High-performance electronic encapsulating material and preparation method thereof

Abstract

The invention relates to the field of encapsulating material preparation, and particularly discloses a high-performance electronic encapsulating material and a preparation method thereof. The high-performance electronic encapsulating material is prepared from the following raw materials in parts by weight: 10-12 parts of modified epoxy resin, 6-8 parts of polymethylphenylsiloxane, 1-3 parts of a phenolic aldehyde amine curing agent, 2-4 parts of spherical silicon dioxide, 0.5-1 part of a silane coupling agent, 3-5 parts of silicalite, 5-7 parts of hexagonal boron nitride, 0.5-1 part of a curing accelerator and 2-4 parts of propylene glycol monomethyl ether. The composition disclosed by the invention can be used for packaging electronic components and has the advantages of high temperature resistance and good heat-conducting property.

Description

Technical Field

[0001] This application relates to the technical field of encapsulation material preparation, and more specifically, it relates to a high-performance electronic encapsulant and its preparation method. Background Art

[0002] High-performance electronic encapsulants are core materials in the field of electronic component packaging, mainly used to protect the stable operation of precision components such as chips and sensors under extreme working conditions such as high temperature and high power density. With the rapid development of electronic devices towards miniaturization, high frequency, and high power, the encapsulation materials need to meet the dual requirements of high temperature resistance and high thermal conductivity simultaneously: on the one hand, they need to maintain structural stability at continuous high temperature (>200 °C) to avoid failure caused by thermal degradation or stress deformation; on the other hand, they need to quickly conduct the heat generated during device operation to prevent performance degradation or damage caused by local temperature rise.

[0003] However, the material design in related technologies often faces the contradiction that it is difficult to optimize the two aspects synergistically. For example, improving the high temperature resistance usually requires enhancing the cross-linking density of the material or introducing a rigid structure, but such designs are likely to increase brittleness or the coefficient of thermal expansion, which instead exacerbates the interfacial thermal resistance; while simply increasing the amount of thermal conductive filler can improve the thermal conductivity, but it may cause problems such as a decrease in mechanical strength and deterioration of processing performance due to uneven dispersion of the filler or poor interfacial bonding. In addition, the oxidative degradation of the resin matrix and the accumulation of interfacial thermal stress between the filler and the matrix in a high temperature environment further restrict the long-term reliability of the material. Summary of the Invention

[0004] In order to improve the high temperature resistance and thermal conductivity of the material, this application provides a high-performance electronic encapsulant and its preparation method.

[0005] In the first aspect, a high-performance electronic encapsulant provided by this application adopts the following technical solution: A high-performance electronic encapsulant, comprising the following raw materials in parts by weight: 10 - 12 parts of modified epoxy resin, 6 - 8 parts of polymethylphenylsiloxane, 1 - 3 parts of phenolic amine curing agent, 2 - 4 parts of spherical silica, 0.5 - 1 part of silane coupling agent, 3 - 5 parts of silicalite, 5 - 7 parts of hexagonal boron nitride, 0.5 - 1 part of curing accelerator, 2 - 4 parts of propylene glycol methyl ether.

[0006] By adopting the above technical solutions, the modified epoxy resin provides basic adhesion and mechanical strength. In combination with polymethylphenylsiloxane, it increases the flexibility and weather resistance of the material, enabling the encapsulation material to maintain stable performance in different environments. The phenolic amine curing agent reacts with the epoxy resin to form a high cross-linking density network, further enhancing the thermal stability. Spherical silica and hexagonal boron nitride, as highly efficient thermal conductive fillers, not only enhance the mechanical strength of the material but also significantly improve the thermal conductivity. The application of silane coupling agent optimizes the interfacial bonding between the filler and the matrix, reducing the interfacial thermal resistance. The addition of silicalite helps to regulate humidity and improve environmental adaptability. Finally, the curing accelerator ensures rapid and complete curing of the entire system, thus guaranteeing the excellent comprehensive performance of the final product, including good high-temperature resistance, high thermal conductivity, and mechanical strength, meeting the requirements of modern high-performance electronic devices for encapsulation materials.

