Graphene heat-conducting pad without powder falling

Abstract

The utility model provides a kind of non-dusting graphene heat-conducting pad, including graphene film, insulating polymer layer being covered in the surface of graphene film and the heat-conducting phase change material layer being arranged in the outside of insulating polymer layer;The graphene film is pleated structure.The non-dusting graphene heat-conducting pad of the utility model, reasonable in design, can solve the problem of graphene heat-conducting pad dusting in prior art at low cost, avoid the problem of chip short circuit caused by dusting, improve the stability and reliability of electronic equipment heat dissipation, have important practical significance and broad market prospect.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation materials technology, specifically to a graphene thermal pad that does not shed powder. Background Technology

[0002] Currently, electronic devices such as smartphones, laptops, and 5G communication equipment are constantly moving towards miniaturization, integration, multi-functionality, and high performance. These devices generate a significant amount of waste heat during operation, and the concentration and accumulation of this waste heat are becoming increasingly serious. For example, in the 5G era, electronic products are developing towards lightweight and highly integrated designs, significantly increasing the heat generation per unit area. High temperatures can cause electronic components to malfunction and reduce their lifespan, severely impacting the performance and stability of electronic devices. Therefore, efficiently dissipating waste heat from the interior of electronic devices is crucial to solving this problem.

[0003] When heat flows from the inside of electronic devices to the outside, it needs to cross multiple interfaces, and the interfacial contact thermal resistance severely limits heat transfer. To reduce contact thermal resistance, the industry commonly uses thermal interface materials, such as ceramic-filled thermal pads, carbon fiber-filled thermal pads, and graphite thermal pads. However, these traditional thermal interface materials have low intrinsic thermal conductivity, making it difficult to meet the requirements of high heat conduction.

[0004] Graphene is a novel material with a single-layer, two-dimensional honeycomb lattice structure composed of stacked carbon atoms. It possesses excellent thermal conductivity and has broad application prospects in heat conduction, heat dissipation, and thermal management. Graphene thermal pads, as a novel thermal interface material, are widely used in electronic device heat dissipation due to their outstanding thermal conductivity. By stacking and bonding layers of highly thermally conductive graphene films and cutting them into sheets along the stacking direction, graphene thermal pads can achieve high thermal conductivity in the vertical direction, meeting the heat dissipation requirements of high-power chips in 5G communication equipment.

[0005] Although graphene thermal pads have excellent thermal conductivity, they pose a significant risk of powder shedding during practical use. For example, a pleated graphene thermal pad reported in Chinese patent CN209052623U exhibits good thermal conductivity, but if powder shedding occurs, the detached powder may cause short circuits in the chip, thereby affecting the normal operation of electronic devices and reducing their stability and reliability.

[0006] To address the issue of powder shedding, Chinese patent CN211376628U proposes a method of edge-wrapping around the graphene thermal pad. This method reduces the risk of powder shedding from the edges of the graphene thermal pad to some extent, but it still cannot prevent powder shedding from the top and bottom surfaces of the thermal pad. Moreover, this method is complex, requiring additional edge-wrapping operations during production, increasing production costs and hindering large-scale production and application.

[0007] Therefore, there is an urgent need for a technical solution that can solve the problem of powder shedding from existing graphene thermal pads through a simple process and low cost, so as to improve the stability and reliability of heat dissipation in electronic devices and meet the requirements of reliability and stability in the field of electronic device heat dissipation. Utility Model Content

[0008] Purpose of the utility model: In order to overcome the above shortcomings, the purpose of this utility model is to provide a graphene thermal pad that does not shed powder, which aims to solve the problem of powder shedding in existing graphene thermal pads, avoid chip short circuits caused by powder shedding, and improve the stability and reliability of heat dissipation of electronic devices. It has important practical significance and broad market prospects.

[0009] Technical solution: A non-shedding graphene thermal pad, comprising a graphene film, an insulating polymer layer covering the surface of the graphene film, and a thermally conductive phase change material layer disposed outside the insulating polymer layer; wherein the graphene film has a wrinkled structure.

[0010] The graphene thermal pad described in this invention encapsulates an insulating polymer layer on the surface of a graphene film, forming a continuous and uniform protective film. This effectively prevents graphene particles from detaching from the thermal pad, completely eliminating the risk of powder shedding. The graphene film itself possesses excellent thermal conductivity, and the ultra-thin insulating polymer layer does not significantly affect its thermal conductivity. Simultaneously, the outer thermally conductive phase change material layer further reduces interfacial thermal resistance and improves heat transfer efficiency, allowing heat generated by electronic devices to dissipate more quickly. The insulating polymer layer not only prevents powder shedding but also provides a degree of electrical isolation, further ensuring the safe operation of electronic devices and reducing the risk of equipment damage due to electrical faults.

