Vapor chamber and electronic equipment

Abstract

The invention discloses a vapor chamber and electronic equipment, and belongs to the technical field of heat dissipation. The vapor chamber comprises a shell, a first capillary structure and a working medium, the first capillary structure and the working medium are both located in the shell, the area of the projection of the first capillary structure on the first inner surface of the shell is smaller than the area of the first inner surface, a cavity is formed in the shell, the working medium in the liquid state is located in the first capillary structure, and the working medium in the gas state is located in the cavity; the area in the shell comprises a first area and a second area, the first capillary structure comprises a first part located in the first area and a second part located in the second area, the second part comprises a main structure and a branch structure, the branch structure comprises at least one branch, and each branch makes contact with or is close to the main structure. By the adoption of the liquid working medium adsorption device, the liquid working medium in the second area can be adsorbed in the first capillary structure as much as possible, and it is avoided that the unabsorbed liquid working medium is frozen at the low temperature, so that the shell is swelled.

Description

Vapor chambers and electronic devices

[0001] This application claims priority to Chinese patent application No. 202310418150.3 filed on April 12, 2023, entitled “Heat Spreader and Electronic Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to the field of heat dissipation technology, and in particular to a vapor chamber and an electronic device. Background Art

[0003] Vapor chambers are widely used in electronic devices, especially high-performance and larger-capacity electronic devices, such as notebook computers, tablet computers, and servers.

[0004] As electronic devices become increasingly ultra-thin, vapor chambers must also become thinner. However, as the thickness of the vapor chamber decreases, its shell wall is prone to bulging, which affects the heat source in contact with the vapor chamber.

[0005] Summary of the Invention

[0006] The present disclosure provides a vapor chamber and an electronic device, which can solve the problem in related art that as the vapor chamber thickness decreases, its shell wall is prone to bulging. The technical solution is as follows:

[0007] In a first aspect, a vapor chamber is provided, comprising a shell, a first capillary structure, and a working medium; the first capillary structure and the working medium are both located in the shell, and an area of ​​a projection of the first capillary structure on a first inner surface of the shell is smaller than an area of ​​the first inner surface, so that a cavity can be formed in the shell; the working medium converts between a gaseous state and a liquid state, with the working medium in the liquid state located in the first capillary structure and the working medium in the gaseous state located in the cavity;

[0008] The area within the shell includes a first area and a second area, wherein the first area corresponds to the area where the heat source is located, and the second area is different from the first area. The first capillary structure includes a first part located in the first area and a second part located in the second area. The second part includes a trunk structure and a branch structure. The trunk structure is connected to the first part, and the branch structure corresponds to the area where the cold source is located and includes at least one branch. Each branch is in contact with or close to the trunk structure.

[0009] Among them, the first area corresponds to the heat source. For example, when the heat spreader dissipates heat for the heat source, the outer surface of the shell wall of the heat spreader in the first area contacts the outer surface of the heat source, so that the heat generated when the heat source is working is transferred to the shell wall located in the first area.

[0010] The second area is different from the first area. For example, the second area may be an area corresponding to a cold source. For example, the second area is an area adjacent to the cold source, and the cold source may be a fan.

[0011] The branch and the trunk structure are in contact, for example, the branch and the trunk structure are connected, the branch and the trunk structure are close, for example, the branch and the trunk structure are not connected, and the two can be parallel or non-parallel to form an angle.

[0012] In the solution disclosed herein, the second portion of the first capillary structure within the second region comprises a main structure and a branch structure, each of which includes at least one branch. This allows the liquid working fluid within the second region to be adsorbed as much as possible within the first capillary structure, preventing unabsorbed liquid working fluid from freezing at low temperatures. Once ice forms within the vapor chamber at low temperatures, the vapor chamber shell will essentially remain flat, maintaining a flat surface and preventing any interference with the heat source in contact with it.

[0013] For example, the branch structure corresponds to the area where the cold source is located. Then, the branch structure includes at least one branch, which can adsorb the liquid working medium in the area corresponding to the cold source in the first capillary structure as much as possible to prevent the unabsorbed liquid working medium from freezing at low temperatures.

[0014] In a possible implementation, each branch includes at least two sub-branches, and each sub-branch is connected to its own branch.

[0015] In the solution shown in the present disclosure, each branch can form at least two sub-branches by bifurcation. The more sub-branches and branches there are, the larger the area occupied by the first capillary structure in the second region, and the liquid working medium in the second region can be adsorbed in the first capillary structure as much as possible.

[0016] In a possible implementation manner, a capillary pore diameter of the second portion located in the second region is larger than a capillary pore diameter of the first portion located in the first region.

[0017] Among them, for the capillary structure, the smaller the capillary pore size, the greater the capillary force, and the easier it is to adsorb liquid working fluid. The smaller the capillary pore size, the greater the backflow resistance of the liquid working fluid in the capillary structure, the smaller the permeability of the capillary structure, and the less likely the liquid working fluid is to reflux.

[0018] In the solution disclosed herein, the capillary pores of the first portion are relatively small, resulting in a greater capillary force. This greater capillary force can be utilized to more easily adsorb liquid working fluid, thereby promptly replenishing the liquid working fluid in the first region. The capillary pores of the second portion are relatively large, resulting in a greater permeability. This greater permeability can be utilized to reduce the liquid return resistance of the liquid working fluid, making it easier for the liquid working fluid to flow back into the first region, thereby promptly replenishing the liquid working fluid in the first region. Once the liquid working fluid in the first region is replenished in a timely manner, the situation where there is no liquid working fluid available for evaporation in the first region can be avoided, ensuring that there is always evaporable liquid working fluid in the first region, thereby enhancing the heat dissipation effect of the heat spreader.

[0019] In a possible implementation, on the surface of the first inner surface located within the first region, a projected area of ​​the first portion is larger than a non-projected area, and the non-projected area is larger than zero.

[0020] Wherein, if the non-projected area is greater than zero, it means that the first portion does not completely occupy the surface of the first inner surface in the first region. If the non-projected area is equal to zero, it means that the first portion completely occupies the surface of the first inner surface in the first region.

[0021] In a possible implementation, a projected area of ​​the first portion on the surface of the first inner surface located within the first region is equal to an area of ​​the surface of the first portion on the first inner surface located within the first region.

[0022] The projection area of ​​the first portion on the surface of the first inner surface located within the first region is equal to the area of ​​the surface of the first portion on the first inner surface located within the first region, indicating that the non-projection area is zero.

[0023] For example, the first capillary structure is directly located on the first inner surface. Then, the area of ​​the first inner surface in the first region covered by the first portion is larger than the area not covered by the first portion.

[0024] In this way, the first part of the first capillary structure in the first region occupies a relatively large area, which can store a large amount of liquid working fluid, thereby ensuring that the liquid working fluid in the first region is always in a relatively full state, thereby avoiding the situation where there is no liquid working fluid available for evaporation in the first region, thereby enhancing the heat dissipation effect of the heat spreader.

[0025] In addition, for the surface of the first inner surface located in the first region, the projected area of ​​the first part thereon is larger than the non-projected area, so that the first part occupies a relatively large area in the first region, thereby expanding the adsorption area of ​​the first part for adsorbing liquid working fluid in the first region, and is also beneficial to increasing the liquid working fluid adsorbed by the first capillary structure in the first region.

[0026] In a possible implementation, the second region corresponds to a cold source, there are multiple second regions, and the second part is arranged in each second region.

