Vapor chamber with high-temperature-uniformity bending structure and processing method of vapor chamber

Abstract

The invention relates to a vapor chamber with a high-temperature-uniformity bending structure and a machining method thereof.The vapor chamber structurally comprises a shell, a bending area is arranged on the inner surface and / or the outer surface of the shell, a plurality of grooves are formed in the bending area, and the machining method comprises the following steps that a plate shell needing to be provided with the grooves is prepared, and the surface is cleaned; the bending area is coated with photoresist; exposing and developing the surface coated with the photoresist through a mold; and performing chemical etching or laser processing to form a groove. The vapor chamber can solve the use problems that the temperature of a bending area is high when the vapor chamber works due to collapse compression of a steam channel and blocking of the heat transfer process under the bending condition, and the good temperature equalizing performance cannot be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of vapor chambers, and in particular to a vapor chamber with a high temperature uniformity bending structure and a processing method thereof. Background Art

[0002] With the emergence and rapid development of the fifth generation of mobile communication technology (5G technology), electronic products, especially smartphones, tablets and other products, are increasingly moving towards high performance, high integration and miniaturization. Taking mobile phones as an example, the full load power consumption has increased from the initial 1W to more than 5W, and may even reach 15W in the future. Therefore, for portable electronic devices, it has become a common and urgent need to develop a heat dissipation method that can handle high heat dissipation power in an extremely narrow space (<1mm).

[0003] Ultra-thin vapor chambers are self-driven, have high equivalent thermal conductivity, are lightweight, and have compact structures. They are widely used to dissipate heat from electronic components in narrow spaces. However, when faced with some complex working environments, conventional flat-type ultra-thin vapor chambers will face the test of performance degradation, such as folding-screen mobile phones and folding-screen laptops. Therefore, optimizing the ultra-thin vapor chamber shell structure has become a key factor in improving the service life of ultra-thin flat heat pipes.

[0004] At present, the shell structure used by the ultra-thin heat spreader is a conventional planar type. However, under bending conditions, due to the collapse and compression of the steam channel, the heat transfer process is hindered, which will cause the temperature of the heat spreader at the bend to be higher during operation, and good temperature uniformity performance cannot be guaranteed. Summary of the invention

[0005] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to propose a heat spreader with a high temperature uniformity bending structure and a processing method thereof, which can solve the problem that under bending conditions, the temperature of the bending zone of the heat spreader is high during operation due to the collapse and compression of the steam channel and the obstruction of the heat transfer process, and good temperature uniformity performance cannot be guaranteed.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The present invention provides a heat spreader with a high temperature uniformity bending structure, comprising a shell, wherein a bending area is arranged on the inner surface and / or the outer surface of the shell, and a plurality of grooves are opened on the bending area.

[0008] A preferred technical solution of the present invention is that the cross-sectional shape of the groove is trapezoidal.

[0009] A preferred technical solution of the present invention is that a plurality of support columns are arranged inside the shell, and the support columns are located inside the bending area.

[0010] A preferred technical solution of the present invention is that a rough layer is provided on the surface of the groove.

[0011] A preferred technical solution of the present invention is that a heat conducting layer is provided on the surface of the groove.

[0012] A preferred technical solution of the present invention is that the distance between adjacent grooves is 0.02-0.1 mm.

[0013] A preferred technical solution of the present invention is that the shell comprises an outer shell and an inner shell, the groove is provided on the outer shell and / or the inner shell, and the depth of the groove is 10%-50% of the minimum thickness of the outer shell and / or the inner shell.

[0014] The present invention provides a method for processing a heat spreader with a high temperature uniformity bending structure, comprising the following steps:

[0015] S0, prepare the plate and shell where grooves need to be opened and clean the surface;

[0016] S1, coating photoresist on the bending area;

[0017] S2, exposing and developing the surface coated with the photoresist through the mold;

[0018] S3, chemical etching or laser processing to form grooves.

