Interface filling material, preparation method and application thereof

Abstract

This invention discloses an interface filler material, its preparation method, and its application. The raw materials for preparing the interface filler material include: 75-90 parts by weight of thermally conductive filler, 3-5 parts by weight of polyurethane acrylate oligomer, 1.5-3 parts by weight of acrylate monomer, 0.5-2 parts by weight of UV initiator, 4-10 parts by weight of phase change material, and 1-5 parts by weight of additives. This improves the product performance of the interface filler material, especially significantly enhancing its thermal conductivity, hardness, flexibility, aging resistance, and cycle life.

Description

Technical Field

[0001] This invention belongs to the field of electronic thermal conductivity technology, specifically relating to an interface filling material, its preparation method, and its application. Background Technology

[0002] Thermal interface filler is a commonly used material in IC packaging and electronic heat dissipation. It is mainly used to fill the micro-gaps generated when two interface materials are combined or in contact. Because the surface of the interface material has uneven pores, the thermal resistance between the two interface materials increases. Filling the space between the two interface materials with thermal interface material can reduce the thermal resistance of heat transfer and improve the heat dissipation performance of the device.

[0003] Most existing interfacial thermal conductive materials use organosiloxanes or silicone oils as polymer protectors, adding large amounts of thermally conductive fillers and preparing them through intensive mixing or vacuum degassing and calendering. Interfacial thermal conductive materials prepared by these methods often exhibit poor thickness uniformity and may suffer from poor thermal conductivity, low hardness, poor flexibility, weak aging resistance, and short cycle life. Furthermore, the organic solvents used in the preparation process can negatively impact the environment and the health of operators. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the object of this invention is to provide an interface filling material, its preparation method, and its application. This improves the product performance of the interface filling material, particularly significantly enhancing its thermal conductivity, hardness, flexibility, aging resistance, and cycle life.

[0005] In one aspect of the invention, an interface filling material is provided. In an embodiment of the invention, the raw materials for preparing the interface filling material include: 75-90 parts by weight of the thermally conductive filler, 3-5 parts by weight of a polyurethane acrylate oligomer, 1.5-3 parts by weight of an acrylate monomer, 0.5-2 parts by weight of a UV initiator, 4-10 parts by weight of a phase change material, and 1-5 parts by weight of an additive.

[0006] According to embodiments of the present invention, a portion of polyurethane acrylate oligomers, a portion of acrylate monomers, and a portion of UV initiators react to obtain a polyurethane polymer. This polyurethane polymer endows the interface filler with advantages such as high flexibility, strong abrasion resistance, strong adhesion, aging resistance, and high tear strength. The polyurethane acrylate oligomers, with their good weather resistance, contribute to the interface filler's high strength and high toughness. By adding a phase change material, the interfacial thermal resistance can be reduced, which is beneficial for improving the thermal conductivity of the interface filler. Therefore, the product performance of the interface filler is improved, especially its thermal conductivity, hardness, flexibility, aging resistance, and cycle life are significantly enhanced.

[0007] In addition, the interface filling material according to the above embodiments of the present invention may also have the following additional technical features:

[0008] In some embodiments of the present invention, the raw materials of the interface filling material include: 80 to 90 parts by weight of the thermally conductive filler, 3 to 4 parts by weight of the polyurethane acrylate oligomer, 1.5 to 2 parts by weight of the acrylate monomer, 0.5 to 2 parts by weight of the UV initiator, 4 to 8 parts by weight of the phase change material, and 1 to 4 parts by weight of the additives.

[0009] In some embodiments of the present invention, the polyurethane acrylate oligomer includes at least one of polyether-type polyurethane oligomers and polyester-type polyurethane oligomers.

[0010] In some embodiments of the present invention, the acrylate monomer includes at least one selected from methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, isooctyl acrylate, isooctyl methacrylate, isobornyl acrylate, methyl isobornyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, and tripropylene glycol diacrylate.

[0011] In some embodiments of the present invention, the UV initiator includes at least one selected from 1-hydroxycyclohexylphenyl ketone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone.

