An elastic thermal conductor
By introducing a metal layer and a thermal adhesive layer into the elastic thermal conductor, the problem of excessive extrusion and insufficient thermal conductivity in the prior art is solved, and more efficient heat transfer and longer service life are achieved.
Patent Information
- Application Number
- CN202211052558.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-08-30
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2042-08-30
AI Technical Summary
The compression ratio of the existing elastic thermal conductor is too large when applying external force, resulting in excessive compression and bending of the graphite thermal conduction layer, affecting the thermal conductivity, and the thermal conductivity of the elastic foam is poor, limiting the overall thermal conductivity.
A structure including an elastic core and a metal layer is adopted, and the metal layer and the thermal conductivity layer are arranged laminated. The thickness of the metal layer accounts for 60% to 75% of the total thickness, and a cavity is formed inside the metal layer and filled with light thermal conductivity materials. , The thermally conductive adhesive layer is used to connect the thermally conductive layer and the interface, ensuring that the thermally conductive layer is not over-extruded and improving thermal conductivity.
The thermal conductivity of the thermal conductivity of the thermal conductivity layer is maintained, the overall thermal conductivity is improved, the service life is extended, and the heat transfer efficiency and thermal conductivity are improved by increasing the thermal conductivity path and filler.
Smart Images
Figure CN115379735B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of communication equipment, and in particular to an elastic heat conductor. Background Art
[0002] The heating element of electronic equipment, such as chips, will generate a lot of heat when working, which needs to be transferred to the heat dissipation component through the heat conduction component and dissipated through the heat dissipation component. For heat conduction between two interfaces with a large interval, the existing technology usually adopts the technical solution of elastic heat conductor. One end of the thermal conductive elastic fits tightly with the upper surface of the heating element, and the other end fits tightly with the heat dissipation component to achieve the heat dissipation effect.
[0003] Existing elastic thermal conductors usually include a graphite thermal conductive layer and an elastic foam. The graphite thermal conductive layer wraps the elastic foam, and the high thermal conductivity of graphite in the interface is used to achieve heat transfer, thereby achieving a thermal conductive effect between interfaces. However, the structural strength of the elastic foam is relatively low. When the external force applied is too large, the foam compression rate will exceed 25%, causing the graphite thermal conductive layer to be excessively squeezed and bent, greatly affecting the in-plane thermal conductivity. Secondly, the elastic foam itself has poor thermal conductivity, which limits the overall thermal conductivity of the elastic thermal conductor. Summary of the invention
[0004] The object of the present invention is to provide an elastic heat conductor.
[0005] In order to achieve the above object, the present invention provides an elastic heat conductor, which comprises: an elastic core, a heat conductive layer and a metal layer;
[0006] The elastic core and the metal layer are stacked along a first direction and are in contact with each other. The total thickness of the elastic thermal conductor is M, the thickness of the metal layer is N, the thickness of the elastic core is L, the compression rate of the elastic core is Y, and the compression rate of the elastic thermal conductor is Z;
[0007] in,
[0008] N ≥ 0.5M;
[0009] The heat-conducting layer wraps the elastic core and the metal layer, and the heat-conducting layer has a first end face and a second end face that are arranged opposite to each other, the first end face is used to abut against a first interface, the second end face is used to abut against a second interface, and the first direction is from the first end face to the second end face;
[0010] The two side surfaces of the metal layer parallel to the first direction abut against the heat conducting layer.
[0011] In some embodiments of the present application, the ratio of the thickness N of the metal layer to the total thickness M of the elastic thermal conductor is 60% to 75%.
[0012] In some embodiments of the present application, a cavity is formed inside the metal layer.
[0013] In some embodiments of the present application, a filling body is further included, wherein the filling body is filled in the cavity, and the filling body is at least one of EVA foam and phase change thermal storage material.
[0014] In some embodiments of the present application, the metal layer is at least one of gold, silver, copper, aluminum or aluminum nitride.
[0015] In some embodiments of the present application, the thermal conductive layer is at least one of natural graphite, artificial graphite, and graphene.