[0007] Optionally, the preparation of the modified epoxy resin includes the following steps: Mix epoxy resin with 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl and heat it in an oil bath at 70 - 90 °C for stirring reaction for 40 - 60 min to form a prepolymer. Dissolve 2-ethyl-4-methylimidazole in propylene glycol methyl ether and drop it into the prepolymer within 30 min while performing vacuum decompression treatment. After dropping, raise the temperature at a gradient of 2 °C / min to 140 - 160 °C for heat preservation reaction for 2 - 3 h, cool down and discharge to obtain the modified epoxy resin.

[0008] By adopting the above technical solutions, aromatic amine components with rigid structures and high heat resistance are effectively introduced, and 2-ethyl-4-methylimidazole is used as a curing accelerator to accelerate the cross-linking reaction, thereby obtaining a modified epoxy resin with excellent high-temperature resistance. Specifically, the diamino groups of 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl and the epoxy groups construct a three-dimensional cross-linking network through nucleophilic ring-opening reaction. The conjugated effect of the biphenyl rigid skeleton restricts the movement of molecular chains, enhancing the thermal stability, while the steric hindrance of 2,2'-dimethyl delays the reaction rate, ensuring the uniformity of cross-linking. 2-ethyl-4-methylimidazole catalyzes in stages - preferentially activating the preliminary reaction of epoxy-amine at the low-temperature stage and promoting the deep cross-linking of secondary amines and the π-π ordered stacking of biphenyl segments at the high-temperature stage. Vacuum decompression synchronously removes by-product water and small molecules. Gradient heating induces the orientation arrangement of biphenyl chains along the heat flow direction, forming phonon conduction channels through the overlap of conjugated electron clouds. Periodic cross-linking points reduce lattice vibration scattering, ultimately greatly improving the thermal conductivity of the material while enhancing the high-temperature resistance of the epoxy resin.

[0009] Optionally, the modified epoxy resin contains the following raw materials in parts by weight: 12-14 parts of epoxy resin, 8-10 parts of 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 0.05-1 parts of 2-ethyl-4-methylimidazole, and 1.5-2 parts of propylene glycol methyl ether.

[0010] Optionally, the hexagonal boron nitride is a nanosheet with an aspect ratio of ≥500, and the particle size of the spherical silicon dioxide is 0.2-0.5 μm.

[0011] By adopting the above technical scheme, h-BN nanosheets with an aspect ratio of ≥500 are oriented along the direction of heat flow through high in-plane thermal conductivity to form a continuous thermal conduction path, and the edge boron atoms form BO-Si covalent bonds with the silanol groups generated by the hydrolysis of the silane coupling agent, effectively reducing the interfacial thermal resistance; 0.2-0.5μm spherical silica suppresses phonon scattering by filling the gaps between h-BN sheets, and at the same time, the silanol groups on its surface bond with the acidic sites of silicic zeolite to construct a three-dimensional interpenetrating thermal conductive network of "h-BN sheets-silica balls-silicic zeolite", thereby improving the overall thermal conductivity of the material; the rigid spheres of silica also suppress the stacking of h-BN sheets through the pinning effect, and cooperate with the flexible segments of polymethylphenylsiloxane to release thermal stress, ultimately achieving the synergistic optimization of high thermal conductivity and high-temperature stability.

[0012] Optionally, the epoxy resin is a dicyclopentadiene phenol type epoxy resin.

[0013] By adopting the above technical scheme, the cage-like alicyclic structure of dicyclopentadiene produces significant steric hindrance through high bond angle tension, inhibits the disordered entanglement of molecular chains in the prepolymerization stage, promotes the formation of short-range ordered prepolymers, and provides a directional template for subsequent cross-linking; the strong electron donation effect of the phenol group significantly reduces the activation energy of the epoxy group, and has an amino reaction efficiency with 4,4'-diamino-2,2'-dimethylbiphenyl that is significantly higher than that of other types of epoxy resins; its conjugated electron cloud distribution also enhances the π-π interaction with the imidazole catalyst, accurately controls the cross-linking kinetics under gradient temperature increase, and ultimately achieves a comprehensive transcendence of glass transition temperature, dielectric properties and resistance to moisture and heat aging.

[0014] Optionally, the curing accelerator is 2-phenylimidazole.

