CN113498295A

CN113498295A - Ultrathin soaking plate, preparation method thereof and electronic equipment

Info

Publication number: CN113498295A
Application number: CN202010195591.8A
Authority: CN
Inventors: 汤勇; 聂聪; 刘用鹿; 靳林芳; 陈恭; 范东强; 段龙华; 王英先
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2021-10-12
Anticipated expiration: 2040-03-19
Also published as: CN113498295B

Abstract

The invention relates to an ultrathin vapor chamber, a preparation method thereof and electronic equipment, wherein the vapor chamber comprises a first cover plate and a second cover plate; the first cover plate and the second cover plate are connected in a sealing mode to form a sealed cavity, a negative pressure environment is arranged in the sealed cavity, a capillary structure and a cooling medium are arranged in the sealed cavity, and the inner surface of the first cover plate and/or the inner surface of the second cover plate and/or the capillary structure comprise a hydrophobic structure layer and a hydrophilic structure layer; the hydrophobic structure layer is obtained by performing surface hydrophobic treatment on the first cover plate and/or the second cover plate and/or the capillary structure after etching or deposition or film layer treatment. The ultra-thin vapor chamber that this application embodiment provided utilizes the formation that hydrophobic structural layer can effectual prevention liquid film, has improved gasification core density, reduces the wall superheat degree, makes ultra-thin vapor chamber's radial thermal resistance reduce simultaneously, has promoted ultra-thin vapor chamber's samming performance and heat transfer performance.

Description

Ultrathin soaking plate, preparation method thereof and electronic equipment

Technical Field

The application relates to the technical field of mobile terminals, in particular to an ultrathin soaking plate, a preparation method of the ultrathin soaking plate and electronic equipment.

Background

The design of the soaking plate utilizes the principle that the cooling liquid absorbs or releases latent heat of phase change when the phase of the cooling liquid changes. When heat is conducted to the soaking plate from the heat source, the packaged cooling liquid in the cavity starts to generate gasification phenomenon after being heated in the environment with low vacuum degree, absorbs heat and flows to the cold end, condenses and releases heat after encountering cold, and then returns to the heat source end through the capillary action of the capillary structure on the inner wall of the cavity, so that the soaking effect is achieved.

At present, vapor chamber has been widely used in terminal electronic products such as mobile phones, tablets and notebook computers, the terminal electronic products are light, thin and portable, and are limited by size and weight, the vapor chamber is also developed towards light, thin, large-area and large-span direction, but the capillary structure of the ultra-thin vapor chamber is mainly a wire mesh structure and a groove structure, due to the hydrophilicity of the capillary structure, a layer of liquid film is easily formed on the surface of the capillary structure by cooling liquid, so that the rate of generating and dropping internal bubbles of the cooling liquid during heat exchange is slowed down, the radial thermal resistance of the ultra-thin vapor chamber is increased, the superheat degree of the heat exchange wall surface is increased, and the uniform temperature performance and the heat transfer performance of the ultra-thin vapor chamber are deteriorated.

Disclosure of Invention

In order to overcome the problems in the prior art, the application provides the ultrathin soaking plate, the preparation method thereof and the electronic equipment, which can prevent a liquid film from being formed and improve the heat uniformity and the heat conductivity of the ultrathin soaking plate.

In a first aspect, the present application provides an ultra-thin vapor chamber comprising a first cover plate and a second cover plate; the first cover plate and the second cover plate are connected in a sealing mode to form a sealed cavity, a negative pressure environment is arranged in the sealed cavity, a capillary structure and a cooling medium are arranged in the sealed cavity, and a hydrophobic structure layer and a hydrophilic structure layer are arranged on the inner surface of the first cover plate and/or the inner surface of the second cover plate and/or the capillary structure; the hydrophobic structure layer is obtained by performing surface hydrophobic treatment on the first cover plate and/or the second cover plate and/or the capillary structure after etching or deposition or film layer treatment.

With reference to the first aspect, in a possible implementation manner, the first cover plate and the second cover plate are made of any one of pure copper, a copper alloy, stainless steel, an aluminum alloy, a titanium metal, a titanium alloy, or a plastic.

In combination with the first aspect, in a possible embodiment, the thickness of the hydrophobic structure layer is 0.001 to 0.2 mm.

With reference to the first aspect, in a possible implementation manner, the hydrophilic structure layer is obtained by sintering a porous medium made of a metal material, and the thickness of the hydrophilic structure layer is 0.03 to 0.2 mm.