[0016] In some embodiments of the present application, the elastic core is at least one of elastic foam, electroplated foam or elastic metal wire.
[0017] In some embodiments of the present application, the heat-conducting layer defines a receiving groove, the elastic core and the heat-conducting layer are arranged in the receiving groove and abut against the cavity wall of the receiving groove, and the receiving groove has a notch portion communicating with the second end surface;
[0018] The elastic heat conductor also includes a first heat conductive adhesive layer, which is penetrated in the notch and used to connect the heat conductive layer and the second interface.
[0019] In some embodiments of the present application, the first thermally conductive adhesive layer is at least one of acrylic adhesive and silicone adhesive.
[0020] In some embodiments of the present application, a second thermally conductive adhesive layer is further included, and the second thermally conductive adhesive layer is disposed between the metal layer and the thermally conductive layer to connect the two.
[0021] The present invention provides an elastic heat conductor, which has the following advantages compared with the prior art:
[0022] The elastic heat conductor provided by the present invention comprises an elastic core, a heat-conducting layer and a metal layer. The elastic core and the metal layer are stacked along a first direction and are in contact with each other. Since the metal layer, which is an incompressible layer, is added and the thickness ratio of the elastic core, which is a compressible layer, and the metal layer is controlled, the overall compression rate of the elastic heat conductor can be maintained within a predetermined range, thereby preventing the heat-conducting layer from being excessively squeezed and bent, and ensuring the in-plane heat conduction capacity of the heat-conducting layer. Secondly, since the metal layer has a high thermal conductivity, compared with the original situation where heat can only be conducted through the heat-conducting layer and heat is slowly conducted in the elastic core, in the present application, heat can be transferred through the heat-conducting layer and the metal layer, and the thickness of the elastic core is greatly reduced, so the heat transfer efficiency is greatly improved, the overall heat conduction capacity is improved, and the heat conduction effect is optimized. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 is a schematic cross-sectional view of an elastic heat conductor according to an embodiment of the present invention;
[0024] Figure 2 is a schematic cross-sectional view of an elastic heat conductor according to another embodiment of the present invention;
[0025] Figure 3 FIG. 4 is a schematic cross-sectional view of an elastic heat conductor according to another embodiment of the present invention.
[0026] In the figure: 1, heat-conducting layer; 11, first end face; 12, second end face; 13, receiving groove; 14, notch; 2, elastic core; 3, metal layer; 31, cavity; 4, filling body; 5, first heat-conducting adhesive layer. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.
[0028] It should be understood that, in the description of the present application, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, that is, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, unless otherwise specified, "multiple" means two or more.
[0029] It should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0030] like Figure 1-3 As shown, an embodiment of the present invention provides an elastic thermal conductor, which includes an elastic core 2 , a thermal conductive layer 1 and a metal layer 3 .
[0031] The elastic core 2 and the metal layer 3 are stacked along the first direction A and are in contact with each other. The total thickness of the elastic thermal conductor is M, the thickness of the metal layer 3 is N, the thickness of the elastic core 2 is L, the compression rate of the elastic core 2 is Y, and the maximum compression rate of the elastic thermal conductor is Z.
[0032] in,
[0033] N ≥ 0.5M;
[0034]
[0035] Z is 22% to 28%;
[0036] The heat-conducting layer 1 wraps the elastic core 2 and the metal layer 3, and has a first end face 11 and a second end face 12 that are oppositely arranged, the first end face 11 is used to abut against the first interface, and the second end face 12 is used to abut against the second interface, and the first direction A is from the first end face 11 to the second end face 12;
[0037] The two side surfaces of the metal layer 3 parallel to the first direction A are in contact with the heat conducting layer 1. Preferably, the ratio of the thickness N of the metal layer to the total thickness M of the elastic heat conductor is 60% to 75%, wherein 60%, 65%, 70% and 75% are preferred values of the thickness ratio.
