A high-thermal-conductivity foam with a multi-pore gradient structure

Abstract

The utility model discloses a kind of high-thermal-conductivity bubble cotton of porous interstice gradient structure, including bubble cotton main body and equidistantly open several heat-conducting through holes on bubble cotton main body, the aperture of heat-conducting through hole is gradient design, and aperture gradually increases from bottom to top, bubble cotton main body is mainly composed of base layer. The utility model heat-conducting through hole gradient design optimizes heat-conducting path, improves heat conduction efficiency;Flow buffer layer uses silica gel foam, can absorb installation tolerance, reduce contact thermal resistance;Base layer selects polyurethane bubble cotton, has basic performance and controllable cost simultaneously;Thermal conductivity enhancement layer uses graphite sheet to improve horizontal thermal conductivity;Thermal conductivity core layer is filled with silica gel to realize vertical efficient heat conduction and adapt to deformation with aluminium nitride ceramic;Surface protective layer uses polyimide film to insulate environment, provide insulation;Electromagnetic shielding layer uses nickel-plated copper foil to shield interference, can be grounded;Bottom support layer uses glass fiber reinforced polyester sheet to enhance rigidity, provide insulation flame-retardant performance, and comprehensive performance is excellent.

Description

Technical Field

[0001] This utility model relates to the field of foam technology, and in particular to a high thermal conductivity foam with a porous gradient structure. Background Technology

[0002] In the field of electronic devices, foam, as an important functional material, is widely used in heat dissipation, cushioning, sealing, and other aspects. With the continuous improvement of electronic device performance, the heat generated by its internal components is increasing dramatically, placing higher demands on the thermal conductivity of foam. At the same time, electronic devices are subject to various external forces and electromagnetic interference during installation and use; therefore, foam also needs to possess good cushioning and electromagnetic shielding properties.

[0003] In the prior art, such as the foam disclosed in Chinese Patent Publication No. CN206030691U, there is a foam comprising an adhesive layer, a foam layer, and a release paper layer, wherein the width of the release paper layer is greater than the width of the foam layer. This invention primarily increases the width of the release paper layer in the foam, making the overall size of the foam larger than the fixture opening, facilitating the adsorption of the assembly fixture, thereby improving the accuracy of assembly and attachment, increasing the assembly efficiency of electronic products, and reducing material waste and subsequent foam tearing issues. However, this type of foam has significant shortcomings in terms of thermal conductivity, cushioning performance, and electromagnetic shielding, making it difficult to meet the current demands of electronic devices for high-performance foam. Specifically, its thermal conductivity structure is simple, failing to effectively optimize the heat conduction path, resulting in low heat transfer efficiency; in terms of cushioning, it lacks an effective absorption mechanism for device mounting tolerances, making it difficult to ensure close contact between the thermal conductive layer and the heat dissipation component, resulting in high contact thermal resistance; and it lacks electromagnetic shielding functionality, failing to prevent interference from high-frequency signals on thermal conductivity. Therefore, developing a porous gradient structure foam with comprehensive properties such as high thermal conductivity, good buffering performance, and electromagnetic shielding is of great practical significance. Utility Model Content

[0004] The purpose of this invention is to provide a high thermal conductivity foam with a porous gradient structure. The gradient design of the thermally conductive through-holes optimizes the heat conduction path and improves the heat transfer efficiency. The flow-guiding buffer layer uses silicone foam, which can absorb installation tolerances and reduce contact thermal resistance. The base layer is made of polyurethane foam, which has both basic performance and controllable cost. The thermally conductive reinforcement layer uses graphite sheets to improve lateral thermal conductivity. The thermally conductive core layer uses aluminum nitride ceramic filled with silicone to achieve efficient vertical thermal conduction and adapt to deformation. The surface protective layer uses polyimide film to isolate the environment and provide insulation. The electromagnetic shielding layer uses nickel-plated copper foil to shield interference and can be grounded. The bottom support layer uses glass fiber reinforced polyester sheet to enhance rigidity and provide insulation and flame retardant properties. It has excellent comprehensive performance and broad application prospects.