[0015] By adopting the above technical scheme, the electron-withdrawing effect of the phenyl group enhances the acidity of the imidazole ring, which can efficiently induce epoxy-phenolic crosslinking. At the same time, the steric hindrance effect of the phenyl group delays the diffusion of the catalyst, avoids local explosion, and ensures the uniformity of curing. In addition, the phenyl structure and the phenyl side chain of polymethylphenylsiloxane produce π-π interaction, inhibiting the resin-siloxane phase separation and simultaneously improving the heat resistance and thermal conductivity of the material.

[0016] Optionally, 1.5 - 2.5 parts of antioxidant are further added to the raw materials. The antioxidant is obtained by compounding tris(2,4 - di - tert - butylphenyl) phosphite and pentaerythritol tetrakis[β - (3,5 - di - tert - butyl - 4 - hydroxyphenyl) propionate] in a mass ratio of 1.5 - 2:1.

[0017] By adopting the above - mentioned technical solution, when the electronic device continuously operates at high temperature, the epoxy resin is prone to oxidation reaction, resulting in material deterioration and affecting the service life of the material. Therefore, an antioxidant is added to improve the antioxidant performance of the material through synergistic effect. Specifically, tris(2,4 - di - tert - butylphenyl) phosphite is good at capturing and decomposing the generated peroxides to prevent further oxidation reactions; while pentaerythritol tetrakis[β - (3,5 - di - tert - butyl - 4 - hydroxyphenyl) propionate] stabilizes free radicals by providing hydrogen atoms to interrupt the autoxidation chain reaction. This combination not only enhances the durability of the encapsulation material itself, but also produces a synergistic effect with the modified epoxy resin and other fillers in the system, jointly improving the thermal stability and environmental adaptability of the whole formulation, ensuring reliable protection for high - performance electronic devices under various conditions.

[0018] In a second aspect, the present application provides a preparation method of a high - performance electronic encapsulant, adopting the following technical solution: A preparation method of a high - performance electronic encapsulant, comprising the following steps: S1. Ultrasonically treat hexagonal boron nitride and part of the silane coupling agent in ethanol and then dry to obtain pretreated hexagonal boron nitride; ball - mill and mix spherical silica and another part of the silane coupling agent in acetone, and dry for standby to obtain pretreated spherical silica; S2. Heat the modified epoxy resin and polymethylphenylsiloxane to 60 - 70 °C, mix and stir evenly, then successively add the pretreated hexagonal boron nitride, spherical silica, and zeolite, perform high - shear dispersion, and synchronously evacuate and defoam to obtain a mixture; S3. Add the phenolic amine curing agent and the curing accelerator to the mixture obtained in S2, stir, react, dry, and cure to obtain the encapsulant.

[0019] In summary, the present application has the following beneficial effects: 1. The present application provides excellent mechanical properties through the combination of the modified epoxy resin and polymethylphenylsiloxane, and further enhances the thermal stability through the use of the phenolic amine curing agent and the curing accelerator. The addition of highly efficient heat - conducting fillers and the silane coupling agent enables the material to have good heat - conducting performance while maintaining good mechanical strength.

[0020] 2. In this application, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl is preferably used to modify epoxy resin. Through the steric hindrance effect and the directional cross-linking strategy, a highly regular three-dimensional network is formed, significantly improving the high-temperature resistance and thermal stability of the material, and breaking through the performance attenuation bottleneck of the traditional epoxy resin system in high-temperature environments.

[0021] 3. This application uses hexagonal boron nitride nanosheets with a high aspect ratio and spherical silica. Through their synergistic effect, a three-dimensional interpenetrating thermal conduction network is formed through interfacial chemical bonding and physical filling, realizing the directional optimization of the heat flow path, effectively suppressing phonon scattering. At the same time, combined with the flexible regulation of polymethylphenylsiloxane, both the thermal conduction efficiency and the thermal stress release ability are taken into account. Detailed implementation manners

[0022] The following further elaborates on this application in conjunction with examples.

