Vapor chamber and manufacturing method thereof

Abstract

The invention discloses a vapor chamber and a manufacturing method thereof. The vapor chamber comprises a plate body with a closed cavity, a capillary structure, at least one supporting structure and working medium fluid. Wherein the whole supporting structure is of a porous structure, and the hole diameter and the porosity of holes contained in the porous structure are increased from inside to outside in the radial direction. Compared with the prior art, the vapor chamber has the advantages that by adopting the supporting structure with the porous structure, the evaporation efficiency and the condensation backflow speed of the working medium fluid in the vapor chamber can be remarkably improved, and therefore the heat dissipation performance of the vapor chamber is greatly improved.

Description

Technical Field

[0001] The present application relates to a heat dissipation device, and in particular to a temperature homogenizing plate and a manufacturing method thereof. Background Art

[0002] Compared with traditional air cooling and liquid cooling, new cooling methods represented by Vapor Chamber (VC) have the advantages of good thermal conductivity, good temperature uniformity, and larger contact area. It has become an important way to solve the heat dissipation of semiconductors and electronic devices.

[0003] The existing temperature equalizer is usually a completely closed flat cavity composed of a base plate, a frame and a cover plate. The inner wall of the cavity is provided with a liquid absorbing capillary core structure. At the same time, a support structure is usually required inside the cavity to overcome the plate depression caused by the vacuum negative pressure and the plate deformation caused by temperature changes. The working principle of the existing temperature equalizer is roughly as follows: when the heat is transferred from the heat source to the evaporation zone, the liquid phase medium in the cavity will begin to vaporize in the liquid phase in a low vacuum environment, absorb heat energy and expand rapidly in volume, and gradually fill the entire steam cavity. The gas phase medium quickly passes through the steam cavity and is transferred to a colder area, where condensation occurs. The latent heat of phase change is released through the gas-liquid transition. The condensed liquid phase medium will quickly flow back to the evaporation end of the heat source through the capillary phenomenon of the capillary structure on the inner wall of the cavity. This process will be repeated in the cavity.

[0004] The supporting structure of the existing temperature-averaging board is usually a solid metal column, which only provides support between the base plate and the cover plate and has a single function. In recent years, some researchers have proposed an improved supporting structure, which is mainly formed by hot-pressing multiple solid metal columns on the base plate or the cover plate, and then a plurality of tiny (1-2 mm in diameter) metal powder rings are respectively sleeved on each solid metal column, and then sintered. When the temperature-averaging board is working, the porous metal layer formed by sintering the metal powder rings provides reflux power for the condensate, thereby improving the heat dissipation efficiency of the temperature-averaging board. The manufacturing process of this support structure is cumbersome and difficult to implement through an automated process. In addition, it is difficult to form a good metallurgical bond between the metal powder rings and the solid metal columns, base plate and cover plate, and the improvement in the heat dissipation performance of the temperature-averaging board is very limited. Summary of the invention

[0005] The main purpose of the present application is to provide a temperature homogenizing plate and a manufacturing method thereof to overcome the deficiencies of the prior art.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted in this application includes:

[0007] A first aspect of the present application provides a temperature homogenizing plate, comprising:

[0008] The plate body comprises a cover plate and a bottom plate, wherein a closed cavity is formed between the cover plate and the bottom plate, and an inner wall of the closed cavity has an evaporation area and a condensation area;

[0009] Capillary tissue covering the evaporation zone and the condensation zone;

[0010] At least one supporting structure, the supporting structure is arranged in the closed cavity, and two ends of the supporting structure are respectively connected to the cover plate and the bottom plate;

[0011] and, a working fluid, encapsulated in the closed cavity;

[0012] The supporting structure as a whole is a porous structure, and the pore diameter and porosity of the pores contained in the porous structure increase from the inside to the outside along the radial direction.

[0013] In this specification, the evaporation zone is the area where the inner wall of the enclosed cavity is close to the heat source, and the evaporation zone is the area where the inner wall of the enclosed cavity is far from the heat source. For example, if the temperature homogenizing plate is thermally connected to the heat source by its bottom plate, the area where the inner wall of the enclosed cavity is close to the heat source is the evaporation zone, and the area where the inner wall of the enclosed cavity is far from the heat source, that is, the area where the inner wall of the bottom plate is far from the heat source and the inner wall of the upper cover are the condensation zone.

[0014] The support structure with an overall porous structure is adopted in the present application, which can not only provide sufficient support for the inner walls on the opposite sides of the plate body, but also store the working fluid. Moreover, because its core is relatively dense and has low thermal resistance, when the temperature equalizer is working, the core temperature of the support structure is close to the temperature of the VC heat source substrate, which can quickly evaporate the working fluid, that is, it is equivalent to forming a three-dimensional capillary structure in the heat source, which effectively increases the volatilization area of ​​the working fluid in the evaporation zone. At the same time, the support structure is also conducive to the rapid return of the working fluid condensed in the condensation zone to the evaporation zone, thereby effectively improving the heat dissipation performance of the temperature equalizer.

