Heat conduction element, preparation method thereof and electronic equipment

Abstract

The invention relates to a heat-conducting element, a preparation method thereof and electronic equipment, and belongs to the technical field of heat-conducting elements. The heat conduction element comprises the following raw materials in parts by mass: 30-60 parts of a matrix containing vinyl polysiloxane and a flexible copolymer; 800 parts to 1200 parts of heat conducting filler; 0.05 part to 0.15 part of an inhibitor; 1-8 parts of a cross-linking agent; 2-6 parts of a catalyst; wherein the flexible copolymer comprises a block copolymer of polysiloxane and / or a graft copolymer of polysiloxane. The heat-conducting element provided by the embodiment of the invention can give consideration to both high heat-conducting property and rebound resilience.

Description

Technical Field

[0001] The present application relates to the technical field of thermal conductive elements, and in particular to a thermal conductive element, a preparation method thereof, and an electronic device. Background Art

[0002] With the miniaturization of electronic devices, internal heat accumulation is becoming an increasingly serious problem. As a core component in thermal management, thermal conductive elements must create an efficient heat transfer channel between the heating element and the heat sink. Silicone-based thermal pads, with their flexible fit, stable insulation, and strong weather resistance, have become a mainstream solution. However, current thermal conductive elements cannot achieve both high thermal conductivity and high resilience. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of the embodiments of the present application includes providing a thermal conductive element, a preparation method thereof, and an electronic device to improve the technical problem that the thermal conductive element cannot achieve both high thermal conductivity and resilience.

[0004] In a first aspect, an embodiment of the present application provides a heat conducting element, wherein the raw materials of the heat conducting element include, in parts by mass: A matrix comprising 30 to 60 parts of vinyl polysiloxane and a flexible copolymer; Thermal conductive filler, 800~1200 parts; Inhibitor, 0.05 to 0.15 parts; Cross-linking agent, 1 to 8 parts; Catalyst, 2 to 6 parts; The flexible copolymer includes a block copolymer of polysiloxane and / or a graft copolymer of polysiloxane.

[0005] In the thermally conductive element provided in the embodiments of the present application, appropriate raw material components and their contents are selected. In particular, the addition of a flexible copolymer to the matrix can increase the intersegment gaps and reduce the crosslink density, resulting in a highly flexible network structure. This not only ensures excellent thermal conductivity but also enhances the element's resilience. Thus, the thermally conductive element provided in the embodiments of the present application achieves both high thermal conductivity and resilience.

[0006] In some embodiments of the present application, the matrix comprises a mixture of the vinyl polysiloxane and the flexible copolymer, and the mass ratio of the vinyl polysiloxane to the flexible copolymer is (1-4):1.

[0007] In some embodiments of the present application, the vinyl polysiloxane includes vinyl terminated polydimethylsiloxane.

[0008] In some embodiments of the present application, the flexible copolymer comprises at least one of a polydimethylsiloxane-polyethylene glycol block copolymer, a polydimethylsiloxane-polytetrahydrofuran ether glycol block copolymer, and a polydimethylsiloxane-polybutadiene graft copolymer.

[0009] In some embodiments of the present application, in the polydimethylsiloxane-polyethylene glycol block copolymer, the weight average molecular weight of the polyethylene glycol is 1000 g / mol to 5000 g / mol.

[0010] In some embodiments of the present application, the mass fraction of the polyethylene glycol in the polydimethylsiloxane-polyethylene glycol block copolymer is 40% to 60%.

[0011] In some embodiments of the present application, in the polydimethylsiloxane-polytetrahydrofuran ether glycol block copolymer, the weight average molecular weight of the polytetrahydrofuran ether glycol is 1000 g / mol to 5000 g / mol.

[0012] In some embodiments of the present application, the mass fraction of the polytetrahydrofuran ether glycol in the polydimethylsiloxane-polytetrahydrofuran ether glycol block copolymer is 40% to 60%.

[0013] In some embodiments of the present application, in the polydimethylsiloxane-polybutadiene graft copolymer, the weight average molecular weight of the polybutadiene is 1000 g / mol to 5000 g / mol.

[0014] In some embodiments of the present application, the grafting degree of the polydimethylsiloxane-polybutadiene graft copolymer is 5% to 15%.

[0015] In some embodiments of the present application, the thermally conductive filler comprises a coupling agent modified thermally conductive filler.

[0016] In some embodiments of the present application, the particle size of the thermally conductive filler is 0.1 μm to 150 μm.

[0017] In some embodiments of the present application, the mass fraction of the thermally conductive filler with a particle size greater than 80 μm and less than or equal to 150 μm, based on the total mass of the thermally conductive filler, is 30% to 45%.

