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

Wicks, Vapor Chambers, and Electronics

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 12, 2024, with application number 202410294505.7 and application name “Liquid Absorbent Core, Temperature Equalizing Plate and Electronic Device”. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of heat dissipation technology, and in particular to a liquid wick, a temperature homogenizing plate and an electronic device. Background Art

[0003] As the performance of electronic devices such as mobile phones and computers continues to grow, their power consumption also increases. To ensure the user's thermal experience and the temperature reliability of electronic devices, the heat dissipation requirements for electronic devices are becoming increasingly stringent. Currently, the industry often uses vapor chambers (VCs) to solve this heat dissipation problem.

[0004] The vapor chamber is a sealed cavity containing a capillary wick and a working medium. When the vapor chamber is operating, the liquid working medium at the evaporation end, near the heat source, absorbs heat and evaporates, transforming into a vapor that moves to the condensation end, where it condenses into a liquid and releases heat. The liquid working medium then returns to the evaporation end under the capillary action of the capillary wick, repeating this cycle to transfer heat from the evaporation end to the condensation end for dissipation.

[0005] However, as electronic devices consume increasing power, the heat flux density at the evaporation end increases, meaning a large amount of liquid working fluid evaporates into vapor in a short period of time. This places higher demands on the capillary structure of the wick. Therefore, a new capillary structure for the wick is urgently needed to ensure the heat dissipation effect of the vapor chamber on electronic devices. Summary of the Invention

[0006] In order to meet the heat dissipation requirements of electronic devices, embodiments of the present application provide a liquid wick, a temperature homogenizing plate, and an electronic device.

[0007] In a first aspect, an embodiment of the present application provides a liquid-absorbing core, 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 respectively along a first direction, the first capillary structure and the second capillary structure overlap each other along a second direction, and the first direction and the second direction are perpendicular to each other; and the porosity of the second capillary structure is respectively greater than the porosity of the first capillary structure and the porosity of the third capillary structure.

[0008] It is understood that the wick of the present embodiment, through the overlapping coupling of different capillary structures, can combine the advantages of different capillary structures. For example, the first and third capillary structures have stronger capillary forces to meet the requirements for liquid return speed. The second capillary structure has a higher porosity to meet the requirements for evaporation speed. In this way, the optimal capillary force, minimum liquid flow resistance, and minimum vapor flow resistance can be designed to achieve the best performance of the vapor chamber.

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

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

[0011] In this way, the first capillary structure has a stronger capillary force, which can increase the reflux speed of the liquid working medium.

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

[0013] In this way, the second capillary structure can ensure a higher porosity and increase the evaporation rate of the liquid working medium.

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

[0015] It can be understood that the bimodal pore design of the second capillary structure can simultaneously meet the requirements of higher capillary force and higher porosity, thereby increasing both the reflux rate of the liquid working medium and the evaporation rate of the liquid working medium.

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

[0017] In this way, the third capillary structure has a strong capillary force, which can increase the return flow rate of the liquid working medium. It is 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 through the overlapping of different capillary structures, which can combine the advantages of different capillary structures and help improve the heat dissipation capacity of the temperature vapor chamber.

[0020] In some embodiments of the first aspect above, a dimension of the third capillary structure in the second direction 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 backflow of the liquid working medium, thereby reducing the drying out of the second capillary structure.

[0022] In some embodiments of the first aspect, a thickness of the wick along the first direction is equal to the sum of 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 may be the same or different.

[0025] In some embodiments of the first aspect above, the first capillary structure and the second capillary structure have at least one overlapping area along the second direction; a first overlapping portion of the first capillary structure located in the overlapping area and a second overlapping portion of the second capillary structure located in the overlapping area are stacked on each other along the first direction.

[0026] It can be understood that the overlapping area formed 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 flow back smoothly from the first capillary structure to the second capillary structure, reducing the liquid reflux flow resistance.

[0027] In some embodiments of the first aspect above, the sum of the thicknesses of the first overlapping portion and the second overlapping 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 is understood that the overlapping region has different shapes under different overlapping modes. Thus, the sum of the thicknesses of the first overlapping portion and the second overlapping portion in the overlapping region along the first direction may be equal to the thickness of the first capillary structure or the second capillary structure along the first direction, or may be greater than the thickness of the first capillary structure or the second capillary structure along the first direction.

[0029] In the case where the thickness of the third capillary structure is greater than the thickness of the first capillary structure or the second capillary structure along the first direction, the thickness of the third capillary structure along the first direction can be controlled to ensure that the overall thickness of the absorbent core is not too large.