[0027] The solution shown in the present disclosure can transfer the heat absorbed in the first area to multiple second areas for heat dissipation by circulating the working fluid in the shell, which can enhance the heat dissipation effect of the heat spreader on the heat source.

[0028] In a possible implementation, the vapor chamber includes at least two first capillary structures;

[0029] The first portions of the at least two first capillary structures are both located in the first region, and the second portion of each first capillary structure is respectively located in one of the second regions.

[0030] In the solution shown in the present disclosure, there are multiple first capillary structures, which can ensure that a second part is arranged in each second area.

[0031] In a possible implementation manner, the first portions of the at least two first capillary structures have overlapping portions in a direction parallel to the first inner surface.

[0032] For example, the first portions of the two oppositely located first capillary structures have an overlapping portion within the first region and in a direction parallel to the first inner surface.

[0033] In the solution disclosed herein, the first portions of two opposing first capillary structures overlap. This facilitates ensuring that the projected area of ​​the first capillary structures on the first inner surface within the first region is larger than the unprojected area, thereby increasing the storage capacity of the liquid working medium within the first region. Furthermore, this facilitates the arrangement of a larger number of first capillary structures within the limited space within the vapor chamber.

[0034] In a possible implementation manner, the first portions of the at least two first capillary structures are spaced apart in a direction parallel to the first inner surface.

[0035] For example, the two first portions having the overlap are close but not in contact.

[0036] In the solution shown in the present disclosure, multiple first parts located in the first area are close to each other and arranged at intervals without contacting each other, which can increase the heat dissipation area in the first area. This is because the liquid working medium generally evaporates on the outer surface of the first part, and the multiple first parts do not contact each other, which increases the area of ​​the outer surface of the first area, thereby increasing the heat dissipation area in the first area.

[0037] In a possible implementation, a gap is provided between the first capillary structure and the second inner surface of the housing, and the second inner surface is a surface opposite to the first inner surface.

[0038] In the solution shown in the present disclosure, since the thermal resistance of heat in the gap is relatively large, the heat transfer between the first capillary structure and the shell wall where the second inner surface is located is relatively weak, and the temperature on the shell wall where the second inner surface is located is not very high. Therefore, the temperature difference between the shell wall where the second inner surface is located and the outer shell of the electronic device is relatively small. As a result, the user will basically not feel the heat when in contact with the outer shell of the electronic device, thereby enhancing the user experience of using the electronic device.

[0039] In a possible implementation, the vapor chamber further includes a second capillary structure;

[0040] The second capillary structure completely covers the first inner surface. For example, the projected area of ​​the second capillary structure on the first inner surface is equal to the area of ​​the first inner surface.

[0041] The first capillary structure is located on the surface of the second capillary structure, and the working medium in a liquid state is located in the first capillary structure and the second capillary structure.

[0042] In the solution shown in the present disclosure, the first capillary structure can be in the shape of a strip, and the second capillary structure can be in the shape of a sheet. The area occupied by the second capillary structure is larger than the area occupied by the first capillary structure. Therefore, the liquid working fluid adsorbed in the second capillary structure is more than the liquid working fluid adsorbed in the first capillary structure. Moreover, the second capillary structure is closer to the heat source. Therefore, the second capillary structure can serve as the main heat dissipation structure of the heat spreader, and the first capillary structure serves as a heat dissipation structure auxiliary to the second capillary structure of the heat spreader, which can enhance the heat dissipation effect of the heat spreader.

[0043] In a possible implementation, a capillary pore diameter of a portion of the second capillary structure within the second region is larger than a capillary pore diameter of a portion within the first region.

[0044] The solution shown in the present disclosure can balance the capillary force and permeability of the second capillary structure by having the second capillary structure have a small capillary pore size in the first area and a large capillary pore size in the second area, so that the second capillary structure has a larger capillary force in the first area and a larger permeability in the second area.

[0045] In this way, the liquid working medium adsorbed by the second capillary structure in the second region can relatively easily flow back to the first region, and the liquid working medium can relatively easily be adsorbed in the first region.

[0046] In a possible implementation manner, the capillary pore diameter of the first capillary structure is different from the capillary pore diameter of the second capillary structure.

[0047] In order to further balance the capillary force and the permeability in the solution shown in the present disclosure, the capillary pore diameters of the first capillary structure and the second capillary structure may be different accordingly.

[0048] For example, the capillary pore diameter of the first capillary structure may be larger than the capillary pore diameter of the second capillary structure. For another example, the capillary pore diameter of the first capillary structure may be smaller than the capillary pore diameter of the second capillary structure.

[0049] In a possible implementation manner, the second capillary structure is made of foam metal.

[0050] The foam metal may be foam copper.

[0051] In the solution disclosed herein, the foam metal is a multi-layer stacked structure. Accordingly, as an example, the material of the first capillary structure can be foam metal (such as foam copper). During production, different pore-forming agents can be selected to achieve different capillary pore diameters at different positions of the first capillary structure. For example, when using foam metal to process the first capillary structure, a pore-forming agent with a relatively small pore diameter can be selected to process the first portion, and a pore-forming agent with a relatively large pore diameter can be selected to process the second portion. In this way, the capillary pore diameter of the first portion of the processed first capillary structure is smaller than the capillary pore diameter of the second portion.

[0052] In a possible implementation, the first capillary structure is made of foam metal (such as foam copper).

[0053] In the embodiment of the present disclosure, the material of the second capillary structure can also be foamed metal (such as foamed copper). During production, the second capillary structure can be processed into a second capillary structure having large and small capillary pores by using pore-forming agents with different pore sizes, so that the capillary pore diameter of the portion of the second capillary structure in the second region is larger than the capillary pore diameter of the portion in the first region.

[0054] In a possible implementation manner, the first capillary structure is a multi-layer stacked structure.

[0055] In a possible implementation, the second capillary structure is a multi-layer stacked structure.

[0056] In a possible implementation, the multi-layer stacking structure is a preformed multi-layer stacking structure.

[0057] In the solution shown in the present disclosure, preforming is to pre-process the multi-layer stacked structure before processing the heat spreader, and then cut it into the required shape based on the size of the heat spreader.

[0058] In a possible implementation, the multi-layer stacked structure is processed by one of calendering, silk screen printing, 3D printing and electroplating.

[0059] In a second aspect, a vapor chamber is further provided, comprising a shell, a first capillary structure, a working medium, and a third capillary structure; the first capillary structure, the working medium, and the third capillary structure are all located in the shell, and an area of ​​a projection of the first capillary structure on a first inner surface of the shell is smaller than an area of ​​the first inner surface; a cavity is defined within the shell, the working medium transitions between a gaseous state and a liquid state, and the working medium in the liquid state is located in the first capillary structure and the third capillary structure, while the working medium in the gaseous state is located in the cavity;

[0060] The area within the shell includes a first area and a second area, the first area corresponds to the area where the heat source is located, and the second area is different from the first area. The first capillary structure includes a first part and a second part, the first part is located in the first area, the second part and the third capillary structure are both located in the second area, and the second part and the third capillary structure are in contact or close to each other.

[0061] The solution disclosed herein comprises not only the second portion of the first capillary structure but also a third capillary structure within the second region. The capillary structure occupies a larger area within the second region, thereby maximizing the absorption of liquid within the second region into the first capillary structure and preventing unabsorbed liquid from freezing at low temperatures. Once ice forms within the vapor chamber at low temperatures, the vapor chamber shell remains substantially free of bulging, maintaining a flat surface and preventing any interference with the heat source in contact with it.

