Preparation process of high-thermal-conductivity low-expansion electronic-grade modified amine curing agent

Abstract

The invention discloses a preparation process of a high-thermal-conductivity low-expansion electronic-grade modified amine hardener, and belongs to the technical field of heat-conducting materials.According to the amine hardener, 1, 6-dibromo pyrene and nitrophenylboronic acid are subjected to Suzuki reaction and nitro ring closing to prepare a macrocyclic aromatic amine product B, and then 1-bromo-4-iodobenzene-mediated Buchwald-Harwig coupling is performed to obtain the high-thermal-conductivity low-expansion electronic-grade modified amine hardener. And connecting the product B with melamine to obtain the product. The plane rigidity of the main body macrocyclic aromatic amine inhibits the disordered conformation change of molecules at high temperature and reduces the phonon transfer loss; pi-Pi accumulation exists in a large-plane benzene ring to form high crystallinity, gaps can be reduced, and an efficient heat conduction channel can be constructed; the polyfunctionality-NH-bond and epoxy resin can form a three-dimensional cross-linked network, and a heat-conducting network penetrating through the whole body is formed so as to improve the heat-conducting property; thermal expansion is inhibited through cooperation of the rigid large ring pi-pi effect and the high crosslinking degree; and the polar-NH-bond also enhances the adhesive force of the packaging layer to the substrate through the hydrogen bond and the coordination bond of the metal substrate.

Description

Technical Field

[0001] This invention relates to the field of thermally conductive materials technology, specifically to a preparation process for a high thermal conductivity, low expansion electronically modified amine curing agent. Background Technology

[0002] With the rapid development of 5G communication, new energy vehicle electronics, high-power chips and other fields, the power density of electronic components continues to increase, and the amount of heat generated per unit volume surges. If the heat cannot be dissipated in time, it will affect the reliability and service life of electronic components. At the same time, precision electronic packaging has strict requirements for dimensional stability, which poses a dual challenge to the high thermal conductivity and low expansion characteristics of epoxy molding compounds used in electronic packaging.

[0003] The main ways to achieve high thermal conductivity and low expansion properties in epoxy molding compounds are by filling with thermally conductive powder and by adjusting the polymer structure of the epoxy resin itself. Thermally conductive powder can be embedded in polymer pores to suppress molecular chain movement; adjusting the polymer structure of the epoxy resin itself involves changing the polymer's crystallinity and crosslinking degree. These two factors work synergistically to reduce molecular vibrations and lattice incoordination, thereby reducing phonon scattering and improving thermal conductivity. They also increase rigidity and interchain interactions to mitigate the epoxy resin expansion caused by thermally induced violent molecular chain movement. Polymer structure adjustment is generally achieved by changing the type of epoxy resin and curing agent. In terms of curing agents, commonly used amine curing agents are mostly difunctional linear flexible aliphatic amines or sterically hindered aromatic amines, which have significant limitations: On the one hand, their molecular structure is small, and the molecular chains and atoms on the chains move violently, making it impossible to achieve high crystallinity or orientation. The lack of thermal conductivity means that phonons dissipate energy through scattering and cannot transfer heat, making it difficult to meet the requirements of efficient heat dissipation. On the other hand, the network structure formed by the cross-linking of amine curing agents and epoxy resin is not rigid enough, has a low glass transition temperature, and a high coefficient of thermal expansion. It is prone to interfacial stress due to thermal cycling, which can cause cracking and peeling of the encapsulation layer and damage the stability of electronic components. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the present invention provides a high thermal conductivity, low expansion electronic grade modified amine curing agent and its preparation process. The high thermal conductivity, low expansion electronic grade modified amine curing agent is prepared by reacting 1,6-dibromopyrene with nitrophenylboronic acid via Suzuki reaction and nitro ring-closing reaction to prepare macrocyclic aromatic amine product B as the main structure, and then connecting product B with melamine via 1-bromo-4-iodobenzene through Buchwald–Hartwig coupling reaction. On the one hand, the main structure of the curing agent is a macrocyclic aromatic amine, which has high planar rigidity, restricting the flexible movements of molecular chains such as rotation and bending. When the temperature changes, the molecules only undergo small-amplitude movements rather than disordered conformational changes, thereby reducing the loss of phonons during transmission and allowing phonons to be smoothly transmitted along the macrocyclic skeleton. On the other hand, the large planar structure can easily form a regular molecular arrangement through π-π stacking or strong van der Waals forces, achieving high crystallinity. High crystallinity reduces the gaps that cause phonon scattering, while the orderly arrangement creates an efficient heat conduction channel for phonon transmission. In addition, the introduction of melamine gives the curing agent multifunctional polar -NH- bonds, which can not only form a three-dimensional dense cross-linked network with the resin, "anchoring" the dispersed planar rigid macrocycles together to form a rigid thermally conductive network that runs through the polymer, but also disperse and fix thermally conductive powder, reduce the migration of thermally conductive powder, and further improve the thermal conductivity of the material. Among these features, the strong π-π interactions between the rigid macrocyclic molecular skeleton and the benzene ring plane, along with the high degree of cross-linking formed by multiple functionalities, can resist deformation caused by high-temperature thermal motion, suppress material expansion, and endow the material with a low coefficient of thermal expansion. Moreover, the polar -NH- bonds not only promote cross-linking but can also form hydrogen bonds with the polar -OH groups of the oxide layer on the surface of the metal substrate. At the same time, the N atom has lone pairs of electrons, which can form coordinate bonds with the metal. The synergistic effect of these two factors endows the substrate with good adhesion.

