Vapor chamber, vapor chamber manufacturing method, and electronic device

Abstract

Embodiments of the present application provide a vapor chamber, a vapor chamber manufacturing method, and an electronic device. The vapor chamber comprises a first cover plate, a second cover plate, and a support structure. The second cover plate and the first cover plate are connected to surround and define a sealed cavity. The support structure is located in the sealed cavity, and is connected between the first cover plate and the second cover plate. The support structure divides the sealed cavity into at least two channels. At least one channel is a vapor channel, and at least one channel is a capillary channel, the vapor channel being in communication with the capillary channel. The vapor chamber of the present application effectively dissipates heat from a heat source and enables a thin and lightweight design for electronic devices.

Description

Heat spreader, its manufacturing method, and electronic equipment

[0001] This application claims priority to Chinese Patent Application No. 202411219837.5, filed on August 30, 2024, entitled "Heat Spreader Plate, Method of Manufacturing Heat Spreader Plate and Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of terminal technology, and in particular to heat spreaders, methods for manufacturing heat spreaders, and electronic devices. Background Technology

[0003] A vapor chamber (VC) is a heat dissipation device used in electronic devices. The inner wall of a vapor chamber has a capillary structure, which can be filled with a cooling medium. The vapor chamber uses the cooling medium to evenly dissipate heat from heat sources (such as chips and batteries) in the electronic device, and utilizes the capillary force of the capillary structure to return the cooling medium to the heat source area, thus circulating heat dissipation and ensuring that the phone does not overheat, affecting user experience.

[0004] To achieve a thinner and lighter design for electronic devices, the internal structure, such as heat dissipation devices and the mid-frame plate, also needs to be thinned. One side of the mid-frame plate is connected to the display screen, while the other side can be used to support the circuit board and battery. Therefore, in related technologies, using a heat spreader as the mid-frame plate can reduce the thickness of the mid-frame plate, thereby improving the problem of the large thickness of electronic devices.

[0005] As the middle frame plate, the heat exchanger needs to meet good load-bearing requirements. However, if the heat exchanger is to meet good load-bearing requirements, the thickness of the heat exchanger needs to be designed to be large, which can easily lead to a small space for the thermal structure inside the heat exchanger. Due to insufficient effective phase change space, the heat exchanger is limited and it is difficult to achieve efficient heat exchange over a large area. Summary of the Invention

[0006] This application provides a heat spreader, a method for manufacturing the heat spreader, and an electronic device, which can achieve effective heat dissipation from the heat source, enable a thinner and lighter design for the electronic device, improve the reliability of the electronic device, and enhance the user experience.

[0007] Firstly, embodiments of this application provide a heat spreader. The heat spreader includes:

[0008] First cover plate;

[0009] The second cover plate is connected to the first cover plate and forms a sealed cavity;

[0010] A support structure is located in the sealed cavity. The support structure connects the first cover plate and the second cover plate. The support structure divides the sealed cavity into at least two channels, wherein at least one channel is a steam channel and at least one channel is a capillary channel. The steam channel and the capillary channel are connected.

[0011] This application provides a support structure for the first and second cover plates, thereby increasing the strength of the first and second cover plates at the corresponding support structures. In the event of a relative negative pressure environment in the sealed cavity, the support structure can reduce the possibility of the first and second cover plates collapsing into the sealed cavity, thus preventing deformation of the first and second cover plates.

[0012] Because the supporting structure can be used to increase the strength of the first and second cover plates, thereby improving the overall strength of the heat spreader, the structural strength of the heat spreader can meet the requirements for fixing components such as the motherboard and battery. This eliminates the need for a separate middle plate structure for fixing these components in electronic devices. This allows for the reduction of components, enabling the electronic device to be made thinner and lighter, and also reduces the number of parts, lowering raw material costs, assembly costs, and maintenance costs.

[0013] In this embodiment, the heat spreader's overall structural strength can be improved through a supporting structure. The thickness of the first and second cover plates can be reduced to achieve a thinner heat spreader, thereby enabling the electronic device to be made lighter and thinner. Furthermore, due to the increased structural strength of the heat spreader, deformation can be avoided during vacuum degassing. In addition, the supporting structure can form vapor channels and capillary channels to improve heat dissipation efficiency while enhancing overall strength.

[0014] In some embodiments, at least one of the first cover plate and the second cover plate is provided with a support structure. The support structure may be disposed on the first cover plate. The support structure may abut against the surface of the second cover plate facing the first cover plate. Alternatively, the support structure may also be disposed on the second cover plate. The support structure may abut against the surface of the first cover plate facing the second cover plate. The support structure can be used to form multiple support points between the first cover plate and the second cover plate to improve the overall strength of the heat spreader.

[0015] In some embodiments, the support structure includes a first support portion and a second support portion, the first support portion being disposed on a first cover plate and the second support portion being disposed on a second cover plate. There are multiple first support portions, with a first gap formed between adjacent first support portions; there are multiple second support portions, with a second gap formed between adjacent second support portions; the first and second support portions abut against each other, and the first and second gaps are connected to form a steam passage.

[0016] Since the first support portion can enhance the strength of the first cover plate, and the second support portion can enhance the strength of the second cover plate, the first and second cover plates can be designed to be thinner and lighter while still maintaining their strength, which is beneficial for achieving a thinner and lighter design in electronic devices. It is easy to understand that thinning the first and second cover plates can increase the space along the first direction of the steam channel.

[0017] In some embodiments, the end face of the first support portion facing the second support portion is provided with a first groove, and the end face of the second support portion facing the first support portion is provided with a second groove. When the first support portion and the second support portion abut against each other, the first groove and the second groove form a capillary channel.

[0018] By providing a first groove on the first support portion and a second groove on the second support portion, the first and second grooves can communicate with each other and form a capillary channel when the first and second support portions abut against each other along the first direction. The liquid cooling medium can flow within the capillary channel under the action of capillary force.

[0019] The end face of the first support portion facing the second cover plate is recessed to form a first groove. The formation of this first groove can easily reduce the strength of the first support portion. Therefore, by providing the first groove on the end face of the first support portion away from the first cover plate, the impact on the strength of the first cover plate can be minimized when used to form a capillary channel. The capillary channel does not require additional space on the first cover plate. This reduces the possibility of encroaching on the structural space of the first cover plate due to the presence of a capillary channel, which would hinder the design of thinner and lighter electronic devices. Furthermore, it also reduces the possibility of affecting the structural strength of the first cover plate by providing a first groove or capillary channel at other locations on the first cover plate.

[0020] Similarly, the end face of the second support facing the first cover plate is recessed to form a second groove. The formation of the second groove can easily reduce the strength of the second support. Therefore, by providing a second groove on the end face of the second support away from the second cover plate, the impact on the strength of the second cover plate can be minimized when used to form a capillary channel. Furthermore, since the first cover plate has a portion of the capillary channel structure (i.e., the first groove) and the second cover plate has a portion of the capillary channel structure (the second groove), and the capillary channel is not completely formed on either the first or second cover plate, the first and second cover plates can respectively bear the strength reduction caused by the formation of the capillary channel, thereby making the structural strength of the first and second cover plates relatively balanced.

[0021] In some embodiments, along a first direction, the first support portion includes a plurality of first grooves, and the second support portion includes a plurality of second grooves, with each first groove corresponding to one of the second grooves to form a plurality of capillary channels on the support structure. The capillary channels can be used to circulate a liquid cooling medium. By providing multiple capillary channels, the flow burden of the liquid cooling medium can be distributed, increasing the flow rate of the liquid cooling medium. Furthermore, by providing multiple capillary channels, the liquid cooling medium can also flow from different areas away from the heat source towards the heat source, which is beneficial for improving the uniformity of the liquid cooling medium flow.

[0022] In some embodiments, the support structure may have multiple through holes for connecting multiple capillary channels, and these through holes may also be used to connect the capillary channels and the vapor channel. The through holes allow the capillary channels to be interconnected, thereby increasing the circulation rate of the liquid cooling medium and improving heat dissipation efficiency. Furthermore, the through holes can also connect the capillary channels and the vapor channel, so that when vaporization occurs in the high-temperature region of the capillary channel, the vapor cooling medium can enter the vapor channel through the through holes and flow from the vapor channel to the low-temperature region.

[0023] In some embodiments, the heat spreader has a high-temperature region and a low-temperature region, the high-temperature region being opposite to the heat source and the low-temperature region being away from the heat source; wherein, one end of the capillary channel is located in the high-temperature region and one end of the steam channel is located in the low-temperature region.

[0024] When there are multiple capillary channels, one end of each capillary channel is located in the high-temperature region. The liquid cooling medium formed by liquefaction in the low-temperature region can be introduced into the high-temperature region, allowing the cooling medium to concentrate in the high-temperature area and improving the heat dissipation efficiency of the heat source. When there are multiple steam channels, one end of each steam channel is located in the low-temperature region. This allows the gaseous cooling medium produced by vaporization to undergo a complete liquefaction reaction in the low-temperature region, forming a liquid cooling medium, thereby improving the recycling rate of the cooling medium.

[0025] In some embodiments, the support structure includes a peripheral channel surrounding the capillary channel and the steam channel, and the peripheral channel is connected to the capillary channel and the steam channel.

[0026] Since the first support and the second support abut against each other along the first direction to form a steam channel and a capillary channel, the steam channel and the capillary channel can be arranged side by side on the end faces of the first support and the second support that abut against each other. Therefore, an outer peripheral channel can be provided on the outer edge of this end face of the heat spreader. The steam channel and the capillary channel in the heat spreader are both connected to the outer peripheral channel. Therefore, by degassing the outer peripheral channel, both the steam channel and the capillary channel can be vacuumed, thereby degassing the entire sealed cavity.

[0027] In some embodiments, the peripheral channel is a steam channel. Since the steam channel has a larger internal space than the capillary channel, degassing the sealed cavity through the steam channel can effectively improve degassing efficiency. It should be noted that the peripheral channel and all steam channels can be interconnected to degas the entire sealed cavity.

[0028] Alternatively, the peripheral channel may include a steam channel and a capillary channel. The end of the capillary channel away from the heat source may be located in the peripheral channel, so that the ends of multiple capillary channels away from the heat source are connected at the peripheral channel.

