High thermal conductive epoxy resin composite for resistor package and preparation method thereof

Abstract

The application provides a high-thermal-conductivity epoxy resin composite for resistor packaging and a preparation method thereof, and relates to the technical field of packaging materials.The composite comprises an epoxy resin, a filler, a curing agent and an accelerator;the mass ratio of the epoxy resin, the filler, the curing agent and the accelerator is (20-40):(60-80):(20-30):(0.1-0.3);the filler is 1,5 pentanediol modified micrometer alumina;the preparation method mainly comprises 1,5 pentanediol modified micrometer alumina filler preparation, epoxy resin composite blend preparation and epoxy resin composite defoaming and curing treatment.The epoxy resin composite prepared by the application has the characteristics of low viscosity and high filling, has excellent thermal conductivity and excellent process performance, realizes the synergistic improvement of the comprehensive performance of the resistor packaging material, and guarantees the working stability of the resistor.

Description

Technical Field

[0001] This invention relates to the technical field of resistor packaging materials, specifically to a high thermal conductivity epoxy resin composite material for resistor packaging and its preparation method. Background Technology

[0002] As electronic devices become increasingly integrated, the heat generated inside them tends to accumulate, leading to higher operating temperatures. Under prolonged exposure to high temperatures, the circuit connections and packaging materials of these devices are prone to failure, severely impacting their lifespan. This places higher demands on the heat resistance and thermal conductivity of the packaging materials.

[0003] Heat-resistant epoxy resin has broad application prospects in the field of resistor packaging. However, the high content of aromatic rings in the molecular structure of heat-resistant epoxy resin results in a higher viscosity compared to ordinary epoxy resin, making it difficult to achieve high filling of inorganic fillers at low viscosity. This leads to low thermal conductivity of epoxy composite materials, which limits the further application of heat-resistant epoxy composite materials in the field of resistor packaging. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a high thermal conductivity epoxy resin composite material for resistor packaging and its preparation method, which solves the problem that existing resistor packaging materials are difficult to achieve high filling at low viscosity, resulting in low thermal conductivity.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A high thermal conductivity epoxy resin composite material for resistor encapsulation includes epoxy resin, filler, curing agent and accelerator; the mass ratio of the epoxy resin, the filler, the curing agent and the accelerator is (20-40):(60-80):(20-30):(0.1-0.3); the filler is 1,5-pentanediol modified micron-sized alumina.

[0009] Preferably, the mass ratio of the epoxy resin, the 1,5-pentanediol-modified micronized alumina, the curing agent, and the accelerator is 30:70:25:0.2.

[0010] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0011] S1. Preparation of 1,5-pentanediol-modified micron-sized alumina filler

[0012] S1.1. Mix unmodified micronized alumina with deionized water and stir magnetically to react and obtain a hydroxylated micronized alumina solution;

[0013] S1.2. The above hydroxylated micronized alumina solution is then filtered and dried to obtain hydroxylated micronized alumina;

[0014] S1.3. The above-mentioned hydroxylated micronized alumina is mixed with 1,5-pentanediol and reacted using magnetic stirring to obtain a 1,5-pentanediol-modified micronized alumina solution;

[0015] S1.4. The above 1,5-pentanediol-modified micronized alumina solution is then filtered and dried to obtain 1,5-pentanediol-modified micronized alumina.

[0016] S2. 1,5-pentanediol-modified micronized alumina filler is blended with epoxy resin, then a curing agent is added and stirred, followed by an accelerator and stirred to obtain a mixture;

[0017] S3. Pour the above mixture into a mold that has been coated with release agent and preheated, then place it in an oven for vacuum degassing and curing, and then demold and remove it to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0018] Preferably, the particle size of the micron-sized alumina in S1.1 is 1 to 20 microns.

[0019] Preferably, in step S1.1, mixing unmodified micron-sized alumina with deionized water includes:

[0020] Add 70g of micron-sized alumina to a beaker containing 70ml of deionized water.

[0021] Preferably, in step S1.2, the hydroxylated micronized alumina is mixed with 1,5-pentanediol, comprising:

[0022] Add 70g of hydroxylated micronized alumina to 70g of 1,5-pentanediol.