[0030] In some embodiments of the first aspect above, the first overlapping portion includes a plurality of first sub-portions arranged at intervals, the second overlapping portion includes a plurality of second sub-portions arranged at intervals, and the plurality of first sub-portions and the plurality of second sub-portions are staggered.

[0031] It can be understood that the staggered arrangement of the first overlapping portion and the second overlapping portion helps to reduce the liquid reflux flow resistance and the steam flow resistance.

[0032] In a second aspect, an embodiment of the present application provides a temperature homogenizing plate, comprising the liquid wick of the first aspect and a shell, wherein the liquid wick is disposed in a cavity of the shell.

[0033] It can be understood that the temperature equalizing plate in the embodiment of the present application adopts the liquid absorption core of the first aspect, wherein the second capillary structure serves as the evaporation end of the temperature equalizing plate, which can increase the evaporation rate of the evaporation end, and under the action of the strong capillary force of the first capillary structure and the third capillary structure, it can ensure the rapid return of the working fluid to avoid the occurrence of burning of the evaporation end.

[0034] In a third aspect, an embodiment of the present application provides an electronic device, comprising the temperature vapor chamber and a power device according to the second aspect, wherein the temperature vapor chamber is used to dissipate heat from the power device.

[0035] It can be understood that assembling the temperature vapor chamber according to the second aspect in an electronic device can meet the heat dissipation requirements of power devices in the electronic device.

[0036] In some embodiments of the third aspect above, on 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, on a first plane perpendicular to the first direction, a projection of the second capillary structure in the vapor chamber only partially overlaps with a projection of the power device.

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

[0039] It can be understood that the higher the degree of overlap between the projection of the second capillary structure on the first plane and the projection of the power device, the larger the effective contact area between the power device and the vapor chamber, thereby ensuring that all heat from the surface of the power device is effectively absorbed and heat dissipated. The first plane may be the XY plane mentioned in the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1 is a schematic diagram showing an application of a vapor chamber on an electronic device according to some examples of the present application;

[0041] FIG2 shows a cross-sectional view of a vapor chamber in a thickness direction according to some examples of the present application;

[0042] FIG3 shows a schematic structural diagram of a temperature vapor chamber according to some examples of the present application;

[0043] FIG4A shows a schematic cross-sectional view of a wick 11 along the MM' direction shown in FIG3 according to some examples of the present application;

[0044] FIG4B shows a schematic cross-sectional view of another absorbent core 11 along the MM' direction shown in FIG3 according to some examples of the present application;

[0045] FIG5 is a schematic diagram showing the internal structure of a second capillary structure according to some examples of the present application;

[0046] FIG6A shows a method of overlapping the first capillary structure 111 and the second capillary structure 112 according to some examples of the present application;

[0047] FIG6B shows another overlapping manner between the first capillary structure 111 and the second capillary structure 112 according to some examples of the present application;

[0048] FIG7 shows several cross-sectional views along the BB' direction in FIG6A according to some examples of the present application;

[0049] FIG8 is a schematic diagram showing an overlapping region having a hollow pattern according to some examples of the present application;

[0050] FIG9 shows two cross-sectional views along the CC' direction in FIG8 according to some examples of the present application;

[0051] FIG10A is a schematic diagram showing the relative positions of a first vapor chamber and a heat source according to some examples of the present application;

[0052] FIG10B is a schematic diagram showing the relative positions of the first vapor chamber and the heat source from another perspective according to some examples of the present application;

[0053] FIG11A is a schematic diagram showing the relative positions of a second vapor chamber and a heat source according to some examples of the present application;

[0054] FIG11B is a schematic diagram showing the relative positions of a second vapor chamber and a heat source from another perspective according to some examples of the present application;

[0055] FIG12 shows a process for preparing a wick according to some examples of the present application;

[0056] FIG13 shows a schematic structural diagram of another vapor chamber according to some examples of the present application;

[0057] FIG14 is a schematic cross-sectional view of a liquid absorbent core along the N-N' direction shown in FIG13 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 devices of the embodiments of the present application may include but are not limited to mobile phones, tablet computers, laptop computers, cameras, ultra mobile personal computers (UMPCs), handheld computers, televisions, walkie-talkies, netbooks, POS machines, personal digital assistants (PDAs), wearable devices, virtual reality devices, smart vehicles, smart robots, industrial equipment, display screens, servers, and other devices with high-power devices, among which the high-power devices may be central processing units (CPUs), graphics processing units (GPUs), or power supplies, etc., and the present application does not impose any restrictions on this.