[0029] In some embodiments, the width of the steam channel is greater than or equal to 0.5 mm and less than or equal to 2.5 mm. When the wall thickness of the first cover plate remains constant, a width of 0.5 mm or more for the steam channel allows for an increase in the space of the steam channel. Since increasing the space of the steam channel reduces the flow resistance of the gaseous cooling medium, the internal space of the steam channel can be increased to improve the flowability of the gaseous cooling medium, thereby improving heat dissipation efficiency.

[0030] However, when the steam channel is wide, the cavity formed inside the heat spreader is also large, which can easily affect the strength of the heat spreader. For example, when the heat spreader is degassed, the inside of the heat spreader is in a negative pressure environment. Therefore, if the strength of the heat spreader is insufficient, it is easy to deform during the degasing process. Furthermore, if the strength of the heat spreader is insufficient, it is difficult for the heat spreader to meet the strength requirements for fixing components such as batteries and circuit boards.

[0031] Therefore, by setting the width of the steam channel to be greater than or equal to 0.5 mm and less than or equal to 2.5 mm, a larger space can be provided in the steam channel while satisfying the structural strength of the heat spreader, so as to reduce the flow resistance of the gas phase cooling medium and thus meet the heat dissipation requirements of the heat source.

[0032] In some embodiments, the first cover plate has a first wall thickness along a first direction at a first interval, the first wall thickness being greater than or equal to 0.03 mm and less than or equal to 0.05 mm; and / or, the second cover plate has a second wall thickness along the first direction at the steam passage, the second wall thickness being greater than or equal to 0.03 mm and less than or equal to 0.05 mm.

[0033] The thickness of the first wall layer can affect the structural strength of the first cover plate. If the thickness is too small, the first cover plate will be weak, making it prone to deformation when the heat spreader is degassed or used to fix circuit boards, batteries, or other structures. Therefore, setting the thickness of the first wall layer to be greater than or equal to 0.03 mm can effectively solve the above-mentioned technical problems.

[0034] Furthermore, the initial wall thickness also affects the space of the steam channel. When the thickness of the heat spreader remains constant, if the initial wall thickness is set too large, it will occupy space along the first direction of the steam channel, resulting in a reduction in the internal space of the steam channel. Since a smaller steam channel space can easily lead to increased flow resistance of the gaseous cooling medium, thus affecting the heat dissipation effect, setting the initial wall thickness to be less than or equal to 0.05 mm can effectively solve the above-mentioned technical problems.

[0035] Therefore, by setting the first wall thickness to be greater than or equal to 0.03 mm and less than or equal to 0.05 mm, the steam channel can have a larger space while satisfying the structural strength of the heat spreader, so as to reduce the flow resistance of the gas phase cooling medium and thus meet the heat dissipation requirements of the heat source.

[0036] In some embodiments, the width of the capillary channel is greater than or equal to 0.05 mm and less than or equal to 0.12 mm, the width of the first support portion along the first direction is greater than or equal to 0.35 mm and less than or equal to 2.04 mm, and the width of the second support portion along the first direction is greater than or equal to 0.35 mm and less than or equal to 2.04 mm.

[0037] When the width of the capillary channel is too small, for example, less than 0.05 mm, it easily affects the flow rate of the liquid cooling medium, thus impacting the heat dissipation efficiency of the heat source. When the width of the capillary channel is too large, for example, greater than 0.12 mm, it easily leads to an increase in the meniscus radius of the cooling medium within the capillary channel. The meniscus refers to the interface shape of the cooling medium within the capillary channel. An increased meniscus radius reduces capillary force, thus slowing the circulation speed of the liquid cooling medium within the heat spreader, resulting in reduced heat transfer efficiency. Consequently, the heat spreader cannot quickly transfer heat from the heat source to the low-temperature region, leading to overheating of electronic equipment and affecting its normal operation. Therefore, setting the width of the capillary channel to be greater than or equal to 0.05 mm and less than or equal to 0.12 mm effectively solves the above technical problems.

[0038] In some embodiments, in the first cover plate, the depth of the first groove is L1, the width of the first groove is B1, and the depth-to-width ratio of the first groove, L1 / B1, is greater than or equal to 0.5 mm and less than or equal to 0.8 mm.

[0039] The aspect ratio of the first groove can affect capillary force and the flow performance of the cooling medium. When the aspect ratio of the first groove is small, the capacity of the first groove to hold the cooling medium is small, which can easily affect the heat dissipation efficiency of the heat source. When the aspect ratio of the first groove is large, since the deeper channels can provide a larger surface area to generate capillary action, a larger aspect ratio of the first groove can increase the capillary force of the capillary channels.

[0040] However, when the aspect ratio of the first groove is too large, it increases the flow resistance of the liquid cooling medium within the capillary channel. This effect is particularly pronounced when the cooling medium has a high viscosity or when the capillary channel has a long flow path. Therefore, when the aspect ratio of the first groove is within the range of 0.5 mm to 0.8 mm, the heat dissipation efficiency of the heat source can be satisfied while meeting the flow performance requirements of the cooling medium.

[0041] In some embodiments, in the second cover plate, the depth of the second groove is L2, the width of the first groove is B2, and the depth-to-width ratio of the second groove, L1 / B1, is greater than or equal to 0.5 mm and less than or equal to 0.8 mm. The depth-to-width ratio of the second groove can also affect capillary force and the flow performance of the cooling medium. The range of values ​​for the depth-to-width ratio of the second groove can be the same as the range of values ​​for the depth-to-width ratio of the first groove.

[0042] In some embodiments, the first cover plate is provided with a first passivation film, the thickness of which is between 5 nm and 100 nm. The second cover plate is provided with a second passivation film, the thickness of which is between 5 nm and 100 nm.

[0043] Because the capillary channels formed by the first and second cover plates can accommodate liquid-phase cooling media, and the vapor channels formed by the first and second cover plates can accommodate gas-phase cooling media, the first and second cover plates are susceptible to oxidation and corrosion. A first passivation film can form a stable protective layer on the surface of the first cover plate to reduce the likelihood of corrosion by the cooling media. Similarly, a second passivation film can form a stable protective layer on the surface of the second cover plate to reduce the likelihood of corrosion by the cooling media, thereby improving the performance and service life of the heat spreader.

[0044] In some embodiments, the capillary channel has microstructures protruding or recessed into its inner wall. These microstructures promote uniform distribution of the cooling medium throughout the capillary channel, preventing localized drying or over-wetting of the inner wall and enhancing hydrophilicity. This improves the adsorption capacity between the cooling medium and the capillary channel, allowing the cooling medium to remain within the channel and increasing water retention. Furthermore, the microstructures increase the surface area within the capillary channel, thereby enhancing capillary forces and facilitating more efficient flow of the cooling medium. The microstructures also increase the contact area between the liquid and the channel wall, thus improving heat transfer efficiency.

[0045] Secondly, embodiments of this application provide a method for manufacturing a heat spreader, used to prepare a heat spreader as described in any of the above claims, the method comprising:

[0046] A first gap and a first groove are formed on a first cover plate, and a second gap and a second groove are formed on a second cover plate;

[0047] The first cover plate and the second cover plate are chemically passivated to form a first passivation film on the first cover plate and a second passivation film on the second cover plate.

[0048] The first cover plate and the second cover plate are roughened to form microstructures on the inner walls of the first cover plate and the second cover plate opposite to each other;

[0049] The first cover plate and the second cover plate are sealed together so that the first gap and the second gap form a steam channel, and the first groove and the second groove form a capillary channel.

[0050] The manufacturing method of this application includes passivation and roughening treatments. Passivation treatment can be used to form a first passivation film and a second passivation film on the first and second cover plates, respectively, to reduce the possibility of corrosion of the first and second cover plates by the cooling medium, thereby improving the working performance and service life of the heat spreader. Roughening treatment refers to roughening the inner walls of the first and second cover plates to form microstructures within the first and second grooves. This allows microstructures to form on the inner walls of the capillary channels formed by the first and second grooves when the first and second cover plates are sealed together.

[0051] In some embodiments, the first cover plate and the second cover plate are chemically passivated to form a first passivation film on the first cover plate and a second passivation film on the second cover plate. This includes: passivating the first cover plate and the second cover plate with a passivation solution, wherein the passivation solution is a hydrogen peroxide aqueous solution, the mass fraction of the passivation solution is between 0.5% and 3%, the passivation treatment time is 10 min to 2 h, and the passivation treatment temperature is 20°C to 60°C.

[0052] In some embodiments, the first cover plate and the second cover plate are roughened to form microstructures on the inner walls of the opposite sides of the first cover plate and the second cover plate, including: roughening the first cover plate and the second cover plate with a roughening solution, wherein the roughening solution is an aqueous solution containing FeCl3, H2SO4 and H2O2; wherein the concentration of FeCl3 is 10-60 g / L, the concentration of H2SO4 is 30-50 g / L, the concentration of H2O2 is 100-150 ml / L, the roughening treatment time is 20 min-60 min, and the roughening treatment temperature is 40-65℃.

[0053] In some embodiments, after roughening the first cover plate and the second cover plate to form microstructures on the inner walls of the first cover plate and the second cover plate opposite to each other, the method further includes: baking activation of the first cover plate and the second cover plate; the baking activation temperature is 150℃-400℃, the baking activation time is 10min-2h, and the atmosphere is nitrogen.

[0054] Thirdly, embodiments of this application provide an electronic device, including a heat source, a heat spreader as described above, and a middle frame. The heat source is disposed on the heat spreader. The heat spreader is sealed to the middle frame.