[0038] Specifically, the heat-conducting layer 1 is formed with a receiving groove 13, and the elastic core 2 and the heat-conducting layer 1 are arranged in the receiving groove 13 and abut against the cavity wall of the receiving groove 13, so as to facilitate heat conduction. The thickness of the end walls at both ends where the first end face 11 and the second end face 12 of the heat-conducting layer 1 are located is extremely small, generally not exceeding 0.1 mm, so it will not affect the thickness ratio control of the elastic heat conductor.
[0039] In this embodiment, the direction opposite to the first direction A is the direction of heat transfer, the first interface is the component end surface on the downstream side of the elastic heat conductor in the direction of heat transfer, and the second interface is the component end surface on the upstream side of the elastic heat conductor in the direction of heat transfer. Of course, the direction opposite to the first direction A may also be the direction of heat transfer, the first interface is the component end surface on the upstream side of the elastic heat conductor in the direction of heat transfer, and the second interface is the component end surface on the downstream side of the elastic heat conductor in the direction of heat transfer.
[0040] Based on the above structure, since the metal layer 3, an incompressible layer, is added, an elastic core 2 with a suitable compression rate is provided, and the thickness ratio of the elastic core 2, a compressible layer, and the metal layer 3 are controlled, the overall compression rate of the elastic thermal conductor can be maintained within a predetermined range, preventing the thermal conductive layer 1 from being excessively squeezed and bent, thereby ensuring the in-plane thermal conductivity of the thermal conductive layer 1, and the thickness ratio of the metal layer 3 enables the elastic thermal conductor to obtain a larger heat flux and a higher heat transfer efficiency.
[0041] In the prior art, when heat is transferred through the heat-conducting layer 1, the elastic core 2 itself has poor thermal conductivity, which makes it difficult for heat to be transferred through the elastic core 2. In the present application, since the metal layer 3 has high thermal conductivity, compared with the original situation where heat can only be conducted through the heat-conducting layer 1 and heat is slowly conducted in the elastic core 2, in the present application, heat can be transferred through the heat-conducting layer 1 and the metal layer 3, and the thickness of the elastic core 2 is greatly reduced, and the heat conduction path is increased. Heat can be conducted directly through the heat-conducting layer 1, or through the heat-conducting layer 1-metal layer 3-heat-conducting layer 1, and heat can also be conducted through the heat-conducting layer 1-metal layer 3-elastic core 2-heat-conducting layer 1. Therefore, the heat transfer efficiency is greatly improved, the overall thermal conductivity is improved, and the thermal conduction effect is optimized. Compared with the setting method of wrapping the elastic core 2 with the metal layer 3, the elastic thermal conductor in the present application is not easy to deform during the extrusion process on the basis of ensuring the thermal conductivity, and the service life of the elastic thermal conductor is longer.
[0042] Alternatively, if Figure 1 As shown, in this embodiment, the maximum compression rate Z of the elastic heat conductor is 24% to 26%, wherein 24%, 25% and 26% are preferred values of the compression rate.
[0043] In order to demonstrate the effects of adding the metal layer 3 and controlling the thickness ratio on the elastic thermal conductor, the applicant conducted the following comparative experiments:
[0044] According to ASTM D5470, the thermal conductivity of thermal insulation materials is tested by converting the thermal resistance into the corresponding thermal conductivity according to the Fourier formula. The thermal conductivity k is calculated by the following formula:
[0045]
[0046] k is thermal conductivity, Q is heat, t is time, L is length, A is area; T is temperature difference.
[0047]
[0048] Table 1
[0049] As can be seen from Table 1, when the thickness ratio of the metal layer is between 60% and 75%, the thermal conductivity is 6.5W / (m·K) to 7.0W / (m·K), which is 30% to 40% higher than the thermal conductivity of 5W / (m·K) when only the elastic core layer is set. In other words, the thermal conductivity is greatly improved. Moreover, when the thickness of the metal layer accounts for 75%, it can ensure that the maximum compression rate of the elastic thermal conductor does not exceed 25%, so that the thermal conductivity of the thermal conductive layer is better, and the overall thermal conductivity is higher.
[0050] Alternatively, if Figure 2As shown, in another embodiment, a cavity 31 is formed inside the metal layer 3. Thus, the provision of the cavity 31 reduces the weight of the metal layer 3, thereby reducing the overall weight of the elastic thermal conductor, making it lighter.