[0023] For those not specifying specific conditions in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0024] Hexagonal boron nitride was purchased from Funik Superhard Materials Co., Ltd., with an aspect ratio of 500; spherical nano-silica was purchased from Ruijiang Metal Materials Co., Ltd. in Qinghe County, with a particle size of 0.2 - 0.5 μm; dicyclopentadiene phenol type epoxy resin was purchased from Shenzhen Huinya New Materials Technology Co., Ltd., model HY-1572, with an epoxy equivalent of 250 - 290; bisphenol A type epoxy resin was purchased from Wanqing Chemical Technology Co., Ltd., with an epoxy equivalent of 180 - 190; Preparation examples of raw materials and / or intermediates Preparation example 1 A modified epoxy resin, the preparation of which includes the following steps: Mix 12 kg of dicyclopentadiene phenol type epoxy resin with 9 kg of 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, and then heat them in an oil bath to 80 °C and stir and react at 300 rpm for 50 min to form a prepolymer; dissolve 0.05 kg of 2-ethyl-4-methylimidazole in 1.5 kg of propylene glycol methyl ether, and uniformly drop it into the prepolymer within 30 min. At the same time, vacuum depressurize to -0.06 MPa to remove the solvent. After the dropping is completed, raise the temperature to 150 °C at a gradient of 2 °C / min and keep it warm for 2 - 3 h, then cool to room temperature and discharge to obtain the modified epoxy resin.

[0025] Preparation example 2 A modified epoxy resin, the preparation of which includes the following steps: 14 kg of dicyclopentadiene phenol type epoxy resin and 8 kg of 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl were mixed and heated in an oil bath to 70 °C, and stirred at 300 rpm for 60 min to form a prepolymer; 1 kg of 2-ethyl-4-methylimidazole was dissolved in 2 kg of propylene glycol methyl ether, and was uniformly dropped into the prepolymer within 30 min. At the same time, the solvent was removed by vacuum decompression to -0.06 MPa. After the dropping was completed, the temperature was raised to 140 °C at a gradient of 2 °C / min and kept for reaction for 3 h, and then cooled to room temperature for discharging to obtain a modified epoxy resin.

[0026] Preparation Example 3 A modified epoxy resin, the preparation thereof comprises the following steps: 13 kg of dicyclopentadiene phenol type epoxy resin and 10 kg of 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl were mixed and heated in an oil bath to 90 °C, and stirred at 300 rpm for 40 min to form a prepolymer; 0.065 kg of 2-ethyl-4-methylimidazole was dissolved in 1.65 kg of propylene glycol methyl ether, and was uniformly dropped into the prepolymer within 30 min. At the same time, the solvent was removed by vacuum decompression to -0.06 MPa. After the dropping was completed, the temperature was raised to 160 °C at a gradient of 2 °C / min and kept for reaction for 2 h, and then cooled to room temperature for discharging to obtain a modified epoxy resin.

[0027] Preparation Example 4 A modified epoxy resin, which is different from Preparation Example 1 in that the epoxy resin used in this preparation example is bisphenol A type epoxy resin. Examples

[0028] Example 1 A high-performance electronic encapsulant, the preparation thereof comprises the following steps: S1. 6 kg of hexagonal boron nitride and 0.2 kg of silane coupling agent KH550 were put into ethanol and ultrasonically treated at 40 KHz for 1 h, and then dried at 80 °C to obtain pretreated hexagonal boron nitride; 3 kg of spherical silica and 0.3 kg of silane coupling agent KH550 were ball-milled and mixed in acetone at 300 rpm for 30 min, and then dried at 60 °C to obtain pretreated spherical silica; S2. 11 kg of the modified epoxy resin prepared in Preparation Example 1 and 7 kg of polymethylphenylsiloxane were mixed and heated to 60 °C and stirred at a speed of 500 rpm for 10 min, and then pretreated hexagonal boron nitride, spherical silica and 4 kg of silicalite were added in sequence, and high-shear dispersion was carried out at 8000 rpm for 30 min, and at the same time, vacuum was pumped to -0.08 MPa for defoaming treatment to obtain a mixture; S3. Add 2 kg of T31 curing agent (phenolic amine curing agent) and 0.5 kg of 2-phenylimidazole (curing accelerator) to the mixture obtained in S2, stir and react, heat up to 150 °C, dry and cure for 2 h to obtain the encapsulant.