[0005] The purpose of this invention is to provide a high thermal conductivity, low expansion electronic-grade modified amine curing agent and its preparation process.

[0006] This invention is achieved through the following technical solution: A high thermal conductivity, low expansion electronic-grade modified amine curing agent, wherein the structural formula of the high thermal conductivity, low expansion electronic-grade modified amine curing agent is shown in Formula 1: Formula 1.

[0007] Another object of the present invention is to protect a preparation process for a high thermal conductivity, low expansion electronic-grade modified amine curing agent, comprising the following steps: S1. Under nitrogen atmosphere, aromatic dibromo derivative and 2-nitrophenylboronic acid were dissolved in toluene, and an inorganic base and phase transfer agent were added. Tetra(triphenylphosphine)palladium was then added as a catalyst and the reaction was heated. The reaction solution was cooled, diluted with ethanol and dichloromethane, filtered, the filtrate was concentrated, and purified by silica gel column chromatography to obtain product A. S2. Under nitrogen conditions, product A was dissolved in a solvent, and then an oxygen-loving reducing agent was added. The reaction was heated and the solution was cooled. The solvent was evaporated at 140-150 °C using a vacuum pump under reduced pressure and purified by silica gel column chromatography to obtain product B. S3. Under nitrogen conditions, product B, 1-bromo-4-iodobenzene, base, and ligand are dissolved in anhydrous solvent and aerated for 15-30 minutes; then copper catalyst is added and the reaction is heated; the reaction solution is cooled, saturated brine is added for salting out, the mixture is filtered, the filter cake is dissolved and concentrated, and purified by silica gel column chromatography to obtain the disubstituted product C. S4. Under nitrogen conditions, melamine, a strong base, and the ligand dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl were dissolved in DMF, and Pd2(dba)3 was added as a catalyst and the temperature was raised. Product C was added dropwise. After the reaction was completed, the reaction solution was cooled, saturated brine was added for salting out, the mixture was filtered, the filter cake was dissolved and concentrated, and purified by silica gel column chromatography to obtain a high thermal conductivity, low expansion electronic grade modified amine curing agent.

