WO2021203826A1

WO2021203826A1 - Heat dissipation apparatus and method for manufacturing same, and electronic device

Info

Publication number: WO2021203826A1
Application number: PCT/CN2021/075525
Authority: WO
Inventors: 杨鑫
Original assignee: Oppo广东移动通信有限公司
Priority date: 2020-04-08
Filing date: 2021-02-05
Publication date: 2021-10-14
Also published as: CN111447793A; CN111447793B

Abstract

The present application provides a heat dissipation apparatus, comprising a first cover plate, a second cover plate, a capillary core, and a working fluid. The first cover plate and the second cover plate are combined to form a closed accommodating space; the capillary core is provided on the surface of the first cover plate close to the accommodating space; the working fluid is filled in the accommodating space; the capillary core comprises a support layer and a capillary structure layer; the support layer comprises a plurality of support strips, and a plurality of hollow regions formed by arranging the plurality of support strips in a staggered manner; the capillary structure layer is provided between the support layer and the first cover plate; the capillary structure layer comprises a plurality of microstructures arranged on the support strips at intervals; and the size of a gap between adjacent microstructures is smaller than the transverse size of the hollow regions. The hollow regions do not generate a capillary force to the working fluid, thereby preventing a liquid-state working fluid in the capillary core from interacting with a gas-state working fluid in the accommodating space, implementing gas-liquid separation, and improving the heat dissipation performance of the heat dissipation apparatus.

Description

Heat dissipation device, preparation method of heat dissipation device, and electronic equipment

Technical field

This application belongs to the field of heat conduction technology, and specifically relates to a heat dissipation device, a preparation method of the heat dissipation device, and electronic equipment.

Background technique

When electronic equipment is in operation, heat is generated, which directly causes the temperature of the electronic equipment to rise sharply. Therefore, a heat sink must be used to quickly dissipate the heat. Take the soaking plate as an example, it uses the phase change of the working fluid to transfer heat to complete the heat dissipation; but in this process, the gaseous working fluid in the vapor chamber interacts with the liquid working fluid in the capillary structure, which causes the flow of each other Interference, thereby reducing the heat transfer speed, affecting the heat dissipation effect, and even losing the heat dissipation effect.

Summary of the invention

In view of this, the present application provides a heat dissipation device and a method for preparing the heat dissipation device, which is beneficial to gas-liquid separation, effectively avoids the interaction of working fluids between different forms, improves the heat dissipation performance of the heat dissipation device, and realizes efficient heat dissipation; at the same time, it also provides The electronic equipment of the heat dissipation device improves the heat dissipation performance of the electronic equipment, facilitates the heat dissipation of the electronic equipment, and ensures the performance of the electronic equipment.

In a first aspect, the present application provides a heat dissipation device, including a first cover plate, a second cover plate, a capillary wick, and a working fluid. The first cover plate and the second cover plate cover together to form a sealed container The capillary wick is arranged on the surface of the first cover plate close to the accommodating space, and the working fluid is filled in the accommodating space, wherein the capillary wick includes a support layer and a capillary structure layer, The supporting layer includes a plurality of supporting bars and a plurality of hollow areas formed by staggered arrangement of the supporting bars, the capillary structure layer is disposed between the supporting layer and the first cover plate, and the The capillary structure layer includes a plurality of microstructures arranged on the support bar at intervals, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area.

In the second aspect, the present application provides a method for manufacturing a heat sink, including:

A capillary core is provided, the capillary core includes a support layer and a capillary structure layer, the support layer includes a plurality of support bars and a plurality of hollow areas formed by staggered arrangement of the plurality of support bars, the capillary structure layer includes a plurality of Two microstructures spaced apart on the support bar, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area;

A first cover plate and a second cover plate are provided, and the first cover plate and the second cover plate are combined to form a closed accommodating space, the capillary core is arranged in the accommodating space, and the capillary The structural layer is arranged between the support layer and the first cover plate;

A working fluid is injected into the accommodating space, and a heat dissipation device is formed after sealing.

In a third aspect, the present application provides an electronic device including a heating element and a heat dissipation device. The heat dissipation device includes a first cover plate, a second cover plate, a capillary core, and a working fluid. The first cover plate and the heat dissipation device The second cover plate is covered to form a closed accommodating space, the capillary wick is disposed on the surface of the first cover plate close to the accommodating space, and the working fluid is filled in the accommodating space, wherein The capillary core includes a support layer and a capillary structure layer. The support layer includes a plurality of support bars and a plurality of hollow areas formed by staggered arrangement of the plurality of support bars. The capillary structure layer is arranged on the support layer and Between the first cover plates, the capillary structure layer includes a plurality of microstructures arranged on the support bar at intervals, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area, and The heat dissipation device is arranged corresponding to the heating element.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the drawings that need to be used in the embodiments of the present application will be described below.

FIG. 1 is a cross-sectional view of a heat dissipation device provided by an embodiment of the application.

Fig. 2 is a top view of a support layer provided by an embodiment of the application.

Fig. 3 is a partial enlarged view of a supporting layer provided by an embodiment of the application.

Fig. 4 is a partial enlarged view of a supporting layer provided by another embodiment of the application.

Fig. 5 is a schematic diagram of a capillary structure layer provided by an embodiment of the application.

Fig. 6 is a partial enlarged view of the capillary structure layer of Fig. 5.

Fig. 7 is a top view of a capillary wick provided by an embodiment of the application.

Fig. 8 is a partial enlarged view of the capillary wick of Fig. 7.

FIG. 9 is a schematic flowchart of a method for manufacturing a heat sink provided by an embodiment of the application.

FIG. 10 is a schematic structural diagram of an electronic device provided by an embodiment of this application.