[0012] In some embodiments of the present invention, the phase change material includes at least one of the following: n-hexadecane, n-heptadecane, n-octadecane, n-nonadecanane, n-icosane, n-docosane, n-tridecane, n-tetradecane, n-pentane, n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, n-triadecane, PEG1000, PEG2000, PEG4000, PEG6000, PEG10000, PEG20000, decanoic acid, lauric acid, myristic acid, palmitic acid, and stearic acid.

[0013] In some embodiments of the present invention, the adjuvant includes at least one selected from γ-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimeth(eth)oxysilane, vinyl-tris(2-methoxyethoxy)silane, isopropyl dioleoyloxy (dioctylphosphoyloxy), isopropoxytris(dodecylbenzenesulfonyloxy)titanate, isopropoxytris(dioctylpyrophosphoyloxy)titanate, isopropoxytris(dioctylpyrophosphoyloxy)titanate, isopropyl distearate aluminate, and isopropyl tristearate titanate.

[0014] In some embodiments of the present invention, the thermally conductive filler includes at least one selected from aluminum oxide, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, and silicon carbide.

[0015] In some embodiments of the present invention, the phase transition temperature of the phase change material is 20°C-60°C, preferably 28°C, 37°C, 42°C, 50°C and 58°C.

[0016] In some embodiments of the present invention, the phase change material is in the shape of a microcapsule.

[0017] In some embodiments of the present invention, the average particle size of the microcapsule phase change material is 3 micrometers to 50 micrometers.

[0018] In a second aspect, the present invention provides a method for preparing an interface filling material. In an embodiment of the present invention, the method includes:

[0019] (1) Mix the thermally conductive filler, polyurethane acrylate oligomer, acrylate monomer, UV initiator, phase change material and additives to obtain a mixed slurry;

[0020] (2) The mixed slurry is formed on the substrate, UV cured, and hot-pressed to form an interface filling material.

[0021] According to the method for preparing interface filler materials according to embodiments of the present invention, by adding polyurethane acrylate oligomers with good weather resistance, the interface filler material exhibits advantages such as high strength and high toughness. The acrylate monomers have good flowability and low viscosity; by adding acrylate monomers, the prepared interface filler material achieves good interface thickness uniformity. Furthermore, the acrylate monomers have numerous carbon-carbon double bonds, which significantly increases the crosslinking density of the UV-cured interface filler material. In addition, some polyurethane acrylate oligomers, some acrylate monomers, and some UV initiators react to form polyurethane polymers. These polyurethane polymers give the interface filler material advantages such as high flexibility, strong wear resistance, strong adhesion, aging resistance, and high tear strength. By adding phase change materials, the interfacial thermal resistance is reduced, which is beneficial to improving the thermal conductivity of the interface filler material. Therefore, the thickness uniformity of the interface filler material is improved, and the product performance of the interface filler material is enhanced, especially the thermal conductivity, hardness, flexibility, aging resistance, and cycle life are significantly improved. Moreover, the entire process of preparing the interface filler material does not use organic solvents, which helps to reduce the impact on the environment and the health of operators.

[0022] In addition, the method according to the above embodiments of the present invention may also have the following additional technical features:

[0023] In some embodiments of the present invention, step (1) further includes: (1-1) drying the thermally conductive filler to remove volatile impurities from the thermally conductive filler; (1-2) mixing the dried thermally conductive material and the additive to form a first mixture; (1-3) mixing the polyurethane acrylate oligomer, the acrylate monomer and the UV initiator to form a second mixture; (1-4) mixing the first mixture and the second mixture to form a third mixture; and (1-5) mixing the third mixture and the phase change material under vacuum to form a mixed slurry.

[0024] In some embodiments of the present invention, the substrate includes at least one of release paper and release film.

[0025] In some embodiments of the present invention, the method of forming the mixed slurry on the substrate is coating.

[0026] In some embodiments of the present invention, the temperature of the hot pressing is 60-100°C.