[0060] Please refer to Figure 1, which shows a schematic diagram of a vapor chamber in electronic equipment. As shown in Figure 1, a computer 01 is equipped with a vapor chamber 011, and a mobile phone 02 is equipped with a vapor chamber 021. Both vapor chambers 011 and 021 are flat sheets. It is understood that the size and location of the vapor chambers need to be designed based on the high-power components in the electronic device that require heat dissipation. For example, in mobile phone 02, vapor chamber 021 can be placed on the surface of motherboard 022 to dissipate heat from high-power components such as the CPU integrated into motherboard 022.

[0061] As you can understand, different electronic devices have different internal spaces and device layouts, so the shapes of vapor chambers 011 and 021 differ. However, the basic structures and heat dissipation principles of vapor chambers 011 and 021 are similar. The following uses vapor chamber 021 as an example to explain its basic structure and heat dissipation principles.

[0062] Please refer to Figure 2, which is a cross-sectional view of the temperature equalizing plate 021 in the thickness direction (Z direction shown in each figure). As shown in Figure 2, the temperature equalizing plate 021 includes a shell 0211, a liquid wick 0212 and a working medium. The working medium refers to a medium substance that realizes the mutual conversion of thermal energy and mechanical energy. Among them, the shell 0211 is a sealed shell, and the interior of the shell 0211 is a sealed cavity 021a. The liquid wick 0212 is arranged on the inner wall of the shell 0211, and the liquid wick 0212 is filled with a liquid working medium. By evacuating the cavity 021a, the boiling point of the liquid working medium can be lowered, causing it to undergo a phase change at a lower temperature, that is, from liquid to vapor. The solid arrows in Figure 2 represent the flow direction of the liquid working medium, and the dotted arrows represent the flow direction of the vapor working medium (steam).

[0063] Along the vertical direction of the Z direction (for example, the X direction shown in the figure), one end of the temperature plate 021 is the condensation end and the other end is the evaporation end. Among them, the evaporation end can refer to the part that is in direct or indirect contact with the heat source in the mobile phone 02, such as a high-power device. The liquid working medium at the evaporation end absorbs heat and evaporates, turning into a vapor state and then filling the entire cavity 021a. And according to the flow direction shown by the dotted arrow, it flows to the condensation end and condenses into a liquid state, releasing heat. The liquid wick 0212 adopts a capillary structure, so that the condensed liquid working medium flows back to the evaporation end in the direction shown by the solid arrow under the action of the capillary force of the liquid wick 0212. This process is repeated over and over again, solving the heat dissipation problem of the mobile phone 02 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 formed by sintering a single metal powder. The metal mesh is a mesh structure formed by interwoven metal wires. Metal powder sintering refers to a sintering process in which metal powders are bonded together to form a structure with a certain strength.

[0065] It is understandable that if the capillary force of the wick 0212 is insufficient, it will affect the speed at which the liquid working medium flows back to the evaporation end (hereinafter referred to as the liquid return speed), causing the temperature equalizing plate 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, where the porosity refers to the percentage of the pore volume in the material to the total volume of the material in its natural state. The higher the porosity, the lower the density and the more breathable the material. 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, affecting 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, resulting in a poor heat dissipation effect of the temperature equalizing plate 021.

[0066] Based on this, an embodiment of the present application provides a liquid wick having multiple capillary structures, which are arranged to overlap each other, so that while ensuring that the liquid working medium can flow between the multiple capillary structures, the liquid wick can simultaneously take into account the requirements of liquid return rate and evaporation rate. For example, the multiple capillary structures may include a first capillary structure, a second capillary structure, and a third capillary structure. The third capillary structure is stacked with the first capillary structure and the second capillary structure in a first direction (e.g., Z direction), and the first capillary structure and the second capillary structure overlap each other in a second direction (e.g., X direction), and the second direction is perpendicular to the first direction. Among them, the first capillary structure and the third capillary structure have strong capillary forces to meet the requirements for liquid return rate. The second capillary structure has a high porosity to meet the requirements for evaporation rate. In this way, after the liquid wick is assembled on the electronic device as part of the heat spreader, the second capillary structure serves as the evaporation end of the heat spreader, which can increase the evaporation rate of the evaporation end, and under the strong capillary forces of the first capillary structure and the third capillary structure, the rapid liquid return of the working medium can be ensured.

