Epoxy composition with high thermal conductivity and low moisture absorption rate and preparation method thereof

Abstract

The invention relates to an epoxy composition with high thermal conductivity and low moisture absorption rate. The epoxy composition comprises the following components in parts by mass: 13.0-20.0 parts of main chain symmetric epoxy resin, 6.0-11.0 parts of a curing agent, 2.0-5.0 parts of an active ester compound and 0.3-1.5 parts of a curing accelerator, 1.0 to 3.5 parts of a toughening agent; 0.3 to 0.7 part of an initiator; the flame-retardant epoxy resin composition disclosed by the invention has the advantages that the main chain symmetric epoxy resin can form an oriented chain structure in a curing process, has a molecular chain with a relatively high continuous length, tends to adopt a more relaxed and stretched state, provides a relatively long heat-conducting channel for phonon heat transfer, and has the characteristics that the flame-retardant epoxy resin composition can be used for heat transfer of phonons, so that the flame-retardant epoxy resin composition can be used for heat transfer of the phonons, and the flame-retardant epoxy resin composition can be used for heat transfer of the phonons. According to the present invention, dibenzoyl peroxide is introduced as an initiator, such that a double-bond-containing material is subjected to a polymerization cross-linking reaction so as to form a network interpenetrating structure, such that the moisture absorption rate of the system can be effectively reduced, and the reliability of the product can be effectively improved.

Description

Technical Field

[0001] The invention relates to the field of resin materials, and in particular to an epoxy composition with high thermal conductivity and low moisture absorption rate and a preparation method thereof. Background Art

[0002] Epoxy film is a polymer composite material composed mainly of epoxy resin and other materials. Epoxy film is often used as an encapsulation material in the chip packaging process to wrap the chip to form a protective layer, effectively preventing the chip from being damaged by the external environment.

[0003] However, with the improvement of chip manufacturing process, the power of chips is also increasing, which means that more heat is generated when they are working, requiring epoxy film to take on more heat conduction and heat dissipation functions. If the heat cannot be dissipated in time, it will affect the working stability of the chip. The moisture absorption rate of traditional epoxy film is high. In a humid working environment, the chip will easily cause corrosion and short circuits in the chip gap, and device delamination and fracture during high-temperature reflow soldering, affecting the electrical performance and long-term reliability of the chip. Moreover, with the rapid development of advanced packaging, such as wafer-level packaging, 2.5D / 3D stacked packaging, etc., the moisture absorption rate of the epoxy film used is required to be less than 1%. Therefore, it is of great significance to develop epoxy films with high thermal conductivity and low moisture absorption.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention discloses an epoxy composition with high thermal conductivity and low moisture absorption rate and a preparation method thereof.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A high thermal conductivity and low moisture absorption epoxy composition, characterized in that it comprises the following components, counted by mass: 13.0 to 20.0 parts of a main chain symmetrical epoxy resin, 6.0 to 11.0 parts of a curing agent, 2.0 to 5.0 parts of an active ester compound, 0.3 to 1.5 parts of a curing accelerator; 1.0 to 3.5 parts of a toughening agent; 0.3 to 0.7 parts of an initiator; 50.0 to 72.0 parts of a thermally conductive filler, 4.0 to 13.0 parts of a solvent, 1.1 to 1.8 parts of a coupling agent, 0.4 to 1.4 parts of a release agent, and 0.5 to 2.0 parts of a flame retardant.

[0008] Furthermore, the main chain symmetrical epoxy resin includes:

[0009] N,N,N,N,-Tetracyclyl-4,4-diaminodiphenylmethane, its structural formula 1: (Formula 1);

[0010] XYLOK phenolic epoxy resin, whose structural formula 2:

[0011] (Formula 2);

[0012] Phenol-biphenyl type epoxy resin, whose structural formula 3:

[0013] (Formula 3);

[0014] Tetramethyl-biphenyl type epoxy resin, whose structural formula 4: (Formula 4).