[0018] In some embodiments of the present application, the mass fraction of the thermally conductive filler with a particle size greater than 30 μm and less than or equal to 80 μm, based on the total mass of the thermally conductive filler, is 15% to 25%.

[0019] In some embodiments of the present application, the mass fraction of the thermally conductive filler with a particle size greater than 5 μm and less than or equal to 30 μm, based on the total mass of the thermally conductive filler, is 20% to 30%.

[0020] In some embodiments of the present application, based on the total mass of the thermally conductive filler, the mass of the thermally conductive filler having a particle size greater than 1 μm and less than or equal to 5 μm accounts for 5% to 10%.

[0021] In some embodiments of the present application, based on the total mass of the thermally conductive filler, the mass of the thermally conductive filler having a particle size greater than or equal to 0.1 μm and less than or equal to 1 μm accounts for 1% to 10%.

[0022] In some embodiments of the present application, the weight average molecular weight of the vinyl polysiloxane is 1000 g / mol to 10000 g / mol.

[0023] In some embodiments of the present application, the viscosity of the vinyl polysiloxane is 100 mPa·s to 20,000 mPa·s.

[0024] In some embodiments of the present application, the thermally conductive filler includes at least one of metal oxide and nitride.

[0025] In some embodiments of the present application, the inhibitor comprises an alkynol inhibitor.

[0026] In some embodiments of the present application, the coupling agent includes a silane coupling agent.

[0027] In some embodiments of the present application, the cross-linking agent includes hydrogen-containing silicone oil.

[0028] In some embodiments of the present application, the catalyst includes a noble metal catalyst.

[0029] In some embodiments of the present application, the thermally conductive filler includes at least one of aluminum oxide, aluminum nitride, zinc oxide, and boron nitride.

[0030] In some embodiments of the present application, the inhibitor includes at least one of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3-methyl-1-dodecyn-3-ol.

[0031] In some embodiments of the present application, the coupling agent includes at least one of 3-aminopropyltriethoxysilane, γ-glyceroxypropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and hexadecyltriethoxysilane.

[0032] In some embodiments of the present application, the viscosity of the hydrogen-containing silicone oil is 100 mPa·s to 500 mPa·s.

[0033] In some embodiments of the present application, the mass proportion of active hydrogen in the hydrogen-containing silicone oil is 0.02% to 0.4% of the hydrogen-containing silicone oil.

[0034] In some embodiments of the present application, the catalyst includes at least one of a platinum catalyst, a rhodium catalyst, and a palladium catalyst.

[0035] In a second aspect, an embodiment of the present application provides a method for preparing a thermally conductive element as described in any embodiment of the first aspect of the present application, comprising the following steps: Mixing the raw materials of the heat conducting element to obtain a mixed raw material; The mixed raw material is subjected to vacuum degassing, calendering and curing treatment to obtain the thermal conductive element.

[0036] In some embodiments of the present application, the step of mixing the raw materials of the thermal conductive element to obtain the mixed raw materials includes the following steps: Performing a first mixing process on the vinyl polysiloxane and the flexible copolymer to obtain a matrix; Using a coupling agent to perform surface modification treatment on the thermally conductive filler to increase the compatibility between the thermally conductive filler and the matrix, thereby obtaining a surface-modified thermally conductive filler; The matrix, the surface-modified thermally conductive filler, the inhibitor, the cross-linking agent and the catalyst are mixed for a second time to obtain the mixed raw material.

[0037] In some embodiments of the present application, the time of the first mixing treatment is 4 hours to 8 hours.

[0038] In some embodiments of the present application, the temperature of the first mixing treatment is 80°C to 120°C.

[0039] In some embodiments of the present application, the temperature of the surface modification treatment is 50°C~80°C.

[0040] In some embodiments of the present application, the stirring rate of the surface modification treatment is 60 rpm / min to 120 rpm / min.

[0041] In some embodiments of the present application, the second mixing process is performed under a vacuum gauge pressure of -0.08 MPa to -0.10 MPa.

[0042] In some embodiments of the present application, the processing time of the second mixing treatment is 30 minutes to 60 minutes.

[0043] In some embodiments of the present application, the vacuum gauge pressure of the vacuum degassing treatment is -0.08 MPa to -0.10 MPa.

[0044] In some embodiments of the present application, the vacuum defoaming treatment lasts for 20 minutes to 60 minutes.

[0045] In some embodiments of the present application, the curing temperature is 100°C to 150°C.

[0046] In some embodiments of the present application, the curing treatment time is 15 minutes to 30 minutes.