[0008] In a specific example, in step S1, the aromatic dibromo derivative is one of 1,6-dibromopyrene; the amount of 2-nitrophenylboronic acid is 2.1-2.5 times the molar amount of the aromatic dibromo derivative; the inorganic base is one of potassium carbonate or sodium carbonate, and the amount is 6-10 times the molar amount of the aromatic dibromo derivative, with an aqueous solution concentration of 2 M; the phase transfer agent is methyltrioctylammonium chloride, and the amount is 0.1-0.2 wt% of the aromatic dibromo derivative; the amount of tetra(triphenylphosphine)palladium is 1-5 wt% of the sum of the masses of the aromatic dibromo derivative and 2-nitrophenylboronic acid; the reaction temperature is 100-120 °C, and the reaction time is 8-14 hours.

[0009] In a specific example, in step S2, the solvent is one or a combination of o-dichlorobenzene and chlorobenzene; the oxyphilic reducing agent is triphenylphosphine, and the amount used is 4.1-5.2 times the molar amount of product A; the reaction temperature is 180-200 ℃, and the reaction time is 24-48 hours until the reaction is completed.

[0010] In a specific example, in step S3, the amount of 1-bromo-4-iodobenzene used is 2.05-2.5 times the molar amount of product B; the base is cesium carbonate, used in an amount 4-6 times the molar amount of product B; the ligand is 9,10-phenanthrenequinone, used in an amount 0.25-0.3 times the molar amount of 1-bromo-4-iodobenzene; the anhydrous solvent is one of DMF and 1,4-dioxane; the copper catalyst is cuprous iodide, used in an amount 0.205-0.25 times the molar amount of 1-bromo-4-iodobenzene; the reaction temperature is 130-140 °C, and the reaction time is 24-30 hours.

[0011] In a specific example, in step S4, the amount of melamine used is 2.01-2.2 times the molar amount of product C; the strong base is one of cesium carbonate, potassium tert-butoxide, and sodium tert-butoxide, and the amount used is 5-8 times the molar amount of product C; the amount of dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl used is 2-10 wt% of the total mass of product C and melamine; the amount of Pd2(dba)3 used is 1-5 wt% of the total mass of product C and melamine; the reaction temperature is 80-100 ℃, and the time is 24-36 hours.

[0012] Another object of the present invention is to protect the application of the high thermal conductivity, low expansion electronic-grade modified amine curing agent or the high thermal conductivity, low expansion electronic-grade modified amine curing agent prepared by the preparation process of the high thermal conductivity, low expansion electronic-grade modified amine curing agent in epoxy molding compounds for electronic packaging: An epoxy molding compound for electronic packaging comprises, by weight, the following components: 100 parts epoxy resin, 20-50 parts high thermal conductivity and low expansion electronic grade modified amine curing agent, 80-200 parts thermally conductive powder particles, and 2-8 parts silane coupling agent.

[0013] In one specific example, the epoxy resin is selected from DOW epoxy resin DER-332 with an epoxy equivalent of 179-183 g / eq; the thermally conductive powder particles are selected from a combination of hexagonal boron nitride and spherical alumina.

[0014] Beneficial effects

[0015] This invention provides a high thermal conductivity, low expansion, electronically modified amine curing agent and its preparation process. The high thermal conductivity, low expansion, electronically modified amine curing agent is prepared by reacting 1,6-dibromopyrene with nitrophenylboronic acid via the Suzuki reaction and nitro ring-closing reaction to prepare macrocyclic aromatic amine product B as the main structure. Then, product B is connected to melamine via a Buchwald–Hartwig coupling reaction using 1-bromo-4-iodobenzene. On the one hand, the main structure of the curing agent is a macrocyclic aromatic amine, which has high planar rigidity, restricting the flexible movements of molecular chains such as rotation and bending. When the temperature changes, the molecules only undergo small-amplitude movements rather than disordered conformational changes, thereby reducing phonon loss during transmission and allowing phonons to be smoothly transmitted along the macrocyclic skeleton. On the other hand, the large planar structure can easily form a regular molecular arrangement through π-π stacking or strong van der Waals forces, achieving high crystallinity. High crystallinity reduces the gaps that cause phonon scattering, while the orderly arrangement creates an efficient heat conduction channel for phonon transmission. In addition, the introduction of melamine gives the curing agent multifunctional polar -NH- bonds, which can not only form a three-dimensional dense cross-linked network with the resin, "anchoring" the dispersed planar rigid macrocycles together to form a rigid thermally conductive network that runs through the polymer, but also disperse and fix thermally conductive powder, reducing the migration of thermally conductive powder and giving the material excellent thermal conductivity. Among these features, the strong π-π interactions between the rigid macrocyclic molecular skeleton and the benzene ring plane, along with the high degree of cross-linking formed by multiple functionalities, can resist deformation caused by high-temperature thermal motion, suppress material expansion, and endow the material with a low coefficient of thermal expansion. Moreover, the polar -NH- bonds not only promote cross-linking but can also form hydrogen bonds with the polar -OH groups of the oxide layer on the surface of the metal substrate. At the same time, the N atom has lone pairs of electrons, which can form coordinate bonds with the metal. The synergistic effect of these two factors endows the substrate with good adhesion. Attached Figure Description