[0015] Furthermore, the toughening agent is a toughening agent containing double bonds, and the toughening agent containing double bonds is prepared by compounding one of CTBN or ATBN and the epoxy resin PB3600 containing double bonds, and the initiator is benzoyl peroxide.

[0016] Furthermore, the curing agent includes one of phenolic curing agents, dicyandiamide curing agents and imidazole curing agents.

[0017] Furthermore, the active ester compound is a dicyclopentadiene type active ester compound or a naphthalene type active ester compound.

[0018] Furthermore, the curing accelerator is one of DMP-30, dimethylbenzylamine and 2-ethyl-4-methylimidazole.

[0019] Furthermore, the heat-conducting filler includes two or more of spherical boron nitride, silicon carbide whiskers, spherical aluminum nitride or spherical aluminum oxide. The D50 range of the spherical boron nitride is 30 - 100 μm, the diameter range of the silicon carbide whiskers is 0.1 - 5 μm, the length is 10 - 150 μm, the D50 range of the spherical aluminum nitride is 10 - 80 μm, and the D50 range of the spherical aluminum oxide is 10 - 70 μm.

[0020] Furthermore, the solvent includes at least one of tripropylene glycol monomethyl ether, butyl acetate and ethylene glycol phenyl ether.

[0021] Furthermore, the coupling agent is a silane coupling agent; the release agent is one or a combination of carnauba wax and stearic acid wax; the flame retardant is at least one of nitrogen-containing flame retardants, organophosphorus flame retardants or antimony trioxide, and the nitrogen-containing flame retardants include melamine and melamine cyanurate.

[0022] A preparation method of a high heat-conducting and low moisture-absorption epoxy composition, comprising the following steps:

[0023] Step S1: Put the main-chain symmetric epoxy resin, solvent, active ester compound, and toughening agent according to the designed weight into a stirring kettle. Control the temperature in the stirring kettle at 60 - 90°C, the stirring time for 1 - 4 h, and the stirring speed at 2000 - 3000 rpm to obtain mixture A.

[0024] Step S2: Put the thermal conductive filler, curing agent, curing accelerator, initiator, flame retardant, coupling agent, and release agent into the stirring kettle, and stir and mix them with mixture A under normal temperature conditions. Control the stirring speed at 1500 - 2000 rpm and the stirring time for 1 - 3 h to obtain mixture B.

[0025] Step S3: Coating mixture B on the release film by means of a scraper coating method, then sending it into an oven for drying and forming. The temperature range of the oven is 80 - 120°C, and the film feeding speed in the oven is 1 - 2 m / s. Finally, wind up the obtained product.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. The main-chain symmetric epoxy resin will form an oriented chain structure during the curing process, and has molecular chains with a relatively high persistence length, tending to adopt a more relaxed and extended state, providing a longer heat conduction channel for phonon heat transfer, thereby forming more heat conduction paths, reducing the thermal resistance, being beneficial to the effective transfer of heat, and ultimately improving the thermal conductivity of the epoxy film.

[0028] 2. Benzoyl peroxide is introduced into the system as an initiator to cause the polymerization cross-linking reaction of CTBN, ATBN, and the double-bond-containing epoxy resin PB3600. Its molecular chains penetrate the entire system to form a dense network island structure. The internal structure of the cured system is dense, which can effectively reduce the moisture absorption rate, thermal expansion coefficient, and curing shrinkage rate of the system, preventing warping during the operation of the chip and affecting the reliability performance of the product.

[0029] 3. Adding the thermal conductive filler to the system can form an effective heat conduction channel inside the resin, enabling heat to be transferred more quickly from the high-temperature area to the low-temperature area, thereby improving the overall thermal conductivity of the epoxy resin.

[0030] 4. The functional groups in the silane coupling agent can undergo chemical reactions with the functional groups in the system to form stable chemical bonds. The formation of these chemical bonds can increase the cross-linking points in the resin system, thereby increasing the cross-linking density, effectively improving the thermal conductivity and moisture absorption of the system. The silane coupling agent can act as a "bridge" to improve the compatibility between the filler and the epoxy resin matrix, reduce interface defects, and improve the overall performance of the composite material. Description of the Drawings

[0031] Figure 1Schematic diagram of steps for a high thermal conductivity and low moisture absorption epoxy composition and its preparation method. Detailed implementation manners

[0032] The following combines with the attached drawings to illustrate the detailed implementation manners of the present invention.

