Bionic surface heat dissipation device

Abstract

The invention relates to the technical field of electronic device cooling, and provides a bionic surface heat dissipation device. The bionic surface heat dissipation device comprises a base body, the base body is provided with a heat dissipation face and a cavity formed in the base body, a plurality of liquid drainage holes are formed in the heat dissipation face, and the liquid drainage holes are communicated with the cavity; the heat dissipation medium is accommodated in the cavity; the heat dissipation piece is provided with a first end and a second end which are opposite to each other, the second end is connected to the heat dissipation surface, and a porous capillary structure extending from the second end to the first end is arranged in the heat dissipation piece; wherein the porous capillary structure is communicated with the liquid discharge hole, and the heat dissipation medium in the cavity can be discharged to the surface of the heat dissipation piece from the porous capillary structure under the action of capillary force. The heat dissipation device provided by the embodiment of the invention imitates a human skin heat dissipation principle, endows the base body with a function of adjusting the heat dissipation capability, can adjust the heat dissipation capability along with the change of working conditions, and meets the heat dissipation requirements of electronic devices under variable working conditions of ships.

Description

Technical Field

[0001] The invention relates to the technical field of electronic device cooling, and in particular to a bionic surface heat dissipation device. Background Art

[0002] Conventional heat dissipation methods for electronic devices are to use surface fins and air cooling. However, as the power of electronic devices increases and the size decreases, the power density increases significantly, and the demand for heat exchange technology also increases. The traditional means of increasing the heat dissipation capacity of heat dissipation devices is to increase the heat dissipation area by adding fins or heat dissipation spikes to improve the heat dissipation capacity.

[0003] However, in the field of ships, there are variable operating conditions, especially extreme operating conditions, which are prone to thermal shock, which has a great impact on electronic devices, and in severe cases, directly leads to the failure of electronic devices. Therefore, the existing heat dissipation devices cannot meet the heat dissipation needs of electronic devices under variable operating conditions. However, extreme operating conditions account for a relatively small proportion of the entire operating time. If the heat dissipation device is designed based on extreme operating conditions, the heat dissipation device will be large in size and not suitable for ships with limited space. Therefore, there is an urgent need for an adaptive heat dissipation technology that can take into account both the requirements of small size and strong heat dissipation capacity. Summary of the invention

[0004] The invention provides a bionic surface heat dissipation device, which is used to solve the problem that the heat dissipation device of electronic devices in the prior art cannot meet the heat dissipation demand under variable working conditions of ships.

[0005] The present invention provides a bionic surface heat dissipation device, comprising: A substrate, the substrate having a heat dissipation surface and a cavity arranged inside the substrate, the heat dissipation surface is provided with a plurality of drainage holes, and the drainage holes are connected to the cavity; a heat dissipation medium, the heat dissipation medium being contained in the cavity; A heat sink, the heat sink having a first end and a second end opposite to each other, the second end being connected to the heat dissipation surface, and the heat sink having a porous capillary structure extending from the second end to the first end; Wherein, the porous capillary structure is communicated with the drainage hole, and the heat dissipation medium in the cavity can be discharged from the porous capillary structure to the surface of the heat dissipation element under the action of capillary force.

[0006] According to a bionic surface heat dissipation device provided by the present invention, the pore diameter of the porous capillary structure gradually increases from the second end to the first end.

[0007] According to a bionic surface heat dissipation device provided by the present invention, the porosity of the first end is the porosity under a set permeability, and the porosity of the second end is the porosity under a set capillary force.

[0008] According to a bionic surface heat dissipation device provided by the present invention, the porosity distribution of the heat dissipation element from the first end to the second end is: =-( - ) / h×L + ; in, is the porosity of the first end, is the porosity of the second end, L is the distance between any position between the first end and the second end and the second end, is the porosity of the heat sink at a distance L from the second end, and h is the distance between the first end and the second end.

[0009] According to a bionic surface heat dissipation device provided by the present invention, the porous capillary structure is a three-periodic minimal surface structure.

[0010] According to a bionic surface heat dissipation device provided by the present invention, the heat dissipation element is a heat dissipation nail column, and the plurality of drainage holes are arranged in a one-to-one correspondence with the plurality of heat dissipation nail columns.

[0011] According to a bionic surface heat dissipation device provided by the present invention, the heat dissipation element is a heat dissipation fin, and the porous capillary structure in the heat dissipation fin is arranged corresponding to the plurality of drainage holes.