[0015] In one embodiment, the support structure includes a first porous structure, a second porous structure and a third porous structure arranged in sequence from the inside to the outside in the radial direction, and the pore size and porosity of the holes contained in the first porous structure, the second porous structure and the third porous structure increase in sequence. Among them, the structure of the first porous structure is relatively dense, and the thermal resistance with the plate body is low, which is conducive to the rapid conduction of heat from the heat source to the metal structure of the support column. The second porous structure has a large liquid storage capacity and a large contact area with the working fluid, which is conducive to the transfer of heat from the metal structure to the working fluid. The third porous structure has a liquid working fluid adsorbed on the surface of the metal powder, and the gas-liquid two-phase contact area is large, and the liquid working fluid has a greater volatilization rate. Exemplarily, the pore size of the holes contained in the first porous structure, the second porous structure and the third porous structure can be 0.5-10μm, 5-20μm, and 30-100μm, respectively. The porosity of the first porous structure, the second porous structure and the third porous structure may be 10%-40%, 20%-50%, and 50%-70% respectively.

[0016] In one embodiment, the first porous structure, the second porous structure and the third porous structure are all formed by sintering metal powder, and the particle sizes of the metal powders used to form the first porous structure, the second porous structure and the third porous structure are increased in sequence. Exemplarily, the particle sizes of the metal powders used to form the first porous structure, the second porous structure and the third porous structure can be 5-20 μm, 20-50 μm and 50-200 μm respectively.

[0017] In one embodiment, the ratio of the diameter of the first porous structure to the ring diameter (wall thickness) of the second porous structure and the ring diameter (wall thickness) of the third porous structure can be (0.8-2): (0.5-1.5): (0.3-0.8).

[0018] In one embodiment, the supporting structure is entirely a capillary structure.

[0019] In one embodiment, two ends of the support structure are in contact with the evaporation region and the second chamber wall respectively.

[0020] In one embodiment, one end of at least one of the support structures is connected to the capillary structure covering the evaporation region, and the other end is connected to the capillary structure covering the condensation region.

[0021] In the present application, the support structure can be in various shapes, such as a columnar body, a rectangular body, a terrace structure with a regular or irregular radial cross section such as a circular, polygonal, gear-shaped, etc., a wall with a regular or irregular strip radial cross section, etc., and is not limited thereto. In general, the shape of the support structure can be selected according to the needs of the actual application, so that it is conducive to guiding the flow direction of the steam of the working fluid or its condensate, accelerating the evaporation of the working fluid or the reflux of its condensate. In addition, the distribution of the support structure should reduce the resistance of the gas to flow to the condensation zone, and guide the steam gas flow to flow quickly to the condensation zone.

[0022] For example, in one embodiment, a plurality of radial protrusions and / or a plurality of radial depressions are integrally formed on the outer wall of the support structure to further increase the surface area of ​​the support structure. Exemplarily, the support structure is a prism with a gear-shaped radial cross section.

[0023] In one embodiment, the capillary structure includes a first capillary portion and a second capillary portion, the first capillary portion and the second capillary portion cover the evaporation zone and the condensation zone respectively, and the capillary pore size and porosity of the first capillary portion increase in a direction away from the evaporation zone.

[0024] In one embodiment, the first capillary portion includes a first capillary layer, a second capillary layer and a third capillary layer sequentially stacked in a direction away from the evaporation region, and the capillary pore diameters and porosities of the first capillary layer, the second capillary layer and the third capillary layer increase sequentially.

[0025] Exemplarily, the sizes of the holes contained in the first capillary layer, the second capillary layer and the third capillary layer may be 0.5-20 μm, 10-70 μm and 30-100 μm respectively.

[0026] Exemplarily, the porosity of the first capillary layer, the second capillary layer and the third capillary layer may be 10%-40%, 40%-60%, and 50%-70%, respectively.

[0027] Illustratively, the ratio of the thickness of the first capillary layer, the second capillary layer and the third capillary layer may be (0.1-0.5):(1-2):(0.3-1.0).

[0028] In one embodiment, the first capillary layer, the second capillary layer and the third capillary layer are all formed by sintering metal powder, and the particle sizes of the metal powders used to form the first capillary layer, the second capillary layer and the third capillary layer increase in sequence. Exemplarily, the particle sizes of the metal powders used to form the first capillary layer, the second capillary layer and the third capillary layer can be 20-50 μm, 50-100 μm and 100-300 μm respectively.

[0029] Among them, the metal powder used to form the first capillary layer has a small particle size and is connected to the evaporation zone to form a large amount of metallurgical bonding. The thermal resistance with the evaporation zone is small, which is conducive to the rapid transfer of heat to the first capillary layer. The second capillary layer has a large liquid storage capacity and a large contact area with the working fluid, which is conducive to the transfer of heat from the metal structure to the working fluid and has a fast volatilization rate. In the third capillary layer, the liquid working fluid is adsorbed on the surface of the metal powder, and the gas-liquid two-phase contact area is large, which makes the liquid working fluid have a greater volatilization rate.

[0030] Preferably, the particle size of the metal powder used to form the third capillary layer is 150-200 μm. Taking water as the working fluid, in the third capillary layer, due to the large metal particles, water can be adsorbed on the surface of the metal particles to form a non-planar liquid film with a thickness of 10-20 μm, and the volatile area is the sum of the surface areas of the liquid films adsorbed by the surface metal particles.

[0031] In one embodiment, the second capillary portion is connected to the first capillary portion.

[0032] Exemplarily, the first capillary portion covers the evaporation area, and other areas of the inner wall of the temperature vapor chamber are condensation areas and are covered by the second capillary portion.

[0033] The pore sizes and porosities of various regions in the second capillary portion may be the same, substantially the same, gradually change in a direction away from the inner wall of the temperature homogenizing plate, or gradually change in a direction parallel to the inner wall of the temperature homogenizing plate.

