Anti-settling heat-conducting laminated film as well as preparation method and application thereof

Abstract

The invention provides an anti-settling heat-conducting laminated film as well as a preparation method and application thereof. The anti-settling heat-conducting laminated film is prepared from the following components in parts by mass: 20-80 parts of matrix epoxy resin, 10-50 parts of heat-resistant epoxy resin, 1-50 parts of a curing agent, 0.1-3 parts of a curing accelerator and 400-800 parts of modified aluminum oxide, the preparation method comprises the following steps: performing surface hydroxylation on alumina powder, then performing functionalization, reacting the alumina powder with a long-chain organic molecule solution, and introducing long-chain organic molecules to the surface of alumina, so that the modified alumina is uniformly dispersed in an epoxy resin system, is not easy to settle and has good uniformity; meanwhile, the interface thermal resistance between an epoxy resin system and the filler can be reduced, and the thermal conductivity and the humidity and heat resistance of the laminated film are improved. The anti-settling heat-conducting film prepared by the invention has excellent flowability, uniformity and heat and humidity resistance as well as good heat conductivity, and can be applied to IC (integrated circuit) support plate packaging.

Description

Technical Field

[0001] The present invention belongs to the technical field of IC packaging, and particularly relates to an anti-settling thermal conductive laminated film, a preparation method thereof and an application thereof. Background Art

[0002] With the progress of technology, electronic devices will continue to develop towards high functionality and high integration. The heat generated by heat-generating components is greater. If it cannot be dissipated quickly, it will greatly affect the operating speed and service life of electronic products. The IC carrier board encapsulated by the traditional laminated film can no longer meet the usage requirements. The laminated film is in direct contact with the chip. Improving the thermal conductivity of the laminated film is beneficial to heat transfer and reduces the operating temperature of the electronic device. At present, the conventional method is to replace the filler with alumina, silicon nitride, silicon carbide, etc. with higher thermal conductivity on the basis of the original laminated film. Among them, alumina is widely used due to its advantages of low price and easy availability. However, the thermal conductivity of alumina is relatively low compared with thermal conductive fillers such as silicon nitride, and a higher filling amount is often required to achieve a higher thermal conductivity. When the filling ratio of alumina is relatively high, the settling problem of alumina is more prominent, resulting in a narrow process window of the slurry and poor uniformity of the thermal conductive laminated film, which limits its use.

[0003] Therefore, how to provide an anti-settling thermal conductive laminated film, by modifying the filler alumina and combining with an epoxy resin system, to improve the thermal conductivity, fluidity and uniformity of the laminated film, so as to be applicable to the field of IC carrier board packaging, is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0004] The purpose of the present invention is to provide an anti-settling thermal conductive laminated film, a preparation method thereof and an application thereof, so as to solve at least one of the above technical problems.

[0005] To achieve the above purpose, in the first aspect of the present invention, an anti-settling thermal conductive laminated film is provided. The anti-settling thermal conductive laminated film is composed of the following components in parts by mass: 20-80 parts of matrix epoxy resin, 10-50 parts of heat-resistant epoxy resin, 1-50 parts of curing agent, 0.1-3 parts of curing accelerator, and 400-800 parts of modified alumina; the matrix epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin and alicyclic epoxy resin, and the mass fraction of the bisphenol A epoxy resin is 40-45 parts; the heat-resistant epoxy resin includes at least one of dicyclopentadiene phenol epoxy resin, biphenyl type epoxy resin, naphthol epoxy resin and polyfunctional epoxy resin.

[0006] In the first aspect, the mass fraction of the matrix epoxy resin is 40-80 parts, the mass fraction of the heat-resistant epoxy resin is 15-45 parts, the mass fraction of the curing agent is 5-45 parts, the mass fraction of the curing accelerator is 1 part, and the modified alumina is 500-600 parts.

[0007] In the first aspect, the curing agent includes at least one of dicyandiamide and phenolic resin.

[0008] In the first aspect, the curing accelerator includes imidazole accelerators.