[0047] In a third aspect, an embodiment of the present application provides an electronic device, comprising the thermal conductive element in any embodiment of the first aspect of the present application or the thermal conductive element prepared by the preparation method in any embodiment of the second aspect of the present application. DETAILED DESCRIPTION

[0048] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​listed are 1 and 2, and if the maximum range values ​​listed are 3, 4, and 5, then the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, wherein a and b are both real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0049] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0050] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0051] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0052] As used herein, the expression "comprising" or its synonymous similar expressions "including," "containing," and "having" are open ended and do not exclude additional unrecited elements, steps, or ingredients. The expression "consisting of excludes any elements, steps, or ingredients not specified. The expression "consisting essentially of" means that the scope is limited to the specified elements, steps, or ingredients, plus any optional elements, steps, or ingredients that do not materially affect the basic and novel characteristics of the claimed subject matter. It should be understood that the expression "comprising" encompasses the expressions "consisting essentially of" and "consisting of."

[0053] As used herein, the expression "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and the description includes both occurring and not occurring.

[0054] Herein, the expression "one or more" or "at least one" may mean 1, 2, 3, 4, 5, 6, 7, 8, 9 or more.

[0055] As used herein, the expression "and / or" encompasses both "and" and "or." Elements qualified by "and / or" encompass any one of them and any combination thereof. For example, A and / or B encompasses A, B, and A+B. A, B, and / or C encompasses A, B, C, A+B, A+C, B+C, and A+B+C.

[0056] With the miniaturization of electronic devices, internal heat will accumulate rapidly. If the heat is not dissipated in time, the internal heat accumulation of the electronic equipment will lead to a decline in device performance and damage to reliability. Therefore, it is necessary to introduce a thermal conductive element between the electronic device and the radiator to fill the microscopic gap between the electronic device and the radiator and improve the heat conduction efficiency. Due to its advantages such as flexible fitting, stable insulation and strong weather resistance, the thermal conductive element can quickly and effectively transfer heat to the radiator so that the heat can be dissipated in time. In order to meet the high thermal conductivity requirements, a large amount of thermal conductive filler is usually required to be added to the thermal conductive element, but the high filler content will cause the rigidity of the silicone network to increase significantly and the rebound performance to decrease significantly, thereby weakening the interface bonding stability and reducing the heat dissipation effect.

[0057] In view of this, embodiments of the present application provide a heat-conducting element, a preparation method thereof, and an electronic device, wherein the heat-conducting element can achieve both high thermal conductivity and resilience.

[0058] In a first aspect, an embodiment of the present application provides a heat conducting element, wherein the raw materials of the heat conducting element include, in parts by mass: A matrix comprising 30 to 60 parts of vinyl polysiloxane and a flexible copolymer; Thermal conductive filler, 800~1200 parts; Inhibitor, 0.05 to 0.15 parts; Cross-linking agent, 1 to 8 parts; Catalyst, 2 to 6 parts; The flexible copolymer includes a block copolymer of polysiloxane and / or a graft copolymer of polysiloxane.

[0059] In the thermally conductive element provided in the embodiments of the present application, appropriate raw material components and their contents are selected. In particular, the addition of a flexible copolymer to the matrix can increase the intersegment gaps and reduce the crosslink density, resulting in a highly flexible network structure. This not only ensures excellent thermal conductivity but also enhances the element's resilience. Thus, the thermally conductive element provided in the embodiments of the present application achieves both high thermal conductivity and resilience.

[0060] In the above-described embodiment, the thermally conductive element has high resilience, which improves interfacial bonding stability. This maintains good contact stress between the electronic device and the thermal silicone element, and between the thermally conductive element and the heat sink, reducing stress relaxation. This reduces interfacial gaps caused by increased hardness and stress relaxation due to long-term use, thereby improving thermal conductivity. Furthermore, the thermally conductive element also offers high thermal conductivity, resulting in excellent heat dissipation.

[0061] In the above embodiment, the matrix includes vinyl polysiloxane and a flexible copolymer. It can be understood that the matrix can be composed of two independent components, vinyl polysiloxane and a flexible copolymer, but the two components have not reacted or mixed; the matrix can also be a mixture formed by mixing vinyl polysiloxane and a flexible copolymer.

[0062] In some embodiments, the matrix comprises a mixture of vinyl polysiloxane and a flexible copolymer, wherein the mass ratio of vinyl polysiloxane to the flexible copolymer is (1-4):1.

