Heat sink and manufacturing method and application thereof

Abstract

The invention provides a heat sink and a manufacturing method and application thereof, and relates to the technical field of metal heat dissipation materials. The heat sink comprises a metal base material, a metal cover plate and longitudinal heat-conducting fins embedded in the metal base material. The longitudinal heat-conducting fin is used as an inner core, the metal base material and the metal cover plate form a metal shell to wrap the longitudinal heat-conducting fin, and the longitudinal heat-conducting fin is tightly attached to the metal base material and the metal cover plate to form an integral structure; and the longitudinal heat-conducting fins are graphene heat-conducting materials formed by compounding resin and graphene. According to the invention, the graphene heat-conducting material is wrapped in the metal in an embedded manner, and the longitudinal heat-conducting property of the graphene heat-conducting material is utilized to directly promote the conduction of heat from the bottom of the heat sink to the fins, so that the heat at the bottom of the heat sink has obvious advantages in diffusion speed along the direction of the graphene layer; and the heat can be quickly diffused to the two sides of the heat sink, so that the heat can be distributed to more fins, and the heat dissipation is accelerated.

Description

Technical Field

[0001] The present invention relates to the technical field of metal heat dissipation materials, and in particular to a heat sink and a manufacturing method and application thereof. Background Art

[0002] Metal materials are widely used in the field of heat conduction, mainly based on their superior thermal conductivity in electronic devices, such as computer CPUs, graphics processing units (GPUs), power supplies, etc. Traditional metal thermal conductive materials, such as aluminum, copper, silver, etc., are the most commonly used heat dissipation materials, usually made into heat sinks, heat pipes and radiators, which effectively transfer the heat generated by the chip and keep the equipment running stably. With the advancement of science and technology, electronic devices are increasingly pursuing small and precise spatial dimensions, which makes the heat generated by electronic devices per unit volume increase rapidly, and the requirements for heat dissipation devices continue to increase, especially in the field of microelectronics and communication technology. The high frequency, high speed and large-scale integrated circuits are dense and miniaturized, resulting in more and more concentrated heat energy generated inside the equipment. Heat conduction and heat dissipation issues have become the key to restricting the development of many fields. Traditional metal thermal conductive materials have limitations such as high density, easy oxidation, low specific thermal conductivity (ratio of thermal conductivity to volume density), and high coefficient of thermal expansion (CTE). It is difficult to meet the growing heat dissipation needs of electronic devices in the current microelectronics field.

[0003] The heat sink is an important part of thermal management. It mainly conducts away the heat generated by the chip quickly to ensure the normal operation of the core components. In addition to requiring the heat sink material to have a low thermal expansion coefficient that matches the chip in the direction parallel to the chip plane, it also needs to have a high thermal conductivity in the direction perpendicular to the chip plane. In addition, since the equipment is also faced with harsh service environments such as large impacts and high-frequency vibrations during service, the heat sink material also needs to have sufficient strength.

[0004] In recent years, graphite has been increasingly used in heat dissipation fields such as 3C products, high-power multi-chip modules, and CT machine X-ray tubes. Heat dissipation has become a bottleneck restricting the development and application of high-power devices. Therefore, the heat sink material is a thermally conductive graphite sheet with higher heat dissipation capacity and lower density, and is connected with metal structural materials. This is an ideal solution to solve the heat dissipation problem of high-power electronic device packaging.

[0005] However, there are also defects in combining thermally conductive graphite sheets with heat sinks. For example, it is difficult to avoid the interface reaction between the Al base and the carbon reinforcement during the preparation process at a relatively high temperature, and the interface reaction products of Al4C3 are also harmful to TC and mechanical properties. In addition, Al4C3 is prone to hydrolysis in a humid atmosphere, which seriously threatens the safety of composite applications; there are technical problems such as poor wettability, weak interface bonding, severe interface reaction, and high interface thermal resistance between the Al base and the carbon reinforcement. Therefore, in order to reduce the problem of interface reaction between the Al base and the thermally conductive graphite sheet, TiC, WC or silicon carbide coating is usually applied to the carbon base surface to improve the carbon-metal interface. However, the application of coating TiC, WC or silicon carbide coating is generally in the laboratory stage and is not suitable for widespread use. It is difficult to industrialize, so we need to select solder commonly used in the market to isolate the Al base and the graphite sheet. For another example, there is a large amount of air between the metal shell and the graphene layer, which will seriously affect the thermal conductivity, resulting in the thermal conductive graphene sheet not having an obvious enhancement effect on thermal conductivity, and the overall strength is prone to defects. At the same time, the pure metal radiator in current technology has the advantages of good heat dissipation effect and fast heat dissipation, but its heat diffusion is isotropic and presents uniform divergence, that is, the thermal conductivity effect in all directions is the same, which causes the temperature of the heat source to diffuse and transmit in all directions through the radiator. When the fins at the center point dissipate heat outward, neither the upward heat diffusion nor the utilization rate of the fins at the edge can be fully utilized. Obviously, how to improve the utilization rate of the edge fins is an important way to improve the heat dissipation efficiency of the radiator.

[0006] Based on the problems existing in the prior art, the present invention proposes a heat sink and its manufacturing method and application, which utilizes the isotropic characteristics of metal heat dissipation and conducts heat in a directional manner through a vertical graphite structure to quickly transfer the heat of the inner core to all the fins. In particular, the fins at the edge can also be quickly heated and dissipated, thereby giving full play to the heat dissipation effect of the heat sink and improving the utilization rate of the radiator. Summary of the invention

[0007] In order to overcome the above-mentioned deficiencies of the prior art, an object of the present invention is to provide a heat sink and a manufacturing method and application thereof.

[0008] To achieve the above objectives, the present invention provides the following technical solutions.

[0009] One aspect of the present invention provides a heat sink, comprising: a metal base material, a metal cover plate, and a longitudinal heat conductive sheet embedded in the metal base material; the longitudinal heat conductive sheet serves as an inner core, the metal base material and the metal cover plate form a metal shell to wrap the longitudinal heat conductive sheet inside, and the longitudinal heat conductive sheet is tightly fitted to the metal base material and the metal cover plate to form an integral structure.

[0010] Preferably, the material of the longitudinal heat conductive sheet is a graphene composite material.

[0011] More preferably, the material of the longitudinal heat conductive sheet is a graphene composite material composed of resin and graphene.

[0012] Preferably, the graphene composite material is formed by cyclically alternatingly stacking multiple resin layers and multiple graphene heat-conducting layers.