[0009] In the first aspect, the method for preparing the modified alumina includes the following steps: S1. Add a mixed solution of hydrogen peroxide and water with a mass ratio of 1:1 to alumina powder, stir and react at 60 - 90 °C, and obtain surface-hydroxylated alumina through filtration, drying, and crushing; S2. Add absolute ethanol to the surface-hydroxylated alumina, stir and react at 70 °C for 4 hours, then slowly dropwise add a silane coupling agent solution, react at room temperature for 2 hours, filter, wash, dry, and crush to obtain functionalized alumina; S3. Prepare a long-chain organic molecule solution; S4. Add the functionalized alumina to the long-chain organic molecule solution, stir and react at 80 - 130 °C for 1 - 4 hours, filter, dry, and crush to obtain modified alumina.

[0010] In the first aspect, in step S2, the silane coupling agent solution is prepared as follows: Add a silane coupling agent to a mixed solution of pure water and absolute ethanol with a mass ratio of 2:1, mix evenly, adjust the pH value to 4.0 with acetic acid, and perform ultrasonic dispersion for 10 minutes to obtain the silane coupling agent solution.

[0011] In the first aspect, in step S3, the preparation of the long-chain organic molecule solution specifically includes the following steps: Sequentially add a bifunctional epoxy resin and an aromatic amine epoxy curing agent to propylene glycol methyl ether acetate, and stir and react at 80 - 130 °C until the solution becomes clear to obtain the long-chain organic molecule solution.

[0012] In the first aspect, when the silane coupling agent is an epoxy group-containing coupling agent and the functionalized alumina in step S2 is surface epoxy group alumina, then the long-chain organic molecule solution in step S3 is a double-terminal amino long-chain organic molecule solution I, wherein the mass ratio of the bifunctional epoxy resin to the aromatic amine epoxy curing agent is 1:2 or 2:3 or 3:4 or 4:5; when the silane coupling agent is a primary amino group-containing coupling agent and the functionalized alumina in step S2 is surface primary amino alumina; then the long-chain organic molecule solution in step S3 is a double-terminal epoxy group long-chain organic molecule solution II, wherein the mass ratio of the bifunctional epoxy resin to the aromatic amine epoxy curing agent is 2:1 or 3:2 or 4:3 or 5:4.

[0013] In the second aspect of the present invention, a method for preparing an anti-settling and heat-conducting laminated film is provided. The preparation method includes: weighing 20-80 parts by mass of a matrix epoxy resin, 10-50 parts by mass of a heat-resistant epoxy resin, and 400-800 parts by mass of modified alumina in a planetary mixer according to the mass parts of the components of the anti-settling and heat-conducting laminated film described in the first aspect, adding a solvent, stirring at 100-130 °C for 0.5-3 hours, mixing evenly, cooling to room temperature to obtain a first slurry; adding 1-50 parts by mass of a curing agent and 0.1-3 parts by mass of a curing accelerator to the first slurry, stirring at room temperature for 20-60 minutes to obtain a uniformly mixed second slurry; uniformly coating the second slurry on a PET base film, drying it in an oven to remove the solvent, and removing the PET base film to obtain an anti-settling and heat-conducting laminated film with a thickness of 10-500 μm.

[0014] In the third aspect of the present invention, an application of the anti-settling and heat-conducting laminated film described in the first aspect in IC carrier board packaging is provided.

[0015] Beneficial effects: An anti-settling and heat-conducting laminated film provided by the present invention is composed of the following components by mass: 20-80 parts of a matrix epoxy resin, 10-50 parts of a heat-resistant epoxy resin, 1-50 parts of a curing agent, 0.1-3 parts of a curing accelerator, and 400-800 parts of modified alumina; the matrix epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin, and the mass parts of bisphenol A epoxy resin are 40-45 parts. Taking this as the matrix material, combined with the heat-resistant epoxy resin to provide the basic properties of the laminated film, and using the modified alumina as the filling material, the modified alumina can be evenly dispersed in the epoxy resin system, is not easy to settle, has good fluidity and uniformity, improves the thermal conductivity and heat and humidity resistance of the laminated film, and at the same time combines the curing agent and the curing accelerator to improve the storage validity period of the laminated film, making it meet the requirements of IC carrier board packaging. Description of the drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a flow chart of the preparation method of the modified alumina in the embodiment of the present invention. Detailed implementation manners

[0018] The present invention will be specifically described below in conjunction with specific embodiments and examples, and the advantages and various effects of the present invention will be presented more clearly thereby. Those skilled in the art should understand that these specific embodiments and examples are used to illustrate the present invention rather than limit the present invention.

