Anti-expansion vapor chamber and manufacturing method thereof

Abstract

The invention provides an anti-expansion vapor chamber and a manufacturing method thereof.The anti-expansion vapor chamber comprises an upper shell plate, a first liquid absorption core, a lower shell plate, a second liquid absorption core and a working medium, the upper shell plate is connected with the lower shell plate, and the upper shell plate and the lower shell plate are each provided with a groove used for forming an upper inner cavity and a lower inner cavity; a plurality of first supporting columns are distributed in the groove of the upper shell plate, and a plurality of through holes corresponding to the first supporting columns are distributed in the first wick, so that the first supporting columns penetrate through the through holes to mount the first wick in the upper inner cavity of the upper shell plate; a plurality of second supporting columns matched with the first supporting columns are distributed in the groove of the lower shell plate, and a plurality of through holes corresponding to the second supporting columns are distributed in the second wick, so that the two supporting columns penetrate through the through holes to mount the second wick in the lower inner cavity of the lower shell plate; the working medium is phase change liquid flowing in the groove, and heat of the upper shell plate and the lower shell plate is dispersed to the vapor chamber. The vapor chamber provided by the invention has relatively high heat dissipation performance, and can overcome the problem of insufficient anti-expansion performance of the vapor chamber in battery heat dissipation.

Description

Technical Field

[0001] The present invention relates to the technical field of battery heat dissipation, and in particular to an anti-expansion vapor chamber and a manufacturing method thereof. Background Art

[0002] The battery car and power energy storage industries are developing rapidly. In order to ensure that the battery system can maintain better operating conditions and relatively longer service life in various environments, battery temperature control is particularly important.

[0003] As a phase change device with high heat transfer and fast startup characteristics, the vapor chamber has been applied in various industries. In particular, the advent of ultra-thin and miniaturized vapor chambers in recent years has opened up new channels for more diversified applications of vapor chambers. However, as the vapor chamber becomes thinner, its structural strength problem has also begun to become the focus of attention.

[0004] Ultra-thin vapor chambers expand rapidly in a vacuum or high-temperature environment due to the difference in internal and external pressures, which seriously affects the assembly and application of ultra-thin vapor chambers in many fields. For example, in the field of batteries and motors, the vapor chamber needs to undergo vacuum and high-temperature packaging during the assembly process. Similarly, in aerospace applications, absolute vacuum often puts the vapor chamber at risk of direct failure.

[0005] Therefore, how to ensure that the heat spreader can still maintain its structural anti-expansion strength during the ultra-thinning process is an issue that needs to be urgently addressed. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention proposes an anti-expansion vapor chamber and a manufacturing method thereof, which can overcome the problem of insufficient anti-expansion performance of the vapor chamber in battery heat dissipation.

[0007] A first aspect of the embodiments of the present disclosure provides an anti-expansion vapor chamber, comprising:

[0008] An upper shell plate, a first liquid absorbent core, a lower shell plate, a second liquid absorbent core and a working medium, wherein the upper shell plate and the lower shell plate are connected, and the upper shell plate and the lower shell plate are both provided with grooves for forming an upper inner cavity and a lower inner cavity;

[0009] A plurality of first support columns are distributed in the groove of the upper shell plate, and a plurality of through holes corresponding to the first support columns are distributed on the first absorbent core, so that the first support columns pass through the through holes to install the first absorbent core in the upper inner cavity of the upper shell plate;

[0010] A plurality of second support columns matched with the first support columns are distributed in the groove of the lower shell plate, and a plurality of through holes corresponding to the second support columns are distributed on the second absorbent core, so that the two support columns pass through the through holes to install the second absorbent core in the lower inner cavity of the lower shell plate;

[0011] The working medium is a phase-change liquid flowing in the groove, which disperses the heat of the upper shell plate and the lower shell plate to the heat diffusion plate.