[0027] In a third aspect, the present invention provides a gap-filling material for electronic devices. According to embodiments of the present invention, the gap-filling material for electronic devices has the interface-filling material described in the above embodiments or the interface-filling material prepared by the method described in the above embodiments. This improves the interface thickness uniformity of the gap-filling material for electronic devices and significantly enhances its thermal conductivity, hardness, flexibility, aging resistance, and cycle life.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0030] Figure 1 This is a flowchart of a method for preparing an interface filling material according to an embodiment of the present invention;

[0031] Figure 2 This is a flowchart of a method for preparing a mixed slurry according to an embodiment of the present invention. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] In one aspect of the invention, an interface filling material is provided. In an embodiment of the invention, the raw materials for preparing the interface filling material include: 75-90 parts by weight of a thermally conductive filler, 3-5 parts by weight of a polyurethane acrylate oligomer, 1.5-3 parts by weight of an acrylate monomer, 0.5-2 parts by weight of a UV initiator, 4-10 parts by weight of a phase change material, and 1-5 parts by weight of an additive.

[0034] According to embodiments of the present invention, a portion of polyurethane acrylate oligomers, a portion of acrylate monomers, and a portion of UV initiators react to obtain a polyurethane polymer. This polyurethane polymer endows the interface filler with advantages such as high flexibility, strong abrasion resistance, strong adhesion, aging resistance, and high tear strength. The polyurethane acrylate oligomers, with their good weather resistance, contribute to the interface filler's high strength and high toughness. By adding a phase change material, the interfacial thermal resistance can be reduced, which is beneficial for improving the thermal conductivity of the interface filler. Therefore, the product performance of the interface filler is improved, especially its thermal conductivity, hardness, flexibility, aging resistance, and cycle life are significantly enhanced.

[0035] Furthermore, the inventors discovered that if the content of polyurethane acrylate oligomers is too low, it will lead to a decrease in the strength and flexibility of the interface filler material, which in turn will increase the interfacial thermal resistance and reduce the thermal conductivity of the interface filler material; if the content of polyurethane acrylate oligomers is too high, under the condition that the weight of the interface filler material is fixed, it will reduce the content of thermally conductive filler, which will lead to a decrease in the thermal conductivity of the interface filler material.

[0036] Furthermore, the inventors discovered that if the content of acrylate monomers is too low, the viscosity of the slurry used to prepare the interface filler material will be high, which will affect the consistency of the interface thickness of the prepared interface filler material and result in poor crosslinking density of the interface filler material after UV curing. If the content of acrylate monomers is too high, the drying time of the slurry used to prepare the interface filler material will be too long, and the crosslinking density of the interface filler material will be too high, thereby reducing the flexibility of the interface filler material.

[0037] Furthermore, if the content of thermally conductive filler is too low, it will lead to a decrease in the thermal conductivity of the interface filler material. If the content of thermally conductive filler is too high, it will lead to a decrease in the strength and flexibility of the interface filler material, which in turn will increase the interfacial thermal resistance of the interface filler material and reduce its thermal conductivity.

[0038] Furthermore, if the UV initiator content is too low, it will affect the amount of polyurethane polymer generated, resulting in a decrease in the strength and flexibility of the interface filler material. If the UV initiator content is too high, it will lead to a decrease in the hardness of the interface filler material and an increase in VOC.

[0039] Furthermore, if the content of phase change material is too low, the effect of reducing interfacial thermal resistance will be weakened, thereby reducing the thermal conductivity of the thermally conductive filler. If the content of phase change material is too high, the amount of thermally conductive filler will be reduced when the weight of the interfacial filler is constant, thus reducing the thermal conductivity of the interfacial filler.

[0040] Furthermore, if the content of additives is too low, it will reduce the thermal conductivity of the thermally conductive filler material; if the content of additives is too high, it may affect the hardness, flexibility and thermal conductivity of the interface filler material.

[0041] According to a specific embodiment of the present invention, the raw materials of the above-mentioned interface filler material include: 80-90 parts by weight of the above-mentioned thermally conductive filler, 3-4 parts by weight of the above-mentioned polyurethane acrylate oligomer, 1.5-2 parts by weight of the above-mentioned acrylate monomer, 0.5-2 parts by weight of the above-mentioned UV initiator, 4-8 parts by weight of the above-mentioned phase change material, and 1-4 parts by weight of the above-mentioned additives. This is more conducive to improving the product performance of the interface filler material, especially significantly improving its thermal conductivity, hardness, flexibility, aging resistance, and cycle life.