[0051] Alternatively, if Figure 3 As shown, in another embodiment, the elastic thermal conductor further includes a filler 4, which is filled in the cavity 31. The filler 4 is at least one of EVA (ethylene-vinyl acetate copolymer) foam and phase change thermal storage material. In this way, the foam and / or phase change thermal storage material are relatively light, and can absorb and store more heat while ensuring that the overall weight of the elastic thermal conductor is relatively small, thereby further improving the thermal conductivity.
[0052] Alternatively, if Figure 1 As shown, in this embodiment, the metal layer 3 is at least one of gold, silver, copper, aluminum or aluminum nitride. In this way, the metal layer 3 has a high thermal conductivity, which is convenient for heat transfer.
[0053] Alternatively, if Figure 1 As shown, in this embodiment, the heat conducting layer 1 is at least one of natural graphite, artificial graphite, and graphene.
[0054] Alternatively, if Figure 1 As shown, in this embodiment, the elastic core 2 is at least one of elastic foam, electroplated foam or elastic metal wire. Specifically, the elastic foam can be silicone rubber, polyurethane sponge, PU foam or rubber foam, etc. When part or all of the elastic core 2 is constructed of elastic metal wire, the thermal conductivity of the elastic thermal conductor is further enhanced.
[0055] In the prior art, the heat-conducting layer 1 is usually arranged to completely wrap the elastic core 2, and a heat-conducting adhesive layer is arranged between the second end surface 12 of the heat-conducting layer 1 and the second interface, so that the heat-conducting layer 1 and the second interface cannot be in direct contact, the heat-conducting path is longer, and the thermal conductivity is reduced. Based on this, optionally, as Figure 1 As shown, in this embodiment, the receiving groove 13 has a notch portion 14 connected to the second end face 12, and the elastic heat conductor also includes a first heat-conducting adhesive layer 5, which is inserted into the notch portion 14 and is used to connect the heat-conducting layer 1 and the second interface. In this way, the heat-conducting adhesive layer does not completely cover or does not completely cover the second end face 12, so that heat can be directly transferred from the second interface to the second end face 12 of the heat-conducting layer 1, the heat conduction path is shortened, and the thermal conductivity is improved. Secondly, the heat-conducting adhesive layer extends into the receiving groove 13 to assist in connecting and fixing the heat-conducting layer 1 and the metal layer 3, so that the connection between the metal layer 3 and the heat-conducting layer 1 is more stable.
[0056] Alternatively, if Figure 1As shown, in this embodiment, the first thermally conductive adhesive layer 5 is at least one of acrylic adhesive and silicone adhesive.
[0057] Optionally, in this embodiment, the elastic heat conductor further includes a second heat-conducting adhesive layer (not shown in the figure), which is disposed between the metal layer 3 and the heat-conducting layer 1 and connects the two. Specifically, the second heat-conducting adhesive layer is in the form of an adhesive film, which is completely in contact with the inner wall of the receiving groove 13 and the side surface of the metal layer 3. Preferably, an insulating film is provided on the outer surface of the heat-conducting layer 1. Further, the second heat-conducting adhesive layer extends between the elastic core 2 and the heat-conducting layer 1 and connects the two.
[0058] In summary, the embodiment of the present invention provides an elastic thermal conductor, which is mainly composed of an elastic core 2, a thermal conductive layer 1 and a metal layer 3. The elastic core 2 and the metal layer 3 are stacked along a first direction A and abut against each other. The thermal conductive layer 1 wraps the elastic core 2 and the metal layer 3. The thermal conductive layer 1 has a first end face 11 and a second end face 12 that are arranged opposite to each other. The first end face 11 is used to abut against the first interface, and the second end face 12 is used to abut against the second interface. The first direction A is from the first end face 11 to the second end face 12; the two side surfaces of the metal layer 3 parallel to the first direction A abut against the thermal conductive layer 1. Compared with the prior art, the elastic thermal conductor has the following advantages:
[0059] 1. Due to the addition of an incompressible metal layer, an elastic core with a suitable compression rate is provided, and the thickness ratio of the compressible elastic core and the metal layer is controlled, the overall compression rate of the elastic thermal conductor can be maintained within a predetermined range, preventing the thermal conductive layer from being excessively squeezed and bent, thereby ensuring the in-plane thermal conductivity of the thermal conductive layer. In addition, the thickness ratio of the metal layer enables the elastic thermal conductor to obtain a larger heat flux and a higher heat transfer efficiency.