With reference to the first aspect, in a possible implementation manner, the first cover plate and the second cover plate are diffusion welded, brazed or laser welded, and the thickness of the welded soaking plate is 0.1-0.4 mm.

With reference to the first aspect, in a possible implementation manner, the hydrophobic structural layer is disposed on an inner surface of the first cover plate, and the hydrophilic structural layer is disposed on an inner surface of the second cover plate.

With reference to the first aspect, in a possible embodiment, the hydrophobic structure layer and the hydrophilic structure layer are spliced or stacked on an inner surface of the first cover plate and/or the second cover plate.

With reference to the first aspect, in a possible embodiment, the capillary structure includes the hydrophobic structure layer and the hydrophilic structure layer arranged in a stacked or spliced manner.

In a possible embodiment in combination with the first aspect, the cooling medium is deionized water or ultrapure water.

With reference to the first aspect, in a possible implementation manner, the vapor chamber further includes a supporting structure, the supporting structure is disposed in the sealed cavity of the shell and used for maintaining the shape of the shell, and the supporting structure abuts between the first cover plate and the second cover plate.

In a second aspect, the present application provides a method for preparing an ultra-thin vapor chamber, the method comprising:

cleaning and drying the first cover plate and the second cover plate, and then carrying out etching or deposition or film surface treatment; wherein the etching treatment comprises any one of laser etching or chemical etching, and the film layer treatment comprises any one of electroplating, chemical acid washing and chemical alkali washing;

soaking the inner surface of the first cover plate and/or the second cover plate in a stearic acid solution, and self-assembling for 8-10 hours at 25-40 ℃ to obtain a hydrophobic structure layer;

sintering a metal porous medium at a high temperature of 800-980 ℃ for 3-4 hours to form a hydrophilic structure layer on the inner surface of the first cover plate and/or the second cover plate;

buckling the first cover plate and the second cover plate to form a cavity with an opening, and welding in a protective atmosphere;

and injecting a cooling medium into the cavity through the opening, extracting air in the cavity through the opening to enable the cavity to be in a negative pressure state, plugging the opening, and welding and sealing to manufacture the ultrathin soaking plate.

With reference to the second aspect, in a possible implementation manner, the material of the first cover plate and the second cover plate is any one of pure copper, a copper alloy, stainless steel, an aluminum alloy, a titanium metal, a titanium alloy, or a plastic.

With reference to the second aspect, in one possible embodiment, the first cover plate and the second cover plate are cleaned and dried and then subjected to an etching process, which includes:

immersing the first cover plate and the second cover plate in an absolute ethyl alcohol solution, carrying out ultrasonic cleaning, removing oil stains on the surface of the cover plate, and drying;

then, arranging the dried first cover plate and the dried second cover plate in an etching solution for etching for 35-40 minutes, wherein the etching solution comprises a ferric sulfate solution and a sulfuric acid solution;

and cleaning the etched first cover plate and the etched second cover plate by using deionized water and then drying.

In combination with the second aspect, in a possible embodiment, the stearic acid solution is 0.1 to 0.25 mol/L.

In combination with the second aspect, in a possible embodiment, the thickness of the soaking plate is 0.1 to 0.4 mm.

In combination with the second aspect, in a possible embodiment, the thickness of the hydrophobic structure layer is 0.001 to 0.2 mm.

In combination with the second aspect, in a possible embodiment, the porous medium is a copper wire mesh, the pore size of the wire mesh is 200 to 450 meshes, and the thickness of the hydrophilic structural layer is 0.03 to 0.2 mm.

In a possible embodiment in combination with the second aspect, the cooling medium is deionized water or ultrapure water.

In combination with the second aspect, in one possible embodiment, the protective atmosphere is a mixed gas of hydrogen and nitrogen.