[0042] In the embodiments of the present invention, the types of polyurethane acrylate oligomers are not specifically limited, and those skilled in the art can select them according to the actual situation. As a preferred embodiment, the polyurethane acrylate oligomers include at least one of polyether-type polyurethane oligomers and polyester-type polyurethane oligomers.

[0043] According to another specific embodiment of the present invention, the carbon content of the above-mentioned polyurethane acrylate oligomer is 40-50%, thereby avoiding the situation where the carbon content of the polyurethane acrylate oligomer is too high, resulting in too high viscosity of the polyurethane acrylate oligomer, which is not conducive to the good dispersion of thermally conductive filler in interface filling material.

[0044] In the embodiments of the present invention, the types of acrylate monomers are not specifically limited, and those skilled in the art can select them according to the actual situation. As a preferred embodiment, the acrylate monomers include at least one of methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, isooctyl acrylate, isooctyl methacrylate, isobornyl acrylate, methyl isobornyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, and tripropylene glycol diacrylate, thereby helping to reduce the impact on the environment and the health of operators.

[0045] In the embodiments of the present invention, the type of UV initiator is not specifically limited, and those skilled in the art can select it according to the actual situation. As a preferred embodiment, the UV initiator includes at least one of 1-hydroxycyclohexylphenyl ketone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone.

[0046] In the embodiments of the present invention, the types of the above-mentioned additives are not specifically limited, and those skilled in the art can select them according to the actual situation. As a preferred embodiment, the above-mentioned additives include at least one of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimeth(eth)oxysilane, vinyl-tris(2-methoxyethoxy)silane, isopropyl dioleoyloxy (dioctylphosphoyloxy), isopropoxytris(dodecylbenzenesulfonyloxy)titanate, isopropoxytris(dioctylpyrophosphate)titanate, isopropoxytris(dioctylpyrophosphate)titanate, isopropyl distearate aluminate, and isopropyl tristearate titanate.

[0047] According to another specific embodiment of the present invention, the above-mentioned additive is a coupling agent. Based on the total mass of the interface filler material, the content of the coupling agent is 1% to 5%. Thus, by controlling the content of the coupling agent within the above range, it is possible to avoid the following: if the content of the coupling agent is too small, the dispersibility of the thermally conductive filler will be poor, and there may be an interface effect between the thermally conductive filler and the polymer, which will lead to a decrease in the thermal conductivity of the interface filler material; if the content of the coupling agent is too large, a bridging effect may occur, which will lead to the agglomeration of the thermally conductive filler, which will have an adverse effect on the hardness, flexibility and thermal conductivity of the interface filler material.

[0048] In the embodiments of the present invention, the type of thermally conductive filler is not particularly limited, and those skilled in the art can select it according to the actual situation. As a preferred embodiment, the thermally conductive filler includes at least one of alumina, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, and silicon carbide.

[0049] In the embodiments of the present invention, the particle size of the thermally conductive filler is not specifically limited, and those skilled in the art can select it according to the actual situation. As a preferred option, the particle size of the thermally conductive filler is 1 micrometer to 200 micrometers. This allows the thermally conductive material to be better distributed inside the microcapsule phase change material, thereby making the thermal conductivity of the microcapsule phase change material constant and uniform at all locations.

[0050] In the embodiments of the present invention, the types of phase change materials are not specifically limited, and those skilled in the art can select them according to the actual situation. As a specific example, the phase change materials include straight-chain alkanes, such as n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, n-timodecane, n-timodecane, n-timodecane, n-pentane, n-hexadecane, n-octadecane, n-nonadecane, and n-triane; polyethers, such as PEG1000, PEG2000, PEG4000, PEG6000, PEG10000, and PEG20000; and fatty acids, such as at least one of decanoic acid, lauric acid, myristic acid, palmitic acid, and stearic acid. Thus, the phase change material can change from solid to liquid during the phase change process, resulting in a lower thermal resistance in the interface filling material.

[0051] According to another specific embodiment of the present invention, the phase transition temperature of the above-mentioned phase change material is 20℃-60℃, preferably 28℃, 37℃, 42℃, 50℃, or 58℃. Thus, controlling the phase transition temperature of the above-mentioned phase change material within the above range is beneficial to effectively reduce the interfacial thermal resistance during use.

