Temperature balancing plate and method for preparing the same

Abstract

The present invention relates to a temperature averaging plate and a method for preparing the temperature averaging plate, wherein the temperature averaging plate comprises a cover plate, a heat-conducting interlayer and a bottom plate, wherein the cover plate and the bottom plate together form a cavity, wherein the heat-conducting interlayer is arranged in the cavity; the heat-conducting interlayer comprises a first surface and a second surface opposite to each other, wherein the first surface is connected to the inner surface of the cover plate, and the second surface is connected to the inner surface of the bottom plate; and reinforcing ribs protruding outward are arranged on the outer surface of the cover plate. The present invention can reduce the overall thickness and weight of the temperature averaging plate, and improve the structural strength and temperature averaging effect of the temperature averaging plate.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of temperature averaging plates, and specifically relates to a temperature averaging plate and a method for preparing the temperature averaging plate. Background Art

[0002] With the rapid development of aerospace vehicles and electronic information, the functional and performance requirements of aerospace payload equipment are increasing, and the highly integrated and complex chips inside them will generate more heat. The high-power chips of complex integrated circuits are usually concentrated in one or several areas of the printed circuit board, which can easily cause the chip junction temperature to exceed its safe use range, greatly affecting the on-orbit operation life of the spacecraft. In order to keep the temperature of the spacecraft within a reasonable temperature control range, the high-power chips of the satellite payload equipment are usually connected to the temperature plate to dissipate heat.

[0003] Figure 1 This is a cross-sectional view of an existing graphene temperature plate. Figure 1 As shown, graphene is provided in the existing heat spreader, and a cylindrical or rectangular aluminum connecting part is provided in the interlayer of the heat spreader to connect the upper cover and the lower cover of the heat spreader. The in-plane thermal conductivity of graphene is higher than the normal thermal conductivity. Figure 1 The temperature equalizer shown can transfer heat from the cover plate to the graphene to achieve temperature equalization. However, the contact area between this type of connection and the graphene is limited, and the heat dissipation effect is not good. If too many connection structures are provided, the weight of the temperature equalizer will increase significantly.

[0004] At present, the common weight reduction method used for heat spreaders in aerospace payload equipment is to reduce the thickness of the cover plate. However, for graphene heat spreaders, thinner plate thickness will reduce the graphene filling amount in the heat spreader interlayer and reduce the contact area between graphene and the connection part, which will reduce its temperature equalization performance and increase the manufacturing difficulty and cost. The heat spreaders currently used in spacecraft have the problems of heavy weight and poor temperature equalization effect. Due to the limitation of the overall design weight of the satellite payload, the heat spreader needs to be optimized to explore the balance between weight reduction and heat dissipation of the heat spreader. Summary of the invention

[0005] The technical problem to be solved by the present application is to provide a temperature averaging board and a method for preparing the temperature averaging board, which can reduce the overall thickness and weight of the temperature averaging board and improve the structural strength and temperature averaging effect of the temperature averaging board.

[0006] The technical solution adopted by the present application to solve the above-mentioned technical problems is a temperature equalizing plate, including a cover plate, a heat-conducting interlayer and a bottom plate, the cover plate and the bottom plate together form a cavity, and the heat-conducting interlayer is arranged in the cavity; the heat-conducting interlayer includes a first surface and a second surface relative to each other, the first surface is connected to the inner surface of the cover plate, and the second surface is connected to the inner surface of the bottom plate; the outer surface of the cover plate is provided with reinforcing ribs protruding outward.

[0007] In one embodiment of the present application, the thermally conductive interlayer is a graphene interlayer.

[0008] In one embodiment of the present application, a groove is provided in the reinforcing rib, the groove is connected to the inner surface of the cover plate, and the opening of the groove faces the heat-conducting interlayer; a protrusion is provided on the first surface, and the protrusion and the groove are in contact with each other.

[0009] In one embodiment of the present application, the thickness of the reinforcing rib is 2.5 mm to 5 mm, and the depth of the groove is 0.5 mm to 1.5 mm less than the thickness of the reinforcing rib, where mm represents millimeter.

[0010] In one embodiment of the present application, a bevel is provided on the edge of the groove, the groove is connected to the inner surface of the cover plate through the bevel, and the angle between the bevel and the inner surface of the cover plate is an acute angle.