[0013] Preferably, the extending direction of the graphene layer in the graphene heat conductive layer is consistent with the heat diffusion direction of the longitudinal heat conductive sheet.

[0014] Preferably, the metal matrix material is any one of silver, copper, aluminum, tungsten and diamond.

[0015] Preferably, the metal base material is the same as the metal cover plate material.

[0016] As one aspect of the invention, the present invention also provides a fin-type heat sink, comprising fins, a metal base material perpendicular to the fins, a metal cover plate, and a longitudinal heat conductive sheet embedded in the metal base material. The longitudinal heat conductive sheet serves as an inner core, the metal base material and the metal cover plate form a metal shell to wrap the longitudinal heat conductive sheet inside, and the longitudinal heat conductive sheet is tightly fitted with the metal base material and the metal cover plate to form an integral structure; the metal base material and the fin are an integral structure.

[0017] As one of the objects of the invention, the present invention also provides a method for manufacturing a heat sink as described above, wherein the longitudinal heat conductive sheet is embedded in the metal base material by snap-fitting and packaged with a metal cover plate, and the metal cover plate, the longitudinal heat conductive sheet and the metal base material are combined together by hot pressing and welding to form an integral structure, thereby obtaining the heat sink.

[0018] As a preferred embodiment, the specific steps of the method for manufacturing the heat sink include:

[0019] S1. Providing the metal matrix material;

[0020] S2. A groove is formed at one end of the metal base material;

[0021] S3. The longitudinal heat conductive sheet is embedded in the groove, and the size of the longitudinal heat conductive sheet matches the size of the groove;

[0022] S4. The metal cover is bonded to the surface of the longitudinal heat conductive sheet and the metal base material;

[0023] S5. The metal cover plate and the metal base material are formed into an integral structure through hot pressing and welding to obtain the heat sink.

[0024] As a preferred implementation, fins are made at the other end of the metal base material to obtain a fin-type heat sink.

[0025] The specific manufacturing method includes: after S5 of the above technical solution, manufacturing a fin at the other end of the metal base material, wherein the fin is perpendicular to the metal base material. The manufacturing method of the fin can adopt the existing method in the prior art, and the present invention does not make specific restrictions, and the method that can be implemented, such as cutting and grinding, etc., all belong to the protection scope of the present invention.

[0026] As a preferred embodiment, the groove is a trapezoidal groove; the trapezoidal groove includes a first notch and a second notch; the size of the second notch is larger than the size of the first notch.

[0027] Preferably, the size of the longitudinal heat conductive sheet matches the size of the first notch; and the size of the metal cover plate matches the size of the second notch.

[0028] Preferably, the thickness of the metal cover plate is 0.5-1.5 mm.

[0029] Preferably, the thickness of the longitudinal heat conductive sheet is 3-4 mm.

[0030] Preferably, the distance between the longitudinal heat conductive sheet and the fin is 0.5-1 mm. It should be noted that the distance specifically refers to the vertical distance between the longitudinal heat conductive sheet and the root of the fin.

[0031] As another preferred implementation, the groove may also be a single groove; and the size of the graphene layer matches the size of the single groove.

[0032] Preferably, the size of the metal cover plate matches that of the metal base material.

[0033] Preferably, the hot pressing conditions include: raising the temperature to 140-170° C., under a pressure of 10-15 kg, and then naturally cooling the temperature to room temperature.

[0034] Preferably, the welding is any one of brazing, vacuum diffusion welding and laser welding.

[0035] Preferably, the welding is performed to weld the gap between the metal cover plate and the metal base material so that the two are tightly and seamlessly combined.

[0036] Preferably, after the welding is completed, a grinding and polishing process is further included to make the surface of the heat sink smooth and flat.

[0037] As a preferred implementation, solder is added between the metal cover plate and the longitudinal heat conductive sheet, and between the longitudinal heat conductive sheet and the metal base material, and the solder covers the longitudinal heat conductive sheet.

[0038] Preferably, the solder is at least one of AlSiMg, silver-based and copper-based solders.

[0039] Preferably, an adhesive layer is coated between the metal cover plate and the longitudinal heat conductive sheet, and between the longitudinal heat conductive sheet and the metal base material to fill the gaps between the metal cover plate, the graphene layer and the metal base material.

[0040] Preferably, the coating amount of the adhesive layer is 0.025-0.04 g / cm 2 .

[0041] Preferably, the adhesive layer is thermally conductive glue or paraffin.

[0042] Preferably, the thermally conductive adhesive is any one of silicone glue, epoxy resin glue and acrylate glue.

[0043] The heat sink provided by the above technical solution can be used to prepare a radiator with a longitudinal heat conductive sheet; the longitudinal heat conductive sheet is a graphene composite material with the function of rapid longitudinal heat conduction, so that the heat can be quickly diffused to both sides along the longitudinal direction, so that more fins can be heated quickly, accelerating the dissipation of heat, and improving the heat dissipation speed and heat dissipation efficiency of the radiator.

[0044] The technical effects of the technical solution of the present invention are as follows:

[0045] The technical solution of the present invention,

[0046] 1. The present invention wraps the graphene composite material inside the metal material by means of a clamping method, and at the same time utilizes the longitudinal thermal conductivity of the graphene composite material, so that the diffusion speed of the heat at the bottom of the heat sink along the extension direction of the graphene layer has obvious advantages, so that the heat at the bottom can be quickly diffused to both sides of the heat sink, and the heat can be quickly diffused to more fins, especially the fins at the edge can also be quickly heated, thereby realizing accelerated heat dissipation and improving the heat dissipation speed and heat dissipation efficiency of the radiator.

[0047] 2. The present invention adopts the method of coating thermally conductive adhesive or paraffin between each layer. On the one hand, the air inside the heat sink structure is reduced as much as possible by filling the gaps between the materials. On the other hand, the thermally conductive adhesive or paraffin also has a certain bonding effect, thereby enhancing the bonding strength between the materials inside the thermal layer. Moreover, the metal cover plate of the upper layer and the graphene composite material of the middle layer are initially bonded together through the melting and solidification process of the wax or thermally conductive adhesive, which enables the metal cover plate to be more evenly fitted with a metal base material of a certain mass, thereby forming an overall structure, which is more conducive to the diffusion of heat.