[0033] Example 1:

[0034] A high thermal conductivity and low moisture absorption epoxy composition, including components counted by mass parts: 14 parts of phenol-biphenyl type epoxy resin, 7.5 parts of phenolic curing agent SH4064, 2.3 parts of dicyclopentadiene type active ester compound, 0.5 part of curing accelerator DMP-30; the toughening agent is made by compounding CTBN and epoxy resin PB3600 containing double bonds, and it is 2.0 parts; 0.6 part of initiator benzoyl peroxide; 23 parts of spherical boron nitride as thermal conductive filler (D50 = 80um), 11 parts of silicon carbide whiskers (diameter 5um, length 100um), 30.4 parts of spherical aluminum nitride (D50 = 30um), 6.0 parts of a mixed solution of tripropylene glycol monomethyl ether, butyl acetate and ethylene glycol phenyl ether as solvent, 1.2 parts of coupling agent KBM-4803, 1 part of mold release agent carnauba wax, 1.3 parts of flame retardant melamine cyanurate.

[0035] Wherein

[0036] Phenol-biphenyl type epoxy resin, its structural formula 3:

[0037] (Formula 3);

[0038] The preparation method of the high thermal conductivity and low moisture absorption epoxy composition, as Figure 1 shown, includes the following steps:

[0039] Step S1, put the main chain symmetric epoxy resin, solvent, active ester compound, and toughening agent according to the designed weight into a stirring kettle, control the temperature in the stirring kettle at 60 - 90°C, control the stirring time for 1 - 4h, and control the stirring speed at 2000 - 3000rpm to obtain mixture A.

[0040] Step S2, put the thermal conductive filler, curing agent, curing accelerator, initiator, flame retardant, coupling agent and mold release agent into the stirring kettle, and carry out stirring and mixing with mixture A under normal temperature conditions, control the stirring speed at 1500 - 2000rpm, and control the stirring time for 1 - 3h to obtain mixture B.

[0041] Step S3, use the doctor blade coating method to coat mixture B on the release film, then send it into an oven for drying and forming, the oven temperature range is 80 - 120°C, the film feeding speed in the oven is 1 - 2m / s, and finally wind up the obtained product.

[0042] Embodiment 2:

[0043] The difference from Example 1 is:

[0044] A high thermal conductivity and low moisture absorption epoxy composition comprises the following components, counted by mass: 19 parts of phenol biphenyl epoxy resin, 9 parts of phenolic curing agent SH4064, 4 parts of dicyclopentadiene active ester compound, 1 part of curing accelerator DMP-30; 3.0 parts of toughening agent prepared by compounding CTBN and double-bond epoxy resin PB3600; 0.5 parts of initiator dibenzoyl peroxide; 19.5 parts of thermal conductive filler spherical boron nitride (D50=30um), 9.5 parts of silicon carbide whisker (diameter 1um, length 150um), 26 parts of spherical aluminum nitride (D50=12um), 5.0 parts of solvent tripropylene glycol monomethyl ether, butyl acetate and ethylene glycol phenyl ether mixed solution, 1.2 parts of coupling agent KBM-4803, 1 part of demoulding agent carnauba wax, and 1.3 parts of flame retardant melamine cyanurate.

[0045] Example 2 was prepared using the same process and parameters as Example 1.