[0016] Figure 1 Synthetic route for electronically modified amine curing agents with high thermal conductivity and low expansion; Figure 2 The 1H NMR spectrum of the electronically modified amine curing agent with high thermal conductivity and low expansion. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0019] The raw materials used in the examples and comparative examples are described below: Aromatic dibromo derivative: 1,6-dibromopyrene, 98%, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; 2-Nitrophenylboronic acid: 98%, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Phase transfer agent: Methyltrioctylammonium chloride (Aliquat336), 97%, product number BD112948, purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd.; Tetra(triphenylphosphine)palladium (Pd(PPh3)4): 97%, purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd.; o-Dichlorobenzene (o-DCB): 98%, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Oxyphilic reducing agent: Triphenylphosphine, 99.8%, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; 1-Bromo-4-iodobenzene: 98%, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Ligand: 9,10-phenanthrenequinone (9,10-PQ), 95%, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Tris(dibenzylacetone)dipalladium(0) (Pd2(dba)3), 98%, product number BD21135, purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd. 2-Dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl (Ruphos), 97%, purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd.; Melamine: Purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Thermal conductive powder particles 1: hexagonal boron nitride, 99.9%, 2-5 μm, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Thermal conductive powder particles 2: spherical alumina, ≥99.5%, 6 μm, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Epoxy resin: DOW epoxy resin DER-332, epoxy equivalent 179-183 g / eq, viscosity 9000-10500 cps@25 ℃, purchased from Dow Chemical Company, USA; Silane coupling agent: KH570, 99%, purchased from Shandong Yifei Science and Trade Co., Ltd.

[0020] Example

[0021] High thermal conductivity, low expansion electronic-grade modified amine curing agent: Preparation method is as follows: S1. Under nitrogen atmosphere, 1,6-dibromopyrene (1 molar equivalent) and 2-nitrophenylboronic acid (2.2 molar equivalent) were dissolved in toluene, and potassium carbonate (8 molar equivalent, 2 M) and methyltrioctylammonium chloride (0.15 wt% of the mass of 1,6-dibromopyrene) were added. The mixture was bubbled and aerated for 30 minutes. Then, tetra(triphenylphosphine)palladium was added as a catalyst (3 wt% of the combined mass of 1,6-dibromopyrene and 2-nitrophenylboronic acid), and the mixture was aerated for another 10 minutes. The mixture was heated to 110 °C and stirred for 10 hours until the reaction was complete. The mixture was cooled, diluted with ethanol and dichloromethane, filtered, concentrated, and purified by silica gel column chromatography to obtain product A, with a yield of 86%. S2. Under nitrogen atmosphere, product A (1 molar equivalent) was dissolved in o-dichlorobenzene and bubbled for 30 minutes; then triphenylphosphine (4.5 molar equivalent) was added and bubbled for 10 minutes; the mixture was heated to 185 °C and stirred for 36 hours until the reaction was complete; the mixture was cooled, the o-dichlorobenzene was evaporated at 150 °C using a vacuum filtration pump, and purified by silica gel column chromatography to obtain product B, with a yield of 89%. S3. Under nitrogen atmosphere, product B (1 molar equivalent), 1-bromo-4-iodobenzene (2.2 molar equivalent), cesium carbonate (5 molar equivalent), and 9,10-phenanthrenequinone (0.25 molar equivalent) were dissolved in anhydrous DMF and stirred for 30 minutes. Cuprous iodide (0.21 molar equivalent) was then added and stirred for 10 minutes. The temperature was raised to 135 °C and stirred for 28 hours until the reaction was complete. After cooling, saturated brine was added for salting out, followed by filtration, dissolution of the filter cake, concentration, and purification by silica gel column chromatography to obtain the disubstituted product C with a yield of 67%. The reaction under these conditions showed high selectivity, and the bromine atom did not compete with the iodine atom for the reaction.

