A novel heat-conducting cable

Abstract

This utility model provides a novel heat-conducting cable, which includes a heating device connection end, a flexible heat-conducting section composed of multiple layers of flexible high thermal conductivity graphite film and high thermal conductivity metal composite film stacked together, and a heat sink connection end. By improving the structural design, the problem of anisotropy constraint and deformation coordination of graphite film in the prior art is solved, thereby improving the heat conduction efficiency, structural reliability and service life of the heat-conducting cable, and has important application value.

Description

Technical Field

[0001] This utility model relates to the field of thermal management technology, specifically to a flexible heat-conducting cable for efficient heat transfer between a mobile heat source and a heat sink, which is particularly suitable for heat conduction systems under dynamic operating conditions such as aerospace and new energy batteries. Background Technology

[0002] Heat-conducting cables are used to achieve efficient heat transfer between a mobile heat source and a heat sink. Their core requirements are high thermal conductivity, flexibility, and tensile strength. A typical structure consists of a flexible heat-conducting section and heat-generating device connection ends and heat sink connection ends at both ends.

[0003] Current technology has the following problems:

[0004] 1. Anisotropy constraint: The horizontal thermal conductivity (>1500W / mK) of high thermal conductivity graphite film differs by orders of magnitude from that in the vertical direction (<10W / mK), resulting in a significant thermal barrier in the thickness direction of the hot-end stacked structure, which reduces the overall heat transfer efficiency by more than 40%.

[0005] 2. Deformation Coordination Challenge: Under bending conditions, multilayer graphite films are difficult to deform synchronously, which can easily lead to interlayer misalignment and stress concentration. This not only causes fluctuations in the heat transfer path (thermal resistance changes can reach 20-35%), but also accelerates material fatigue, leading to local hot spots and structural failure. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a new type of heat-conducting cable to solve the problems of heat transfer efficiency restricted by the anisotropy of graphite film and deformation coordination of multilayer graphite film.

[0007] This utility model solves the above-mentioned technical problems by adopting the following technical solution: a novel heat-conducting cable, comprising a heating device connection end, a flexible heat-conducting section, and a heat sink connection end. The flexible heat-conducting section is composed of a composite film of multiple layers of flexible high thermal conductivity graphite film and high thermal conductivity metal, stacked together. The thickness of the metal layer of the composite film is 0.05-0.5 times the thickness of the graphite film; during stacking, each layer of the composite film is aligned with its center line by positioning fixtures, and the parallelism error between layers is ≤0.05mm, to ensure synchronization during bending or deformation.

[0008] Furthermore, the graphite film is a single-layer high thermal conductivity graphite film folded along a centerline, with the folded edge connected to the connection end of the heating device and the open edge connected to the connection end of the heat sink. In the resulting double-layer structure, the upper and lower surfaces have regularly arranged through-holes with a pore size of 10μm to 1000μm. These through-holes are arranged in an array, with a spacing of 2-5 times the pore diameter and a porosity of 15-30%. The through-holes are perpendicular to the horizontal thermal conductivity direction of the graphite film, enhancing the vertical thermal conductivity path and simultaneously improving the bonding strength between the metal and the graphite film.

[0009] Furthermore, the high thermal conductivity metal may be one of gold, silver, copper, or aluminum.

[0010] Furthermore, the composite film can be prepared by electroplating, electroforming, magnetron sputtering, or liquid metal casting.

[0011] Furthermore, the connection between the flexible heat-conducting section and the connection end of the heating device and the heat sink is achieved by a molten metal casting process.

[0012] Furthermore, the multilayer composite film has regularly arranged through-holes at N (N=2~10) equal division points, as well as at the connections between the folded edges and openings of the composite film and the heating device and heat sink connections. The hole diameter is 1mm~5mm. The holes at the N equal division points are formed by depositing high thermal conductivity metal using an electroforming process to create interlayer connecting metal pillars. The holes at the connection points are formed by pouring liquid metal using a liquid metal casting process, and after cooling, the connection point and the heat-conducting section are integrally formed, thereby simultaneously enhancing the thermal conductivity and mechanical strength of the overall structure. The aspect ratio (height / diameter) of the metal pillars is 3:1 to 10:1, the pillar spacing is 2-4 times the pillar diameter, and they form a tight, integrated connection with the metal layers of each composite film.

[0013] The beneficial effects of adopting the above technical solution in this utility model are as follows:

[0014] 1. Traditional composite structures of high thermal conductivity graphite films and metals are limited by the anisotropy of high thermal conductivity graphite. The heat from the composite film is often concentrated only on the side in contact with the heat source, and is mainly transferred along the horizontal direction of the graphite film, resulting in a single heat transfer path and limited efficiency. This invention, however, uses a folded double-layer graphite film to form a composite structure with metal, and connects to the heating element via the folded edge. This design allows the heat from the composite film to be transferred simultaneously along both the upper and lower surfaces to the heat sink, effectively creating a dual parallel heat transfer channel. This significantly widens the heat transfer path and thus greatly improves the overall heat transfer performance of the composite film.

[0015] 2. By setting through-holes in the graphite film and through-holes at the division points of the multilayer composite film, as well as at the connection points between the folded edges and opening edges of the composite film and the connection points of the heating device and heat sink, an effective vertical heat conduction path is constructed, which significantly improves the heat transfer constraints caused by the anisotropy of the graphite film and improves the overall heat transfer efficiency.

[0016] 3. When stacking multilayer composite films, positioning fixtures are used to ensure centerline alignment. At the same time, metal pillars constrain each layer of the composite film, ensuring the synchronicity of the multilayer composite film when bending or deforming. This reduces interlayer misalignment and stress concentration, lowers heat transfer path fluctuations and material fatigue risks, and improves the service life and stability of the heat conduction cable. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a novel heat-conducting cable proposed in this utility model.