[0055] By employing the aforementioned heat spreader, the overall structural strength can be improved through the supporting structure. The thickness of the first and second cover plates can be reduced to achieve a thinner heat spreader, thereby enabling the thinner and lighter design of electronic devices. Furthermore, due to the increased structural strength of the heat spreader, deformation can be prevented during vacuum degassing. In addition, the supporting structure can form vapor channels and capillary channels to improve heat dissipation efficiency from the heat source while enhancing overall strength. Attached Figure Description

[0056] Figure 1 is a schematic diagram of the overall structure of an electronic device provided in an embodiment of this application;

[0057] Figure 2 is an exploded structural diagram of an electronic device provided in an embodiment of this application;

[0058] Figure 3 is an exploded structural diagram of a heat spreader and a middle frame provided in an embodiment of this application;

[0059] Figure 4 is a cross-sectional view of a heat spreader provided in an embodiment of this application;

[0060] Figure 5 is a partial cross-sectional view of another heat spreader provided in an embodiment of this application;

[0061] Figure 6 is a top view of a first cover plate provided in an embodiment of this application;

[0062] Figure 7 is a magnified view of part A in Figure 6;

[0063] Figure 8 is an exploded structural diagram of a heat spreader provided in an embodiment of this application;

[0064] Figure 9 is an exploded structural diagram of another heat spreader provided in an embodiment of this application.

[0065] Reference numerals: 100-Electronic device; 1-Middle frame; 2-Display screen; 3-Heat spreader; 31-First cover plate; 32-Second cover plate; 33-Support structure; 331-First support part; 332-Second support part; 34-Steam channel; 341-First interval; 342-Second interval; 35-Capillary channel; 351-First groove; 352-Second groove; 36-First partition; 36a-Through hole; 37-Outer channel; 38-Mounting part; 4-Graphite heat sink; 5-Heat source; 6-Rear cover; X-First direction. Detailed Implementation

[0066] To facilitate a clear description of the technical solutions in the embodiments of this application, some terms and technologies involved in the embodiments of this application will be briefly introduced below:

[0067] A phase transition refers to the process by which a substance changes from one phase (such as solid, liquid, or gas) to another under certain conditions. Phase transitions are usually accompanied by the absorption or release of energy. For example, the process by which a substance changes from a liquid phase to a gaseous phase can be called vaporization. A liquid substance absorbs heat and can transform into a gaseous substance. Conversely, the process by which a substance changes from a gaseous phase to a liquid phase can be called liquefaction. A gaseous substance releases heat and can transform into a liquid substance.

[0068] A vapor chamber, also known as a heat exchanger, superconducting heat exchanger, heat-conducting plate, or vapor chamber (VC), works similarly to a heat pipe. It utilizes the boiling phase transition of the working fluid (cooling medium) within a sealed cavity—from liquid to gas (absorbing heat) and from gas to liquid (releasing heat). Capillary action and gravity act as the transport forces for the liquid working fluid, completing the phase change cycle between the gas and liquid phases in the high-temperature and low-temperature regions of the vapor chamber. This allows for efficient heat exchange through latent heat of phase change, heat conduction, and convection. The high-temperature region refers to the area on the vapor chamber where the heat source is located, while the low-temperature region refers to the area on the vapor chamber furthest from the heat source.

[0069] In the embodiments of this application, terms such as "first" and "second" are used to distinguish identical or similar items with substantially the same function and purpose. For example, "first chip" and "second chip" are used only to distinguish different chips and do not limit their order of execution. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or execution order, and that "first" and "second" do not necessarily imply that they are different.

[0070] It should be noted that, in the embodiments of this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0071] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, a--c, bc, or abc, where a, b, and c can be single or multiple.

[0072] This application provides an electronic device. The electronic device can be referred to as user equipment (UE) or a terminal. For example, the electronic device can be a portable Android device (PAD), a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device, an in-vehicle device, a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical care, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. This application does not specifically limit the form of the electronic device.

[0073] Driven by the demand for thinner and lighter electronic devices, structures such as heat dissipation devices and mid-frame panels used in these devices also need to be thinner. The mid-frame panel is located between the display screen and the battery. One side of the mid-frame panel is connected to the display screen, while the other side can be used to fix other structures, such as circuit boards or batteries. Using a heat spreader as the mid-frame panel can save the space originally occupied by the traditional mid-frame panel, thus enabling a thinner design for electronic devices.

[0074] Because the sealed cavity of a vapor chamber requires vacuum degassing, and the vapor chamber can be used to fix circuit boards and batteries, it needs to have good strength to meet load-bearing requirements and prevent deformation. In related technologies, the vapor chamber is typically designed to be quite thick to meet these strength requirements. However, increasing the thickness of the vapor chamber can lead to a smaller thermal structure space within it. Limited effective phase change space makes it difficult to achieve efficient heat exchange over a large area, which can affect the heat dissipation efficiency of the heat source and the normal operation of electronic devices. Especially when the display screen of an electronic device is large, the corresponding battery size is also large, making it even more difficult to balance the strength and heat dissipation requirements of the vapor chamber.

[0075] Therefore, in order to solve the above-mentioned technical problems, this application provides a heat spreader, a method for manufacturing a heat spreader, and an electronic device, which can realize the effective heat dissipation of the heat source by the heat spreader, improve the reliability of the electronic device, and realize the thin and light design of the electronic device, thereby enhancing the user experience.

[0076] Figure 1 schematically shows an overall view of an electronic device 100. Referring to Figure 1, the electronic device 100 is a handheld device with wireless communication capabilities. For example, a handheld device with wireless communication capabilities could be a mobile phone.

[0077] When the handheld device with wireless communication capabilities is a mobile phone, the mobile phone can be a foldable phone as shown in Figure 1, or it can be a non-foldable phone. Compared to non-foldable phones, foldable phones can change the configuration of electronic device 100, making electronic device 100 foldable. While meeting the user's need for electronic device 100 to have a large display screen 2, it can also make it easy for the user to carry.

[0078] The structure of the electronic device 100 of this application will be further described below using the foldable mobile phone shown in Figure 1 as an example.

[0079] Figure 2 schematically shows an exploded view of the electronic device 100 in Figure 1. Only a portion of the electronic device 100 is shown in Figure 2.

[0080] The structure of the electronic device 100 is described in detail below with reference to Figures 1 and 2.

[0081] Referring to Figures 1 and 2, the electronic device 100 includes a housing and a display screen 2. The housing is the main supporting structure 33 of the electronic device 100. The display screen 2 is mounted on the housing. The display screen 2 provides a display interface and a user interface for the electronic device 100. The display screen 2 may be, but is not limited to, an organic light-emitting diode (OLED) display screen 2. For example, in some embodiments, the display screen 2 may also be a micro organic light-emitting diode (micro OLED) display screen 2, etc. This application does not impose limitations on the embodiments described.

[0082] Referring to Figure 2, the housing can be the mid-frame 1 of an electronic device 100 (e.g., a mobile phone). The electronic device 100 may also include a heat spreader 3. The heat spreader 3 can be used to support structures such as circuit boards, batteries, and camera modules, and can also be used for circulating heat dissipation of the heat source 5 (heat-generating components) in the above structures. The heat source 5 is disposed on one side surface of the heat spreader 3, and the heat spreader 3 can be fixedly connected to the mid-frame 1. Therefore, the electronic device 100 does not need to have an additional mid-plate for fixing the above structures, which is beneficial for achieving a thinner and lighter design of the electronic device 100.

[0083] Referring again to Figure 2, the electronic device 100 may also include a graphite heat sink 4. The graphite heat sink 4 is located between the display screen 2 and the heat spreader 3. The graphite heat sink 4 can utilize the thermal conductivity of graphite material to evenly distribute the heat inside the electronic device 100 and dissipate heat through airflow.

[0084] The heat source 5 is disposed on one side surface of the heat spreader 3. Referring to Figure 2, in this embodiment, the heat source 5 can be a battery, and the heat source 5 can be located on the side of the heat spreader 3 facing away from the display screen 2. The heat source 5 can be fixed to the heat spreader 3 by means of, but is not limited to, adhesive bonding, screw fastening, etc.

[0085] Figure 3 shows an exploded structural view of a heat spreader 3 and a middle frame 1 provided in an embodiment of this application. Figure 4 shows a cross-sectional structural schematic diagram of a heat spreader 3 provided in an embodiment of this application.

[0086] Referring to Figures 3 and 4, the heat spreader 3 and the middle frame 1 can be fixed to the middle frame 1 by means of adhesive bonding, screw fastening, or other methods. For example, the mounting portion 38 of the heat spreader 3 can overlap the middle frame 1. Adhesive can be applied to the overlapping surfaces of the mounting portion 38 and the middle frame 1 for sealing. The mounting portion 38 of the heat spreader 3 can be locked to the middle frame 1 by screws. Then, adhesive can also be applied between the heat spreader 3 and the middle frame 1 along the outer edge of the heat spreader 3. E in Figure 3 indicates the adhesive structure formed between the heat spreader 3 and the middle frame 1. The sealing treatment between the heat spreader 3 and the middle frame 1 can be used to prevent external moisture from entering the electronic device 100.

[0087] The surface of the heat spreader 3 is typically coated with insulating materials such as insulating varnish, ink, or electrophoresis. Therefore, as shown in Figure 4, when the heat spreader 3 is electrically connected to the middle frame 1, the insulating material in the area where the mounting portion 38 of the heat spreader 3 contacts the middle frame 1 can be removed to allow electrical connection between the conductive material of the heat spreader 3 and the middle frame 1. This can be achieved by laser engraving.

[0088] Referring again to Figures 2 and 4, the electronic device 100 may further include a rear cover 6. The rear cover 6 is disposed on the side of the housing away from the display screen 2 and is connected to the housing to secure the rear cover 6 to the housing. The rear cover 6 and the housing may form another cavity within the electronic device 100 to accommodate structures such as circuit boards and batteries, thereby further enabling the assembly of the circuit boards, batteries, and other structures within the cavity formed by the rear cover 6 and the housing.

[0089] Circuit boards (not shown) typically house a large number of electronic components. These components may include processor modules, system-on-chips (SoCs), memory modules, communication modules, radio frequency modules, charging management modules, and power management ICs (PMICs).

[0090] Referring again to Figure 4, the heat spreader 3 may include a first cover plate 31, a second cover plate 32, and a support structure 33. The first cover plate 31 and the second cover plate 32 are connected to form a sealed cavity. The support structure 33 is located within the sealed cavity. The support structure 33 can divide the sealed cavity into at least two channels, wherein at least one channel is a steam channel 34 and at least one channel is a capillary channel 35. The steam channel 34 and the capillary channel 35 are connected.