[0012] In one embodiment of the present disclosure, welding edges and injection sections are distributed around the first support column and the second support column, and the height of the welding edges and the injection section is the same as the height of the adjacent support column.

[0013] In one embodiment of the present disclosure, the liquid wick and the shell plate are phase change metal materials or ceramic materials.

[0014] In one embodiment of the present disclosure, the first support column and the second support column are cylindrical, polygonal prism-shaped, and irregular prism-shaped.

[0015] In one embodiment of the present disclosure, the absorbent core is a sheet-like wire mesh structure, including at least one layer of metal wire mesh.

[0016] In one embodiment of the present disclosure, the thickness of the wick is not higher than the height of the support column, the inner diameter of the through hole is not less than the maximum outer diameter of the support column, and the shape of the through hole is compatible with the cross-sectional shape of the support column passing through the through hole.

[0017] In one embodiment of the present disclosure, a capillary structure for enhancing the liquid absorption performance is provided on the liquid absorbent core.

[0018] In one embodiment of the present disclosure, the thickness of the heat spreader formed by bonding the upper shell plate and the lower shell plate is no more than 1 mm.

[0019] In one embodiment of the present disclosure, the first support columns and the second support columns are arranged in an array in the grooves of the upper shell plate and the lower shell plate, respectively.

[0020] According to a second aspect of the embodiments of the present disclosure, a method for manufacturing an anti-expansion vapor chamber is provided, comprising the following steps:

[0021] Step 1: Process the upper shell plate and the lower shell plate by etching or stamping, respectively process grooves forming the upper inner cavity and the lower inner cavity on the surface of the upper shell plate and the lower shell plate, then form support columns in the grooves, and retain welding edges and injection sections around the support columns;

[0022] Step 2: Processing the liquid absorbent core by a stamping process, and retaining through holes corresponding to the shell plate support columns on the liquid absorbent core;

[0023] Step 3: The liquid absorbent core is sleeved in the inner cavity of the matching upper shell plate or lower shell plate, and the liquid absorbent core and the matching shell plate are connected by high-temperature sintering after being pressed by a graphite mold, and the high-temperature sintering temperature is not less than 650°C;

[0024] Step 4: Process the injection section into an injection groove through a stamping process, splice the upper shell plate and the lower shell plate, place them in a graphite mold, and connect them through a welding process to form a heat sink;

[0025] Step 5: Pour the working fluid into the upper inner cavity and the lower inner cavity formed by the upper shell plate and the lower shell plate through the liquid injection tank, and then evacuate the inner cavity of the heat spreader and complete the manufacture of the heat spreader through a sealing welding process.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) The present invention improves the structural design and process of the welding between the support columns of the heat spreader, which can improve the anti-expansion structural strength and fatigue strength of the heat spreader in the battery heat dissipation application scenario, and effectively ensure its heat transfer stability and service life.

[0028] (2) The present invention can be applied to various extreme environments including vacuum environments and high-temperature environments, and has better process adaptability and usage stability, especially for scenarios such as aerospace fields and battery motors.

[0029] (3) The present invention distributes heat evenly to various positions of the heat spreader through two inner cavities filled with phase change fluids, thereby meeting heat dissipation requirements in different heat dissipation scenarios. The dual inner cavity design evenly transfers heat to the shell plate through the liquid channel of the wick and the air channel of the inner cavity to achieve high-efficiency heat dissipation.

[0030] (4) The present invention ensures ultra-thinness of the heat spreader while improving the anti-expansion performance of the heat spreader, and can be applied to most application scenarios that have requirements for the thickness of the heat spreader, thereby increasing the application scope of the heat spreader and improving the practicality of the heat spreader. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A three-dimensional exploded view of an anti-expansion vapor chamber according to the present invention;

[0033] Figure 2A schematic diagram of an upper shell plate in an anti-expansion soaking plate of the present invention;

[0034] Figure 3 The figure is a cross-sectional view of an anti-expansion vapor chamber according to the present invention.

