transition temperature Tg (°C) of the resin composition after curing. The smaller the Tg value, the better the toughness of the resin after curing.

[0070] Bonding strength (MPa): The resin compositions prepared in the above embodiments and comparative examples were respectively coated on sheets to prepare test samples with a bonding area of ​​25.4 mm × 5 mm and a thickness of the adhesive layer of 0.1 mm. The test samples were cured respectively, and then the two sheets of the completely cured samples were pulled apart in opposite directions using a universal testing machine and tested at an ambient temperature of 25°C. The measured force values ​​were recorded as strength (MPa). The cured samples were subjected to heating and humidification conditions of 85°C / 85%RH / 1000h, and the shear bonding strength (MPa) of the samples was tested again at an ambient temperature of 25°C and recorded.

[0071] Water absorption rate (%): The resin compositions prepared in the above examples and comparative examples were placed in deionized water at 100°C, and after a certain period of time, they were taken out and dried, and the samples were weighed, and their water absorption rate was calculated according to the corresponding formula. The sample size was 30 mm in diameter and 2 mm in thickness. Water absorption option = (m t -m0) / m0, where m0 is the original mass of the sample, m t is the mass of the sample after time t.

[0072] Static contact angle (°): The resin compositions obtained in the above examples and comparative examples were prepared into thin films, and static contact angles were measured on the samples at room temperature using a contact angle meter using a fixed drop technique. In this experiment, the OCA20 contact angle meter from Dataphysics of Germany was used to test the hydrophilicity and hydrophobicity of the sample surface, and the measured liquid was deionized water with a surface tension of 71.97 mN / m. Each group of samples was measured 5 times, and the results were averaged.

[0073] The above test results are shown in Table 2 below:

[0074] Table 2

[0075]

[0076] As can be seen from Table 2, the adhesive layers of the epoxy resin compositions prepared in Examples 1-9 after curing exhibit high bonding strength (all higher than 18 MPa) at room temperature, which is higher than the bonding strength of the epoxy resin composition prepared using commercial polythiol PEMP as a curing agent (Comparative Example 1); and after heating and humidification treatment, they still maintain a relatively high bonding strength (not less than 14.7 MPa), showing excellent moisture and heat resistance, while the bonding strength of the epoxy resin composition prepared in Comparative Example 1 using commercial polythiol PEMP as a curing agent after heating and humidification treatment is only 7.3 MPa; in addition, the samples of the epoxy resin compositions prepared in the above embodiments have low water absorption, large static contact angle and good toughness after curing.

[0077] It can be seen from Examples 1, 6, 7 and Comparative Examples 3 and 4 that the ratio (a / b) of the epoxy functional group equivalent to the thiol functional group equivalent in the epoxy resin composition will affect the bonding strength, toughness, hydrophobicity, and moisture and heat resistance of the adhesive layer after curing. When the a / b value is 1 / 0.7 or greater than 1 / 0.9, the epoxy resin composition prepared in Comparative Example 3 does not increase the curing speed due to excessive curing addition, but leads to uneven curing; and the increase in cross-linking density will make the adhesive layer too tight and brittle, resulting in a significant decrease in bonding strength, an increase in water absorption, and poor moisture and heat resistance; when the a / b value is 1 / 1.3 or less than 1 / 1.2, the epoxy resin composition prepared in Comparative Example 4 does not change much in toughness of the cured adhesive layer due to incomplete curing and a decrease in cross-linking density, and then the room temperature bonding strength decreases, the water absorption increases, and the hydrophobicity and moisture and heat resistance deteriorate.

[0078] It can be seen from Examples 1, 8, and 9 that when the content of A2 and A3 in the epoxy resin composition is too little (Example 8), the toughness is reduced, and the bonding strength and moisture and heat resistance deteriorate; when the content of A2 and A3 in the epoxy resin composition is too much (Example 9), although the toughness is improved, the bonding strength is reduced and the water absorption rate is increased, and the moisture and heat resistance is deteriorated.

[0079] It can be seen from Example 1 and Comparative Example 2 that the position of the alkylthiol group on the benzene ring in the thiol curing agent will affect the crosslinking density of the adhesive layer after the epoxy resin composition is cured, and further affect the bonding strength, water absorption rate, etc. of the adhesive layer. Among them, the two alkylthiol groups on the benzene ring in the thiol curing agent used in Example 1 are ortho-positioned, and the adhesive layer prepared by curing the epoxy resin with the compound has better toughness, bonding strength, moisture and heat resistance, low water absorption rate, etc.