[0067] It is understood that structures obtained by processing metal materials using different processes can have different capillary forces and porosities. Therefore, the first and second capillary structures can respectively utilize metal structures obtained by different processes. For example, the first and third capillary structures can utilize metal mesh or sintered metal powder to ensure strong capillary forces, while the second capillary structure can utilize preformed metal foam or be manufactured by electrodeposition to ensure high porosity.

[0068] The first embodiment of the absorbent core of the present application will be described in detail below with reference to FIG. 3 to FIG. 11B .

[0069] First, please refer to Figure 3, which shows a schematic structural diagram of a temperature averaging plate 10 using the liquid wick of this embodiment. It should be noted that Figure 3 is a cross-sectional view of the temperature averaging plate 10 along the XZ plane.

[0070] As shown in Figure 3, the temperature distribution board 10 includes a wick 11 and a housing 12. The housing 12 is a sealed shell with a "square" cross-section. The interior of the housing 12 is a sealed cavity 10a. The wick 11 is arranged on the inner wall of the housing 12 and is filled with a liquid working medium.

[0071] As can be seen from Figure 2 , the flow fields of the working fluid in vapor chamber 10 and vapor chamber 021 differ. In vapor chamber 021, the working fluid circulates through phase change from one end to the other to dissipate heat, while in vapor chamber 10, the working fluid circulates through phase change from the center to the ends to dissipate heat. In other words, vapor chamber 10 has both ends along the X-axis as the condensing end, and the center as the evaporating end.

[0072] For ease of explanation, this application divides the temperature equalizing plate 10 into a heat source area and a heat dissipation area based on the steam flow direction in the temperature equalizing plate 10. Please refer to Figures 4A and 4B. Figures 4A and 4B are schematic diagrams of the projections of some possible temperature equalizing plates 10 on the XY plane, wherein the Y direction is perpendicular to the X direction and the Z direction, respectively. For example, as shown in Figure 4A, the projection area of ​​the temperature equalizing plate 10 on the XY plane is a rectangular area A. Referring to the steam flow direction indicated by the arrow, the central shaded area of ​​the rectangular area A can be the heat source area A1, and the annular area surrounding the central shaded area can be the heat dissipation area A2. Alternatively, as shown in Figure 4B, the projection area of ​​the temperature equalizing plate 10 on the XY plane is a rectangular area A. Referring to the steam flow direction indicated by the arrow, the middle shaded area of ​​the rectangular area A can be the heat source area A1, and the areas on both sides can be the heat dissipation areas A2. It can be understood that in other embodiments, the temperature equalizing plate 10 can have different division areas of the heat source area and the heat dissipation area, and this application does not limit this.

[0073] Continuing with FIG3 , the wick 11 includes a first capillary structure 111, a second capillary structure 112, and a third capillary structure 113. The third capillary structure 113 is stacked with the first capillary structure 111 and the second capillary structure 112 in the Z direction, respectively. The first capillary structure 111 and the second capillary structure 112 overlap in the X direction. The overlapping of the first capillary structure 111 and the second capillary structure 112 in the X direction may 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 portions of the first capillary structure 111 and the second capillary structure 112 overlap in the Z direction. Furthermore, the first capillary structure 111 is located in the heat dissipation area A2. The overlapping portion of the second capillary structure 112 with the first capillary structure 111 is located in the heat dissipation area A2, and the remaining portion is located in the heat source area A1. Part of the third capillary structure 113 is located in the heat source area A1, and part is located in the heat dissipation area A2.

[0074] In some embodiments, the size of the third capillary structure 113 in the X direction is larger than the size of the second capillary structure 112 in the X direction. Thus, the portion of the third capillary structure 113 located in the heat source area A1 can be used together with the second capillary structure 112 to accelerate the evaporation of the liquid working medium, and the portion of the third capillary structure 113 located in the heat dissipation area A2 can be used together with the first capillary structure 111 to accelerate the backflow of the liquid working medium.

[0075] The positional relationship between the first capillary structure 111 and the second capillary structure 112 can be seen with reference to FIG4A or FIG4B . FIG4A and FIG4B are two schematic cross-sectional views of the wick 11 along the M-M' direction shown in FIG3 . 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 area, and the second capillary structure 112 is arranged in this hollow area. The projected area of ​​the third capillary structure 113 on the XY plane covers the heat source area A1 and at least a portion of the heat dissipation area A2. In some embodiments, the projected area of ​​the third capillary structure 113 on the XY plane can cover the projected areas of the first capillary structure 111 and the second capillary structure 112 on the XY plane. The structures of the first capillary structure 111, the second capillary structure 112, and the third capillary structure 113 and their overlapping methods will be further described below and will not be repeated here.