[0035] Figure identification: 1-upper shell plate, 2-lower shell plate, 3-first liquid absorbent core, 4-second liquid absorbent core, 5-first support column, 6-second support column, 7-woven belt. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", "fourth", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Embodiment 1

[0040] See also Figures 1 to 3 The embodiment of the present invention discloses an anti-expansion soaking plate, comprising: an upper shell plate 1, a first liquid wick 3, a lower shell plate 2, a second liquid wick 4 and a working medium, wherein the upper shell plate 1 and the lower shell plate 2 are connected, and the upper shell plate 1 and the lower shell plate 2 are both provided with grooves for forming an upper inner cavity and a lower inner cavity;

[0041] It should be noted that compared to the heat spreader used in the field of chip heat dissipation, which needs to be laid above the chip as the heat source, the chip heat can be evenly transferred to the shell plate of the heat spreader through an inner cavity that can circulate phase change working fluid to release heat, and the thickness of the heat spreader itself does not affect the chip heat dissipation performance, especially in the high-temperature chip heat dissipation scenario in military scenarios. The core is the anti-expansion performance problem, without considering the ultra-thinness of the heat spreader. In this application, the anti-expansion heat spreader is used in the field of battery heat dissipation. In addition to the improvement of anti-expansion performance, it is also necessary to consider the ultra-thinness of the heat spreader so that it can be installed between batteries. Therefore, the design of two inner cavities can ensure that the heat spreader is ultra-thin and a full range of heat absorption and heat release processes can be achieved. At the same time, while retaining the liquid and air channel structures of the heat spreader, the support columns are welded by welding methods such as diffusion welding, single-point brazing, reflow soldering, etc., to ensure that the processed heat spreader has high anti-expansion performance.

[0042] In one embodiment of the present disclosure, the thickness of the heat spreader formed by bonding the upper shell plate 1 and the lower shell plate 2 is no greater than 1 mm.

[0043] It should be noted that in the field of battery heat dissipation, the phase change working fluid absorbs the battery heat and then releases the heat through the heat spreader shell and the condensation end. The heat spreader needs to be installed between adjacent batteries, and its thickness will affect the heat dissipation efficiency. If the heat spreader's anti-expansion performance is insufficient, the heat spreader will also expand and rapid heat transfer cannot be achieved. Therefore, ultra-thin heat spreaders can effectively dissipate heat when facing battery heat dissipation, and the thinner the thickness, the higher the heat dissipation efficiency.

[0044] A plurality of first support columns 5 are distributed in the groove of the upper shell plate 1, and a plurality of through holes corresponding to the first support columns 5 are distributed on the first absorbent core 3, so that the first support columns 5 pass through the through holes to install the first absorbent core 3 in the upper inner cavity of the upper shell plate 1;

[0045] In one embodiment of the present disclosure, welding edges and injection sections are distributed around the first support column 5 and the second support column 6, and the height of the welding edges and the injection section is the same as the height of the adjacent support columns.

[0046] In an embodiment of the present disclosure, the first support column 5 and the second support column 6 are cylindrical, polygonal prism-shaped, and irregular prism-shaped.

[0047] It should be noted that, as known to those skilled in the art, in actual production, the cross-sectional shapes of the support columns and through holes can be adjusted according to actual application requirements, as long as the installation requirements for the wick and the welding of the upper and lower shell plates are met, as long as heat transfer through the liquid channels and air channels in the inner cavity of the heat spreader can be achieved.

[0048] A plurality of second support columns 6 matching the first support columns 5 are distributed in the groove of the lower shell plate 2, and a plurality of through holes corresponding to the second support columns 6 are distributed on the second absorbent core 4, so that the two support columns pass through the through holes to install the second absorbent core 4 in the lower inner cavity of the lower shell plate 2;

[0049] In one embodiment of the present disclosure, the first support columns 5 and the second support columns 6 are arranged in an array in the grooves of the upper shell plate 1 and the lower shell plate 2, respectively.