In a third aspect, the present application provides an electronic device, including a working module and a heat dissipation module, the heat dissipation module includes the above-mentioned ultra-thin vapor chamber, the ultra-thin vapor chamber is used for right the heat dissipation of the working module.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

FIG. 1 is a schematic structural view of a vapor chamber provided in the prior art;

fig. 2 is a schematic view of a heat dissipation mechanism of the ultra-thin soaking plate according to the embodiment of the present application;

fig. 3 is a schematic structural view of an ultra-thin vapor chamber provided in an embodiment of the present application;

fig. 4 is a schematic structural view of an ultra-thin vapor chamber according to an embodiment of the present invention;

fig. 5a is a top view of an ultra-thin soaking plate according to an embodiment of the present application;

FIG. 5b is a top view of another ultra-thin vapor chamber provided in an embodiment of the present application;

FIG. 5c is a top view of another ultra-thin vapor chamber provided in accordance with an embodiment of the present application;

FIG. 6 is a schematic structural view of another ultra-thin vapor chamber provided in the embodiments of the present application;

FIG. 7 is a schematic structural view of another ultra-thin vapor chamber provided in the embodiments of the present application;

FIG. 8 is a schematic structural view of another ultra-thin vapor chamber provided in the embodiments of the present application;

FIG. 9 is a schematic structural view of another ultra-thin vapor chamber provided in the embodiments of the present application;

FIG. 10 is a schematic structural view of another ultra-thin vapor chamber provided in the embodiments of the present application;

FIG. 11 is a schematic structural view of another ultra-thin vapor chamber provided in the embodiments of the present application;

fig. 12 is a schematic structural view of a concave graphite mold according to an embodiment of the present disclosure;

fig. 13 is a schematic structural diagram of a convex graphite mold according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In the description of the present application, unless explicitly stated or limited otherwise, the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; unless specified or indicated otherwise, the term "at least one" means one or more, and the term "plurality" means two or more; the terms "connected," "fixed," and the like are to be construed broadly and may, for example, be fixedly connected, detachably connected, integrally connected, or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In the present application, "and/or" describes an association relationship of associated objects, which means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated 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 the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

For ease of understanding, examples are given in part to illustrate concepts related to embodiments of the present application.

The soaking plate can be also called as a soaking plate, a super heat conducting plate or a heat conducting plate. Vapor Chamber (VC) is similar to Heat pipe (Heat pipe) principle, and the liquid phase boiling phase change of working medium (cooling medium) in the sealed cavity is changed into gas phase Heat absorption, and the gas phase is condensed into liquid phase Heat release, and capillary force, gravity and the like are used as liquid phase working medium to transport power, so that the phase change circulation of the gas phase and the liquid phase in the VC cold and hot areas is completed, and thus, high-efficiency Heat exchange is realized by means of phase change latent Heat, Heat conduction, convection and the like. The vapor chamber can be regarded as a heat pipe with higher shape freedom, irregular design and large-span can be realized, namely the heat pipe is applied to one-dimensional heat dissipation, and the vapor chamber can also realize two-dimensional and three-dimensional heat dissipation.

The soaking plate provided by the technical scheme is applied to electronic equipment, such as mobile phones, tablet computers and notebook computers, and related modules, structural parts, functional parts and the like with heat dissipation functions. The electronic apparatus includes a work module and a heat dissipation module, the heat dissipation module includes a vapor chamber 100, and the vapor chamber 100 is used to dissipate heat from the work module. The temperature equalizing performance and the heat transfer performance of the electronic equipment with the soaking plate 100 are obviously improved.

Fig. 1 is a schematic structural diagram of a vapor chamber in the prior art, and as shown in fig. 1, a vapor chamber 100 'is composed of an upper cover plate 10', a lower cover plate 20 ', a capillary structure 30', a working medium (not shown), and the like. Specifically, the upper cover plate 10 'and the lower cover plate 20' of the soaking plate can be welded and sealed to form a sealed cavity 40 ', the capillary structure layer 30' can be arranged inside the sealed cavity 40 ', and a certain amount of cooling medium (for example, water) is filled in the capillary structure layer 30', so as to form a phase change circulation system. The heat dissipation process of the soaking plate is also a two-phase heat dissipation process which utilizes the cooling medium to generate gas-liquid two-phase change.

For better understanding of the technical solution, the working principle of the embodiment is first described here, and fig. 2 is a schematic view of the working principle of the soaking plate provided in the embodiment of the present application, as shown in fig. 2, the soaking plate 100 includes an evaporation zone and a cooling zone, two zones are determined according to specific working scene needs, and may be the whole upper cover plate or the whole lower cover plate, or may be a certain part of the upper cover plate or the whole lower cover plate. When heat is conducted from the heat source to the evaporation zone of the soaking plate 100, the cooling medium in the sealed cavity starts to generate a gasification phenomenon after being heated in the environment with low vacuum degree, at the moment, the volume of absorbed heat energy rapidly expands, the whole sealed cavity is rapidly filled with the gaseous cooling medium, and the phenomenon of condensation is generated when the gaseous cooling medium enters the cooling zone. The heat accumulated during evaporation is released by the condensation phenomenon, and the condensed cooling medium returns to the evaporation heat source by the capillary structure, and the operation is performed in the sealed cavity repeatedly.