[0076] In some embodiments, the first capillary structure 111 has a strong capillary force to facilitate liquid reflux. Exemplarily, the first capillary structure 111 is a metal mesh structure, or a sintered metal powder structure. Specifically, the materials of the metal mesh and metal powder / powder strips mentioned in this application include, but are not limited to, materials with high thermal conductivity, such as copper and aluminum.

[0077] In some embodiments, the pore size of the second capillary structure 112 adopts a bimodal design. That is, it can be clearly seen from the pore size distribution curve of the second capillary structure 112 that the second capillary structure 112 has two pore sizes with a large distribution number, and these two pore sizes are different in size, which can respectively meet the requirements of higher capillary force and higher porosity. Exemplarily, the second capillary structure 112 can adopt preformed foam metal, or be formed by electroplating metal. Exemplarily, Figure 5 is a schematic diagram of the internal structure of a second capillary structure 112 using foam metal. As can be seen from Figure 5, pores of different sizes are distributed in the foam metal. In this way, the second capillary structure 112 can simultaneously have a strong capillary force to allow the working medium to quickly reflux, and can achieve rapid evaporation of heat, thereby improving the maximum heat dissipation capacity of the temperature dispersion plate 10.

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

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

[0080] In this way, the wick 11 can combine the advantages of different capillary structures through overlapping coupling of different capillary structures, achieve the best capillary force, minimum liquid flow resistance, and minimum vapor flow resistance design, so that the performance of the temperature equalizer 10 reaches the best.

[0081] Experimental verification of electronic devices using the vapor chamber 10 in actual applications shows that the vapor chamber 10, including the wick 11, improves both the junction temperature gain of the heat source and the transient Turbo performance of the entire device. Specifically, the junction temperature gain can be increased 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 0.58 mm to 0.62 mm. The thickness of the first capillary structure 111 and the second capillary structure 112 in the Z direction is 0.18 mm to 0.22 mm, and the thickness of the third capillary structure 113 in the Z direction is 0.38 mm to 0.42 mm. For example, the thickness of the wick 11 in the Z direction is 0.6 mm. The thickness of the first capillary structure 111 and the second capillary structure 112 in the Z direction is 0.2 mm, and the thickness of the third capillary structure 113 in the Z direction is 0.4 mm.

[0083] It should be noted that the present application does not limit the shapes of the first capillary structure 111, the second capillary structure 112 and the third capillary structure 113. 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 the convenience of description, this article and each figure use the example that the projection shape of the first capillary structure 111 on the XY plane is a "square", the projection shape of the second capillary structure 112 is a rectangle, and the projection shape of the third capillary structure 113 is a rectangle.

[0084] As mentioned above, the first capillary structure 111 and the second capillary structure 112 overlap each other in the X direction. Please refer to Figures 6A and 6B, which respectively illustrate different overlapping methods 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 each other not only in the X direction, but also in the Y direction. It is understood that the first capillary structure 111 is arranged around the second capillary structure 112. Therefore, the overlapping area between the first capillary structure 111 and the second capillary structure 112 can be in the shape of a "square". Specifically, the first capillary structure 111 and the second capillary structure 112 have a first overlapping area 11-1 and a second overlapping area 11-2 in the X direction, and the first capillary structure 111 and the second capillary structure 112 have a third overlapping area 11-3 and a fourth overlapping area 11-4 in the Y direction. The first overlapping area 11-1, the second overlapping area 11-2, the third overlapping area 11-3, and the fourth overlapping area 11-4 correspond to the four sides of the "square" respectively.

[0086] It can be understood that by setting the overlapping area between the first capillary structure 111 and the second capillary structure 112, it can be ensured that no gap is left between the first capillary structure 111 and the second capillary structure 112, so that the liquid working medium can flow back smoothly from the first capillary structure 111 to the second capillary structure 112, reducing the liquid reflux flow resistance.

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

[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 can be understood that in any overlapping region 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] Several different overlapping structures are described below using the first overlapping region 11 - 1 and the second overlapping region 11 - 2 in the X direction as examples. Please refer to Figure 7 , which shows several cross-sectional views along the BB′ direction in Figure 6A .