[0029] Example 2 A high-performance electronic encapsulant, the preparation includes the following steps: S1. Put 7 kg of hexagonal boron nitride and 0.5 kg of silane coupling agent KH550 into ethanol, ultrasonically treat at 40 KHz for 1 h, and then dry at 80 °C to obtain pretreated hexagonal boron nitride; take 2 kg of spherical silica and 0.5 kg of silane coupling agent KH550, ball mill and mix in acetone at 300 rpm for 30 min, and then dry at 60 °C to obtain pretreated spherical silica; S2. Mix 10 kg of the modified epoxy resin prepared in Preparation Example 2 and 8 kg of polymethylphenylsiloxane, heat to 65 °C, stir at a speed of 500 rpm for 10 min, then successively add the pretreated hexagonal boron nitride, spherical silica, and 3 kg of silicalite, disperse at 8000 rpm by high shear for 30 min, and simultaneously perform vacuum pumping -0.08 MPa degassing treatment to obtain a mixture; S3. Add 1 kg of T31 curing agent (phenolic amine curing agent) and 1 kg of 2-phenylimidazole (curing accelerator) to the mixture obtained in S2, stir and react, heat up to 150 °C, dry and cure for 2 h to obtain the encapsulant.

[0030] Example 3 A high-performance electronic encapsulant, the preparation includes the following steps: S1. Put 5 kg of hexagonal boron nitride and 1 kg of silane coupling agent KH550 into ethanol, ultrasonically treat at 40 KHz for 1 h, and then dry at 80 °C to obtain pretreated hexagonal boron nitride; take 4 kg of spherical silica and 0.65 kg of silane coupling agent KH550, ball mill and mix in acetone at 300 rpm for 30 min, and then dry at 60 °C to obtain pretreated spherical silica; S2. Mix 12 kg of the modified epoxy resin prepared in Preparation Example 3 and 6 kg of polymethylphenylsiloxane, heat to 70 °C, stir at a speed of 500 rpm for 10 min, then successively add the pretreated hexagonal boron nitride, spherical silica, and 5 kg of silicalite, disperse at 8000 rpm by high shear for 30 min, and simultaneously perform vacuum pumping -0.08 MPa degassing treatment to obtain a mixture; S3. Add 3 kg of T31 curing agent (phenolic amine curing agent) and 0.65 kg of 2-phenylimidazole (curing accelerator) to the mixture obtained in S2, stir and react, heat up to 150 °C, dry and cure for 2 h to obtain the encapsulant.

[0031] Example 4 A high-performance electronic encapsulant, which is different from that in Example 1 in that the modified epoxy resin used in this example is obtained from Preparation Example 4.

[0032] Example 5 A high-performance electronic encapsulant, which is different from that in Example 1 in that the curing accelerator used in this example is 2-ethyl-4-methylimidazole.

[0033] Example 6 A high-performance electronic encapsulant, which is different from that in Example 1 in that 1.5 kg of antioxidant is further added in this example. The antioxidant is obtained by compounding tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] in a mass ratio of 1.5:1. The specific preparation includes the following steps: S1. Put 6 kg of hexagonal boron nitride and 0.2 kg of silane coupling agent KH550 into ethanol and ultrasonically treat them at 40 KHz for 1 h, and then dry them at 80 °C to obtain pretreated hexagonal boron nitride; take 3 kg of spherical silica and 0.3 kg of silane coupling agent KH550 and ball-mill and mix them in acetone at 300 rpm for 30 min, and then dry them at 60 °C to obtain pretreated spherical silica; S2. Mix 11 kg of the modified epoxy resin prepared in Preparation Example 1 and 7 kg of polymethylphenylsiloxane, heat them to 60 °C and stir them at a speed of 500 rpm for 10 min, and then successively add the pretreated hexagonal boron nitride, spherical silica, 4 kg of silicalite and 1.5 kg of antioxidant, and perform high-shear dispersion at 8000 rpm for 30 min, and synchronously perform vacuum degassing treatment at -0.08 MPa to obtain a mixture; S3. Add 2 kg of T31 curing agent (phenolic amine curing agent) and 0.5 kg of 2-phenylimidazole (curing accelerator) to the mixture obtained in S2, stir and react, raise the temperature to 150 °C, dry and cure for 2 h to obtain the encapsulant.

[0034] Example 7 A high-performance electronic encapsulant, which is different from that in Example 6 in that 2 kg of antioxidant is added in this example. The antioxidant is obtained by compounding tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] in a mass ratio of 2:1.

[0035] Example 8 A high-performance electronic encapsulant, which is different from that of Example 6 in that 2.5 kg of antioxidant is added in this example, and it is obtained by compounding tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] in a mass ratio of 2:1.