[0019] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood to have the meanings as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as the general understanding of those skilled in the art to which the present invention pertains. In case of any contradiction, this specification shall prevail.

[0020] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in the present invention can be obtained through market purchase or by existing methods.

[0021] A sedimentation-proof and heat-conducting laminated film provided by the present application is composed of the following components in parts by mass: 20-80 parts of matrix epoxy resin, 10-50 parts of heat-resistant epoxy resin, 1-50 parts of curing agent, 0.1-3 parts of curing accelerator, and 400-800 parts of modified alumina; the matrix epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin, and the mass fraction of the bisphenol A epoxy resin is 40-45 parts; the heat-resistant epoxy resin includes at least one of dicyclopentadiene phenol epoxy resin, biphenyl-type epoxy resin, naphthol epoxy resin, and polyfunctional epoxy resin.

[0022] Specifically, a sedimentation-proof and heat-conducting laminated film provided by the present invention is composed of the following components in parts by mass: 20-80 parts of matrix epoxy resin, 10-50 parts of heat-resistant epoxy resin, 1-50 parts of curing agent, 0.1-3 parts of curing accelerator, and 400-800 parts of modified alumina; the matrix epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin, and the mass fraction of the bisphenol A epoxy resin is 40-45 parts. Taking this as the matrix material, and combining with the heat-resistant epoxy resin to provide the basic properties of the laminated film, and using the modified alumina as the filling material, so that the modified alumina can be evenly dispersed in the epoxy resin system, is not easy to settle, has good fluidity and uniformity, improves the thermal conductivity and heat and humidity resistance of the laminated film, and at the same time combines the curing agent and the curing accelerator to improve the storage validity period of the laminated film, making it meet the requirements of IC carrier board packaging.

[0023] In some possible embodiments, the mass fraction of the matrix epoxy resin is 40-80 parts, the mass fraction of the heat-resistant epoxy resin is 15-45 parts, the mass fraction of the curing agent is 5-45 parts, the mass fraction of the curing accelerator is 1 part, and the modified alumina is 500-600 parts.

[0024] Further, the matrix epoxy resin may be selected from bisphenol A epoxy resin or bisphenol F epoxy resin with an epoxy equivalent of 170 - 300, or linear phenolic epoxy resin with an epoxy equivalent of 120 - 150, or alicyclic epoxy resin with an epoxy equivalent of 100 - 300.

[0025] In some possible embodiments, the curing agent includes at least one of dicyandiamide and phenolic resin.

[0026] In the present application, the curing agent is a latent curing agent to improve the storage life of the laminated film. As a preferred solution, the curing agent may include dicyandiamide or phenolic resin.

[0027] In some possible embodiments, the curing accelerator includes imidazole accelerators.

[0028] In the present application, selecting imidazole accelerators can adjust the storage time, curing temperature, and curing speed of the laminated film.

[0029] In some possible embodiments, please refer to Figure 1 , the preparation method of the modified alumina includes the following steps: S1. Add a mixed solution of hydrogen peroxide and water with a mass ratio of 1:1 to alumina powder, stir and react at 60 - 90 °C, and obtain surface-hydroxylated alumina through filtration, drying, and crushing. S2. Add absolute ethanol to the surface-hydroxylated alumina, stir and react at 70 °C for 4 hours, then slowly dropwise add a silane coupling agent solution, react at room temperature for 2 hours, and obtain functionalized alumina through filtration, washing, drying, and crushing. S3. Prepare a long-chain organic molecule solution. S4. Add the functionalized alumina to the long-chain organic molecule solution, stir and react at 80 - 130 °C for 1 - 4 hours, filter, dry, and crush to obtain modified alumina.