[0063] In the above embodiment, the mass ratio of vinyl polysiloxane to the flexible copolymer is within the above range, which can not only make the thermal conductive element have good resilience, but also allow more thermal conductive fillers to be distributed inside to further improve its thermal conductivity.

[0064] For example, the mass ratio of vinyl polysiloxane to the flexible copolymer may be, but is not limited to, 1:1, 2:1, 3:1, 4:1, etc.

[0065] In some embodiments, the vinyl polysiloxane includes vinyl terminated polydimethylsiloxane (abbreviated as Vi-PDMS-Vi).

[0066] In some embodiments, the flexible copolymer includes at least one of a polydimethylsiloxane-polyethylene glycol block copolymer (abbreviated as PDMS-PEG), a polydimethylsiloxane-polytetramethylene glycol block copolymer (abbreviated as PDMS-PTHF), and a polydimethylsiloxane-polybutadiene graft copolymer (abbreviated as PDMS-PBD).

[0067] In the above embodiment, the PEG segment, PTHF segment or PBD in the flexible copolymer can provide additional stretching ability, thereby achieving a rebound rate of greater than or equal to 60% after 50% compression while maintaining a thermal conductivity of the thermal conductive element greater than or equal to 5 W / m·K.

[0068] In some embodiments, in the polydimethylsiloxane-polyethylene glycol block copolymer, the weight average molecular weight of the polyethylene glycol is 1000 g / mol to 5000 g / mol.

[0069] In some embodiments, in the polydimethylsiloxane-polytetramethylene ether glycol block copolymer, the weight average molecular weight of polytetramethylene ether glycol is 1000 g / mol to 5000 g / mol.

[0070] In some embodiments, in the polydimethylsiloxane-polybutadiene graft copolymer, the weight average molecular weight of the polybutadiene is 1000 g / mol to 5000 g / mol.

[0071] In the above embodiment, the weight average molecular weights of polyethylene glycol, polytetramethylene ether glycol, and polybutadiene are respectively within the above ranges, which can be beneficial for improving the resilience of the thermal conductive element while also achieving higher thermal conductivity.

[0072] For example, in the polydimethylsiloxane-polyethylene glycol block copolymer, the weight average molecular weight of polyethylene glycol can be, but is not limited to, 1000 g / mol, 1500 g / mol, 12000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, or a range consisting of any two of the above values.

[0073] Exemplarily, in the polydimethylsiloxane-polytetramethylene ether glycol block copolymer, the weight average molecular weight of polytetramethylene ether glycol can be, but is not limited to, 1000 g / mol, 1500 g / mol, 12000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, or a range consisting of any two of the above values.

[0074] For example, in the polydimethylsiloxane-polybutadiene graft copolymer, the weight average molecular weight of polybutadiene can be, but is not limited to, 1000 g / mol, 1500 g / mol, 12000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, or a range consisting of any two of the above values.

[0075] In some embodiments, the weight percentage of polyethylene glycol in the polydimethylsiloxane-polyethylene glycol block copolymer is 40% to 60%.

[0076] In the above embodiment, the mass ratio of ethylene glycol in the polydimethylsiloxane-polyethylene glycol block copolymer is within the above range, which can help the thermal conductive element to have both high thermal conductivity and resilience.

[0077] In some embodiments, the mass proportion of polytetramethylene ether glycol in the polydimethylsiloxane-polytetramethylene ether glycol block copolymer is 40% to 60%.

[0078] In the above embodiment, the mass ratio of polytetramethylene ether glycol in the polydimethylsiloxane-polytetramethylene ether glycol block copolymer is within the above range, which can help the thermal conductive element to have both high thermal conductivity and resilience.

[0079] In some embodiments, the grafting degree of the polydimethylsiloxane-polybutadiene graft copolymer is 5% to 15%.

[0080] In the embodiments of the present application, a coupling agent may be added to improve the compatibility of the thermally conductive filler and other organic substances.

[0081] In some embodiments, the mass fraction of the coupling agent is 0.1% to 0.3% of the mass fraction of the thermally conductive filler, that is, the mass fraction of the coupling agent is 0.8 parts to 3.6 parts.

[0082] In other embodiments, the thermally conductive filler includes a thermally conductive filler modified with a coupling agent.

[0083] It is understandable that the thermally conductive filler can be directly mixed with the coupling agent to modify its surface. This not only improves the utilization rate of the coupling agent, but also improves the compatibility of the thermally conductive filler with organic matter, thereby helping to improve the thermal conductivity, tensile strength and resilience of the thermally conductive element.

[0084] In some embodiments, the particle size of the thermally conductive filler is 0.1 μm to 150 μm.

