Vapor chamber

Abstract

The embodiment of the invention provides a vapor chamber which comprises an upper shell and a lower shell, the upper shell is in a groove shape, the lower shell is in a flat plate shape, and a sealing cavity is formed by the groove of the upper shell and the lower shell; capillary layers are arranged on the inner surface of the upper shell and the inner surface of the lower shell respectively, a plurality of supporting columns are arranged in the sealing cavity, and the two ends of each supporting column are connected to the inner surface of the upper shell and the inner surface of the lower shell respectively; and the plurality of supporting columns are uniformly distributed in the sealing cavity. According to the invention, the structural strength of the vapor chamber is enhanced through the plurality of support columns uniformly distributed in the sealed cavity, the problem of bulging or warping of the vapor chamber in the packaging process in the prior art is solved, the vapor chamber is ensured not to bulge in a high-temperature environment, and the yield of a chip packaging test is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of communications, and in particular, to a vapor chamber. Background Art

[0002] With the development of the electronics industry, semiconductor process nodes are constantly shrinking, and chip power consumption is evolving rapidly. The power density of high-performance chips is getting higher and higher, and the growing non-uniform power consumption leads to hot spots on the chip, causing the chip to overheat.

[0003] At present, more and more vapor chambers are used for heat dissipation of computer and mobile phone chips. However, the vapor chamber has to go through high-temperature reflow soldering in the subsequent packaging process, and the process temperature is as high as 260°C. During this process, the pressure in the sealed cavity of the vapor chamber will increase sharply, causing the vapor chamber to bulge or even rupture. The bulging or warping of the vapor chamber will lead to the failure of chip packaging. Summary of the invention

[0004] An embodiment of the present invention provides a vapor chamber to at least solve the problem of bulging or warping of the vapor chamber during a packaging process in the related art.

[0005] According to one embodiment of the present invention, a vapor chamber is provided, comprising an upper shell and a lower shell.

[0006] The upper shell is groove-shaped, and the lower shell is flat-plate-shaped. The groove of the upper shell and the lower shell form a sealed cavity. The inner surface of the upper shell and the inner surface of the lower shell are respectively provided with capillary layers. A plurality of support columns are provided in the sealed cavity, and the two ends of the plurality of support columns are respectively connected to the inner surface of the upper shell and the inner surface of the lower shell. The plurality of support columns are evenly distributed in the sealed cavity.

[0007] Optionally, the spacing between the circumferences of the multiple support columns is 1 / 8 of the side length of the heat spreader.

[0008] Optionally, the support column is cylindrical or truncated cone in shape.

[0009] Optionally, the outer surface of the support column is a smooth surface or is provided with a capillary structure.

[0010] Optionally, a bottom foot is provided on the lower surface of the lower shell.

[0011] Optionally, the base is a continuous frame structure.

[0012] Optionally, the base foot is integrally formed with the lower shell or the base foot is welded to the lower shell.

[0013] Optionally, the processing methods of the base foot and the lower shell include at least one of the following: brazing, etching, stamping, hot forging, and computer numerical control technology CNC.

[0014] Optionally, the structure of the capillary layer is one of the following: a wire mesh structure, a sintered capillary structure, foam copper, and any combination thereof.

[0015] Optionally, the upper shell or the lower shell is made of copper alloy.

[0016] Optionally, the capillary layer is filled with a liquid working medium, and the liquid working medium includes at least one of the following types: water and methanol.

[0017] In the heat spreader according to some embodiments of the present invention, a plurality of evenly distributed support columns are arranged between the inner surface of the upper shell and the inner surface of the lower shell of the heat spreader, so that the structural strength of the heat spreader is enhanced, ensuring that the heat spreader does not bulge in an environment of high temperature of 260°C and saturated vapor pressure corresponding to 260°C, reducing the surface warping of the heat spreader, improving the yield of chip packaging testing, and solving the problem of bulging or warping of the heat spreader in the packaging process in the related technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a cross-sectional view of a vapor chamber according to an embodiment of the present invention;

[0019] Figure 2 is a top cross-sectional view of a vapor chamber according to an embodiment of the present invention;

[0020] Figure 3 is a cross-sectional view of a vapor chamber according to another embodiment of the present invention;

[0021] Figure 4 is an appearance diagram of a vapor chamber according to an embodiment of the present invention;

[0022] Figure 5 is a footing design diagram according to an embodiment of the present invention;