[0012] According to a bionic surface heat dissipation device provided by the present invention, a groove is provided on the side of the substrate opposite to the heat dissipation surface, and the groove is used for embedding a heat dissipation chip.

[0013] A bionic surface heat dissipation device according to the present invention also includes: A fluid replenishing device is communicated with the cavity and is used to replenish the heat dissipation medium into the cavity.

[0014] The present invention also provides an electronic device, comprising: a heat dissipation chip and any one of the above-mentioned bionic surface heat dissipation devices, wherein the heat dissipation chip is thermally connected to the substrate.

[0015] The bionic surface heat dissipation device provided by the present invention is provided with a cavity in a base, a heat dissipation medium in the cavity, a drainage hole connected to the cavity and a heat dissipation member corresponding to the drainage hole on the heat dissipation surface of the base, and a porous capillary structure is provided in the heat dissipation member, and the capillary force formed by the heat dissipation medium in the porous capillary structure is used to cause the heat dissipation medium in the cavity to be discharged to the surface of the heat dissipation member, thereby accelerating the dissipation of heat from the base. The heat dissipation device provided by the embodiment of the present invention imitates the heat dissipation principle of human skin. Under high heat dissipation requirements, the skin takes away heat through sweating and sweat evaporation, giving the base a function of adjusting the heat dissipation capacity, and can adjust the heat dissipation capacity as the working conditions change, thereby meeting the heat dissipation requirements of electronic devices under variable working conditions of ships, that is, taking into account the requirements of small size and strong heat dissipation capacity of the heat dissipation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of the bionic surface heat dissipation device provided by the present invention.

[0018] Figure 2 It is a schematic diagram of the internal structure of the heat sink in the bionic surface heat sink provided by the present invention.

[0019] Figure 3 It is a schematic diagram of the porous capillary structure in the bionic surface heat dissipation device provided by the present invention.

[0020] Figure 4 It is a top view of the bionic surface heat dissipation device provided by the present invention.

[0021] Reference numerals: 1. Base; 11. Heat dissipation surface; 12. Cavity; 13. Drain hole; 14. Groove; 2. Heat dissipation medium; 3. Heat dissipation element; 31. First end; 32. Second end; 33. Porous capillary structure; 34. Liquid channel; 4. Heat dissipation chip. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "first" and "second" are for the purpose of clearly describing the numbering of product components and do not represent any substantial difference. 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 direct connection, or an indirect connection through an intermediate medium, or it can be a connection between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances. In addition, the meaning of "multiple" is two or more.

[0024] Combine the following Figure 1-Figure 4 The bionic surface heat dissipation device of the present invention is described.

[0025] like Figure 1 As shown, the bionic surface heat dissipation device provided by the embodiment of the present invention includes a substrate 1, a heat dissipation medium 2 and a heat sink 3. The substrate 1 has a heat dissipation surface 11 and a cavity 12 arranged inside the substrate 1, and a plurality of drainage holes 13 are arranged on the heat dissipation surface 11, and the drainage holes 13 are connected to the cavity 12. The heat dissipation medium 2 is accommodated in the cavity 12. The heat sink 3 has a first end 31 and a second end 32 opposite to each other, and the second end 32 is connected to the heat dissipation surface 11, and the heat sink 3 has a porous capillary structure 33 extending from the second end 32 to the first end 31. Among them, the porous capillary structure 33 is connected to the drainage holes 13, and the heat dissipation medium 2 in the cavity 12 can be discharged from the porous capillary structure 33 to the surface of the heat sink 3 under the action of capillary force.

[0026] See also Figure 1 The intelligent bionic surface heat dissipation device provided in the embodiment of the present invention is used to dissipate heat for the heat dissipation chip 4 of the electronic device, and the substrate 1 is thermally connected to the heat dissipation chip 4. At least one heat dissipation element selected from the group consisting of heat dissipation fins, heat dissipation ribs, and heat dissipation spikes can be provided on the heat dissipation surface 11. The heat dissipation element 3 can be connected to the heat dissipation surface 11 by welding. The heat dissipation medium 2 adopts a safe cooling liquid, usually water. The second end 32 of the heat dissipation element 3 is arranged corresponding to the drainage hole 13, so that the drainage hole 13 is opposite to the inlet of the porous capillary structure 33, and the porous capillary structure 33 constitutes a liquid channel 34 in the heat dissipation element 3.