[0011] In one embodiment of the present application, there are multiple reinforcing ribs, and the multiple reinforcing ribs are cross-distributed.

[0012] In one embodiment of the present application, heat-conducting columns facing the heat-conducting interlayer are arranged at the intersection of the grooves, and the height of the heat-conducting columns is flush with the inner surface of the cover plate.

[0013] In one embodiment of the present application, a thermally conductive boss facing the heat-conducting column is provided on the inner surface of the base plate, and a through hole is provided on the thermally conductive interlayer. The thermally conductive boss, the through hole, and the heat-conducting column correspond to each other one by one, and the thermally conductive boss is connected to the heat-conducting column through the through hole; the outer surface of the base plate is used to connect with external components, and the distribution position of the thermally conductive boss corresponds to the heat-generating position of the external component.

[0014] In one embodiment of the present application, the cover plate and / or the bottom plate are made of aluminum alloy.

[0015] In order to solve the above technical problems, the present application also proposes a method for preparing a temperature equalizing plate, which is used to prepare the above temperature equalizing plate, comprising: preparing a base plate by a machining method, and setting a heat-conducting boss on the inner surface of the base plate, wherein the distribution position of the heat-conducting boss corresponds to the heat-generating position of the external component; preparing a cover plate by a machining method, and setting a plurality of cross-distributed reinforcing ribs on the outer surface of the cover plate; marking positions corresponding to the plurality of reinforcing ribs on the inner surface of the cover plate, and machining grooves at the positions so that the grooves are located inside the reinforcing ribs; setting heat-conducting columns at the intersections of the grooves; machining a chamfer at the edge of the grooves; grinding the base plate and the cover plate to a preset thickness; The surface of the cover plate and the surface of the cover plate are anodized and / or metal-plated to form an isolation layer; the graphene oxide film is dried, heated, and machined to obtain a graphene interlayer, and the graphene interlayer is interference-fitted into the inner surface and groove of the cover plate; solder is applied on the edge of the inner surface of the cover plate and on the contact surface of the heat-conducting column and the base plate; the inner surface of the base plate and the inner surface of the cover plate are assembled and docked, and the heat-conducting boss is fitted with the contact surface of the heat-conducting column; solder is filled in the side gap between the base plate and the cover plate; the cover plate, the graphene interlayer and the base plate are pressed, heated, and polished to form a temperature-averaging plate.

[0016] The technical solution of the present application can reduce the overall thickness and weight of the temperature equalizer by setting the heat-conducting interlayer in the cavity surrounded by the cover plate and the bottom plate; the heat-conducting effect and the temperature equalization effect can be improved by connecting the cover plate, the heat-conducting interlayer and the bottom plate; the structural strength and rigidity of the temperature equalizer can be improved by setting reinforcing ribs on the outer surface of the cover plate, and the design thickness of the cover plate can be made thinner when the mechanical requirements do not change, which is helpful for the weight reduction design of satellite payload equipment. The temperature equalizer of the present application can adapt to the weight reduction, temperature equalization and heat dissipation, and structural strength reliability requirements of spacecraft payloads, and at the same time provides a design idea for thinner aerospace temperature equalizers, which can achieve the optimization of heat dissipation, weight reduction and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings, wherein:

[0018] Figure 1 It is a cross-sectional view of an existing graphene temperature-averaging plate;

[0019] Figure 2 This is a schematic diagram of the overall structure of a temperature homogenizing plate according to an embodiment of the present application;

[0020] Figure 3 is an exploded view of a temperature homogenizing plate according to an embodiment of the present application;

[0021] Figure 4 is a schematic diagram of the inner surface of the cover plate in one embodiment of the present application;

[0022] Figure 5 is a cross-sectional view of a bottom plate, a heat-conducting interlayer, and a cover plate in an embodiment of the present application when they are not in full contact;

[0023] Figure 6 is a schematic diagram of a groove and an inclined surface in a reinforcing rib in an embodiment of the present application;

[0024] Figure 7 is a cross-sectional view of a groove and an inclined surface in an embodiment of the present application;

[0025] Figure 8 This is a schematic diagram of the junction temperature change of the main chip of the satellite payload equipment obtained after using the temperature equalization board of the present application;

[0026] Fig. 9 This is a schematic diagram of the comparison results of the heat dissipation performance at characteristic positions of a satellite when it is in orbit, obtained after using the temperature homogenizing plate of the present application.