[0050] Further, such as Figure 3 As shown, when designing the support column and the wick, the maximum outer diameter D of the support column needs to be larger than the inner diameter of the through hole of the wick. Preferably, the design of the support column being narrow at the top and wide at the bottom can effectively increase the volume of the inner cavity air duct and achieve faster heat dissipation.

[0051] Furthermore, it is known to those skilled in the art that when designing the arrangement of the support columns, it is sufficient to ensure that the root outer diameter, top inner diameter, shape, position, and number of the support columns in the grooves of the upper and lower shell plates are one-to-one corresponding. The arrangement can be adjusted according to actual needs, and the sizes of the support columns can also be different (for example, the length of the first support column can be different from the length of the second support column, then the thickness of the upper shell plate and the thickness of the lower shell plate need to be adjusted to ensure that the length of the support column is adapted to the thickness of the shell plate), as long as the welding surface diameters of the first support column and the second support column are the same.

[0052] The working medium is a phase-change liquid flowing in the groove, which disperses the heat of the upper shell plate 1 and the lower shell plate 2 to the heat spreader.

[0053] It should be noted that the working fluid can be a liquid substance with phase change heat transfer performance, which can achieve the effect of rapid heat dissipation of the heat spreader. Those skilled in the art will easily know that anhydrous ethanol, acetone, ionized water, and methanol can all be used as working fluids.

[0054] In one embodiment of the present disclosure, the liquid wick and the shell plate are phase change metal materials or ceramic materials.

[0055] It should be noted that the material of the shell plate is a metal material with phase change heat transfer performance such as copper, stainless steel, aluminum, etc. or a ceramic material, among which copper is the preferred material. Similarly, the wick can also be a metal material with phase change heat transfer performance such as copper, stainless steel, aluminum, etc., among which copper is the preferred material.

[0056] In one embodiment of the present disclosure, the absorbent core is a sheet-like wire mesh structure, including at least one layer of metal wire mesh.

[0057] In one embodiment of the present disclosure, the thickness of the wick is not higher than the height of the support column, the inner diameter of the through hole is not less than the maximum outer diameter of the support column, and the shape of the through hole is compatible with the cross-sectional shape of the support column passing through the through hole.

[0058] In one embodiment of the present disclosure, a capillary structure for enhancing the liquid absorption performance is provided on the liquid absorbent core.

[0059] It should be noted that the liquid wick can be a multi-layer screen such as a copper screen sintered, the screen mesh number is not less than 250 meshes, the thickness is 0.01-0.04mm, and the screen layer number is 1-10 layers, such as Figure 2 As shown, under the premise that the original capillary structure of the absorbent core can effectively absorb the working fluid, adding a capillary structure (such as a woven mesh, the woven mesh material is preferably copper) that can enhance the absorbent performance on the surface of the wire mesh can further increase the overall absorbent performance of the absorbent core and improve the heat dissipation efficiency.

[0060] The present invention improves the structure design and process of the welding between the support columns of the heat spreader, which can improve the anti-expansion structural strength and fatigue strength of the heat spreader in the battery heat dissipation application scenario, and effectively ensure its heat transfer stability and service life. The heat is evenly distributed to various positions of the heat spreader through two inner cavities filled with phase change working fluids, and the heat dissipation requirements can be met in different heat dissipation scenarios. The heat is evenly transferred to the shell plate through the liquid channel of the wick and the air channel of the inner cavity through the double inner cavity design to achieve efficient heat dissipation. The ultra-thinness of the heat spreader is ensured on the premise of improving the anti-expansion performance of the heat spreader, which can be applied to most application scenarios that require the thickness of the heat spreader, increase the scope of application of the heat spreader, and improve the practicality of the heat spreader. It can be applied to various extreme environments including vacuum environment and high temperature environment, especially for aerospace fields, battery motors and other scenarios, which have better process adaptability and use stability.