[0005] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0006] A high thermal conductivity foam with a porous gradient structure, comprising:

[0007] The foam body has a number of heat-conducting through holes that are equidistantly opened on the foam body. The diameter of the heat-conducting through holes is designed with a gradient, and the diameter gradually increases from bottom to top. The foam body is mainly composed of a base layer. A heat-conducting enhancement layer, a heat-conducting core layer and a surface protective layer are arranged in sequence on one side of the base layer. A flow-guiding buffer layer, an electromagnetic shielding layer and a bottom support layer are arranged in sequence on the other side of the base layer.

[0008] The aforementioned porous gradient structure of high thermal conductivity foam includes a base layer of polyurethane foam. The polyurethane foam serves as the main support structure, providing basic properties such as elastic cushioning and sealing against dust. It also acts as a carrier for the thermally conductive functional layer. Due to its lightweight, good compression resilience, and controllable cost, polyurethane foam is suitable for large-scale applications.

[0009] The high thermal conductivity foam with a porous gradient structure mentioned above, wherein the thermally conductive reinforcing layer is a graphite sheet, which utilizes the high planar thermal conductivity of graphite for rapid lateral heat transfer. The graphite sheet is thin, can be bent to fit complex surfaces, and has a thermal conductivity far higher than that of metal powder filler materials.

[0010] The aforementioned porous gradient structure of high thermal conductivity foam includes a thermally conductive core layer made of aluminum nitride ceramic-filled silicone. The high thermal conductivity of aluminum nitride enables efficient thermal conduction in the vertical direction, while the silicone matrix provides flexibility to accommodate device deformation.

[0011] In the above-mentioned high thermal conductivity foam with a porous gradient structure, the surface protective layer is a polyimide film. By setting the polyimide film, the external environment can be isolated, the thermally conductive layer can be protected, and insulation performance can be provided at the same time.

[0012] In the above-mentioned porous gradient structure of high thermal conductivity foam, the flow-guiding buffer layer is a silicone foam. The silicone foam absorbs the tolerance gaps during device installation, ensuring that the thermal conductive layer is in close contact with the heat dissipation component and reducing contact thermal resistance.

[0013] In the above-mentioned high thermal conductivity foam with a porous gradient structure, the electromagnetic shielding layer is a nickel-plated copper foil. The nickel-plated copper foil shields electromagnetic interference, prevents high-frequency signals from interfering with the thermal conductivity, and also provides a grounding function.

[0014] The aforementioned porous gradient structure of high thermal conductivity foam includes a bottom support layer made of glass fiber reinforced polyester sheet. The glass fiber reinforced polyester sheet enhances the overall rigidity of the foam, preventing excessive deformation during installation, while also providing insulation and flame retardant properties.

[0015] This utility model has at least the following beneficial effects:

[0016] 1. This utility model realizes a high thermal conductivity foam with a porous gradient structure. The gradient design of the thermally conductive through holes optimizes the heat conduction path and improves the heat transfer efficiency. The flow-guiding buffer layer uses silicone foam, which can absorb installation tolerances and reduce contact thermal resistance. The base layer is made of polyurethane foam, which has both basic performance and controllable cost. The thermally conductive reinforcement layer uses graphite sheets to improve lateral thermal conductivity. The thermally conductive core layer uses aluminum nitride ceramic filled with silicone to achieve vertical high-efficiency thermal conduction and adapt to deformation. The surface protective layer uses polyimide film to isolate the environment and provide insulation. The electromagnetic shielding layer uses nickel-plated copper foil to shield interference and can be grounded. The bottom support layer uses glass fiber reinforced polyester sheet to enhance rigidity and provide insulation and flame retardant properties. It has excellent comprehensive performance and broad application prospects.