[0027] Description of the accompanying drawings in the specific implementation manner:

[0028] 1. Cover plate; 11. Protrusion; 100. Temperature equalizing plate; 2. Bottom plate; 3. Thermally conductive interlayer; 31. First surface; 32. Through hole; 4. Reinforcement rib; 5. Thermally conductive boss; 6. Groove; 7. Thermally conductive column; 8. Inclined surface; S1. Outer surface of the cover plate; S2. Inner surface of the cover plate; S3. Inner surface of the bottom plate; S4. Outer surface of the bottom plate. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and therefore the present application is not limited to the specific embodiments disclosed below.

[0031] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0032] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0033] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0034] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0035] Below, the embodiments of the present application are described based on the accompanying drawings. However, the embodiments shown below are examples of temperature averaging plates and temperature averaging plate preparation methods for concretizing the technical ideas of the present application, and the temperature averaging plates and temperature averaging plate preparation methods of the present application are not specific to the following contents. Furthermore, in order to facilitate the understanding of the scope of the claims, this specification assigns numbers corresponding to the components shown in the embodiments to the components shown in the "Claims" and "Application Contents" columns. However, the components shown in the claims are by no means specific to the components of the embodiments. In particular, the size, material, shape, and relative configuration of the constituent components recorded in the embodiments, if there is no specific record, is not intended to limit the scope of the present application to this, but is just an illustrative example.

[0036] However, the dimensions or positional relationships of the components shown in the drawings are sometimes exaggerated for the purpose of clarifying the description. Furthermore, in the following description, for the same names and symbols, representing the same or homogeneous components, it is appropriate to omit their detailed description. Furthermore, the various elements constituting the present application may be in the form of a plurality of elements constituted by the same components so that one component serves as a plurality of elements, or conversely, it may be realized by a plurality of components sharing the function of a component. In addition, the contents described in some embodiments and implementation methods may also be utilized in other embodiments, implementation methods, etc. In addition, in this specification, "on" is not limited to the case where it is formed in contact with the upper surface, but also includes the case where it is formed separately on the upper surface, and is also used to include the meaning of the existence of an intervening layer between layers.

[0037] The present application proposes a temperature homogenizing plate, which can be used in the temperature homogenizing heat dissipation scenario of satellite payload components (such as chips).

[0038] Figure 2 is a schematic diagram of the overall structure of a temperature homogenizing plate according to an embodiment of the present application. Figure 3 is an exploded view of a temperature homogenizing plate according to an embodiment of the present application. Figure 2 and Figure 3 As shown, the temperature equalizing plate 100 of this embodiment includes a cover plate 1, a thermally conductive interlayer 3 and a bottom plate 2, the cover plate 1 and the bottom plate 2 together form a cavity (not shown), and the thermally conductive interlayer 3 is arranged in the cavity; the thermally conductive interlayer 3 includes a first surface 31 (i.e., an upper surface) and a second surface (i.e., a lower surface) relative to each other, the first surface 31 is connected to the inner surface S2 of the cover plate, and the second surface is connected to the inner surface S3 of the bottom plate; the outer surface S1 of the cover plate is provided with reinforcing ribs 4 protruding outward.

[0039] In some embodiments, the thermally conductive interlayer 3 is a graphene interlayer. In practical applications, the thermally conductive interlayer 3 can also be prepared using metal-based composite materials, phase-change thermally conductive materials, polymer thermally conductive materials, etc., and the present application does not limit the material of the thermally conductive interlayer 3. The present application uses a graphene interlayer as the thermally conductive interlayer 3 to introduce the technical solution of the present application.

[0040] For example, reference Figure 2 and Figure 3 As shown, the main structure of the temperature equalizer 100 includes a cover plate 1, a heat-conducting interlayer 3 and a bottom plate 2. A cavity is formed between the cover plate 1 and the bottom plate 2, and the cavity is filled with graphene to form a graphene interlayer. The cover plate 1, the heat-conducting interlayer 3 and the bottom plate 2 are packaged together to form the overall structure of the temperature equalizer 100. The temperature equalizer 100 of the present application can be designed as a regular shape or an irregular shape, such as a rectangle, a triangle, a circle, a regular polygon, an irregular polygon, etc.