[0052] According to another specific embodiment of the present invention, the phase change material is in the shape of a microcapsule, which is beneficial to the dispersion of the phase change material in the interface filling material and avoids leakage of the phase change material, thereby contaminating the interface.

[0053] According to another specific embodiment of the present invention, the average particle size of the microcapsule phase change material is 3 micrometers to 50 micrometers. This avoids both the problem of the average particle size of the microcapsule phase change material being too small, resulting in a low weight ratio of the phase change material, which would be detrimental to reducing the interfacial thermal resistance, and the problem of the average particle size of the microcapsule phase change material being too large, which would be detrimental to the dispersion of the microcapsule phase change material in the interfacial filling material, and thus affect the thickness uniformity of the interface.

[0054] In a second aspect, the present invention provides a method for preparing an interface filling material. In embodiments of the present invention, reference is made to the appendix. Figure 1 The above methods include:

[0055] S100: A mixed slurry is prepared by mixing thermally conductive filler, polyurethane acrylate oligomer, acrylate monomer, UV initiator, phase change material, and additives.

[0056] In this step, thermally conductive fillers, polyurethane acrylate oligomers, acrylate monomers, UV initiators, phase change materials, and additives are mixed to obtain a mixed slurry.

[0057] In embodiments of the present invention, reference is made to the appendix. Figure 2 Step S100 further includes:

[0058] S101: Dry the thermally conductive filler

[0059] In this step, drying the thermally conductive filler can remove volatile impurities from the filler, thereby improving its thermal conductivity.

[0060] In the embodiments of the present invention, the apparatus for drying the thermally conductive filler is not particularly limited, and any apparatus that can achieve the heating and drying effect is acceptable.

[0061] S102: Mix the dried thermally conductive material and additives to form a first mixture.

[0062] In this step, the dried thermally conductive material and additives are mixed to form a first mixture. This improves the compatibility between the thermally conductive material and the polymer, thereby reducing the interfacial thermal resistance between the polymer and the thermally conductive material.

[0063] According to a specific embodiment of the present invention, a mixer is used to mix the dried thermally conductive material and the additives. The mixer is paused every 20-40 seconds to cool down, and the cumulative mixing time is 2-3 minutes. This ensures that the thermally conductive material and the additives are mixed evenly and avoids the thermally conductive filler from degenerating due to heat.

[0064] S103: A second mixture is formed by mixing polyurethane acrylate oligomers, acrylate monomers, and a UV initiator.

[0065] In this step, polyurethane acrylate oligomers, acrylate monomers, and UV initiators are mixed. A portion of the polyurethane acrylate oligomers, a portion of the acrylate monomers, and a portion of the UV initiator react to obtain a polyurethane polymer. This polyurethane polymer gives the interfacial filler material advantages such as high flexibility, high abrasion resistance, strong adhesion, aging resistance, and high tear strength.

[0066] S104: Mix the first mixture and the second mixture to form a third mixture.

[0067] In this step, the first mixture and the second mixture are combined to form a third mixture. This ensures that each surface of the thermally conductive filler can come into contact with the second mixture.

[0068] S105: The third mixture and the phase change material are mixed in a vacuum environment to form a mixed slurry.

[0069] In this step, the third mixture and the phase change material are mixed under vacuum to form a slurry. This helps prevent the formation of bubbles during mixing and ensures that the coated interfacial thermally conductive material has a good appearance.

[0070] S200: The mixed slurry is formed on the substrate, UV cured, and then hot-pressed to form an interface filler material.

[0071] In this step, the mixed slurry is formed on the substrate, and then UV-cured and hot-pressed to form an interface filling material. The substrate, as a support, helps to improve the thickness uniformity of the interface thermal conductive material. UV curing helps to improve the strength and flexibility of the interface thermal conductive material, and hot pressing helps to improve the thermal conductivity of the interface thermal conductive material.