FIG. 11 is a schematic cross-sectional view of an electronic device provided by another embodiment of this application.

Label description:

The first cover plate-10, the second cover plate-20, the capillary core-30, the supporting layer-31, the supporting bar-310, the first supporting bar-3101, the second supporting bar-3102, the third supporting bar-3103, Hollow area-311, capillary structure layer-32, microstructure-320, first microstructure-321, second microstructure-322, frame-33, accommodating space-40, support structure-50, heat dissipation device-100, Heating element-200, panel-300, shell-400, middle plate-500.

Detailed ways

The following are the preferred embodiments of this application. It should be noted that for those of ordinary skill in the art, without departing from the principles of this application, several improvements and modifications can be made, and these improvements and modifications are also regarded as the original The scope of protection applied for.

The following disclosure provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and are not intended to limit the application. In addition, the present application may repeat reference numerals and/or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and/or settings discussed. In addition, this application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and/or the use of other materials.

The embodiment of the present application provides a heat dissipation device, which includes a first cover plate, a second cover plate, a capillary core, and a working fluid. The first cover plate and the second cover plate cover together to form a closed accommodating space, The capillary wick is arranged on the surface of the first cover plate close to the accommodating space, and the working fluid is filled in the accommodating space. The capillary wick includes a support layer and a capillary structure layer. The support layer includes a plurality of support bars and a plurality of hollow areas formed by staggered arrangement of the plurality of support bars, the capillary structure layer is arranged between the support layer and the first cover plate, and the capillary structure The layer includes a plurality of microstructures arranged on the support bar at intervals, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area.

Wherein, a plurality of the microstructures are arranged in an array on the capillary structure layer.

Wherein, the microstructure includes a first microstructure and a second microstructure, the length extension directions of the first microstructure and the second microstructure are staggered, and the first microstructure and the second microstructure are spaced apart from each other. set up.

Wherein, the plurality of support bars includes a plurality of first support bars arranged in parallel and a plurality of second support bars arranged in parallel, and a plurality of the first support bars and a plurality of the second support bars are arranged in a staggered manner. The cloth forms the hollow area.

Wherein, the first supporting bar and the second supporting bar intersect to form a supporting node, and the microstructure is arranged on the supporting node.

Wherein, the lateral size of the microstructure is 5 μm-60 μm, the thickness is 5 μm-40 μm, and the gap between adjacent microstructures is 5 μm-50 μm.

Wherein, the thickness of the support layer is 5 μm-40 μm, and the lateral dimension of the hollow area is 40 μm-150 μm.

Wherein, the material of the capillary core includes at least one of copper, titanium, nickel and tin or stainless steel.

Wherein, the capillary core is an integrally formed structure.

Wherein, the opening areas of the plurality of hollow areas are the same.

Wherein, the distance between the support layer and the second cover plate is 20 μm-120 μm.

Wherein, the shape of the microstructure includes at least one of a cube, a rectangular parallelepiped, a cylinder, and an irregular three-dimensional structure.

Wherein, the capillary core further includes a frame, and the frame surrounds the periphery of the support layer and the capillary structure layer.

Wherein, the heat dissipation device further includes a supporting structure, the supporting structure is arranged in the accommodating space and abuts against the first cover plate and the second cover plate.

Wherein, the supporting structure abuts against the supporting layer.

The embodiment of the present application also provides a method for manufacturing a heat dissipation device, including:

Wherein, said providing capillary wick includes:

Providing a substrate, the substrate having a first surface and a second surface that are opposed to each other;

Providing a first mask, and performing glue coating, exposure, development and etching treatments on the first surface of the substrate to form the support layer;

A second mask is provided, and the second surface of the substrate is coated with glue, exposed, developed and etched to form the capillary structure layer to obtain the capillary core.

Wherein, the exposure accuracy is 0.5 μm-5 μm, and the etching accuracy is 0.5 μm-5 μm.

The embodiment of the present application also provides an electronic device, including a heating element and a heat dissipation device. The heat dissipation device includes a first cover plate, a second cover plate, a capillary core, and a working fluid. The first cover plate and the second cover plate The two cover plates are combined to form a closed accommodating space, the capillary wick is arranged on the surface of the first cover plate close to the accommodating space, and the working fluid is filled in the accommodating space, wherein the The capillary core includes a support layer and a capillary structure layer. The support layer includes a plurality of support bars and a plurality of hollow areas formed by staggered arrangement of the plurality of support bars. The capillary structure layer is disposed on the support layer and the capillary structure layer. Between the first cover plates, the capillary structure layer includes a plurality of microstructures spaced apart on the support bar, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area, and the heat dissipation The device is arranged corresponding to the heating element.

Wherein, the electronic equipment further includes a middle plate, and the heat dissipation device is embedded in the middle plate and is arranged in close contact with the heating element.

Please refer to FIG. 1, which is a cross-sectional view of a heat dissipation device 100 according to an embodiment of the application. The heat dissipation device 100 includes a first cover plate 10, a second cover plate 20, a capillary core 30 and a working fluid. The first cover plate 10 and the second cover plate The cover plate 20 is covered to form a closed accommodating space 40, the capillary wick 30 is arranged on the surface of the first cover plate 10 close to the accommodating space 40, and a working fluid (not shown in the figure) is filled in the accommodating space 40, wherein The capillary core 30 includes a support layer 31 and a capillary structure layer 32. The support layer 31 includes a plurality of support bars 310 and a plurality of hollow areas 311 formed by staggered arrangement of the plurality of support bars 310. The capillary structure layer 32 is disposed on the support layer 31. Between the capillary structure layer 32 and the first cover plate 10, the capillary structure layer 32 includes a plurality of microstructures 320 arranged on the support bar 310 at intervals, and the gap between adjacent microstructures 320 is smaller than the lateral dimension of the hollow area 311.