[0030] By modifying conventional alumina powder, first surface-hydroxylating and then functionalizing the alumina powder to react with the long-chain organic molecule solution, long-chain organic molecules are introduced onto the alumina surface, so that the modified alumina can be evenly dispersed in the epoxy resin system, is not easy to settle, and has good uniformity; at the same time, the interfacial thermal resistance between the epoxy resin system and the filler can be reduced, and the thermal conductivity and moisture and heat resistance of the laminated film can be improved. In a specific embodiment, the conventional alumina powder may be spherical alumina with a particle size of 0.1 - 30 μm.

[0031] In some possible embodiments, in step S2, the silane coupling agent solution is prepared as follows: A silane coupling agent is added to a mixed solution of pure water and absolute ethanol with a mass ratio of 2:1. After mixing evenly, the pH value is adjusted to 4.0 with acetic acid, and ultrasonic dispersion is carried out for 10 minutes to obtain the silane coupling agent solution.

[0032] In some possible embodiments, in step S3, the preparation of the long-chain organic molecule solution specifically includes the following steps: A bifunctional epoxy resin and an aromatic amine epoxy curing agent are successively added to propylene glycol methyl ether acetate, and stirred and reacted at 80-130 °C until the solution becomes clear to obtain the long-chain organic molecule solution.

[0033] In some possible embodiments, when the silane coupling agent is an epoxy group-containing coupling agent and the functionalized alumina in step S2 is surface epoxy group alumina, the long-chain organic molecule solution in step S3 is a double-terminal amino long-chain organic molecule solution I, wherein the mass ratio of the bifunctional epoxy resin to the aromatic amine epoxy curing agent is 1:2 or 2:3 or 3:4 or 4:5; when the silane coupling agent is a primary amino group-containing coupling agent and the functionalized alumina in step S2 is surface primary amino alumina, the long-chain organic molecule solution in step S3 is a double-terminal epoxy group long-chain organic molecule solution II, wherein the mass ratio of the bifunctional epoxy resin to the aromatic amine epoxy curing agent is 2:1 or 3:2 or 4:3 or 5:4.

[0034] Specifically, by adjusting the ratio of the bifunctional epoxy resin to the aromatic amine epoxy curing agent, the end groups of the long-chain organic molecules are made to be epoxy groups or amino groups, and then the reaction activity of the surface epoxy groups or primary amine groups of the functionalized alumina is used to react with the long-chain organic molecules, thereby realizing grafting of organic molecules on the surface of alumina, reducing the interfacial thermal resistance with the epoxy resin system, and improving the thermal conductivity of the laminated film. The reaction formula of the bifunctional epoxy resin and the aromatic amine epoxy curing agent is as follows: ; wherein, A 1 is or , A 2 is or , A 3 is , and n is an integer, , through experiments, when, it is not conducive to heat transfer between the filler alumina.

[0035] The bifunctional epoxy resins preferably include bisphenol A epoxy resin and bisphenol F epoxy resin; the aromatic amine curing agents preferably include 4,4'-diaminodiphenylmethane (DDM) and 4,4'-diaminodiphenyl ether (DDE); the silane coupling agents preferably include γ-glycidoxypropyltrimethoxysilane (KH560), γ-glycidoxypropyltriethoxysilane (KH561), and γ-aminopropyltriethoxysilane (KH550).

[0036] Based on a general inventive concept, the present application also provides a method for preparing an anti-settling thermally conductive laminated film, and the preparation method includes: (1) Weigh 20 - 80 parts of matrix epoxy resin, 10 - 50 parts of heat-resistant epoxy resin, and 400 - 800 parts of modified alumina according to the mass parts of the components of the anti-settling thermally conductive laminated film described in the first aspect in a planetary mixer, add a solvent, stir at 100 - 130 °C for 0.5 - 3 hours, mix evenly, cool to room temperature, and obtain a first slurry; (2) Add 1 - 50 parts of a curing agent and 0.1 - 3 parts of a curing accelerator to the first slurry, stir at room temperature for 20 - 60 minutes, and obtain a second slurry with uniform mixing; (3) Uniformly coat the second slurry on a PET base film, place it in an oven for drying to remove the solvent, remove the PET base film, and obtain an anti-settling thermally conductive laminated film with a thickness of 10 - 500 μm.