[0048] 3. The present invention uses a method of adding solder between the metal cover plate and the metal base material, and between the graphene composite material and the metal cover plate, and combines it with a low-temperature hot pressing method to make the upper metal cover plate and the metal base material, and the metal base material and the graphene composite material in close contact, and the hot pressing excludes the air layer as much as possible, and then uses the welding bonding technology in combination to melt part of the metal solder between the layers and between the layers and the base material, thereby improving the bonding strength between the layers, connecting the upper metal cover plate and the lower metal base material to form an integral structure, thereby obtaining a heat sink with a complete and tight structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic diagram of the structure of the metal base material clamping the graphene layer and the metal cover plate in Example 1 of the present invention.

[0050] Figure 2 This is a schematic diagram of the structure of the heat sink manufactured in Example 1 of the present invention.

[0051] Figure 3 Schematic diagram of ICEPAK thermal simulation of the heat sink of Example 1 of the present invention.

[0052] Figure 4 Schematic diagram of ICEPAK thermal simulation of the heat sink of comparative example 1 of the present invention.

[0053] Figure 5 This is a schematic diagram of the dual-point temperature of the aluminum heat sink with a graphene core according to Example 1 of the present invention.

[0054] Figure 6 Schematic diagram of the bottom anisotropic temperature of an aluminum heat sink with a graphene core according to Example 1 of the present invention.

[0055] Figure 7 Schematic diagram of the dual-point temperature of the pure aluminum heat sink of comparative example 1 of the present invention.

[0056] Figure 8 This is a real photo of the fin-type heat sink provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0057] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0058] The disclosures of all patent and non-patent literature cited herein are incorporated herein by reference in their entirety.

[0059] As used in the invention, the terms "comprises," "includes," "contains," "covers," "has," "with," or any other variation thereof are intended to cover non-exclusive inclusions. For example, a process, method, article, or apparatus that includes a list of elements need not be limited to only those elements, but may include other elements that are not explicitly listed or that are inherent to the process, method, article, or apparatus. In addition, unless expressly indicated to the contrary, "or" refers to an inclusive "or" rather than an exclusive "or." For example, conditions A or B satisfy any of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist). The phrase "one or more" is intended to cover non-exclusive inclusions. For example, one or more of A, B, and C, means any of the following: A alone, B alone, C alone, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C.

[0060] In addition, "a" or "an" is used to describe the elements and components described herein. This is done not only for convenience but also to provide a general sense of the scope of the invention. This description should be understood to include one or at least one, one or at least one, and the singular also includes the plural, unless it is obvious that it is intended otherwise.

[0061] The present invention provides a heat sink, which mainly comprises a metal base material, a graphene layer embedded in the metal base material, and a metal cover plate for encapsulating the graphene layer.

[0062] The present invention also provides a fin-type heat sink, comprising fins, and a metal base material vertically arranged with the fins, a graphene layer embedded in the metal base material, and a metal cover plate for encapsulating the graphene layer; the fins and the metal base material are an integrated structure.

[0063] It should be noted that the preparation method of the fin is a prior art. For example, the method for making the fin includes placing a metal base material into a punch press, processing it through a stamping die, forming the shape of the fin, and then grinding and polishing it. Other methods for making the fin are subject to being achievable and are not specifically limited here; combined with the heat sink manufacturing method of the present invention, the method for making the fin all fall within the scope of protection of this case.

[0064] As another preferred embodiment, the fins and the metal base material are not an integrated structure. After the heat sink is prepared, the fins can be connected to the metal base material through extrusion, welding and other methods using existing technologies. The specific connection method is subject to what can be achieved and is not specifically limited here. Combined with the heat sink manufacturing method of the present invention, the fin connection method all falls within the scope of protection of this case.

[0065] The metal cover plate and the metal base are made of the same material.

[0066] The metal cover plate and the metal base are made of silver, copper, aluminum, tungsten, diamond and other metal materials.

[0067] The material of the graphene layer is a longitudinal heat-conducting sheet made of longitudinal heat-conducting graphene in Chinese invention patent CN2023116173993, which is a graphene composite material. The material of the graphene layer is formed by cyclic alternating stacking of multiple resin layers and multiple graphene heat-conducting layers; the extension direction of the graphene in the graphene heat-conducting layer is consistent with the heat diffusion direction of the longitudinal heat-conducting sheet. It should be specially noted that the entire content of the applied Chinese invention patent CN2023116173993 belongs to the invention content disclosed in this case.

[0068] In some specific embodiments, the length and width of the metal base material of the heat sink are 80 mm*80 mm.

[0069] In some specific embodiments, the sheet length is 27 mm, the overall thickness of the metal base material, the graphene layer, and the metal cover plate is 5 mm, and a single groove or a stepped groove is provided in the metal base material.

[0070] In some specific embodiments, when the metal base material is provided with a single groove, the length and width of the single groove are 75*75 mm, the thickness of the metal base material ranges from 4 to 4.5 mm, the height of the single groove is 3 to 4 mm, the thickness of the metal cover plate is 0.5 to 1 mm, and the single groove is used to place the graphene layer, and the graphene layer can be just stuck in the groove.

[0071] As a preferred embodiment, when the thickness of the metal base material is 4mm, the height of the single groove is 3mm, the thickness of the metal cover plate is 1mm, the thickness of the metal layer between the inner core and the fin is 1mm, the thickness of the metal cover plate is also relatively large, and the overall thermal conductivity will be a little weaker, but the strength will be higher). When the thickness of the metal base material is 4.5mm, the height of the single groove is 4mm, the thickness of the metal cover plate is 0.5mm, the thickness of the metal layer between the inner core and the fin is only 0.5mm, and the thickness of the metal cover plate is also relatively small. The overall thermal conductivity will be better, but the relative strength will be lower.

[0072] In some specific embodiments, when the metal base material is provided with a stepped groove, in the stepped groove, the length and width of the large groove is 75*75mm, and the small groove is 70*70mm; the thickness of the large groove is in the range of 0.5 to 1.5mm, and the thickness of the small groove is 3N4mm. The large groove is used to clamp the metal cover plate and has the same length, width and thickness as the large groove. The small groove is used to clamp the graphene layer and has the same length, width and thickness as the small groove. The three are wrapped to form a complete heat sink structure, keeping the overall thickness of the heat sink at 5mm.

[0073] Compared with the technical solution of opening a single groove, the inner core (graphene layer) embedded in the stepped groove is smaller in size, and the relative thermal conductivity will be reduced; however, the graphene layer and the metal matrix material can be more closely combined, so in terms of the strength of the overall heat sink, the opening of the matrix groove will improve it.