[0041] The technical solution of the present application can reduce the overall thickness and weight of the temperature equalizing plate 100 by arranging the heat-conducting interlayer 3 in the cavity enclosed by the cover plate 1 and the bottom plate 2; the heat-conducting effect and the temperature equalizing effect can be improved by connecting the cover plate 1, the heat-conducting interlayer 3 and the bottom plate 2; the structural strength and rigidity of the temperature equalizing plate 100 can be improved by arranging reinforcing ribs 4 on the outer surface S1 of the cover plate, and the design thickness of the cover plate 1 can be made thinner when the mechanical requirements do not change, which is helpful for the weight reduction design of satellite payload equipment. The temperature equalizing plate 100 of the present application can adapt to the weight reduction, temperature equalization and heat dissipation, and structural strength reliability requirements of spacecraft payloads, and at the same time provide design ideas for thinner aerospace temperature equalizing plates, which can achieve the optimization of heat dissipation, weight reduction and economic benefits.

[0042] In some embodiments, the cover plate 1 and / or the bottom plate 2 are made of aluminum alloy. For example, in actual production, the same type of aluminum alloy can be used to prepare the cover plate 1 and the bottom plate 2. The heat spreader 100 of the present application is equivalent to a high-performance "aluminum-graphene heat spreader".

[0043] Figure 4 Schematic diagram of the inner surface of the cover plate in one embodiment of the present application. Figure 3 and Figure 4 As shown, in some embodiments, the number of reinforcing ribs 4 is multiple, and the multiple reinforcing ribs 4 are cross-distributed. In some embodiments, a groove 6 is provided in the reinforcing rib 4, the groove 6 is connected to the inner surface S2 of the cover plate, and the opening of the groove 6 faces the heat-conducting interlayer 3; a protrusion 11 is provided on the first surface 31, and the protrusion 11 and the groove 6 are in contact.

[0044] Exemplarily, the material of the protrusion 11 is graphene. Based on the anisotropic thermal conductivity of graphene, the present application improves the sandwich structure and graphene distribution of the heat spreader 100, and by providing a groove 6 inside the reinforcing rib 4 and filling it with a graphene interlayer, the in-plane thermal conductivity (i.e., temperature equalization capability) and normal (direction perpendicular to the plane) thermal conductivity of the graphene heat spreader 100 of the same thickness are improved.

[0045] In some embodiments, the thickness of the reinforcing rib 4 is 2.5 mm to 5 mm, and the depth of the groove 6 is 0.5 mm to 1.5 mm less than the thickness of the reinforcing rib 4, where mm represents millimeters. Exemplarily, the thickness of the reinforcing rib 4 is preferably set to 3 mm to 4 mm. The present application sets the thickness of the reinforcing rib 4 to 3 mm, and sets the depth of the groove 6 to 0.5 mm less than the thickness of the reinforcing rib 4, that is, the depth of the groove 6 is 2.5 mm. The present application can ensure the structural strength requirements of the cover plate 1 by designing the thickness of the reinforcing rib 4 and the depth of the groove 6.

[0046] Figure 6 is a schematic diagram of the groove and the inclined surface in the reinforcing rib in one embodiment of the present application, Figure 7is a cross-sectional view of a groove and an inclined surface in an embodiment of the present application. Figure 6 and Figure 7 As shown, in some embodiments, the edge of the groove 6 is provided with a bevel 8, the groove 6 is connected to the inner surface S2 of the cover plate through the bevel 8, and the angle between the bevel 8 and the inner surface S2 of the cover plate is an acute angle (such as Figure 7 Angle A) shown in FIG.

[0047] Exemplarily, the inclined surface 8 between the bottom surface of the groove 6 and the inner surface S2 of the cover plate is equivalent to the transitional inclined surface 8 of the groove 6. The present application can increase the thermal contact area between the graphene and the cover plate 1 by setting the inclined surface 8, thereby enhancing the normal thermal conductivity of the graphene temperature balancing plate 100. The angle A between the inclined surface 8 and the inner surface S2 of the cover plate can be set in the range of 30° to 60°. Considering the structural size limitation, the optimal design angle of the angle A is 40° to 50°. The present application does not limit the value of the angle A.