Therefore, the heat dissipation function of the vapor chamber is mainly achieved by the gas-liquid two-phase change of the cooling medium. The heat dissipation process of the soaking plate comprises four main steps of conduction, evaporation, convection and condensation. The vaporization inside the soaking plate continues, and the internal pressure thereof is kept in equilibrium along with the change of the temperature. The soaking plate has large size coverage range and flexible layout, and the size specification of the soaking plate can be designed according to the actual size and the distribution condition of the heat source, so that the heat source can be flexibly covered, and the heat dissipation of a plurality of heat sources can be realized simultaneously.

As can be seen from the above working principle, the vapor chamber 100 in the embodiment provides a sealed space for the cooling medium to perform gas-liquid two-phase conversion therein. Water is generally selected as the cooling medium, considering that different cooling media have different potential phase change capacities when gas-liquid two-phase transformation occurs.

The existing vapor chamber has the advantages that due to the hydrophilicity of the capillary structure, a layer of liquid film is formed on the surface of the capillary structure by a cooling medium, so that the speed of generating and falling off internal bubbles of the cooling medium in heat exchange is reduced, the radial thermal resistance of the vapor chamber is increased, the superheat degree of the heat exchange wall surface is increased, and the uniform temperature performance and the heat transfer performance of the vapor chamber are poor.

In view of the problems in the prior art, the following discussion continues to discuss the technical solutions of the embodiments of the present invention.

The embodiment of the application provides an ultrathin soaking plate. It should be noted that the actual vapor chamber can be designed irregularly with different thicknesses according to the product, and is not limited to a cuboid. Fig. 3 shows a schematic view of the overall structure of an ultrathin soaking plate provided by the embodiment of the application. As shown in fig. 3, the vapor chamber 100 includes a first cover plate 10, a second cover plate 20, and a capillary structure 30, wherein the first cover plate 10 and the second cover plate 20 are hermetically connected to form a housing having a sealed cavity 40. The interior of the sealed cavity 40 is a negative pressure environment and is provided with a cooling medium. Further, through the opening provided on the housing, it is possible to evacuate the inside of the sealed chamber 40 in advance, and inject a cooling medium such as deionized water, ultrapure water, or the like.

In one embodiment, the first cover plate and the second cover plate are made of any one of pure copper, copper alloy, stainless steel, aluminum alloy, titanium metal, titanium alloy, and plastic, wherein the copper alloy may be, for example, red copper, brass, bronze, white copper, or the like. The plastic may be, for example, polytetrafluoroethylene.

Further, the inner surface of the first cover plate 10 and/or the second cover plate 20 includes a hydrophobic structure layer 41 and a hydrophilic structure layer 42. In one embodiment, the hydrophobic structure layer 41 is disposed on the inner surface of the first cover plate 10, and the hydrophilic structure layer 42 is disposed on the inner surface of the second cover plate 20.

The hydrophobic structure layer 41 is obtained by performing surface hydrophobization treatment on the first cover plate and/or the second cover plate and/or the capillary structure after etching or deposition or film layer treatment. Illustratively, the etching solution includes a ferric sulfate solution and a sulfuric acid solution. The stearic acid solution may be, for example, an ethanol solution of stearic acid, and the thickness of the hydrophobic structure layer 31 is 0.001 to 0.2mm, and preferably, the thickness of the hydrophobic structure layer 41 is 0.001 to 0.1 mm.

The deposition may be, for example, chemical vapor deposition, physical vapor deposition, or the like, and the film treatment may include any one of electroplating, chemical acid cleaning, and chemical alkali cleaning.

The hydrophilic structure layer 42 is obtained by sintering a porous medium made of a metal material, such as copper or a copper alloy. The porous medium may be, for example, a wire mesh, copper fibers, or the like. In this embodiment, the porous medium is a copper wire mesh, and the diameter of the wire mesh is 200-450 mesh. And during sintering treatment, controlling the silk screen to be sintered for 3-4 hours at the high temperature of 800-890 ℃, wherein the thickness of the hydrophilic structure layer formed after sintering is 0.03-0.2 mm, and preferably, the thickness of the hydrophilic structure layer is 0.05-0.2 mm.