[0046] Embodiment 3:

[0047] The difference from Example 1 is:

[0048] A high thermal conductivity and low moisture absorption epoxy composition, comprising the following components by mass: 13 parts of phenol biphenyl epoxy resin, 6 parts of phenolic curing agent SH4064, 2 parts of dicyclopentadiene active ester compound, 4 parts of curing accelerator DMP-300; 0.5 parts of toughening agent, which is a compound of CTBN and double bond-containing epoxy resin PB3600; 0.3 parts of initiator dibenzoyl peroxide; thermal conductive filler Materials: 24.5 parts of spherical boron nitride (D50=90um), 12 parts of silicon carbide whiskers (diameter 0.5um, length 100um), 33.5 parts of spherical aluminum nitride (D50=80um), 5.6 parts of a mixture of tripropylene glycol monomethyl ether, butyl acetate and ethylene glycol phenyl ether, 1.1 parts of a coupling agent KBM-4803, 0.6 parts of a release agent carnauba wax, and 0.5 parts of a flame retardant melamine cyanurate.

[0049] Example 3 uses the same materials as Example 1 and is prepared using the same process and parameters.

[0050] Embodiment 4:

[0051] The difference from Example 1 is:

[0052] The epoxy resin is N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane.

[0053] N,N,N,N,-Tetraglycidyl-4,4-diaminodiphenylmethane, whose structural formula is 1: (Formula 1).

[0054] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0055] Example 5:

[0056] The difference from Example 1 is that:

[0057] The epoxy resin is a mixture of tetramethylbiphenyl type epoxy resin and XYLOK phenolic epoxy resin.

[0058] Among them, for XYLOK phenolic epoxy resin, its structural formula is 2: (Formula 2);

[0059] For tetramethylbiphenyl type epoxy resin, its structural formula is 4:

[0060]

[0061] (Formula 4).

[0062] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0063] Example 6:

[0064] The difference from Example 1 is that:

[0065] The curing agent is dicyandiamide curing agent, specifically Ecure14.

[0066] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0067] Example 7:

[0068] The difference from Example 1 is that:

[0069] The curing agent is imidazole curing agent, specifically Accelerator XB 5730.

[0070] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0071] Example 8:

[0072] The difference from Example 1 is that:

[0073] The active ester compound is naphthalene type active ester compound.

[0074] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0075] Example 9:

[0076] The difference from Example 1 is as follows:

[0077] The curing accelerator is selected as dimethylbenzylamine.

[0078] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0079] Example 10:

[0080] The difference from Example 1 is as follows:

[0081] The curing accelerators are selected as dimethylbenzylamine and 2-ethyl-4-methylimidazole.

[0082] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0083] Example 11:

[0084] The difference from Example 1 is as follows:

[0085] The toughening agent is a toughening agent containing double bonds, which is prepared by compounding ATBN and an epoxy resin PB3600 containing double bonds.

[0086] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0087] Example 12:

[0088] The difference from Example 1 is as follows:

[0089] The thermal conductive filler is a mixture of silicon carbide whiskers (diameter 0.5 μm, length 50 μm) and spherical alumina (D50 = 50 μm), totaling 64.4 parts.

[0090] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0091] Example 13:

[0092] The difference from Example 1 is as follows:

[0093] The thermal conductive filler is a mixture of silicon carbide whiskers (diameter 0.5 μm, length 50 μm) and spherical boron nitride (D50 = 50 μm), totaling 64.4 parts.

[0094] The properties of the obtained sample are close to those of the sample prepared in Example 1.

[0095] Example 14:

[0096] The difference from Example 1 is as follows:

[0097] The heat-conducting filler selects 23 parts of spherical boron nitride (D50 = 80um), 11 parts of silicon carbide whiskers (diameter 5um, length 100um), and 30.4 parts of spherical aluminum oxide (D50 = 40um).

[0098] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0099] Example 15:

[0100] The difference from Example 1 is that:

[0101] The heat-conducting filler selects a composition of spherical boron nitride (D50 = 50um) and silicon carbide whiskers (diameter 3um, length 80um), totaling 64.4 parts.

[0102] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0103] Example 16:

[0104] The difference from Example 1 is that:

[0105] The heat-conducting filler selects a composition of spherical boron nitride (D50 = 50um) and spherical aluminum nitride (D50 = 50um), totaling 64.4 parts.

[0106] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0107] Example 17:

[0108] The difference from Example 1 is that:

[0109] The heat-conducting filler selects a composition of spherical boron nitride (D50 = 50um) and spherical aluminum oxide (D50 = 50um), totaling 64.4 parts.