[0062] In a possible implementation, the vapor chamber further includes a second capillary structure;

[0063] The second capillary structure completely covers the first inner surface, the first capillary structure and the third capillary structure are both located on the surface of the second capillary structure, and the liquid working medium is located in the first capillary structure, the second capillary structure and the third capillary structure.

[0064] In the solution shown in the present disclosure, the first capillary structure and the third capillary structure can be in the form of strips, and the second capillary structure can be in the form of sheets. The area occupied by the second capillary structure is larger than the sum of the areas occupied by the first capillary structure and the third capillary structure. Therefore, the liquid working fluid adsorbed in the second capillary structure is larger than the liquid working fluid adsorbed in the first capillary structure and the third capillary structure. Moreover, the second capillary structure is closer to the heat source. Therefore, the second capillary structure can serve as the main heat dissipation structure of the heat spreader, while the first capillary structure and the third capillary structure serve as heat dissipation structures auxiliary to the second capillary structure of the heat spreader, thereby enhancing the heat dissipation effect of the heat spreader.

[0065] In a third aspect, an electronic device is also provided, comprising a heat source and the heat spreader described in the first aspect or the second aspect, wherein the first shell wall of the heat spreader contacts the heat source at a position corresponding to the first area, and the first shell wall is the shell wall corresponding to the first inner surface.

[0066] The shell wall corresponding to the first inner surface may be, for example, the shell wall where the first inner surface is located.

[0067] As described above, the first capillary structure of the electronic device's vapor chamber, within the second region, comprises a main structure and a branch structure, each of which includes at least one branch. This allows the liquid working medium within the second region to be absorbed by the first capillary structure as much as possible, preventing unabsorbed liquid working medium from freezing at low temperatures. If ice forms within the vapor chamber at low temperatures, the vapor chamber's housing will remain substantially free of bulging, maintaining a flat surface and preventing any interference with the heat source in contact with the vapor chamber.

[0068] For example, the branch structure corresponds to the area where the cold source is located. Then, the branch structure includes at least one branch, which can adsorb the liquid working medium in the area corresponding to the cold source in the first capillary structure as much as possible to prevent the unabsorbed liquid working medium from freezing at low temperatures.

[0069] In addition, since the second part of the first capillary structure in the second region includes a trunk structure and a branch structure, and the branch structure includes at least one branch, the area occupied by the first capillary structure in the second region can be increased, and the adsorption range of the first capillary structure in the second region for adsorbing liquid working fluid can be increased, thereby adsorbing liquid working fluid at more positions or even all positions in the second region, which will further reduce or even eliminate the unadsorbed liquid working fluid in the second region.

[0070] In addition, the first capillary structure absorbs a large amount of liquid working fluid in the second area, so the liquid working fluid can be replenished to the first area in time to avoid the situation where there is no liquid working fluid available for evaporation in the first area, so that the first area always maintains evaporable liquid working fluid, thereby improving the heat dissipation effect of the heat spreader. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] FIG1 is a schematic structural diagram of a cross section of a vapor chamber provided by the present disclosure along the thickness direction;

[0072] FIG2 is a schematic diagram of a top view of a vapor chamber provided by the present disclosure;

[0073] FIG3 is a schematic structural diagram of a first capillary structure provided by the present disclosure located in a housing;

[0074] FIG4 is a schematic diagram showing the relationship between the main structure and branches of the second part of a first capillary structure provided by the present disclosure;

[0075] FIG5 is a schematic diagram showing the relationship between the main structure and branches of the second part of a first capillary structure provided by the present disclosure;

[0076] FIG6 is a schematic diagram showing the relationship between the main structure and branches of the second part of a first capillary structure provided by the present disclosure;

[0077] FIG7 is a schematic diagram showing the relationship between the main structure and branches of the second part of a first capillary structure provided by the present disclosure;

[0078] FIG8 is a schematic diagram showing the relationship between the main structure and branches of the second part of a first capillary structure provided by the present disclosure;

[0079] FIG9 is a schematic structural diagram of a first capillary structure provided by the present disclosure located in a housing;

[0080] FIG10 is a schematic structural diagram of a first capillary structure and a second capillary structure provided by the present disclosure located in a housing;

[0081] FIG11 is a schematic structural diagram of a cross section of a vapor chamber provided by the present disclosure along the thickness direction;

[0082] FIG12 is a schematic structural diagram of a first capillary structure, a third capillary structure, and a second capillary structure provided by the present disclosure, located in a shell.

[0083] Explanation of the accompanying drawings: 1. Shell; 10. Cavity; 11. First area; 12. Second area; 13. Upper cover; 14. Base; 2. First capillary structure; 21. First part; 22. Second part; 221. Main structure; 222. Branch structure; 223. Branch; 224. Sub-branch; 3. Second capillary structure; 4. Third capillary structure. DETAILED DESCRIPTION

[0084] Although the description of the present disclosure will be introduced in conjunction with some embodiments, this does not mean that the features of this application are limited to the embodiments. On the contrary, the purpose of introducing the application in conjunction with the embodiments is to cover other options or modifications that may be extended based on the claims of the present disclosure. In order to provide an in-depth understanding of the present disclosure, the following description will contain many specific details. The present disclosure can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present disclosure, some specific details will be omitted in the description. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other unless there is a conflict.

[0085] This embodiment provides a vapor chamber (VC), which is also called a temperature equalizing plate, and mainly includes a shell, a capillary structure and a working medium. The shell includes an upper cover and a base, and the two are fixed to form a closed vacuum chamber. The capillary structure and the working medium are both located in the vacuum chamber.

[0086] The capillary structure is a microstructure with capillary phenomena, which include the phenomenon that the wetting liquid rises in the capillary tube and the phenomenon that the non-wetting liquid falls in the capillary tube.

[0087] The working medium may be water, for example.

[0088] In the vacuum chamber of the shell, the temperature at which the working medium undergoes phase change is relatively low. For example, the liquid working medium can evaporate at a relatively low temperature and transform into a gaseous working medium. The gaseous working medium condenses when cooled and transforms into a liquid working medium.

[0089] The capillary structure absorbs the liquid working medium therein by means of the capillary phenomenon, while the capillary structure does not completely occupy the vacuum chamber, so that there is a cavity in the vacuum chamber, and the gaseous working medium can flow in the cavity.

[0090] Based on the above-mentioned structural features of the heat spreader, the principle of the heat spreader to dissipate heat for the heat source may be that the first area of ​​the heat spreader is in contact with the heat source. When the heat source is working, a large amount of heat is generated. The heat is transferred from the heat source to the first area of ​​the heat spreader, causing the liquid working fluid in the capillary structure to evaporate due to the heat and turn into a gaseous working fluid. This phase change process can absorb a large amount of heat to dissipate heat for the heat source. Since the liquid working fluid evaporates in this first area, it can be called an evaporation zone.

[0091] The gaseous working fluid generated in the first area of ​​the heat spreader flows in the cavity. When the gaseous working fluid flows to the relatively cold second area, it will condense into liquid in the second area. This phase change process releases heat, and the heat absorbed in the first area is released in the second area. Since the liquid working fluid condenses in the second area, it can be called the condensation area.

[0092] The liquid working medium generated in the second area of ​​the vapor chamber is adsorbed in the capillary structure and flows back to the first area through the capillary phenomenon of the capillary structure.

[0093] The above process is repeated in the heat sink to dissipate heat from the heat source.

[0094] Among them, heat sinks are widely used in electronic devices, such as mobile phones, laptops, and tablet computers, to dissipate heat from heat sources in electronic devices, for example, to dissipate heat from chips in electronic devices.