[0091] Capillary channel 35 and vapor channel 34 are important structures in the heat spreader 3. Capillary channel 35 is a key structure in the heat spreader 3 used to transfer the liquefied cooling medium back to the corresponding area of ​​the heat source 5. Capillary channel 35 can be used to fill the cooling medium. Vapor channel 34 is a key component used to transfer the gas formed after the cooling medium vaporizes and evaporates in the corresponding area of ​​the heat source 5 to the low-temperature area. Therefore, capillary channel 35 and vapor channel 34 can be used to circulate and dissipate heat from the heat source 5 in the electronic device 100.

[0092] The capillary channel 35 can provide capillary force for the cooling medium to flow towards the heat source 5. Since the temperature and pressure of the area corresponding to the heat source 5 in the sealed cavity of the heat spreader 3 are higher, and the temperature and pressure of the area away from the heat source 5 are lower, the cooling medium can flow in the capillary channel 35 under the action of pressure difference and capillary force. Furthermore, the gas formed after the cooling medium vaporizes and evaporates can flow along the vapor channel 34.

[0093] The cooling medium can be, but is not limited to, water, deionized water, methanol, acetone, etc. This application describes an example where the cooling medium is water.

[0094] Under normal conditions, the boiling point of the cooling medium is 100°C. Therefore, the cooling medium in the heat spreader 3 will only boil and absorb heat from the heat source 5 when the heat source 5 reaches 100°C. However, when the heat source 5 reaches 100°C, the electronic device 100 will not function properly. Therefore, the sealed cavity of the heat spreader 3 can be set to a vacuum environment. It is understood that the boiling point of the cooling medium will decrease in a vacuum environment. Therefore, by lowering the boiling point of the cooling medium through a vacuum environment, it can evaporate and boil when the temperature of the heat source 5 is below 100°C (e.g., 40°C, 30°C), thus dissipating heat from the heat source 5. Therefore, the air pressure inside the sealed cavity is lower than the external air pressure, and the sealed cavity can be in a relatively negative pressure vacuum environment.

[0095] Referring again to Figure 4, the support structure 33 is located within the sealed cavity and connects the first cover plate 31 and the second cover plate 32. Therefore, the support structure 33 can provide support for the first cover plate 31 and the second cover plate 32 to improve the strength of the first cover plate 31 and the second cover plate 32 at the corresponding points of the support structure 33. Thus, under a relatively negative pressure environment in the sealed cavity, the support structure 33 can reduce the possibility of the first cover plate 31 and the second cover plate 32 concave towards the sealed cavity, causing deformation of the first cover plate 31 and the second cover plate 32.

[0096] Since the support structure 33 can be used to improve the strength of the first cover plate 31 and the second cover plate 32, thereby improving the overall strength of the heat spreader 3, the structural strength of the heat spreader 3 can meet the requirements for fixing components such as the motherboard and battery. Therefore, the electronic device 100 no longer needs a separate middle plate structure for fixing components such as the motherboard and battery. This allows for a reduction in the number of components, resulting in a thinner and lighter electronic device 100, and also reduces the number of parts, lowering raw material costs, assembly costs, and maintenance costs.

[0097] Referring again to Figure 4, the number of support structures 33 may be, but is not limited to, one, to form multiple steam channels 34 and multiple capillary channels 35. The number of support structures 33 is not specifically limited in this embodiment.

[0098] It should be noted that the specific location of the support structure 33 on the first cover plate 31 or the second cover plate 32 is not particularly limited in this embodiment. The support structure 33 may be provided on at least one of the first cover plate 31 and the second cover plate 32. For example, the support structure 33 may be provided on the first cover plate 31. The support structure 33 may abut against the surface of the second cover plate 32 facing the first cover plate 31. Alternatively, the support structure 33 may also be provided on the second cover plate 32. The support structure 33 may abut against the surface of the first cover plate 31 facing the second cover plate 32.

[0099] Furthermore, both the first cover plate 31 and the second cover plate 32 may be provided with a support structure 33. The support structure 33 on the first cover plate 31 may abut against the second cover plate 32, and the support structure 33 on the second cover plate 32 may abut against the first cover plate 31, or the support structure 33 on the first cover plate 31 and the support structure 33 on the second cover plate 32 may abut against each other.

[0100] Referring again to Figure 4, the support structure 33 of this application may include a first support portion 331 and a second support portion 332. The first support portion 331 may be disposed on the first cover plate 31. The second support portion 332 may be disposed on the second cover plate 32. There may be multiple first support portions 331. A first gap 341 may be formed between two adjacent first support portions 331. There may be multiple second support portions 332. A second gap 342 may be formed between two adjacent second support portions 332. The first support portions 331 and the second support portions 332 may abut against each other, so that the first gap 341 and the second gap 342 are connected and form a steam passage 34.

[0101] The first cover plate 31 and the second cover plate 32 can be arranged opposite each other along a first direction (e.g., the X direction in Figure 4). The first interval 341 and the second interval 342 corresponding along the first direction X can be interconnected to form a steam channel 34. The vaporized cooling medium can flow through the steam channel 34 in a direction away from the heat source 5 and condense and liquefy in the region away from the heat source 5.

[0102] In this embodiment, since the first support portion 331 can enhance the strength of the first cover plate 31 and the second support portion 332 can enhance the strength of the second cover plate 32, the first cover plate 31 and the second cover plate 32 can be designed to be thinner and lighter while still maintaining their strength, which is beneficial for achieving a thinner and lighter design of the electronic device 100. It is easy to understand that by making the first cover plate 31 and the second cover plate 32 thinner and lighter, the space of the steam channel 34 along the first direction X can be increased.

[0103] It should be noted that by increasing the space of the steam channel 34, on the one hand, the flow resistance of the gas phase cooling medium can be increased, and on the other hand, a phase change space can be provided for the cooling medium, which is beneficial to improving the heat dissipation effect of the heat source 5.

[0104] Specifically, the first support portion 331 can protrude from the wall surface of the first cover plate 31 facing the second cover plate 32. A first gap 341 can be formed between the wall surface of the first cover plate 31 facing the sealing cavity and the first support portion 331. Since the first support portion 331 can be used to improve the strength of the first cover plate 31, and there can be multiple first support portions 331, a smaller wall thickness of the first cover plate 31 along the first direction X can still meet the strength requirements of the first cover plate 31. By reducing the thickness of the first cover plate 31, more space can be reserved for the first gap 341 along the first direction X, which helps to provide sufficient space for the steam passage 34.

[0105] Similarly, the second support portion 332 can protrude from the wall surface of the second cover plate 32 facing the first cover plate 31. A second gap 342 can be formed between the wall surface of the second cover plate 32 facing the sealing cavity and the second support portion 332. Since the second support portion 332 can be used to improve the strength of the second cover plate 32, and there can be multiple second support portions 332, a smaller wall thickness of the second cover plate 32 along the first direction X can still meet the strength requirements of the second cover plate 32. By reducing the thickness of the second cover plate 32, more space can be reserved for the second gap 342 along the first direction X, which helps to provide sufficient space for the steam passage 34.

[0106] Therefore, the heat spreader 3 provided in this embodiment can improve the structural strength of the first cover plate 31 and the second cover plate 32 while satisfying the phase change space of the cooling medium, thereby improving the overall structural strength of the heat spreader 3. For example, when the thickness of the heat spreader 3 is 0.25mm, it can meet both the strength requirements and the heat dissipation requirements of the heat source 5.

[0107] In some embodiments, the first cover plate 31 and the first support portion 331 may be an integral structure. The second cover plate 32 and the second support portion 332 may be an integral structure. The materials of the first cover plate 31 and the second cover plate 32 may be, but are not limited to, stainless steel, titanium, titanium alloy, etc., and are not particularly limited in the embodiments of this application.

[0108] Table 1 shows the heat dissipation thickness and heat dissipation capacity of the heat dissipation plate 3 in the two related technologies and embodiments of this application.

[0109] As shown in Table 1, in related technology one, the heat dissipation structure consists of a 0.11mm graphite heat sink 4 and a 0.35mm aluminum alloy frame 1, with an overall heat dissipation thickness of 0.46mm. Experimental measurements show that its overall heat dissipation capacity for the electronic device 100 is 49.5mA / ℃. The highest temperature on the electronic device 100 is 39.35℃.

[0110] Referring again to Table 1, in related technology two, the heat dissipation structure consists of a 0.35mm heat spreader 3 and a 0.034mm graphite heat sink 4, with an overall heat dissipation thickness of 0.384mm. Experimental measurements show that its overall heat dissipation capacity for the electronic device 100 is 55.2mA / ℃. The highest temperature on the electronic device 100 is 39.0896℃.

[0111] Referring again to Table 1, in this embodiment, the heat dissipation structure consists of a 0.25mm heat spreader 3 and a 0.034mm graphite heat sink 4, with an overall heat dissipation thickness of 0.284mm. Experimental measurements show that its overall heat dissipation capacity for the electronic device 100 is 55.7mA / ℃. The highest temperature on the electronic device 100 is 38.5448℃. Therefore, the thickness of the heat spreader 3 in this embodiment can be 0.25mm, which is beneficial for the overall thinness and lightness of the electronic device 100. Furthermore, it can effectively reduce the local maximum temperature of the electronic device 100 and improve the overall heat dissipation capacity of the electronic device 100.

[0112] The stiffness of the heat spreader 3 can be verified using a three-bar bending structure test. Specifically, the heat spreader 3 is fixedly supported at both ends, meaning that both ends of the heat spreader 3 can be subjected to an upward supporting force. Then, pressure is applied downwards from above the heat spreader 3. The reaction force of the heat spreader 3 in the pressed area is tested by pressing down a certain distance, and the stiffness of the heat spreader 3 is calculated using this reaction force.

[0113] Table 2 shows the stiffness parameters obtained by performing a three-bar bending structure test on the heat spreader 3 of the present application embodiment and the heat spreader 3 of related technologies.