[0017] 2. Optimized heat conduction path: By setting heat conduction through holes with a gradient design where the hole diameter gradually increases from bottom to top, this unique design allows heat to be transferred along the optimal path within the foam, effectively improving heat conduction efficiency and enhancing the thermal conductivity of the foam, thus better meeting the high-efficiency heat dissipation requirements of electronic devices.

[0018] 3. Enhanced Energy Absorption and Buffering with Ensured Tight Contact: The thermally conductive buffer layer utilizes silicone foam. During device assembly, the silicone foam absorbs tolerance gaps, effectively buffering external impacts and protecting internal components. Simultaneously, it ensures tight contact between the thermally conductive layer and the heat dissipation components, significantly reducing contact thermal resistance and further enhancing thermal conductivity, thereby improving the stability and reliability of electronic device heat dissipation.

[0019] 4. Excellent overall performance:

[0020] Base layer: Polyurethane foam is selected as the main support structure, which not only provides basic properties such as elastic cushioning and sealing against dust, but also serves as a carrier for the thermally conductive functional layer. Polyurethane foam is lightweight, has good compression resilience, and is cost-controllable, making it very suitable for large-scale applications, reducing production costs while ensuring foam performance.

[0021] Thermally enhanced layer: Graphite sheets are used, leveraging graphite's high planar thermal conductivity to achieve rapid lateral heat transfer. The thin graphite sheets can be bent to fit complex surfaces, adapting to electronic components of different shapes, and their thermal conductivity is far superior to that of metal powder fillers, effectively improving the lateral thermal conductivity of the foam.

[0022] Thermally conductive core layer: Composed of aluminum nitride ceramic filled with silicone. The high thermal conductivity of aluminum nitride enables efficient vertical heat conduction, while the silicone matrix provides flexibility, allowing the foam to adapt to device deformation and ensuring good thermal conductivity under different operating conditions.

[0023] Surface protective layer: Made of polyimide film, it can isolate the external environment, prevent moisture, dust and other impurities from entering the foam, protect the heat-conducting layer from damage, and provide insulation properties to ensure the safe operation of electronic equipment.

[0024] Electromagnetic shielding layer: Nickel-plated copper foil is used to effectively shield electromagnetic interference, prevent high-frequency signals from interfering with thermal conductivity, ensure stable operation of the foam in complex electromagnetic environments, and provide grounding function, further enhancing the electromagnetic compatibility of electronic equipment.

[0025] Bottom support layer: Utilizing glass fiber reinforced polyester sheet, this enhances the overall rigidity of the foam, preventing excessive deformation during installation and ensuring structural stability. Simultaneously, this material provides insulation and flame retardant properties, improving the safety and reliability of electronic equipment. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0027] Figure 1 This is a schematic diagram of the high thermal conductivity foam with a porous gradient structure according to this utility model;

[0028] Figure 2 This utility model Figure 1 A magnified schematic diagram of the local structure at point A;

[0029] Figure 3 This is a cross-sectional schematic diagram of the high thermal conductivity foam with a porous gradient structure according to this utility model.

[0030] Explanation of icon numbers:

[0031] 1. Foam body; 2. Thermal conductive holes;

[0032] 101. Grassroots level;

[0033] 102. Thermally conductive enhancement layer; 1021. Thermally conductive core layer; 1022. Surface protective layer;

[0034] 103. Flow-guiding buffer layer; 1031. Electromagnetic shielding layer; 1032. Bottom support layer. Detailed Implementation

[0035] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0036] Please refer to Figures 1 to 3As shown, an embodiment of this utility model provides a high thermal conductivity foam with a porous gradient structure, comprising: a foam body 1 and a plurality of thermally conductive through holes 2 equidistantly opened on the foam body 1. The diameter of the thermally conductive through holes 2 is gradient-designed, and the diameter gradually increases from bottom to top. The foam body 1 is mainly composed of a base layer 101. A thermally conductive reinforcing layer 102, a thermally conductive core layer 1021 and a surface protective layer 1022 are sequentially arranged on one side of the base layer 101. A flow-guiding buffer layer 103, an electromagnetic shielding layer 1031 and a bottom support layer 1032 are sequentially arranged on the other side of the base layer 101.