[0095] As electronic devices develop towards ultra-thinness, vapor chambers are also developing towards ultra-thinness. However, the thinning of vapor chambers will at least face the following problems:

[0096] First, the cross-section of the capillary structure becomes smaller, which increases the resistance to the liquid working medium flowing back from the second area to the first area, causing a large amount of liquid working medium to accumulate in the second area, making the capillary structure in the second area in a supersaturated state. There will be liquid working medium in the second area that is not absorbed by the capillary structure. These liquid working mediums will freeze under low temperature conditions, such as in winter when the temperature is low. Compared with liquid working medium, the solid working medium has a larger volume, and the space of the vacuum chamber of the heat spreader is smaller, which will cause bulging on the outer surface of the heat spreader. The outer surface of the heat spreader is in contact with the heat source, and the bulging on the outer surface of the heat spreader may damage the heat source.

[0097] Secondly, since a large amount of liquid working fluid accumulates in the second area, less liquid working fluid will flow back into the first area, and there is a possibility that the liquid working fluid in the first area will be completely evaporated, resulting in the interruption of the working fluid circulation in the vacuum chamber and the reduction of the heat dissipation effect of the heat spreader.

[0098] The vapor chamber shown in this embodiment can improve the phenomenon of the liquid working medium gathering in the second region and improve the heat dissipation effect of the vapor chamber.

[0099] As shown in Figure 1, the vapor chamber includes a housing 1, a first capillary structure 2, and a working medium, both of which are located within the housing 1. The structure of the housing 1, as shown in Figure 1, includes an upper cover 13 and a base 14. The upper cover 13 covers the sidewalls of the base 14 to form a sealed chamber, which is then evacuated to form a vacuum chamber.

[0100] To form a cavity in the housing 1 for the flow of the gaseous working medium, as shown in FIG1 , the projection area of ​​the first capillary structure 2 on the first inner surface a of the housing 1 is smaller than the area of ​​the first inner surface a. The first inner surface a can be the inner surface of a wall of the housing 1, for example, the inner surface of the upper cover 13 or the inner surface of the base 14. As shown in FIG1 , the inner surface of the base 14 can be referred to as the first inner surface a, and the inner surface of the upper cover 13 can be referred to as the second inner surface b.

[0101] In this way, since the area of ​​the orthographic projection of the first capillary structure 2 on the first inner surface a is smaller than the area of ​​the first inner surface a, a cavity 10 can be formed between the outer surface of the first capillary structure 2 and the inner surface of the shell 1, and the gaseous working medium can flow in the cavity 10.

[0102] Furthermore, the working medium undergoes a transition between gaseous and liquid states within the housing 1, and both gaseous and liquid working mediums can coexist within the housing 1. The working medium in the liquid state can be located within the first capillary structure 2, for example, flowing within the first capillary structure 2 by means of capillary forces. The working medium in the gaseous state can be located within the cavity 10, for example, flowing within the cavity 10.

[0103] 2 , the area within the housing 1 may include a first area 11 and a second area 12, wherein the first area 11 corresponds to the area where the heat source is located, and the second area 12 is an area different from the first area 11. FIG2 is a schematic diagram of a top view of the vapor chamber.

[0104] For example, the second region 12 may be a region corresponding to a cold source, or in another example, the second region 12 may be a region other than the first region 11. For ease of description, the second region 12 may be taken as a region corresponding to a cold source.

[0105] It should be noted that the first region 11 of the vapor chamber corresponding to the heat source means that, during use, the first region 11 of the vapor chamber is positioned opposite the heat source. For example, the outer surface of the vapor chamber, at the position corresponding to the first region 11, is in close contact with the outer surface of the heat source. The second region 12 of the vapor chamber corresponding to the heat source can be positioned adjacent to the heat source, such as a fan, during use.

[0106] In order to use the first capillary structure 2 to reflux the liquid working medium in the second region 12 into the first region 11, the first capillary structure 2 accordingly includes a first part 21 and a second part 22, wherein the first part 21 is located in the first region 11, and the second part 22 is located in the second region 12. The first part 21 and the second part 22 are connected. In this way, the second part 22 located in the second region 12 can reflux the adsorbed liquid working medium into the first part 21 located in the first region 11.

[0107] To maximize the adsorption of the liquid working medium within the second region 12 within the first capillary structure 2, the second portion 22 of the first capillary structure 2 located within the second region 12 may include a trunk structure 221 and branch structures 222, as shown in FIG3 . As described above, the second region 12 may correspond to the region where the heat sink is located, and thus, the trunk structure 221 and branch structures 222 may correspond to the region where the heat sink is located.

[0108] Since a larger portion of the first capillary structure 2 is located in the second region 12 , the liquid working medium in the second region 12 can be absorbed into the first capillary structure 2 as much as possible, thereby preventing the unabsorbed liquid working medium from freezing at low temperatures.

[0109] In addition, since more parts of the first capillary structure 2 are located in the second region 12, the occupied area of ​​the first capillary structure 2 in the second region 12 can be increased, and the adsorption range of the liquid working medium adsorbed by the first capillary structure 2 in the second region 12 is increased, thereby being able to adsorb liquid working medium at more positions in the second region 12, which will further reduce the liquid working medium that is not adsorbed in the second region 12.

[0110] In addition, the first capillary structure 2 absorbs a large amount of liquid working medium in the second area 12, so the liquid working medium can be replenished to the first area 11 in time to avoid the situation where there is no liquid working medium available for evaporation in the first area 11, thereby improving the heat dissipation effect of the heat sink.

[0111] In order to enable the main structure 221 and the branch structure 222 located in the second area 12 to absorb the adsorbed liquid working medium to flow back to the first part 21 located in the first area 11, the main structure 221 is connected to the first part 21, and the liquid working medium absorbed by the branch structure 222 can flow into the main structure 221. In this way, the liquid working medium absorbed by the main structure 221 can flow into the first part 21.

[0112] In order to ensure that the liquid working medium adsorbed by the branch structure 222 can flow back into the main structure 221, one method may be to place the branch structure 222 in contact with the main structure 221, as shown in FIG3 . Another method may be to place the branch structure 222 in close proximity to the main structure 221, as shown in FIG4 , so that part or all of the branch structure 222 is within the adsorption range of the main structure 221, thereby facilitating the main structure 221 to adsorb the liquid in the branch structure 222.

[0113] Among them, the branch structure 222 is in contact with the main structure 221, that is, the branch structure 222 is connected to the main structure 221, and the branch structure 222 is close to the main structure 221, that is, the branch structure 222 is not connected to the main structure 221, and there is a gap between the two. For example, the strip-shaped branch structure 222 and the strip-shaped main structure 221 can be parallel, or they can have an angle as shown in Figure 4.

[0114] Regarding the proximity of the branch structure 222 to the main structure 221, for example, as shown in Figure 4, the branch structure 222 is at position A, which is closest to the main structure 221, satisfying that position A of the branch structure 222 is within the adsorption range of the main structure 221, so that the liquid working fluid adsorbed by the branch structure 222 can be adsorbed by the main structure 221.

[0115] In one example, the branch structure 222 includes at least one branch. For example, as shown in FIG3 , the branch structure 222 includes one branch 223. For another example, as shown in FIG4 through FIG6 , the branch structure 222 includes two branches 223. For another example, as shown in FIG7 and FIG8 , the branch structure 222 includes more than two branches 223. As shown in FIG3 through FIG8 , each branch 223 is in contact with or close to the main structure 221.