It can be understood that the hydrophilic structural layer 42 is bonded to the opposite surfaces of the first cover plate 10 and the second cover plate 20 by sintering, so that the position of the hydrophilic structural layer 42 is prevented from being changed during use, and the stability of the product operation is ensured. In other embodiments, the copper mesh can be placed in the sealed cavity 40 without any connection processing, so that the influence on the soaking plate caused by the processing in the sintering, hot welding or cold pressing modes is avoided, and the structural stability of the soaking plate is ensured.

In the present embodiment, the thicknesses of the first cover plate 10 and the second cover plate 20 are both less than or equal to 0.2 mm. The first cover plate 10 and the second cover plate 20 are subjected to diffusion welding or brazing or laser welding, and the overall thickness of the soaking plate is 0.1-0.4 mm.

Fig. 4 to 8 respectively show a structural schematic diagram of an ultrathin soaking plate provided in the embodiment of the present application.

Fig. 4 shows a schematic structural diagram of another ultra-thin soaking plate provided by the embodiment of the application. The hydrophobic structure layer 41 and the hydrophilic structure layer 42 are spliced and arranged on the inner surface of the first cover plate and/or the second cover plate. As shown in fig. 4, a hydrophobic structure layer 41 is disposed on an inner surface of the first cover plate 10, and the hydrophobic structure layer 41 and the hydrophilic structure layer 42 are spliced to be disposed on an inner surface of the second cover plate 20. The first cover plate 10 is adjacent to the condensation zone and the second cover plate 20 is adjacent to the evaporation zone. In other embodiments, the hydrophobic structure layer 41 and the hydrophilic structure layer 42 may also be spliced to the inner surface of the second cover plate 20 according to the position of the heat source. As shown in fig. 5a to 5c, the hydrophobic structure layer 41 and the hydrophilic structure layer 42 may be spliced partially, fully, at intervals, etc. The areas of the hydrophobic structure layer 41 and the hydrophilic structure layer 42 may be equal or different, and as shown in fig. 6, the thickness of each hydrophobic structure layer 41 and the thickness of each hydrophilic structure layer 42 may be the same or different.

Fig. 9 shows a schematic structural diagram of another ultra-thin soaking plate provided by the embodiment of the application. As shown in fig. 9, the hydrophobic structure layer 41 and the hydrophilic structure layer 42 are stacked on the inner surface of the first cover plate and/or the second cover plate. In the present embodiment, the hydrophobic structure layer 41 and the hydrophilic structure layer 42 are stacked at intervals. The areas of the hydrophobic structure layer 41 and the hydrophilic structure layer 42 may be equal or different, and the thickness of each hydrophobic structure layer 41 and each hydrophilic structure layer 42 may be the same or different. In the present embodiment, the hydrophobic structure layer 41 and the hydrophilic structure layer 42 are stacked at intervals.

Further, a capillary structure 30 is disposed in the sealed cavity 40 of the soaking plate, specifically, the capillary structure 30, the first cover plate 10 and the second cover plate 20 may be disposed in parallel, or may be disposed according to design requirements, for example, disposed on the supporting structure in a surrounding manner, which is not limited herein. The capillary structure 30 includes a hydrophobic structure layer and a hydrophilic structure layer. For example, a part of the copper fiber with the capillary structure may be placed in an ethanol solution of stearic acid, and subjected to surface hydrophobization treatment, so that the capillary structure forms a hydrophobic structure layer, and the rest of the untreated copper fiber is a hydrophilic structure layer. Illustratively, the capillary structure 30 may be provided on an inner surface of the first cover plate 10 and/or the second cover plate 20. The capillary structure 30 includes the hydrophobic structure layer 41 and the hydrophilic structure layer 42 which are stacked or spliced.

The capillary structure 30 is filled with a cooling medium, which may be, for example, deionized water, methanol, acetone, or the like, and the heat dissipation of the vapor chamber can be realized by gas-liquid two-phase change of the working medium. The specific heat dissipation principle and the heat dissipation path are as described in the above introduction.

The sealed cavity 40 of the soaking plate is provided with an opening communicated with the outside. The opening can be a liquid injection port or a vacuum pumping port. And cooling medium is injected into the sealed cavity 40 through the opening, the sealed cavity 40 is vacuumized through the opening, and then the opening is sealed, so that the sealed cavity 40 is in a vacuum negative pressure state. When the inside of the sealed cavity 40 is vacuumized, the injected cooling medium is in a negative pressure state, and once the cooling medium is heated in the evaporation area, a gasification phenomenon occurs. The volume of the gasified cooling medium is increased and the gasified cooling medium is filled in the whole cavity, the heat dissipated by the gaseous cooling medium is liquefied into the liquid cooling medium in the cooling area, and the liquefied cooling medium returns to the evaporation area again by virtue of the capillary structure 30. This creates a cycle of heat transfer within the sealed housing 40.