[0061] Embodiment 2

[0062] The embodiment of the present invention discloses a method for manufacturing an anti-expansion vapor chamber, comprising the following steps:

[0063] Step 1: Process the upper shell plate and the lower shell plate by etching or stamping, respectively process grooves forming the upper inner cavity and the lower inner cavity on the surface of the upper shell plate and the lower shell plate, then form support columns in the grooves, and retain welding edges and injection sections around the support columns; it should be noted that the processing technology of the shell plate can also include laser lithography, machining and other methods.

[0064] Step 2: Process the absorbent core by stamping process, and retain the through hole corresponding to the shell plate support column on the absorbent core; when processing the absorbent core, in order to enable the absorbent core to meet the requirements of absorbent performance, other cutting processes such as laser lithography and wire cutting can also be used to process the absorbent core.

[0065] Step 3: Place the liquid absorbent core in the inner cavity of the matching upper shell plate or lower shell plate, press it with a graphite mold and then perform high-temperature sintering to connect the liquid absorbent core and the matching shell plate. The high-temperature sintering temperature is not less than 650°C; the sintering adopts the gas reduction atmosphere sintering method, and the sintering temperature must be not less than 650°C.

[0066] Step 4: Process the injection section into an injection groove through a stamping process, splice the upper shell plate and the lower shell plate, and place them in a graphite mold for connection through a welding process to form a heat spreader. Furthermore, the weld edge, support column and raised plate edge around the groove processed during the welding process are the main welding points of the welding process, especially the welding of the support column is the key to achieving the anti-expansion performance of the heat spreader. When welding, in addition to the preferred diffusion welding, the use of support column single-point brazing, reflow soldering and other welding methods can also ensure the anti-expansion performance of the support column. For example, when brazing is used, a layer of brazing solder is applied to the weld edge of the shell plate and the injection section, and then the two pieces of shell plates with wire mesh are fitted up and down and placed in a graphite mold for 650°C high-temperature brazing. After brazing, the heat spreader as a whole is subjected to secondary resistance welding to ensure that each pair of upper and lower support columns can be tightly welded.

[0067] Step 5: Pour the working fluid into the upper inner cavity and the lower inner cavity formed by the upper shell plate and the lower shell plate through the liquid injection tank, and then evacuate the inner cavity of the heat spreader and complete the manufacture of the heat spreader through a sealing welding process.

[0068] Through the above steps, an anti-expansion vapor chamber described in the present invention can be obtained. When the anti-expansion vapor chamber is in operation, it is placed between adjacent batteries, and the phase change working fluid passing through the two inner cavities from two directions is heated and vaporized, and heat is released through the condensation end. The phase change working fluid circulates back and forth along the liquid channels in the upper and lower inner cavities of the upper and lower shell plates, and at the same time cooperates with the air channels between the support columns and the adjacent liquid wicks to complete phase change cooling, reduce the battery temperature, and prevent the expansion of the vapor chamber.