[0114] As shown in Table 2, in related technologies, the sealing cavity of the heat spreader 3 is a hollow structure, and there is no supporting structure 33 inside the sealing cavity. In this embodiment, the stiffness of the heat spreader 3 can be tested when the first cover plate 31 and the second cover plate 32 are facing upwards. "First cover plate 31 facing upwards" means that when the first cover plate 31 of the heat spreader 3 is facing upwards, the first cover plate 31 is pressed downwards a certain distance. "Second cover plate 32 facing upwards" means that when the second cover plate 32 of the heat spreader 3 is facing upwards, the second cover plate 32 is pressed downwards a certain distance. The downward pressing distances are 0.5 mm and 1.5 mm, respectively.

[0115] Referring to Table 2, in related technologies, the average stiffness of the heat spreader 3 was obtained as 0.34, 0.32, and 0.28 through multiple tests. In this embodiment, when the first cover plate 31 is facing upwards, pressing down on the first cover plate 31 can result in an average stiffness of 0.85 or 0.88 for the heat spreader 3. When the second cover plate 32 is facing upwards, pressing down on the second cover plate 32 can result in an average stiffness of 0.85 or 0.86 for the heat spreader 3. Therefore, it can be seen that the stiffness of the heat spreader 3 in this embodiment is much higher than that of the heat spreader 3 in related technologies.

[0116] In summary, the heat spreader 3 in this embodiment can improve its overall structural strength through the support structure 33. The thickness of the first cover plate 31 and the second cover plate 32 can be reduced to achieve a thinner heat spreader 3, thereby enabling the electronic device 100 to be made lighter and thinner. Furthermore, due to the improved structural strength of the heat spreader 3, deformation of the heat spreader 3 can be avoided during vacuum degassing. In addition, the support structure 33 can form a vapor channel 34 and a capillary channel 35 to improve the heat dissipation efficiency of the heat source 5 while enhancing the overall strength.

[0117] Figure 5 shows a partial cross-sectional view of another heat spreader 3 provided in an embodiment of this application.

[0118] Referring again to Figures 4 and 5, the end face of the first support portion 331 facing the second support portion 332 may be provided with a first groove 351. The end face of the second support portion 332 facing the first support portion 331 may be provided with a second groove 352. When the first support portion 331 and the second support portion 332 abut against each other, the first groove 351 and the second groove 352 form a capillary channel 35.

[0119] By providing a first groove 351 on the first support portion 331 and a second groove 352 on the second support portion 332, the first groove 351 and the second groove 352 can communicate with each other and form a capillary channel 35 when the first support portion 331 and the second support portion 332 abut against each other along the first direction X. The liquid cooling medium can flow in the capillary channel 35 under the action of capillary force.

[0120] Specifically, the end face of the first support portion 331 facing the second cover plate 32 is recessed to form a first groove 351. The formation of the first groove 351 can easily reduce the strength of the first support portion 331. Therefore, by providing the first groove 351 on the end face of the first support portion 331 away from the first cover plate 31, the impact on the strength of the first cover plate 31 can be minimized when the capillary channel 35 is formed. The capillary channel 35 does not need to occupy additional space on the first cover plate 31. This reduces the possibility that opening the capillary channel 35 on the first cover plate 31 would occupy the structural space of the first cover plate 31, which would be detrimental to the thin and light design of the electronic device 100. On the other hand, it also reduces the possibility that setting the first groove 351 or capillary channel 35 at other positions on the first cover plate 31 would affect the structural strength of the first cover plate 31.

[0121] Similarly, the end face of the second support portion 332 facing the first cover plate 31 is recessed to form the second groove 352. The formation of the second groove 352 can easily reduce the strength of the second support portion 332. Therefore, by providing the second groove 352 on the end face of the second support portion 332 away from the second cover plate 32, the impact on the strength of the second cover plate 32 can be minimized when it is used to form the capillary channel 35. Furthermore, since the first cover plate 31 has a partial structure of the capillary channel 35 (i.e., the first groove 351) and the second cover plate 32 has a partial structure of the capillary channel 35 (i.e., the second groove 352), the capillary channel 35 is not completely provided on the first cover plate 31 or the second cover plate 32. The first cover plate 31 and the second cover plate 32 can respectively bear the strength reduction caused by the formation of the capillary channel 35, so that the structural strength of the first cover plate 31 and the second cover plate 32 is relatively balanced.

[0122] In some embodiments, the support structure 33 on the first cover plate 31 and the support structure 33 on the second cover plate 32 can be symmetrically arranged so that when the first cover plate 31 and the second cover plate 32 are sealed together along the first direction X, the first interval 341 and the second interval 342 can correspond to each other, and the first groove 351 and the second groove 352 can correspond to each other.

[0123] Referring to Figures 4 and 5, the first support portion 331 may include a plurality of first grooves 351. The second support portion 332 may include a plurality of second grooves 352. The first grooves 351 and the second grooves 352 correspond one-to-one to form a plurality of capillary channels 35 on the support structure 33.

[0124] The capillary channels 35 can be used to circulate the liquid cooling medium. By setting multiple capillary channels 35, the flow burden of the liquid cooling medium can be distributed, increasing the flow rate of the liquid cooling medium. Furthermore, by setting multiple capillary channels 35, the liquid cooling medium can also flow from different areas away from the heat source 5 towards the heat source 5, which helps to improve the uniformity of the liquid cooling medium flow.

[0125] The capillary channel 35 is a smaller channel structure than the vapor channel 34, allowing the liquid cooling medium to have better capillary force, thereby enabling the cooling medium to flow along the capillary channel 35 towards the heat source 5 under the action of capillary force. When there are multiple capillary channels 35, multiple first grooves 351 can be arranged side by side on the end face of the first support 331 facing the second cover plate 32, and second grooves 352 corresponding to the multiple first grooves 351 are also arranged side by side on the end face of the second support 332 facing the first cover plate 31. Because the capillary channel 35 is a small channel structure, the dimensions of the first grooves 351 and the second grooves 352 are also small, and the impact on the structural strength of the first support 331 and the second support 332 is also small.

[0126] For example, each first support portion 331 is provided with 3 to 8 first grooves 351. The number of first grooves 351 provided on each first support portion 331 can be equal. The number of first grooves 351 provided on each first support portion 331 can also be unequal. No specific limitation is made in the embodiments of this application.

[0127] The extension paths of the steam channel 34 and the capillary channel 35 are not particularly limited in this embodiment. For example, one end of the steam channel 34 may be located in the region corresponding to the heat source 5, and the other end of the steam channel 34 may be located in a region away from the heat source 5. One end of the capillary channel 35 may be located in the region corresponding to the heat source 5, and the other end of the capillary channel 35 may be located in a region away from the heat source 5.

[0128] Figure 6 shows a top view of the first cover plate 31 of a heat spreader 3 according to an embodiment of this application. Figure 7 is a partially enlarged view of point A in Figure 6. It should be noted that, due to the large number of first channels, only the first support portion 331 is shown in Figure 6 for clarity. The first channels are located within the first support portion 331, and are represented by dashed lines.

[0129] Referring to Figures 6 and 7, the support structure 33 may be provided with multiple through holes 36a for connecting multiple capillary channels 35, and the multiple through holes 36a may also be used to connect the capillary channels 35 and the steam channel 34.

[0130] The through-hole 36a allows the capillary channels 35 to be interconnected, thereby increasing the circulation rate of the liquid cooling medium and improving heat dissipation efficiency. Furthermore, the through-hole 36a can also connect the capillary channels 35 and the vapor channel 34, allowing the vapor cooling medium to enter the vapor channel 34 through the through-hole 36a and flow from the vapor channel 34 to the low-temperature region when vaporization occurs in the high-temperature region of the capillary channel 35.

[0131] Referring to the direction shown in Figure 7, within a local area of ​​the heat spreader 3, both the steam channel 34 and the capillary channel 35 can extend along the P direction; that is, the first groove 351 and the first interval 341 can extend along the P direction. The steam channel 34 and the multiple capillary channels 35 are arranged side by side along the Q direction. In other words, the first groove 351 and the first interval 341 are arranged side by side along the Q direction. Multiple through holes 36a can be provided on the area of ​​two adjacent capillary channels 35 on the support structure 33 to connect the two adjacent capillary channels 35.

[0132] Referring again to the direction shown in Figure 7, a first partition 36 is provided between two adjacent first grooves 351 on the first support portion 331. Alternatively, a second partition (not shown) may be provided between two adjacent second grooves 352 on the second support portion 332. A through hole 36a may be provided on at least one of the first partition 36 and the second partition. Taking the first partition 36 having a through hole 36a as an example, the extending direction of the first partition 36 may be the same as the extending direction P of the first groove 351. Along the extending direction P of the first groove 351, a plurality of through holes 36a may be provided at intervals on the first partition 36. Two adjacent first grooves 351 can be connected through the plurality of through holes 36a. Alternatively, the first groove 351 and the steam passage 34 adjacent to the first groove 351 can be connected through the plurality of through holes 36a.

[0133] The liquid cooling medium within the capillary channel 35 can absorb heat from the heat source 5 and vaporize within the region corresponding to the heat source 5, forming a gaseous cooling medium. The gaseous cooling medium can flow from the capillary channel 35 toward the vapor channel 34 near the capillary channel 35, thereby allowing the gaseous cooling medium to enter the vapor channel 34 and flow away from the heat source 5.

[0134] For example, Figure 7 shows that one of the first support portions 331 has three first grooves 351. A first interval 341 is provided on each side of the first support portion 331. A first partition 36 is provided between each of the three first grooves 351. Multiple through holes 36a are provided along the extending direction P of the first partition 36. In Figure 7, the gaseous cooling medium generated by the vaporization reaction in the first groove 351 on the left can flow to the left to enter the first interval 341 on the left; the gaseous cooling medium generated by the vaporization reaction in the first groove 351 on the right can flow to the right to enter the first interval 341 on the right; and the gaseous cooling medium generated by the vaporization reaction in the first groove 351 in the middle can first enter the adjacent first grooves 351 on the left and right sides, and then enter the first interval 341 on the left or right.

[0135] In some embodiments, the through hole 36a can divide the first partition 36 into multiple rectangular structures or "S"-shaped structures to prevent the first channel and the second channel from nesting when the first cover plate 31 and the second cover plate 32 are misaligned, thus avoiding the first cover plate 31 and the second cover plate 32 from being recessed.