[0116] As an example, as shown in FIG3 , the branch structure 222 includes one branch, wherein the main structure 221 and the branch structure 222 may be strip-shaped and may be located side by side in the second region 12. For example, the main structure 221 and the branch structure 222 may be arranged side by side along the width direction of the main structure 221. The main portion 221 and the branch structure 222 may be in contact with each other or may have a gap therebetween.

[0117] As an example, as shown in FIG5 and FIG6 , the main structure 221 is in a strip shape, and the branches 223 of the branch structure 222 may be formed by the main structure 221 bifurcating at least once near its end.

[0118] For example, as shown in Figure 5 , the main structure 221 bifurcates once near the end to form two branches 223. For another example, as shown in Figure 6 , the main structure 221 bifurcates once near the end to form two branches 223, and each branch 223 bifurcates once more to form two sub-branches 224.

[0119] Therefore, the branch 223 may include at least two sub-branches 224, and each sub-branch 224 and its corresponding branch 223 may be connected or close to each other.

[0120] As an example, as shown in FIG. 7 and FIG. 8 , the main structure 221 is in a strip shape, and at least one branch 223 of the branch structure 222 may be located at a side portion of the main structure 221 along the width direction.

[0121] For example, as shown in FIG7 , a plurality of branches 223 may be arranged on one side of the trunk structure 221 along the width direction, and these plurality of branches 223 may not contact each other. For another example, as shown in FIG7 , a plurality of branches 223 may be arranged on both the first and second sides of the trunk structure 221 along the width direction. For another example, as shown in FIG8 , a plurality of branches 223 may be arranged on the sides of the trunk structure 221 along the width direction, and the branches 223 on the same side may contact each other.

[0122] In this embodiment, the formation method of at least one branch 223 of the branch structure 222 and its positional relationship relative to the main structure 221 are not specifically limited.

[0123] In one example, the parameters that affect the flow of the liquid working medium in the first capillary structure 2 mainly include the capillary force and permeability of the first capillary structure 2. The greater the capillary force, the better the adsorption effect of the first capillary structure 2, and the easier it is to adsorb the liquid working medium therein; the higher the permeability, the smaller the backflow resistance of the liquid working medium in the first capillary structure 2, and the easier it is to flow back into the first region 11.

[0124] The capillary force and the permeability are both related to the capillary pore size of the first capillary structure 2 . For example, the smaller the capillary pore size, the greater the capillary force, but the lower the permeability.

[0125] Therefore, in order to balance the capillary force and permeability of the first capillary structure 2, the capillary pore size of the first portion 21 of the first capillary structure 2 in the first region 11 can be relatively small to increase the capillary force, while the capillary pore size of the second portion 22 in the second region 12 can be relatively large to increase the permeability.

[0126] Accordingly, the capillary pore diameter of the second portion 22 of the first capillary structure 2 may be larger than the capillary pore diameter of the first portion 21 .

[0127] In this way, the first portion 21 utilizes its greater capillary force to more easily absorb liquid working medium, thereby timely replenishing the liquid working medium in the first region 11. The second portion 22 utilizes its greater permeability to reduce the liquid return resistance of the liquid working medium, making it easier for the liquid working medium to flow back into the first region 11, thereby timely replenishing the liquid working medium in the first region 11. Once the liquid working medium in the first region 11 is replenished in a timely manner, it can avoid the situation where there is no liquid working medium available for evaporation in the first region 11. Therefore, there is always evaporable liquid working medium in the first region 11, thereby enhancing the heat dissipation effect of the heat sink.

[0128] In one example, for a solution in which the first region 11 corresponds to a heat source and the second region 12 corresponds to a cold source, there will be a transition region between the first region 11 and the second region 12. The transition region can also be called an insulating region. Then, a portion of the first capillary structure 2 will also be located in the transition region. The capillary pore size of the third portion of the first capillary structure 2 in the transition region can also be relatively large to increase the permeability, reduce the return resistance of the liquid working fluid, and replenish the liquid working fluid to the first region 11 in a timely manner.

[0129] For example, the capillary pore diameter of the first capillary structure 2 in the transition region may be equal to the capillary pore diameter of the second portion 22 in the second region 12 , and both are larger than the capillary pore diameter of the first portion 21 in the first region 11 .

[0130] In one example, in order to ensure that the liquid working medium adsorbed by the first capillary structure 2 in the second region is replenished to the first region 11 in a timely manner, the third portion of the first capillary structure 2 in the transition region can be relatively wide to reduce the liquid return resistance of the liquid working medium, so that the liquid working medium adsorbed by the first capillary structure 2 in the second region 12 can more easily pass through the transition region and flow back to the first region 11.

[0131] In one example, the liquid working medium adsorbed by the first capillary structure 2 in the first area 11 can be increased to ensure that the liquid working medium in the first area 11 is sufficient. Accordingly, the first inner surface a includes a surface located in the first area 11 and a surface located in the second area 12. For the surface located in the first area 11, the projected area of ​​the first part 21 thereon is greater than the non-projected area, and the non-projected area is greater than or equal to zero.

[0132] Among them, the non-projected area is greater than zero, indicating that the first part 21 does not completely occupy the surface of the first inner surface a in the first region 11, and the non-projected area is equal to zero, indicating that the first part 21 completely occupies the surface of the first inner surface a in the first region 11.

[0133] For example, the first capillary structure 2 is directly located on the first inner surface a. Then, the area of ​​the first inner surface a in the first region 11 covered by the first portion 21 is larger than the area not covered by the first portion 21 .

[0134] In this way, the first part 21 of the first capillary structure 2 in the first region 11 occupies a relatively large area, which can store a large amount of liquid working fluid, thereby ensuring that the liquid working fluid in the first region 11 is always in a relatively full state, thereby avoiding the situation where there is no liquid working fluid available for evaporation in the first region 11, thereby enhancing the heat dissipation effect of the heat spreader.

[0135] In addition, for the surface of the first inner surface a located in the first region 11, the projected area of ​​the first part 21 thereon is larger than the non-projected area, so that the area occupied by the first part 21 in the first region 11 is relatively large, which expands the adsorption area of ​​the first part 21 for adsorbing liquid working fluid in the first region 11, and is also beneficial to increasing the liquid working fluid adsorbed by the first capillary structure 2 in the first region 11.

[0136] In one example, for the surface of the first inner surface a located in the first region 11, the projected area of ​​the first portion 21 thereon is larger than the non-projected area. One implementation method may be to make the width of the first portion 21 located in the first region 11 relatively wide, that is, to widen the width of the first portion 21.

[0137] Another implementation method is to arrange sub-sections around the first section 21. For example, the sub-sections can be arranged on the sides of the first section 21 along the width direction. The first section 21 and the sub-sections can be in contact or close to each other. If they are close to each other, the liquid working medium absorbed by the first section 21 can flow into the sub-sections, allowing the sub-sections to draw liquid working medium from the second section 22 through the first section 21.

[0138] Another implementation manner may be that there are multiple first capillary structures 2 , and the first parts 21 of the multiple first capillary structures 2 are all located in the first region 11 . In this way, the area occupied by the first part 21 in the first region 11 can also be increased.

[0139] In one example, in order to enhance the heat dissipation effect of the heat spreader on the heat source, multiple areas of the heat spreader are usually corresponding to cold sources. Correspondingly, the number of second areas 12 corresponding to the cold sources can be multiple, and the second part 22 of the first capillary structure 2 can be arranged in each second area 12. In this way, the heat absorbed in the first area can be transferred to multiple second areas 12 for heat dissipation through the circulation of the working fluid in the shell.