[0037] Specifically, after the second slurry is uniformly coated on the PET base film and dried to remove the solvent, a PET base film can be laminated on the dried second slurry to form a laminated film product for easy storage and transportation. When in use, the PET base film can be torn off.

[0038] Based on a general inventive concept, the present application also provides an application of the anti-settling thermally conductive laminated film described in the first aspect in IC carrier board packaging.

[0039] The anti-settling thermally conductive laminated film provided by the present application can be applied to IC carrier board packaging. The laminated film is laminated on the IC carrier board by hot pressing, so that the laminated film can be completely laminated with the chip, transfer the heat generated by the chip outward, and thus extend the service life of the chip.

[0040] The following further elaborates the present application in combination with specific examples. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods without specific conditions noted in the following examples are generally determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0041] The specific raw materials used in the examples and comparative examples are as follows: Bisphenol A epoxy resin: CAS No.: 25068-38-6; Manufacturer: Nan Ya 128; Phenolic epoxy resin: Nan Ya NPCN-703; Dicyclopentadiene phenol epoxy resin: Changchun TaiLuck-TJ100; Biphenyl type epoxy resin: Tetramethylbiphenyl bisphenol A epoxy resin; Naphthol epoxy resin: Grade: NC-7300L; Manufacturer: Nippon Kayaku Co., Ltd.; Curing agent: Dicyandiamide: CAS No.: 461-58-5, Xinxi Metallurgical Chemical Industry; Curing agent: Phenolic resin: CAS No. 65733-76-8, Kolon KPH-F2004; Curing accelerator: Imidazole-based curing accelerator, Manufacturer: BASF 2E4MI, CAS No.: 931-36-2, Composition: 2-Ethyl-4-methylimidazole; Aluminum oxide powder: D50 particle size 2um; Manufacturer: DENKA Co., Ltd. DAW-01; Aromatic amine-based epoxy curing agent: Diaminodiphenylmethane: CAS No.: 101-77-9; Manufacturer: Shandong Xuchen Chemical Industry.

[0042] The specific preparation steps of the modified alumina used in the examples and comparative examples are as follows: (1) Hydroxylation of the alumina surface: Add a mixed solution of 100g hydrogen peroxide and 100g pure water to 1000g alumina powder, stir and react at 60°C for 4 hours, filter, dry, and crush to obtain surface-hydroxylated alumina; (2) Surface modification with silane coupling agent: Add 1000g of surface-hydroxylated alumina to anhydrous ethanol, stir and react at 70°C for 4 hours, slowly dropwise add the silane coupling agent solution, react at room temperature for 2 hours, filter, wash with anhydrous ethanol 5 times, dry, and crush to obtain surface-epoxy-group-modified alumina; Among them, the preparation steps of the silane coupling agent solution include: Add 10g of KH560 to a mixed solution of 20g of pure water and 10g of anhydrous ethanol, adjust the PH value to 4.0 with acetic acid, ultrasonicate for 10 minutes, and let stand for 1 hour; (3) Synthesis of long-chain organic molecules: Add bisphenol A epoxy resin and diaminodiphenylmethane in a mass ratio of 3:4 to the propylene glycol methyl ether acetate solvent, stir and react at 100°C until the solution is clear to obtain a solution of double-terminal amino long-chain organic molecules I; (4) Grafting on the alumina surface: Add the surface-epoxy-group-modified alumina obtained in (2) to the solution of double-terminal amino long-chain organic molecules I in (3), stir and react at 110°C for 2 hours to perform epoxy group capping treatment on the terminal amino groups of the organic macromolecules, and the reaction solution is obtained after filtration, drying, and crushing. Modified alumina.