[0074] In some specific embodiments, liquid substances with certain adhesiveness, such as thermal conductive glue and paraffin, are to be coated between the metal base material and the graphene layer, and between the metal cover plate and the graphene layer. On the one hand, the air between the layers of materials inside the heat sink can be reduced as much as possible; on the other hand, the adhesive effect of the thermal conductive glue and paraffin can enhance the bonding strength between the blocks. The type of thermal conductive glue can be selected from silicone, epoxy resin glue, and acrylate glue. The coating amount of the thermal conductive glue and paraffin is about 0.025-0.04 g / cm 2 .

[0075] In some specific embodiments, the metal cover is covered on the graphene layer coated with thermal conductive glue or wax, and then hot-pressed with 10-15 kg of metal matrix material at 140-170° C. until the metal matrix material is naturally cooled to room temperature and then removed. The purpose of this step is mainly to make the metal cover and the graphene layer initially bonded together through the melting and solidification process of the wax, and the heavy metal matrix material can also make the metal cover more flat and fit.

[0076] In some specific embodiments, based on the good bonding between the graphene layer, the metal cover plate and the metal base material, laser welding is used to tightly weld the gap between the metal cover plate and the metal base material, and then the surface of the structure is ground and polished. At this point, the heat sink is completed.

[0077] In some specific embodiments, solder can also be added between the metal base material and the graphene layer, and between the metal cover plate and the graphene layer until the graphene layer is just covered. On the one hand, the presence of air between the layers of materials can be reduced as much as possible. On the other hand, the metal solder has a stronger thermal conductivity than thermal conductive glue, wax and other materials, which can greatly reduce the air thermal resistance. The fine metal solder can enter the gap of the graphene layer, and can fill the air gap between the graphene block and the upper metal base material to a great extent, reducing the impact of the air thermal resistance. The solder can be selected as AlSiMg, silver-based, or copper-based solder.

[0078] In some specific embodiments, the upper metal cover plate is closely contacted with the metal base material and the graphene layer by low-temperature hot pressing, and the air layer is excluded as much as possible, and then the metal cover plate is connected with the metal base material by combining brazing, vacuum diffusion welding, laser welding and other technologies (this step can melt the metal brazing material between the layers of materials, which helps to improve the bonding force between the internal structures of the metal base material) to form a heat sink with a complete and tight structure. Then the entire surface of the heat sink is ground and polished, and the heat sink is completed.

[0079] Unless otherwise defined, the meaning of all technical and scientific terms used herein is the same as that generally understood by those of ordinary skill in the art to which the present disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosed composition embodiments, suitable methods and materials are described below. Unless citing a specific paragraph, all publications, patent applications, patents and other references mentioned herein are incorporated herein by reference in their entirety. If a conflict occurs, this specification and the definitions included therein shall prevail. In addition, materials, methods and examples are illustrative only, and not restrictive.

[0080] The technical scheme of the present invention, its implementation process and principle, etc. will be further explained through specific embodiments as follows. It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. The described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Unless otherwise specified, the reagents and raw materials used in the following examples are commercially available, and the test methods for which specific conditions are not specified are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers. In addition, unless otherwise specified, the experimental methods, detection methods, and preparation methods disclosed in the present invention all adopt conventional techniques in the art. These technologies have been fully described in the existing literature.

[0081] The technical solution of the present invention is described in detail below through specific embodiments.

[0082] Example 1

[0083] The present embodiment provides a heat sink, which is a high-efficiency radiator with a graphene inner core. The heat sink includes fins and a metal base material that is an integral structure with the fins. The metal base material is embedded with a graphene layer and a metal cover plate. The graphene layer serves as the inner core. The metal base material and the metal cover plate tightly wrap the graphene layer inside the metal base material. The metal base material, the graphene layer and the metal cover plate form an integral structure.

[0084] The graphene layer and the fins are vertically arranged at both ends of the metal base material; the material of the graphene layer is a longitudinal heat conductor, and the heat diffusion direction is along the longitudinal direction, while the heat diffusion direction of the fins arranged vertically to the graphene layer is along the transverse direction; the metal base material and the fins are an integrated structure. When the graphene layer is formed, the heat can be quickly diffused to the vertical and adjacent fins, and the heat can be diffused longitudinally to more fins, and the fins diffuse the heat along the direction in which the fins extend, thereby achieving rapid and uniform diffusion of heat in both the transverse and longitudinal directions, thereby improving the effectiveness of heat diffusion.

[0085] In detail, a groove is opened at one end of the metal base material and the graphene layer is filled in the groove by a clip-on method, and then the metal cover plate is used for packaging to seal the graphene layer in the metal base material, completing the wrapping of the graphene layer by the metal base material and the metal cover plate to form an overall structure.

[0086] In this embodiment, the material used for the graphene layer is a graphene longitudinal heat conductor, including a cyclically stacked resin layer and a graphene heat conducting layer, and the resin layer and the graphene heat conducting layer are tightly combined; the extension direction of the graphene layer in the graphene heat conducting layer is consistent with the heat conducting direction of the graphene longitudinal heat conductor; the graphene heat conducting layer includes a plurality of first graphene sublayers stacked in sequence and a second graphene sublayer is arranged between any two of the first graphene sublayers, wherein the first graphene sublayer is formed by graphitizing a graphene oxide film; the first graphene sublayer and the second graphene sublayer are tightly combined; a resin layer is arranged between the first graphene sublayer and the second graphene sublayer, the graphene heat conducting layer and the resin layer are cyclically alternated and stacked, and a plurality of resin layers and a plurality of graphene heat conducting layers are overlapped in this way to form a graphene composite material, that is, a graphene longitudinal heat conductor or a longitudinal heat conducting sheet.

[0087] Specifically, the preparation method of the above-mentioned inner core material refers to Example 1 of CN1 17507504A.

[0088] Furthermore, the fins, metal base material and metal cover plate are all made of aluminum metal. The graphene layer and the metal cover plate are embedded in the end side of the metal base material by snap-fitting, and the fins on the opposite side are vertically arranged to the graphene layer and the metal cover plate; the metal base material and the fins are an integrated structure.

[0089] The dimensions of the metal base material are: length*width*thickness: 80mm*80mm*5mm, and the length of the fin is 27mm.

[0090] The heat sink is a multi-layer structure consisting of fins, a bottom metal layer, a graphene layer and a metal cover plate, and the graphene layer and the metal cover plate are fixed inside the bottom metal base material by clamping to form an integral structure.

