Wick, vapor chamber and electronic device

Abstract

The present application relates to the technical field of heat dissipation. Disclosed are a wick, a vapor chamber and an electronic device. By means of lap joint coupling of different capillary structures, the wick can integrate the advantages of the different capillary structures, for example, a first capillary structure and a third capillary structure have a stronger capillary force, so as to meet the requirement for a liquid return rate. A second capillary structure has a higher porosity, so as to meet the requirement for an evaporation rate. Therefore, the wick can achieve a design with an optimal capillary force, the minimum liquid flow resistance and the minimum vapor flow resistance, such that a vapor chamber achieves optimal performance, thereby meeting the heat dissipation requirement of an electronic device.

Description

Liquid wick, vapor chamber and electronic device

[0001] The present application claims priority to the Chinese patent application No. 202410294505.7, filed on March 12, 2024, and entitled "Liquid wick, vapor chamber and electronic device", the whole content of the above-mentioned application is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of heat dissipation technology, in particular to a liquid wick, a vapor chamber and an electronic device. BACKGROUND

[0003] The performance of electronic devices such as mobile phones and computers is becoming stronger and stronger, and the power consumption is also becoming larger and larger. In order to ensure the user's thermal experience and the temperature reliability of the electronic device, the heat dissipation requirement of the electronic device is becoming higher and higher. At present, the industry often uses a vapor chamber (VC) to solve the heat dissipation problem.

[0004] The vapor chamber is a closed cavity, and a capillary structure liquid wick and a working medium are arranged in the cavity. When the vapor chamber works, the liquid working medium near the evaporation end of the heat source absorbs heat and evaporates into a gaseous working medium, which moves to the condensation end and condenses into a liquid state, while releasing heat. Then, the liquid working medium returns to the evaporation end under the capillary action of the capillary structure liquid wick, and the process is repeated to achieve the function of transporting heat from the evaporation end to the condensation end for heat dissipation.

[0005] However, as the power consumption of the electronic device is becoming larger and larger, the heat flux density of the evaporation end increases, that is, a large amount of liquid working medium evaporates into a gaseous state in a short time, which puts higher requirements on the capillary structure of the liquid wick. Therefore, it is urgent to provide a new capillary structure of the liquid wick to ensure the heat dissipation effect of the vapor chamber on the electronic device. SUMMARY

[0006] In order to meet the heat dissipation requirement of the electronic device, the present application provides a liquid wick, a vapor chamber and an electronic device.

[0007] In a first aspect, the present application provides a liquid wick, comprising a first capillary structure, a second capillary structure and a third capillary structure; wherein the third capillary structure is stacked with the first capillary structure and the second capillary structure along a first direction, the first capillary structure and the second capillary structure are overlapped along a second direction, the first direction is perpendicular to the second direction; and the porosity of the second capillary structure is greater than the porosity of the first capillary structure and the porosity of the third capillary structure.

[0008] It can be understood that the liquid absorption core of the embodiment of the present application can be compatible with the advantages of different capillary structures through the coupling of different capillary structures. For example, the first capillary structure and the third capillary structure have strong capillary force to meet the requirement of liquid return speed. The second capillary structure has high porosity to meet the requirement of evaporation speed. In this way, the optimal capillary force, the minimum liquid flow resistance and the minimum vapor flow resistance design can be achieved, and the performance of the vapor chamber can be optimized.

[0009] The first direction can be the Z direction mentioned in the embodiment of the present application, and the second direction can be the X direction mentioned in the embodiment of the present application.

[0010] In some embodiments of the first aspect, the first capillary structure is a metal mesh structure or a sintered metal powder structure.

[0011] In this way, the first capillary structure has strong capillary force, which can improve the return speed of the liquid working medium.

[0012] In some embodiments of the first aspect, the second capillary structure is a preformed foam metal structure or formed by electrodeposition of metal.

[0013] In this way, the second capillary structure can ensure high porosity, which can improve the evaporation speed of the liquid working medium.

[0014] In some embodiments of the first aspect, the pore size inside the second capillary structure is in a bimodal distribution.

[0015] It can be understood that the pore size of the second capillary structure adopts a bimodal design, which can meet the requirements of high capillary force and high porosity at the same time. Both the return speed of the liquid working medium and the evaporation speed of the liquid working medium can be improved.

[0016] In some embodiments of the first aspect, the third capillary structure is a metal mesh structure or a sintered metal powder structure.

[0017] In this way, the third capillary structure has strong capillary force, which can improve the return speed of the liquid working medium. It can be understood that the first capillary structure and the third capillary structure can adopt the same structure, for example, both are metal mesh structures. Alternatively, the first capillary structure and the third capillary structure can adopt different structures, for example, the first capillary structure is a metal mesh structure, and the third capillary structure is a sintered metal powder structure.

[0018] In some embodiments of the first aspect, the capillary force of the first capillary structure and the capillary force of the third capillary structure are both greater than the capillary force of the second capillary structure.

[0019] As mentioned above, the wick is coupled by the lap joint of different capillary structures, which can combine the advantages of different capillary structures and help to improve the heat dissipation capacity of the vapor chamber.

[0020] In some embodiments of the first aspect, the third capillary structure has a dimension in the second direction that is greater than a dimension of the second capillary structure in the second direction.

[0021] In this way, the third capillary structure and the first capillary structure jointly assist the return flow of the liquid working medium, and reduce the dryout of the second capillary structure.