[0027] By setting the porous capillary structure 33 with pores of appropriate pore diameter and porosity, a capillary force can be generated at the interface between the heat dissipation medium 2 and the substrate 1. Under the action of the capillary force, the heat dissipation medium 2 enters the heat dissipation element 3 from the cavity 12, and then continues to flow from the second end 32 to the surface of the heat dissipation element 3 under the action of the capillary force in the heat dissipation element 3. The surface of the heat dissipation element 3 includes the surface of the first end 31 and the peripheral side surface connecting the first end 31 and the second end 32.

[0028] Each drain hole 13 may be provided with a heat sink 3, for example, one drain hole 13 may be provided with a heat sink 3. Of course, multiple drain holes 13 may be provided with a heat sink 3, for example, multiple drain holes 13 may be provided with a heat sink fin.

[0029] Under normal working conditions, that is, when the heat dissipation chip 4 generates less heat, the temperature of the base 1 is low, and the heat generated by the heat dissipation chip 4 is conducted to the heat dissipation surface 11 and the heat dissipation element 3 through the base 1, and the heat is dissipated through the heat dissipation surface 11 and the solid part of the heat dissipation element 3.

[0030] Under extremely high temperature conditions, that is, when the heat dissipation chip 4 generates a large amount of heat, the temperature of the substrate 1 rises rapidly and is transferred to the heat sink 3. The temperature of the solid part of the heat sink 3 rises, causing the liquid in the liquid channel 34 inside the heat sink 3 and on the surface to evaporate faster, thereby taking away the heat. At the same time, the heat dissipation principle of human skin is imitated. After the heat dissipation medium 2 reaches the surface of the heat sink 3, due to the liquid evaporation effect, a greater negative pressure is generated, driving the heat dissipation medium 2 from the cavity 12 through the porous capillary structure 33 to the surface of the heat sink 3, thereby continuously supplying surface evaporation and enhancing the surface heat dissipation capacity of the heat dissipation device.

[0031] The bionic surface heat dissipation device provided in the embodiment of the present invention is provided with a cavity 12 in the substrate 1, a heat dissipation medium 2 in the cavity 12, a drainage hole 13 connected to the cavity 12 and a heat dissipation member 3 corresponding to the drainage hole 13 on the heat dissipation surface 11 of the substrate 1, and a porous capillary structure 33 in the heat dissipation member 3. The capillary force formed by the heat dissipation medium 2 in the porous capillary structure 33 is used to cause the heat dissipation medium 2 in the cavity 12 to be discharged to the surface of the heat dissipation member 3, thereby accelerating the heat dissipation of the substrate 1. The heat dissipation device provided in the embodiment of the present invention imitates the heat dissipation principle of human skin. Under high heat dissipation requirements, the skin takes away heat through sweating and sweat evaporation, giving the substrate 1 the function of adjusting the heat dissipation capacity, and being able to adjust the heat dissipation capacity as the working conditions change, thereby meeting the heat dissipation requirements of electronic devices under variable working conditions of ships, that is, taking into account the requirements of small size and strong heat dissipation capacity of the heat dissipation device.

[0032] In the design of the porous capillary structure, two parameters need to be paid attention to, namely permeability and capillary force. The highly interconnected liquid channels 34 formed by the porous capillary structure 33 in the heat sink 3 have a dual role, which is to supply heat to the extended phase change interface and to transmit liquid-gas two-phase flow. On the one hand, for the spontaneous liquid absorption process of evaporation, a higher capillary force is required, and a smaller pore size can provide a greater capillary force. On the other hand, in the capillary driven evaporation process, the porous capillary structure 33 replenishes the heat dissipation medium 2 to the surface of the heat sink 3 through the capillary force, and at the same time, the steam escapes from the second end 32 toward the surface of the heat sink along the porous capillary structure 33. In the process of liquid-gas two-phase flow transmission from the second end 32 to the surface of the heat sink 3, a higher permeability is required, that is, a lower resistance is required. At this time, a larger pore size is conducive to the penetration transmission of the liquid.

[0033] In this regard, Figure 2 As shown, in the embodiment of the present invention, the aperture of the porous capillary structure 33 near the second end 32 of the heat sink 3 is larger than the aperture of the porous capillary structure 33 near the first end 31 of the heat sink 3. Thus, it can ensure that the capillary force is large enough to automatically absorb liquid and replenish liquid to the first end 31 of the heat sink 3, and it can also ensure that the heat dissipation medium 2 flows smoothly from the second end 32 to the first end 31 through the porous capillary structure 33.