[0091] The specific preparation steps include:

[0092] See also Figure 1 First, an aluminum metal matrix material is provided as a metal base material 1, and a length*width*thickness of 80mm*80mm*5mm is reserved at one end of the metal base material as a bottom metal layer 4, and a fin portion 5 is reserved at the other end for making fins. In order to facilitate the subsequent hot pressing and welding process, this embodiment preferably chooses to embed the graphene layer and the encapsulation metal cover plate first, and then make the cover plate;

[0093] Then, the heat sink is obtained by integrating the graphene layer and the metal cover plate into the metal base material and then making fins on the opposite side.

[0094] Furthermore, in the method of integrating the metal base material, the graphene layer and the metal cover plate, the metal base material 1 is provided with a stepped groove along the surface of the thickness side wall; the stepped groove comprises a large groove 3 in an upper layer and a small groove 2 in a lower layer, wherein the present invention provides a preferred implementation manner, wherein the dimensions of the large groove selected in this embodiment are: length*width*thickness is 75mm*75mm*1mm, and the dimensions of the small groove are: length*width*thickness is 70mm*70mm*3mm.

[0095] The small groove 2 is used to clamp the graphene layer, and the length, width and thickness of the graphene layer match the size of the small groove, and the size of the graphene layer is 70*70*3mm; the large groove is used to clamp the metal cover plate, and the length, width and thickness of the metal cover plate match the groove size of the large groove, and the size of the metal cover plate is 75*75*1mm.

[0096] The graphene layer is inserted into the small groove along the longitudinal direction, and then the metal cover plate is inserted into the groove along the longitudinal direction of the large groove. The graphene layer and the metal cover plate are embedded in the stepped groove of the metal base material in turn. The three are wrapped to form a complete heat sink structure, and the overall thickness of the heat sink is kept at 5mm.

[0097] As a preferred embodiment, the fins are made by reserving a fin portion 5 at the opposite end of the metal base material where the groove is opened, and a buffer portion 7 is provided between the fin and the graphene layer (inner core) for transition between the longitudinal heat conduction of the graphene layer and the longitudinal heat conduction of the fin.

[0098] As a preferred embodiment, paraffin wax can be coated between the metal substrate material and the graphene layer, and between the metal cover plate and the graphene layer, with a coating amount of 0.031 g / cm 2 ; Cover the metal cover plate on the paraffin-coated graphene layer. After the assembly is completed, hot press 13.45 kg of metal matrix material at 170°C, and remove it after the metal matrix material naturally cools to room temperature, completing the hot pressing process.

[0099] As a preferred embodiment, after the metal base material and the graphene layer, and the metal cover plate and the graphene layer are bonded, laser welding can be used to tightly weld the gap between the metal cover plate and the metal base material, and then grinding and polishing are performed.

[0100] Finally, see Figure 2 , fins are made on the opposite side of the metal base material relative to the stepped groove. At this point, a fin-type heat sink is prepared.

[0101] Specifically, see Figure 8, which is a real photo of the fin-type heat sink provided in this embodiment, shows that the metal base material and the fin are an integrated structure, the length of each single fin is 27mm, the thickness is 0.8mm, the total number of fins is 26, and the thickness of the buffer portion 7 between the inner core and the fin is 1mm.

[0102] Example 2

[0103] This embodiment provides a heat sink, the structure and materials of which are the same as those of Embodiment 1, except that the sizes of the graphene layer and the metal cover plate are different.

[0104] The specific preparation steps include:

[0105] An aluminum metal base material is provided, and a length*width*thickness of 80mm*80mm*5mm is reserved on one side of the metal base material as a bottom metal layer, and the other side opposite thereto is used for making fins.

[0106] The heat sink is obtained by integrating a graphene layer and a metal cover plate onto a metal base material and then cutting fins on opposite sides.

[0107] Specifically, the method of integrating the metal substrate material, the graphene layer and the metal cover plate, see Figure 1 The metal base material has stepped grooves along the surface of the thickness side wall; the stepped grooves include large grooves on the upper layer and small grooves on the lower layer. As a preferred implementation, the size of the large groove selected in this embodiment is: length*width*thickness is 75mm*75mm*0.5mm, and the size of the small groove is: length*width*thickness is 70mm*70mm*4mm.

[0108] The small groove is used to clamp the graphene layer, and the length, width and thickness of the graphene layer match the size of the small groove, and the size of the graphene layer is 70*70*4mm; the large groove is used to clamp the metal cover plate, and the length, width and thickness of the metal cover plate match the groove size of the large groove, and the size of the metal cover plate is 75*75*0.5mm.

[0109] The graphene layer is inserted into the small groove along the longitudinal direction, and then the metal cover plate is inserted into the groove along the longitudinal direction of the large groove. The graphene layer and the metal cover plate are embedded in the stepped groove of the metal base material in turn. The three are wrapped to form a complete heat sink structure, and the overall thickness of the heat sink is kept at 5mm.

[0110] As a preferred embodiment, an adhesive can be applied between the metal base material and the graphene layer, and between the metal cover plate and the graphene layer. The adhesive is paraffin wax, and the coating amount of the paraffin wax is 0.031 g / cm 2 ; Cover the metal cover plate on the paraffin-coated graphene layer. After the assembly is completed, hot press 13.45 kg of metal matrix material at 170°C until the metal matrix material naturally cools to room temperature and then is removed.

[0111] As a preferred embodiment, after the metal base material and the graphene layer, and the metal cover plate and the graphene layer are bonded, laser welding can be used to weld the gap between the metal cover plate and the metal base material tightly, and then the whole is ground and polished.

[0112] As a preferred embodiment, fins are prepared on the opposite side of the metal base material relative to the stepped groove. The fin length is 27 mm, the thickness is 0.8 mm, the total number of fins is 26, and the thickness of the buffer portion 7 between the inner core and the fin is 0.5 mm. At this point, a fin-type heat sink with an integral structure is completed.

[0113] Example 3

[0114] This embodiment provides a heat sink, the structure and materials of which are the same as those of Embodiment 1, except that the sizes of the graphene layer and the metal cover plate are different.

[0115] Specifically, in this embodiment, the metal base material has stepped grooves along the surface of the thickness side wall; the stepped grooves include large grooves on the upper layer and small grooves on the bottom layer, wherein, as a preferred embodiment, the dimensions of the large grooves selected in this embodiment are: length*width*thickness is 75mm*75mm*1.5mm, and the dimensions of the small grooves are: length*width*thickness is 70mm*70mm*3mm.