[0034] Exemplarily, the capillary pores in the second capillary portion are evenly distributed, and the capillary pore diameter may be 30-100 μm, and the porosity may be 45%-65%.

[0035] The second capillary portion is preferably formed by sintering metal powder, but may also be formed by weaving metal wires or made in other ways.

[0036] In some cases, at least one of the support structures is integrated with the first capillary portion and / or the second capillary portion to further improve the heat dissipation performance of the vapor chamber.

[0037] In the present application, the metal powder used to form the support structure and the capillary structure can be selected from copper powder, silver powder, aluminum powder, copper alloy powder, silver alloy powder, aluminum alloy powder or powder formed by other high thermal conductivity metals, and is not limited thereto. Preferably, the metal powder can be copper powder or copper alloy powder.

[0038] The second aspect of the present application provides a method for manufacturing the temperature homogenizing plate, which comprises:

[0039] A plate body of a temperature homogenizing plate is provided, wherein the plate body comprises a cover plate and a bottom plate, wherein the cover plate can be combined with the bottom plate to form a closed cavity, wherein the inner wall of the closed cavity has an evaporation area and a condensation area;

[0040] Making a capillary structure with a composition for forming a capillary structure, and making the capillary structure cover the evaporation area and the condensation area;

[0041] Using a composition for forming a support structure to make more than one support structure, the support structure as a whole is a porous structure, the pore size and porosity of the holes contained in the porous structure increase radially from the inside to the outside, and the support structure is arranged in the closed cavity, and the two ends of the support structure are respectively connected to the cover plate and the bottom plate;

[0042] And, a working fluid is encapsulated in the closed cavity.

[0043] In one embodiment, the manufacturing method specifically includes:

[0044] Providing a composition for forming a support structure, the composition for forming a support structure comprising a first composition containing a first metal powder, a second composition containing a second metal powder, and a third composition containing a third metal powder, wherein the particle sizes of the first metal powder, the second metal powder, and the third metal powder increase in sequence;

[0045] The first porous structure, the second porous structure and the third porous structure are respectively made of the first composition, the second composition and the third composition, and the first porous structure, the second porous structure and the third porous structure are sequentially arranged from the inside to the outside along the radial direction to form the support structure, and the two ends of at least one of the support structures are respectively arranged on the evaporation area and the condensation area.

[0046] In one embodiment, the manufacturing method specifically includes:

[0047] A composition for forming a capillary structure is provided, wherein the capillary structure comprises a first capillary portion and a second capillary portion, wherein the composition for forming the capillary structure comprises a fourth composition containing a fourth metal powder, a fifth composition containing a fifth metal powder, a sixth composition containing a sixth metal powder, and a seventh composition containing a metal powder, wherein the particle sizes of the fourth metal powder, the fifth metal powder, and the sixth metal powder increase in sequence;

[0048] The first capillary layer, the second capillary layer and the third capillary layer are respectively made of the fourth composition, the fifth composition and the sixth composition, and the first capillary layer, the second capillary layer and the third capillary layer are sequentially stacked in a direction away from the evaporation area to form the first capillary part, and the first capillary part covers the evaporation area;

[0049] The second capillary portion is made of the seventh composition, and the second capillary portion covers the condensation area.

[0050] In the present application, the first to sixth compositions may be mainly composed of metal powder, organic binder, water and / or organic solvent and other dispersants and auxiliary agents that may be added or not. These compositions may be in the form of suspension, slurry and other fluids, so as to facilitate the formation of the support structure, capillary tissue and the like by printing, spraying and the like. In some cases, these compositions may also be in the form of pastes, granules and the like at room temperature or high temperature, and may be formed by various molding methods such as brushing, scraping, injection molding, 3D printing, gel molding, photocuring and the like to form the support structure, capillary tissue and the like.

[0051] Exemplarily, the first composition includes the following components calculated by mass ratio: 60%-90% first metal powder, 20%-30% organic binder, 2%-3% dispersant, 0.4%-0.6% initiator. The second composition includes the following components calculated by mass ratio: 55%-83% second metal powder, 25%-45% organic binder, 2.5%-4.5% dispersant, 0.6%-0.8% initiator. The third composition includes the following components calculated by mass ratio: 48%-70% third metal powder, 30%-55% organic binder, 3.5%-4.5% dispersant, 0.7%-0.85% initiator. The particle sizes of the first metal powder, the second metal powder, and the third metal powder are 5-20μm, 20-50μm, and 50-200μm, respectively.

[0052] Exemplarily, the fourth composition includes the following components calculated by mass ratio: 60%-80% of the fourth metal powder, 25%-40% of the organic binder, 2.5%-4% of the dispersant, and 0.6%-0.8% of the photoinitiator. The fifth composition includes the following components calculated by mass ratio: 55%-75% of the fifth metal powder, 30%-45% of the organic binder, 3.0%-4.5% of the dispersant, and 0.7%-0.85% of the photoinitiator. The sixth composition includes the following components calculated by mass ratio: 45%-70% of the sixth metal powder, 35%-55% of the organic binder, 3.5%-5.5% of the dispersant, and 0.7%-0.85% of the photoinitiator. The particle sizes of the fourth metal powder, the fifth metal powder, and the sixth metal powder are 20-50μm, 50-100μm, and 100-300μm, respectively.