[0085] In the above embodiment, the particle size of the thermally conductive filler is within the above range, which can help to improve the thermal conductivity of the thermally conductive element.

[0086] Furthermore, based on the total mass of the thermally conductive filler, the mass of the thermally conductive filler with a particle size greater than 80 μm and less than or equal to 150 μm accounts for 30% to 45%, the mass of the thermally conductive filler with a particle size greater than 30 μm and less than or equal to 80 μm accounts for 15% to 25%, the mass of the thermally conductive filler with a particle size greater than 5 μm and less than or equal to 30 μm accounts for 20% to 30%, the mass of the thermally conductive filler with a particle size greater than 1 μm and less than or equal to 5 μm accounts for 5% to 10%, and the mass of the thermally conductive filler with a particle size greater than or equal to 0.1 μm and less than or equal to 1 μm accounts for 1% to 10%.

[0087] In the above embodiment, the reasonable combination of the above particle sizes can further improve the thermal conductivity of the heat-conducting element, so that it has better thermal conductivity.

[0088] In some embodiments, the vinyl polysiloxane has a weight average molecular weight of 1000 g / mol to 10000 g / mol.

[0089] In some embodiments, the viscosity of the vinyl polysiloxane is 100 mPa·s to 20,000 mPa·s.

[0090] In some embodiments, the thermally conductive filler includes at least one of a metal oxide and a nitride.

[0091] Exemplarily, the thermally conductive filler may include at least one of aluminum oxide, aluminum nitride, zinc oxide, and boron nitride.

[0092] In some embodiments, the inhibitor comprises an alkynol inhibitor.

[0093] Exemplarily, the inhibitor may include at least one of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3-methyl-1-dodecyn-3-ol.

[0094] In some embodiments, the coupling agent includes a silane coupling agent.

[0095] For example, the coupling agent may include at least one of 3-aminopropyltriethoxysilane, γ-glyceroxypropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and hexadecyltriethoxysilane.

[0096] In some embodiments, the crosslinking agent includes hydrogenated silicone oil.

[0097] In some embodiments, the viscosity of the hydrogen-containing silicone oil is 100 mPa·s to 500 mPa·s.

[0098] In some embodiments, the active hydrogen in the hydrogen-containing silicone oil accounts for 0.02% to 0.4% by weight of the hydrogen-containing silicone oil.

[0099] In the above embodiment, the mass ratio of active hydrogen in the hydrogen-containing silicone oil is within the above range, which can help improve the tensile strength and resilience of the thermal conductive element.

[0100] Furthermore, the mass proportion of active hydrogen in the hydrogen-containing silicone oil is 0.05% to 0.1% of the hydrogen-containing silicone oil.

[0101] For example, the mass proportion of active hydrogen in the hydrogen-containing silicone oil can be 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.4% or a range consisting of any two of the above values.

[0102] In some embodiments, the catalyst comprises a precious metal catalyst.

[0103] Exemplarily, the catalyst includes at least one of a platinum catalyst, a rhodium catalyst, and a palladium catalyst.

[0104] In some embodiments, the catalyst may include a platinum catalyst, and the concentration of platinum in the catalyst is 2000 ppm to 5000 ppm.

[0105] In a second aspect, an embodiment of the present application provides a method for preparing a thermally conductive element according to any embodiment of the first aspect of the present application, comprising the following steps: S100, mixing raw materials of the heat conducting element to obtain a mixed raw material; S200, performing vacuum degassing, calendering and curing treatment on the mixed raw materials to obtain a thermal conductive element.

[0106] The above preparation method can not only ensure that the prepared thermal conductive element has excellent thermal conductivity, but also improve the resilience performance of the thermal conductive element.

[0107] In some embodiments, step S100 includes: S110, performing a first mixing process on the vinyl polysiloxane and the flexible copolymer to obtain a matrix; S120, performing surface modification treatment on the thermally conductive filler using a coupling agent to increase the compatibility between the thermally conductive filler and the matrix, thereby obtaining a surface-modified thermally conductive filler; S130, performing a second mixing process on the matrix, the surface-modified thermally conductive filler, the inhibitor, the cross-linking agent, and the catalyst to obtain a mixed raw material.

[0108] In the above-mentioned embodiment, blending vinyl polysiloxane with a flexible copolymer enables a more uniform dispersion of the two materials within the mixed raw materials, and the resulting thermally conductive element also exhibits improved resilience. Furthermore, surface modification of the thermally conductive filler with a coupling agent can also improve the coupling agent's utilization rate, enhance the compatibility between the conductive filler and the matrix, and allow more of the thermally conductive filler to be incorporated into the matrix, thereby increasing the thermal conductivity of the thermally conductive element.