[0023] Figure 6 4 is a diagram showing the distribution of support columns of a heat spreader according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings and in combination with the embodiments.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0026] In the prior art, the heat spreader is mainly composed of a shell, a capillary structure, a steam chamber and a liquid medium. The lower surface of the heat spreader is usually connected to the chip through a TIM material. When the chip heats up, the liquid medium in the capillary structure absorbs heat and vaporizes into steam, quickly filling the entire cavity. When the gas phase medium is cooled, it will condense, releasing the heat absorbed during evaporation, condensing into a liquid phase medium, and then returning to the evaporation zone through the capillary structure to continue the two-phase flow circulation heat dissipation. Because of the phase change heat transfer involved, the equivalent thermal conductivity of the heat spreader is very high, and it has a strong temperature equalization ability, which can reduce the chip junction temperature.

[0027] However, the heat spreader has to undergo high-temperature reflow soldering during the packaging process. During this process, the pressure in the sealed cavity of the heat spreader will increase sharply, causing the heat spreader to bulge or even rupture. The bulging or warping of the heat spreader will lead to failure of the chip packaging.

[0028] An embodiment of the present invention provides a heat spreader that can be used in heat dissipation elements of high-power chip packages where local hot spots occur. The core concept of the present invention is that a plurality of evenly distributed support columns are arranged between the upper and lower shells of the heat spreader, thereby enhancing the structural strength of the heat spreader and ensuring that the heat spreader does not bulge in an environment of a high temperature of 260°C and a saturated vapor pressure corresponding to 260°C.

[0029] Figure 1 is a cross-sectional view of a vapor chamber according to an embodiment of the present invention, Figure 1 As shown, the heat spreader includes an upper shell 10 and a lower shell 20, the upper shell 10 is groove-shaped, and the lower shell 20 is flat-plate-shaped, and the groove of the upper shell 10 and the lower shell 20 form a sealed cavity; the inner surface of the upper shell 10 and the inner surface of the lower shell 20 are respectively provided with a capillary layer 50, and a plurality of support columns 60 are provided in the sealed cavity, and the two ends of the plurality of support columns 60 are respectively connected to the inner surface of the upper shell 10 and the inner surface of the lower shell 20; the plurality of support columns 60 are evenly distributed in the sealed cavity.

[0030] In an optional embodiment, the capillary layer is filled with a liquid working medium, and the liquid working medium includes at least one of the following types: water and methanol.

[0031] The embodiment of the present invention circulates the liquid working medium in the capillary layer for rapid heat conduction, thus achieving a good heat transfer effect.

[0032] As an example, the selection of the liquid working medium should take into account its wettability with the shell material. For example, the liquid working medium can be water or methanol.

[0033] As an example, the capillary layer 50 may include an upper shell capillary layer 51 and a lower shell capillary layer 52, wherein the capillary layer 52 of the lower shell is filled with liquid working fluid, and the liquid working fluid may be vaporized into a gaseous working fluid and fill the sealed cavity after absorbing the heat transferred by the chip, and the gaseous working fluid liquefies into a liquid working fluid after contacting the capillary layer of the upper shell, and then flows back to the capillary layer of the lower shell along a plurality of support columns, and the liquid working fluid is gathered in the capillary layer area of ​​the lower shell corresponding to the chip heat transfer area through the capillary action of the capillary layer of the lower shell.

[0034] As an example, Figure 2 is a top view of a heat spreader according to an embodiment of the present invention, referring to Figure 2 A plurality of support columns 60 may be provided in the sealed cavity, and both ends of the plurality of support columns 60 may respectively pass through the capillary layer 50 and be welded to the inner surface of the upper shell 10 and the inner surface of the lower shell 20, and the plurality of support columns 60 may be evenly distributed in the sealed cavity, so that the overall stress strength of the heat spreader is uniform.

[0035] In the embodiment of the present invention, the temperature involved in the reflow soldering process in chip packaging reaches 260°C. When the gas pressure in the sealed cavity of the vapor chamber rises sharply, the support columns evenly distributed between the upper and lower shells can enhance the structural strength of the vapor chamber, ensure that the vapor chamber does not bulge in a high temperature environment, reduce its surface warpage, and improve the yield of chip packaging testing. In addition, the support columns also provide a channel for the reflux of the condensed working fluid, strengthening the two-phase flow heat exchange in the vapor chamber.