[0048] Figure 5 This is a cross-sectional view of an embodiment of the present application when the bottom plate, the heat conductive interlayer, and the cover plate are not in full contact. Figures 3 to 5 As shown, in some embodiments, a heat-conducting column 7 facing the heat-conducting interlayer 3 is provided at the intersection of the groove 6, and the height of the heat-conducting column 7 is flush with the inner surface S2 of the cover plate. For example, the heat-conducting column 7 can be set as a cylinder or an elliptical cylinder, and the present application does not limit the shape of the heat-conducting column 7.

[0049] In some embodiments, a thermally conductive boss 5 facing the thermally conductive column 7 is provided on the inner surface S3 of the base plate, and a through hole 32 is provided on the thermally conductive interlayer 3. The thermally conductive boss 5, the through hole 32, and the thermally conductive column 7 correspond one to one, and the thermally conductive boss 5 is connected to the thermally conductive column 7 through the through hole 32; the outer surface S4 of the base plate is used to connect with an external component (not shown), and the distribution position of the thermally conductive boss 5 corresponds to the heat generation position of the external component.

[0050] refer to Figure 5 As shown, for example, the heat-conducting boss 5 is a solid structure, and the cross-sectional size and shape of the heat-conducting boss 5 and the heat-conducting column 7 can be set to be the same. During the overall assembly of the temperature-vaporizing plate 100, after the heat-conducting boss 5 passes through the through hole 32, the surface of the heat-conducting boss 5 fits with the surface of the heat-conducting column 7. The distribution position of the heat-conducting boss 5 on the bottom plate 2 can correspond to the high heat consumption component area of ​​the spacecraft, for example, every 80cm 2 Up to 100cm 2 Arrange a cross-sectional area no greater than 12cm 2The heat-conducting boss 5 can be arranged according to the layout of the high-heat-consumption chip on the printed circuit board. In the present application, the heat-conducting boss 5 of the bottom plate 2 and the heat-conducting column 7 of the cover plate 1 are welded into an integrated structure by solder, and the side surfaces of the two are in contact with the graphene as the heat-conducting surface. This arrangement can solve the problem that heat is difficult to be directly transferred to the graphene in the normal direction, and greatly increases the heat-conducting capacity of the graphene temperature-averaging plate 100 in the direction of the surface and the normal direction.

[0051] The beneficial effects brought about by the designs of the base plate 2 and the cover plate 1 of the present application are collectively described here.

[0052] Regarding the design of the bottom plate 2: In practical applications, a clamping boss can also be set on the outer surface S4 of the bottom plate, and the heat of the chip and the heat consumption element is transferred to the aluminum alloy bottom plate 2 via the clamping boss on the outer surface of the bottom plate 2. The design of the heat-conducting boss 5 close to the outer surface clamping boss can reduce the heat conduction resistance of the path. Considering that the thermal conductivity coefficient inside the graphene sandwich layer is much higher than the normal direction, the present application designs a truncated cone-shaped heat-conducting boss 5, whose side surface contacts the graphene as a heat-conducting surface, which not only increases the heat-conducting contact area, but also solves the problem that heat is difficult to be directly transferred to the graphene along the normal direction.

[0053] Regarding the design of the cover plate 1: the cross-sectional size and shape of the heat-conducting boss 5 of the base plate 2 and the heat-conducting column 7 of the cover plate 1 are equal, and the two are in contact with each other and form an integrated structure through solder. This supporting structure can greatly improve the extrusion strength of the graphene temperature-averaging plate 100; the heat is transferred from the heat-conducting boss 5 of the base plate 2 to the heat-conducting column 7 of the cover plate 1, and the heat-conducting column 7 contacts the side of the graphene interlayer to conduct the heat to the graphene interlayer, further solving the problem that the heat is difficult to conduct directly along the normal direction.

[0054] The reinforcing ribs 4 with a thickness of 2.5mm to 5mm on the upper surface of the cover plate 1 improve the strength and rigidity of the graphene heat spreader 100. It can also be understood that when the mechanical requirements do not change, the present application can make the design thickness of the cover plate 1 thinner, which is helpful for the weight reduction design of satellite payload equipment. The grooves 6 inside the reinforcing ribs 4 are filled with graphene. According to its anisotropic thermal conductivity, most of the heat can be conducted to the cover plate 1 of the heat spreader 100 through the side wall surface of the grooves 6 and the end surface of the grooves 6. On this basis, the present application designs the end surface of the grooves 6 as a transition slope 8 of 30° to 60° to increase the thermal contact area between the graphene and the cover plate 1. That is, the design of the reinforcing ribs 4 and the grooves 6 of the cover plate 1 simultaneously realizes the improvement of the normal thermal conductivity of the heat spreader 100, the improvement of the temperature equalization capability, and the improvement of the structural strength and rigidity.