[0109] In some embodiments, in step S110, the first mixing process is performed for 4 to 8 hours. When the first mixing process is performed within the above range, the vinyl polysiloxane and the flexible copolymer can be mixed more uniformly.

[0110] In some embodiments, in step S110 , the temperature of the first mixing process is 80° C. to 120° C. When the temperature of the first mixing process is within the above range, volatile substances in the matrix can be reduced.

[0111] In some embodiments, in step S120 , the surface modification treatment temperature is 50° C. to 80° C.

[0112] In some embodiments, in step S120 , the stirring rate of the surface modification treatment is 60 rpm / min to 120 rpm / min.

[0113] In some embodiments, in step S130 , the second mixing process is performed under a vacuum gauge pressure of -0.08 MPa to -0.10 MPa.

[0114] In some embodiments, in step S130 , the second mixing process lasts for 30 minutes to 60 minutes.

[0115] In the above embodiment, the second mixing process is performed under the above conditions, which can help remove at least part of the volatile substances.

[0116] In some embodiments, in step S200 , the vacuum gauge pressure of the vacuum defoaming treatment is -0.08 MPa to -0.10 MPa.

[0117] In some embodiments, in step S200 , the vacuum defoaming treatment time is 20 min to 60 min.

[0118] In the above embodiment, the vacuum degassing treatment is performed under the above conditions, which can make the thermal conductive element have a relatively smooth surface.

[0119] In some embodiments, in step S200 , the curing temperature is 100° C. to 150° C.

[0120] In some embodiments, in step S200 , the curing time is 15 minutes to 30 minutes.

[0121] It should be noted that the serial numbers of the steps in the method for preparing the thermal conductive element provided in this application do not imply a sequence of execution. The execution sequence of the steps should be determined by their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0122] In a third aspect, an embodiment of the present application provides an electronic device, comprising the thermal conductive element in any embodiment of the first aspect of the present application or the thermal conductive element prepared by the preparation method in any embodiment of the second aspect of the present application.

[0123] In the above embodiment, the electronic device includes the heat-conducting element in the above embodiment, and therefore, the electronic device has a good heat dissipation effect.

[0124] In some embodiments, the electronic device may be a high power density electronic device or a high voltage insulation electronic device.

[0125] Exemplarily, high power density electronic devices can be computing and data processing equipment (such as AI training chips and server CPUs, etc.), power electronics and energy equipment (such as fast charging modules and inverters, etc.), radio frequency and communication equipment (such as 5G base station radio frequency units and phased-control radars, etc.).

[0126] 1. Implementation To make the purpose, technical solutions and advantages of the examples of the present application clearer, the technical solutions in the examples of the present application will be described clearly and completely below. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0127] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0128] Example 1 This embodiment provides a method for preparing a thermally conductive element, comprising: 20 g of Vi-PDMS-Vi with a viscosity of 500 mPa·s was mixed with 20 g of PDMS-PEG (PEG with a weight-average molecular weight of 2000 g / mol and a mass fraction of 50%) in a mass ratio of 1:1 to obtain a matrix. The mixing temperature was 100° C. and the mixing time was 6 h.

[0129] 400 g of aluminum oxide with a particle size of approximately 120 μm (42.11% by mass), 200 g of aluminum oxide with a particle size of approximately 80 μm (21.05% by mass), 200 g of zinc oxide with a particle size of approximately 20 μm (21.05% by mass), 100 g of aluminum oxide with a particle size of approximately 5 μm (10.53% by mass), and 50 g of aluminum oxide with a particle size of approximately 0.2 μm (5.26% by mass) were put into a blender, and 2 g of γ-glyceryloxypropyltrimethoxysilane was added. The temperature was raised to 60°C and uniformly stirred for 24 hours. The blender speed was 100 rpm to obtain a surface-modified thermally conductive filler.

[0130] 40 g of the matrix, 952 g of the surface-modified thermally conductive filler, 0.1 g of the 1-ethynyl-1-cyclohexanol inhibitor, 2.0 g of hydrogenated silicone oil (active hydrogen is 0.08% of the mass of the hydrogenated silicone oil) and 2.5 g of the platinum catalyst were put into a vacuum mixer and stirred at a rate of 120 rpm / min to obtain a mixed raw material, wherein the vacuum gauge pressure of the stirring and mixing was approximately -0.095 MPa, and the stirring and mixing time was 45 min.

[0131] The mixed raw materials were stirred under vacuum at room temperature to remove bubbles, thereby obtaining a mixed raw material. The stirring speed was 120 rpm / min, the vacuum gauge pressure was -0.095 MPa, and the stirring time was 30 min.