[0053] The organic binder described in the present application can be selected from prepolymers with a molecular weight greater than 100 and less than 10,000, for example, acrylates, epoxy acrylates, polyurethane acrylates, polyester acrylates, etc. The dispersant can be selected from hydroxyethyl acrylate, hydroxypropyl methacrylate, isobornyl acrylate, tripropylene glycol diacrylate, pentaerythritol triacrylate, etc. The initiator can be a thermal initiator or a photoinitiator, for example, it can be selected from benzoin, benzoin butyl ether, 1-hydroxycyclohexyl phenyl ketone, etc. One or more of the first to sixth metal powders can be selected from copper powder, silver powder, aluminum powder, copper alloy powder, silver alloy powder, aluminum alloy powder, or powders formed by other high thermal conductivity metals, and are not limited thereto. Preferably, the metal powder can be selected from copper powder or copper alloy powder.

[0054] In some embodiments, one or more of the first to sixth compositions may be a mixed system having a light-curing or heat-curing property. Furthermore, in some embodiments, these compositions may be used to form the support structure and capillary structure through additive manufacturing processes such as "Rapid Prototyping", "3D Printing", and "Solid Free-form Fabrication".

[0055] In some embodiments, a first composition can be made into a first porous structure body using a first mold, and then the first mold is removed, and a second porous structure body is formed directly on the outer wall of the first porous structure body using a second mold and the second composition, and then the second mold is removed, and a third porous structure body is formed directly on the outer wall of the second porous structure body using a third mold and a third composition, thereby forming a support structure body, and finally the third mold is removed, and the support structure body is sintered to decompose and volatilize the organic binder, and to form a metallurgical bond between the metal powders, thereby obtaining the support structure.

[0056] In some embodiments, the first composition may be firstly made into a green body of a first porous structure using a first mold, then the first mold is removed and sintered to form a first porous structure, and then a second mold and a second composition are directly made into a green body of a second porous structure on the outer wall of the first porous structure, then the second mold is removed and sintered to form a second porous structure, and then a third mold and a third composition are directly made into a green body of a third porous structure on the outer wall of the second porous structure, then the third mold is removed and sintered to form a third porous structure, and finally the support structure is obtained. The sintering is sufficient to decompose and volatilize the organic binder and the like in these compositions, and to form a metallurgical bond between the metal powders therein.

[0057] In some embodiments, the fourth composition can be used to first form a blank for the first capillary layer, and then the fifth composition can be used to directly form a blank for the second capillary layer on the blank for the first capillary layer, and then the sixth composition can be used to directly form a blank for the third capillary structure on the blank for the second capillary layer, thereby forming a blank for the first capillary part. Finally, the blank for the first capillary part is sintered to decompose and volatilize the organic binder and form a metallurgical bond between the metal powders, thereby obtaining the first capillary part.

[0058] In some embodiments, the first capillary portion can be obtained by first using the fourth composition to form a blank for forming a first capillary layer, and then sintering to form the first capillary layer, then using the fifth composition to directly form a blank for forming a second capillary layer on the first capillary layer, and then sintering to form the second capillary layer, and then using the sixth composition to directly form a blank for forming a third capillary structure on the second capillary layer, and then sintering to form the third capillary layer. The sintering is sufficient to decompose and volatilize the organic binder and the like in these compositions, and to form a metallurgical bond between the metal powders therein.

[0059] In some embodiments, the seventh composition may also have a composition that is the same or similar to one or more of the first to sixth compositions, and may also be manufactured in a manner similar to that of the support structure and capillary tissue to form the second capillary portion by printing, spraying, scraping, brushing or additive manufacturing.

[0060] In some more specific embodiments, the bottom plate and / or cover plate of the temperature equalizing plate can be used as a substrate, and the support structure and / or capillary structure blank can be directly manufactured on the substrate, and then the sintering can be performed to simultaneously complete the manufacturing of the support structure and the bonding of the support structure and / or capillary structure with the bottom plate and / or cover plate. This method is simple to operate, and the bonding strength between the support structure and / or capillary structure and the bottom plate and / or cover plate is high, and the thermal resistance is small.

[0061] In other more specific embodiments, the solidified support structure blank and / or capillary structure blank can also be transferred to the bottom plate and / or cover plate of the temperature equalizing plate, and then sintered to complete the production of the support structure and / or capillary structure and the combination of the support structure and / or capillary structure with the bottom plate and / or cover plate. This method can make the production of the support structure and / or capillary structure higher and reduce the restrictions on the shape of the support structure and / or capillary structure caused by the structure of the bottom plate and / or cover plate.

[0062] In other more specific embodiments, the sintered support structure blank and / or capillary structure blank can be transferred to the bottom plate and / or cover plate of the temperature equalizing plate, and then the capillary structure and the substrate can be sintered as described above. However, the bonding strength and thermal resistance between the support structure and / or capillary structure and the bottom plate and / or cover plate may be slightly inferior to those in the aforementioned embodiments.

[0063] In one embodiment, the second capillary portion is connected to the first capillary portion.

[0064] Compared with the prior art, this application has at least the following advantages:

[0065] (1) The supporting structure of the temperature equalizing plate provided in the present application is a porous structure as a whole, and in particular, the pore size and porosity of the porous structure increase from the inside to the outside. It not only has low thermal resistance, but can also serve as a three-dimensional evaporation structure to coordinate the capillary structure of the evaporation zone to significantly improve the evaporation efficiency of the working fluid, and can also form a flow channel to greatly increase the reflux speed of the condensed working fluid, thereby effectively improving the heat dissipation performance of the temperature equalizing plate.