[0036] Figure 3 is a cross-sectional view of a vapor chamber according to another embodiment of the present invention. Figure 3 As shown, the heat spreader includes an upper shell 10 and a lower shell 20, the upper shell 10 is groove-shaped, and the lower shell 20 is flat-plate-shaped, the groove of the upper shell 10 and the lower shell 20 form a sealed cavity; the inner surface of the upper shell 10 and the inner surface of the lower shell 20 are respectively provided with a capillary layer 50, and a plurality of support columns 60 are provided in the sealed cavity, and the two ends of the plurality of support columns 60 are respectively connected to the inner surface of the upper shell 10 and the inner surface of the lower shell 20; the plurality of support columns 60 are evenly distributed in the sealed cavity; the lower surface of the lower shell 20 is provided with a base 30.

[0037] As an example, the capillary layer of the upper shell may be free of liquid working fluid and serve as a condensation area of ​​the heat sink.

[0038] In actual applications, when the chip is heated, the liquid working medium in the capillary layer 50 absorbs heat and vaporizes into steam, which can quickly fill the entire sealed cavity. When the gas phase working medium reaches the condensation area of ​​the capillary layer of the upper shell, it will condense, release the heat absorbed during evaporation, condense into liquid phase working medium, and then return to the evaporation area through the support column and the capillary structure thereon, and continue the two-phase flow circulation heat dissipation. Because of the phase change heat transfer involved, the equivalent thermal conductivity of the heat spreader is very high, which can achieve the effect of temperature uniformity in the heat dissipation of the chip, thereby reducing the chip junction temperature.

[0039] As an example, a foot 30 may be provided on the lower surface of the lower housing 20 , and the foot 30 and the lower surface of the lower housing 20 may form a certain space to accommodate components such as chips and capacitors.

[0040] Figure 4 is an appearance diagram of a heat spreader according to an embodiment of the present invention, referring to Figure 4 , the specific structure of the heat spreader in the embodiment of the present invention can be further clearly seen.

[0041] Figure 5 : is a footing design diagram according to an embodiment of the present invention, such as Figure 5 As shown, the base 30 is a continuous frame structure.

[0042] As an example, the base 30 may be a continuous frame structure, so as to protect components such as chips and capacitors placed in the space formed by the base 30 and the lower surface of the lower housing 20 from being damaged by mechanical and thermal stress.

[0043] For example, the base 30 may be square or terrace-shaped, etc. Those skilled in the art may design it according to actual conditions, and the embodiment of the present invention is not limited thereto.

[0044] In an optional embodiment, the base foot 30 and the lower shell 20 are formed integrally or the base foot is welded to the lower shell 20 .

[0045] As an example, the base 30 and the lower shell 20 may be integrally formed, or may be manufactured separately, and then the base 30 and the lower shell 20 may be combined together by welding or the like.

[0046] In an optional embodiment, the processing method of the base 30 and the lower shell 20 includes at least one of the following: brazing, etching, stamping, hot forging, and computer numerical control technology CNC.

[0047] In this embodiment, the base 30 and the lower shell 20 can be processed by brazing, etching, stamping, hot forging and CNC processing methods. The base 30 and the lower shell 20 can be formed as one piece or manufactured separately. The base 30 and the lower shell 20 are then combined together by welding or the like, so that a certain space can be formed between the base and the lower surface of the lower shell 20, thereby accommodating components such as chips and capacitors to protect them from mechanical and thermal stress damage.

[0048] Figure 6 3 is a support column distribution diagram of a vapor chamber according to an embodiment of the present invention. A plurality of support columns 60 are evenly distributed in the sealed cavity, so that the overall stress strength of the vapor chamber is uniform.

[0049] In an optional embodiment, the spacing between the circumferences of the plurality of support pillars 60 is 1 / 8 of the side length of the heat spreader.

[0050] As an example, the spacing between the circumferences of the plurality of support pillars 60 may be 1 / 8 of the side length of the heat spreader, and the number of support pillars may be determined based on the diameter of the support pillars and the side length of the heat spreader. Those skilled in the art may select the diameter of the support pillars based on actual conditions, and the embodiments of the present invention do not limit this.

[0051] In an optional embodiment, the support column 60 is in a cylindrical or truncated cone shape.

[0052] like Figure 6 The figure shows the distribution diagram of the support columns of the heat spreader according to an embodiment of the present invention, wherein the support columns 60 may be cylindrical or truncated cone-shaped.