[0055] The embodiment of the present application further discloses a method for preparing a temperature homogenizing plate, which is used to prepare the temperature homogenizing plate as mentioned above, comprising:

[0056] Step S110: preparing the bottom plate by machining, and setting heat-conducting bosses on the inner surface of the bottom plate, wherein the distribution positions of the heat-conducting bosses correspond to the heat-generating positions of the external components;

[0057] Step S120: Prepare the cover plate by machining, and set a plurality of reinforcing ribs in a cross-distribution on the outer surface of the cover plate; mark positions corresponding to the plurality of reinforcing ribs on the inner surface of the cover plate, and machine grooves at the positions so that the grooves are located inside the reinforcing ribs; set heat-conducting columns at the intersections of the grooves; and machine a chamfer at the edges of the grooves;

[0058] Step S130: grinding the bottom plate and the cover plate to a preset thickness; performing anodizing and / or metal plating on the surface of the bottom plate and the surface of the cover plate to form an isolation layer;

[0059] Step S140: drying, heating, and machining the graphene oxide film to obtain a graphene interlayer, and interference fitting the graphene interlayer into the inner surface of the cover plate and the groove;

[0060] Step S150: Apply solder on the inner surface edge of the cover plate and on the contact surface of the thermally conductive column and the base plate; assemble and connect the inner surface of the base plate and the inner surface of the cover plate, and fit the thermally conductive boss to the contact surface of the thermally conductive column; fill the side gap between the base plate and the cover plate with solder; and perform compression, heating and grinding on the cover plate, the graphene interlayer and the base plate to form a temperature equalizing plate.

[0061] For example, in practical applications, the above steps S110 to S150 may not be performed in order, and some steps may be processed in reverse order or simultaneously, as long as the temperature homogenizing plate of the present application can be prepared.

[0062] In practical applications, due to the need for weight reduction, structural strength and heat dissipation, the design specifications of an embodiment of the present application are 0.6mm base plate, 0.4mm cover plate and 2mm graphene interlayer (excluding the thickness of the heat conducting boss and reinforcing ribs). The core preparation steps S110 to S150 of the above-mentioned graphene temperature equalizing plate will be described in detail below using steps (1) to (5).

[0063] (1) Determine the specific position of the heat-conducting boss on the inner surface of the base plate, that is, refer to the thermal design plan of the circuit board to make the heat-conducting boss close to the high-heat consumption chip or the component with urgent heat dissipation requirements. Use machining methods (such as turning, milling, grinding, heat treatment, etc.) to prepare the base plate structure, where the surface roughness accuracy of the heat-conducting boss is required to reach Ra1.6.

[0064] (2) Machine the cover structure of the temperature-averaging plate. In order to reserve the thickness of the reinforcing ribs and the processing allowance of the material surface, the selected pre-processed aluminum material thickness should be greater than 3.5 mm, and the preferred thickness is 4.5 mm to 6 mm. The outer surface of the cover is machined to form a cross-distributed reinforcing rib structure. The preferred thickness of the reinforcing ribs is 3 mm to 4 mm and should be less than 1 mm less than the thickness of the pre-processed aluminum material. Subsequently, the positions corresponding to the reinforcing ribs are found on the inner surface of the cover and marked with lines. The grooves are machined so that their depth is less than the thickness of the reinforcing ribs by 0.5 mm to 1.5 mm. Thermal conductive columns are formed at the intersection of the grooves, wherein the surface roughness accuracy of the thermal conductive columns is required to reach Ra1.6. The groove edges are machined using a turning tool or a rotating tool holder to form a groove bevel to increase the contact area between the graphene and the cover, thereby enhancing the normal thermal conductivity of the graphene temperature-averaging plate, wherein the optimal design angle of the groove bevel is 40° to 50°. Finally, the cover plate and the bottom plate are placed on a machining grinder and ground to the designed thickness. The conventional design thickness of the temperature-averaging plate cover plate and the bottom plate is 0.4mm to 1mm (excluding the thickness of the thermal boss and the reinforcing ribs), and the preferred thickness is 0.5mm to 0.7mm.