In the present application, when the first cover plate 10 of the heat sink 100 is in contact with the heat source, it absorbs heat and is transferred to the liquid working fluid in the capillary core 30. The liquid working fluid absorbs the heat and vaporizes to form a gaseous working fluid, which passes through the heat sink 100 The accommodating space 40, which can also be referred to as a steam chamber, transfers heat from the first cover plate 10 to the second cover plate 20, and transfers the heat to the outside through the second cover plate 20. During the heat transfer process, the gaseous working fluid is condensed into a liquid working fluid, and the capillary force generated by the capillary core 30 drains it to the first cover plate 10, and the heat dissipation process described above is cyclically performed to complete the heat dissipation. The heat dissipation device 100 provided in the present application transfers heat through the phase change of the working fluid, and the heat dissipation device 100 may be, but is not limited to, a soaking plate.

In the related art, the capillary wick only has a capillary structure layer. After the liquid working fluid in the capillary structure layer is heated and evaporated, it forms a gaseous working fluid and enters the accommodating space; due to the capillary force of the capillary structure layer, and the accommodating space The interaction force between the gaseous working fluid and the liquid working fluid in the capillary structure layer causes the gaseous working fluid to be affected by the force when it diffuses, and thus cannot fill the containing space, which affects the heat dissipation volume and heat dissipation speed, and makes the entire heat dissipation device Reduced heat dissipation effect may even lose heat dissipation performance; what's more, after reducing the thickness of the heat dissipation device, the interaction force becomes more obvious, and the gaseous working fluid suffers greater resistance during diffusion, which further reduces the heat dissipation volume and heat dissipation speed. In this application, the capillary core 30 is provided with a support layer 31 and a capillary structure layer 32, wherein the gap between adjacent microstructures 320 in the capillary structure layer 32 is smaller than the lateral size of the hollow area 311 in the support layer 31, so that The capillary structure layer 32 generates capillary force, while the support layer 31 does not generate capillary force. Therefore, during the heat dissipation process, when the liquid working fluid in the capillary structure layer 32 is heated to become a gaseous working fluid, it enters the accommodating space 40 through the hollow area 311 of the support layer 31, and then flows in the direction of the second cover plate 20, Realize the heat transfer; in this process, the hollow area 311 of the support layer 31 does not produce capillary force on the gaseous working fluid, and will not affect the flow of the gaseous working fluid, so that the gaseous working fluid can quickly enter the accommodating space 40 and proceed. Large area diffusion increases the heat dissipation volume and heat dissipation speed. That is to say, the heat dissipation device 100 provided by the present application is provided with the supporting layer 31 to separate the interaction force between the gaseous working fluid in the accommodating space 40 and the liquid working fluid in the capillary structure layer 32, thereby helping to improve heat dissipation. At the same time, after reducing the thickness of the heat sink 100, the gaseous working fluid in the accommodating space 40 and the liquid working fluid in the capillary structure layer 32 will not interact with each other, ensuring the heat dissipation speed and heat dissipation volume, so , The heat dissipation device 100 provided in the present application can also be light and thin, which is beneficial to its application.

In the present application, the support layer 31 supports the capillary structure layer 32, and the hollow area 311 can be used as a channel for the working fluid to flow in the heat dissipation cycle. The supporting layer 31 includes a plurality of supporting bars 310 and a plurality of hollow areas 311 formed by the plurality of supporting bars 310 staggered, that is, the plurality of supporting bars 310 are staggered to form the supporting layer 31 with a grid structure. Please refer to FIG. 2, which is a top view of the support layer 31 provided by an embodiment of the present application. The support layer 31 includes a plurality of support bars 310 and a plurality of hollow areas 311 formed by staggered arrangement of the plurality of support bars 310.

Please refer to FIG. 3, which is a partial enlarged view of the support layer provided by an embodiment of the application, wherein the plurality of support bars 310 includes a plurality of first support bars 3101 arranged in parallel and a plurality of second support bars 3102 arranged in parallel , The plurality of first supporting bars 3101 and the plurality of second supporting bars 3102 are arranged in a staggered manner to form a plurality of hollow areas 311. Please refer to FIG. 4, which is a partial enlarged view of the support layer provided by another embodiment of this application. The plurality of support bars 310 includes a plurality of first support bars 3101 arranged in parallel, and a plurality of second support bars 3102 arranged in parallel. And a plurality of third support bars 3103 arranged in parallel, a plurality of first support bars 3101, a plurality of second support bars 3102, and a plurality of third support bars 3103 are alternately arranged to form a plurality of hollow areas 311. In another embodiment of the present application, the plurality of support strips 310 may have different extension directions and arrangements, and are arranged irregularly, forming a hollow area 311 staggered. In this application, the length and width of the support bar 310 can be selected according to the needs of the heat sink 100. For example, the length of the support bar 310 can be but not limited to 50mm-1000mm, and the width can be but not limited to 20μm-200μm. In the present application, the support layer 31 includes a plurality of support bars 310, and the number of the support bars 310 can be selected according to the performance of the heat dissipation device 100. For example, the number of the support bars 310 in the support layer 31 can be, but is not limited to, more than 50, 100, 150, 200, etc.