[0022] S4. Under nitrogen atmosphere, melamine (2.1 molar equivalents), cesium carbonate (6 molar equivalents), and ligand dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl (5 wt%) were dissolved in DMF and bubbled for 30 minutes. Catalyst Pd2(dba)3 (2.5 wt%) was added, and the mixture was bubbled for another 10 minutes. The temperature was raised to 90 °C. Product C (1 molar equivalent) was dissolved in DMF and added dropwise to the melamine solution, completing the addition within 1 hour. The reaction was stirred for 30 hours until completion. After cooling, saturated brine was added for salting out, followed by filtration, dissolving the filter cake, concentration, and silica gel column purification to obtain a high thermal conductivity, low expansion electronic-grade modified amine curing agent with a yield of 87%.

[0023] Comparative Example For melamine-benzene curing agent: self-made, the preparation method differs from that of high thermal conductivity, low expansion electronic grade modified amine curing agent in that only step S4 is performed, and product C is replaced with p-dibromobenzene.

[0024] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0025] Application examples An epoxy molding compound prepared from a high thermal conductivity, low expansion electronic-grade modified amine curing agent, the weight parts of which are shown in Table 1, and the preparation method is as follows: Epoxy resin, high thermal conductivity and low expansion electronic grade modified amine curing agent, thermally conductive powder particles (boron nitride and alumina mass ratio of 2-3:1), and silane coupling agent are placed in a mixer and stirred for 5-10 minutes at 900-1100 r / min to obtain an epoxy molding compound prepared with high thermal conductivity and low expansion electronic grade modified amine curing agent.

[0026] An epoxy molding compound prepared by a high thermal conductivity and low expansion electronic grade modified amine curing agent was coated on the surface of an insulating aluminum substrate with a coating thickness of 50-100 μm and then cured at 130-280 ℃ for 30-120 minutes to obtain a cured high thermal conductivity and low expansion epoxy molding compound, which was then used for subsequent performance testing.

[0027] Table 1. Epoxy molding compound (parts by weight) prepared from a high thermal conductivity, low expansion electronic-grade modified amine curing agent.

[0028] The epoxy molding compound prepared with a high thermal conductivity, low expansion electronic-grade modified amine curing agent prepared in the examples and comparative examples was subjected to the following performance tests, and the results are attached. Figure 2 As shown in Table 2.

[0029] 1. Proton NMR Spectroscopy: The synthesized high thermal conductivity, low expansion electronic-grade modified amine curing agent sample was dissolved in deuterated DMSO to prepare a 1.0 wt% solution. The NMR spectrum of the sample was measured using a proton NMR spectrometer at 400 MHz. The results are as follows: Figure 2 As shown, the integral number is consistent with the hydrogen number of the high thermal conductivity, low expansion electronic-grade modified amine curing agent, and the chemical shift is consistent with its chemical environment, indicating that the target product has been synthesized.

[0030] 2. High Temperature Storage Test (HTST): The fully cured coating is kept at 180 °C for 1000 hours to observe whether the encapsulation layer obtained after the epoxy molding compound has cured is intact.

[0031] 3. High and low temperature cycling test (TCT): The fully cured coating is cycled 1000 times in the temperature range of -55-180 ℃, and the integrity of the encapsulation layer obtained after the epoxy molding compound is observed.