[0066] (2) Preferably, the capillary structure covering the evaporation zone in the temperature equalizer provided by the present application has an aperture and porosity that increases in sequence in the direction away from the evaporation zone, which can reduce the thermal resistance between the capillary structure and the temperature equalizer body on the one hand, and greatly increase the contact area between the capillary structure and the working fluid on the other hand, thereby significantly increasing the evaporation rate of the working fluid in the evaporation zone and further improving the heat dissipation performance of the temperature equalizer. In addition, by arranging a porous structure with a certain height on the evaporation zone and a certain distance from the upper cover plate, the volatilization area of ​​the evaporation zone can be further increased.

[0067] (3) The supporting structure and capillary structure in the temperature equalizing plate provided in the present application can be manufactured by an additive manufacturing method based on photocuring / thermal curing reaction. The process is simple and highly controllable. It can achieve fine control of the structure of the supporting structure and the capillary structure with high yield, and is suitable for large-scale production of products such as temperature equalizing plates.

[0068] (4) The shape and distribution of the supporting structure in the temperature equalizing plate provided in the present application can be freely designed, which is conducive to the flow of high-temperature steam to the condensation area. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 is a schematic cross-sectional structure diagram of a temperature homogenizing plate in a typical embodiment of the present application;

[0070] Figure 2 is a schematic diagram of a radial cross-sectional structure of a support structure in a typical embodiment of the present application;

[0071] Figure 3 is a schematic diagram of an axial cross-sectional structure of a support structure in a typical embodiment of the present application;

[0072] Figure 4 is a schematic diagram of the cross-sectional structure of a first capillary portion in a typical embodiment of the present application;

[0073] Figure 5 This is a physical photo of a product 1 in Example 1 of the present application. DETAILED DESCRIPTION

[0074] The technical solution of the present application will be explained in more detail below with reference to the accompanying drawings and embodiments.

[0075] Example 1 Please refer to Figure 1-Figure 4 As shown, a typical embodiment of the present application provides a temperature homogenizing plate comprising:

[0076] A plate body 1, which is formed by combining a cover plate 11 and a bottom plate 12, wherein the cover plate 11 and the bottom plate 12 enclose a closed chamber, wherein the inner wall of the cover plate has a first surface 110, and the inner wall of the bottom plate has a second surface 120, the first surface and the second surface are arranged opposite to each other, and a local area of ​​the first surface is close to a heat source, so it can be defined as an evaporation area or a heat source area, and the area of ​​the inner wall of the bottom plate far from the heat source and the inner wall of the cover plate together constitute a condensation area;

[0077] The capillary structure 2 is distributed in the closed chamber and includes a first capillary portion 21 and a second capillary portion 22, wherein the first capillary portion 21 covers the evaporation area, and the second capillary portion 22 covers the condensation area;

[0078] A plurality of support columns 3 are arranged at intervals from each other, one end of each support column 3 is combined with the capillary structure covered on the first surface 110, and the other end is combined with the capillary structure covered on the second surface 120, wherein one end of some support columns 3 is combined with the first capillary portion 21;

[0079] And, the working fluid (not shown in the figure) is encapsulated in the closed cavity.

[0080] The support column 3 includes a first porous structure 31, a second porous structure 32 and a third porous structure 33 which are arranged radially from the inside to the outside. The first porous structure 31, the second porous structure 32 and the third porous structure 33 are integrated, and the pore diameters of the holes contained therein are 0.5-10 μm, 5-20 μm, 30-100 μm, and the porosity is 10%-40%, 20%-50%, and 50%-70%. The diameter of the first porous structure 31, the ring diameter (wall thickness) of the second porous structure 32, and the wall thickness of the third porous structure 33 are 1 mm, 1 mm, and 0.5 mm, respectively.

[0081] Among them, the first capillary part 21 includes a first capillary layer 211, a second capillary layer 212 and a third capillary layer 213 which are stacked in sequence along a direction away from the evaporation zone. The first capillary layer 211, the second capillary layer 212 and the third capillary layer 213 are integrated into one body, and the pore sizes of the pores contained therein are 0.5-20μm, 10-70μm, 30-100μm, respectively, the porosity is 10%-40%, 40%-60%, 50%-70%, respectively, and the thickness is 0.1mm, 0.5mm, 0.4mm, respectively.

[0082] The capillary pores in the second capillary portion 22 are evenly distributed, with a pore diameter of 30-100 μm and a porosity of 50%-70%.

[0083] In this embodiment, the support column 3, the first capillary portion 21 and the second capillary portion 22 are formed by sintering metal powders of different particle sizes, and the metal powders are preferably copper powders or copper alloy powders, etc. Preferably, at least part of the support column 3 is integrated with the first capillary portion 21 and / or the second capillary portion 22.

[0084] In this embodiment, the bottom plate and the cover plate can be made of metals with high thermal conductivity such as copper or its alloy, aluminum or its alloy, etc. The working fluid can be liquids with good volatility such as water and alcohol.