[0140] For example, as shown in FIG. 2 , there are two second regions 12 , and the two second regions 12 are located on two opposite sides of the first region 11 .

[0141] Of course, the number of the second regions 12 may be greater. For ease of introduction, this embodiment may be illustrated with two second regions 12 .

[0142] In one example, the plurality of second portions 22 may belong to the same capillary structure. For example, as shown in FIG. 3 , the first capillary structure 2 includes a plurality of second portions 22 , wherein the number of the second portions 22 may be equal to the number of the second regions 12 .

[0143] In another example, the multiple second parts 22 may also belong to different capillary structures. For example, referring to Figure 9, the number of first capillary structures 2 is at least two, and the first parts 21 of the at least two first capillary structures 2 are both located in the first area 11, and the second part 22 of each first capillary structure 2 is respectively located in a second area 12.

[0144] For example, as shown in Figure 9, the number of second regions 12 is two, the number of first capillary structures 2 is also two, the first portions 21 of the two first capillary structures 2 are both located in the first region 11, the second portion 22 of one first capillary structure 2 is located in one second region 12, and the second portion 22 of another first capillary structure 2 is located in another second region 12.

[0145] In one example, the first portions 21 of the two oppositely positioned first capillary structures 2 may have an overlapping portion within the first region 11 and in a direction parallel to the first inner surface a.

[0146] For example, the first portions 21 of two opposing first capillary structures 2 have overlapping portions along the width direction of the first portions 21 .

[0147] The first portions 21 of the two opposing first capillary structures 2 have an overlapping portion. This facilitates ensuring that the projected area of ​​the first capillary structures 2 on the first inner surface a within the first region 11 is larger than the unprojected area, thereby increasing the storage capacity of the liquid working medium within the first region 11. Furthermore, this facilitates the arrangement of a larger number of first capillary structures 2 within the limited space within the vapor chamber.

[0148] In one example, the two overlapping first portions 21 may be in contact or close to each other. For example, as shown in FIG9 , the two first portions 21 are close to each other.

[0149] For example, the first portions 21 of at least two first capillary structures 2 are spaced apart in a direction parallel to the first inner surface a.

[0150] In one example, as shown in Figure 9, multiple first parts 21 located in the first area 11 are arranged at intervals and close to each other without contacting each other, which can increase the heat dissipation area in the first area 11. This is because the liquid working medium generally evaporates on the outer surface of the first part 21, and the multiple first parts 21 do not contact each other, which increases the area of ​​the outer surface in the first area 11, thereby increasing the heat dissipation area in the first area 11.

[0151] Similarly, at least one sub-portion may be arranged near the first portion 21 . If adjacent sub-portions do not contact each other and the sub-portions do not contact the first portion 21 , the heat dissipation area in the first region 11 can also be increased.

[0152] In one example, the first capillary structure 2 may be a multi-layer stacked structure, for example, a preformed multi-layer stacked structure.

[0153] The multi-layer stacking structure can increase the number of capillaries in the capillary structure. The more capillaries there are, the greater the adsorption capacity of the capillary structure. Therefore, the first capillary structure 2 adopts a multi-layer stacking structure to increase its adsorption capacity.

[0154] Preforming means that before processing the heat spreader, the multi-layer stacked structure is pre-processed, and then cut into the required shape based on the size of the heat spreader.

[0155] In one example, the multi-layer stacking structure can be achieved through processing methods such as calendering, silk screen printing, 3D printing and electroplating.

[0156] Foam metal is a multi-layer stacked structure, such as copper foam. Accordingly, in one example, the material of the first capillary structure 2 can be foam metal. During production, different pore-forming agents can be selected to achieve different capillary pore diameters at different locations of the first capillary structure 2. For example, when using foam metal to process the first capillary structure 2, a pore-forming agent with a relatively small pore diameter can be selected to process the first portion 21, and a pore-forming agent with a relatively large pore diameter can be selected to process the second portion 22. In this way, the capillary pore diameter of the first portion 21 of the processed first capillary structure 2 is smaller than the capillary pore diameter of the second portion 22.

[0157] Of course, the first capillary structure 2 can also be a multi-layer stacking structure formed by a metal mesh (such as a copper mesh), a multi-layer stacking structure formed by a woven wire bundle of a metal material, a multi-layer stacking structure formed by sintering metal powder (such as copper powder), or a double-layer stacking structure formed by a metal powder slurry (such as a copper powder slurry).

[0158] In one example, a vapor chamber is positioned within an electronic device. The first inner surface a of the housing is located on the outer surface of the housing wall, typically contacting the outer surface of the heat source, while the second inner surface b of the housing is located on the housing wall, typically closer to the outer casing of the electronic device, such as the bottom casing. The first inner surface a and the second inner surface b of the housing 1 are positioned relative to each other. To reduce heat transfer between the vapor chamber and the housing and enhance the user experience, a gap may be provided between the first capillary structure 2 and the second inner surface b of the housing 1, as shown in FIG10 .

[0159] In this way, since the thermal resistance of heat in the gap is relatively large, the heat transfer between the first capillary structure 2 and the shell wall where the second inner surface b is located is relatively weak, and the temperature on the shell wall where the second inner surface b is located is not very high. Therefore, the temperature difference between the shell wall where the second inner surface b is located and the outer shell of the electronic device is relatively small. As a result, the user will basically not feel the heat when in contact with the outer shell of the electronic device, thereby enhancing the user's experience of using the electronic device.

[0160] The above is an introduction to the features of the first capillary structure 2 of the vapor chamber.

[0161] In another example, to enhance the heat dissipation effect of the vapor chamber, the vapor chamber may further include a second capillary structure 3, as shown in Figures 10 and 11. The second capillary structure 3 is located on the first inner surface a, and the projected area of ​​the second capillary structure 3 on the first inner surface a is equal to the area of ​​the first inner surface a. In other words, the second capillary structure 3 completely covers the first inner surface a. In Figure 10, the grid-filled portion is a schematic representation of the second capillary structure 3 being located on the first inner surface a.

[0162] The first capillary structure 2 is located on the surface of the second capillary structure 3 , and the liquid working medium can flow in the first capillary structure 2 and the second capillary structure 3 .

[0163] In one example, as shown in Figure 10, the first capillary structure 2 can be in a strip shape, and the second capillary structure 3 can be in a sheet shape. The area occupied by the second capillary structure 3 is larger than the area occupied by the first capillary structure 2. Therefore, the liquid working fluid adsorbed in the second capillary structure 3 is more than the liquid working fluid adsorbed in the first capillary structure 2. Moreover, the second capillary structure 3 is closer to the heat source. Therefore, the second capillary structure 3 can serve as the main heat dissipation structure of the heat spreader, and the first capillary structure 2 serves as a heat dissipation structure auxiliary to the second capillary structure 3 of the heat spreader.

[0164] It should be noted that in the solution where the heat sink includes the second capillary structure 3, the projected area of ​​the first part 21 on the surface of the first inner surface a located in the first region 11 is larger than the non-projected area, and the non-projected area is not zero.

[0165] This is because, as described above, a non-projected area greater than zero indicates that the first portion 21 does not fully occupy the surface of the second capillary structure 3 in the first region 11, and a non-projected area equal to zero indicates that the first portion 21 fully occupies the surface of the second capillary structure 3 in the first region 11. If the first portion 21 occupied the entire area of ​​the second capillary structure 3 within the first region 11, heat from the heat source would first be transferred to the shell wall where the first inner surface a is located, then to the second capillary structure 3, and then to the first capillary structure 2, and then dissipated outward. This would result in a longer heat dissipation path, and the heat dissipation effect from the heat source would be compromised. Therefore, in the embodiment with the second capillary structure 3, the projected area of ​​the first capillary structure 2 on the surface of the first inner surface a located in the first region 11 is smaller than the surface area of ​​the first inner surface a located in the first region 11. In other words, the first portion 21 does not fully cover the surface of the second capillary structure 3 in the first region 11.