As shown in fig. 10, the shapes, sealing forms, connection manners, etc. of the first cover plate 10 and the second cover plate 20 can be designed and modified according to actual needs.

In one embodiment, the cooling medium is deionized water or ultrapure water. Understandably, water is used as the most common cooling medium, the production cost is low, the manufacture is simple, the production cost of the whole soaking plate is reduced, and the water is safer and more reliable compared with methanol, acetone and the like.

Fig. 11 is a schematic structural view of another ultra-thin soaking plate according to an embodiment of the present disclosure, and as shown in fig. 11, the soaking plate 100 further includes a supporting structure 50, where the supporting structure 50 is disposed in the sealed cavity 40 of the casing 110 and is used for maintaining the shape of the casing 110, and the supporting structure 50 abuts between the first cover plate 10 and the second cover plate 20.

The support structure 50 extends from the inner surface of the housing 110 toward the inner space of the housing 110. The channels between the support structures 50 are vapor channels and/or capillary structures. It is to be understood that the support structure can be used to resist deformation of the vapor chamber due to internal and external atmospheric pressure differences and other external forces, so as to prevent the vapor channels and capillary structures from collapsing and causing failure of the vapor chamber.

Specifically, the supporting structures 50 are disposed on the second cover plate 20, the supporting structures 50 are distributed on the second cover plate 20 in an array manner, and when the first cover plate 10 and the second cover plate 20 are hermetically connected to form the sealed cavity 40, the supporting structures 50 form a protective effect of support in the sealed cavity 40, so as to prevent the sealed cavity 40 of the soaking plate 100 from being deformed due to compression. In order to ensure that the supporting structure 50 can perform a supporting and shaping function well, the height of the supporting structure 50 is equal to the height of the sealed cavity 40. Meanwhile, the array distribution of the supporting structures 50 is beneficial to the lightweight design of the vapor chamber, the uniform distribution of the mass of the vapor chamber and the design control of the whole gravity center of the electronic equipment.

The support structure 50 may be machined directly onto the first cover plate or the second cover plate. That is, the supporting structure 50 and the casing 110 are an integrated structure, and the supporting structure 50 is, for example, a plurality of pillars or bumps arranged in an array. Specifically, the first cover plate 10 and the second cover plate 20 are manufactured by etching, the second material layer 12 of the first cover plate 10 is subjected to etching treatment to form a concave surface, and the second material layer 12 of the second cover plate 20 is subjected to etching treatment to form pillars arranged in an array, wherein the pillars are the support structures 50. The support structure 50 obtained by the subtractive processing through the etching process can greatly ensure the connection stability between the support structure 50 and the second cover plate 20, avoid the bonding or welding process between the support structure and the second cover plate, and simplify the processing flow. It is understood that in the present embodiment, the material of the supporting structure 50 is copper or copper alloy, and the strength of the whole soaking plate can be ensured by matching with the high-strength shell.

The supporting structure 50 may also be separately prepared and then fixedly connected to the first cover plate or the second cover plate by welding or the like. Specifically, the second cover plate 20 is processed by stamping, the plate of the second cover plate 20 is first stamped and then reversely stretched to form a recessed area, and finally the support structures 50 are welded and fixed to the second cover plate 20 to form the support structures 50 uniformly arranged in an array. In the present embodiment, the shape of the supporting structure 50 is not limited, and may be, for example, a cylinder, a square, a cone, etc., and the plurality of supporting structures 50 may also be a mixed design of the above shapes, which is not limited herein.