[0011] Furthermore, in the aforementioned non-shedding graphene thermal pad, the insulating polymer layer is tightly bonded to the surface of the graphene film; the thermally conductive phase change material layer is disposed on the upper and lower sides of the graphene film and is tightly bonded to the graphene film covered with the insulating polymer layer.

[0012] The tightly fitted structure makes the entire thermal pad more stable, better protects the graphene film, and facilitates heat transfer between layers, reducing thermal resistance and thus further improving the thermal conductivity of the thermal pad.

[0013] Furthermore, in the aforementioned non-shedding graphene thermal pad, the pleated structure is periodically serrated.

[0014] The graphene film of this invention features a periodic, serrated pleated structure, and the insulating polymer layer has a uniform thickness throughout, avoiding issues such as uneven stress, pleated structure collapse, or even coating damage at bends caused by uneven coating thickness, which can lead to powder shedding. Furthermore, the serrated pleated structure increases the surface area of ​​the graphene film, thereby improving the contact area with the insulating polymer layer and the thermally conductive phase change material layer, facilitating heat transfer and exchange, and further enhancing thermal conductivity. The periodic, serrated pleated structure also gives the thermal pad better flexibility, allowing it to better adapt to different installation environments and shape requirements, thus improving the product's applicability.

[0015] Furthermore, in the aforementioned non-shedding graphene thermal pad, the graphene film is a graphene film modified with a surface silane coupling agent.

[0016] Modification with silane coupling agents can improve the surface properties of graphene films, thereby enhancing the bonding force between the insulating polymer material layer and the graphene film. The enhanced bonding force and improved surface properties help improve the durability of thermal pads, enabling them to maintain good performance during long-term use.

[0017] Furthermore, in the aforementioned non-shedding graphene thermal pad, the thickness of the graphene film is 12-32 micrometers.

[0018] This thickness range ensures that the graphene film has good thermal conductivity while maintaining its structural stability and flexibility, and meets the application requirements of different electronic devices.

[0019] Furthermore, in the aforementioned non-shedding graphene thermal pad, the thickness of the insulating polymer layer is 0.5~2 micrometers.

[0020] The insulating polymer layer within this thickness range can effectively prevent graphene particles from falling off, achieving the function of preventing powder shedding, while not significantly affecting the thermal conductivity of the graphene thermal pad, ensuring that heat can be transferred smoothly.

[0021] Furthermore, in the aforementioned non-shedding graphene thermal pad, the thickness of the thermally conductive phase change material layer is 25~100 micrometers.

[0022] Thermally conductive phase change materials can be organic phase change materials (paraffin, fatty alcohols, etc.), inorganic phase change materials (such as low-melting-point metals gallium, indium and their alloys, etc.), composite phase change materials (such as organic-inorganic composite phase change materials, microencapsulated reinforced thermally conductive phase change materials, etc.).

[0023] With a thickness range of 25 to 100 micrometers, it can effectively reduce interfacial thermal resistance. Its thickness can be adjusted according to specific heat dissipation requirements to meet diverse application scenarios.

[0024] Furthermore, in the aforementioned non-shedding graphene thermal pad, the insulating polymer layer is made of parylene.

[0025] Parylene possesses excellent insulating properties and good chemical stability, while also exhibiting superior film-forming properties. It can form continuous and uniform films on the surface of graphene films, tightly adhering to the surface of wrinkled structures to achieve a good anti-powdering effect. Moreover, its film-forming process is relatively simple, which is conducive to large-scale production.

[0026] The beneficial effects of this invention are as follows: The non-shedding graphene thermal pad of this invention is rationally designed. By coating a thin layer of insulating polymer material onto the surface of a graphene film with a wrinkled structure, this protective film adheres tightly to the graphene film surface, forming a continuous and uniform protection. This completely prevents graphene particles from falling off the graphene film, fundamentally eliminating the phenomenon of powder shedding. This effectively avoids the risk of chip short circuits caused by powder shedding and ensures the stable operation of electronic devices. The thickness of the insulating polymer layer is only 0.5~2 mm. Due to its ultra-thin nature, the micrometer thickness does not significantly affect the thermal conductivity of graphene thermal pads. Graphene itself possesses excellent thermal conductivity, ensuring that while preventing powder shedding, it can fully leverage its thermal conductivity advantages to meet the heat dissipation requirements of electronic devices. The thermally conductive phase change material layer further reduces the interfacial thermal resistance of the graphene thermal pad, improving heat transfer efficiency and allowing the heat generated by electronic devices to dissipate more quickly. Compared to the complex process of wrapping the graphene thermal pad with an insulating polymer layer in existing technologies, the process of depositing an insulating polymer layer is more direct and simpler, requiring no complex equipment or cumbersome operating procedures, making it easy to implement in production. Due to the simplicity of the process, it reduces manpower, material resources, and time costs in the production process. At the same time, the cost of the insulating polymer material itself is relatively low, which is conducive to large-scale promotion and application. Attached Figure Description

[0027] Figure 1 This is a partial cross-sectional view of the non-shedding graphene thermal pad described in this utility model.