In the present application, a plurality of support bars 310 are staggered to form a plurality of hollow areas 311. The cross-section of the hollow areas 311 can be, but not limited to, a square, a rectangle, a diamond, a trapezoid, an irregular shape, and the like. In an embodiment of the present application, the plurality of hollow areas 311 are regularly arranged on the support layer 31, so that the gaseous working fluid passes through the hollow areas 311 at the same speed during the heat dissipation process, thereby ensuring a stable heat dissipation effect. In another embodiment of the present application, the opening areas of the plurality of hollow areas 311 are the same, so that the amount of gaseous working fluid passing through the hollow areas 311 during the heat dissipation process is the same, thereby ensuring a stable heat dissipation effect. In another embodiment of the present application, the first cover plate 10 includes a first area and a second area adjacent to the first area. During the application process, the first area can be set corresponding to the heating element. The opening area of the hollow area 311 corresponding to the first area in the support layer 31 is larger than the opening area of the hollow area 311 corresponding to the second area, so that the gaseous working fluid can enter the accommodating space 40 through the hollow area 311 in a large amount and quickly. Thereby, heat is transferred to the second cover plate 20, and the heat dissipation speed of the heat dissipation device 100 is improved. It can be understood that the hollow area 311 has a length, a width, and a depth, and the lateral size of the hollow area 311 refers to the size of the hollow area 311 in the length direction. In one embodiment of the present application, the lateral dimension of the hollow area 311 is 40 μm-150 μm, 45 μm-150 μm, 50 μm-140 μm, 50 μm-120 μm, or 65 μm-110 μm, so that the hollow area 311 does not have a capillary effect on the working fluid, and thus does not Affect the flow of working fluid. Specifically, the lateral size of the hollow area 311 may be, but is not limited to, 40 μm, 55 μm, 70 μm, 85 μm, 95 μm, 110 μm, 125 μm, or 145 μm. In this application, the number of hollow areas 311 can be selected according to actual needs. For example, the number of hollow areas 311 in the support layer 31 is greater than 1000, 1800, 2500, 5000, etc.

In the present application, the material of the support layer 31 can be, but is not limited to, at least one of copper, titanium, nickel, and tin or stainless steel, so that the support layer 31 can conduct heat and at the same time facilitate the working fluid to transfer heat. In one embodiment, the material of the support layer 31 is copper, copper-titanium alloy or stainless steel, so that the support layer 31 has better mechanical properties. In one embodiment of the present application, the thickness of the support layer 31 is 5 μm-40 μm, which further reduces the interaction between working fluids of different forms; if the thickness is too small, the capillary structure layer 32 and the accommodating space 40 work in different forms The fluids are more likely to interact with each other and affect the heat dissipation effect; if the thickness is too large, the thickness and weight of the heat dissipation device 100 will increase, which is not conducive to the lightness and thinness of the heat dissipation device 100. In the present application, the lateral size of the support layer 31 can be selected according to the size of the heat dissipation device 100 and actual needs; at the same time, the cross section of the support layer 31 can be, but is not limited to, square, rectangular, diamond, round, oval, or irregular. Shape etc. In the embodiment of the present application, there is a distance between the support layer 31 and the second cover plate 20, so that the gaseous working fluid has a larger diffusion volume in the accommodating space 40, and the heat dissipation effect is improved. Further, the distance between the support layer 31 and the second cover plate 20 is 20 μm-120 μm. Furthermore, the distance between the support layer 31 and the second cover plate 20 is 40 μm-120 μm, 50 μm-115 μm, or 60 μm-100 μm, which further increases the heat dissipation volume of the gaseous working fluid inside the heat dissipation device 100.

In the present application, the capillary structure layer 32 is provided between the support layer 31 and the first cover plate 10. The capillary structure layer 32 includes a plurality of microstructures 320 arranged on the support bar 310 at intervals, and the gap between adjacent microstructures 320 The gap is smaller than the lateral dimension of the hollow area 311. Please refer to FIG. 5, which is a schematic diagram of the capillary structure layer 32 according to an embodiment of the present application. The capillary structure layer 32 includes a plurality of microstructures 320, and there are gaps between adjacent microstructures 320 to generate capillary force. In the present application, the lateral size of the microstructure 320 is 5 μm-60 μm, and the thickness is 5 μm-40 μm, so that more microstructures 320 are distributed in a certain area, thereby generating greater capillary force. Further, the lateral dimension of the microstructure 320 is 10 μm-55 μm, and the thickness is 10 μm-35 μm. Furthermore, the lateral dimension of the microstructure 320 is 10 μm-45 μm, and the thickness is 10 μm-30 μm. In an embodiment of the present application, the gap between adjacent microstructures 320 is 5 μm-50 μm, so that the capillary structure layer 32 generates a large capillary force, so that the liquid working fluid can quickly flow back into the capillary structure layer 32. The heat of the first cover plate 10 is absorbed, and the next heat dissipation cycle is performed. Further, the gap between adjacent microstructures 320 is 8 μm-45 μm. Furthermore, the gap between adjacent microstructures 320 is 10 μm-40 μm. In this application, the shape of the microstructure 320 can be, but is not limited to, a cube, a cuboid, a cylinder, an irregular three-dimensional structure, and the like. In one embodiment, the shape of the microstructure 320 is a cylinder, a cube, or a rectangular parallelepiped, so that the capillary force everywhere in the capillary structure layer 32 is more uniform. In one embodiment of the present application, a plurality of microstructures 320 are arranged in an array on the capillary structure layer 32, which is beneficial to make the capillary force in the capillary structure layer 32 more uniform, and increase the uniform heat dissipation of the heat dissipation device. And stability. Please refer to FIG. 6, which is an enlarged view of the dotted line part of the capillary structure layer 32 of FIG. 5. The microstructure 320 includes a first microstructure 321 and a second microstructure 322. The directions are staggered, and the first microstructure 321 and the second microstructure 322 are arranged at intervals, so that a gap is generated between the adjacent first microstructure 321 and the second microstructure 322, thereby generating capillary force. In one embodiment, the first microstructure 321 and the second microstructure 322 have the same shape, and the first microstructure 321 and the second microstructure 322 are arranged on the support layer 31 at intervals, so that the capillary force in the capillary structure layer 32 is uniform , Thereby improving the stability of heat dissipation.