[0110] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0111] Example 18:

[0112] The difference from Example 1 is that:

[0113] The heat-conducting filler selects a composition of silicon carbide whiskers (diameter 3um, length 80um) and spherical aluminum nitride (D50 = 50um), totaling 64.4 parts.

[0114] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0115] Example 19:

[0116] The difference from Example 1 is that:

[0117] The coupling agent specifically selects X-12-1172ES.

[0118] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0119] Example 20:

[0120] The difference from Example 1 is as follows:

[0121] The coupling agent is specifically selected as X-12-1056ES.

[0122] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0123] Example 21:

[0124] The difference from Example 1 is as follows:

[0125] The mold release agent is selected as carnauba wax and stearic acid wax.

[0126] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0127] Example 22:

[0128] The difference from Example 1 is as follows:

[0129] The flame retardant is selected as an organophosphorus flame retardant.

[0130] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0131] Example 23:

[0132] The difference from Example 1 is as follows:

[0133] The flame retardant is selected as a combination of antimony trioxide and melamine.

[0134] The performance of the obtained sample is close to that of the sample prepared in Example 1.

[0135] Comparative Example 1:

[0136] The main-chain symmetric epoxy resin used in Example 1 is replaced with o-cresol novolac epoxy resin.

[0137] Comparative Example 2:

[0138] Benzoyl peroxide is not used in Example 1.

[0139] Comparative Example 3:

[0140] The toughening agent used in Example 1 is replaced with a core-shell structured polymer toughening agent MX154. Comprehensive performance test of epoxy adhesive film:

[0141] Experimental detection standard:

[0142] The glass transition temperature and coefficient of thermal expansion are tested with reference to GB / T 38108-2006. The thermal conductivity is tested with reference to ASTM D5470-2012.

[0143] The water absorption rate is tested with reference to GB / T 1462-2005.

[0144] The breakdown strength difference is tested with reference to GB / T 1408.1-2006.

[0145] Sampling: Randomly select sample film adhesives from Examples 1 to 24 and Comparative Examples 1 to 3 for testing.

[0146]

[0147]

[0148]

[0149] Analysis of experimental results:

[0150] In Examples 1 to 23, the thermal conductivity of the film adhesive is between 6.0 and 7.0 (w / m·K), indicating that using main-chain symmetric epoxy resin and combining with different specifications of thermal conductive fillers to form a close packing model endows the epoxy film adhesive with excellent thermal conductivity. The glass transition temperature of the film adhesive is above 160 °C, with good thermal stability, and it can ensure the structural form temperature of the film adhesive for a long time under high-temperature working conditions. The breakdown strength of the film adhesive is ≥10 (kV / mm), with excellent insulation performance. The coefficient of thermal expansion a1 of the film adhesive below the glass transition temperature Tg is ≤16, indicating that under the heating environment below the glass transition temperature Tg of the film adhesive, the internal structure changes relatively little, reflecting good structural stability; the coefficient of thermal expansion a2 of the film adhesive above the glass transition temperature Tg is ≤32.4, and during the heating deformation process, the film adhesive does not show a drastic volume change, and the internal structure of the film adhesive maintains good stability. The moisture absorption rate of the film adhesive is about 0.10. The effect of the chemical composition and molecular structure of the film adhesive on the moisture absorption rate macroscopically proves that the internal network of the formed resin system interpenetrates and the structure is dense; the shrinkage rate of the film adhesive is about 0.010 to 0.04. During the process of the resin changing from liquid to solid, there is no excessive internal stress aggregation. If the shrinkage rate is too large and a large amount of internal stress is generated, it may cause defects such as cracks in the film adhesive.

[0151] It can be seen from the data in the table that compared with Example 1, in Comparative Example 1, using o-cresol novolac epoxy resin to replace symmetric epoxy resin results in a significant decrease in thermal conductivity and thermal performance.