[0136] Figure 8 shows an exploded view of a heat spreader 3 according to an embodiment of this application. The heat spreader 3 shown in Figure 8 may have one heat source 5. Figure 9 shows an exploded view of another heat spreader 3 according to an embodiment of this application. The heat spreader 3 shown in Figure 9 may have two heat sources 5.

[0137] Referring to Figures 8 and 9, the heat spreader 3 has a high-temperature region M and a low-temperature region. The high-temperature region M corresponds to the heat source 5, and the low-temperature region is away from the heat source 5. The low-temperature region can refer to the edge region in Figures 8 and 9. One end of the capillary channel 35 can be located in the high-temperature region, and one end of the steam channel 34 can be located in the low-temperature region.

[0138] It is understandable that the area on the heat spreader 3 corresponding to the heat source 5 has a higher temperature; that is, the area on the heat spreader 3 corresponding to the heat source 5 is the high-temperature region M. The liquid cooling medium can vaporize in the high-temperature region M. The vaporized cooling medium can enter the steam channel 34 and flow from the steam channel 34 to the low-temperature region away from the heat source 5. Referring to Figure 3, when the heat source 5 is close to the edge of the heat spreader 3, the low-temperature region can refer to other edge regions on the heat spreader 3 away from the heat source 5. The vaporized cooling medium can liquefy upon cooling in the low-temperature region. The liquid cooling medium formed by the liquefaction can re-enter the high-temperature region M through the capillary channel 35 to dissipate heat from the heat source 5 again.

[0139] Therefore, when there are multiple capillary channels 35, one end of each capillary channel 35 is located within the high-temperature region M. The liquid-phase cooling medium formed by liquefaction in the low-temperature region can be introduced into the high-temperature region M, so that the cooling medium can be concentrated in the high-temperature region M, thereby improving the heat dissipation efficiency of the heat source 5. When there are multiple steam channels 34, one end of each steam channel 34 is located within the low-temperature region. This allows the gaseous cooling medium generated by vaporization to undergo a complete liquefaction reaction in the low-temperature region to form a liquid-phase cooling medium, thereby improving the recycling rate of the cooling medium.

[0140] Referring to Figure 9, when there are two heat sources 5, the heat spreader 3 can have two high-temperature regions M. One end of a portion of the capillary channel 35 can be located in one of the high-temperature regions M, and one end of another portion of the capillary channel 35 can be located in the other high-temperature region M, so as to dissipate heat from the two high-temperature regions M.

[0141] The high-temperature region M on the heat spreader 3 corresponds to the heat source 5. By determining the position of the heat source 5 on the heat spreader 3, the structure and end positions of the steam channel 34 and capillary channel 35 within the heat spreader 3 can be set.

[0142] Referring to Figure 6, the support structure 33 may include an outer channel 37. The outer channel 37 may surround the capillary channel 35 and the steam channel 34, and the outer channel 37 is connected to the capillary channel 35 and the steam channel 34.

[0143] The outer channel 37 can be used to degas the sealed cavity. Degassing refers to evacuating the sealed cavity of the heat spreader 3 to bring it into a state of negative vacuum.

[0144] Since the first support portion 331 and the second support portion 332 abut against each other along the first direction X to form a steam channel 34 and a capillary channel 35, the steam channel 34 and the capillary channel 35 can be arranged side by side on the end faces of the first support portion 331 and the second support portion 332 that abut against each other. Therefore, an outer peripheral channel 37 can be provided on the outer edge of this end face on the heat spreader 3. The steam channel 34 and the capillary channel 35 in the heat spreader 3 are both connected to the outer peripheral channel 37. Therefore, by degassing the outer peripheral channel 37, both the steam channel 34 and the capillary channel 35 can be vacuumed, thereby degassing the entire sealed cavity.

[0145] Referring again to Figure 6, the outer channel 37 can be a steam channel 34. Since the steam channel 34 has a larger internal space than the capillary channel 35, degassing the sealed cavity through the steam channel 34 can effectively improve the degassing efficiency. It should be noted that the outer channel 37 and all steam channels 34 can be interconnected to degas the entire sealed cavity.

[0146] Alternatively, the peripheral channel 37 may include a steam channel 34 and a capillary channel 35. The end of the capillary channel 35 away from the heat source 5 may be located in the peripheral channel 37, so that the ends of the multiple capillary channels 35 away from the heat source 5 are connected in the peripheral channel 37.

[0147] It is easy to understand that the cooling medium in the capillary channel 35, away from the heat source 5, can flow back to the heat source 5 under the action of capillary force, so as to undergo a phase change at the heat source 5. The shorter the path of the capillary channel 35, the larger the flow rate of the cooling medium; the longer the path of the capillary channel 35, the smaller the flow rate of the cooling medium. Therefore, by connecting the ends of multiple capillary channels 35 away from the heat source 5 at the outer channel 37, the flow force of each capillary channel 35 can be freely distributed. For example, the capillary channel 35 with a shorter path can bear more flow force to compensate for the flow force of the capillary channel 35 with a longer path, thereby improving the flow capacity of the cooling medium in the capillary channel 35 to meet the heat dissipation efficiency of the heat source 5.

[0148] It should be noted that this application embodiment does not specifically limit the peripheral channel 37 to be a steam channel 34 or include a capillary channel 35. It can be configured according to the position of the heat source 5 on the heat spreader 3. When degassing efficiency is limited, the peripheral channel 37 can be configured as a steam channel 34 to improve degassing efficiency. When it is necessary to improve the reflux capacity of the cooling medium, a capillary channel 35 can be provided on the peripheral channel 37.

[0149] Referring to Figure 5, the width C of the steam channel 34 can be greater than or equal to 0.5 mm and less than or equal to 2.5 mm.

[0150] When the wall thickness of the first cover plate 31 remains constant, the width C of the steam channel 34 is greater than or equal to 0.5 mm, which increases the space of the steam channel 34. Since the increased space of the steam channel 34 reduces the flow resistance of the gaseous cooling medium, the flowability of the gaseous cooling medium can be improved by increasing the internal space of the steam channel 34, thereby improving the heat dissipation efficiency.

[0151] However, when the width C of the steam channel 34 is large, the cavity formed inside the heat spreader 3 is also large, which can easily affect the strength of the heat spreader 3. For example, when the heat spreader 3 is degassing, the inside of the heat spreader 3 is in a negative pressure environment. Therefore, if the strength of the heat spreader 3 is insufficient, it is easy to deform during the degassing process. Furthermore, if the strength of the heat spreader 3 is insufficient, it is difficult for the heat spreader 3 to meet the strength requirements for fixing components such as batteries and circuit boards.

[0152] Therefore, by setting the width C of the steam channel 34 to be greater than or equal to 0.5 mm and less than or equal to 2.5 mm, the steam channel 34 can have a large space while satisfying the structural strength of the heat spreader 3, so as to reduce the flow resistance of the gas phase cooling medium and thus meet the heat dissipation requirements of the heat source 5.

[0153] Referring again to Figure 5, the first cover plate 31 may have a first wall thickness T1 along the first direction X at the first interval 341. The first wall thickness T1 may be greater than or equal to 0.03 mm and may be less than or equal to 0.05 mm.

[0154] The first wall thickness T1 can affect the structural strength of the first cover plate 31. When the first wall thickness T1 is too small, the first cover plate 31 is easily weakened, making it prone to deformation when the heat spreader 3 is degassed or used to fix circuit boards, batteries, or other structures. Therefore, setting the first wall thickness T1 to be greater than or equal to 0.03 mm can effectively solve the above-mentioned technical problem.

[0155] Furthermore, the size of the first wall thickness T1 also affects the space of the steam channel 34. When the thickness of the heat spreader 3 remains constant, if the size of the first wall thickness T1 is set to be large, the first wall thickness T1 will occupy the space of the steam channel 34 along the first direction X, resulting in a reduction in the internal space of the steam channel 34. Since a smaller space in the steam channel 34 can easily lead to an increase in the flow resistance of the gaseous cooling medium, thus affecting the heat dissipation effect, the above-mentioned technical problem can be effectively solved by setting the first wall thickness T1 to be less than or equal to 0.05 mm.

[0156] Therefore, by setting the first wall thickness T1 to be greater than or equal to 0.03 mm and less than or equal to 0.05 mm, the steam channel 34 can have a larger space while satisfying the structural strength of the heat spreader 3, so as to reduce the flow resistance of the gas phase cooling medium and thus meet the heat dissipation requirements of the heat source 5.

[0157] It should be noted that the width C of the steam channel 34 and the dimensions of the first wall thickness T1 and the second wall thickness T2 can affect the structural strength of the heat spreader 3 and the space of the steam channel 34 inside the heat spreader 3. Therefore, when the width C of the steam channel 34 is small, the sealing cavity inside the heat spreader 3 is smaller, and the structural strength of the heat spreader 3 is better. Thus, the space of the sealing cavity can be increased by reducing the dimensions of the first wall thickness T1 and the second wall thickness T2. For example, when the width C of the steam channel 34 is 0.5 mm, both the first wall thickness T1 and the second wall thickness T2 can be 0.03 mm. Similarly, when the width C of the steam channel 34 is large, the dimensions of the first wall thickness T1 and the second wall thickness T2 are smaller, and the internal space of the steam channel 34 is larger, which can have better heat dissipation efficiency. Therefore, the dimensions of the first wall thickness T1 and the second wall thickness T2 can be increased to meet the structural strength requirements of the heat spreader 3. For example, when the width C of the steam channel 34 is 2.5 mm, both the first wall thickness T1 and the second wall thickness T2 can be 0.05 mm.

[0158] Referring to Figure 5, the width C of the capillary channel 35 is greater than or equal to 0.05 mm and less than or equal to 0.12 mm, the width D2 of the first support portion 331 along the first direction X is greater than or equal to 0.35 mm and less than or equal to 2.04 mm, and the width D2 of the second support portion 332 along the first direction X is greater than or equal to 0.35 mm and less than or equal to 2.04 mm.