[0019] A preferred technical solution of the present invention is that it further comprises S4, performing surface treatment on the groove to increase the surface roughness.

[0020] A preferred technical solution of the present invention is that the surface treatment is chemical oxidation treatment.

[0021] Beneficial effects of the present invention:

[0022] The present invention proposes a heat spreader with a high temperature uniformity bending structure and a processing method thereof. By setting a groove structure on the bending area of ​​the heat spreader, the grooves in the bending area will increase the specific surface area due to tension, thereby enhancing the heat exchange efficiency between the bending area and the external environment. In addition, the groove structure setting can further improve the structural strength distribution of the heat spreader in the bending area and reduce the stress concentration of the material in the bending area. This helps to extend the service life of the heat spreader and reduce fatigue problems caused by long-term use and temperature changes. The structure of the present invention is simple, the assembly requirements are not high, and it can be implemented based on the industrial production of heat spreaders, which is low in cost. Moreover, the processing method of the grooves is simple to operate, the precision requirements of the parts involved are not high, it is easy to process, convenient and practical, and has a wide range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 A three-dimensional diagram of the heat spreader with a high temperature uniformity bending structure in the first embodiment in an unbent state;

[0025] Figure 2 A three-dimensional diagram of a bending state of a heat spreader with a high temperature uniformity bending structure according to the first embodiment;

[0026] Figure 3 for Figure 2 A magnified view of part A;

[0027] Figure 4 It is a schematic diagram of the inner side processing structure of the outer shell of the first embodiment;

[0028] Figure 5 It is a schematic diagram of the process of the processing method of the heat spreader with a high temperature uniformity bending structure according to the first embodiment;

[0029] Figure 6 It is a partial enlarged view of the groove structure of the fourth embodiment;

[0030] Figure 7 This is a schematic diagram of the inner side processing structure of the outer shell of Example 5;

[0031] Figure 8 It is a partial enlarged view of the groove structure of Example 7;

[0032] Fig. 9 This is a partial enlarged view of the groove structure of Example 8.

[0033] In the figure:

[0034] 1-shell; 11-outer shell; 111-inner cavity; 112-welding frame; 12-inner shell; 2-bending area; 3-groove; 4-support column; 5-rough layer; 6-heat conducting layer; 7-non-bending area. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Embodiment 1

[0038] like Figure 1-4 As shown, a heat spreader with a high temperature uniformity bending structure provided in this embodiment includes a shell 1, and a bending area 2 and a non-bending area 7 are arranged on the inner and outer surfaces of the shell 1, and a plurality of grooves 3 are opened on the bending area 2. The working principle of the bending structure is that when the heat spreader is bent and deformed, no matter which side it is bent to, the bending structure on the other side will increase the specific surface area due to tension, thereby enhancing the heat exchange efficiency between the bending area and the external environment. Compared with the traditional structure, this structure improves the heat dissipation capacity of the heat spreader in the bending area, thereby ensuring that the ultra-thin heat spreader still has good temperature uniformity performance under bending conditions. In addition, the groove structure setting on the bending area can further improve the structural strength distribution of the heat spreader in the bending area and reduce the stress concentration of the material in the bending area. This helps to extend the service life of the heat spreader and reduce fatigue problems caused by long-term use and temperature changes.

[0039] Specifically, the cross-sectional shape of the groove is a rectangle. The rectangular shape is relatively simple and easier to process and manufacture. Using a rectangular groove may reduce the complexity of manufacturing, reduce manufacturing costs, and improve production efficiency. This is a very important consideration for large-scale production and large-scale applications. In addition, the rectangular cross-section is easier to maintain structural stability and strength than some complex shapes. In the bending area of ​​the heat spreader, choosing a rectangular shape may be more conducive to reducing stress concentration, ensuring sufficient structural strength during the bending process, and preventing deformation or breakage.