[0069] The present invention improves the structure design and process of the welding between the support columns of the heat spreader, which can improve the anti-expansion structural strength and fatigue strength of the heat spreader in the battery heat dissipation application scenario, and effectively ensure its heat transfer stability and service life. The heat is evenly distributed to various positions of the heat spreader through two inner cavities filled with phase change working fluids, and the heat dissipation requirements can be met in different heat dissipation scenarios. The heat is evenly transferred to the shell plate through the liquid channel of the wick and the air channel of the inner cavity through the double inner cavity design to achieve efficient heat dissipation. The ultra-thinness of the heat spreader is ensured on the premise of improving the anti-expansion performance of the heat spreader, which can be applied to most application scenarios that require the thickness of the heat spreader, increase the scope of application of the heat spreader, and improve the practicality of the heat spreader. It can be applied to various extreme environments including vacuum environment and high temperature environment, especially for aerospace fields, battery motors and other scenarios, which have better process adaptability and use stability.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-expansion vapor chamber, used for battery heat dissipation, characterized in that: include: An upper shell plate, a first liquid absorbent core, a lower shell plate, a second liquid absorbent core and a working medium, wherein the upper shell plate and the lower shell plate are connected, and the upper shell plate and the lower shell plate are both provided with grooves for forming an upper inner cavity and a lower inner cavity; A plurality of first support columns are distributed in the groove of the upper shell plate, and a plurality of through holes corresponding to the first support columns are distributed on the first absorbent core, so that the first support columns pass through the through holes to install the first absorbent core in the upper inner cavity of the upper shell plate; A plurality of second support columns matched with the first support columns are distributed in the groove of the lower shell plate, and a plurality of through holes corresponding to the second support columns are distributed on the second absorbent core, so that the two support columns pass through the through holes to install the second absorbent core in the lower inner cavity of the lower shell plate; The working medium is a phase-change liquid flowing in the groove, which disperses the heat of the upper shell plate and the lower shell plate to the heat diffusion plate.

2. The anti-expansion vapor chamber according to claim 1, characterized in that: Welding edges and liquid injection sections are distributed around the first supporting column and the second supporting column, and the heights of the welding edges and the liquid injection sections are the same as the heights of adjacent supporting columns.

3. The anti-expansion vapor chamber according to claim 1, characterized in that: The liquid absorbing core and the shell plate are made of phase change metal material or ceramic material.

4. The anti-expansion vapor chamber according to claim 1, characterized in that: The first support column and the second support column are cylindrical, polygonal prism and irregular prism.

5. The anti-expansion vapor chamber according to claim 1, characterized in that: The liquid absorbing core is a sheet-like wire mesh structure, comprising at least one layer of metal wire mesh.

6. The anti-expansion vapor chamber according to claim 1, characterized in that: The thickness of the wick is not higher than the height of the support column, the inner diameter of the through hole is not less than the maximum outer diameter of the support column, and the shape of the through hole is compatible with the cross-sectional shape of the support column passing through the through hole.

7. The anti-expansion vapor chamber according to claim 1, characterized in that: The liquid absorbent core is provided with a capillary structure for enhancing the liquid absorption performance.

8. The anti-expansion vapor chamber according to claim 1, characterized in that: The thickness of the heat spreader formed by the upper shell plate and the lower shell plate is not higher than 1 mm.

9. The anti-expansion vapor chamber according to claim 1, characterized in that: The first support columns and the second support columns are arranged in an array in the grooves of the upper shell plate and the lower shell plate respectively.

10. A method for manufacturing an anti-expansion vapor chamber, comprising the following steps: Step 1: Process the upper shell plate and the lower shell plate by etching or stamping, respectively process grooves forming the upper inner cavity and the lower inner cavity on the surface of the upper shell plate and the lower shell plate, then form support columns in the grooves, and retain welding edges and injection sections around the support columns; Step 2: Processing the liquid absorbent core by a stamping process, and retaining through holes corresponding to the shell plate support columns on the liquid absorbent core; Step 3: The liquid absorbent core is sleeved in the inner cavity of the matching upper shell plate or lower shell plate, and the liquid absorbent core and the matching shell plate are connected by high-temperature sintering after being pressed by a graphite mold, and the high-temperature sintering temperature is not less than 650°C; Step 4: Process the injection section into an injection tank by a stamping process, splice the upper shell plate and the lower shell plate, place them in a graphite mold, and connect them by welding to form a heat sink; Step 5: Pour the working fluid into the upper inner cavity and the lower inner cavity formed by the upper shell plate and the lower shell plate through the liquid injection tank, and then evacuate the inner cavity of the heat spreader and complete the manufacture of the heat spreader through a sealing welding process.

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