[0159] When the width C of the capillary channel 35 is too small, for example, when the width C of the capillary channel 35 is less than 0.05 mm, it easily affects the flow rate of the liquid cooling medium, thus easily affecting the heat dissipation efficiency of the heat source 5. When the width C of the capillary channel 35 is too large, for example, when the width C of the capillary channel 35 is greater than 0.12 mm, it easily leads to an increase in the meniscus radius of the cooling medium within the capillary channel 35. Here, the meniscus refers to the interface shape of the cooling medium within the capillary channel 35. An increase in the meniscus radius of the cooling medium leads to a decrease in capillary force, which in turn slows down the circulation speed of the liquid cooling medium within the heat exchanger 3, resulting in a decrease in heat transfer efficiency. Therefore, the heat exchanger 3 cannot quickly transfer the heat from the heat source 5 to the low-temperature region, leading to overheating of the electronic device 100 and affecting the normal operation of the electronic device 100. Therefore, by setting the width C of the capillary channel 35 to be greater than or equal to 0.05 mm and less than or equal to 0.12 mm, the above-mentioned technical problems can be effectively solved.

[0160] For example, when there are 3 capillary channels 35, the width D1 of the first support portion 331 can be 0.35 mm. The width D2 of the second support portion 332 can be equal to the width D1 of the first support portion 331, that is, the width D2 of the second support portion 332 can also be 0.35 mm. When there are 8 capillary channels 35, the width D1 of the first support portion 331 can be 2.04 mm. The width D2 of the second support portion 332 can be equal to the width D1 of the first support portion 331, that is, the width D2 of the second support portion 332 can also be 2.04 mm.

[0161] Referring to Figure 5, in the first cover plate 31, the depth of the first groove 351 can be L1. The width of the first groove 351 can be B1. Therefore, the depth-to-width ratio L1 / B2 of the first groove 351 can be greater than or equal to 0.5 mm and less than or equal to 0.8 mm.

[0162] The aspect ratio of the first groove 351 can affect capillary force and the flow performance of the cooling medium. When the aspect ratio of the first groove 351 is small, the capacity of the first groove 351 to hold the cooling medium is small, which can easily affect the heat dissipation efficiency of the heat source 5. When the aspect ratio of the first groove 351 is large, since the deeper channel can provide a larger surface area to generate capillary action, the larger aspect ratio of the first groove 351 can increase the capillary force of the capillary channel 35.

[0163] However, when the aspect ratio of the first groove 351 is too large, it will increase the flow resistance of the liquid cooling medium in the capillary channel 35. This is especially true when the viscosity of the cooling medium is high or when the capillary channel 35 has a long flow path, where the impact on the flow resistance of the cooling medium is more significant. Therefore, when the aspect ratio of the first groove 351 is in the range of 0.5 mm to 0.8 mm, the heat dissipation efficiency of the heat source 5 can be satisfied while meeting the flow performance requirements of the cooling medium.

[0164] In the second cover plate 32, the depth of the second groove 352 can be L2. The width of the second groove 352 can be B2. Therefore, the depth-to-width ratio L2 / B2 of the second groove 352 can be greater than or equal to 0.5 mm and less than or equal to 0.8 mm.

[0165] Similarly, the aspect ratio of the second groove 352 can also affect capillary force and the flow properties of the cooling medium. The range of the aspect ratio of the second groove 352 can be the same as the range of the aspect ratio of the first groove 351. This will not be elaborated further in this embodiment.

[0166] Referring again to Figure 5, the first trench 351 and the second trench 352 can have the same structure, and the first trench 351 and the second trench 352 can have the same aspect ratio.

[0167] The first groove 351 and the second groove 352 are opposite to form a capillary channel 35. The cross-sectional shape of the capillary channel 35 can be square, quadrilateral, polygonal, etc. For example, the capillary channel 35 can be elliptical, rhomboid, etc.

[0168] A first passivation film may be provided on the first cover plate 31, and the thickness of the first passivation film may be between 5 nm and 100 nm. A second passivation film may be provided on the second cover plate 32, and the thickness of the second passivation film may be between 5 nm and 100 nm.

[0169] Since the capillary channel 35 formed by the first cover plate 31 and the second cover plate 32 can be used to contain the liquid phase cooling medium, and the vapor channel 34 formed by the first cover plate 31 and the second cover plate 32 can be used to contain the gas phase cooling medium, the first cover plate 31 and the second cover plate 32 are susceptible to oxidation, corrosion, and other effects. A first passivation film can form a stable protective layer on the surface of the first cover plate 31 to reduce the possibility of corrosion by the cooling medium. Similarly, a second passivation film can form a stable protective layer on the surface of the second cover plate 32 to reduce the possibility of corrosion by the cooling medium, thereby improving the working performance and service life of the heat spreader 3.

[0170] In some embodiments, chemical passivation treatment can be performed on the first cover plate 31 and the second cover plate 32 to form a first passivation film and a second passivation film on the first cover plate 31 and the second cover plate 32, respectively.

[0171] The capillary channel 35 may have microstructures protruding or recessed into its inner wall. Forming microstructures on the inner wall of the capillary channel 35 can enhance hydrophilicity and water retention.

[0172] The microstructure of the inner wall of the capillary channel 35 promotes the uniform distribution of the cooling medium throughout the entire capillary channel 35, preventing localized drying or excessive wetting of the inner wall and enhancing hydrophilicity. This improves the adsorption capacity between the cooling medium and the capillary channel 35, allowing the cooling medium to remain within the capillary channel 35 and increasing water retention. Furthermore, the microstructure increases the surface area within the capillary channel 35, thereby enhancing capillary force and facilitating more efficient flow of the cooling medium within the channel. The microstructure also increases the contact area between the liquid and the channel wall, thus improving heat transfer efficiency.

[0173] The microstructure can be a protruding structure or a recessed structure, and it can be an irregular shape. No specific limitation is made in this embodiment. For example, the microstructure can be a microporous structure, a microgroove structure, etc.

[0174] The specific shape of the microstructure is not specifically limited in the embodiments of this application. The size of the microstructure can be between 1 nm and 1 μm.

[0175] This application also provides a method for manufacturing a heat spreader 3, used to prepare a heat spreader 3 as described in any of the above claims. The manufacturing method includes:

[0176] Step S1: A first gap 341 and a first groove 351 are formed on the first cover plate 31, and a second gap 342 and a second groove 352 are formed on the second cover plate 32;

[0177] Step S2: Perform chemical passivation treatment on the first cover plate 31 and the second cover plate 32 to form a first passivation film on the first cover plate 31 and a second passivation film on the second cover plate 32.

[0178] Step S3: Roughen the first cover plate 31 and the second cover plate 32 to form microstructures on the inner walls of the first cover plate 31 and the second cover plate 32.

[0179] Step S4: Seal the first cover plate 31 and the second cover plate 32 together so that the first interval 341 and the second interval 342 form a steam channel 34, and the first groove 351 and the second groove 352 form a capillary channel 35.

[0180] In step S1, a first gap 341 and a first trench 351 are formed on the first cover plate 31, specifically through processes such as etching or laser ablation. Taking etching as an example, the first gap 341 can be formed by etching the surface of the first cover plate 31 facing the second cover plate 32. A first support portion 331 is formed between two adjacent first gaps 341. The first trench 351 can be formed on the first support portion 331 through processes such as etching or laser ablation. Similarly, a second gap 342 and a second trench 352 are formed on the second cover plate 32, specifically through processes such as etching or laser ablation. Taking etching as an example, the second gap 342 can be formed by etching the surface of the second cover plate 32 facing the first cover plate 31. A second support portion 332 is formed between two adjacent second gaps 342. The second trench 352 can be formed on the second support portion 332 through processes such as etching or laser ablation.

[0181] In step S2, a passivation solution can be used to passivate the first cover plate 31 and the second cover plate 32. The passivation solution is a hydrogen peroxide aqueous solution with a mass fraction between 0.5% and 3%. The passivation treatment time is 10 min to 2 h. The passivation treatment temperature is 20℃ to 60℃.

[0182] In step S3, the roughening treatment refers to roughening the inner walls of the first cover plate 31 and the second cover plate 32 to form microstructures in the first groove 351 and the second groove 352, so that when the first cover plate 31 and the second cover plate 32 are sealed together, microstructures can be formed on the inner walls of the capillary channel 35 formed by the first groove 351 and the second groove 352.

[0183] The first cover plate 31 and the second cover plate 32 can be roughened using a roughening solution, which can be an aqueous solution containing FeCl3, H2SO4, and H2O2. The concentration of FeCl3 is 10-60 g / L, the concentration of H2SO4 is 30-50 g / L, and the concentration of H2O2 is 100-150 ml / L. The roughening treatment time is 20-60 minutes, and the roughening treatment temperature is 40-65℃.

[0184] In step S4, when the first cover plate 31 and the second cover plate 32 are sealed together, the first support portion 331 and the second support portion 332 abut against each other. The first cover plate 31 and the second cover plate 32 can be sealed together by laser welding to form a steam channel 34 and a sealing channel.

[0185] After step S4, the first cover plate 31 and the second cover plate 32 can be subjected to baking activation treatment. The baking activation temperature is 150℃-400℃, the baking activation time is 10min-2h, and the atmosphere is nitrogen.

[0186] Baking activation treatment can be used to remove residual chemical passivation solution from the chemical passivation process. On the one hand, residual chemical passivation solution may form uneven film or deposits inside the heat spreader 3, affecting heat conduction performance. On the other hand, the chemical components in the passivation solution may react with the cooling medium inside the heat spreader 3, leading to the formation of unstable byproducts, which can easily affect the heat dissipation performance of the heat spreader 3.

[0187] Baking activation provides sufficient activation energy by heating the heat spreader 3, enabling the polar groups on the microstructure surface of the capillary channel 35's inner wall to overcome the energy barrier. These polar groups are highly hydrophilic and can form hydrogen bonds with water molecules in the cooling medium, significantly improving the wettability of the capillary channel 35's surface. These polar groups can be oxygen- or nitrogen-containing chemical groups, such as hydroxyl groups (-OH). Therefore, by heating the heat spreader 3 to a certain temperature, these polar groups can be released from the surface, causing the microstructure surface of the capillary channel 35 to exhibit a superhydrophilic state.