[0072] According to the method for preparing interface filler materials according to embodiments of the present invention, by adding polyurethane acrylate oligomers with good weather resistance, the interface filler material exhibits advantages such as high strength and high toughness. The acrylate monomers have good flowability and low viscosity; by adding acrylate monomers, the prepared interface filler material achieves good interface thickness consistency. Furthermore, the acrylate monomers have numerous carbon-carbon double bonds, which significantly increases the crosslinking density of the UV-cured interface filler material. In addition, some polyurethane acrylate oligomers, some acrylate monomers, and some UV initiators react to form polyurethane polymers. These polyurethane polymers give the interface filler material advantages such as high flexibility, strong wear resistance, strong adhesion, aging resistance, and high tear strength. By adding phase change materials, the interfacial thermal resistance is reduced, which is beneficial to improving the thermal conductivity of the interface filler material. Therefore, the interface thickness consistency of the interface filler material is improved, and the product performance of the interface filler material is enhanced, especially the thermal conductivity, hardness, flexibility, aging resistance, and cycle life are significantly improved. Moreover, the entire process of preparing the interface filler material does not use organic solvents, which helps to reduce the impact on the environment and the health of operators.

[0073] In the embodiments of the present invention, the type of substrate is not specifically limited, and those skilled in the art can select it according to the actual situation. As a preferred option, the substrate includes at least one of release paper and release film.

[0074] According to another specific embodiment of the present invention, the solid content of the above-mentioned polyurethane acrylate oligomer is 70%-80%. This avoids both excessively low solid content of the polyurethane acrylate oligomer, which would lead to excessive solvent content and hinder the drying and evaporation of the solvent, and excessively high solid content of the polyurethane acrylate oligomer, which would lead to excessive viscosity of the polyurethane acrylate oligomer and hinder the evaporation and drying of the thermally conductive filler.

[0075] According to another specific embodiment of the present invention, the method of forming the above-mentioned mixed slurry on the above-mentioned substrate is coating. The coating method is simple and easy to implement. Therefore, the coating method can realize the continuous and mass production of interface filling materials.

[0076] According to another specific embodiment of the present invention, the hot pressing temperature is 60°C-100°C. Therefore, controlling the hot pressing temperature within the above range is beneficial for the mixed slurry to bond with the substrate and form an interface filling material.

[0077] According to another specific embodiment of the present invention, the pressure of the hot pressing is 0.3-0.6 MPa. Therefore, controlling the pressure of the hot pressing within the above range is beneficial to the bonding of the mixed slurry with the substrate to form an interface filling material.

[0078] In a third aspect, the present invention provides a gap-filling material for electronic devices. According to embodiments of the present invention, the gap-filling material for electronic devices has the interface-filling material described in the above embodiments or the interface-filling material prepared by the method described in the above embodiments. This improves the interface thickness uniformity of the gap-filling material for electronic devices and significantly enhances its thermal conductivity, hardness, flexibility, aging resistance, and cycle life.

[0079] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0080] Example 1

[0081] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0082] (1) First, weigh 75g of spherical alumina, 10g of n-octadecane (phase change temperature 28℃), 5g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 5g of polyether-type polyurethane oligomer, 3g of tripropylene glycol diacrylate, and 2g of 1-hydroxycyclohexylphenyl ketone; place the spherical alumina in a drying oven and dry it at 120℃ for 10 hours in order to remove volatile impurities from the spherical alumina;

[0083] (2) Mix γ-(2,3-epoxypropoxy)propyltrimethoxysilane with spherical alumina in a high-speed mixer. Stop the high-speed mixer after each 20-second high-speed mixing to allow the mixer to dissipate heat. Then continue mixing for the next time to avoid prolonged high-speed friction between the mixer blades and the spherical alumina, which could cause the spherical alumina to denature due to heat. Mix for a total of 2 minutes to prevent the spherical alumina from clumping and to ensure that γ-(2,3-epoxypropoxy)propyltrimethoxysilane is evenly dispersed in the spherical alumina to form the first mixture.

[0084] (3) The above polyether polyurethane oligomer, tripropylene glycol diacrylate and 1-hydroxycyclohexylphenyl ketone are mixed with a stirrer to form a second mixture. The stirring speed is 500 rpm / min and the stirring time is 30 min.