[0036] Example 9 A high-performance electronic encapsulant, which is different from that of Example 6 in that 1.5 kg of tris(2,4-di-tert-butylphenyl) phosphite is added as an antioxidant in this example.

[0037] Example 10 A high-performance electronic encapsulant, which is different from that of Example 6 in that 1.5 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is added in this example.

[0038] Example 11 A high-performance electronic encapsulant, which is different from that of Example 6 in that the antioxidant added in this example is dilauryl thiodipropionate.

[0039] Comparative Example Comparative Example 1 A high-performance electronic encapsulant, which is different from that of Example 1 in that unmodified dicyclopentadiene phenol type epoxy resin is used in this comparative example.

[0040] Comparative Example 2 A high-performance electronic encapsulant, which is different from that of Example 1 in that polymethylphenylsiloxane is not added in this comparative example.

[0041] Comparative Example 3 A high-performance electronic encapsulant, which is different from that of Example 1 in that the curing agent added in this comparative example is phthalic anhydride.

[0042] Comparative Example 4 A high-performance electronic encapsulant, which is different from that of Example 1 in that hexagonal boron nitride is not added in this comparative example.

[0043] Comparative Example 5 A high-performance electronic encapsulant, which is different from that of Example 1 in that spherical silica is not added in this comparative example.

[0044] Performance Detection Test Detection Method / Test Method The prepared electronic encapsulants are used to encapsulate microelectronic components respectively, with a thickness of 0.5 mm, cured at 150 °C for 2 h, and their various performances are tested; Thermal conductivity detection: The prepared electronic encapsulant was tested according to the steady-state heat flow method described in ASTM D5470-17; Tensile strength: The tensile strength of the electronic encapsulant was tested according to the relevant test methods in GB / T 1040.1-2018; High-temperature resistance performance detection: The encapsulated microelectronic components were placed in a liquid constant-temperature oil bath and stayed at 200 ± 5 °C for 100 h, then taken out to observe whether there were cracks or powdering phenomena on the encapsulation layer; Coefficient of thermal expansion: The coefficient of thermal expansion of the material was tested according to the relevant methods of a thermomechanical analyzer in ASTM E831-19. The smaller the coefficient of thermal expansion, the better its thermal stability.

[0045] Table 1 Test and detection results Combined with Examples 1-3 and Comparative Example 1 and Table 1, it can be seen that the experimental data of Examples 1-3 are all better than those of Comparative Example 1, indicating that further modification of epoxy resin can improve the high-temperature resistance of the material. The rigid structure introduced by the modification significantly improves the thermal stability of the crosslinked network by restricting the movement of molecular chains, thereby improving the high-temperature resistance performance of the material.

[0046] Combined with Examples 1-3 and Comparative Example 2 and Table 1, it can be seen that the experimental data of Examples 1-3 are all better than those of Comparative Example 2. The lack of polymethylphenylsiloxane will lead to insufficient flexibility and thermal stress release ability of the system. At the same time, due to the lack of π-π interaction between phenyl and resin, the interfacial compatibility decreases, exacerbating the risk of phase separation and resulting in a decline in various properties of the material.

[0047] Combined with Examples 1-3 and Comparative Example 3 and Table 1, it can be seen that the experimental data of Examples 1-3 are all better than those of Comparative Example 3, indicating that the selection of phenolic amine curing agent has high reaction adaptability with the modified epoxy resin, and its amino active sites can accurately match the alicyclic epoxy groups to form a dense and low-defect three-dimensional crosslinked network.

[0048] Combined with Examples 1-3 and Comparative Examples 3-4 and Table 1, it can be seen that the experimental data of Examples 1-3 are all better than those of Comparative Examples 3-4, indicating that hexagonal boron nitride nanosheets can have good synergistic effects with spherical silica to form a three-dimensional interpenetrating thermal conduction network. At the same time, combined with the flexible regulation of polymethylphenylsiloxane, the thermal conductivity and high-temperature resistance performance of the material are improved.

[0049] Combining Example 1 and Example 4 and referring to Table 1, it can be seen that all the experimental data of Example 1 are better than those of Example 4, indicating that the type of epoxy resin affects the final properties of the material. Selecting dicyclopentadienyl phenol type epoxy resin, the alicyclic rigid backbone and phenol group act synergistically, and the molecular chain orientation stability can still be maintained at high temperatures, improving its high temperature resistance performance.