[0034] In some optional embodiments, see Figure 2 The pore size of the porous capillary structure 33 gradually increases from the second end 32 to the first end 31. For example, the pore size of the porous capillary structure 33 increases uniformly or in a gradient from the second end 32 to the first end 31.

[0035] In order to further ensure that the capillary force is large enough to achieve automatic liquid absorption and replenish the first end 31 of the heat sink 3, it can also ensure that the heat dissipation medium 2 flows smoothly from the second end 32 to the first end 31 through the porous capillary structure 33. Considering that the liquid-gas two-phase flow in the transpiration is mainly at the first end 31 of the heat sink 3, the self-priming liquid absorption process mainly occurs at the second end 32 of the heat sink 3, and the capillary force and permeability are directly related to the porosity, therefore, in the embodiment of the present invention, the porosity of the first end 31 is the porosity under the set permeability, and the porosity of the second end 32 is the porosity under the set capillary force. The set permeability and the set capillary force can be given according to actual needs.

[0036] The porosity distribution of the heat sink 3 from the first end 31 to the second end 32 is: =-( - ) / h×L + (1)

[0037] In formula (1), is the porosity of the first end 31, is the porosity of the second end 32, L is the distance between any position between the first end 31 and the second end 32 and the second end 32, is the porosity at a distance L from the second end 32 of the heat sink 3 , and h is the distance between the first end 31 and the second end 32 .

[0038] Among them, according to Darcy's law, the relationship between permeability and porosity is: (2)

[0039] K in formula (2) is the permeability, is the average pore diameter, is the average porosity. According to formula (2), the porosity under a set permeability can be obtained.

[0040] The relationship between capillary force and porosity is: (3)

[0041] In formula (3), is the permeability, is the dynamic viscosity of the heat dissipation medium 2, is the porosity, K is the permeability, h is the length from the first end 31 to the second end 32 of the heat sink 3, and dh / dt is the capillary rise velocity, which can be given according to requirements. According to formula (3), the porosity under the set capillary force can be obtained.

[0042] In the embodiment of the present invention, the heat generated by the heat dissipation chip 4 is transferred to the substrate 1, and the substrate 1 is transferred to the solid part of the heat sink 3, and then transferred to the heat dissipation medium 2 through the channel inside the heat sink 3, so that the heat dissipation medium 2 evaporates and takes away the heat. In this process, in order to improve the heat dissipation capacity of the heat sink 3, it is necessary to greatly increase the heat exchange area of ​​the channel inside the heat sink 3. However, for traditional porous media, increasing the heat exchange area increases the flow resistance of the liquid, which affects the transpiration effect.

[0043] In this regard, Figure 3 As shown, in the embodiment of the present invention, the porous capillary structure is set as a three-periodic minimal surface structure, and the implicit function mathematical expression of the structure is: + + -C (4)

[0044] In formula (4), = represents the structural parameter that controls the shape of the channel space in the heat sink 3. C represents the gap parameter that controls the overall gap size of the heat sink 3. The corresponding porosity under different gap parameters is calculated. , we get the relationship between porosity and void parameter C=f( ).

[0045] The initial model of the heat sink 3 is constructed based on the above implicit function mathematical expression, the selected structural parameters and the gap parameters. In the initial model, the minimum curvature of any curved surface is zero, and there is no flow turning point, so that the resistance of the fluid flowing inside is small. Moreover, the specific surface area in the initial model is large, which can greatly increase the heat exchange area, significantly improve the heat dissipation efficiency of the heat sink 3, and reduce the resistance of the upward flow of the liquid.

[0046] In some optional embodiments, the heat sink 3 may also be a heat sink fin, and the porous capillary structure 33 in the heat sink fin is arranged corresponding to the plurality of drainage holes 13 .

[0047] like Figure 4 As shown, in some optional embodiments, the heat sink 3 is a heat sink nail column, and the plurality of drainage holes 13 are arranged one by one with the plurality of heat sink nail columns. The heat sink nail column can increase the heat dissipation area of ​​the heat sink, and can disturb the airflow passing through the heat sink, increase the contact area and contact time between the air and the surface of the heat sink, thereby improving the heat dissipation efficiency. Under the same volume, the heat sink nail column has a stronger heat dissipation capacity than the heat sink fins.