[0085] (4) The first mixture is mixed with the second mixture in multiple batches using a stirrer to form the third mixture. The stirring speed is 1500 rpm / min and the stirring time is 120 min. Then the third mixture and the n-octadecane microcapsules are mixed in a vacuum environment to form a mixed slurry.

[0086] (5) Select a PET release film with a release force of 100gf, and apply the mixed slurry onto the PET release film using a slot coating method. Then, use a UV lamp (20mW / cm²) to apply the mixture. 2 After being irradiated with 365nm for a certain period of time, it is then laminated with a 100gf PET release film during winding, with a lamination pressure of 0.5MPa and a hot pressing temperature of 80℃, thereby forming an interface filling material.

[0087] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 1.

[0088] Example 2

[0089] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0090] The only difference between this embodiment and Embodiment 1 is that:

[0091] In step (1), 5g of polyether-type polyurethane oligomer was replaced with 4g of polyester-type polyurethane oligomer; the performance of the above interface filler material was tested, and the test results are shown in Table 1.

[0092] Example 3

[0093] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0094] The only difference between this embodiment and Embodiment 1 is that:

[0095] In step (1), the mass of the polyether polyurethane oligomer is 3g;

[0096] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 1.

[0097] Example 4

[0098] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0099] The only difference between this embodiment and Embodiment 1 is that:

[0100] In step (1), 3g of tripropylene glycol diacrylate was replaced with 2g of hydroxyethyl methacrylate; the performance of the above interface filler material was tested, and the test results are shown in Table 1.

[0101] Example 5

[0102] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0103] The only difference between this embodiment and Embodiment 1 is that:

[0104] In step (1), the mass of tripropylene glycol diacrylate is 1.5 g;

[0105] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 1.

[0106] Example 6

[0107] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0108] The only difference between this embodiment and Embodiment 1 is that:

[0109] In step (1), the mass of the spherical magnesium oxide is 85g;

[0110] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 1.

[0111] Example 7

[0112] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0113] The only difference between this embodiment and Embodiment 1 is that:

[0114] In step (1), the mass of the spherical alumina is 90g;

[0115] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 1.

[0116] Example 8

[0117] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0118] The only difference between this embodiment and Embodiment 1 is that:

[0119] In step (1), 10g of n-octadecane (phase change temperature 28℃) was replaced with 4g of lauric acid (phase change temperature 42℃); the performance of the above interface filling material was tested, and the test results are shown in Table 1.

[0120] Example 9

[0121] This embodiment provides a method for preparing an interface filling material, the steps of which are as follows:

[0122] The only difference between this embodiment and Embodiment 1 is that:

[0123] In step (1), 10g of n-octadecane (phase change temperature 28℃) was replaced with 7g of myristic acid (phase change temperature 58℃); the performance of the above interface filling material was tested, and the test results are shown in Table 1.

[0124] Comparative Example 1

[0125] This comparative example provides a method for preparing an interface filling material, the steps of which are as follows:

[0126] The only difference between this comparative example and Example 1 is that:

[0127] In step (1), the mass of the polyether polyurethane oligomer is 6g;

[0128] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 2.

[0129] Comparative Example 2

[0130] This comparative example provides a method for preparing an interface filling material, the steps of which are as follows:

[0131] The only difference between this comparative example and Example 1 is that:

[0132] In step (1), the mass of the polyether-type polyurethane oligomer is 2g;

[0133] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 2.

[0134] Comparative Example 3

[0135] This comparative example provides a method for preparing an interface filling material, the steps of which are as follows:

[0136] The only difference between this comparative example and Example 1 is that:

[0137] In step (1), the mass of tripropylene glycol diacrylate is 1 g;

[0138] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 2.

[0139] Comparative Example 4

[0140] This comparative example provides a method for preparing an interface filling material, the steps of which are as follows:

[0141] The only difference between this comparative example and Example 1 is that:

[0142] In step (1), the mass of tripropylene glycol diacrylate is 4g;

[0143] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 2.

[0144] Comparative Example 5

[0145] This comparative example provides a method for preparing an interface filling material, the steps of which are as follows:

[0146] The only difference between this comparative example and Example 1 is that:

[0147] In step (1), the mass of the spherical alumina is 60g;

[0148] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 2.