The embodiment of the application also provides a preparation method of the ultrathin soaking plate, which comprises the following steps:

step S01, the first cover plate and the second cover plate are cleaned and dried, and then are etched or deposited or processed on the surface of the film layer; wherein the etching treatment comprises any one of laser etching or chemical etching, and the film layer treatment comprises any one of electroplating, chemical acid washing and chemical alkali washing;

step S02, soaking the inner surface of the first cover plate and/or the second cover plate in a stearic acid solution, and self-assembling for 8-10 hours at 25-40 ℃ to obtain a hydrophobic structure layer;

step S03, sintering the porous medium made of the metal material at the high temperature of 800-890 ℃ for 3-4 hours to form a hydrophilic structure layer on the inner surface of the first cover plate and/or the second cover plate;

step S04, buckling the first cover plate and the second cover plate to form a cavity with an opening, and welding in a protective atmosphere;

and step S05, injecting a cooling medium into the cavity through the opening, extracting air in the cavity through the opening to enable the cavity to be in a negative pressure state, sealing the opening, and welding and sealing to manufacture the ultrathin soaking plate.

The hydrophilic structural layer can enhance the capillary performance of the ultrathin soaking plate and improve the reflux speed of the cooling medium; the hydrophobic structure layer can effectively prevent the formation of a liquid film, improve the gasification core density, reduce the wall surface superheat degree, simultaneously reduce the radial thermal resistance of the ultrathin soaking plate, and improve the temperature equalizing performance and the heat transfer performance of the ultrathin soaking plate.

The first cover plate and the second cover plate are made of any one of pure copper, copper alloy, stainless steel, aluminum alloy, titanium metal, titanium alloy or plastic. The copper alloy may be, for example, copper, brass, bronze, cupronickel, etc., and the plastic may be, for example, polytetrafluoroethylene.

In one embodiment, step S01 includes:

and immersing the first cover plate and the second cover plate into an absolute ethyl alcohol solution, carrying out ultrasonic cleaning, removing oil stains on the surface of the cover plate, and drying. The ultrasonic cleaning time is 5-10 minutes, and oil stains on the surface of the cover plate are removed.

And arranging the dried first cover plate and the dried second cover plate in an etching solution for etching for 35-40 minutes, wherein the etching solution comprises a ferric sulfate solution and a sulfuric acid solution. Specifically, the etching solution is 3.5% Fe by mass₂(SO4)₃75% of H by mass₂SO₄And deionized water in a volume ratio of 1:3: 10.

In another embodiment, step S01 includes:

And covering metal layers on the surfaces of the first cover plate and the second cover plate after drying in a vacuum coating or electroplating coating mode, wherein the metal layers are made of copper or titanium.

And cleaning the first cover plate and the second cover plate after the film layer treatment by using deionized water and then drying.

For example, a metal layer is formed on a first cover plate and a second cover plate of plastic through film layer treatment, and then a hydrophobic structure layer is obtained through surface hydrophobic treatment.

Further, in step S02, the stearic acid solution may be, for example, an ethanol solution of stearic acid, and the concentration of the stearic acid solution is 0.1 to 0.25 mol/L. The thickness of the hydrophobic structure layer 31 is 0.001-0.2 mm, preferably, the thickness of the hydrophobic structure layer 31 is 0.001-0.1 mm, so that the overall soaking plate is thinner.

In step S03, the porous medium may be, for example, a wire mesh, copper fibers, or the like. In this embodiment, the porous medium is a copper wire mesh, and the diameter of the wire mesh is 200-450 mesh. And during sintering treatment, controlling the silk screen to be sintered for 3-4 hours at the high temperature of 800-980 ℃, wherein the thickness of the hydrophilic structure layer formed after sintering is 0.03-0.2 mm, and preferably, the thickness of the hydrophilic structure layer is 0.05-0.25 mm.

Further, as shown in fig. 12 to 13, step S04 includes:

step S041, immersing the first cover plate 10 and the second cover plate 20 in an absolute ethyl alcohol solution, and cleaning for 5-10 min by using ultrasonic waves to remove oil stains on the surfaces;

step S041, placing the second cover plate 20 into a concave graphite mold 80, and then inserting one end of a copper pipe into the concave graphite mold, wherein the surface of the copper pipe is coated with copper paste for forming an opening for vacuumizing and injecting liquid;

step S042, the first cover plate 10 is placed in the convex graphite grinding tool 90 and is attached to the second cover plate, and finally the convex graphite grinding tool and the concave graphite grinding tool are pressed together;

s043, applying extra pressure to the graphite grinding tool by using the deformed clamp to prevent the upper cover plate and the lower cover plate from deforming and dislocating in the diffusion welding process;

step S044, placing the graphite grinding tool into a high-temperature sintering furnace for diffusion welding, wherein the temperature of the diffusion welding is 850-920 ℃, in order to prevent oxidation, the welding is carried out in a protective atmosphere, the protective atmosphere is a mixed gas of hydrogen and nitrogen, and the volume ratio of the hydrogen to the nitrogen is 2: 98, respectively;

and step S045, after the diffusion welding is finished, loosening the deformed clamp.