[0116] The small groove is used to clamp the graphene layer, and the length, width and thickness of the graphene layer match the size of the small groove, and the size of the graphene layer is 70*70*3mm; the large groove is used to clamp the metal cover plate, and the length, width and thickness of the metal cover plate match the groove size of the large groove, and the size of the metal cover plate is 75*75*1.5mm.

[0117] The graphene layer is inserted into the small groove along the longitudinal direction, and then the metal cover plate is inserted into the groove along the longitudinal direction of the large groove. The graphene layer and the metal cover plate are embedded in the stepped groove of the metal base material in turn. The three are wrapped to form a complete heat sink structure, and the overall thickness of the heat sink is kept at 5mm.

[0118] As a preferred embodiment, an adhesive can be applied between the metal base material and the graphene layer, and between the metal cover plate and the graphene layer. The adhesive is paraffin wax, and the coating amount of the paraffin wax is 0.031 g / cm 2 ; Cover the metal cover plate on the paraffin-coated graphene layer. After the assembly is completed, hot press 13.45 kg of metal matrix material at 170°C until the metal matrix material naturally cools to room temperature and then is removed.

[0119] As a preferred embodiment, after the metal base material and the graphene layer, and the metal cover plate and the graphene layer are bonded, laser welding can be used to weld the gap between the metal cover plate and the metal base material tightly, and then the whole is ground and polished.

[0120] Finally, fins are made on the opposite side of the metal base material relative to the stepped groove. The fin length is 27 mm, the thickness is 0.8 mm, the total number of fins is 26, and the thickness of the buffer part 7 between the inner core and the fin is 0.5 mm. At this point, a fin-type heat sink is prepared.

[0121] Example 4

[0122] The heat sink provided in this embodiment has the same structure as that of Embodiment 1, and the only difference is the size of the graphene layer and the metal cover plate.

[0123] Specifically, in this embodiment, the metal base material has stepped grooves along the surface of the thickness side wall; the stepped grooves include large grooves on the upper layer and small grooves on the bottom layer. Among them, as a preferred embodiment, the dimensions of the large grooves selected in this embodiment are: length*width*thickness is 75mm*75mm*1mm, and the dimensions of the small grooves are: length*width*thickness is 70mm*70mm*3.5mm.

[0124] The small groove is used to clamp the graphene layer, and the length, width and thickness of the graphene layer match the size of the small groove, and the size of the graphene layer is 70*70*3.5mm; the large groove is used to clamp the metal cover plate, and the length, width and thickness of the metal cover plate match the groove size of the large groove, and the size of the metal cover plate is 75*75*1mm.

[0125] The graphene layer is inserted into the small groove along the longitudinal direction, and then the metal cover plate is inserted into the groove along the longitudinal direction of the large groove. The graphene layer and the metal cover plate are sequentially embedded in the stepped groove of the metal base material. The three are wrapped to form an integral structure, and the overall thickness is maintained at 5mm.

[0126] As a preferred embodiment, paraffin wax can be coated between the metal substrate material and the graphene layer, and between the metal cover plate and the graphene layer. The coating amount of the paraffin wax is 0.031 g / cm 2 ; Cover the metal cover plate on the paraffin-coated graphene layer. After the assembly is completed, hot press 13.45 kg of metal matrix material at 170°C until the metal matrix material naturally cools to room temperature and then is removed.

[0127] As a preferred embodiment, after the metal base material and the graphene layer, and the metal cover plate and the graphene layer are bonded, laser welding can be used to weld the gap between the metal cover plate and the metal base material tightly, and then the whole is ground and polished.

[0128] Finally, fins are made on the opposite side of the metal base material relative to the stepped groove. The fin length is 27 mm, the thickness is 0.8 mm, the total number of fins is 26, and the thickness of the buffer part 7 between the inner core and the fin is 0.5 mm. At this point, a fin-type heat sink is prepared.

[0129] Example 5

[0130] The heat sink provided in this embodiment is made of the same material as that in Embodiment 1, except that the method of wrapping the inner core and the size of the inner core are different.

[0131] Specifically, in this embodiment, a single groove is provided on the surface of the metal base material along the thickness side wall; the size of the single groove matches the size of the graphene layer, which is 75mm*75mm*3mm in length*width*thickness.

[0132] The length and width of the metal cover plate are the same as those of the metal base material, and only the thickness is different. The size of the metal cover plate is: length*width*thickness 80mm*80mm*1mm, and the size of the metal base material is: length*width*thickness 80mm*80mm*4mm.

[0133] The single groove is used to clamp the graphene layer, and the length, width and thickness of the graphene layer match the size of the small groove. The size of the graphene layer is 75mm*75mm*3mm.

[0134] The graphene layer is clamped into the single groove along the longitudinal direction, the metal cover plate covers the notch of the single groove, and the graphene layer is wrapped between the metal layers to form an integral structure with an overall thickness of 5 mm.

[0135] As a preferred embodiment, paraffin wax can be coated between the metal substrate material and the graphene layer, and between the metal cover plate and the graphene layer. The coating amount of the paraffin wax is 0.036 g / cm 2 ; Cover the metal cover plate on the paraffin-coated graphene layer. After the assembly is completed, hot press 13.45 kg of metal matrix material at 170°C until the metal matrix material naturally cools to room temperature and then is removed.

[0136] As a preferred implementation, laser welding is used to tightly weld the gap between the upper metal cover plate and the lower metal cover plate, and then the entirety is ground and polished.

[0137] Finally, fins are made on the opposite side of the metal base material relative to the stepped groove. The fin length is 27 mm, the thickness is 0.8 mm, the total number of fins is 26, and the thickness of the buffer part 7 between the inner core and the fin is 1 mm. At this point, a fin-type heat sink is prepared.

[0138] Example 6

[0139] The heat sink provided in this embodiment has the same material and structure as those in Embodiment 5, except that the size of the inner core and the size of the metal cover plate are different.

[0140] Specifically, in this embodiment, a single groove is provided on the surface of the metal base material along the thickness side wall; the size of the single groove matches the size of the graphene layer, which is 75mm*75mm*4mm in length*width*thickness.

[0141] The metal cover plate has the same length and width as the metal base material, and only the thickness is different.

[0142] The dimensions of the metal cover are: length*width*thickness: 80mm*80mm*0.5mm.

[0143] The single groove is used to clamp the graphene layer, and the length, width and thickness of the graphene layer match the size of the small groove. The size of the graphene layer is 75*75*4mm.