[0023] Preferably, the reaction conditions in S1.1 are: a high-temperature and high-pressure reaction at 180°C for 10 hours.

[0024] Preferably, the reaction conditions in S1.3 are: a high-temperature and high-pressure reaction at 245°C for 6 hours.

[0025] Preferably, adding a curing agent and stirring in step S2 includes: adding a curing agent and stirring under vacuum at 100°C for 1 hour.

[0026] Preferably, the addition of an accelerator and stirring in step S2 includes: adding the accelerator and continuing to stir under vacuum at 100°C for 10 minutes.

[0027] Preferably, during the S3 curing process, the curing is first carried out at 140°C for 4 hours, then at 180°C for 10 hours, and finally at 220°C for 3 hours.

[0028] (III) Beneficial Effects

[0029] This invention provides a high thermal conductivity epoxy resin composite material for resistor encapsulation and its preparation method. Compared with the prior art, it has the following advantages:

[0030] 1. By adding 1,5-pentanediol to modify micron-sized alumina, the wettability between the filler and epoxy resin is improved, thereby increasing the filler content at the same viscosity. This enhances the thermal conductivity of the epoxy resin composite material used for resistor encapsulation while also considering its processability, achieving a synergistic improvement in the overall performance of the resistor encapsulation material and ensuring the working stability of the resistor.

[0031] 2. Through two steps of high temperature and high pressure reaction, micron-sized alumina is first hydroxylated and then grafted with 1,5-pentanediol to obtain 1,5-pentanediol-modified micron-sized alumina. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This application provides a high thermal conductivity epoxy resin composite material for resistor packaging and its preparation method, which solves the problem that existing resistor packaging materials are difficult to achieve high filling at low viscosity, resulting in low thermal conductivity. It realizes a low viscosity high filling process, and the filling packaging material under this process has excellent thermal conductivity.

[0034] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0035] A high thermal conductivity epoxy resin composite material for resistor packaging, comprising epoxy resin, 1,5-pentanediol-modified micron-sized alumina, curing agent, and accelerator;

[0036] The mass ratio of epoxy resin, 1,5-pentanediol-modified micronized alumina, curing agent, and accelerator is (20-40):(60-80):(20-30):(0.1-0.3).

[0037] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0038] S1. Preparation of 1,5-pentanediol-modified micron-sized alumina filler

[0039] S1.1. Mix unmodified micronized alumina with deionized water, stir magnetically, and react to obtain a hydroxylated micronized alumina solution;

[0040] S1.2. The above hydroxylated micronized alumina solution is then filtered and dried to obtain hydroxylated micronized alumina;

[0041] S1.3. The above-mentioned hydroxylated micronized alumina is mixed with 1,5-pentanediol and stirred magnetically to react, thereby obtaining a 1,5-pentanediol-modified micronized alumina solution;

[0042] S1.4. The above 1,5-pentanediol-modified micronized alumina solution is then filtered and dried to obtain 1,5-pentanediol-modified micronized alumina.

[0043] S2. 1,5-pentanediol-modified micronized alumina filler is blended with epoxy resin, then a curing agent is added and stirred, followed by an accelerator and stirred to obtain a mixture;

[0044] S3. Pour the above mixture into a mold that has been coated with release agent and preheated, then place it in an oven for vacuum degassing and curing, and then demold and remove it to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0045] The epoxy resin mentioned above is a bisphenol A type epoxy resin, and all other materials were purchased from the market.

[0046] Example 1:

[0047] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0048] S1. Preparation of 1,5-pentanediol-modified micron-sized alumina filler

[0049] S1.1. Add 70g of micronized alumina to a beaker containing 70ml of deionized water and stir magnetically at 25℃ for 30min. Then, place the mixture into a high-pressure reactor and react at 180℃ for 10h. After that, filter the hydroxylated micronized alumina solution for 30min and dry it at 80℃ for 24h to obtain hydroxylated micronized alumina.

[0050] S1.2. Add 70g of hydroxylated micronized alumina to 70g of 1,5-pentanediol and stir magnetically to ensure the 1,5-pentanediol fully impregnates the micronized alumina. Then place the mixture in a high-pressure reactor and react at 245℃ for 6 hours. Filter the 1,5-pentanediol-modified micronized alumina solution for 30 minutes. Dry the solution at 80℃ for 24 hours to obtain 1,5-pentanediol-modified micronized alumina.