[0152] Comparing Comparative Example 2 with Example 1, without adding benzoyl peroxide, the polymerization cross-linking reaction of the double-bond polymer chains in the system cannot occur, a dense network structure cannot be formed, and the heat conduction channels are reduced, which has a great impact on the water absorption rate, thermal conductivity, and thermal performance.

[0153] Comparing Comparative Example 3 with Example 1, using a core-shell structure polymer toughener to replace the double-bond-containing toughener also has an impact on the performance of the system, especially the water absorption rate and thermal performance, and the comparative example is greatly affected.

[0154] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0155] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A high thermal conductivity and low moisture absorption epoxy composition, characterized in that: The invention comprises the following components counted by mass: 13.0 to 20.0 parts of main chain symmetrical epoxy resin, 6.0 to 11.0 parts of curing agent, 2.0 to 5.0 parts of active ester compound, 0.3 to 1.5 parts of curing accelerator, 1.0 to 3.5 parts of toughening agent, 0.3 to 0.7 parts of initiator, 50.0 to 72.0 parts of thermal conductive filler, 4.0 to 13.0 parts of solvent, 1.1 to 1.8 parts of coupling agent, 0.4 to 1.4 parts of release agent and 0.5 to 2.0 parts of flame retardant.

2. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The main chain symmetrical epoxy resin includes: N,N,N,N,-Tetracyclyl-4,4-diaminodiphenylmethane, its structural formula 1: (Formula 1); XYLOK phenolic epoxy resin, its structural formula 2: (Formula 2); Phenol biphenyl type epoxy resin, its structural formula 3: (Formula 3); Tetramethylbiphenyl epoxy resin, its structural formula 4: (Formula 4).

3. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The toughening agent is a toughening agent containing double bonds, which is prepared by compounding one of CTBN or ATBN and double-bond epoxy resin PB3600; the initiator is dibenzoyl peroxide.

4. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The curing agent includes one of a phenolic curing agent, a dicyandiamide curing agent and an imidazole curing agent.

5. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The active ester compound is a dicyclopentadiene type active ester compound or a naphthalene type active ester compound.

6. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The curing accelerator is one of DMP-30, dimethylbenzylamine and 2-ethyl-4-methylimidazole.

7. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The thermal conductive filler includes two or more of spherical boron nitride, silicon carbide whiskers, spherical aluminum nitride or spherical aluminum oxide. The D50 range of the spherical boron nitride is 30 to 100 μm, the diameter range of the silicon carbide whiskers is 0.1 to 5 μm, and the length is 10 to 150 μm. The D50 range of the spherical aluminum nitride is 10 to 80 μm, and the D50 range of the spherical aluminum oxide is 10 to 70 μm.

8. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The solvent includes at least one of tripropylene glycol monomethyl ether, butyl acetate, and ethylene glycol phenyl ether.

9. The high thermal conductivity and low moisture absorption epoxy composition according to claim 1, characterized in that: The coupling agent is a silane coupling agent; the release agent is one of carnauba wax and stearic acid wax or a combination of the two; the flame retardant is at least one of a nitrogen-containing flame retardant, an organic phosphorus flame retardant or antimony trioxide, and the nitrogen-containing flame retardant includes melamine and melamine cyanurate.

10. A method for preparing the epoxy composition with high thermal conductivity and low moisture absorption rate according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, adding a main chain symmetrical epoxy resin, a solvent, an active ester compound, and a toughening agent according to a designed weight into a stirring tank, controlling the temperature in the stirring tank at 60 to 90° C., the stirring time at 1 to 4 hours, and the stirring speed at 2000 to 3000 rpm to obtain a mixture A; Step S2, putting the thermal conductive filler, curing agent, curing accelerator, initiator, flame retardant, coupling agent and release agent into a stirring kettle, and stirring and mixing with the mixture A at room temperature, controlling the stirring speed to 1500-2000 rpm, and controlling the stirring time to 1-3 hours, to obtain a mixture B; Step S3, coating the mixture B on the release film by a doctor blade coating method, and then sending it into an oven for drying and forming. The oven temperature range is 80-120° C., and the film feeding speed in the oven is 1-2 m / s. Finally, the obtained product is rolled up.

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