[0022] In some embodiments of the first aspect, the thickness of the wick along the first direction is equal to the sum of the thicknesses of the first capillary structure or the second capillary structure and the third capillary structure along the first direction.

[0023] It can be understood that, since the third capillary structure is stacked with the first capillary structure and the second capillary structure in the first direction respectively, the overall thickness of the wick can be the sum of the thicknesses of the first capillary structure and the third capillary structure along the first direction, or the sum of the thicknesses of the second capillary structure and the third capillary structure along the first direction.

[0024] In practical applications, the thicknesses of the first capillary structure and the second capillary structure in the first direction can be the same or different.

[0025] In some embodiments of the first aspect, the first capillary structure and the second capillary structure have at least one lap joint region along the second direction; the first capillary structure has a first lap joint portion in the lap joint region, and the second capillary structure has a second lap joint portion in the lap joint region, which are stacked with each other along the first direction.

[0026] It can be understood that the lap joint region between the first capillary structure and the second capillary structure can reduce the gap between the first capillary structure and the second capillary structure, so that the liquid working medium can return smoothly from the first capillary structure to the second capillary structure, and the flow resistance of the liquid return is reduced.

[0027] In some embodiments of the first aspect, the sum of the thicknesses of the first lap joint portion and the second lap joint portion along the first direction is greater than or equal to the thickness of the first capillary structure along the first direction or the thickness of the second capillary structure along the first direction.

[0028] It can be understood that, in different lap joint modes, the lap joint region has different forms. Therefore, the sum of the thicknesses of the first lap joint portion and the second lap joint portion along the first direction in the lap joint region can be equal to the thickness of the first capillary structure or the second capillary structure along the first direction, or can be greater than the thickness of the first capillary structure or the second capillary structure along the first direction.

[0029] In a case where the first capillary structure or the second capillary structure has a thickness along the first direction greater than the first thickness, the overall thickness of the wick can be ensured not to be excessively large by controlling the thickness of the third capillary structure along the first direction.

[0030] In some embodiments of the first aspect, the first lap joint portion includes a plurality of first sub-portions arranged at intervals, and the second lap joint portion includes a plurality of second sub-portions arranged at intervals, the plurality of first sub-portions being arranged alternately with the plurality of second sub-portions.

[0031] It can be understood that the first lap joint portion and the second lap joint portion are arranged alternately, which helps to reduce the liquid backflow flow resistance and the vapor flow resistance.

[0032] In the second aspect, the embodiments of the present application provide a vapor chamber, including the wick of the first aspect and a shell, the wick being arranged in a cavity of the shell.

[0033] It can be understood that the vapor chamber of the embodiments of the present application adopts the wick of the first aspect, wherein the second capillary structure as the evaporation end of the vapor chamber can improve the evaporation speed of the evaporation end, and under the action of the strong capillary force of the first capillary structure and the third capillary structure, the rapid return of the working medium can be ensured, and the dry burning of the evaporation end and the like can be avoided.

[0034] In the third aspect, the embodiments of the present application provide an electronic device, including the vapor chamber of the second aspect and a power device, the vapor chamber being used for heat dissipation of the power device.

[0035] It can be understood that the vapor chamber of the second aspect is assembled in the electronic device, which can meet the heat dissipation requirement of the power device in the electronic device.

[0036] In some embodiments of the third aspect, in a first plane perpendicular to the first direction, a projection of the second capillary structure in the vapor chamber covers a projection of the power device.

[0037] In some embodiments of the third aspect, in the first plane perpendicular to the first direction, the projection of the second capillary structure in the vapor chamber only partially overlaps with the projection of the power device.

[0038] In some embodiments of the third aspect, in the first plane perpendicular to the first direction, the size of the second capillary structure is greater than or equal to the size of the power device.

[0039] It can be understood that the higher the overlap between the projection of the second capillary structure and the projection of the power device in the first plane, the larger the effective contact area between the power device and the vapor chamber, so that the heat on the surface of the power device can be effectively absorbed to achieve heat dissipation. The first plane can be the XY plane mentioned in the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0040] FIG. 1 shows a schematic diagram of the application of a vapor chamber on an electronic device according to some examples of the present application;

[0041] FIG. 2 shows a cross-sectional view of a vapor chamber in the thickness direction according to some examples of the present application;

[0042] FIG. 3 shows a schematic diagram of the structure of a vapor chamber according to some examples of the present application;

[0043] FIG. 4A shows a schematic diagram of a cross-section of a wick 11 along the direction of M-M’ shown in FIG. 3 according to some examples of the present application;

[0044] FIG. 4B shows another schematic diagram of a cross-section of a wick 11 along the direction of M-M’ shown in FIG. 3 according to some examples of the present application;

[0045] FIG. 5 shows a schematic diagram of the internal structure of a second capillary structure according to some examples of the present application;

[0046] FIG. 6A shows a schematic diagram of the overlapping manner between a first capillary structure 111 and a second capillary structure 112 according to some examples of the present application;

[0047] FIG. 6B shows another schematic diagram of the overlapping manner between a first capillary structure 111 and a second capillary structure 112 according to some examples of the present application;

[0048] FIG. 7 shows several cross-sectional views along the direction of B-B’ in FIG. 6A according to some examples of the present application;

[0049] FIG. 8 shows a schematic diagram of an overlapping area with a hollow pattern according to some examples of the present application;

[0050] FIG. 9 shows two cross-sectional views along the direction of C-C’ in FIG. 8 according to some examples of the present application;