[0144] The length and width of the metal cover plate are the same as those of the metal base material, and only the thickness is different. The size of the metal cover plate is: length*width*thickness 80mm*80mm*0.5mm, and the size of the metal base material is: length*width*thickness 80mm*80mm*4.5mm.

[0145] The graphene layer is clamped into the single groove along the longitudinal direction, the metal cover plate covers the notch of the single groove, and the graphene layer is wrapped between the metal layers to form an integral structure with an overall thickness of 5 mm.

[0146] As a preferred embodiment, paraffin wax can be coated between the metal substrate material and the graphene layer, and between the metal cover plate and the graphene layer. The coating amount of the paraffin wax is 0.035 g / cm 2 ; Cover the graphene layer coated with thermal conductive adhesive with a metal cover plate. After assembly, hot press with 13.45 kg of metal matrix material at 170°C until the metal matrix material cools naturally to room temperature and then is removed.

[0147] As a preferred implementation, laser welding is used to tightly weld the gap between the upper metal cover plate and the lower metal cover plate, and then the entirety is ground and polished.

[0148] Finally, fins are made on the opposite side of the metal base material relative to the stepped groove. The fin length is 27 mm, the thickness is 0.8 mm, the total number of fins is 26, and the thickness of the buffer part 7 between the inner core and the fin is 0.5 mm. At this point, a fin-type heat sink is prepared.

[0149] Example 7

[0150] The difference between this embodiment and embodiment 1 is only the material.

[0151] The material of the fin, the upper metal layer and the bottom metal layer selected in this embodiment is copper, and the rest is the same as that in Embodiment 1.

[0152] Example 8

[0153] The only difference between this embodiment and embodiment 1 is that solder is laid between the upper metal layer, the middle graphene layer and the bottom metal layer. The solder is AlSiMg, and the amount of solder laid can cover the middle graphene layer, with a covering thickness of 0.15 mm.

[0154] The other steps are the same.

[0155] Example 9

[0156] The difference between this embodiment and embodiment 1 is that the adhesive is silicone, the model of silicone is Wacker 745s, and the coating amount of silicone is 0.026 g / cm 2 .

[0157] Comparative Example 1

[0158] The common heat sink includes fins and a metal layer. The fin metal layer is made of aluminum metal, the length, width and thickness of the metal layer are 80*80*5mm, and the fin is 27mm long.

[0159] See Table 1 for a comparison of the structure and performance test results of the embodiments of the present invention and the comparative examples.

[0160] Table 1 Structure and performance test of embodiments and comparative examples

[0161]

[0162]

[0163] Performance Test:

[0164] 1. An ICEPAK thermal simulation analysis was performed on the aluminum / graphene composite heat sinks provided in Examples 1 to 6 and Comparative Example 1.

[0165] Taking Example 6 as an example, an aluminum composite graphene heat sink with a thickness of 0.5 mm and an inner core of 4 mm is retained in the upper shell, which is compared with the ordinary heat sink of Comparative Example 1.

[0166] Environmental conditions: fan radius 10mm, fixed air volume 0.001m 3 / s; heat source heat consumption 5W.

[0167] Under the above conditions, the overall temperature of the composite heat sink in Example 6 can be stabilized between 25-26°C.

[0168] Results Figure 3 and Figure 4 Compared with the heat sink without an inner core, the addition of the graphene thermal conductive sheet makes the heat at the bottom of the heat sink diffuse faster along the direction of the graphene layer, so that the heat at the bottom can quickly diffuse to both sides of the heat sink and be distributed to more fins, especially the fins at the edge can also be heated quickly, thereby accelerating the dissipation of heat and improving the heat dissipation efficiency of the radiator.

[0169] 2. Thermal simulation analysis was performed on the heat sinks of the embodiment and the comparative example under the same conditions.

[0170] Taking the aluminum / graphene composite heat sink of Example 1 and the copper / graphene composite heat sink of Example 7 as examples for analysis, a 20*20mm, 5W chip heat source, a radius of 10mm, and a 0.001m 3 / s fan, the results show that the temperature of both heat sinks can be maintained at 25-27 ° C. Among them, the copper heat sink, because copper itself has stronger thermal conductivity than aluminum, after being compounded with graphene, the heat at the bottom of the heat sink can naturally diffuse to the surrounding area, and the temperature is reduced more significantly, and the overall heat dissipation performance is better, and the overall temperature difference of the heat sink is also small.

[0171] 3. The same simulation was performed for different graphene core thicknesses.

[0172] Taking Example 5 and Example 6 as examples, the thickness of the inner core of the two is 3 mm and 4 mm respectively. The results show that the heat diffusion trend of the two composite heat sinks with inner cores of different thicknesses is consistent; however, the increase in the thickness of the inner core has a positive effect on the heat dissipation of the entire heat sink and the overall minimum temperature.

[0173] 4. Using instruments such as a DC stabilized power supply SS-605S and a paperless recorder SUP-R200T, an actual thermal conductivity comparison test was performed on the heat sinks of Example 1 and Comparative Example 1.

[0174] Experimental conditions: fan radius 10mm, fixed air volume 0.001m 3 / s, the heat source heat consumption is fixed at 5W, the air duct is constructed by resin plate to connect the fan and the radiator, and the temperature changes of the heat source at the bottom of the radiator and the center point of the upper fin end over a period of time are recorded by a paperless recorder.

[0175] First, a dual-point temperature change test was performed on the ordinary pure aluminum radiator in Example 1. The test results are shown in Figure 7 , the temperature of the heat source point is 36.96℃, the temperature of the center point of the fin is 29.23℃, and the test continues for 20 minutes. The temperatures of the heat source and the fin point tend to be stable, and the temperature difference is 7.73℃.

[0176] Then, a dual-point temperature change test was performed on the composite heat sink with a graphene core in Example 1. The results are shown in Figure 5 , the temperature of the heat source point is 35.85℃, the temperature of the center point of the fin is 29.63℃, and the test continues for 20 minutes. The temperatures of the heat source and the fin point tend to be stable, with a temperature difference of 6.22℃.

[0177] Finally, the bottom isotropic temperature of the composite heat sink with graphene core in Example 1 was tested. The test results are shown in Figure 6 As can be seen from the figure, there is a fixed temperature difference in the two directions at the bottom of the radiator, which shows that the graphene core has temperature guidance, and quickly and evenly transfers the center temperature of the heat source to the fins at both ends of the radiator; among them, the red line in the figure represents the temperature of the heat source; the green line represents the temperature in the direction of graphene arrangement; and the blue line represents the temperature in the direction of the fins.