[0091] As shown in (a) and (c) of Figure 7 , the first capillary structure 111 overlaps the second capillary structure 112. As shown in (b) and (d) of Figure 7 , the second capillary structure 112 overlaps the first capillary structure 111. In general, the overlapping portion 111-1 of the first capillary structure 111 located in the first overlapping region 11-1 and the overlapping portion 112-1 of the second capillary structure 112 located in the first overlapping region 11-1 are stacked together along the Z direction.

[0092] 7 (a) and (b), 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] 7 (c) and (d), 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 area 11 - 2 is similar and will not be described in detail.

[0095] In the above embodiment, referring to Figures 6A and 6B, each overlapping region has a continuous pattern, that is, the first capillary structure 111 and the second capillary structure 112 in the overlapping region are continuous physical structures. In other embodiments, at least one overlapping region may also have a hollow pattern, that is, the first capillary structure 111 or the second capillary structure 112 in the overlapping region may be a discontinuous physical structure. For example, refer to Figure 8, which shows a schematic diagram of an overlapping region with a hollow pattern. It should be noted that the hollow pattern may include, but is not limited to, the rectangle shown in the figure, and may also be a regular or irregular shape such as a circle or triangle.

[0096] As shown in FIG8 , the first overlapping area 11 - 1 to the fourth overlapping area 11 - 4 all have rectangular hollow patterns, and each overlapping area is in the shape of a “Great Wall sawtooth”.

[0097] Figure 9 is two cross-sectional views taken along the C-C' direction in Figure 8. As shown in (a) in Figure 9, in the fourth overlapping region 11-4, the second capillary structure 112 overlaps the first capillary structure 111. The second capillary structure 112 is located in the overlapping portion (an example of the second overlapping portion) of the fourth overlapping region 11-4 and includes a plurality of sub-portions 1121 (an example of the second sub-portion) spaced apart, with three sub-portions 1121 being used as an example in the figure. It will be understood that the first capillary structure 111 is filled between adjacent sub-portions 1121. Therefore, the first capillary structure 111 is located in the overlapping portion (an example of the first overlapping portion) of the fourth overlapping region 11-4 and also includes a plurality of sub-portions 1111 (an example of the first sub-portion) spaced apart, with two sub-portions 1111 being used as an example in the figure.

[0098] As shown in (b) of Figure 9, in the fourth overlapping area 11-4, the first capillary structure 112 overlaps the first capillary structure 111. The first capillary structure 111 is located in the overlapping portion of the fourth overlapping area 11-4 (an example of the first overlapping portion), including a plurality of spaced sub-portions 1111 (an example of the first sub-portion), with three sub-portions 1111 being used as an example in the figure. It can be understood that the second capillary structure 112 is filled between adjacent sub-portions 111. Therefore, the second capillary structure 112 is located in the overlapping portion of the fourth overlapping area 11-4 (an example of the second overlapping portion), and also includes a plurality of spaced sub-portions 1121 (an example of the second sub-portion), with two sub-portions 1121 being used as an example in the figure.

[0099] As can be seen from FIG. 9 , the multiple sub-portions 1121 of the second capillary structure 112 located in the fourth overlapping region are alternately arranged with the multiple sub-portions 1111 of the first capillary structure 111 located in the fourth overlapping region.

[0100] The advantage of adopting the hollow design is that it can reduce the area of ​​the overlapping region between the first capillary structure 111 and the second capillary structure 112, which helps to reduce the liquid reflux flow resistance and the steam flow resistance.

[0101] Continuing with FIG6A , the dimension x1 of the first overlapping region 11-1 in the X direction, the dimension x2 of the second overlapping region 11-2 in the X direction, the dimension y3 of the third overlapping region 11-3 in the Y direction, and the dimension y4 of the fourth overlapping region 11-4 in the Y direction may or may not be completely identical. For example, as shown in FIG6B , the dimension x1 of the first overlapping region 11-1 in the X direction may be equal to the dimension x2 of the second overlapping region 11-2 in the X direction, and both may be greater than the dimension y4 of the fourth overlapping region 11-4 in the Y direction.

[0102] 10A and 10B , which respectively illustrate the relative positions of the vapor chamber 10 and the heat source (e.g., a CPU) 100 at different viewing angles. As shown in FIG10A , the housing 12 includes a first cover plate 121 and a second cover plate 122 along the Z direction. 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. The second cover plate 122 is in contact with the CPU 100, which is positioned below the second capillary structure 112.