[0051] S2. Melt 30g of epoxy resin at 120℃, then pour 70g of 1,5-pentanediol-modified micronized alumina into the molten epoxy resin and stir for 15min. Separately, melt 25g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the mixture of epoxy resin and filler, and stir under vacuum at 100℃ for 1h. Then, add 0.2g of N,N-dimethylbenzylamine and continue stirring under vacuum at 100℃ for 10min to obtain the final mixture.

[0052] S3. Pour the mixture into a mold that has been coated with silicone release agent and preheated, then place it in an oven for vacuum degassing for 15 minutes. Then cure it according to the curing procedure of first curing at 140℃ for 4 hours, then curing at 180℃ for 10 hours, and then curing at 220℃ for 3 hours. Finally, demold and remove it, and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0053] Example 2:

[0054] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0055] S1. Preparation of 1,5-pentanediol-modified micron-sized alumina filler

[0056] S1.1. Add 60g of micronized alumina to a beaker containing 60ml of deionized water and stir magnetically at 25℃ for 30min. Then, place the mixture into a high-pressure reactor and react at 180℃ for 9h. After that, filter the hydroxylated micronized alumina solution for 30min and dry it at 80℃ for 24h to obtain hydroxylated micronized alumina.

[0057] S1.2. Add 60g of hydroxylated micronized alumina to 60g of 1,5-pentanediol and stir magnetically to ensure the 1,5-pentanediol fully impregnates the micronized alumina. Then place the mixture in a high-pressure reactor and react at 240℃ for 5 hours. Filter the 1,5-pentanediol-modified micronized alumina solution for 30 minutes. Dry the solution at 80℃ for 24 hours to obtain 1,5-pentanediol-modified micronized alumina.

[0058] S2. Melt 30g of epoxy resin at 120℃, then pour 60g of 1,5-pentanediol-modified micronized alumina into the molten epoxy resin and stir for 15min. Separately, melt 25g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the mixture of epoxy resin and filler, and stir under vacuum at 100℃ for 1h. Then, add 0.2g of N,N-dimethylbenzylamine and continue stirring under vacuum at 100℃ for 10min to obtain the final mixture.

[0059] S3. Pour the mixture into a mold that has been coated with silicone release agent and preheated, then place it in an oven for vacuum degassing for 15 minutes. Then cure it according to the curing procedure of first curing at 130℃ for 4 hours, then curing at 180℃ for 9 hours, and then curing at 210℃ for 4 hours. Finally, demold and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0060] Example 3:

[0061] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0062] S1. Preparation of 1,5-pentanediol-modified micron-sized alumina filler

[0063] S1.1. Add 70g of micronized alumina to a beaker containing 60ml of deionized water and stir magnetically at 25℃ for 30min. Then, place the mixture into a high-pressure reactor and react at 180℃ for 11h. After that, filter the hydroxylated micronized alumina solution for 30min and dry it at 80℃ for 23h to obtain hydroxylated micronized alumina.

[0064] S1.2. Add 70g of hydroxylated micronized alumina to 60g of 1,5-pentanediol and stir magnetically to ensure the 1,5-pentanediol fully impregnates the micronized alumina. Then place the mixture in a high-pressure reactor and react at 230℃ for 7 hours. Filter the 1,5-pentanediol-modified micronized alumina solution for 30 minutes and dry it at 80℃ for 23 hours to obtain 1,5-pentanediol-modified micronized alumina.

[0065] S2. Melt 40g of epoxy resin at 120℃, then pour 70g of 1,5-pentanediol-modified micronized alumina into the molten epoxy resin and stir for 10min. Separately, melt 30g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the mixture of epoxy resin and filler, and stir under vacuum at 100℃ for 0.5h. Then, add 0.1g of N,N-dimethylbenzylamine and continue stirring under vacuum at 100℃ for 15min to obtain the final mixture.