[0053] It should be noted that the factors affecting the structural strength and heat transfer performance of the support columns are mainly reflected in the parameters such as the diameter of the support columns and the number of support columns. As the diameter of the support columns increases, the structural strength of the heat spreader increases, and the heat transfer performance decreases; as the number of support columns increases, the structural strength of the heat spreader increases, and the heat transfer performance first decreases and then increases. Therefore, the diameter and number of the support columns can be designed by those skilled in the art according to the size or requirements of the actual heat spreader, and the embodiments of the present invention are not limited here.

[0054] In an optional embodiment, the outer surface of the support column 60 is a smooth surface or is provided with a capillary structure.

[0055] As an example, the outer surface of the support column 60 may be a smooth cylinder, or may be surrounded by a capillary layer.

[0056] In this embodiment, the temperature involved in the reflow soldering process in chip packaging can be as high as 260°C. When the gas pressure in the sealed cavity of the heat spreader rises sharply, the support columns between the upper and lower shells can enhance the structural strength of the heat spreader to ensure that the heat spreader does not bulge in a high temperature environment; the support columns are arranged to be evenly distributed so that the overall stress strength of the heat spreader is uniform; in addition, the support columns provide a channel for the reflux of the condensed working fluid, thereby enhancing the two-phase flow heat exchange in the heat spreader.

[0057] In an optional embodiment, the structure of the capillary layer 50 is one of the following: a wire mesh structure, a sintered capillary structure, foam copper, and any combination thereof.

[0058] As an example, the capillary layer 50 can be one of the structures of wire mesh structure, sintered capillary structure, foamed copper, etc. In another example, the capillary layer 50 can also be a combination of two or more of the structures of wire mesh structure, sintered capillary structure, foamed copper, etc.

[0059] As an example, if the outer surface of the support column 60 is surrounded by a capillary layer, the surrounding capillary layer can be one of the structures such as wire mesh structure, sintered capillary structure, foam copper, etc., or it can be a combination structure of two or more of the wire mesh structure, sintered capillary structure, foam copper, etc.

[0060] By using two or more structural combinations for the capillary layer, the heat transfer performance of the heat spreader can be improved, so that the junction temperature of the package containing the heat spreader is lowered compared to the junction temperature of the package containing the copper metal cover, for example, by about 4°C.

[0061] In an optional embodiment, the upper shell 10 or the lower shell 20 is made of copper alloy.

[0062] As an example, the material of the upper shell 10 or the lower shell 20 can be copper alloy, and the shell can be as thick as possible to enhance the structural strength of the heat sink.

[0063] For specific examples in this embodiment, reference may be made to the examples described in the above embodiments and exemplary implementation modes, and this embodiment will not be described in detail herein.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heat sink, characterized in that: It includes an upper shell and a lower shell. The upper shell is groove-shaped, and the lower shell is flat-plate-shaped. The groove of the upper shell and the lower shell form a sealed cavity. The inner surface of the upper shell and the inner surface of the lower shell are respectively provided with capillary layers. A plurality of support columns are provided in the sealed cavity, and the two ends of the plurality of support columns are respectively connected to the inner surface of the upper shell and the inner surface of the lower shell. The plurality of support columns are evenly distributed in the sealed cavity.

2. The vapor chamber according to claim 1, characterized in that: The spacing between the circumferences of the multiple support columns is 1 / 8 of the side length of the heat spreader.

3. The vapor chamber according to claim 1, characterized in that: The support column is in the shape of a cylinder or a truncated cone.

4. The vapor chamber according to claim 1, characterized in that: The outer surface of the support column is a smooth surface or is provided with a capillary structure.

5. The vapor chamber according to claim 1, characterized in that: The lower surface of the lower shell is provided with a foot.

6. The vapor chamber according to claim 5, characterized in that: The base is a continuous frame structure.

7. The vapor chamber according to claim 5, characterized in that: The base foot is integrally formed with the lower shell or the base foot is welded to the lower shell.

8. The vapor chamber according to claim 5, characterized in that: The processing methods of the base and the lower shell include at least one of the following: brazing, etching, stamping, hot forging, and computer numerical control technology CNC.

9. The vapor chamber according to claim 1, characterized in that: The structure of the capillary layer is one of the following: a wire mesh structure, a sintered capillary structure, foam copper, and any combination thereof.

10. The vapor chamber according to claim 1, wherein: The upper shell or the lower shell is made of copper alloy.

11. The vapor chamber according to claim 1, characterized in that: The capillary layer is filled with liquid working medium, and the liquid working medium includes at least one of the following types: water and methanol.

Images