[0040] Preferably, the thickness of the shell 1 is 0.05-1 mm. The thickness of the shell directly affects the thermal conductivity of the heat spreader. A thinner shell generally has better thermal conductivity, which helps to transfer heat more efficiently. On the other hand, a moderate shell thickness can also provide sufficient structural strength without significantly increasing thermal resistance, thereby helping to dissipate heat. In this embodiment, the thickness of the shell 1 is 1 mm.

[0041] Preferably, the distance between adjacent grooves 3 is 0.02-0.1mm. The distance between adjacent grooves is small, which can ensure that the surface area between the grooves is maximized. By increasing the surface area, the heat spreader can absorb or dissipate heat more effectively, improving the overall heat transfer efficiency. However, too small a groove distance may cause problems with mechanical strength. During the manufacturing, assembly and use process, there may be a risk of extrusion, deformation or damage, affecting the long-term reliability of the heat spreader. In this embodiment, 0.05mm is used.

[0042] In order to facilitate processing and assembly, the housing 1 includes an outer housing 11 and an inner housing 12, the inner surface and the outer surface are the outward surfaces of the outer housing 11 and the inner housing 12, respectively, and the groove 3 is provided on the inner surface and the outer surface. Preferably, the depth and width of the groove 3 of the outer housing 11 and the inner housing 12 are 10%-50% of the minimum thickness of the outer housing 11 and the inner housing 12. In this embodiment, the minimum thickness of the outer housing 11 and the inner housing 12 is 0.3 mm, and the depth and width of the groove are 20% of the minimum thickness, that is, the depth and width of the groove are 0.06 mm.

[0043] Preferably, the material of the shell is copper. Copper has excellent thermal conductivity and is an excellent heat dissipation material. By selecting copper as the material of the vertical portion, the left wing portion and the right wing portion, the thermal conductivity of the heat spreader can be effectively improved, promoting more efficient heat transfer. Copper is a material with good plasticity and is easy to process into complex shapes, which helps to achieve a more flexible heat spreader design. This plasticity makes copper easier to process and shape during the manufacturing process.

[0044] The heat sink with a high temperature uniformity bending structure is equipped with a heat dissipation medium, which is deionized water. The heat dissipation medium is deionized water with a resistivity of 18.2MΩ*cm, and the internal vacuum degree is 7Pa after vacuum treatment. After condensation, the heat dissipation medium returns to the evaporation end through the capillary action of the liquid absorption core for the second stage of heat transfer, realizing a thermal cycle inside the system.

[0045] like Figure 5 As shown, the processing method of the heat spreader with a high temperature uniformity bending structure of this embodiment is briefly described as follows:

[0046] The shell of the heat spreader is welded by an outer shell 11 and an inner shell 12. Specifically, take the outer shell 11 as an example: Step 1, prepare the plate shell that needs to be grooved, clean the plate shell with ultrasonic cleaning and dry it; Step 2, divide the bending area, and coat the bending area with photoresist; Step 3, expose the surface coated with photoresist through a mold. The mold used in this embodiment is a mold with multiple rectangular spaced light-transmitting openings, and the bending area is exposed through the mold; Step 4, develop, and the unexposed photoresist is dissolved; Step 5, control the etching depth through chemical etching, and the accuracy is 3um. The inner shell is processed in the same way.

[0047] Then, an inner cavity 111 for arranging a liquid absorbent core is processed on the other side of the outer shell and the inner shell. The inner cavity processing method can be conventional chemical etching or laser processing, and the flexible liquid absorbent core is welded to the inner cavity 111. The outer shell and the inner shell are welded and assembled along the welding frame 112, and then conventional operations such as liquid injection and sealing are performed to make them one body. Among them, the flexible liquid absorbent core can be a general silk screen, a braided belt, and other liquid absorbent cores with strong flexibility. In this embodiment, a metal braided belt treated with chemical corrosion is used. The subsequent process bends the welded heat spreader to the part that needs to be bent, and uses a conventional bending mold to bend the bending area to obtain a heat spreader with a high temperature uniformity bending structure.