[0166] In an example, the second capillary structure 3 may include different capillary pore diameters. For example, the capillary pore diameter of the second capillary structure 3 in the second region 12 is larger than the capillary pore diameter of the second capillary structure 3 in the first region 11 .

[0167] Because the second capillary structure 3 has a small capillary pore size in the first region 11 and a large capillary pore size in the second region 12 , the capillary force and permeability of the second capillary structure 3 can be balanced, so that the second capillary structure 3 has a larger capillary force in the first region 11 and a larger permeability in the second region 12 .

[0168] In this way, the liquid working medium adsorbed by the second capillary structure 3 in the second region 12 can relatively easily flow back to the first region 11 , and the liquid working medium can relatively easily be adsorbed in the first region 11 .

[0169] In one example, in order to further balance the capillary force and the permeability, the capillary pore diameters of the first capillary structure 2 and the second capillary structure 3 may be different.

[0170] For example, the capillary pore size of the first capillary structure 2 may be larger than the capillary pore size of the second capillary structure 3. As an example, the second capillary structure 3 may be a metal mesh with a large mesh size (such as a copper mesh), and the first capillary structure 2 may be a coarse metal mesh (such as a copper mesh), wherein the larger the mesh size, the smaller the capillary pore size.

[0171] For another example, the capillary pore diameter of the first capillary structure 2 may be smaller than the capillary pore diameter of the second capillary structure 3 .

[0172] In an example, as described above, the first capillary structure 2 may be a multi-layer stacked structure, and the second capillary structure 3 may also be a multi-layer stacked structure, for example, a preformed multi-layer stacked structure.

[0173] The processing method for the layer stacking structure is similar to the above and will not be further illustrated here.

[0174] Similarly, the second capillary structure 3 may be made of foamed metal, such as foamed copper. During fabrication, the second capillary structure 3 may be formed into a second capillary structure 3 having large and small pores using pore-forming agents with different pore sizes, so that the capillary pore size of the portion of the second capillary structure 3 within the second region 12 is larger than the capillary pore size of the portion within the first region 11.

[0175] Of course, the second capillary structure 3 can also be a multi-layer stacking structure formed by a metal mesh (such as a copper mesh), a multi-layer stacking structure formed by a woven wire bundle of a metal material, a multi-layer stacking structure formed by sintering metal powder (such as copper powder), or a double-layer stacking structure formed by a metal powder slurry (such as a copper powder slurry).

[0176] Based on the above, one structure of the vapor chamber may include a first capillary structure, which is located on the first inner surface a of the housing 1. Another structure of the vapor chamber may include a first capillary structure and a second capillary structure, wherein the second capillary structure is in a sheet shape and is laid on the first inner surface a, and the area of ​​the second capillary structure is equal to the area of ​​the first inner surface a, and the first capillary structure is in a strip shape and is located on the surface of the second capillary structure.

[0177] Taking the latter structure of the vapor chamber as an example, when the vapor chamber dissipates heat from a heat source, the liquid working fluid adsorbed by the first and second capillary structures in the first region undergoes a phase change due to heat, evaporating into a gaseous working fluid. The gaseous working fluid then flows to the second region, where it is cooled and condenses into a liquid working fluid. The liquid working fluid is then adsorbed by the first and second capillary structures in the second region and, under the action of capillary forces, flows back into the first and second capillary structures in the first region, awaiting another phase change and evaporation into a gaseous working fluid. This cycle continues to dissipate heat from the heat source.

[0178] In the disclosed embodiment, the second portion of the first capillary structure within the second region includes a main structure and a branch structure, wherein the branch structure includes at least one branch. This allows the liquid working medium within the second region to be adsorbed as much as possible within the first capillary structure, preventing the unabsorbed liquid working medium from freezing at low temperatures. Once ice forms within the vapor chamber at low temperatures, the vapor chamber shell will essentially remain flat, maintaining a flat surface and preventing any interference with the heat source in contact with the vapor chamber.

[0179] For example, the branch structure corresponds to the area where the cold source is located. Then, the branch structure includes at least one branch, which can adsorb the liquid working medium in the area corresponding to the cold source in the first capillary structure as much as possible to prevent the unabsorbed liquid working medium from freezing at low temperatures.

[0180] In addition, since the second part of the first capillary structure in the second region includes a trunk structure and a branch structure, and the branch structure includes at least one branch, the area occupied by the first capillary structure in the second region can be increased, and the adsorption range of the first capillary structure in the second region for adsorbing liquid working fluid can be increased, thereby adsorbing liquid working fluid at more positions or even all positions in the second region, which will further reduce or even eliminate the unadsorbed liquid working fluid in the second region.

[0181] In addition, the first capillary structure absorbs a large amount of liquid working fluid in the second area, so the liquid working fluid can be replenished to the first area in time to avoid the situation where there is no liquid working fluid available for evaporation in the first area, so that the first area always maintains evaporable liquid working fluid, thereby improving the heat dissipation effect of the heat spreader.

[0182] This embodiment also provides a heat spreader, as shown in Figure 12, which also includes a shell 1, a first capillary structure 2 and a working fluid. On this basis, it also includes a third capillary structure 4. The first capillary structure 2, the working fluid and the third capillary structure 4 are all located in the shell 1, and the projected area of ​​the first capillary structure 2 on the first inner surface a of the shell 1 is smaller than the area of ​​the first inner surface a, so that a cavity 10 can be formed in the shell 1. The working fluid in a liquid state is located in the first capillary structure 2 and the third capillary structure 4, and the working fluid in a gaseous state is located in the cavity 10.

[0183] The area within the shell 1 includes a first area 11 and a second area 12, the first area 11 corresponds to the heat source, the second area 12 is different from the first area 11, the first capillary structure 2 includes a first part 21 located in the first area 11 and a second part 22 located in the second area 12, and the third capillary structure 4 is located in the second area 12, and the third capillary structure 4 is used to flow the adsorbed liquid working medium to the first area 11.

[0184] In one example, the structure of the housing 1 can be referred to above and will not be described in detail here. The features of the first capillary structure 2 can be the structural features shown in FIG12 or can have the features of the first capillary structure 2 described above.

[0185] As shown in Figure 12, the second region contains not only the second portion of the first capillary structure but also a third capillary structure. The capillary structure occupies a larger area in the second region, allowing the liquid in the second region to be absorbed by the first capillary structure as much as possible, preventing unabsorbed liquid from freezing at low temperatures. Once ice forms within the vapor chamber at low temperatures, the vapor chamber shell will remain essentially flat, maintaining a flat surface and preventing any interference with the heat source in contact with it.

[0186] In one example, the third capillary structure and the second portion are in contact or close to each other, so that the liquid working medium adsorbed by the third capillary structure can flow back to the first portion in the first region through the second portion.

[0187] In one example, the vapor chamber may further include a second capillary structure 3, the features of which can be found in the description above. As shown in Figure 12 , the second capillary structure 3 is located on the first inner surface a, and the projected area of ​​the second capillary structure 3 on the first inner surface a is equal to the area of ​​the first inner surface a. In other words, the second capillary structure 3 covers the entire first inner surface a. In Figure 12 , the grid-filled portion illustrates the second capillary structure 3 located on the first inner surface a.