[0085] For example, in this embodiment, the bottom plate and cover plate of a temperature-averaging plate product (defined as product 1) are both made of a copper plate with a thickness of 1 mm, and the size of its inner cavity (i.e., the aforementioned closed cavity) is 80 mm×120 mm×4 mm. The 25 mm×25 mm area at the center of the inner wall of the bottom plate is the evaporation zone. The thicknesses of the first capillary layer, the second capillary layer, and the third capillary layer in the first capillary part combined with the evaporation zone are 0.1 mm: 0.5 mm: 0.4 mm, respectively. The pore sizes of the holes contained in the first capillary layer, the second capillary layer, and the third capillary layer are 0.5-20 μm, 10-70 μm, and 30-100 μm, respectively, and the porosity is 10%-40%, 40%-60%, and 50%-70%, respectively. The second capillary part covers all the areas on the inner wall of the temperature-averaging plate except the evaporation zone, and is combined with the first capillary part. The thickness of the second capillary part is 1mm, the average pore size of the holes contained therein is 30-100μm, and the porosity is 50%-70%. At the same time, a plurality of cylindrical support columns are evenly distributed in the inner cavity, and the upper and lower ends of each support column are respectively combined with the bottom plate and the cover plate. The diameter of the first porous structure of each support column, the ring diameter of the second porous structure, and the wall thickness of the ring of the third porous structure are 1mm, 1mm, and 0.5mm, respectively. The pore sizes of the holes contained in the first porous structure, the second porous structure, and the third porous structure are 0.5-20μm, 10-70μm, and 30-100μm, respectively, and the porosity is 10%-40%, 40%-60%, and 50%-70%, respectively. The first capillary part, the second capillary part, and the support column are all formed by sintering copper powder. The actual photo of the product is shown in Figure 5 shown.

[0086] Embodiment 2 This embodiment also provides a method for preparing the product 1, which comprises the following steps:

[0087] S1. Provide compositions for making support columns and capillary structures, respectively, including:

[0088] The first composition includes 76 wt % copper powder (average particle size is 10 μm), 21 wt % organic binder, 0.5 wt % photoinitiator, and 2.5 wt % dispersant.

[0089] The second composition includes 69.6 wt % copper powder (average particle size is 40 μm), 27 wt % organic binder, 0.7 wt % photoinitiator, and 2.7 wt % dispersant.

[0090] The third composition includes 60.75 wt % copper powder (with an average particle size of 100 μm), 35 wt % organic binder, 0.75 wt % photoinitiator, and 3.5 wt % dispersant.

[0091] The fourth composition includes 68.5 wt % copper powder (average particle size is 40 μm), 28 wt % organic binder, 0.7 wt % photoinitiator, and 2.8 wt % dispersant.

[0092] The fifth composition includes 64 wt % copper powder (with an average particle size of 80 μm), 32 wt % organic binder, 0.8 wt % photoinitiator, and 3.2 wt % dispersant.

[0093] The sixth composition includes 58.7 wt % copper powder (with an average particle size of 100 μm), 37 wt % organic binder, 0.8 wt % photoinitiator, and 3.5 wt % dispersant.

[0094] The seventh composition includes 57.6 wt % copper powder (with an average particle size of 120 μm), 38 wt % organic binder, 0.8 wt % photoinitiator, and 3.6 wt % dispersant.

[0095] The organic binders are all polyester acrylates purchased from Hubei Xinmingtai Chemical Co., Ltd. The photoinitiators are all benzoin butyl ether and the dispersants are all hydroxyethyl acrylate.

[0096] S2. Apply the fourth composition on the evaporation area of ​​the inner wall of the bottom plate and irradiate with ultraviolet light to form a blank of the first capillary layer; then apply the fifth composition on the blank of the first capillary layer and irradiate with ultraviolet light to form a blank of the second capillary layer; then apply the sixth composition on the blank of the second capillary layer and irradiate with ultraviolet light to form a blank of the third capillary layer, thereby obtaining a blank of the first capillary part.

[0097] And, the seventh composition is coated on the other areas of the inner wall of the temperature homogenizing plate except the evaporation area, namely the condensation area, and irradiated with ultraviolet light, so as to obtain a blank of the second capillary part.

[0098] S3, placing a first mold having a plurality of first vertical through holes on the blank of the capillary structure covering the first surface 110 of the inner wall of the bottom plate, and filling each first vertical through hole with a first composition, and then irradiating with ultraviolet light to cure the first composition in each first vertical through hole to form a blank of a first porous structure, and then removing the first mold;

[0099] A second mold having a plurality of second vertical through holes is arranged on the blank of the capillary structure covering the first surface 110 of the inner wall of the bottom plate, and each blank of the first porous structure is coaxially arranged in a corresponding second vertical through hole, and then a second composition is filled in a first annular space formed between the outer wall of each blank of the first porous structure and the inner wall of the second vertical through hole, and then irradiated with ultraviolet light to cure the second composition in each annular space to form a blank of the second porous structure, and then the second mold is removed;

[0100] A third mold having a plurality of third vertical through holes is disposed on a blank of a capillary structure covering the first surface 110 of the inner wall of the bottom plate, and each blank of the second porous structure is coaxially disposed in a corresponding third vertical through hole, and then a third composition is filled in a second annular space formed between the outer wall of each blank of the second porous structure and the inner wall of the second vertical through hole, and then irradiated with ultraviolet light to solidify the third composition in each annular space to form a blank of a third porous structure, and then the third mold is removed, thereby forming a blank of a plurality of support columns on the bottom plate.

[0101] Of course, the support column blank can also be made on the capillary structure blank covering the second surface 120 of the inner wall of the cover plate in the same manner, or part of the support columns can be made on the capillary structure blank covering the first surface 110 of the inner wall of the base plate, and the remaining support columns can be made on the capillary structure blank covering the second surface 120 of the inner wall of the cover plate.