[0051] FIG. 10A shows a schematic diagram of the relative position between a first vapor chamber and a heat source according to some examples of the present application;

[0052] FIG. 10B shows a schematic diagram of the relative position between a first vapor chamber and a heat source from another perspective according to some examples of the present application;

[0053] FIG. 11A shows a schematic diagram of the relative position between a second vapor chamber and a heat source according to some examples of the present application;

[0054] FIG. 11B shows a schematic diagram of the relative position between a second vapor chamber and a heat source from another perspective according to some examples of the present application;

[0055] FIG. 12 shows a preparation process of a wick according to some examples of the present application;

[0056] FIG. 13 shows a structural schematic diagram of another vapor chamber according to some examples of the present application;

[0057] FIG. 14 shows a cross-sectional schematic diagram of a wick along the direction of N-N’ in FIG. 13 according to some examples of the present application. DETAILED DESCRIPTION

[0058] Illustrative embodiments of the present application include, but are not limited to, a wick, a vapor chamber, and an electronic device.

[0059] It can be understood that the electronic device of the embodiments of the present application can include, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a camera, an ultra mobile personal computer (UMPC), a handheld computer, a television, a walkie-talkie, a netbook, a POS machine, a personal digital assistant (PDA), a wearable device, a virtual reality device, a smart vehicle, a smart robot, an industrial device, a display screen, a server, and the like, which has a high-power device, where the high-power device can be a central processing unit (CPU), a graphics processing unit (GPU), or a power supply, etc., and the present application does not limit this.

[0060] Please refer to FIG. 1, which shows a schematic diagram of the application of a vapor chamber in an electronic device. As shown in FIG. 1, a computer 01 is internally provided with a vapor chamber 011, and a mobile phone 02 is internally provided with a vapor chamber 021, and the vapor chamber 011 and the vapor chamber 021 are both in a flat sheet shape. It can be understood that the size and position of the vapor chamber need to be designed in combination with the high-power device that needs to be cooled in the actual electronic device. For example, the vapor chamber 021 in the mobile phone 02 can be arranged on the surface of the mainboard 022, so as to cool the high-power device such as CPU integrated on the mainboard 022.

[0061] It can be understood that the internal space and the device layout of different electronic devices are different, and therefore, the shapes of the vapor chamber 011 and the vapor chamber 021 are different. However, the basic structure and the cooling principle of the vapor chamber 011 and the vapor chamber 021 are similar. The basic structure and the cooling principle of the vapor chamber 011 and the vapor chamber 021 will be introduced below by taking the vapor chamber 021 as an example.

[0062] Please refer to FIG. 2, which is a sectional view of the vapor chamber 021 in the thickness direction (Z direction in the figures). As shown in FIG. 2, the vapor chamber 021 includes an outer shell 0211, a wick 0212, and a working medium, which is a medium substance for realizing mutual conversion between thermal energy and mechanical energy. The outer shell 0211 is a sealed shell, and the inner part of the outer shell 0211 is a sealed cavity 021a. The wick 0212 is arranged on the inner wall of the outer shell 0211, and the wick 0212 is filled with liquid working medium. By vacuumizing the cavity 021a, the boiling point of the liquid working medium can be reduced, so that the liquid working medium can change phase at a lower temperature, that is, change from a liquid state to a vapor state. In FIG. 2, the solid arrow represents the flow direction of the liquid working medium, and the dashed arrow represents the flow direction of the vapor working medium (steam).

[0063] In the vertical direction along the Z direction (for example, the X direction shown in the figure), one end of the vapor chamber 021 is a condensation end, and the other end is an evaporation end. The evaporation end can refer to the part that directly or indirectly contacts the heat source such as a high-power device in the mobile phone 02. The liquid working medium at the evaporation end absorbs heat and evaporates into a vapor state, then fills the entire cavity 021a, and runs to the condensation end according to the flow direction indicated by the dashed arrow to condense into a liquid state and release heat. The wick 0212 adopts a capillary structure, so that the liquid working medium after condensation flows back to the evaporation end under the action of the capillary force of the wick 0212 according to the direction indicated by the solid arrow. This process is repeated, and the heat dissipation problem of the mobile phone 02 is solved through phase change heat transfer.

[0064] In some embodiments, the capillary structure of the wick 0212 is a single capillary structure, for example, a single metal mesh structure or a mesh structure sintered by a single metal powder. The metal mesh is a mesh structure formed by interweaving metal wires. Metal powder sintering refers to a sintering process of metal powder, so that the metal powder is bonded to form a structure with a certain strength.

[0065] It can be understood that if the capillary force of the wick 0212 is not enough, the speed of the liquid working medium flowing back to the evaporation end (hereinafter referred to as the liquid return speed) will be affected, which may cause the vapor chamber 021 to dry out, fail, and other problems. However, the greater the capillary force, the smaller the pore size of the capillary structure is required. Generally, the smaller the pore size, the lower the porosity. The higher the porosity, the lower the degree of compaction, and the more breathable the material is. However, if the porosity of the wick 0212 is too low, the evaporation speed of the liquid working medium at the evaporation end will be reduced, which may affect the cooling speed. Therefore, the single capillary structure of the wick 0212 cannot meet the requirements of the liquid return speed and the evaporation speed at the same time, which may cause the heat dissipation effect of the vapor chamber 021 to be poor.