[0149] Comparative Example 6

[0150] This comparative example provides a method for preparing an interface filling material, the steps of which are as follows:

[0151] The only difference between this comparative example and Example 1 is that:

[0152] In step (1), the mass of the spherical alumina is 100g;

[0153] The performance of the above-mentioned interface filling materials was tested, and the test results are shown in Table 2.

[0154] The material properties of the interface filling materials prepared in Examples 1-9 are compared, as shown in Table 1. The material properties of the interface filling materials prepared in Comparative Examples 1-6 are compared, as shown in Table 2.

[0155] Table 1

[0156]

[0157] Table 2

[0158]

[0159] Note: Aging conditions: 70℃, 500 hours.

[0160] As can be readily seen from Tables 1 and 2, the interface filler material prepared in this application exhibits good interface thickness consistency and excellent thermal conductivity, aging resistance, and cycle performance. Furthermore, since the interface filler material of this application contains a polyurethane polymer, it possesses the advantages of high strength and high flexibility.

[0161] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An interface filling material, characterized in that, The raw materials for preparing the interface filler material include: 75-90 parts by weight of thermally conductive filler, 3-5 parts by weight of polyurethane acrylate oligomer, 1.5-3 parts by weight of acrylate monomer, 0.5-2 parts by weight of UV initiator, 4-10 parts by weight of phase change material, and 1-5 parts by weight of additives. The polyurethane acrylate oligomer includes at least one of polyether-type polyurethane oligomers and polyester-type polyurethane oligomers; The acrylate monomer is hydroxyethyl methacrylate or tripropylene glycol diacrylate; The phase change material is n-octadecane, lauric acid, or myristic acid; The phase change material is in the shape of a microcapsule; The UV initiator is 1-hydroxycyclohexylphenyl ketone; The auxiliary agent is γ-(2,3-epoxypropoxy)propyltrimethoxysilane; The thermally conductive filler is aluminum oxide or magnesium oxide.

2. The interface filling material according to claim 1, characterized in that, The raw materials include: 80-90 parts by weight of the thermally conductive filler, 3-4 parts by weight of the polyurethane acrylate oligomer, 1.5-2 parts by weight of the acrylate monomer, 0.5-2 parts by weight of the UV initiator, 4-8 parts by weight of the phase change material, and 1-4 parts by weight of the additives.

3. The interface filling material according to any one of claims 1 or 2, characterized in that, The phase change temperature of the phase change material is 20℃-60℃.

4. The interface filling material according to claim 3, characterized in that, The phase transition temperatures of the phase change material are 28℃, 37℃, 42℃, 50℃ and 58℃.

5. The interface filling material according to claim 1 or 2, characterized in that, The average particle size of the microcapsule phase change material is 3 micrometers to 50 micrometers.

6. A method for preparing the interface filling material according to any one of claims 1-5, characterized in that: (1) The thermally conductive filler, polyurethane acrylate oligomer, acrylate monomer, UV initiator, phase change material and additives are mixed to obtain a mixed slurry; (2) The mixed slurry is formed on the substrate, UV cured, and hot-pressed to form an interface filling material.

7. The method according to claim 6, characterized in that, Step (1) also includes: (1-1) The thermally conductive filler is dried in order to remove volatile impurities from the thermally conductive filler; (1-2) The dried thermally conductive filler and the additive are mixed to form a first mixture; (1-3) The polyurethane acrylate oligomer, the acrylate monomer and the UV initiator are mixed to form a second mixture; (1-4) The first mixture and the second mixture are mixed to form a third mixture; (1-5) The third mixture and the phase change material are mixed in a vacuum environment to form a mixed slurry.

8. The method according to claim 6 or 7, characterized in that, The substrate includes at least one of release paper and release film.

9. The method according to claim 6 or 7, characterized in that, The method of forming the mixed slurry on the substrate is by coating; And / or, the temperature of the hot pressing is 60 to 100°C.

10. A gap-filling material for electronic devices, characterized in that, The interface filling material includes the interface filling material according to any one of claims 1-5 or the interface filling material prepared by the method according to any one of claims 6-9.

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