[0132] The mixed raw materials were subjected to calendering and curing treatment to obtain a thermal conductive element, wherein the curing temperature was 125° C. and the curing time was 20 minutes.

[0133] Example 2 In this embodiment, except that the mass ratio of Vi-PDMS-Vi:PDMS-PEG:PDMS-PTHF (PTHF has a weight-average molecular weight of 2000 g / mol and a mass proportion of 50%) is 2:1:1, other conditions are the same as those in Example 1.

[0134] Example 3 In this example, except that the mass ratio of Vi-PDMS-Vi:PDMS-PEG is 3:1, other conditions are the same as those in Example 1.

[0135] Example 4 In this embodiment, except that the aluminum oxide with a particle size of about 120 μm is replaced with aluminum nitride with a particle size of about 120 μm, other conditions are the same as those in embodiment 1.

[0136] Example 5 In this embodiment, except for adding 200 g of aluminum nitride with a particle size of about 120 μm, other conditions are the same as those in embodiment 1.

[0137] Example 6 Except that the surface of the thermal conductive filler is not modified, other conditions in this embodiment are the same as those in Example 1.

[0138] Example 7 In this example, except that Vi-PDMS-Vi and PDMS-PEG were not premixed, other conditions were the same as those in Example 1.

[0139] Comparative Example 1 In this comparative example, except that PDMS-PEG was not added, other conditions were the same as those in Example 1.

[0140] 2. Test part The thermal conductive elements prepared in the above examples and comparative examples can be tested for their thermal conductivity, hardness, tensile strength, resilience, flame retardancy and other properties by referring to the test methods described in the following national standards. The specific methods are as follows: Thermal conductivity: Thermal conductivity is tested according to ASTM D 5470 standard; Hardness: Shore 00 hardness is tested according to ASTM D2240 standard; Tensile strength: tensile strength is tested according to ASTM D 412 standard; Elongation at break: Elongation at break is tested according to ASTM D 412 standard; Rebound performance: Rebound rate is tested according to ASTM D575-91 (2024) standard; Flame retardant performance: Flame retardant performance is tested according to UL 94 standard.

[0141] The above test results can be seen in Table 1 3. Analysis of test results of various embodiments and comparative examples The thermal conductive elements of the embodiments and comparative examples were prepared according to the above method, and their properties were measured. The results are shown in Table 1 below.

[0142] Table 1

[0143] According to Table 1, a comparison of the test results of Examples 1 to 7 and Comparative Example 1 shows that, compared to Comparative Example 1 in which the flexible copolymer of the present application is not added, the flexible copolymer is added to the matrix provided by the Examples of the present application, which enables the thermal conductive element to have both high thermal conductivity and resilience.

[0144] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

Claims

1. A heat conducting element, characterized in that: The raw materials of the thermal conductive element include, by mass: A matrix comprising 30 to 60 parts of vinyl polysiloxane and a flexible copolymer; Thermal conductive filler, 800~1200 parts; Inhibitor, 0.05 to 0.15 parts; Cross-linking agent, 1 to 8 parts; Catalyst, 2 to 6 parts; Wherein, the flexible copolymer includes a block copolymer of polysiloxane and / or a graft copolymer of polysiloxane.

2. The heat conducting element according to claim 1, characterized in that The matrix comprises a mixture of the vinyl polysiloxane and the flexible copolymer, wherein the mass ratio of the vinyl polysiloxane to the flexible copolymer is (1-4):1; Preferably, the vinyl polysiloxane comprises vinyl terminated polydimethylsiloxane; Preferably, the flexible copolymer includes at least one of a polydimethylsiloxane-polyethylene glycol block copolymer, a polydimethylsiloxane-polytetramethylene glycol block copolymer, and a polydimethylsiloxane-polybutadiene graft copolymer.

3. The heat conducting element according to claim 2, characterized in that In the polydimethylsiloxane-polyethylene glycol block copolymer, the weight average molecular weight of the polyethylene glycol is 1000 g / mol to 5000 g / mol; Preferably, the mass proportion of the polyethylene glycol in the polydimethylsiloxane-polyethylene glycol block copolymer is 40% to 60%; and / or, in the polydimethylsiloxane-polytetramethylene ether glycol block copolymer, the weight average molecular weight of the polytetramethylene ether glycol is 1000 g / mol to 5000 g / mol; Preferably, the mass proportion of the polytetramethylene ether glycol in the polydimethylsiloxane-polytetramethylene ether glycol block copolymer is 40% to 60%; and / or, in the polydimethylsiloxane-polybutadiene graft copolymer, the weight average molecular weight of the polybutadiene is 1000 g / mol to 5000 g / mol; Preferably, the grafting degree of the polydimethylsiloxane-polybutadiene graft copolymer is 5% to 15%.