[0018] Figure 2 This is a schematic diagram of the composite membrane structure proposed in this utility model.

[0019] Figure 3 for Figure 2 A cross-sectional view taken along line AA.

[0020] Figure 4 This is a partial cross-sectional schematic diagram of the connection between the heating element connection end and the flexible heat-conducting section in this utility model.

[0021] Among them, 1 is the connection end of the heating device, 2 is the flexible heat-conducting section, 21 is the composite film, 22 is the interlayer metal pillar, 23 is the metal pillar located at the connection end, 3 is the heat sink connection end, 211 is the micropore penetrating the double-layer graphite film, 212 is the high thermal conductivity metal, 213 is the folded double-layer high thermal conductivity graphite film, 214 is the folded edge, and 215 is the open edge. Detailed Implementation

[0022] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Reference Figure 1-4As shown, this embodiment of a novel heat-conducting cable includes a heating device connection end 1, a flexible heat-conducting section 2, and a heat sink connection end 3. The flexible heat-conducting section 2 is composed of a composite film 21 of multiple layers of flexible high thermal conductivity graphite film 213 and high thermal conductivity metal 212 stacked together. The thickness of the high thermal conductivity metal 212 layer of the composite film 21 is 0.3 times the thickness of the graphite film 213. During stacking, each layer of the composite film 21 is aligned with its center line by positioning fixtures, and the parallelism error between layers is ≤0.05mm to ensure synchronization during bending or deformation.

[0025] Furthermore, the graphite film 213 is a single-layer high thermal conductivity graphite film folded along its centerline, with the folded edge 214 connected to the connection end 1 of the heating device and the open edge 215 connected to the connection end 3 of the heat sink. In the double-layer structure formed after folding, regularly arranged through-holes 211 with a pore diameter of 500 μm are present on the upper and lower surfaces. These through-holes are arranged in an array, with a spacing three times the pore diameter and a porosity of 20%. The through-holes 211 are perpendicular to the horizontal thermal conduction direction of the graphite film 213, enhancing the vertical thermal conduction path and simultaneously improving the bonding strength between the metal and the graphite film.

[0026] Furthermore, the high thermal conductivity metal 212 is copper.

[0027] Furthermore, the composite film 21 is prepared by electroplating.

[0028] Furthermore, the connection between the flexible heat-conducting section 2 and the heating device connection end 1 and the heat sink connection end 3 is made by molten metal casting process.

[0029] Furthermore, the multilayer composite film 21 has regularly arranged through holes at four equal division points, and at the connection points between the folded edges 214 and open edges 215 of the composite film 21 and the connection points with the heating device connection end 1 and the heat sink connection end 3. The hole diameter is 3mm. At each division point, high thermal conductivity metal is deposited through an electroforming process to form interlayer connecting metal pillars 22; at the connection ends, liquid metal is poured in through a liquid metal casting process to form metal pillars 23 located at the connection ends. After cooling, the connection ends and the heat-conducting sections are integrally formed, thereby simultaneously enhancing the thermal conductivity and mechanical strength of the overall structure. The aspect ratio (height / diameter) of the metal pillars is 5:1, the pillar spacing is 3 times the pillar diameter, and they form a tight, integrated connection with the metal layers of each composite film.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A novel heat-conducting cable, comprising a heating device connection end, a flexible heat-conducting section, and a heat sink connection end; characterized in that: The flexible heat-conducting section is composed of a composite film of multiple layers of flexible high thermal conductivity graphite film and high thermal conductivity metal through stacking. The thickness of the metal layer of the composite film is 0.05-0.5 times the thickness of the graphite film. During stacking, each layer of composite film is aligned with its center line by positioning fixtures, and the parallelism error between layers is ≤ 0.05mm to ensure synchronization during bending or deformation.

2. The novel heat-conducting cable according to claim 1, characterized in that, The graphite film is a single-layer high thermal conductivity graphite film folded along its centerline, with the folded edge connected to the heating device and the open edge connected to the heat sink. In the double-layer structure formed after folding, the upper and lower surfaces have regularly arranged through-holes with a pore size of 10μm to 1000μm. The through-holes are arranged in an array with a spacing of 2-5 times the pore size and a porosity of 15-30%. The through-holes are perpendicular to the horizontal thermal conduction direction of the graphite film, which can enhance the vertical thermal conduction path and improve the bonding strength between the metal and the graphite film.

3. The novel heat-conducting cable according to claim 1, characterized in that, The high thermal conductivity metal can be one of gold, silver, copper, or aluminum.

4. The novel heat-conducting cable according to claim 1, characterized in that, The composite film can be prepared by electroplating, electroforming, magnetron sputtering or liquid metal casting.

5. A novel heat-conducting cable according to claim 1, characterized in that, The connection between the flexible heat-conducting section and the connection end of the heating device and the heat sink is made by molten metal casting process.

6. A novel heat-conducting cable according to claim 1, characterized in that, The composite film is a multilayer composite film. At the N-division points, and at the connections between the composite film's folded edges, open edges, and the heating element / heat sink connection points, through-holes with diameters ranging from 1mm to 5mm are regularly arranged. The holes at the N-division points (N=2~10) are formed by depositing high thermal conductivity metal using an electroforming process, creating interlayer connecting metal pillars. The holes at the connection points are filled with liquid metal using a liquid metal casting process, and after cooling, the connection point and the heat-conducting section are integrally formed, thereby simultaneously enhancing the overall thermal conductivity and mechanical strength of the structure. The aspect ratio of the metal pillars (height to diameter ratio) is 3:1 to 10:1, the pillar spacing is 2-4 times the pillar diameter, and they form a tight, integrated connection with the metal layers of each composite film.

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