[0043] The components of the raw materials in Examples 1-4 and Comparative Examples 1-6 in this application are shown in Table 1 according to their mass fractions: Table 1 Distribution ratio of each group of raw materials in the examples and comparative examples The anti-settling thermal conductive laminated films provided in Examples 1-4 and Comparative Examples 1-6 were subjected to performance tests, and the specific test process is as follows: 1. Slurry stability: Turbiscan multiple light scattering instrument is used for testing. The slurry needs to be degassed before testing. The test time is 6 hours, the cycle is 5 minutes / time, and the light intensity fluctuation value at different time periods is taken. ; 2. Glass transition temperature: tested using DMA dual cantilever mode, multi-strain method, and a heating rate of 5°C / min; 3. Rheological viscosity: Use a rheometer for testing, with a heating rate of 5°C / min and the rheological viscosity value at 100°C; 4. Thermal conductivity: Use hot wire method thermal conductivity meter for testing, test voltage 1.5v, test 5 samples and take the average value; 5. Copper bonding strength: The sample is made of two copper sheets overlapped and cured by thermal conductive film, and the bonding strength of the sample is tested using the tensile mode of an electronic universal material testing machine; 6. Bending strength: tested in three-point bending mode using an electronic universal material testing machine with a span of 36 mm; 7. Evaluation of moisture and heat resistance: Take an uncured laminated film sample with a size of 1cm×5cm and bond it to a copper sheet, then cure it, and then perform a high pressure cooking test (PCT) on the cured sample bonded to the copper sheet: PCT conditions: 121℃, relative humidity 100%RH; perform ultrasonic scanning on the sample every 24h; if delamination occurs between the laminated film and the copper sheet, record the corresponding test time; if no delamination occurs, continue the high pressure cooking test until 192h.

[0044] The test results are shown in Table 2 below: Table 2 Test results It can be seen from the above table that in Examples 1-4 and Comparative Examples 3-6, the modified alumina prepared in this application is used as filler, and the light intensity fluctuation value is is low and increases with time. The small increase in value indicates that using the modified alumina of the present application as a filler can prevent the settlement of the filler, and the prepared slurry has good uniformity, which can extend the slurry coating time, facilitate operation, and further improve the uniformity of the cured laminated film. When comparing the experimental data of Example 1 and Comparative Example 3, and Example 3 and Comparative Example 5, it shows that when the addition amount of the modified alumina is less than 500 parts by mass, the thermal conductivity of the laminated film is less than 2 W / m·k -1 , and the rheological viscosity and flexural strength of the laminated film both decrease, not meeting the requirements. When comparing the experimental data of Example 4 and Comparative Example 6, it shows that when the addition amount of the modified alumina is higher than 600 parts by mass, the thermal conductivity of the laminated film is higher than 2.36 W / m·k -1 , resulting in excessive thermal conductivity performance and an increase in rheological viscosity, which is not conducive to the coating of the slurry. Further, in Comparative Examples 1-2, modified alumina was not used, and the prepared laminated film was prone to delamination from the copper sheet during the autoclave test, that is, the reliability during the IC carrier board packaging process was low, increasing potential risks; at the same time, it also shows that the laminated film prepared with modified alumina has excellent moisture and heat resistance.

[0045] Finally, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0046] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0047] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. An anti-settling thermally conductive laminated film, characterized in that: The anti-settling thermal conductive laminated film is composed of the following components by mass: 20-80 parts of base epoxy resin, 10-50 parts of heat-resistant epoxy resin, 1-50 parts of curing agent, 0.1-3 parts of curing accelerator, and 400-800 parts of modified alumina; the modified alumina is a long-chain organic molecule grafted with a functionalized alumina, the long-chain organic molecule is a double-terminated amino long-chain organic molecule or a double-terminated epoxy long-chain organic molecule, and the functionalized alumina is a surface epoxy alumina or a surface primary amino alumina; The base epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin and alicyclic epoxy resin; The heat-resistant epoxy resin includes at least one of dicyclopentadiene phenol epoxy resin, biphenyl epoxy resin, naphthol epoxy resin and multifunctional epoxy resin.