[0066] S3. Pour the mixture into a mold that has been coated with silicone release agent and preheated, then place it in an oven for vacuum degassing for 10 minutes. Then cure it according to the curing procedure of first curing at 150℃ for 4 hours, then curing at 170℃ for 10 hours, and then curing at 210℃ for 3 hours. Finally, demold and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0067] Example 4:

[0068] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0069] S1. Preparation of 1,5-pentanediol-modified micron-sized alumina filler

[0070] S1.1. Add 60g of micronized alumina to a beaker containing 80ml of deionized water and stir magnetically at 25℃ for 20min. Then, place the mixture into a high-pressure reactor and react at 170℃ for 10h. After that, filter the hydroxylated micronized alumina solution for 20min and dry it at 70℃ for 25h to obtain hydroxylated micronized alumina.

[0071] S1.2. Add 60g of hydroxylated micronized alumina to 80g of 1,5-pentanediol and stir magnetically to ensure the 1,5-pentanediol fully impregnates the micronized alumina. Then place the mixture in a high-pressure reactor and react at 250℃ for 5 hours. Filter the 1,5-pentanediol-modified micronized alumina solution for 40 minutes. Dry the solution at 80℃ for 24 hours to obtain 1,5-pentanediol-modified micronized alumina.

[0072] S2. Melt 40g of epoxy resin at 120℃, then pour 60g of 1,5-pentanediol-modified micronized alumina into the molten epoxy resin and stir for 15min. Separately, melt 20g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the mixture of epoxy resin and filler, and stir under vacuum at 100℃ for 1.5h. Then, add 0.2g of N,N-dimethylbenzylamine and continue stirring under vacuum at 90℃ for 10min to obtain the final mixture.

[0073] S3. Pour the mixture into a mold that has been coated with silicone release agent and preheated, then place it in an oven for vacuum degassing for 20 minutes. Then cure it according to the curing procedure of first curing at 150℃ for 5 hours, then curing at 190℃ for 9 hours, and then curing at 230℃ for 2 hours. Finally, demold and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0074] Example 5:

[0075] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0076] S1. Preparation of 1,5-pentanediol-modified micron-sized alumina filler

[0077] S1.1. Add 80g of micronized alumina to a beaker containing 60ml of deionized water and stir magnetically at 25℃ for 40min. Then, place the mixture into a high-pressure reactor and react at 190℃ for 11h. After that, filter the hydroxylated micronized alumina solution for 40min and dry it at 90℃ for 25h to obtain hydroxylated micronized alumina.

[0078] S1.2. Add 80g of hydroxylated micronized alumina to 60g of 1,5-pentanediol and stir magnetically to ensure the 1,5-pentanediol fully impregnates the micronized alumina. Then place the mixture in a high-pressure reactor and react at 250℃ for 7 hours. Filter the 1,5-pentanediol-modified micronized alumina solution for 40 minutes and dry it at 90℃ for 25 hours to obtain 1,5-pentanediol-modified micronized alumina.

[0079] S2. Melt 40g of epoxy resin at 120℃, then pour 80g of 1,5-pentanediol-modified micronized alumina into the molten epoxy resin and stir for 20min. Separately, melt 25g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the mixture of epoxy resin and filler, and stir under vacuum at 100℃ for 1.5h. Then, add 0.1g of N,N-dimethylbenzylamine and continue stirring under vacuum at 110℃ for 15min to obtain the final mixture.

[0080] S3. Pour the mixture into a mold that has been coated with release agent and preheated, then place it in an oven for vacuum degassing for 20 minutes. Then cure it according to the curing procedure of first curing at 150℃ for 5 hours, then curing at 190℃ for 11 hours, and then curing at 230℃ for 4 hours. Finally, demold and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0081] Comparative Example 1

[0082] The only difference from Example 1 is that no filler was added. Specifically:

[0083] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0084] S1. Melt 30g of epoxy resin at 120℃. Separately, melt 25g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the epoxy resin and stir under vacuum at 100℃ for 1 hour. Then, add 0.2g of N,N-dimethylbenzylamine and continue stirring under vacuum at 100℃ for 10 minutes to obtain the mixture.