[0066] Based on this, the application provides a kind of liquid absorption core, the liquid absorption core has multiple capillary structures, multiple capillary structures are arranged in mutual lap, while ensuring that liquid working medium can flow between multiple capillary structures, so that liquid absorption core can meet the requirements of liquid return speed and evaporation speed simultaneously.For example, multiple capillary structures can include first capillary structure, second capillary structure and third capillary structure, third capillary structure is stacked with first capillary structure and second capillary structure in the first direction (for example, Z direction), first capillary structure and second capillary structure are mutually lapped in the second direction (for example, X direction), and the second direction is perpendicular to the first direction.Capillary force of first capillary structure and third capillary structure is stronger to meet the requirement of liquid return speed.Capillary structure of second capillary structure has higher porosity to meet the requirement of evaporation speed.In this way, when liquid absorption core is used as part of the vapor chamber and assembled on electronic equipment, second capillary structure as the evaporation end of the vapor chamber can improve the evaporation speed of the evaporation end, and under the action of strong capillary force of first capillary structure and third capillary structure, the rapid return of working medium can be ensured.

[0067] It can be understood that the capillary force and porosity of the structure obtained by processing the metal material with different processes can be different.Therefore, the first capillary structure and the second capillary structure described above can be metal structures obtained by different processes, for example, the first capillary structure and the third capillary structure can use metal mesh or sintered metal powder to ensure strong capillary force, and the second capillary structure can use preformed foam metal or be made by electrodeposition of metal to ensure high porosity.

[0068] Next, combined with FIGS. 3 to 11B, the first embodiment of the liquid absorption core of the application will be described in detail.

[0069] First, refer to FIG. 3, which shows a structure schematic diagram of a vapor chamber 10 using the liquid absorption core of the embodiment. It should be noted that FIG. 3 is a cross-sectional view of the vapor chamber 10 along the XZ plane.

[0070] As shown in FIG. 3, the vapor chamber 10 includes a liquid absorption core 11 and an outer shell 12, wherein the outer shell 12 is a sealed shell, and the cross-section is in the shape of a "mouth character". The inner part of the outer shell 12 is a closed cavity 10a. The liquid absorption core 11 is arranged on the inner wall of the outer shell 12, and the liquid absorption core 11 is filled with liquid working medium.

[0071] As can be seen from FIG. 2, the flow field of the working medium in the vapor chamber 10 is different from that in the vapor chamber 021. In the vapor chamber 021, the working medium circulates from one end to the other end to realize heat dissipation. In the vapor chamber 10, the working medium circulates from the center to the two ends to realize heat dissipation. That is, both ends of the vapor chamber 10 along the X direction are condensation ends, and the center is an evaporation end.

[0072] For the convenience of description, the vapor flow direction in the vapor chamber 10 is taken into account, and the vapor chamber 10 is divided into a heat source region and a heat dissipation region. Referring to FIGS. 4A and 4B, both of which are schematic views of the projection of some possible vapor chambers 10 on the XY plane, the Y direction is perpendicular to the X direction and the Z direction, respectively. For example, as shown in FIG. 4A, the projection region of the vapor chamber 10 on the XY plane is a rectangular region A, and with reference to the vapor flow direction indicated by the arrows, the central shaded region of the rectangular region A can be the heat source region A1, and the annular region surrounding the central shaded region can be the heat dissipation region A2. Alternatively, as shown in FIG. 4B, the projection region of the vapor chamber 10 on the XY plane is a rectangular region A, and with reference to the vapor flow direction indicated by the arrows, the central shaded region of the rectangular region A can be the heat source region A1, and the two side regions can be the heat dissipation region A2. It can be understood that in other embodiments, the vapor chamber 10 can have different division regions of the heat source region and the heat dissipation region, which are not limited in the present application.

[0073] With continued reference to FIG. 3, the wick 11 includes a first capillary structure 111, a second capillary structure 112, and a third capillary structure 113, wherein the third capillary structure 113 is stacked with the first capillary structure 111 and the second capillary structure 112 in the Z direction, respectively, and the first capillary structure 111 and the second capillary structure 112 are overlapped in the X direction. Among them, the first capillary structure 111 and the second capillary structure 112 overlapped in the X direction can mean that the first capillary structure 111 and the second capillary structure 112 at least partially overlap in the X direction, in other words, the overlapping part of the first capillary structure 111 and the second capillary structure 112 are stacked in the Z direction. And the first capillary structure 111 is located in the heat dissipation region A2, the overlapping part of the second capillary structure 112 with the first capillary structure 111 is located in the heat dissipation region A2, the rest is located in the heat source region A1, part of the third capillary structure 113 is located in the heat source region A1, and part is located in the heat dissipation region A2.

[0074] In some embodiments, the size of the third capillary structure 113 in the X direction is greater than the size of the second capillary structure 112 in the X direction. In this way, the part of the third capillary structure 113 located in the heat source region A1 can be used together with the second capillary structure 112 to accelerate the evaporation of the liquid working medium, and the part of the third capillary structure 113 located in the heat dissipation region A2 can be used together with the first capillary structure 111 to accelerate the return flow of the liquid working medium.