[0032] 4. Thermal conductivity test: The thermal conductivity of the encapsulation layer sample was tested using a TPS2200 thermal constant analyzer from HotDiSk, Sweden.

[0033] 5. Coefficient of thermal expansion (CTE): The coefficient of thermal expansion is tested according to GB / T 1036-2004 standard, and the test temperature is 180-220 ℃.

[0034] 6. Substrate adhesion: The epoxy molding compound film was subjected to a cross-cut adhesion test according to GB / T9286-1998. The epoxy molding compound was coated on an insulating aluminum substrate with a size of 0.2*0.2cm and a thickness of 100 μm. It was cured at 180 ℃ for 3 hours, and then placed at 25 ℃ and 200 ℃ respectively. The adhesion grade was tested by cutting a 10*10 grid on the coating surface, ranging from 0 to 5, where the adhesion gradually decreases.

[0035] Table 2 Performance test results of epoxy molding compound coating prepared with a high thermal conductivity, low expansion electronic grade modified amine curing agent

[0036] As shown in Table 2, with the decrease in the number of rigid planar benzene rings and polar -NH- bonds in the curing agents of Examples 1, 1, 2, and 3, the degree of crosslinking of the polymers obtained by crosslinking with epoxy resin decreased. Interchain interactions such as hydrogen bonds, van der Waals forces, and π-π interactions also decreased, making it impossible to restrict molecular chain movement through interchain interactions. Consequently, crystallization could not be effectively promoted, resulting in strong molecular and lattice vibrations and strong phonon scattering. This led to a decrease in thermal conductivity and an increase in the coefficient of thermal expansion. In Comparative Example 4, the coating prepared using epoxy resin and propylenediamine, which had relatively low rigidity and cross-functionality, exhibited a significant decrease in thermal conductivity and a dramatic increase in the coefficient of thermal expansion, further illustrating the important role of the curing agent in improving thermal conductivity and reducing thermal expansion.

[0037] The polar -NH- bonds not only promote crosslinking and affect the thermal conductivity and coefficient of thermal expansion, but also largely determine the substrate adhesion. The polar -NH- bonds can form hydrogen bonds with the polar -OH groups of the oxide layer on the surface of the metal substrate. At the same time, the N atom has lone pair electrons and can form coordinate bonds with the metal. The synergistic effect of the two gives the substrate good adhesion. As a result, the substrates of the examples with more -NH- bonds and Comparative Example 1 have higher adhesion.

[0038] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high thermal conductivity, low expansion electronic-grade modified amine curing agent, characterized in that, The structural formula of the high thermal conductivity, low expansion electronic grade modified amine curing agent is shown in Formula 1: Formula 1.

2. A preparation process for a high thermal conductivity, low expansion electronic-grade modified amine curing agent, characterized in that, Includes the following steps: S1. Under nitrogen atmosphere, aromatic dibromo derivative and 2-nitrophenylboronic acid were dissolved in toluene, and an inorganic base and phase transfer agent were added. Tetra(triphenylphosphine)palladium was then added as a catalyst and the reaction was heated. The reaction solution was cooled, diluted with ethanol and dichloromethane, filtered, the filtrate was concentrated, and purified by silica gel column chromatography to obtain product A. S2. Under nitrogen conditions, product A was dissolved in a solvent, and then an oxygen-loving reducing agent was added. The reaction was heated and the solution was cooled. The solvent was evaporated at 140-150 °C using a vacuum pump under reduced pressure and purified by silica gel column chromatography to obtain product B. S3. Under nitrogen conditions, product B, 1-bromo-4-iodobenzene, base, and ligand are dissolved in anhydrous solvent and aerated for 15-30 minutes; then copper catalyst is added and the reaction is heated; the reaction solution is cooled, saturated brine is added for salting out, the mixture is filtered, the filter cake is dissolved and concentrated, and purified by silica gel column chromatography to obtain the disubstituted product C. S4. Under nitrogen conditions, melamine, a strong base and ligands, and dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl were dissolved in DMF, and Pd2(dba)3 was added as a catalyst and the temperature was raised. Product C was added dropwise. After the reaction was completed, the reaction solution was cooled, saturated brine was added for salting out, the mixture was filtered, the filter cake was dissolved and concentrated, and purified by silica gel column chromatography to obtain a high thermal conductivity, low expansion electronic grade modified amine curing agent.