[0103] As shown in FIG10A , the surface of the second capillary structure 112 in contact with the second cover plate 122 along the Z direction is the first heat source surface 112a, and the surface away from the second cover plate 122 is the second heat source surface 112b. The dimensions of the first heat source surface 112a and / or the second heat source surface 112b are greater than or equal to the dimensions of the CPU 100. For example, along the X direction, the dimension x112a of the first heat source surface 112a and the dimension x112b of the second heat source surface 112b are both greater than the dimension x100 of the CPU. Thus, because the CPU and the vapor chamber 10 have a sufficiently large contact area, it is possible to ensure that all heat from the CPU surface can enter the vapor chamber 10 via the first heat source surface 11a, thereby achieving heat dissipation.

[0104] As shown in FIG10B , 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 larger 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 larger 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, on the XY plane, the projections of the first heat source surface 112a and the second heat source surface 112b overlap the projection of the CPU 100.

[0105] Figures 11A and 11B show another schematic diagram of the relative position between the heat spreader 10 and the CPU 100. The structure of the heat spreader 10 shown in Figure 11A is the same as that of the heat spreader 10 shown in Figure 10A. Therefore, regarding the dimensions of the first heat source surface and the second heat source surface of the second capillary structure 112, reference can be made to the relevant embodiment of Figure 10A. The only difference from Figures 10A and 10B is that in this example, the CPU 100 is located below the overlapping area 11-1 between the first capillary structure 111 and the second capillary structure 112. That is, referring to Figure 11B, if the size of the CPU 100 in the X direction is larger than the size of the overlapping area 11-1, then on 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 temperature 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 is described below in conjunction with Figure 12. As shown in Figure 12 (a), first, metal powder is sintered on the second cover plate 122 to form a first capillary structure 111. It is understandable that in other embodiments, the preparation of the wick 11 can also be completed on other substrates first, and then the entirety is transferred to the second cover plate 122 and sintered with the second cover plate 122. As shown in Figure 12 (b), the first capillary structure 111 is grooved to form a groove 111a. The cross-section of the groove 111a can be in the shape of an "inverted convex character", or it can be in the shape of a "positive convex character" or a rectangle as shown in other figures in Figure 7, depending on the structural design of the actual overlap area. As shown in Figure 12 (c), a preformed foam metal is used to fill the groove 111a, or a metal is directly electroplated in the groove 111a to form a second capillary structure 112. Next, as shown in FIG. 12 ( d ), metal powder is sintered on the surfaces of the first capillary structure 111 and the second capillary structure 112 to form a third capillary structure 113 , thereby obtaining the liquid absorbent core 11 .

[0108] In this embodiment, the wick 11 can combine the advantages of different capillary structures through overlapping coupling of different capillary structures, achieve optimal capillary force, minimum liquid flow resistance, and minimum steam flow resistance design, and optimize the performance of the temperature equalizing plate 10.

[0109] 13 and 14 , the second embodiment of the absorbent core of the present application will be described in detail.

[0110] Please refer to Figure 13, which shows a schematic diagram of the structure of a heat spreader 20 employing the liquid wick of this embodiment. As shown in Figure 13, heat spreader 20 comprises a liquid wick 21 and a housing 22. The liquid wick 21 is mounted on the inner wall of the housing 22 and is filled with a liquid medium. The interior of the housing 22 defines a sealed cavity 20a. The structure of the housing 22 is identical to that of the housing 21, and reference can be made to the various embodiments of the housing 21, and will not be further described in this embodiment.

[0111] Vapor chamber 20 differs from vapor chamber 10 in that the working fluid in vapor chamber 20 circulates through phase change from one end to the other to dissipate heat. That is, one end of vapor chamber 20 along the X-axis is the condensing end, and the other end is the evaporating end. The flow field of the working fluid circulating in vapor chamber 20 is similar to that of vapor chamber 021.

[0112] For ease of explanation, this application divides the vapor chamber 20 into a heat source region and a condensation region based on the direction of steam flow within the vapor chamber 20. Please refer to Figure 14, which is a schematic cross-sectional view taken along the N-N' direction shown in Figure 13. For example, as shown in Figure 14, the projection of the vapor chamber 20 on the XY plane is rectangular region A. Referring to the steam flow direction indicated by the arrow, the right side of rectangular region D is the heat source region D1, and the left side is the heat dissipation region D2.