2. The anti-settling thermally conductive laminated film according to claim 1, characterized in that: The mass fraction of the base epoxy resin is 40-80 parts, the mass fraction of the heat-resistant epoxy resin is 15-45 parts, the mass fraction of the curing agent is 5-45 parts, the mass fraction of the curing accelerator is 1 part, and the modified alumina is 500-600 parts; Wherein, the matrix epoxy resin is bisphenol A epoxy resin or is compounded from bisphenol A epoxy resin and novolac epoxy resin.

3. The anti-settling thermally conductive laminated film according to claim 2, characterized in that: The curing agent includes at least one of dicyandiamide and phenolic resin.

4. The anti-settling thermally conductive laminated film according to claim 3, characterized in that: The curing accelerator includes an imidazole accelerator.

5. The anti-settling thermally conductive laminated film according to any one of claims 1 to 4, characterized in that: The preparation method of the modified alumina comprises the following steps: S1. Add a mixed solution of hydrogen peroxide and water in a mass ratio of 1:1 to alumina powder, stir and react at 60-90° C., and obtain surface hydroxylated alumina by filtering, drying and crushing; S2, adding anhydrous ethanol to the surface hydroxylated alumina, stirring and reacting at 70° C. for 4 hours, slowly dropping a silane coupling agent solution, reacting at room temperature for 2 hours, filtering, washing, drying, and crushing to obtain functionalized alumina; S3, preparing a long-chain organic molecule solution; S4, adding the functionalized alumina to the long-chain organic molecule solution, stirring and reacting at 80-130° C. for 1-4 hours, filtering, drying, and crushing to obtain modified alumina.

6. The anti-settling thermally conductive laminated film according to claim 5, characterized in that: In step S2, the silane coupling agent solution is prepared by adding a silane coupling agent to a mixed solution of pure water and anhydrous ethanol in a mass ratio of 2:1, mixing evenly, adjusting the pH value to 4.0 with acetic acid, and ultrasonically dispersing for 10 minutes to obtain a silane coupling agent solution.

7. The anti-settling thermally conductive laminated film according to claim 6, characterized in that: In step S3, the preparation of the long-chain organic molecule solution specifically includes the following steps: adding a bifunctional epoxy resin and an aromatic amine epoxy curing agent to propylene glycol methyl ether acetate in sequence, and stirring the reaction at 80-130° C. until the solution becomes clear, to obtain a long-chain organic molecule solution.

8. The anti-settling thermally conductive laminated film according to claim 7, characterized in that: When the silane coupling agent is an epoxy-containing coupling agent, and the functionalized alumina in step S2 is surface epoxy-containing alumina, the long-chain organic molecule solution in step S3 is a double-terminated amino long-chain organic molecule solution I, wherein the mass ratio of the bifunctional epoxy resin to the aromatic amine epoxy curing agent is 1:2 or 2:3 or 3:4 or 4:5; When the silane coupling agent is a primary amino-containing coupling agent, the functionalized alumina in step S2 is surface primary amino aluminum oxide; then the long-chain organic molecule solution in step S3 is a double-ended epoxy long-chain organic molecule solution II, wherein the mass ratio of the bifunctional epoxy resin to the aromatic amine epoxy curing agent is 2:1 or 3:2 or 4:3 or 5:

4.

9. A method for preparing an anti-settling thermally conductive laminated film, characterized in that: The preparation method comprises: According to the mass fractions of the components of the anti-settling thermal conductive laminated film according to any one of claims 1 to 8, 20-80 parts of base epoxy resin, 10-50 parts of heat-resistant epoxy resin and 400-800 parts of modified alumina are weighed in a planetary mixer, and a solvent is added, stirred at 100-130° C. for 0.5-3 hours, mixed evenly, and cooled to room temperature to obtain a first slurry; Add 1-50 parts of a curing agent and 0.1-3 parts of a curing accelerator to the first slurry, and stir at room temperature for 20-60 minutes to obtain a uniformly mixed second slurry; The second slurry is evenly coated on the PET base film, placed in an oven for drying to remove the solvent, and the PET base film is removed to obtain an anti-settling thermal conductive laminated film with a thickness of 10-500 μm.

10. Use of the anti-settling thermally conductive laminated film according to any one of claims 1 to 8 in IC substrate packaging.

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