In the present application, the material of the capillary structure layer 32 can be, but is not limited to, at least one of copper, titanium, nickel, and tin or stainless steel, so that when the capillary structure layer 32 is located between the support layer 31 and the first cover plate 10, It has good mechanical properties, is not easily deformed, and can store working fluid in the gap. In an embodiment of the present application, the first cover plate 10 includes a first area and a second area adjacent to the first area. During the application process, the first area can be set corresponding to the heating element. At this time, The thickness of the microstructure corresponding to the first region of the capillary structure layer 32 is greater than the thickness of the microstructure corresponding to the second region, so that a greater capillary force is generated in the capillary structure layer 32 corresponding to the first region to accommodate more work Fluid, thereby improving the heat dissipation performance of the heat dissipation device 100.

Please refer to FIG. 7, which is a top view of the capillary core 30 according to an embodiment of the present application. The capillary core 30 includes a support layer 31 and a capillary structure layer 32. Please refer to FIG. 8, which is an enlarged view of the dotted line part of the capillary core 30 in FIG. In the present application, the support layer 31 supports and fixes the capillary structure layer 32. In one embodiment, a plurality of supporting bars 310 are staggered to form a hollow area 311, the position where the supporting bars 310 intersect is a supporting node, and the microstructure 320 is disposed on the supporting node. In another embodiment, the plurality of support bars 310 includes a plurality of first support bars 3111 arranged in parallel and a plurality of second support bars 3112 arranged in parallel, and the first support bars 3111 and the second support bars 3112 intersect to form The supporting node, the microstructure 320 is arranged on the supporting node. In the present application, the material of the capillary core 30 can be, but is not limited to, at least one of copper, titanium, nickel, and tin or stainless steel to improve the thermal conductivity and mechanical properties of the capillary structure. In an embodiment of the present application, please refer to FIG. 7, the capillary core 30 may also include a frame 33 that surrounds the periphery of the support layer 31 and the capillary structure layer 32 to better enable the working fluid to flow in the capillary core and participate Cooling cycle.

In the present application, the capillary core 30 can be formed by, but not limited to, integral molding. In one embodiment of the present application, a substrate can be provided, and a mask plate corresponding to the required support layer 31 and capillary structure layer 32 can be prepared in advance, and glue coating, exposure, development, and development can be performed on the two opposite surfaces of the substrate. After etching, the capillary core 30 is obtained. Further, the sum of the etching depths on opposite sides of the substrate is greater than or equal to the thickness of the substrate, so that the etching is complete. Further, the exposure precision is 0.5μm-5μm, and the etching precision is 0.5μm-5μm, to form the support layer 31 with the hollow area 311 and the capillary structure layer 32 with the microstructure 320, and the formed support layer 31 and the capillary structure The thickness is controllable and small, which is conducive to reducing the thickness of the heat dissipation device 100. In the related art, the capillary structure layer is prepared by weaving a copper mesh. Due to the limitation of the diameter of the copper mesh, the thickness of the capillary structure layer cannot be reduced, so that the thickness of the heat sink cannot be further reduced, and the gaseous working fluid is also restricted. The heat dissipation volume is large, the resistance is large when the heat is dissipated, and the heat dissipation speed is slow. The capillary structure layer 32 made by the method of the present application has a controllable thickness, which can greatly reduce the thickness of the capillary structure layer 32, which is beneficial to reduce the thickness of the heat sink 100; at the same time, due to the existence of the support layer 31, it avoids The mutual interference of working fluids of different forms reduces the resistance of the working fluid during the heat dissipation process, and the thickness of the support layer 31 can be further reduced; in addition, even if the thickness of the heat dissipation device 100 is further reduced, the working fluid will still not be affected. The heat dissipation speed affects, that is, it does not affect the heat dissipation performance of the heat dissipation device 100 and is more reliable.

In the present application, the heat dissipation device 100 includes a first cover plate 10 and a second cover plate 20, and the first cover plate 10 and the second cover plate 20 cover together to form a closed accommodating space 40. It is understandable that the terms "first" and "second" in this application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Wherein, the capillary wick 30 is provided on the first cover plate 10. When in use, the surface of the first cover plate 10 away from the second cover plate 20 is attached to the heat source, including direct attachment and indirect attachment through other components. ; Of course, the capillary wick 30 can also be arranged on the second cover plate 20, at this time the second cover plate 20 is away from the surface of the first cover plate 10 and is arranged in close contact with the heat source.