[0037] By adopting the above technical solution, the high thermal conductivity foam achieves performance improvements in thermal conductivity, buffering, electromagnetic shielding, and other aspects through its unique structural design and reasonable layout of each functional layer, thus better meeting the needs of electronic devices for high-performance foam.

[0038] To provide a stable and well-performing main support structure, in this embodiment, the base layer 101 is made of polyurethane foam. Polyurethane foam not only possesses basic properties such as elastic cushioning and dustproofing, effectively protecting internal electronic components from external impacts and dust intrusion; it also serves as a carrier for the thermally conductive functional layer, providing a stable foundation for the installation of other functional layers. Due to its lightweight and good compression resilience, polyurethane foam does not add excessive weight while ensuring the overall performance of the foam, and it can adapt to a certain degree of deformation; furthermore, its cost is controllable, making it very suitable for large-scale applications and helping to reduce product production costs.

[0039] To enhance the lateral thermal conductivity of the foam, in this embodiment, the thermally conductive reinforcement layer 102 is made of graphite sheets. Graphite has extremely high planar thermal conductivity. Utilizing this characteristic, graphite sheets can quickly achieve lateral heat transfer, rapidly diffusing heat in the horizontal direction and improving the overall thermal uniformity of the foam. Moreover, graphite sheets are thin and can be bent to fit complex surfaces, adapting well to electronic components of different shapes and structures, ensuring full contact with the component surface, and improving thermal conductivity efficiency. Compared to metal powder filler materials, graphite sheets have higher thermal conductivity and can more effectively improve the thermal conductivity of the foam.

[0040] To achieve efficient vertical heat conduction in the foam, in this embodiment, the thermally conductive core layer 1021 is made of aluminum nitride ceramic filled with silicone. Aluminum nitride ceramic has excellent thermal conductivity, enabling rapid heat transfer in the vertical direction, forming an efficient heat conduction channel. The silicone substrate, on the other hand, has good flexibility, adapting to deformations during device operation. This ensures that the thermally conductive core layer 1021 maintains close contact with the upper and lower layers, preventing a decrease in thermal conductivity due to device deformation, thus ensuring efficient and stable vertical heat conduction.

[0041] To protect the internal thermally conductive layer and provide insulation, in this embodiment, the surface protective layer 1022 is made of polyimide film. Polyimide film has good chemical stability and insulation properties, effectively isolating moisture, dust, chemicals, etc., from the external environment, preventing these factors from damaging the internal thermally conductive layer and extending the service life of the foam. Simultaneously, polyimide film also possesses excellent insulation properties, preventing safety issues such as leakage between the foam and electronic components, ensuring the normal operation of electronic equipment.

[0042] To ensure tight contact between the thermally conductive layer and the heat dissipation components and to absorb installation tolerances, in this embodiment, the flow-guiding buffer layer 103 is made of silicone foam. During device assembly, tolerance gaps are unavoidable due to factors such as processing precision. Silicone foam has good elasticity and energy absorption properties, which can absorb these tolerance gaps, allowing the thermally conductive layer to fit tightly against the heat dissipation components, greatly reducing contact thermal resistance and improving heat transfer efficiency. At the same time, the silicone foam also acts as a buffer, reducing the impact of external impacts on internal components and protecting the safety of electronic components.

[0043] To shield against electromagnetic interference and prevent its impact on thermal conductivity, in this embodiment, the electromagnetic shielding layer 1031 is made of nickel-plated copper foil. Electromagnetic interference is a common problem in modern electronic devices; high-frequency signals can interfere with the thermal conductivity of foam, affecting the normal operation of electronic equipment. Nickel-plated copper foil has excellent electromagnetic shielding performance, effectively shielding against external electromagnetic interference, preventing high-frequency signals from interfering with thermal conductivity, and ensuring stable thermal conductivity of the foam in complex electromagnetic environments. Simultaneously, the nickel-plated copper foil also provides grounding functionality, further enhancing the electromagnetic compatibility of electronic equipment.