[0085] S2. Pour the mixture into a mold that has been coated with silicone release agent and preheated, then place it in an oven for vacuum degassing for 15 minutes. Then cure it according to the curing procedure of first curing at 140℃ for 4 hours, then curing at 180℃ for 10 hours, and then curing at 220℃ for 3 hours. Finally, demold and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0086] Comparative Example 2

[0087] The only difference from Example 1 is that the micron-sized alumina remains unmodified. Specifically:

[0088] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0089] S1. Melt 30g of epoxy resin at 120℃, then pour 70g of micron-sized alumina into the molten epoxy resin and stir for 15min. Separately, melt 25g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the mixture of epoxy resin and filler, and stir under vacuum at 100℃ for 1h. Then, add 0.2g of N,N-dimethylbenzylamine and continue stirring under vacuum at 100℃ for 10min to obtain the final mixture.

[0090] S2. Pour the mixture into a mold that has been coated with silicone release agent and preheated, then place it in an oven for vacuum degassing for 15 minutes. Then cure it according to the curing procedure of first curing at 140℃ for 4 hours, then curing at 180℃ for 10 hours, and then curing at 220℃ for 3 hours. Finally, demold and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0091] Comparative Example 3

[0092] The only difference from Example 1 is that the micron-sized alumina is modified with KH550. Details are as follows:

[0093] A method for preparing a high thermal conductivity epoxy resin composite material for resistor packaging specifically includes the following steps:

[0094] S1. Melt 30g of epoxy resin at 120℃, then pour 70g of KH550 modified micronized alumina into the molten epoxy resin and stir for 15min. Separately, melt 25g of anhydride curing agent with an anhydride value of 0.534mol / 100g at 100℃, then pour the fully melted anhydride curing agent into the mixture of epoxy resin and filler, and stir under vacuum at 100℃ for 1h. Then, add 0.2g of N,N-dimethylbenzylamine and continue stirring under vacuum at 100℃ for 10min to obtain the final mixture.

[0095] S2. Pour the mixture into a mold that has been coated with silicone release agent and preheated, then place it in an oven for vacuum degassing for 15 minutes. Then cure it according to the curing procedure of first curing at 140℃ for 4 hours, then curing at 180℃ for 10 hours, and then curing at 220℃ for 3 hours. Finally, demold and let it stand at room temperature to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

[0096] Experimental Data and Analysis

[0097] The filler viscosity and thermal conductivity of the final product of Examples 1-5 and Comparative Examples 1-3 were tested, and the results are recorded in Table 1 below:

[0098] Table 1 - Filler viscosity and thermal conductivity data of composite materials in the examples and comparative examples

[0099]

[0100]

[0101] By comparing the data of Example 1 and Comparative Examples 1, 2, and 3 in the table above, it can be seen that the 1,5-pentanediol-modified micronized alumina of the present invention has a significantly better effect on improving the thermal conductivity of epoxy resin composite materials for resistor packaging than the unmodified micronized alumina without filler and the micronized alumina modified with silane coupling agent. Furthermore, the 1,5-pentanediol-modified micronized alumina used in the present invention has a lower viscosity, which can achieve low-viscosity, high-filling process operation.

[0102] In summary, compared with existing technologies, it has the following beneficial effects:

[0103] 1. By adding 1,5-pentanediol to modify micron-sized alumina, the wettability between the filler and epoxy resin is improved, thereby increasing the filler content at the same viscosity. This enhances the thermal conductivity of the epoxy resin composite material used for resistor encapsulation while also considering its processability, achieving a synergistic improvement in the overall performance of the resistor encapsulation material and ensuring the working stability of the resistor.

[0104] 2. Through two steps of high temperature and high pressure reaction, micron-sized alumina is first hydroxylated and then grafted with 1,5-pentanediol to obtain 1,5-pentanediol-modified micron-sized alumina.

[0105] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0106] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high thermal conductivity epoxy resin composite material for resistor encapsulation, characterized in that, The product comprises epoxy resin, filler, curing agent, and accelerator; the mass ratio of the epoxy resin, filler, curing agent, and accelerator is (20-40):(60-80):(20-30):(0.1-0.3); the filler is 1,5-pentanediol-modified micron-sized alumina. The preparation method of the 1,5-pentanediol modified micron-sized alumina includes: Unmodified micronized alumina was mixed with deionized water, stirred and reacted to obtain a hydroxylated micronized alumina solution. The above hydroxylated micronized alumina solution is then filtered and dried to obtain hydroxylated micronized alumina. The above-mentioned hydroxylated micronized alumina was mixed with 1,5-pentanediol and stirred to obtain a 1,5-pentanediol-modified micronized alumina solution. The above 1,5-pentanediol-modified micronized alumina solution was then filtered and dried to obtain 1,5-pentanediol-modified micronized alumina.