3. The preparation process of the high thermal conductivity, low expansion electronic-grade modified amine curing agent as described in claim 2, characterized in that, In step S1, the aromatic dibromo derivative is 1,6-dibromopyrene; the amount of 2-nitrophenylboronic acid is 2.1-2.5 times the molar amount of the aromatic dibromo derivative; the inorganic base is either potassium carbonate or sodium carbonate, and the amount is 6-10 times the molar amount of the aromatic dibromo derivative, with an aqueous solution concentration of 2 M; the phase transfer agent is methyltrioctylammonium chloride, and the amount is 0.1-0.2 wt% of the aromatic dibromo derivative; the amount of tetra(triphenylphosphine)palladium is 1-5 wt% of the combined mass of the aromatic dibromo derivative and 2-nitrophenylboronic acid; the reaction temperature is 100-120 °C, and the reaction time is 8-14 hours.

4. The preparation process of the high thermal conductivity, low expansion electronic-grade modified amine curing agent as described in claim 2, characterized in that, In step S2, the solvent is one or a combination of o-dichlorobenzene and chlorobenzene; the oxyphilic reducing agent is triphenylphosphine, and the amount used is 4.1-5.2 times the molar amount of product A; the reaction temperature is 180-200 ℃, and the reaction time is 24-48 hours.

5. The preparation process of the high thermal conductivity, low expansion electronic-grade modified amine curing agent as described in claim 2, characterized in that, In step S3, the amount of 1-bromo-4-iodobenzene used is 2.05-2.5 times the molar amount of product B; the base is cesium carbonate, and the amount used is 4-6 times the molar amount of product B; the ligand is 9,10-phenanthrenequinone, and the amount used is 0.25-0.3 times the molar amount of 1-bromo-4-iodobenzene; the anhydrous solvent is one of DMF and 1,4-dioxane; the copper catalyst is cuprous iodide, and the amount used is 0.205-0.25 times the molar amount of 1-bromo-4-iodobenzene; the reaction temperature is 130-140 °C, and the reaction time is 24-30 hours.

6. The preparation process of the high thermal conductivity, low expansion electronic-grade modified amine curing agent as described in claim 2, characterized in that, In step S4, the amount of melamine used is 2.01-2.2 times the molar amount of product C; the strong base is one of cesium carbonate, potassium tert-butoxide, and sodium tert-butoxide, and the amount used is 5-8 times the molar amount of product C; the amount of dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl used is 2-10 wt% of the total mass of product C and melamine; the amount of Pd2(dba)3 used is 1-5 wt% of the total mass of product C and melamine; the reaction temperature is 80-100 ℃, and the reaction time is 24-36 hours.

7. The application of the high thermal conductivity and low expansion electronic grade modified amine curing agent prepared by the preparation process of the high thermal conductivity and low expansion electronic grade modified amine curing agent as described in claim 1 or any one of claims 2 to 6 in the curing agent of epoxy molding compound for electronic packaging.

8. An epoxy molding compound for electronic packaging, characterized in that, The product comprises the following components by weight: 100 parts epoxy resin, 20-50 parts of the high thermal conductivity, low expansion electronic grade modified amine curing agent as described in claim 1, 80-200 parts thermally conductive powder particles, and 2-8 parts silane coupling agent.

9. The epoxy molding compound for electronic packaging as described in claim 8, characterized in that, The epoxy resin is selected from DOW epoxy resin DER-332, with an epoxy equivalent of 179-183 g / eq; the thermally conductive powder particles are selected from a combination of hexagonal boron nitride and spherical alumina.

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