[0075] The positional relationship between the first capillary structure 111 and the second capillary structure 112 can be referred to FIG. 4A or FIG. 4B. FIG. 4A and FIG. 4B are two cross-sectional schematic views of the wick 11 along the direction of M-M' shown in FIG. 3. For example, the first capillary structure 111 is arranged around the second capillary structure 112, or in other words, the center of the first capillary structure 111 is a hollow region, and the second capillary structure 112 is arranged in the hollow region. The projection area of the third capillary structure 113 on the XY plane covers the heat source area A1 and at least part of the heat dissipation area A2. In some embodiments, the projection area of the third capillary structure 113 on the XY plane can cover the projection areas of the first capillary structure 111 and the second capillary structure 112 on the XY plane. The structure of the first capillary structure 111, the second capillary structure 112 and the third capillary structure 113 and the lapping manner therebetween will be further described below, which will not be described here in detail.

[0076] In some embodiments, the first capillary structure 111 has a strong capillary force to facilitate the return flow of the liquid. For example, the first capillary structure 111 is a metal mesh structure, or a sintered metal powder structure. Specifically, the metal mesh and the metal powder / powder strip mentioned in the present application include but are not limited to copper, aluminum and other materials with high thermal conductivity.

[0077] In some embodiments, the pore size of the second capillary structure 112 adopts a bimodal design. That is, as can be clearly seen from the pore size distribution curve of the second capillary structure 112, the second capillary structure 112 has two kinds of pore sizes with a large number of distributions, and the two kinds of pore sizes are different in size and can meet the requirements of high capillary force and high porosity. For example, the second capillary structure 112 can be a preformed foam metal, or formed by electrodeposition of metal. For example, FIG. 5 is a schematic view of the internal structure of a second capillary structure 112 using a foam metal. As can be seen from FIG. 5, the foam metal has different sizes of pores distributed therein. In this way, the second capillary structure 112 can have a strong capillary force to quickly return the working fluid and quickly evaporate the heat, thereby improving the maximum heat dissipation capacity of the vapor chamber 10.

[0078] In some embodiments, the third capillary structure 113 can adopt a metal mesh structure, or a sintered metal powder strip / powder structure, to assist the rapid return flow of the liquid. The third capillary structure 113 can adopt the same capillary structure as the first capillary structure 111, for example, both adopt a metal mesh structure, or different capillary structures.

[0079] In some embodiments, the first capillary structure 111, the second capillary structure 112 and the third capillary structure 113 described above can be combined by sintering to form the overall structure of the wick 11.

[0080] In this way, the wick 11 can be compatible with different capillary structures by coupling the different capillary structures, and can achieve optimal capillary force, minimum liquid flow resistance, and minimum vapor flow resistance design, so that the performance of the vapor chamber 10 is optimized.

[0081] In actual applications, the electronic device using the vapor chamber 10 is experimentally verified, and the vapor chamber 10 containing the wick 11 has improved heat source junction temperature benefits and whole machine transient Turbo performance. Specifically, the junction temperature benefits can be improved by more than 2°C, and the Turbo performance can be improved by more than 3s.

[0082] In some embodiments, the thickness of the wick 11 in the Z direction is 0.58mm-0.62mm. The thickness of the first capillary structure 111 and the second capillary structure 112 in the Z direction is 0.18mm-0.22mm, and the thickness of the third capillary structure 113 in the Z direction is 0.38mm-0.42mm. For example, the thickness of the wick 11 in the Z direction is 0.6mm. The thickness of the first capillary structure 111 and the second capillary structure 112 in the Z direction is 0.2mm, and the thickness of the third capillary structure 113 in the Z direction is 0.4mm.

[0083] It should be noted that the shape of the first capillary structure 111, the second capillary structure 112, and the third capillary structure 113 is not limited in the present application. For example, the shape of the second capillary structure 112 and the corresponding heat source area A1 can be any regular or irregular shape such as a rectangle or a circle. For ease of description, the projection shape of the first capillary structure 111 in the XY plane is "mouth-shaped", the projection shape of the second capillary structure 112 is rectangular, and the projection shape of the third capillary structure 113 is rectangular as an example.

[0084] As described above, the first capillary structure 111 and the second capillary structure 112 are overlapped in the X direction. Please refer to FIGS. 6A and 6B, which respectively show different overlapping modes between the first capillary structure 111 and the second capillary structure 112.

[0085] In some embodiments, as shown in FIG6A, the first capillary structure 111 and the second capillary structure 112 overlap not only in the X direction but also in the Y direction. It can be understood that the first capillary structure 111 is arranged around the second capillary structure 112; therefore, the overlap area between the first capillary structure 111 and the second capillary structure 112 can be "U-shaped". Specifically, the first capillary structure 111 and the second capillary structure 112 have a first overlap area 11-1 and a second overlap area 11-2 in the X direction, and a third overlap area 11-3 and a fourth overlap area 11-4 in the Y direction. The first overlap area 11-1, the second overlap area 11-2, the third overlap area 11-3, and the fourth overlap area 11-4 correspond to the four sides of the "U-shape".

[0086] It is understandable that by setting the overlap area between the first capillary structure 111 and the second capillary structure 112, it can be ensured that there is no gap between the first capillary structure 111 and the second capillary structure 112, so that the liquid working fluid can flow smoothly from the first capillary structure 111 to the second capillary structure 112, reducing the flow resistance of liquid reflux.

[0087] It should be noted that in other embodiments of this application, the first capillary structure 111 and the second capillary structure 112 may have at least one of the above-mentioned first overlapping region 11-1, second overlapping region 11-2, third overlapping region 11-3 and fourth overlapping region 11-4.