[0048] It is noted that the present invention performs additional surface treatment processes after the surface groove structure is processed, including but not limited to spraying high thermal conductivity materials, oxidation treatment, etc. to increase the surface roughness of the micro-groove structure, thereby further increasing its specific surface area and improving the heat dissipation efficiency at the bend. The above embodiment is only one example of the strengthening process, and other methods of increasing the surface roughness of the micro-groove structure are all within the scope of protection.

[0049] The newly added process technology steps increase the processing cost of the vapor chamber to a certain extent, but its structure improves the bending efficiency and performance, reduces the scrap rate in the bending manufacturing process, and thus reduces the manufacturing cost. By improving the overall performance of the vapor chamber, it can be used in a wider range of applications. For example, in electronic equipment, industrial equipment or other heat transfer fields that require high temperature uniformity bending application scenarios.

[0050] Embodiment 2

[0051] The heat spreader with a high temperature uniformity bending structure provided in this embodiment is different from the first embodiment in that the grooves are only provided on the inner surface of the shell. Since the bending area is only provided on the inner surface of the shell, compared with providing the bending area on the inner and outer surfaces of the entire shell, it can save materials and reduce manufacturing costs. Moreover, due to the reduction of grooves, the strength of the overall structure of the bending area is increased, which is suitable for applications where the heat dissipation of the inner surface is enhanced.

[0052] Embodiment 3

[0053] The heat spreader with a high temperature uniformity bending structure provided in this embodiment is different from the first embodiment in that the grooves are only provided on the outer surface of the shell. Since only the outer surface of the shell is provided with a bending area, compared with providing the bending area on the inner and outer surfaces of the entire shell, it can save materials and reduce manufacturing costs. Moreover, due to the reduction of grooves, the strength of the overall structure of the bending area is increased, which is suitable for applications where the heat dissipation of the outer surface is enhanced.

[0054] Embodiment 4

[0055] The heat spreader with a high temperature uniformity bending structure provided in this embodiment is different from the first embodiment in that the cross-sectional shape of the groove 3 is a trapezoid, such as Figure 6 As shown. The trapezoidal cross-section is more likely to reduce stress concentration than some shapes with sharp edges. This helps to improve the structural stability of the heat spreader during operation and reduce the risk of breakage due to stress concentration. In addition, under the same groove volume, the structure of the trapezoidal cross-section has a larger specific surface area. After testing, under the same groove volume, the trapezoidal cross-section heat spreader of Example 2 has a stronger heat dissipation capacity than the rectangular cross-section of Example 1.

[0056] Embodiment 5

[0057] The present embodiment provides a heat spreader with a high temperature uniformity bending structure, which is different from the first embodiment in that a plurality of support columns 4 are arranged inside the shell. Specifically, an inner cavity 111 for arranging a liquid wick and support columns 4 are processed on the other side of the outer shell and the inner shell, and the support columns are located on the inner side of the bending area, such as Figure 7 As shown. The internal support column helps to increase the structural strength of the vapor chamber in the bending area. The support column can effectively disperse external forces or stresses, reduce the structural stress concentration at the bend, and improve the overall structural strength of the vapor chamber. The existence of the support column can slow down or resist the deformation and deformation of the bending area. When the vapor chamber is working, it may be affected by external pressure or force. The support column helps prevent excessive deformation of the bending area and ensure that the vapor chamber maintains its original shape.

[0058] Embodiment 6

[0059] A heat spreader with a high temperature uniformity bending structure provided in this embodiment is different from the first embodiment in that the grooves are formed by laser micromachining technology. Laser micromachining technology has high accuracy and fineness, and can form grooves on a micron scale. This can provide more precise and detailed structures, suitable for applications that require high precision. Compared with chemical etching, laser micromachining does not involve the use of corrosives and chemicals, so it is more environmentally friendly and avoids the problem of chemical pollution. Compared with chemical etching methods, the processing depth of laser micromachining may be subject to certain limitations, which may not be ideal for applications that require deeper grooves.