2. The high thermal conductivity epoxy resin composite material for resistor encapsulation as described in claim 1, characterized in that, The mass ratio of the epoxy resin, the 1,5-pentanediol-modified micronized alumina, the curing agent, and the accelerator is 30:70:25:0.

2.

3. A method for preparing a high thermal conductivity epoxy resin composite material for resistor encapsulation, characterized in that, Specifically, the following steps are included: S1. Preparation of 1,5-pentanediol modified micron-sized alumina filler; S2. 1,5-pentanediol-modified micronized alumina filler is blended with epoxy resin, then a curing agent is added and stirred, followed by the addition of an accelerator and stirring to obtain a mixture; the mass ratio of the epoxy resin, the 1,5-pentanediol-modified micronized alumina filler, the curing agent and the accelerator is (20-40):(60-80):(20-30):(0.1-0.3); S3. Degas and cure the above mixture to obtain a heat-resistant epoxy resin composite material for resistor encapsulation; The specific method for preparing the 1,5-pentanediol-modified micron-sized alumina filler in S1 is as follows: S1.

1. Mix unmodified micronized alumina with deionized water, stir and mix, and react to obtain a hydroxylated micronized alumina solution; S1.

2. The above hydroxylated micronized alumina solution is then filtered and dried to obtain hydroxylated micronized alumina; S1.

3. The above-mentioned hydroxylated micronized alumina is mixed with 1,5-pentanediol and stirred to react, resulting in a 1,5-pentanediol-modified micronized alumina solution; S1.

4. The above 1,5-pentanediol-modified micronized alumina solution is then filtered and dried to obtain 1,5-pentanediol-modified micronized alumina.

4. The method for preparing the high thermal conductivity epoxy resin composite material for resistor encapsulation as described in claim 3, characterized in that, In step S1.1, mixing unmodified micronized alumina with deionized water includes: Add 70g of micron-sized alumina to a beaker containing 70ml of deionized water; In step S1.2, the hydroxylated micronized alumina is mixed with 1,5-pentanediol, comprising: Add 70g of hydroxylated micronized alumina to 70g of 1,5-pentanediol.

5. The method for preparing the high thermal conductivity epoxy resin composite material for resistor encapsulation as described in claim 3, characterized in that, The reaction conditions in S1.1 are: a high-temperature and high-pressure reaction at 180°C for 10 hours; The reaction conditions in S1.3 are: a high-temperature and high-pressure reaction at 245°C for 6 hours.

6. The method for preparing the high thermal conductivity epoxy resin composite material for resistor encapsulation as described in claim 3, characterized in that, The addition of a curing agent and stirring in step S2 includes: adding the curing agent and stirring under vacuum at 100°C for 1 hour.

7. The method for preparing the high thermal conductivity epoxy resin composite material for resistor encapsulation as described in claim 3, characterized in that, The process of adding an accelerator and stirring in step S2 includes: adding the accelerator and continuing to stir under vacuum at 100°C for 10 minutes.

8. The method for preparing the high thermal conductivity epoxy resin composite material for resistor encapsulation as described in claim 3, characterized in that, In step S3, the mixture is degassed and cured to obtain the high thermal conductivity epoxy resin composite material for resistor encapsulation, comprising: The mixture is poured into a mold that has been coated with release agent and preheated, then placed in an oven for vacuum degassing and curing, and then demolded to obtain a high thermal conductivity epoxy resin composite material for resistor encapsulation.

9. The method for preparing the high thermal conductivity epoxy resin composite material for resistor encapsulation as described in claim 8, characterized in that, During the curing process, the material is first cured at 140°C for 4 hours, then cured at 180°C for 10 hours, and finally cured at 220°C for 3 hours.

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