[0088] For example, in some embodiments, as shown in FIG6B, the first capillary structure 111 and the second capillary structure 112 have a first overlapping region 11-1 and a second overlapping region 11-2 in the X direction, and only a fourth overlapping region 11-4 in the Y direction.

[0089] It is understood that in any overlapping area between the first capillary structure 111 and the second capillary structure 112, along the Z direction, the first capillary structure 111 may overlap the second capillary structure 112, or the second capillary structure 112 may overlap the first capillary structure 111.

[0090] The following section uses the first overlapping region 11-1 and the second overlapping region 11-2 in the X direction as examples to introduce several different overlapping structures. Please refer to Figure 7, which shows several cross-sectional views along the B-B' direction in Figure 6A.

[0091] As shown in (a) and (c) of FIG. 7, the first capillary structure 111 is overlapped on the second capillary structure 112. As shown in (b) and (d) of FIG. 7, the second capillary structure 112 is overlapped on the first capillary structure 111. In general, the first capillary structure 111 is stacked with the second capillary structure 112 in the Z direction at the overlapping portion 111-1 of the first overlapping region 11-1.

[0092] For example, referring to (a) and (b) of FIG. 7, in the first overlapping region 11-1, the sum of the thicknesses of the overlapping portion 111-1 and the overlapping portion 112-1 in the Z direction is equal to the thickness of the first capillary structure 111 or the second capillary structure 112 in the Z direction.

[0093] For example, referring to (c) and (d) of FIG. 7, in the first overlapping region 11-1, the sum of the thicknesses of the overlapping portion 111-1 and the overlapping portion 112-1 in the Z direction is greater than the thickness of the first capillary structure 111 or the second capillary structure 112 in the Z direction.

[0094] The second overlapping region 11-2 is similar, and will not be repeated here.

[0095] In the above embodiment, referring to FIGS. 6A and 6B, each of the overlapping regions is a continuous pattern, i.e., the first capillary structure 111 and the second capillary structure 112 in the overlapping region are continuous solid structures. In other embodiments, at least one of the overlapping regions can also have a hollow pattern, i.e., the first capillary structure 111 or the second capillary structure 112 in the overlapping region can be a discontinuous solid structure. For example, referring to FIG. 8, FIG. 8 shows a schematic view of an overlapping region having a hollow pattern. It should be noted that the hollow pattern can include but is not limited to the rectangular shape shown in the figure, and can also be a regular or irregular shape such as a circle, a triangle, etc.

[0096] As shown in FIG. 8, the first overlapping region 11-1 to the fourth overlapping region 11-4 all have a rectangular hollow pattern, and each of the overlapping regions has a "Great Wall zigzag" shape.

[0097] Figure 9 is two cross-sectional views of the C-C' direction in Figure 8. As shown in (a) of Figure 9, in the fourth overlap region 11-4, the second capillary structure 112 overlaps the first capillary structure 111. The second capillary structure 112 in the overlap portion of the fourth overlap region 11-4 (an example of a second overlap portion) includes a plurality of sub-portions 1121 (an example of a second sub-portion) arranged at intervals, of which three sub-portions 1121 are shown as an example. It can be understood that the first capillary structure 111 is filled between adjacent sub-portions 1121, and thus the first capillary structure 111 is also in the overlap portion of the fourth overlap region 11-4 (an example of a first overlap portion) and includes a plurality of sub-portions 1111 (an example of a first sub-portion) arranged at intervals, of which two sub-portions 1111 are shown as an example.

[0098] As shown in (b) of Figure 9, in the fourth overlap region 11-4, the first capillary structure 112 overlaps the first capillary structure 111. The first capillary structure 111 in the overlap portion of the fourth overlap region 11-4 (an example of a first overlap portion) includes a plurality of sub-portions 1111 (an example of a first sub-portion) arranged at intervals, of which three sub-portions 1111 are shown as an example. It can be understood that the second capillary structure 112 is filled between adjacent sub-portions 1111, and thus the second capillary structure 112 is also in the overlap portion of the fourth overlap region 11-4 (an example of a second overlap portion) and includes a plurality of sub-portions 1121 (an example of a second sub-portion) arranged at intervals, of which two sub-portions 1121 are shown as an example.

[0099] As can be seen from Figure 9, the plurality of sub-portions 1121 of the second capillary structure 112 in the fourth overlap region are arranged in an interlaced manner with the plurality of sub-portions 1111 of the first capillary structure 111 in the fourth overlap region.

[0100] The advantage of the hollow design is that the area of the overlap region between the first capillary structure 111 and the second capillary structure 112 can be reduced, which helps to reduce the liquid backflow flow resistance and the vapor flow resistance.

[0101] Continuing to refer to Figure 6A, the size x1 of the first overlap region 11-1 in the X direction, the size x2 of the second overlap region 11-2 in the X direction, the size y3 of the third overlap region 11-3 in the Y direction, and the size y4 of the fourth overlap region 11-4 in the Y direction can be completely the same or not completely the same. For example, as shown in Figure 6B, the size x1 of the first overlap region 11-1 in the X direction can be equal to the size x2 of the second overlap region 11-2 in the X direction, and both are greater than the size y4 of the fourth overlap region 11-4 in the Y direction.

[0102] Referring to FIG. 10A and FIG. 10B, FIG. 10A and FIG. 10B respectively show the relative position between the vapor chamber 10 and a heat source (e.g. a CPU) 100 from different perspectives. As shown in FIG. 10A, the housing 12 includes a first cover plate 121 and a second cover plate 122 along the Z direction, and a cavity 10a is formed between the first cover plate 121 and the second cover plate 122. The wick 11 is disposed on the second cover plate 122, and the second cover plate 122 is in contact with the CPU 100, which is below the second capillary structure 112.