[0080] It can be seen from Example 1 and Comparative Examples 5-7 that the type of monomer in the epoxy resin composition will affect the bonding strength and hydrophobicity of the glue layer after curing. When the epoxy resin composition only contains aromatic resin monomers, the prepared glue layer (Comparative Example 5) has better hydrophobicity, but lower bonding strength; and the epoxy resin polymer (Comparative Example 6) prepared by using butyl glycidyl ether instead of alicyclic monomers not only has lower bonding strength but also high water absorption, which is not suitable for bonding and packaging of electronic products. If only aromatic resin monomers and nanoparticle composite resin monomers are used as resin monomers to prepare the epoxy resin composition (Comparative Example 7), the adhesive layer formed by curing has low bonding strength and poor moisture and heat resistance.

[0081] It can be seen from Example 1 and Comparative Example 8 that when the content of resin A2 and A3 in the epoxy resin composition is too high, the bonding strength is significantly reduced, and the water absorption rate is as high as 3.5, the hydrophobicity is poor, and it is not suitable for bonding and packaging of electronic products.

[0082] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A moisture and heat resistant epoxy resin composition, characterized in that: The epoxy resin composition comprises the following components by mass: 70-90 parts of aromatic epoxy resin, 5-10 parts of alicyclic epoxy resin, 5-20 parts of nanoparticle composite resin, 50-80 parts of thiol curing agent, and 0.8-6 parts of curing accelerator; The nanoparticle composite resin has a core-shell structure, comprising nanoparticles and a resin layer coated on the surface of the nanoparticles, wherein the material of the resin layer is an aromatic epoxy resin and / or an alicyclic epoxy resin; The structure of the mercaptan curing agent is as follows: ， Among them, R 1 , R 2 are C1-C5 alkyl respectively; The mass ratio of the aromatic epoxy resin, the alicyclic epoxy resin and the nanoparticle composite resin is 1: (0.08-0.12): (0.1-0.25); The ratio of the epoxy functional group equivalent to the thiol functional group equivalent in the epoxy resin composition is 1:(0.9-1.2).

2. The moisture-heat resistant epoxy resin composition according to claim 1, characterized in that: The aromatic epoxy resin is E51 epoxy resin and / or bisphenol F epoxy resin; The alicyclic epoxy resin includes dicyclopentadiene epoxy resin; The nanoparticles in the nanoparticle composite resin are selected from one or more of nano-silicon dioxide, titanium dioxide, aluminum oxide, nano-montmorillonite and carbon nanotubes.

3. The heat-resistant epoxy resin composition according to claim 2, characterized in that: The nanoparticle composite resin is selected from the nano-silicon dioxide particle composite resin Nanopox ® One or more of E500, E470 and E430.

4. The moisture-heat resistant epoxy resin composition according to claim 1, characterized in that: The curing accelerator is selected from one or more of an imidazole-based curing accelerator, a tertiary amine-based curing accelerator, and a phosphorus compound-based curing accelerator.

5. The moisture-heat resistant epoxy resin composition according to claim 1, characterized in that: The epoxy resin composition further comprises 0.1-20 parts of an auxiliary agent by weight; The auxiliary agent is selected from one or more of antioxidants, stabilizers, polymerization inhibitors, flame retardants, adhesion promoters, coupling agents, toughening agents, diluents, pigments, defoamers, leveling agents, wetting agents, homogenizers, and ion capture agents.

6. The moisture-heat resistant epoxy resin composition according to claim 1, characterized in that: The epoxy resin composition further comprises 0.1-40 parts of filler by weight; The filler is selected from one or more of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, boron nitride, silicon carbide, talc, calcium carbonate, glass microspheres, graphite powder, metal powder, and polytetrafluoroethylene.

7. A method for preparing the moisture-heat resistant epoxy resin composition according to any one of claims 1 to 6, characterized in that: The components are weighed and mixed according to the formula, and stirred for reaction for 5-15 minutes under the condition of a vacuum degree lower than -0.09 to -0.06 MPa to obtain the moisture and heat resistant epoxy resin composition.

8. Use of the moisture and heat resistant epoxy resin composition according to any one of claims 1 to 6 in preparing an adhesive for bonding electronic components.

9. Use of the moisture and heat resistant epoxy resin composition according to any one of claims 1 to 6 in preparing a sealant for sealing electronic components.

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