[0050] Combining Example 1 and Example 5 and referring to Table 1, it can be seen that all the experimental data of Example 1 are better than those of Example 5, indicating that selecting 2-phenylimidazole as the curing accelerator has a better synergistic effect with the other materials in the raw materials, has a better curing promotion effect, and helps to improve the high temperature resistance and thermal conductivity of the material.

[0051] Combining Example 1 and Examples 6 - 8 and referring to Table 1, it can be seen that all the experimental data of Examples 6 - 8 are better than those of Example 1, indicating that the addition of antioxidants, especially the antioxidant compounded by tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], greatly improves the stability of the material at high temperatures through synergistic cooperation; comparing Example 6 with Examples 9 - 11, all the experimental data of Example 6 are better than those of Examples 9 - 11, indicating that selecting a single antioxidant or other types of antioxidants has a poor improvement effect. The antioxidant compounded by the two in proportion avoids the interfacial enrichment caused by the saturation effect of a single antioxidant and has a better performance improvement effect.

[0052] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A high-performance electronic encapsulation material, characterized in that: The composition comprises the following raw materials in parts by weight: 10-12 parts of modified epoxy resin, 6-8 parts of polymethylphenylsiloxane, 1-3 parts of phenolic amine curing agent, 2-4 parts of spherical silica, 0.5-1 parts of silane coupling agent, 3-5 parts of silica zeolite, 5-7 parts of hexagonal boron nitride, 0.5-1 parts of curing accelerator, and 2-4 parts of propylene glycol methyl ether.

2. A high-performance electronic encapsulation material according to claim 1, characterized in that: The modified epoxy resin is prepared by the following steps: The epoxy resin and 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl are mixed and heated in an oil bath to 70-90°C and stirred for reaction for 40-60 minutes to form a prepolymer; 2-ethyl-4-methylimidazole is dissolved in propylene glycol methyl ether and added dropwise to the prepolymer within 30 minutes, and vacuum pressure reduction is performed at the same time. After the addition is completed, the temperature is increased to 140-160°C at a gradient of 2°C / min and kept for reaction for 2-3 hours, and the temperature is reduced to obtain a modified epoxy resin.

3. A high-performance electronic encapsulation material according to claim 1, characterized in that: The modified epoxy resin comprises the following raw materials in parts by weight: 12-14 parts of epoxy resin, 8-10 parts of 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 0.05-1 parts of 2-ethyl-4-methylimidazole, and 1.5-2 parts of propylene glycol methyl ether.

4. The high-performance electronic encapsulation material according to claim 1, characterized in that: The hexagonal boron nitride is a nanosheet with an aspect ratio of ≥500, and the particle size of the spherical silicon dioxide is 0.2-0.5 μm.

5. The high-performance electronic encapsulation material according to claim 2, characterized in that: The epoxy resin is a dicyclopentadiene phenol type epoxy resin.

6. The high-performance electronic encapsulation material according to claim 1, characterized in that: The curing accelerator is 2-phenylimidazole.

7. The high-performance electronic encapsulation material according to claim 1, characterized in that: 1.5-2.5 parts of an antioxidant are also added to the raw materials. The antioxidant is prepared by compounding tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate at a mass ratio of 1.5-2:

1.

8. A method for preparing a high-performance electronic encapsulation material according to any one of claims 1 to 7, characterized in that: The steps include: S1. The hexagonal boron nitride and part of the silane coupling agent are ultrasonically treated in ethanol and then dried to obtain pretreated hexagonal boron nitride; spherical silica and another part of the silane coupling agent are ball-milled and mixed in acetone, and dried for standby use to obtain pretreated spherical silica; S2. The modified epoxy resin and polymethylphenylsiloxane are heated to 60-70 ° C and mixed and stirred uniformly, and then the pretreated hexagonal boron nitride, spherical silica, and silica zeolite are added in sequence, high shear dispersion, and vacuum degassing is performed simultaneously to obtain a mixture; S3. Add the phenolic amine curing agent and the curing accelerator to the mixture obtained in S2, stir, react, dry and solidify to obtain the encapsulating material.

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