[0103] As shown in FIG. 10A, the surface of the second capillary structure 112 in contact with the second cover plate 122 along the Z direction is a first heat source surface 112a, and the surface away from the second cover plate 122 is a second heat source surface 112b. The size of the first heat source surface 112a and / or the second heat source surface 112b is greater than or equal to the size of the CPU 100. For example, along the X direction, the size x112a of the first heat source surface 112a and the size x112b of the second heat source surface 112b are both greater than the size x100 of the CPU. In this way, since the CPU has a large enough contact area with the vapor chamber 10, it can be ensured that all the heat on the surface of the CPU can enter the interior of the vapor chamber 10 through the first heat source surface 11a, thereby achieving heat dissipation.

[0104] As shown in FIG. 10B, along the X direction, the size x112a of the first heat source surface 112a and the size x112b of the second heat source surface 112b are both greater than the size x100 of the CPU, and along the Y direction, the size y112a of the first heat source surface 112a and the size y112b of the second heat source surface 112b are both greater than the size y100 of the CPU. For example, in the X and Y directions, the size of the CPU can be 100mm*200mm, and the size of the second heat source surface 112b can be 12mm*22mm. In other words, in some embodiments, the projection of the first heat source surface 112a and the second heat source surface 112b on the XY plane covers the projection of the CPU 100.

[0105] FIG. 11A and FIG. 11B show another schematic diagram of the relative position between the vapor chamber 10 and the CPU 100. The structure of the vapor chamber 10 shown in FIG. 11A is the same as that of the vapor chamber 10 shown in FIG. 10A, and therefore, regarding the size of the first heat source surface and the second heat source surface of the second capillary structure 112, reference can be made to the related embodiments of FIG. 10A. The difference between FIG. 10A, FIG. 10B and FIG. 11A, FIG. 11B is that, in this example, the CPU 100 is below the overlap region 11-1 between the first capillary structure 111 and the second capillary structure 112. That is, referring to FIG. 11B, if the size of the CPU 100 in the X direction is greater than the size of the overlap region 11-1, then in the XY plane, the projection of the first heat source surface 112a and / or the second heat source surface 112b only partially overlaps with the projection of the CPU 100.

[0106] It can be understood that the size of the first heat source surface 11a and the second heat source surface 112b of the second capillary structure 112 in the vapor chamber 10 is greater than or equal to the CPU 100, and when the projection of the first heat source surface 112a or the second heat source surface 112b on the XY plane completely covers the CPU 100, the heat of the CPU 100 can be completely absorbed by the second capillary structure 112, achieving the best heat dissipation effect.

[0107] The preparation process of the wick 11 will be described below in combination with FIG. 12. As shown in (a) of FIG. 12, first, the metal powder is sintered on the second cover plate 122 to form the first capillary structure 111. It can be understood that in other embodiments, the preparation of the wick 11 can be first completed on other substrates, and then transferred to the second cover plate 122 as a whole and sintered with the second cover plate 122. As shown in (b) of FIG. 12, the first capillary structure 111 is slotted to form the groove 111a. The cross section of the groove 111a can be in the shape of "inverted convex", or in the shape of "convex" or rectangular as shown in other figures of FIG. 7, depending on the structure design of the actual lap joint area. As shown in (c) of FIG. 12, the preformed foam metal is filled in the groove 111a, or the metal is directly electrodeposited in the groove 111a to form the second capillary structure 112. Secondly, as shown in (d) of FIG. 12, the metal powder is sintered on the surface of the first capillary structure 111 and the second capillary structure 112 to form the third capillary structure 113, thereby obtaining the wick 11.

[0108] In this embodiment, the wick 11 is coupled by the lap joint of different capillary structures, which can be compatible with the advantages of different capillary structures, achieve the best capillary force, the smallest liquid flow resistance and the smallest vapor flow resistance design, and make the performance of the vapor chamber 10 optimal.

[0109] The second embodiment of the wick of the present application will be described in detail below in combination with FIG. 13 and FIG. 14.

[0110] Please refer to FIG. 13, which shows a structure schematic diagram of a vapor chamber 20 applying the wick of the present embodiment. As shown in FIG. 13, the vapor chamber 20 comprises a wick 21 and a shell 22, the wick 21 is arranged on the inner wall of the shell 22, and the wick 21 is filled with liquid working medium. The inside of the shell 22 is a closed cavity 20a, and the structure of the shell 22 is the same as that of the shell 21, which can be referred to the embodiments of the shell 21, and the present embodiment will not be described again.

[0111] The difference between the vapor chamber 20 and the vapor chamber 10 is that the working medium in the vapor chamber 20 circulates from one end to the other end to achieve heat dissipation, that is, one end of the vapor chamber 20 along the X direction is the condensation end, and the other end is the evaporation end. The flow field of the working medium circulation in the vapor chamber 20 is similar to that of the vapor chamber 021.

[0112] For the convenience of description, the vapor flow direction in the vapor chamber 20 is taken into account, and the vapor chamber 20 is divided into a heat source area and a condensation area. Referring to FIG. 14, which is a schematic view of a cross section along the direction of N-N' shown in FIG. 13. As shown in FIG. 14, for example, the projection area of the vapor chamber 20 on the XY plane is a rectangular area A. Referring to the vapor flow direction shown by the arrow, the right side of the rectangular area D is the heat source area D1, and the left side is the heat dissipation area D2.