In this application, in order to realize the lightness and thinness of the heat dissipation device 100, optionally, the thickness of the first cover plate 10 is less than or equal to 200 μm, and the thickness of the second cover plate 20 is less than or equal to 200 μm. Further, the thickness of the first cover plate 10 is less than or equal to 170 μm, and the thickness of the second cover plate 20 is less than or equal to 170 μm. Furthermore, the thickness of the first cover plate 10 is less than or equal to 150 μm, and the thickness of the second cover plate 20 is less than or equal to 150 μm. In the present application, the first cover plate 10 and the second cover plate 20 are composed of materials with thermal conductivity. In an embodiment, the thermal conductivity of the first cover plate 10 is greater than 10 W/(m·K), and the thermal conductivity of the second cover plate 20 is greater than 10 W/(m·K), so that the heat dissipation device 100 has an excellent heat dissipation effect . In an embodiment, the material of the first cover plate 10 includes at least one of copper, titanium, nickel and tin or stainless steel, and the material of the second cover plate 20 includes at least one of copper, titanium, nickel and tin or Stainless steel. Further, the material of the first cover plate 10 is titanium, copper-titanium alloy, copper-nickel alloy, copper-tin alloy or stainless steel, and the material of the second cover plate 20 is titanium, copper-titanium alloy, copper-nickel alloy, copper-tin alloy or stainless steel. , So that the first cover plate 10 and the second cover plate 20 have better mechanical properties, which is beneficial to reduce their thickness while ensuring the good performance of the heat dissipation device 100. It is understandable that the materials of the first cover plate 10 and the second cover plate 20 may be the same or different, and the materials of the first cover plate 10 or the second cover plate 20 and the capillary core 30 may be the same or different. In an embodiment, the first cover plate 10 and the second cover plate 20 may have a single-layer structure or a multi-layer structure, which can be specifically selected according to actual needs.

In the embodiment of the present application, the first cover plate 10 includes a first horizontal layer and a first frame arranged on the edge of the surface of the first horizontal layer. In this case, the first cover plate 10 can be manufactured by, but not limited to, integral molding. In another embodiment of the present application, the first cover plate 10 has a horizontal structure. In the embodiment of the present application, the second cover plate 20 includes a second horizontal layer and a second frame provided on the edge of the surface of the second horizontal layer. In this case, the second cover plate 20 can be, but not limited to, be made by integral molding. In another embodiment of the present application, the second cover 20 has a horizontal structure. In one embodiment, the first frame abuts against the second frame to form an accommodating space 40. In another embodiment, the first frame and the second cover plate 20 of the horizontal structure abut to form an accommodating space 40. In another embodiment, the second frame abuts against the first cover plate 10 of the horizontal structure to form the accommodating space 40. In another embodiment, the horizontal structure of the first cover plate 10 and the second cover plate 20 can be, but not limited to, forming the accommodating space 40 by welding or gluing, such as laser welding, diffusion welding, solder welding, and glue bonding. Wait.

In the present application, the accommodating space 40 is in a vacuum state, so that the working fluid can easily be vaporized and conduct heat conduction. Optionally, the vacuum degree in the accommodating space 40 is 10 ^-3 -10 ^-1 Pa. Further, the degree of vacuum in the accommodating space 40 is 10 _-2 -10 ^-1 Pa. It is understandable that the working fluid is selected from substances that do not chemically react with the first cover plate 10, the second cover plate 20, and the capillary core 30. Optionally, the working fluid is selected from water, propylene glycol, acetone or methanol. Specifically, the working fluid may be, but is not limited to, deionized water. The filling amount of the working fluid in the accommodating space 40 also affects the heat dissipation efficiency of the heat dissipation device 100. If the filling amount is too small, the heat taken away in one heat dissipation cycle is limited, and the filling amount is too much, which increases the weight of the heat dissipation device 100. Optionally, the filling amount of the working fluid in the accommodating space 40 is 15%-70%, which can effectively dissipate heat without making the heat sink 100 excessively heavy. Further, the filling amount of the working fluid in the accommodating space 40 is 30%-65%.

In this application, in order to meet the needs of light and thin heat dissipation device 100, and at the same time have strong mechanical properties, therefore, the heat dissipation device 100 further includes a support structure 50, which provides a certain support for the accommodation space 40 of the heat dissipation device 100 effect. In one embodiment, referring to FIG. 1, the heat dissipation device 100 includes at least one supporting structure 50. The supporting structure 50 is disposed in the accommodating space 40 and abuts against the first cover plate 10 and the second cover plate 20. In an embodiment, the supporting structure 50 abuts against the supporting layer 31 in the capillary core 30. In the present application, the thickness of the support structure 50 is selected according to actual needs, and can be, but is not limited to, 20 μm-120 μm. It is understandable that the support structure 50 mainly supports the heat dissipation device 100, and the selection of its material can be selected according to needs, and it can be but not limited to metal, such as copper, copper alloy, and the like.

In the present application, the heat dissipation device 100 provided in the present application is provided with a support layer 31, which separates the interaction force between the gaseous working fluid in the accommodating space 40 and the liquid working fluid in the capillary structure layer 32, thereby helping to improve Heat dissipation volume and heat dissipation speed; at the same time, after reducing the thickness of the heat dissipation device 100, there is still no interaction between the gaseous working fluid in the accommodating space 40 and the liquid working fluid in the capillary structure layer 32, ensuring the heat dissipation speed and heat dissipation volume, Therefore, the heat dissipation device 100 provided in the present application can also realize the lightness and thinness of the heat dissipation device 100. Optionally, the thickness of the heat dissipation device 100 is less than or equal to 280 μm. Further, the thickness of the heat dissipation device 100 is less than or equal to 250 μm.

The present application also provides a method for preparing a heat dissipation device, and the preparation method prepares the heat dissipation device 100 of any one of the foregoing embodiments. Please refer to FIG. 9, which is a schematic flowchart of a method for manufacturing a heat sink 100 according to an embodiment of the application, including the following steps:

Operation 101: Provide a capillary core, the capillary core includes a support layer and a capillary structure layer, the support layer includes a plurality of support bars and a plurality of hollow areas formed by staggered arrangement of the plurality of support bars, and the capillary structure layer includes a plurality of spaces arranged on the support For the microstructures on the strip, the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area.

In operation 101, the capillary core 30 may be formed by, but not limited to, integral molding. In one embodiment, providing the capillary wick 30 includes: providing a substrate, the substrate having a first surface and a second surface that are opposed to each other; providing a first mask, and applying glue, exposing, developing and engraving on the first surface of the substrate. The support layer 31 is formed by etching treatment; a second mask is provided, and the second surface of the substrate is coated, exposed, developed, and etched to form a capillary structure layer 32 to obtain a capillary core 30.