[0178] From the above results we can see that:

[0179] (1) From Figure 5 and Figure 7 From the comparison, it can be seen that the heat dissipation time of an ordinary pure aluminum radiator is about 20 minutes, while the heat dissipation time of the radiator with a graphene core is about 15 minutes. In terms of heat dissipation speed, the heat dissipation speed of the radiator with a graphene core is more advantageous.

[0180] (2) From Figure 5 and Figure 7 It can be seen that the double-point temperature difference of the ordinary pure aluminum radiator is 7.73℃, while the double-point temperature difference of the radiator with a graphene core is 6.22℃. In terms of heat dissipation effect, the heat dissipation effect of the radiator with a graphene core is more advantageous.

[0181] (3) From Figure 6 It can be seen that due to the existence of the graphene core, the temperature in the arrangement direction of the flakes in the graphene core has always been slightly higher than the temperature in the fin direction, indicating that the graphene core has a guiding effect on heat, which can quickly disperse the temperature of the center point to each fin, thereby improving the overall heat dissipation effect and speed.

[0182] Obviously, by adopting the technical solution of the present invention and utilizing vertical graphene thermal conductive sheets, the speed of heat diffusion from the bottom of the heat sink to the fins is enhanced in the vertical direction. Also, due to the preparation of the thermal conductive sheets and the way they are installed on the heat sink, the speed of heat diffusion from the center of the heat sink to both ends of the fins is enhanced, so that more fins in the heat sink can effectively participate in the heat dissipation, thereby enhancing the diffusion of heat.

[0183] The above are only preferred embodiments of the present invention, which do not limit the protection scope of the present invention. For those skilled in the art, the present invention may have various modifications and changes. Within the spirit and principle of the present invention, changes, modifications, replacements, integrations and parameter changes to these embodiments by conventional substitutions or by being able to achieve the same functions without departing from the principles and spirit of the present invention all fall within the protection scope of the present invention.

Claims

1. A heat sink comprising: A metal base material, a metal cover plate, and a longitudinal heat conducting sheet embedded in the metal base material; The longitudinal heat conductive sheet serves as an inner core, and the metal base material and the metal cover plate form a metal shell to wrap the longitudinal heat conductive sheet inside, and the longitudinal heat conductive sheet is tightly fitted with the metal base material and the metal cover plate to form an integral structure.

2. The heat sink according to claim 1, characterized in that The material of the longitudinal heat conductive sheet is a graphene composite material; And / or, the metal matrix material is any one of silver, copper, aluminum, tungsten and diamond; And / or, the metal base material is the same as the metal cover plate material.

3. The heat sink according to claim 1 or 2, characterized in that: The material of the longitudinal heat conductive sheet is a composite of resin and graphene; And / or, the graphene composite material is formed by cyclically alternatingly stacking multiple resin layers and multiple graphene thermal conductive layers; the extension direction of the graphene in the graphene thermal conductive layer is consistent with the heat diffusion direction of the longitudinal thermal conductive sheet.

4. The heat sink according to claim 1 or 2, characterized in that: Also includes fins; The fins are perpendicular to the metal base material; The metal base material and the fin are an integral structure.

5. A method for manufacturing a heat sink according to any one of claims 1 to 4, characterized in that: The longitudinal heat conducting sheet is embedded in the metal base material by means of a clamping method and packaged with a metal cover plate. The metal cover plate, the longitudinal heat conducting sheet and the metal base material are combined together by hot pressing and welding to form an integral structure, thus obtaining the heat sink.

6. The method according to claim 5, characterized in that: The specific steps include: S1. Providing the metal matrix material; S2. A groove is formed at one end of the metal base material; S3. The longitudinal heat conductive sheet is embedded in the groove, and the size of the longitudinal heat conductive sheet matches the size of the groove; S4. The metal cover is bonded to the surface of the longitudinal heat conductive sheet and the metal base material; S5. The metal cover plate and the metal base material are formed into an integral structure by hot pressing and welding to obtain the heat sink; And / or, after S5, a fin is manufactured at the other end of the metal base material, wherein the fin is perpendicular to the metal base material.

7. The manufacturing method according to claim 6, characterized in that: The groove is a trapezoidal groove; the trapezoidal groove includes a first notch and a second notch; the size of the second notch is larger than the size of the first notch; The size of the longitudinal heat conducting sheet matches the size of the first notch; the size of the metal cover plate matches the size of the second notch; And / or, the thickness of the metal cover plate is 0.5 to 1.5 mm; The thickness of the graphene layer is 3 to 4 mm; Or, the groove is a single groove; the size of the longitudinal heat conductive sheet matches the size of the single groove; The size of the metal cover plate matches that of the metal base material; The thickness of the metal cover plate is 0.5 to 1 mm; The thickness of the longitudinal heat conductive sheet is 3 to 4 mm; The distance between the longitudinal heat conducting sheet and the fin is 0.5-1 mm.

8. The manufacturing method according to claim 6, characterized in that: The hot pressing conditions include: raising the temperature to 140-170°C, the pressure to 10-15kg, and then naturally cooling the temperature to room temperature; The welding is any one of brazing, vacuum diffusion welding and laser welding; the welding is to weld the gap between the metal cover plate and the metal base material so that the two are tightly and seamlessly combined; And / or, after the welding is completed, a grinding and polishing process is further included to make the surface of the heat sink smooth and flat.

9. The production method according to any one of claims 5 to 8, characterized in that: Solder is added between the metal cover plate and the longitudinal heat conductive sheet, and between the longitudinal heat conductive sheet and the metal base material, and the solder covers the longitudinal heat conductive sheet; And / or, the solder is at least one of AlSiMg, silver-based, and copper-based solders; The thickness of the solder coating is 0.1 to 0.15 mm; And / or, an adhesive layer is coated between the metal cover plate and the longitudinal heat conductive sheet, and between the longitudinal heat conductive sheet and the metal base material to fill the gap between the metal cover plate, the graphene layer and the metal base material; And / or, the coating amount of the adhesive layer is 0.025-0.04 g / cm 2 ; The bonding layer is thermally conductive glue or paraffin; Preferably, the thermally conductive adhesive is any one of silicone glue, epoxy resin glue and acrylate glue.

10. A heat sink with longitudinal heat conducting fins, comprising the heat sink according to any one of claims 1 to 4.

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