[0048] In fact, different heat sinks 3 can be arranged on the heat dissipation surface 11 according to the different heat dissipation in different areas of the electronic device, that is, different heat sinks 3 can be arranged in different areas of the heat dissipation surface 11. For example, heat dissipation ribs can be arranged in areas with lower heat dissipation, and heat dissipation spikes can be arranged in areas with higher heat dissipation, so that the heat dissipation of the entire electronic device can be more uniform and thermal stress can be reduced.

[0049] On the basis of the above embodiment, a groove 14 is provided on the side of the substrate 1 opposite to the heat dissipation surface 11, and the groove 14 is used to embed the heat dissipation chip 4. By embedding the heat dissipation chip 4 in the groove 14 of the substrate 1, the contact area between the heat dissipation chip 4 and the substrate 1 can be increased, thereby improving the heat dissipation efficiency.

[0050] On the basis of the above-mentioned embodiment, the intelligent bionic surface heat dissipation device provided in the embodiment of the present invention further includes a liquid replenishing device (not shown in the figure), which is connected to the cavity 12 and is used to replenish the heat dissipation medium into the cavity 12. Specifically, the base 1 is provided with a liquid inlet, which is connected to the liquid replenishing device through a pipeline, and the heat dissipation medium 2 can be replenished to the cavity 12 in time through the liquid replenishing device to ensure the normal function of the heat dissipation device.

[0051] The embodiment of the present invention further provides an electronic device. The electronic device includes a heat dissipation chip 4 and the intelligent bionic surface heat dissipation device described in any of the above embodiments, and the heat dissipation chip 4 is thermally connected to the substrate 1. The heat dissipation chip 4 can be thermally connected to the substrate 1 by being embedded in the groove 14 of the substrate 1, and the heat dissipation chip 4 can also be thermally connected to the substrate 1 by means of thermal conductive glue, thermal conductive pads, welding or clamping, etc., which is not specifically limited in this embodiment.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bionic surface heat dissipation device, characterized in that: include: A substrate, the substrate having a heat dissipation surface and a cavity arranged inside the substrate, the heat dissipation surface is provided with a plurality of drainage holes, and the drainage holes are connected to the cavity; a heat dissipation medium, the heat dissipation medium being contained in the cavity; A heat sink, the heat sink having a first end and a second end opposite to each other, the second end being connected to the heat dissipation surface, and the heat sink having a porous capillary structure extending from the second end to the first end; Wherein, the porous capillary structure is communicated with the drainage hole, and the heat dissipation medium in the cavity can be discharged from the porous capillary structure to the surface of the heat dissipation element under the action of capillary force.

2. The bionic surface heat dissipation device according to claim 1, characterized in that: The pore diameter of the porous capillary structure gradually increases from the second end to the first end.

3. The bionic surface heat dissipation device according to claim 2, characterized in that: The porosity of the first end is the porosity at a set permeability, and the porosity of the second end is the porosity at a set capillary force.

4. The bionic surface heat dissipation device according to claim 3, characterized in that: The porosity distribution of the heat sink from the first end to the second end is: =-( - ) / h×L + ; in, is the porosity of the first end, is the porosity of the second end, L is the distance between any position between the first end and the second end and the second end, is the porosity of the heat sink at a distance L from the second end, and h is the distance between the first end and the second end.

5. The bionic surface heat dissipation device according to claim 1, characterized in that: The porous capillary structure is a three-periodic minimal surface structure.

6. The bionic surface heat dissipation device according to claim 1, characterized in that: The heat sink is a heat sink nail column, and the plurality of drainage holes are arranged in one-to-one correspondence with the plurality of heat sink nail columns.

7. The bionic surface heat dissipation device according to claim 1, characterized in that: The heat sink is a heat sink fin, and the porous capillary structure in the heat sink fin is arranged corresponding to the plurality of drainage holes.

8. The bionic surface heat dissipation device according to claim 1, characterized in that: A groove is provided on the side of the base body opposite to the heat dissipation surface, and the groove is used for embedding a heat dissipation chip.

9. The bionic surface heat dissipation device according to claim 1, characterized in that: Also includes: A fluid replenishing device is communicated with the cavity and is used to replenish the heat dissipation medium into the cavity.

10. An electronic device, characterized in that: include: A heat dissipation chip and a bionic surface heat dissipation device as described in any one of claims 1 to 9, wherein the heat dissipation chip is thermally connected to the substrate.

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