[0028] In the picture:

[0029] Graphene film 1; insulating polymer layer 2; thermally conductive phase change material layer 3. Detailed Implementation

[0030] The following is in conjunction with the appendix Figure 1 The present invention will be further illustrated by the embodiments.

[0031] Example 1

[0032] This embodiment 1 provides a non-shedding graphene thermal pad, including a pleated graphene film 1 and an insulating polymer layer 2 covering the surface of the graphene film 1.

[0033] like Figure 1 As shown, the folded structure has a periodic serrated shape.

[0034] The graphene film 1 has a thickness of 32 micrometers. The insulating polymer layer 2 is made of parylene and has a thickness of 0.5 micrometers.

[0035] The method for fabricating the non-shedding graphene thermal pad in Example 1 is as follows:

[0036] (1) Surface modification: The commercial graphene thermal conductive film was immersed in concentrated nitric acid for 2 hours. This step can activate the surface of the graphene film and increase its reactivity. After cleaning and drying, it was immersed in silane coupling agent at 80°C for 6 hours. The silane coupling agent can form chemical bonds on the surface of the graphene thermal conductive film, providing a basis for the strong bonding of the subsequent insulating polymer layer 2. After cleaning and drying, it was ready for use.

[0037] (2) Fabrication of a wrinkled graphene film 1: The graphene thermally conductive film from step (1) is bonded to the stretched elastomer. After the elastomer releases its tension and retracts, the thermally conductive film retracts along with the elastomer, separating the graphene thermally conductive film from the elastomer to obtain a wrinkled graphene film 1. This wrinkled structure can increase the flexibility and surface area of ​​the graphene film 1, improve its contact area with other materials, and thus enhance its thermal conductivity.

[0038] (3) Pressing and cutting: The graphene film 1 with the above-mentioned pleated structure is pressed into a sheet of the target size and then laser-cut. Laser cutting can ensure the cutting accuracy and make the size of the graphene thermal pad meet the design requirements.

[0039] (4) Depositing insulating polymer layer 2: The graphene film 1 with wrinkled structure from step (3) is placed in the vacuum chamber of a chemical vapor deposition (CVD) apparatus. The process parameters such as temperature and vacuum are controlled to deposit an insulating polymer layer 2 (poly(p-xylene)) on its surface. CVD can make the insulating polymer material uniformly adhere to the surface of the graphene film 1, forming a continuous and uniform protective film.

[0040] Example 2

[0041] This embodiment 2 provides a non-shedding graphene thermal pad, including a pleated graphene film 1 and an insulating polymer layer 2 covering the surface of the graphene film 1.

[0042] like Figure 1 As shown, the folded structure has a periodic serrated shape.

[0043] The graphene film 1 has a thickness of 32 micrometers. The insulating polymer layer 2 is made of parylene and has a thickness of 2 micrometers.

[0044] The method for manufacturing the non-shedding graphene thermal pad in Example 2 is the same as that in Example 1.

[0045] Example 3

[0046] This embodiment 3 provides a non-shedding graphene thermal pad, including a pleated graphene film 1 and an insulating polymer layer 2 covering the surface of the graphene film 1.

[0047] like Figure 1 As shown, the folded structure has a periodic serrated shape.

[0048] The graphene film 1 has a thickness of 12 micrometers. The insulating polymer layer 2 is made of parylene and has a thickness of 0.5 micrometers.

[0049] The method for manufacturing the non-shedding graphene thermal pad in Example 3 is the same as that in Example 1.

[0050] Example 4

[0051] This embodiment 4 provides a non-shedding graphene thermal pad, including a pleated graphene film 1, an insulating polymer layer 2 covering the surface of the graphene film 1, and a thermally conductive phase change material layer 3 placed outside the insulating polymer layer 2.

[0052] like Figure 1 As shown, the folded structure has a periodic serrated shape.

[0053] The graphene film 1 has a thickness of 32 micrometers. The insulating polymer layer 2 is made of parylene and has a thickness of 0.5 micrometers. The thermally conductive phase change material layer 3 has a thickness of 25 micrometers.