[0060] 2. Since the metal layer has high thermal conductivity, compared with the original situation where heat can only be conducted through the thermal conductive layer and heat is slowly conducted in the elastic core, in this application, heat can be transferred through the thermal conductive layer and the metal layer, and the thickness of the elastic core is greatly reduced, and the heat conduction path is increased. Heat can be conducted directly through the thermal conductive layer, or through the thermal conductive layer-metal layer-thermal conductive layer, or through the thermal conductive layer-metal layer-elastic core-thermal conductive layer. Therefore, the heat transfer efficiency is greatly improved, the overall thermal conductivity is improved, and the thermal conduction effect is optimized. Compared with the setting method of wrapping the elastic core with a metal layer, the elastic thermal conductor in this application ensures the thermal conductivity, and the metal layer is not easy to deform during the extrusion process, and the service life of the elastic thermal conductor is longer.
[0061] 3. The metal layer is provided with a cavity filled with a filler made of a lightweight material and capable of conducting heat, which can absorb and store more heat while ensuring that the overall weight of the elastic thermal conductor is small, thereby further improving the thermal conductivity.
[0062] 4. The thermally conductive adhesive layer does not completely cover or does not cover the second end surface at all, so that heat can be directly transferred from the second interface to the second end surface of the thermally conductive layer, shortening the thermal conduction path and improving the thermal conductivity; secondly, the thermally conductive adhesive layer extends into the receiving groove to assist in connecting and fixing the thermally conductive layer and the metal layer, making the connection between the metal layer and the thermally conductive layer more stable.
[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.
Claims
1. An elastic thermal conductor, It is characterized in that include: An elastic core, a heat conductive layer, a filler and a metal layer; The elastic core and the metal layer are stacked along a first direction and are in contact with each other. The total thickness of the elastic heat conductor is M, and the thickness of the metal layer is N. The ratio of the thickness N of the metal layer to the total thickness M of the elastic thermal conductor is 60% to 75%; The heat-conducting layer wraps the elastic core and the metal layer, and the heat-conducting layer has a first end face and a second end face that are arranged opposite to each other, the first end face is used to abut against a first interface, the second end face is used to abut against a second interface, and the first direction is from the first end face to the second end face; The two side surfaces of the metal layer parallel to the first direction are in contact with the heat conducting layer. A cavity is formed inside the metal layer, and the filling body is filled in the cavity.
2. The elastic heat conductor according to claim 1, Features: The filler is at least one of EVA foam and phase change thermal storage material.
3. The elastic heat conductor according to claim 1, Features: The metal layer is at least one of gold, silver, copper, aluminum or aluminum nitride.
4. The elastic thermal conductor according to claim 1, Features: The heat-conducting layer is at least one of natural graphite, artificial graphite and graphene.
5. The elastic heat conductor according to claim 1, Features: The elastic core is at least one of elastic foam, electroplated foam or elastic metal wire.
6. The elastic heat conductor according to claim 1, Features: The heat-conducting layer defines a receiving groove, the elastic core and the heat-conducting layer are arranged in the receiving groove and abut against the cavity wall of the receiving groove, and the receiving groove has a notch portion communicating with the second end surface; The elastic heat conductor also includes a first heat conductive adhesive layer, which is penetrated in the notch and used to connect the heat conductive layer and the second interface.
7. The elastic heat conductor according to claim 6, Features: The first thermally conductive adhesive layer is at least one of acrylic adhesive and silicone adhesive.
8. The elastic thermal conductor according to claim 1, Features: It also includes a second thermally conductive adhesive layer, which is arranged between the metal layer and the thermally conductive layer and connects the two.