[0065] (3) To prevent the space payload equipment from being interfered by electromagnetic signals, surface treatment is performed on all inner and outer surfaces of the cover and base plate, mainly including two methods: anodizing and metal plating. Among them, the anodizing method is to form an oxide film with a thickness of 5μm to 15μm on the surface of the aluminum alloy structure under the action of an external current; among them, the metal plating method is to use an electromagnetic shielding coating containing metal particles on the surface of the structure, such as a silver coating or a nickel coating, and the optimal coating thickness is 8μm to 15μm.

[0066] (4) Take a graphene oxide film with a specification of 260mm*200mm*15mm, place it in a drying furnace at 110℃ to 130℃ for 1h (hour) to remove moisture, place the dried graphene film in a high-temperature furnace at 800℃ to 1200℃ for carbonization treatment for 3h, then increase the temperature to 2800℃ and maintain it for more than 10h, and finally obtain a substrate structure of a graphene interlayer. The graphene interlayer substrate obtained above is processed by machine tool grinding or laser cutting to make it interference fit in the inner surface of the temperature equalizing plate cover and the inner surface groove. The thickness of the final graphene interlayer is usually 1.5mm to 4mm (excluding the thickness of the graphene in the groove part).

[0067] (5) Place the inner surface of the heat spreader cover with the graphene interlayer facing upward on a horizontal platform, and evenly apply 5μm to 8μm thick solder on the edge of the inner surface of the cover and the contact surface between each heat-conducting column and the bottom plate. Commonly used solders include tin-bismuth alloy solder, copper-tin alloy solder, and copper-manganese-nickel alloy solder. Assemble and dock the inner surface of the bottom plate with the inner surface of the cover. This process should ensure that the contact surface of the heat-conducting boss and the heat-conducting column are completely in contact. Fill the side gap formed by the bottom plate and the cover of the assembly with solder, and use a clamping clamp to apply prestress to the outer surfaces of the cover and the bottom plate to prevent thermal expansion during the heating process. Subsequently, place it in a heating furnace at 150°C to 200°C and heat it for 45min (minutes) to 60min or until the side gap solder is liquid and maintained for 10min, and the welding work is completed. Cool down the workpiece, take out the weld gap, and grind the weld gap to complete the preparation of the high-performance graphene heat spreader of this application.

[0068] This application experiments with different temperature vapor chambers. Figure 8 This is a schematic diagram of the junction temperature change of the main chip of the satellite payload equipment obtained after using the temperature equalization board of the present application, refer to Figure 8 As shown in the figure, the high-performance graphene heat spreader with a size of 260mm*200mm*6mm designed and prepared by the above method is compared with the aluminum heat spreader with the same size and the traditional graphene heat spreader under the same thermal boundary to dissipate the heat of the main chip of the satellite payload equipment (heat consumption 25W). The change of the chip junction temperature is shown in the figure. Figure 8 After the device is turned on, the time for the chip junction temperature to reach a steady state is almost the same. When the high-performance graphene heat spreader of the present application is used, the temperature is stabilized at 67.6°C, which is 21.5°C and 6.1°C lower than that of the aluminum heat sink and the traditional graphene heat spreader, respectively.

[0069] Fig. 9 This is a schematic diagram of the comparison of the heat dissipation performance of characteristic positions of satellites in orbit after using the temperature homogenizing plate of the present application. Fig. 9 As shown, it can be seen that when the satellite is in orbit, the temperature changes at the characteristic position of the payload equipment installation surface within a complete orbital cycle when three types of temperature averaging plates of the same specifications are used. It can be found that the high-performance graphene temperature averaging plate of the present application combines the advantages of aluminum alloy and graphene, and its in-plane thermal conductivity is increased from 1034W / m·K of the traditional graphene temperature averaging plate to 1281W / m·K, and the normal thermal conductivity is increased from the original 237W / m·K to 318W / m·K, and the temperature averaging performance is significantly improved.

[0070] In terms of mass and structural strength, the high-performance graphene heat spreader has a significant weight reduction effect. The mass of a single heat spreader is reduced by 27%, and the weight of the entire spacecraft payload equipment is reduced by about one-sixth. Mechanical simulation verification shows that the bending strength of the high-performance graphene heat spreader proposed in this application is as high as 200MPa, and the corresponding payload equipment meets the impact and vibration test standards specified by the satellite model.