[0102] S4. After completing steps S1-S3, the base plate and cover plate carrying the support column and the capillary structure are sintered at about 950°C for about 60 minutes under vacuum conditions. Then, the base plate and the cover plate are sealed and combined, and the inner cavity of the temperature-averaging plate is evacuated, and then water is injected, and the water injection amount is 120% of the water volume of the capillary layer in the temperature-averaging plate.

[0103] Embodiment 3 This embodiment also provides a method for preparing the product 1, which comprises the following steps:

[0104] S1. Same as Example 2.

[0105] S2, covering a first mold having a plurality of first vertical through holes on a ceramic substrate, and filling each first vertical through hole with a first composition, and then irradiating with ultraviolet light to solidify the first composition in each first vertical through hole to form a green body with a first porous structure, and then removing the first mold;

[0106] Covering a second mold having a plurality of second vertical through holes on the ceramic substrate, and coaxially arranging each green body of the first porous structure in a corresponding second vertical through hole, and then filling a second composition in a first annular space formed between an outer wall of each green body of the first porous structure and an inner wall of the second vertical through hole, and then irradiating with ultraviolet light to cure the second composition in each annular space to form a green body of the second porous structure, and then removing the second mold;

[0107] A third mold having a plurality of third vertical through holes is covered on the ceramic substrate, and each second porous structure blank is coaxially arranged in a corresponding third vertical through hole, and then a third composition is filled in the second annular space formed between the outer wall of each second porous structure blank and the inner wall of the second vertical through hole, and then irradiated with ultraviolet light to solidify the third composition in each annular space to form a third porous structure blank, and then the third mold is removed to form a plurality of support column blanks on the ceramic substrate, and then sintered at a high temperature of about 950°C for about 60 minutes under vacuum conditions to form a plurality of support columns.

[0108] S3, coating the fourth composition, the fifth composition, and the sixth composition on a ceramic substrate in sequence, and irradiating with ultraviolet light to form a blank of the first capillary part, and then sintering at a high temperature of about 950° C. for about 20 minutes under vacuum conditions to form the first capillary part. And, coating the seventh composition on a ceramic substrate, and irradiating with ultraviolet light to form a blank of the second capillary part, and then sintering at a high temperature of about 980° C. for about 120 minutes under vacuum conditions to form the second capillary part.

[0109] S4. After completing steps S1-S3, fix each support column and capillary structure on the bottom plate and the cover plate, then seal the cover plate and the bottom plate, and sinter at a high temperature of about 920°C for about 30 minutes under vacuum conditions. Then, evacuate the inner cavity of the temperature equalizing plate and inject water. The water injection amount is 120% of the water volume of the capillary layer in the temperature equalizing plate.

[0110] Comparative Example 1: The structure of a temperature equalizing plate product (defined as Product 2) in this comparative example is basically the same as that of Product 1, with the difference that the first porous structure, the second porous structure and the third porous structure in each support column are replaced by solid copper columns with the same diameter.

[0111] Comparative Example 2: The structure of a temperature equalizing plate product (defined as Product 3) in this comparative example is basically the same as that of Product 1, with the difference that each support column is replaced by a capillary column of the same diameter, the pores in the capillary column are evenly distributed, and the average pore size and porosity are the same as those of the first porous structure.

[0112] Comparative Example 3: The structure of a temperature equalizing plate product (defined as Product 4) in this comparative example is basically the same as that of Product 1, with the difference that each support column is replaced by a capillary column of the same diameter, the pores in the capillary column are evenly distributed, and the average pore size and porosity are the same as those of the second porous structure.

[0113] Comparative Example 4: The structure of a temperature equalizing plate product (defined as Product 5) in this comparative example is basically the same as that of Product 1, with the difference that each support column is replaced by a capillary column of the same diameter, the pores in the capillary column are evenly distributed, and the average pore size and porosity are the same as those of the third porous structure.

[0114] Comparative Example 5: The structure of a temperature distribution plate product (defined as Product 6) in this comparative example is basically the same as that of Product 1, except that the second porous structure in each support column is omitted.

[0115] Comparative Example 6: The structure of a temperature equalizing plate product (defined as Product 7) in this comparative example is basically the same as that of Product 1, with the difference that each first capillary portion is replaced by a capillary core of the same thickness, the holes in the capillary core are evenly distributed, and the average pore size and porosity are the same as those of the first capillary layer.

[0116] Comparative Example 7: The structure of a temperature equalizing plate product (defined as Product 8) in this comparative example is basically the same as that of Product 1, with the difference that each first capillary portion is replaced by a capillary core of the same thickness, the holes in the capillary core are evenly distributed, and the average pore size and porosity are the same as those of the second capillary layer.

[0117] Comparative Example 8: The structure of a temperature equalizing plate product (defined as Product 9) in this comparative example is basically the same as that of Product 1, with the difference that each first capillary portion is replaced by a capillary core of the same thickness, the holes in the capillary core are evenly distributed, and the average pore size and porosity are the same as those of the third capillary layer.

[0118] Comparative Example 9: The structure of a temperature distribution board product (defined as product 10) in this comparative example is basically the same as that of product 1, except that the second capillary layer in each first capillary portion is omitted.

[0119] The power of product 1 to product 10 is 500W, and there is flowing water cooling in the cooling section. The heat source temperature and thermal resistance of the tested VC are shown in Table 1 below.

[0120] Table 1 Thermal resistance test results of products 1-10

[0121]

[0122] In addition, the applicant also referred to Examples 1 to 3 and prepared temperature vapor chamber products of various specifications using other raw materials and conditions listed in the specification of this application, and tested the thermal resistance and other properties of these products. The results showed that these products also exhibited excellent heat dissipation performance.