In one embodiment of the present application, the coating is to coat photoresist, and the photoresist is mainly prepared from different materials such as resin, photosensitizer, solvent, and functional additives in a certain proportion. According to the nature of photoresist, it can be divided into negative glue and positive glue. Specifically, the photoresist can be, but is not limited to, polycinnamate photoresist, polyhydrocarbon-bisazide photoresist, such as polyvinyl alcohol cinnamate, polyvinyloxyethyl cinnamate, cyclic Chemical rubber, etc. In one embodiment, the photoresist is coated on the first surface and the second surface of the substrate, but not limited to spin coating. Specifically, the photoresist can be evenly distributed to make the photoresist evenly distributed. After the photoresist is coated, it can be dried to make the photoresist into a film. Further, according to the required structure of the supporting layer 31 and the capillary structure layer 32, the first mask and the second mask are designed. Exposure is performed on the first surface and the second surface of the substrate respectively through the first mask and the second mask. Exposure methods can be divided into contact exposure, proximity exposure and projection exposure. In one embodiment, the exposure light source may be ultraviolet light, or may be a mercury lamp, a halogen lamp, or an ultraviolet laser (such as a laser with a wavelength of 255 nm or 355 nm, etc.). Afterwards, etching is performed to selectively remove areas not masked by the photoresist. Etching includes dry etching and wet etching. Dry etching may be, but not limited to, plasma etching, sputter etching, and reactive particle etching; wet etching may be, but not limited to, inorganic solution etching and organic solution etching. Further, the exposure precision is 0.5μm-5μm, and the etching precision is 0.5μm-5μm, to form the support layer 31 with the hollow area 311 and the capillary structure layer 32 with the microstructure 320, and the formed support layer 31 and the capillary structure The thickness is controllable and small, which is conducive to reducing the thickness of the heat dissipation device 100. In the present application, the sum of the etching depths on opposite sides of the substrate is greater than or equal to the thickness of the substrate to ensure complete etching and form the required support layer 31 and capillary structure layer 32.

Operation 102: Provide a first cover plate and a second cover plate, cover the first cover plate and the second cover plate to form a closed accommodating space, the capillary core is arranged in the accommodating space, and the capillary structure layer is arranged on the supporting layer and Between the first cover.

In operation 102, the first cover plate 10 and the second cover plate 20 can be made by, but not limited to, directly cut metal plates, and the metal plates can meet the requirements of the first cover plate 10 and the second cover plate 20 in the heat sink 100 The thermal conductivity and mechanical properties are sufficient. In order to realize the lightness and thinness of the heat dissipation device 100, optionally, the thickness of the first cover plate 10 is less than or equal to 200 μm, and the thickness of the second cover plate 20 is less than or equal to 200 μm. In the embodiment of the present application, the enclosed accommodating space 40 can be formed but not limited to welding or gluing. Optionally, the welding includes at least one of laser welding, diffusion welding, and solder welding. Solder welding includes low-temperature solder or high-temperature solder, and diffusion welding includes vacuum diffusion welding or gas shielded diffusion welding. The adhesive material can be, but not limited to, double epoxy-based adhesive material, silicon-based adhesive material, etc. When the heat dissipation device 100 further includes a supporting structure 50, the supporting structure 50 is disposed in the accommodating space 40 and abuts against the first cover plate 10 and the second cover plate 20.

Operation 103: Inject a working fluid into the accommodating space, and form a heat dissipation device after sealing.

In operation 103, the accommodating space 40 is in a vacuum state, so that the working fluid can easily be vaporized and conduct heat conduction. Optionally, the vacuum degree in the accommodating space 40 is 10 ^-3 -10 ^-1 Pa. In one embodiment, a liquid-filled pipe is welded into the accommodating space 40, a working fluid is injected into the accommodating space 40 through the liquid-filled pipe, and the heat sink 100 is formed after vacuuming and sealing.

The preparation method of the heat dissipation device 100 provided in the present application is simple, can be completed without using sophisticated equipment, has low preparation cost, and the prepared heat dissipation device 100 has excellent heat dissipation performance, which is beneficial to application.

The present application also provides an electronic device, including the heat dissipation device 100 of any of the foregoing embodiments. It is understandable that the electronic device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a watch, MP3, MP4, GPS navigator, a digital camera, etc., and the heat dissipation device 100 can be, but is not limited to, a heat sink.

Please refer to FIG. 10, which is a schematic structural diagram of an electronic device provided by an embodiment of this application. The electronic device includes a panel 300 and a housing 400. The panel 300 and the housing 400 form a receiving space, and the receiving space includes a heating element 200 and the above The heat dissipating device 100, wherein the heating element 200 and the heat dissipating device 100 are arranged correspondingly, can realize rapid heat dissipation and improve the heat dissipation efficiency; at the same time, the heat dissipating device 100 can appropriately reduce the thickness and also take into account excellent heat dissipation performance, thereby helping to realize the electronic equipment Thin and light. In practical applications, the heat sink 100 can directly contact the heating element 200, or contact the heating element 200 through the middle plate. At this time, the middle plate can be processed so that the heat sink 100 is embedded in the middle plate. Please refer to FIG. 11, which is a schematic cross-sectional view of an electronic device provided by another embodiment of this application. The electronic device includes a heating element 200, a heat dissipation device 100, and a middle plate 500. The heat dissipation device 100 is embedded in the middle plate 500 and attached to the heating element 200.合Settings. Taking a mobile phone as an example, if the heat dissipation device 100 is thicker, it will affect the mechanical properties of the midplane 500 of the mobile phone, thereby affecting the overall strength of the mobile phone. The heat dissipation device 100 provided in the present application can reduce its thickness without affecting the heat dissipation device 100. The heat dissipation performance of the mobile phone will not affect the overall performance of the mobile phone. At the same time, the heat dissipation device 100 provided by the present application can reduce its thickness under the premise of maintaining good heat dissipation performance without excessively increasing the weight of the mobile phone, and has good application prospects. .