[0188] Baking activation treatment can enhance the hydrophilicity and capillary force of capillary channels 35, thus effectively improving the water retention of heat spreader 3, enabling liquid to be more effectively adsorbed and retained in capillary channels 35, promoting uniform distribution and rapid reflux of cooling medium, thereby improving the overall thermal conductivity and stability of heat spreader 3.

[0189] In this embodiment, by precisely controlling the temperature, time, and environment of the baking and activation process, the optimal water retention effect can be achieved, ensuring the efficient operation of the heat spreader 3.

[0190] It should be noted that, since the first cover plate 31 and the second cover plate 32 are sealed together by laser welding and other processes, the parts of the first cover plate 31 and the second cover plate 32 affected by thermal stress are prone to passivation failure in some areas of the first passivation film and the second passivation film. Therefore, after step S4, a secondary chemical passivation treatment can be performed on the heat spreader 3 to ensure the integrity of the first passivation film and the second passivation film on the first cover plate 31 and the second cover plate 32, and reduce the possibility of local failure affecting the performance of the heat spreader 3.

[0191] After the baking and activation process is completed, subsequent steps such as water injection, first removal, second removal, and sealing can be carried out.

[0192] Water injection can refer to injecting cooling medium into the sealed cavity. First and second degassing refer to degassing the sealed cavity separately to bring it into a vacuum state.

[0193] By degassing the sealed cavity formed by the first cover plate 31 and the second cover plate 32, the sealed cavity can be placed in a vacuum negative pressure environment. Specifically, the degassing process can be as follows: since the peripheral air passages are connected to all the vapor channels 34 and capillary channels 35 within the heat spreader 3, a degassing needle can be inserted through the degassing port of the heat spreader 3 into the peripheral air passages to degas the sealed space inside the heat spreader 3. Then, a vacuum pump can be used to degas the peripheral air passages of the heat spreader 3 using the degassing needle.

[0194] In some embodiments, the heat spreader 3 can be heated during the degassing process to promote the release and discharge of air from the sealed cavity of the heat spreader 3, thereby improving the degassing efficiency.

[0195] In some embodiments, the water inlet can be located at any position on the heat spreader 3. When the heat spreader 3 is applied to a foldable electronic device 100 (e.g., a foldable mobile phone), since the left side of the electronic device 100 is provided with a folding hinge and the right side can be provided with a circuit board, the water inlet can be located on the heat spreader 3 near the top or bottom.

[0196] After completing the above degassing process, the heat spreader 3 needs to be cooled and sealed. Cooling the heat spreader 3 means stopping heating it, allowing it to gradually cool to room temperature. During the cooling process, the interior of the heat spreader 3 remains under vacuum to prevent external air from re-entering. Sealing the heat spreader 3 refers to sealing the degassing port. This sealing can be achieved using processes such as welding.

[0197] This application also provides an electronic device 100. The electronic device 100 may include a heat source 5, a heat spreader 3, and a middle frame 1. The heat source 5 and the heat spreader 3 can be securely connected by fasteners. The heat spreader 3 and the middle frame 1 can be sealed together by adhesive dispensing.

[0198] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0199] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Claims

1. A heat spreader (3), characterized in that, include: First cover plate (31); The second cover plate (32) is connected to the first cover plate (31) and forms a sealed cavity; A support structure (33) is located in the sealed cavity. The support structure (33) connects the first cover plate (31) and the second cover plate (32). The support structure (33) divides the sealed cavity into at least two channels, wherein at least one of the channels is a steam channel (34) and at least one of the channels is a capillary channel (35). The steam channel (34) and the capillary channel (35) are connected.

2. The heat spreader (3) according to claim 1, characterized in that, At least one of the first cover plate (31) and the second cover plate (32) is provided with the support structure (33).

3. The heat spreader (3) according to claim 1 or 2, characterized in that, The support structure (33) includes a first support part (331) and a second support part (332), wherein the first support part (331) is disposed on the first cover plate (31) and the second support part (332) is disposed on the second cover plate (32); There are multiple first support portions (331), and a first interval (341) is formed between two adjacent first support portions (331); There are multiple second support portions (332), and a second interval (342) is formed between two adjacent second support portions (332); The first support portion (331) and the second support portion (332) abut against each other, and the first interval (341) and the second interval (342) are connected to form the steam passage (34).

4. The heat spreader (3) according to claim 3, characterized in that, The first support portion (331) has a first groove (351) on its end face facing the second support portion (332), and the second support portion (332) has a second groove (352) on its end face facing the first support portion (331). When the first support portion (331) and the second support portion (332) abut against each other, the first groove (351) and the second groove (352) form the capillary channel (35).

5. The heat spreader (3) according to claim 4, characterized in that, Along the first direction, the first support portion (331) includes a plurality of first grooves (351), and the second support portion (332) includes a plurality of second grooves (352), with the first grooves (351) and the second grooves (352) corresponding one-to-one to form a plurality of capillary channels (35) on the support structure (33).

6. The heat spreader (3) according to any one of claims 1 to 5, characterized in that, The support structure (33) is provided with a plurality of through holes (36a) for connecting a plurality of capillary channels (35), and the plurality of through holes (36a) connect the capillary channels (35) and the steam channel (34).

7. The heat spreader (3) according to any one of claims 1 to 6, characterized in that, The heat spreader (3) has a high-temperature region and a low-temperature region, the high-temperature region being opposite to the heat source and the low-temperature region being away from the heat source; One end of the capillary channel (35) is located in the high-temperature region, and one end of the steam channel (34) is located in the low-temperature region.

8. The heat spreader (3) according to any one of claims 1 to 7, characterized in that, The support structure (33) includes an outer channel (37) which surrounds the capillary channel (35) and the steam channel (34) and is connected to the capillary channel (35) and the steam channel (34).

9. The heat spreader (3) according to claim 8, characterized in that, The peripheral channel (37) is the steam channel (34); or, the peripheral channel (37) includes the steam channel (34) and the capillary channel (35).

10. The heat spreader (3) according to any one of claims 1 to 9, characterized in that, The width of the steam channel (34) is greater than or equal to 0.5 mm and less than or equal to 2.5 mm.

11. The heat spreader (3) according to claim 3, characterized in that, The first cover plate (31) has a first wall thickness along a first direction at the first interval (341), the first wall thickness being greater than or equal to 0.03 mm and less than or equal to 0.05 mm; And / or, the second cover plate (32) has a second wall thickness in the steam passage (34) along the first direction, the second wall thickness being greater than or equal to 0.03 mm and less than or equal to 0.05 mm.

12. The heat spreader (3) according to claim 3, characterized in that, The width of the capillary channel (35) is greater than or equal to 0.05 mm and less than or equal to 0.12 mm, the width of the first support portion (331) along the first direction is greater than or equal to 0.35 mm and less than or equal to 2.04 mm, and the width of the second support portion (332) along the first direction is greater than or equal to 0.35 mm and less than or equal to 2.04 mm.

13. The heat spreader (3) according to claim 4, characterized in that, In the first cover plate (31), the depth of the first groove (351) is L1, the width of the first groove (351) is B1, and the depth-to-width ratio of the first groove (351) L1 / B1 is greater than or equal to 0.5 mm and less than or equal to 0.8 mm.

14. The heat spreader (3) according to claim 4, characterized in that, In the second cover plate (32), the depth of the second groove (352) is L2, the width of the first groove (351) is B2, and the depth-to-width ratio of the second groove (352) L1 / B1 is greater than or equal to 0.5 mm and less than or equal to 0.8 mm.

15. The heat spreader (3) according to any one of claims 1 to 14, characterized in that, The first cover plate (31) is provided with a first passivation film, the thickness of which is between 5nm and 100nm; The second cover plate (32) is provided with a second passivation film, the thickness of which is between 5nm and 100nm.

16. The heat spreader (3) according to any one of claims 1 to 14, characterized in that, The capillary channel (35) is provided with microstructures that protrude or are recessed into the inner wall of the capillary channel (35).

17. A method for manufacturing a heat spreader, characterized in that, The method for manufacturing a heat spreader as described in any one of claims 1 to 16 includes: A first gap and a first groove are formed on a first cover plate, and a second gap and a second groove are formed on a second cover plate; The first cover plate and the second cover plate are chemically passivated to form a first passivation film on the first cover plate and a second passivation film on the second cover plate. The first cover plate and the second cover plate are roughened to form microstructures on the inner walls of the first cover plate and the second cover plate opposite to each other; The first cover plate and the second cover plate are sealed together so that the first gap and the second gap form a steam channel, and the first groove and the second groove form a capillary channel.

18. The manufacturing method according to claim 17, characterized in that, The chemical passivation treatment of the first cover plate and the second cover plate to form a first passivation film on the first cover plate and a second passivation film on the second cover plate includes: The first cover plate and the second cover plate are passivated using a passivation solution, which is a hydrogen peroxide aqueous solution with a mass fraction between 0.5% and 3%. The passivation treatment time is 10 min to 2 h, and the passivation treatment temperature is 20℃ to 60℃.

19. The manufacturing method according to claim 17, characterized in that, The roughening treatment of the first cover plate and the second cover plate to form microstructures on the opposing inner walls of the first cover plate and the second cover plate includes: The first cover plate and the second cover plate are roughened using a roughening solution, wherein the roughening solution is an aqueous solution containing FeCl3, H2SO4 and H2O2; The concentrations of FeCl3, H2SO4, and H2O2 were 10-60 g / L, 30-50 g / L, 100-150 ml / L, respectively. The roughening treatment time was 20-60 min, and the roughening treatment temperature was 40-65℃.

20. The manufacturing method according to claim 17, characterized in that, After roughening the first cover plate and the second cover plate to form microstructures on the opposing inner walls of the first cover plate and the second cover plate, the process further includes: The first cover plate and the second cover plate are baked and activated; The baking and activation temperature is 150℃-400℃, the baking and activation time is 10min-2h, and the atmosphere is nitrogen.

21. An electronic device (100), characterized in that, include: Heat source (5) ； The heat spreader (3) as described in any one of claims 1 to 16, wherein the heat source (5) is disposed on the heat spreader (3); The middle frame (1) is sealed to the heat spreader (3).

Images