[0054] The method for fabricating the non-shedding graphene thermal pad in Example 4 is as follows:

[0055] (1) Surface modification: The commercial graphene thermal conductive film was immersed in concentrated nitric acid for 2 hours, then removed, cleaned and dried, and then immersed in silane coupling agent at 80°C for 6 hours. After that, it was removed, cleaned and dried for use.

[0056] (2) Fabrication of a pleated graphene film 1: The graphene thermal conductive film in step (1) is bonded to the stretched elastomer. After the elastomer releases the tension and retracts, the thermal conductive film retracts along with the retraction of the elastomer. The graphene thermal conductive film is then separated from the elastomer to obtain a pleated graphene film 1.

[0057] (3) Pressing and cutting: Press the graphene film 1 with the above-mentioned pleated structure into a sheet of the target size, and then perform laser cutting.

[0058] (4) Deposit insulating polymer layer 2: Place the graphene film 1 with wrinkled structure in step (3) in the vacuum chamber of chemical vapor deposition equipment, control the process parameters such as temperature and vacuum degree, and deposit insulating polymer layer 2 (poly(p-xylene)) on its surface.

[0059] (5) Coating with thermally conductive phase change material: In order to further reduce the interfacial thermal resistance of the graphene thermal pad, a layer of thermally conductive phase change material is coated on its upper and lower surfaces to form thermally conductive phase change material 3.

[0060] This invention provides several embodiments. By adjusting parameters such as the thickness of the insulating polymer layer 2, the thickness of the graphene film 1, and whether or not a thermally conductive phase change material is added, the diverse needs of different electronic devices for heat dissipation performance and anti-dust removal can be met. For example, for some electronic devices with high heat dissipation requirements but limited space, a thinner graphene film 1 and a thinner insulating polymer layer 2 can be selected; while for some devices with extremely high stability requirements, a thermally conductive phase change material can be added to further improve the heat dissipation effect. This flexible implementation method makes the product have a wider range of application prospects.

[0061] Comparative Example 1

[0062] Comparative Example 1 provides a graphene thermal pad whose structure is based on Chinese Patent No. CN211376628U, which provides a graphene film with a 32-micron graphene film and the same size as that in Example 1, featuring an edge-wrapped, pleated graphene thermal pad.

[0063] The graphene thermal pads of Examples 1-4 and Comparative Example 1 were repeatedly transferred to the target chip 10 times. Then, a heat sink was installed and secured on the graphene thermal pad and the chip. The heat sink was then removed, and the presence of powder falling around the chip was observed. The test results are shown in Table 1.

[0064] Table 1

[0065] Is there any powder loss? Example 1 none Example 2 none Example 3 none Example 4 none Comparative Example 1 Yes, quite a lot

[0066] As shown in Table 1, compared with Comparative Example 1, the graphene thermal pad prepared using the technical solution of this utility model does not shed powder during repeated transfer operations and installation, which can effectively avoid the risk of chip short circuit.

[0067] In summary, this invention has significant advantages in solving the problem of powder shedding in graphene thermal pads, as well as in terms of process cost, thermal conductivity, and product reliability. It can efficiently and cost-effectively produce graphene thermal pads with anti-powder shedding function, meeting the reliability and stability requirements of electronic device heat dissipation.

[0068] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present utility model, and these improvements should also be considered within the protection scope of the present utility model.

Claims

1. A graphene thermal conductive pad that does not shed powder, characterized in that, It includes a graphene film (1), an insulating polymer layer (2) covering the surface of the graphene film (1), and a thermally conductive phase change material layer (3) disposed on the outside of the insulating polymer layer (2); wherein the graphene film (1) has a wrinkled structure.

2. The non-shedding graphene thermal pad according to claim 1, characterized in that, The insulating polymer layer (2) is tightly bonded to the surface of the graphene film (1); the thermally conductive phase change material layer (3) is disposed on the upper and lower sides of the graphene film (1) and is tightly bonded to the graphene film (1) covered with the insulating polymer layer (2).

3. The non-shedding graphene thermal pad according to claim 1, characterized in that, The folded structure has a periodic serrated shape.

4. The non-shedding graphene thermal pad according to claim 1, characterized in that, The graphene film (1) is a graphene film modified with a surface silane coupling agent.

5. The non-shedding graphene thermal pad according to claim 1, characterized in that, The thickness of the graphene film (1) is 12~32 micrometers.

6. The non-shedding graphene thermal pad according to claim 1, characterized in that, The thickness of the insulating polymer layer (2) is 0.5~2 micrometers.

7. The non-shedding graphene thermal pad according to claim 1, characterized in that, The thickness of the thermally conductive phase change material layer (3) is 25~100 micrometers.

8. The non-shedding graphene thermal pad according to claim 1, characterized in that, The insulating polymer layer (2) is made of parylene.

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