[0113] Continuing to refer to FIG. 13, the wick 21 includes a first capillary structure 211, a second capillary structure 212, and a third capillary structure 213. The third capillary structure 213 is stacked with the first capillary structure 211 and the second capillary structure 212 in the Z direction, respectively, and the first capillary structure 211 and the second capillary structure 212 are overlapped in the X direction. The meaning of the overlap can be referred to the above embodiments, which will not be described here. Specifically, the first capillary structure 211 and the second capillary structure 212 have an overlap area 21-1 in the X direction. Moreover, the first capillary structure 211 is located in the heat dissipation area D2, and the overlapping part of the second capillary structure 212 with the first capillary structure 211 is located in the heat dissipation area D2, and the rest part is located in the heat source area D1. Part of the third capillary structure 213 is located in the heat source area D1, and part is located in the heat dissipation area D2.

[0114] The positional relationship between the first capillary structure 211 and the second capillary structure 212 can be referred to FIG. 14. For example, the first capillary structure 211 and the second capillary structure 212 are arranged in sequence or adjacent in the X direction.

[0115] The structure, material, and overlapping mode between the first capillary structure 211, the second capillary structure 212, and the third capillary structure 213 can be referred to the structure, material, and overlapping mode between the first capillary structure 111, the second capillary structure 112, and the third capillary structure 113 described above. For example, the overlap area 21-1 can be referred to the specific embodiments of the overlap area 11-1, which will not be described here.

[0116] It can be understood that the wick 21 can be coupled by the overlapping of different capillary structures, and can be compatible with the advantages of different capillary structures, so as to achieve the best capillary force, the smallest liquid flow resistance, and the smallest vapor flow resistance design, so that the performance of the vapor chamber 20 is optimized.

[0117] It can be understood that the embodiments of the present application also provide an electronic device, which is equipped with the above-mentioned vapor chamber 10 or vapor chamber 20. The vapor chamber 10 or vapor chamber 20 can dissipate heat from the heat source such as a high-power device in the electronic device, so as to ensure the normal operation of various functions of the electronic device.

[0118] In the above description of this embodiment, unless otherwise stated, " / " means "or". For example, A / B can identify A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, B exists alone, and A and B exist simultaneously.

[0119] It should be noted that in the examples and description of this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0120] Although this application has been illustrated and described with reference to certain preferred embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made thereto without departing from the scope of this application.

Claims

1. A wick, comprising: The first capillary structure, the second capillary structure, and the third capillary structure are stacked along a first direction. The third capillary structure is stacked along the first direction with the first capillary structure and the second capillary structure, and the first capillary structure is overlapped with the second capillary structure along a second direction. The porosity of the second capillary structure is greater than the porosity of the first capillary structure and the porosity of the third capillary structure.

2. The wick of claim 1, wherein The first capillary structure is a metal mesh structure or a sintered metal powder structure.

3. The wick of claim 2, wherein, The second capillary structure is a preformed foam metal structure or formed by electrodeposition of metal.

4. The wick of claim 3, wherein, The pore size of the second capillary structure is bimodal distribution.

5. The wick of claim 3, wherein The third capillary structure is a metal mesh structure or a sintered metal powder structure.

6. The wick of any one of claims 1-5, wherein, The capillary force of the first capillary structure and the capillary force of the third capillary structure are greater than the capillary force of the second capillary structure.

7. The wick of any one of claims 1-5, wherein, The size of the third capillary structure in the second direction is greater than the size of the second capillary structure in the second direction.

8. The wick of any one of claims 1-5, wherein, The thickness of the wick along the first direction is equal to the sum of the thickness of the first capillary structure or the second capillary structure along the first direction and the thickness of the third capillary structure along the first direction.

9. The wick of any one of claims 1-5, wherein, The first capillary structure and the second capillary structure have at least one overlapping area along the second direction. The first capillary structure is located in a first overlapping part of the overlapping area, and the second capillary structure is located in a second overlapping part of the overlapping area, which are stacked along the first direction.

10. The wick of claim 9, wherein, The sum of the thickness of the first overlapping part and the second overlapping part along the first direction is greater than or equal to the thickness of the first capillary structure along the first direction or the thickness of the second capillary structure along the first direction.

11. The wick of claim 9, wherein The first overlapping part includes a plurality of first sub-parts arranged at intervals, and the second overlapping part includes a plurality of second sub-parts arranged at intervals, and the plurality of first sub-parts and the plurality of second sub-parts are arranged alternately.

12. A vapor chamber, characterized by, The wick of any one of claims 1-11 and a shell, the wick is arranged in a cavity of the shell.

13. An electronic device, comprising: The uniform temperature plate of claim 12 and a power device, the uniform temperature plate is used for dissipating heat of the power device.

14. The electronic device of claim 13, wherein, In a first plane perpendicular to the first direction, the projection of the second capillary structure in the uniform temperature plate covers the projection of the power device.

15. The electronic device of claim 13, wherein, In a first plane perpendicular to the first direction, the projection of the second capillary structure in the uniform temperature plate only partially overlaps the projection of the power device.

16. The electronic device of any of claims 13-15, wherein, In a first plane perpendicular to the first direction, the size of the second capillary structure is greater than or equal to the size of the power device.

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