4. The heat conducting element according to claim 1, characterized in that The thermally conductive filler includes a thermally conductive filler modified by a coupling agent; Preferably, the particle size of the thermally conductive filler is 0.1 μm to 150 μm; Preferably, based on the total mass of the thermally conductive filler, the mass of the thermally conductive filler having a particle size greater than 80 μm and less than or equal to 150 μm accounts for 30% to 45%; Preferably, based on the total mass of the thermally conductive filler, the mass proportion of the thermally conductive filler having a particle size greater than 30 μm and less than or equal to 80 μm is 15% to 25%; Preferably, based on the total mass of the thermally conductive filler, the mass proportion of the thermally conductive filler having a particle size greater than 5 μm and less than or equal to 30 μm is 20% to 30%; Preferably, based on the total mass of the thermally conductive filler, the mass proportion of the thermally conductive filler having a particle size greater than 1 μm and less than or equal to 5 μm is 5% to 10%; Preferably, based on the total mass of the thermally conductive filler, the mass of the thermally conductive filler having a particle size of 0.1 μm or more and 1 μm or less accounts for 1% to 10%.

5. The heat conducting element according to claim 4, characterized in that The weight average molecular weight of the vinyl polysiloxane is 1000 g / mol to 10000 g / mol; preferably, the viscosity of the vinyl polysiloxane is 100 mPa·s to 20000 mPa·s; and / or, the thermally conductive filler comprises at least one of a metal oxide and a nitride; and / or, the inhibitor comprises an alkynol inhibitor; and / or, the coupling agent comprises a silane coupling agent; and / or, the cross-linking agent comprises hydrogen-containing silicone oil; And / or, the catalyst comprises a noble metal catalyst.

6. The heat conducting element according to claim 5, characterized in that The thermally conductive filler comprises at least one of aluminum oxide, aluminum nitride, zinc oxide and boron nitride; and / or, the inhibitor comprises at least one of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3-methyl-1-dodecyn-3-ol; and / or, the coupling agent comprises at least one of 3-aminopropyltriethoxysilane, γ-glyceroxypropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and hexadecyltriethoxysilane; And / or, the viscosity of the hydrogen-containing silicone oil is 100 mPa·s to 500 mPa·s; preferably, the mass proportion of active hydrogen in the hydrogen-containing silicone oil is 0.02% to 0.4% of the hydrogen-containing silicone oil; And / or, the catalyst includes at least one of a platinum catalyst, a rhodium catalyst and a palladium catalyst.

7. A method for preparing a thermally conductive element according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mixing the raw materials of the heat conducting element to obtain a mixed raw material; The mixed raw material is subjected to vacuum degassing, calendering and curing treatment to obtain the thermal conductive element.

8. The preparation method according to claim 7, characterized in that The step of mixing the raw materials of the heat conducting element to obtain the mixed raw materials comprises the following steps: Performing a first mixing process on the vinyl polysiloxane and the flexible copolymer to obtain a matrix; Using a coupling agent to perform surface modification treatment on the thermally conductive filler to increase the compatibility between the thermally conductive filler and the matrix, thereby obtaining a surface-modified thermally conductive filler; The matrix, the surface-modified thermally conductive filler, the inhibitor, the cross-linking agent and the catalyst are subjected to a second mixing process to obtain the mixed raw material.

9. The preparation method according to claim 8, characterized in that The time of the first mixing treatment is 4h~8h; And / or, the temperature of the first mixing treatment is 80°C to 120°C; And / or, the surface modification treatment temperature is 50°C to 80°C; And / or, the stirring rate of the surface modification treatment is 60 rpm / min to 120 rpm / min; And / or, the second mixing process is performed under a vacuum gauge pressure of -0.08 MPa to -0.10 MPa; And / or, the treatment time of the second mixing treatment is 30 min to 60 min; And / or, the vacuum gauge pressure of the vacuum degassing treatment is -0.08 MPa to -0.10 MPa; And / or, the vacuum defoaming treatment time is 20min~60min; And / or, the curing temperature is 100° C. to 150° C.; And / or, the curing treatment time is 15 minutes to 30 minutes.

10. An electronic device, characterized in that: The invention comprises the thermal conductive element according to any one of claims 1 to 6 or the thermal conductive element prepared by the preparation method according to any one of claims 7 to 9.

Images