Further, the cooling medium employed in step S05 is ultrapure water. Understandably, water is used as the most common cooling medium, the production cost is low, the manufacture is simple, the production cost of the whole soaking plate is reduced, and the water is safer and more reliable compared with methanol, acetone and the like.

The embodiment also provides electronic equipment which comprises a working module, wherein the heat dissipation module comprises the ultrathin soaking plate, and the ultrathin soaking plate is used for dissipating heat of the working module. An electronic device such as a mobile phone, a tablet computer, a wearable device (e.g., a smart watch), etc., is not limited herein.

The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An ultrathin soaking plate comprises a first cover plate and a second cover plate; the first cover plate and the second cover plate are connected in a sealing mode to form a sealed cavity, a negative pressure environment is arranged in the sealed cavity, and a capillary structure and a cooling medium are arranged in the sealed cavity; the hydrophobic structure layer is obtained by performing surface hydrophobic treatment on the first cover plate and/or the second cover plate and/or the capillary structure after etching or deposition or film layer treatment.

2. The ultra-thin vapor chamber of claim 1, wherein the first cover plate and the second cover plate are made of any one of pure copper, copper alloy, stainless steel, aluminum alloy, titanium metal, titanium alloy or plastic.

3. The ultrathin soaking plate according to claim 1, wherein the thickness of the hydrophobic structure layer is 0.001-0.2 mm.

4. The ultrathin soaking plate according to claim 1, wherein the hydrophilic structure layer is obtained by sintering a porous medium made of a metal material, and the thickness of the hydrophilic structure layer is 0.03-0.2 mm.

5. The ultrathin soaking plate according to claim 1, wherein the first cover plate and the second cover plate are diffusion-welded, brazed or laser-welded, and the thickness of the welded soaking plate is 0.1-0.4 mm.

6. The ultrathin soaking plate according to any one of claims 1 to 5, wherein the hydrophobic structure layer is arranged on the inner surface of the first cover plate, and the hydrophilic structure layer is arranged on the inner surface of the second cover plate.

7. The ultrathin soaking plate according to any one of claims 1 to 5, wherein the hydrophobic structure layer and the hydrophilic structure layer are spliced or stacked on the inner surface of the first cover plate and/or the second cover plate.

8. The ultrathin soaking plate according to any one of claims 1 to 5, wherein the capillary structure comprises the hydrophobic structure layer and the hydrophilic structure layer which are arranged in a stacked or spliced manner.

9. The ultra-thin vapor chamber of claim 1, wherein the cooling medium is deionized water or ultra-pure water.

10. The ultra-thin vapor chamber of claim 1, further comprising a support structure disposed within the sealed cavity of the shell for maintaining the shape of the shell, the support structure abutting between the first cover plate and the second cover plate.

11. A preparation method of an ultrathin soaking plate is characterized by comprising the following steps:

12. The method of claim 11, wherein the first cover plate and the second cover plate are made of any one of pure copper, copper alloy, stainless steel, aluminum alloy, titanium metal, titanium alloy, or plastic.

13. The method of claim 11, wherein the first cover plate and the second cover plate are cleaned and dried and then etched, comprising:

14. The method of manufacturing an ultra-thin soaking plate according to claim 11, wherein the stearic acid solution is 0.1 to 0.25 mol/L.

15. The method for preparing the ultrathin soaking plate according to claim 11, wherein the thickness of the soaking plate is 0.1-0.4 mm.

16. The method for preparing the ultrathin soaking plate according to claim 11, wherein the thickness of the hydrophobic structure layer is 0.001-0.2 mm.

17. The preparation method of the ultrathin soaking plate according to claim 11, wherein the porous medium is a copper wire mesh, the pore diameter of the wire mesh is 200-450 meshes, and the thickness of the hydrophilic structural layer is 0.03-0.2 mm.

18. The method of claim 11, wherein the cooling medium is deionized water or ultrapure water.

19. The method for preparing an ultra-thin vapor chamber according to claim 11, wherein the protective atmosphere is a mixed gas of hydrogen and nitrogen.

20. An electronic device comprising a working module and a heat dissipation module, the heat dissipation module comprising the ultra-thin thermal soaking plate according to any one of claims 1 to 10, the ultra-thin thermal soaking plate being for dissipating heat from the working module.