[0071] Although the above disclosure discusses some currently useful embodiments through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments, but rather, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of the present application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0072] Similarly, it should be noted that in order to simplify the description disclosed in this application and thus help understand one or more embodiments, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0073] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0074] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A temperature equalizing plate, characterized in that: It comprises a cover plate, a heat-conducting interlayer and a bottom plate, wherein the cover plate and the bottom plate together form a cavity, the heat-conducting interlayer is arranged in the cavity, the heat-conducting interlayer is a graphene interlayer, and the in-plane thermal conductivity of graphene is higher than the normal thermal conductivity; The heat-conducting interlayer comprises a first surface and a second surface opposite to each other, the first surface is connected to the inner surface of the cover plate, and the second surface is connected to the inner surface of the bottom plate; the outer surface of the cover plate is provided with a reinforcing rib protruding outward, a groove is provided in the reinforcing rib, the groove is connected to the inner surface of the cover plate, and the opening of the groove faces the heat-conducting interlayer; A protrusion is arranged on the first surface, and the protrusion is fitted with the groove; an inclined surface is arranged on the edge of the groove, and the groove is connected with the inner surface of the cover plate through the inclined surface.

2. The temperature equalizing plate according to claim 1, characterized in that: The thickness of the reinforcing rib is 2.5 mm to 5 mm, and the depth of the groove is 0.5 mm to 1.5 mm less than the thickness of the reinforcing rib, where mm represents millimeter.

3. The temperature equalizing plate according to claim 1, characterized in that: The angle between the inclined surface and the inner surface of the cover plate is an acute angle.

4. The temperature equalizing plate according to claim 1, characterized in that: The number of the reinforcing ribs is multiple, and the multiple reinforcing ribs are cross-distributed.

5. The temperature equalizing plate according to claim 4, characterized in that: A heat-conducting column facing the heat-conducting interlayer is arranged at the intersection of the grooves, and the height of the heat-conducting column is flush with the inner surface of the cover plate.

6. The temperature equalizing plate according to claim 5, characterized in that: A heat-conducting boss facing the heat-conducting column is arranged on the inner surface of the base plate, and a through hole is arranged on the heat-conducting interlayer. The heat-conducting boss, the through hole and the heat-conducting column correspond to each other one by one, and the heat-conducting boss is connected to the heat-conducting column through the through hole; the outer surface of the base plate is used to connect with the external component, and the distribution position of the heat-conducting boss corresponds to the heat generation position of the external component.

7. The temperature equalizing plate according to claim 1, characterized in that: The cover plate and / or the bottom plate are made of aluminum alloy.

8. A method for preparing a temperature equalizing plate, characterized in that: Used to prepare the temperature homogenizing plate according to any one of claims 1 to 7, comprising: A bottom plate is prepared by machining, and a heat-conducting boss is arranged on the inner surface of the bottom plate, wherein the distribution position of the heat-conducting boss corresponds to the heat-generating position of the external component; The cover plate is prepared by a machining method, and a plurality of reinforcing ribs are arranged on the outer surface of the cover plate in a cross-distributed manner; positions corresponding to the plurality of reinforcing ribs are marked on the inner surface of the cover plate, and grooves are machined at the positions so that the grooves are located inside the reinforcing ribs; heat-conducting columns are arranged at the intersections of the grooves; and a chamfer is machined at the edges of the grooves; Grinding the bottom plate and the cover plate to a preset thickness; performing anodizing and / or metal plating on the surface of the bottom plate and the surface of the cover plate to form an isolation layer; The graphene oxide film is dried, heated and machined to obtain a graphene interlayer, and the graphene interlayer is interference-fitted into the inner surface of the cover plate and the groove; Solder is applied on the inner surface edge of the cover plate and on the contact surface of the heat-conducting column and the base plate; the inner surface of the base plate and the inner surface of the cover plate are assembled and connected, and the heat-conducting boss is fitted with the contact surface of the heat-conducting column; solder is filled in the side gap between the base plate and the cover plate; the cover plate, the graphene interlayer and the base plate are pressed, heated and polished to form the temperature equalizing plate.

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