[0044] To enhance the overall rigidity of the foam and prevent excessive deformation during installation, in this embodiment, the bottom support layer 1032 is made of glass fiber reinforced polyester sheet. Glass fiber reinforced polyester sheet has high strength and rigidity, which enhances the overall structural strength of the foam, preventing excessive deformation due to external forces during installation and ensuring the shape stability and dimensional accuracy of the foam. Simultaneously, this material also has good insulation and flame-retardant properties, preventing safety issues such as leakage between the foam and electronic components. Furthermore, in emergencies such as fires, it effectively prevents the spread of fire, improving the safety of electronic equipment.

[0045] The working principle of this invention is as follows: When an electronic component generates heat, the heat is first transferred to the thermally conductive enhancement layer 102 through the surface protective layer 1022 in contact with the component. The graphite sheets in the thermally conductive enhancement layer 102 utilize their high planar thermal conductivity to rapidly diffuse the heat in the horizontal direction, making the heat distribution more uniform. Subsequently, the heat is transferred to the thermally conductive core layer 1021. The aluminum nitride ceramic in the silicone-filled aluminum nitride layer exhibits high thermal conductivity, efficiently transferring the heat in the vertical direction. The gradient design of the thermally conductive vias 2 further optimizes the heat transfer path, enabling the heat to be quickly discharged in the optimal direction. During the heat transfer process, the flow-guiding buffer layer 103 absorbs the tolerance gaps during device installation, ensuring close contact between the thermally conductive layer and the heat dissipation component, reducing contact thermal resistance, and ensuring that the heat can be smoothly transferred to the heat dissipation component. The electromagnetic shielding layer 1031 shields against external electromagnetic interference, preventing the influence of high-frequency signals on the thermal conductivity and ensuring the stability of the thermal conduction process. The bottom support layer 1032 enhances the overall rigidity of the foam, prevents excessive deformation during installation, and ensures the structural stability and dimensional accuracy of the foam, thereby providing stable and reliable heat dissipation and protection for electronic components.

[0046] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A high thermal conductivity foam with a porous gradient structure, comprising a foam body (1) and a plurality of thermally conductive through holes (2) equidistantly disposed on the foam body (1), characterized in that, The diameter of the heat-conducting through hole (2) is designed with a gradient, and the diameter gradually increases from bottom to top. The foam body (1) is mainly composed of a base layer (101). A heat-conducting enhancement layer (102), a heat-conducting core layer (1021) and a surface protective layer (1022) are arranged in sequence on one side of the base layer (101). A flow-guiding buffer layer (103), an electromagnetic shielding layer (1031) and a bottom support layer (1032) are arranged in sequence on the other side of the base layer (101).

2. The high thermal conductivity foam with a porous gradient structure according to claim 1, characterized in that: The base layer (101) is polyurethane foam.

3. The high thermal conductivity foam with a porous gradient structure according to claim 2, characterized in that: The thermally conductive enhancement layer (102) is a graphite sheet.

4. The high thermal conductivity foam with a porous gradient structure according to claim 3, characterized in that: The thermally conductive core layer (1021) is aluminum nitride ceramic filled with silicone.

5. The high thermal conductivity foam with a porous gradient structure according to claim 4, characterized in that: The surface protective layer (1022) is a polyimide film.

6. The high thermal conductivity foam with a porous gradient structure according to claim 5, characterized in that: The flow-guiding buffer layer (103) is a silicone foam.

7. The high thermal conductivity foam with a porous gradient structure according to claim 6, characterized in that: The electromagnetic shielding layer (1031) is nickel-plated copper foil.

8. A high thermal conductivity foam with a porous gradient structure according to any one of claims 1-7, characterized in that: The bottom support layer (1032) is a glass fiber reinforced polyester sheet.

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