[0123] It should be understood that the technical solution of the present application is not limited to the above-mentioned specific implementation cases. Any technical deformation made according to the technical solution of the present application without departing from the purpose of the present application and the scope of protection of the claims shall fall within the scope of protection of the present application.

Claims

1. A temperature homogenizing plate, comprising: The plate body comprises a cover plate and a bottom plate, wherein a closed cavity is formed between the cover plate and the bottom plate, and an inner wall of the closed cavity has an evaporation area and a condensation area; Capillary tissue covering the evaporation zone and the condensation zone; At least one supporting structure, the supporting structure is arranged in the closed cavity, and two ends of the supporting structure are respectively connected to the cover plate and the bottom plate; and, a working fluid, encapsulated in the closed cavity; The feature of the invention is that the supporting structure as a whole is a porous structure, and the pore diameter and porosity of the pores contained in the porous structure increase from the inside to the outside along the radial direction.

2. The temperature homogenizing plate according to claim 1, characterized in that: The support structure includes a first porous structure, a second porous structure and a third porous structure which are arranged in sequence from the inside to the outside along the radial direction, and the pore diameters and porosities of the pores contained in the first porous structure, the second porous structure and the third porous structure increase in sequence.

3. The temperature equalizing plate according to claim 2, characterized in that: The first porous structure, the second porous structure and the third porous structure are all formed by sintering metal powder, and the particle sizes of the metal powder used to form the first porous structure, the second porous structure and the third porous structure increase in sequence.

4. The temperature equalizing plate according to any one of claims 1 to 3, characterized in that: The supporting structure as a whole is a capillary structure; and / or, one end of at least one of the supporting structures is connected to the capillary structure covering the evaporation area, and the other end is connected to the capillary structure covering the condensation area; And / or, a plurality of radial protrusions and / or a plurality of radial recesses are integrally formed on the outer wall of the support structure.

5. The temperature homogenizing plate according to claim 1, characterized in that: The capillary structure includes a first capillary portion and a second capillary portion, wherein the first capillary portion and the second capillary portion cover the evaporation region and the condensation region respectively, and the capillary pore diameter and porosity of the first capillary portion increase in a direction away from the evaporation region.

6. The temperature homogenizing plate according to claim 5, characterized in that: The first capillary portion includes a first capillary layer, a second capillary layer and a third capillary layer which are sequentially stacked in a direction away from the evaporation region, and the capillary pore diameters and porosities of the first capillary layer, the second capillary layer and the third capillary layer increase sequentially.

7. The temperature homogenizing plate according to claim 6, characterized in that: The first capillary layer, the second capillary layer and the third capillary layer are all formed by sintering metal powder, and the particle sizes of the metal powder used to form the first capillary layer, the second capillary layer and the third capillary layer increase in sequence.

8. The temperature homogenizing plate according to claim 5, characterized in that: The second capillary portion is connected to the first capillary portion.

9. A method for manufacturing a temperature equalizing plate, characterized in that: include: A plate body of a temperature homogenizing plate is provided, wherein the plate body comprises a cover plate and a bottom plate, wherein the cover plate can be combined with the bottom plate to form a closed cavity, wherein the inner wall of the closed cavity has an evaporation area and a condensation area; Making a capillary structure with a composition for forming a capillary structure, and making the capillary structure cover the evaporation area and the condensation area; Using a composition for forming a support structure to make more than one support structure, the support structure as a whole is a porous structure, the pore size and porosity of the holes contained in the porous structure increase radially from the inside to the outside, and the support structure is arranged in the closed cavity, and the two ends of the support structure are respectively connected to the cover plate and the bottom plate; And, a working fluid is encapsulated in the closed cavity.

10. The manufacturing method according to claim 9, characterized in that: Specifically include: Providing a composition for forming a support structure, the composition for forming a support structure comprising a first composition containing a first metal powder, a second composition containing a second metal powder, and a third composition containing a third metal powder, wherein the particle sizes of the first metal powder, the second metal powder, and the third metal powder increase in sequence; The first porous structure, the second porous structure and the third porous structure are respectively made of the first composition, the second composition and the third composition, and the first porous structure, the second porous structure and the third porous structure are sequentially arranged from the inside to the outside along the radial direction to form the support structure, and the two ends of at least one of the support structures are respectively arranged on the evaporation area and the condensation area.

11. The manufacturing method according to claim 9, characterized in that: Specifically include: A composition for forming a capillary structure is provided, wherein the capillary structure comprises a first capillary portion and a second capillary portion, wherein the composition for forming the capillary structure comprises a fourth composition containing a fourth metal powder, a fifth composition containing a fifth metal powder, a sixth composition containing a sixth metal powder, and a seventh composition containing a metal powder, wherein the particle sizes of the fourth metal powder, the fifth metal powder, and the sixth metal powder increase in sequence; The first capillary layer, the second capillary layer and the third capillary layer are respectively made of the fourth composition, the fifth composition and the sixth composition, and the first capillary layer, the second capillary layer and the third capillary layer are sequentially stacked in a direction away from the evaporation area to form the first capillary part, and the first capillary part covers the evaporation area; The second capillary portion is made of the seventh composition, and the second capillary portion covers the condensation area.

12. The manufacturing method according to claim 11, characterized in that: The second capillary portion is connected to the first capillary portion.

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