[0113] Continuing to refer to Figure 13, the wick 21 includes a first capillary structure 211, a second capillary structure 212 and a third capillary structure 213, wherein the third capillary structure 213 is stacked with the first capillary structure 211 and the second capillary structure 212 in the Z direction, and the first capillary structure 211 and the second capillary structure 212 overlap each other in the X direction. The meaning of overlapping each other can refer to the above embodiment and will not be repeated here. Specifically, the first capillary structure 211 and the second capillary structure 212 have an overlapping area 21-1 in the X direction. In addition, the first capillary structure 211 is located in the heat dissipation area D2, and the overlapping portion of the second capillary structure 212 with the first capillary structure 211 is located in the heat dissipation area D2, and the remaining portion 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 seen in Figure 14. For example, the first capillary structure 211 and the second capillary structure 212 are sequentially arranged or adjacently arranged along the X direction.

[0115] Regarding the structure, materials, overlapping method and structure of the first capillary structure 211, the second capillary structure 212 and the third capillary structure 213, reference can be made to the structure, materials, overlapping method and structure of the first capillary structure 111, the second capillary structure 112 and the third capillary structure 113 described above. For example, the overlapping area 21-1 can refer to the specific embodiment of the overlapping area 11-1, and will not be further described in this embodiment.

[0116] It can be understood that the wick 21 can be compatible with the advantages of different capillary structures through overlapping coupling of different capillary structures, and achieve the best capillary force, minimum liquid flow resistance, and minimum steam flow resistance design, so that the performance of the temperature equalizer 20 reaches the best.

[0117] It can be understood that an embodiment of the present application also provides an electronic device, which is equipped with the above-mentioned temperature averaging plate 10 or temperature averaging plate 20. The temperature averaging plate 10 or temperature averaging plate 20 can dissipate heat from heat sources in the electronic device, such as high-power devices, to ensure the normal operation of various functions of the electronic device.

[0118] In the above description of this embodiment, unless otherwise specified, " / " means or, for example, A / B can identify A or B; "and / or" in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can represent the existence of A alone, B alone, and the existence of A and B at the same time.

[0119] It should be noted that in the examples and description of the present application, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a" does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0120] While the present application has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present application.

Claims

1. A liquid-absorbing core, characterized in that: It includes 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 respectively along a first direction, the first capillary structure and the second capillary structure are overlapped with each other along a second direction, and the first direction and the second direction are perpendicular to each other; 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.

2. The absorbent core according to claim 1, wherein The first capillary structure is a metal mesh structure or a sintered metal powder structure.

3. The absorbent core according to claim 2, wherein: The second capillary structure is a preformed foam metal structure or is formed by electrodeposition of metal.

4. The absorbent core according to claim 3, wherein The pore size inside the second capillary structure is bimodal in distribution.

5. The absorbent core according to claim 3, wherein The third capillary structure is a metal mesh structure or a sintered metal powder structure.

6. The absorbent core according to any one of claims 1 to 5, characterized in that 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.

7. The absorbent core according to any one of claims 1 to 5, characterized in that A size of the third capillary structure in the second direction is greater than a size of the second capillary structure in the second direction.

8. The absorbent core according to any one of claims 1 to 5, characterized in that 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.

9. The absorbent core according to any one of claims 1 to 5, characterized in that 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 at a first overlapping portion of the overlapping region, and the second capillary structure is located at a second overlapping portion of the overlapping region, and the two structures are stacked on each other along the first direction.

10. The absorbent core according to claim 9, characterized in that The sum of the thicknesses of the first overlapping portion and the second overlapping 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.

11. The absorbent core according to claim 9, characterized in that The first overlapping portion includes a plurality of first sub-portions arranged at intervals, and the second overlapping portion includes a plurality of second sub-portions arranged at intervals, wherein the plurality of first sub-portions and the plurality of second sub-portions are arranged alternately.

12. A temperature equalizing plate, characterized in that: The invention comprises the absorbent core according to any one of claims 1 to 11 and a shell, wherein the absorbent core is arranged in the cavity of the shell.

13. An electronic device, characterized in that: The device comprises the temperature vapor chamber according to claim 12 and a power device, wherein the temperature vapor chamber is used to dissipate heat for the power device.

14. The electronic device according to claim 13, wherein: On a first plane perpendicular to the first direction, a projection of the second capillary structure in the temperature vapor chamber covers a projection of the power device.

15. The electronic device according to claim 13, wherein: On a first plane perpendicular to the first direction, a projection of the second capillary structure in the temperature vapor chamber only partially overlaps with a projection of the power device.

16. The electronic device according to any one of claims 13 to 15, characterized in that: On a first plane perpendicular to the first direction, a size of the second capillary structure is greater than or equal to a size of the power device.

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