[0188] The first capillary structure 2 and the third capillary structure 4 are both located on the surface of the second capillary structure 3 , and the liquid working medium can flow in the first capillary structure 2 , the third capillary structure 4 and the second capillary structure 3 .

[0189] The features of the second capillary structure 3 can be found in the above description and will not be described in detail here.

[0190] This embodiment further provides an electronic device, which may be a mobile phone, a laptop computer, or a tablet computer. The electronic device includes a heat source and the aforementioned vapor chamber, wherein the outer surface of a first shell wall of the vapor chamber contacts the outer surface of the heat source at a position corresponding to the first region, wherein the first shell wall is the shell wall corresponding to the first inner surface a, for example, the first shell wall is the shell wall where the first inner surface is located.

[0191] In one example, thermal interface materials (TIM) may be filled between the first shell wall of the vapor chamber and the heat source to eliminate the contact gap between the vapor chamber and the heat source, enhance heat transfer between the two, and strengthen the heat dissipation effect of the heat source.

[0192] In one example, the electronic device may further include a cooling source, which may be a fan. The second region of the vapor chamber may be adjacent to the fan, and heat released by condensation in the second region may be absorbed by air cooling.

[0193] As described above, the first capillary structure of the electronic device's vapor chamber, within the second region, comprises a main structure and a branch structure, each of which includes at least one branch. This allows the liquid working medium within the second region to be absorbed by the first capillary structure as much as possible, preventing unabsorbed liquid working medium from freezing at low temperatures. If ice forms within the vapor chamber at low temperatures, the vapor chamber's housing will remain substantially free of bulging, maintaining a flat surface and preventing any interference with the heat source in contact with the vapor chamber.

[0194] For example, the branch structure corresponds to the area where the cold source is located. Then, the branch structure includes at least one branch, which can adsorb the liquid working medium in the area corresponding to the cold source in the first capillary structure as much as possible to prevent the unabsorbed liquid working medium from freezing at low temperatures.

[0195] In addition, since the second part of the first capillary structure in the second region includes a trunk structure and a branch structure, and the branch structure includes at least one branch, the area occupied by the first capillary structure in the second region can be increased, and the adsorption range of the first capillary structure in the second region for adsorbing liquid working fluid can be increased, thereby adsorbing liquid working fluid at more positions or even all positions in the second region, which will further reduce or even eliminate the unadsorbed liquid working fluid in the second region.

[0196] In addition, the first capillary structure absorbs a large amount of liquid working fluid in the second area, so the liquid working fluid can be replenished to the first area in time to avoid the situation where there is no liquid working fluid available for evaporation in the first area, so that the first area always maintains evaporable liquid working fluid, thereby improving the heat dissipation effect of the heat spreader.

[0197] The above description is only one embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A heat sink, characterized in that: The heat sink comprises a shell (1), a first capillary structure (2) and a working medium; The first capillary structure (2) and the working medium are both located in the shell (1), and the projection area of ​​the first capillary structure (2) on the first inner surface (a) of the shell (1) is smaller than the area of ​​the first inner surface (a), the shell (1) has a cavity (10), the working medium switches between a gas state and a liquid state, and the working medium in the liquid state is located in the first capillary structure (2), and the working medium in the gas state is located in the cavity (10); The area within the shell (1) comprises a first area (11) and a second area (12), the first area (11) corresponds to an area where a heat source is located, the second area (12) is different from the first area (11), the first capillary structure (2) comprises a first part (21) located in the first area (11) and a second part (22) located in the second area (12), the second part (22) comprises a trunk structure (221) and a branch structure (222), the trunk structure (221) is connected to the first part (21), the branch structure (222) corresponds to an area where a cold source is located, the branch structure (222) comprises at least one branch (223), and each branch (223) is in contact with or close to the trunk structure (221).

2. The vapor chamber according to claim 1, characterized in that: Each of the branches (223) includes at least two sub-branches (224), and each of the sub-branches (224) is connected to the corresponding branch (223).

3. The heat sink according to claim 1 or 2, characterized in that: The capillary pore diameter of the second portion (22) located in the second region (12) is greater than the capillary pore diameter of the first portion (21) located in the first region (11).

4. The vapor chamber according to any one of claims 1 to 3, characterized in that: On the surface of the first inner surface (a) located in the first region (11), the projection area of ​​the first portion (21) is greater than the non-projection area, and the non-projection area is greater than zero.

5. The vapor chamber according to any one of claims 1 to 3, characterized in that: The projection area of ​​the first portion (21) on the surface of the first inner surface (a) located in the first region (11) is equal to the area of ​​the surface of the first portion (21) on the first inner surface (a) located in the first region (11).

6. The vapor chamber according to any one of claims 1 to 5, characterized in that: There are a plurality of second regions (12), and each second region (12) is arranged with the second part (22).

7. The vapor chamber according to claim 6, characterized in that: The heat sink comprises at least two first capillary structures (2); The first parts (21) of the at least two first capillary structures (2) are both located in the first region (11), and the second part (22) of each first capillary structure (2) is respectively located in one of the second regions (12).

8. The vapor chamber according to claim 7, characterized in that: The first parts (21) of the at least two first capillary structures (2) have overlapping parts in a direction parallel to the first inner surface (a).

9. The vapor chamber according to claim 7, characterized in that: The first parts (21) of the at least two first capillary structures (2) are arranged at intervals in a direction parallel to the first inner surface (a).

10. The vapor chamber according to any one of claims 1 to 9, characterized in that: There is a gap between the first capillary structure (2) and the second inner surface (b) of the shell (1), and the second inner surface (b) is an inner surface opposite to the first inner surface (a).

11. The vapor chamber according to any one of claims 1 to 4, or 6 to 10, characterized in that: The heat spreader also includes a second capillary structure (3); The second capillary structure (3) completely covers the first inner surface (a); The first capillary structure (2) is located on the surface of the second capillary structure (3), and the working medium in a liquid state is located in the first capillary structure (2) and the second capillary structure (3).

12. The vapor chamber according to claim 11, characterized in that: The capillary pore diameter of the second capillary structure (3) in the second region (12) is greater than the capillary pore diameter of the second capillary structure (3) in the first region (11).

13. The vapor chamber according to claim 11 or 12, characterized in that: The capillary pore diameter of the first capillary structure (2) is different from the capillary pore diameter of the second capillary structure (3).

14. The vapor chamber according to any one of claims 11 to 13, characterized in that: The material of the second capillary structure (3) is foam metal.

15. The vapor chamber according to any one of claims 1 to 14, characterized in that: The material of the first capillary structure (2) is foam metal.

16. The vapor chamber according to any one of claims 1 to 15, characterized in that: The first capillary structure (2) is a multi-layer stacked structure.

17. The vapor chamber according to any one of claims 11 to 14, characterized in that: The second capillary structure (3) is a multi-layer stacked structure.

18. The vapor chamber according to claim 16 or 17, characterized in that: The multi-layer stack structure is preformed.

19. The vapor chamber according to any one of claims 16 to 18, characterized in that: The multi-layer stacking structure is processed by one of calendering, silk screen printing, 3D printing and electroplating.

20. An electronic device, characterized in that: The electronic device comprises a heat source and a heat spreader as described in any one of claims 1 to 19, wherein a first shell wall of the heat spreader contacts the heat source at a position corresponding to the first region (11), and the first shell wall is a shell wall corresponding to the first inner surface (a).

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