The above provides a detailed introduction to the content provided by the implementation of the application. This article explains and explains the principles and implementations of the application. The above description is only used to help understand the methods and core ideas of the application; at the same time, for the field General technical personnel, based on the idea of this application, will have changes in the specific implementation and scope of application. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

A heat dissipation device, which is characterized in that it comprises a first cover plate, a second cover plate, a capillary core and a working fluid. The first cover plate and the second cover plate are combined to form a closed accommodation space, and the The capillary wick is arranged on the surface of the first cover plate close to the accommodating space, and the working fluid is filled in the accommodating space, wherein the capillary wick includes a support layer and a capillary structure layer, and the support layer The capillary structure layer is arranged between the support layer and the first cover plate, and the capillary structure layer includes: A plurality of microstructures are arranged on the support bar at intervals, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area.
The heat dissipation device of claim 1, wherein a plurality of the microstructures are arranged in an array on the capillary structure layer.
The heat dissipation device of claim 1, wherein the microstructure comprises a first microstructure and a second microstructure, and the length extension directions of the first microstructure and the second microstructure are staggered, and the The first microstructure and the second microstructure are arranged at intervals.
The heat sink according to claim 1, wherein the plurality of support bars comprise a plurality of first support bars arranged in parallel and a plurality of second support bars arranged in parallel, and a plurality of the first supports The strips and the plurality of second supporting strips are arranged alternately to form the hollow area.
The heat dissipation device according to claim 4, wherein the first supporting bar and the second supporting bar intersect to form a supporting node, and the microstructure is disposed on the supporting node.
The heat dissipation device of claim 1, wherein the lateral dimension of the microstructure is 5 μm-60 μm, the thickness is 5 μm-40 μm, and the gap between adjacent microstructures is 5 μm-50 μm.
The heat dissipation device according to claim 1, wherein the thickness of the support layer is 5 μm-40 μm, and the lateral dimension of the hollow area is 40 μm-150 μm.
The heat dissipation device of claim 1, wherein the material of the capillary core includes at least one of copper, titanium, nickel, and tin, or stainless steel.
The heat sink of claim 1, wherein the capillary core is an integrally formed structure.
5. The heat dissipation device of claim 1, wherein the opening areas of the plurality of hollow regions are the same.
The heat dissipation device of claim 1, wherein the distance between the supporting layer and the second cover plate is 20 μm-120 μm.
The heat dissipation device of claim 1, wherein the shape of the microstructure includes at least one of a cube, a rectangular parallelepiped, a cylinder, and an irregular three-dimensional structure.
The heat dissipation device of claim 1, wherein the capillary core further comprises a frame, and the frame surrounds the periphery of the support layer and the capillary structure layer.
The heat dissipation device according to claim 1, wherein the heat dissipation device further comprises a supporting structure, the supporting structure is disposed in the accommodating space and is connected to the first cover plate and the second cover The board abuts.
The heat dissipation device of claim 11, wherein the supporting structure abuts against the supporting layer.
A method for preparing a heat sink, which is characterized in that it comprises:

A capillary core is provided, the capillary core includes a support layer and a capillary structure layer, the support layer includes a plurality of support bars and a plurality of hollow areas formed by staggered arrangement of the plurality of support bars, the capillary structure layer includes a plurality of Two microstructures spaced apart on the support bar, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area;

A first cover plate and a second cover plate are provided, and the first cover plate and the second cover plate are combined to form a closed accommodating space, the capillary core is arranged in the accommodating space, and the capillary The structural layer is arranged between the support layer and the first cover plate;

A working fluid is injected into the accommodating space, and a heat dissipation device is formed after sealing.
The preparation method according to claim 16, wherein said providing a capillary core comprises:

Providing a substrate, the substrate having a first surface and a second surface that are opposed to each other;

Providing a first mask, and performing glue coating, exposure, development and etching treatments on the first surface of the substrate to form the support layer;

A second mask is provided, and the second surface of the substrate is coated, exposed, developed, and etched to form the capillary structure layer to obtain the capillary core.
The preparation method according to claim 17, wherein the exposure accuracy is 0.5 μm-5 μm, and the etching accuracy is 0.5 μm-5 μm.
An electronic device, characterized by comprising a heating element and a heat dissipation device, the heat dissipation device comprising a first cover plate, a second cover plate, a capillary core and a working fluid, the first cover plate and the second cover plate Covering to form a closed accommodating space, the capillary wick is disposed on the surface of the first cover plate close to the accommodating space, and the working fluid is filled in the accommodating space, wherein the capillary wick includes A support layer and a capillary structure layer, the support layer includes a plurality of support strips and a plurality of hollow areas formed by staggered arrangement of the plurality of support strips, the capillary structure layer is arranged on the support layer and the first Between the cover plates, the capillary structure layer includes a plurality of microstructures spaced apart on the support bar, and the gap between adjacent microstructures is smaller than the lateral dimension of the hollow area. The heating elements are correspondingly arranged.
The electronic device according to claim 19, wherein the electronic device further comprises a middle plate, and the heat dissipation device is embedded in the middle plate and is arranged in close contact with the heating element.