[0060] Embodiment 7

[0061] The difference between the heat spreader with a high temperature uniformity bending structure provided in this embodiment and the embodiment 1 is that after the grooves are formed by chemical etching, specifically, the bending area is immersed in a sufficient amount of a mixed solution of 2 mol / L NaOH and 0.1 mol / L K2S2O8 at room temperature (20-25°C) for 40 minutes, so that a micro-nano oxide layer structure with high bending strength is generated on its surface, and the oxide layer structure increases the surface roughness of the groove structure, and simultaneously forms a rough layer 5, such as Figure 8 As shown, the specific surface area is further increased, and the heat dissipation efficiency at the bend is further improved.

[0062] Embodiment 8

[0063] The difference between the heat spreader with a high temperature uniformity bending structure provided in this embodiment and the first embodiment is that after the grooves are formed by chemical etching, a high thermal conductivity material is sprayed on the grooves by a spraying process to form a thermal conductive layer 6, such as Fig. 9 As shown. Graphene is used in this embodiment. Graphene has excellent thermal conductivity, and spraying it on the grooves can significantly improve the thermal conductivity of the heat spreader. This helps to transfer heat more efficiently and improve the thermal uniformity of the entire heat spreader. In addition, the graphene film can be applied to the grooves in a relatively thin form, adding almost no additional burden or weight. This is an advantage for applications that require lightweight design.

[0064] The present invention is described through preferred embodiments. Those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features (such as changing the processing depth, processing area, processing width and other parameters of the bending structure) and embodiments without departing from the spirit and scope of the present invention. The present invention is not limited to the specific embodiments disclosed herein, and other embodiments falling within the claims of this application are within the scope of protection of the present invention.

Claims

1. A heat spreader with a high temperature uniformity bending structure, characterized in that: It comprises a shell (1), wherein a bending area (2) is provided on the inner surface and / or the outer surface of the shell (1), and a plurality of grooves (3) are provided on the bending area (2).

2. The heat spreader with a high temperature uniformity bending structure according to claim 1, characterized in that: The cross-sectional shape of the groove (3) is a trapezoid.

3. The heat spreader with a high temperature uniformity bending structure according to claim 1, characterized in that: A plurality of support columns (4) are arranged inside the shell (1), and the support columns (4) are located on the inner side of the bending area (2).

4. The heat spreader with a high temperature uniformity bending structure according to claim 1, characterized in that: The surface of the groove (3) is provided with a rough layer (5).

5. The heat spreader with a high temperature uniformity bending structure according to claim 1, characterized in that: A heat-conducting layer (6) is provided on the surface of the groove (3).

6. The heat spreader with a high temperature uniformity bending structure according to claim 1, characterized in that: The distance between adjacent grooves (3) is 0.02-0.1 mm.

7. The heat spreader with a high temperature uniformity bending structure according to claim 1, characterized in that: The shell (1) comprises an outer shell (11) and an inner shell (12); the groove (3) is provided on the outer shell (11) and / or the inner shell (12); the depth of the groove (3) is 10%-50% of the minimum thickness of the outer shell (11) and / or the inner shell (12).

8. A method for processing a vapor chamber with a high temperature uniformity bending structure according to claims 1-7, characterized in that: The following steps are involved: S0, preparing the plate and shell on which the grooves are to be formed, and cleaning the surface; S1, coating a photoresist on the bending area; S2, exposing and developing the surface coated with the photoresist through the mold; S3, chemical etching or laser processing to form the groove.

9. The processing method according to claim 8, characterized in that: The method further includes S4, performing a surface treatment on the groove to increase the surface roughness.

10. The processing method according to claim 9, characterized in that: The surface treatment is chemical oxidation treatment.

Images