REDUCED CROSS-SECTIONAL STEAM COLUMNS FOR INCREASED AIR FLOW

Abstract

A system is disclosed that comprises an electronic component, a fan arranged to force air in a first direction, a stacked fin array, and a three-dimensional vapor chamber. The three-dimensional vapor chamber includes a base thermally coupled to the electronic component and multiple vapor columns extending outward from the base toward the stacked fin array. A first dimension of a vapor column encompassed by the multiple vapor columns along the first direction is larger than a second dimension of the vapor column along a second direction perpendicular to the first direction.

Description

BACKGROUND of the various embodiments

[0001] Embodiments of the present disclosure generally relate to cooling solutions for computing devices, and more particularly, to cooling solutions including vapor columns with reduced cross-sectional area. Description of related technology

[0002] High-performance electronic components, such as advanced central processing units and graphics processing units, generate relatively large amounts of heat during operation. This heat must be dissipated to prevent the components from overheating and operating at reduced performance levels. Cooling solutions that can effectively remove heat from a system enable electronic components to operate at higher speeds and greater performance levels.

[0003] However, as the energy and power requirements of processing units continue to increase, conventional cooling solutions are limited by many factors, including the thermal transfer properties of the materials and geometries used to construct those cooling solutions. A procedure for cooling electronic

[0004] High-performance components involve placing a heat sink and / or heat pipe in contact with a surface of the electronic component to draw heat away from the component during operation. The heat can then be dissipated by forcing air over or around the heat sink and / or heat pipe using one or more fans. The amount of heat removed from the electronic component can be increased by increasing the fan speed, increasing the fan size, and / or increasing the number of fans forcing air over or around the heat sink and / or heat pipe. However, increasing the fan speed can cause increased acoustic noise, which may be undesirable in consumer products such as PCs, and space constraints may limit the fan size or number of fans that can be used in a given computer system.

[0005] Another approach to cooling high-performance electronic components involves implementing a heatsink assembly that includes a three-dimensional (3D) vapor chamber working in conjunction with a stacked fin array and one or more fans. Fig. Figure 1 illustrates a perspective view of a prior art 3D vapor chamber 100 that can be implemented as part of a conventional heat sink assembly. As shown, the 3D vapor chamber 100 includes a vapor chamber base 105 that contacts the electronic component (e.g., the processing unit) being cooled, and a plurality of cylindrical vapor columns 110 that are attached to the base 105 and extend outwardly therefrom to conduct heat toward and through a stacked fin assembly 115 attached to the 3D vapor chamber 100. As shown in Fig. 2 and Fig. 3, which are top-down views and cross-sectional views of the 3D vapor chamber 100 of Fig. 1, the cylindrical vapor columns 110 extend through the stacked fin assembly 115. One or more fans (not shown) are used to force air over the base 105 of the 3D vapor chamber 100 and through the stacked fin assembly 115, thereby further cooling the electronic component. As shown in Fig. 2, the cylindrical vapor columns 110 are circular, such that the width (e.g., diameter) of a cylindrical vapor column 110 in the x-direction is equal to the length (e.g., diameter) of the cylindrical vapor column 110 in the z-direction.

[0006] Because the cylindrical vapor columns 110 extend outward from the base 105 of the 3D vapor chamber 100, the air forced over the base 105 of the 3D vapor chamber 100 by the one or more fans is impeded by the cylindrical vapor columns 110 and forced to flow around them. That is, each respective cylindrical vapor column 110 included in the 3D vapor chamber 100 impedes the flow of air forced over the base 105, causing the forced air to flow around the cylindrical vapor columns 110 and through channels formed between adjacent cylindrical vapor columns 110. This impedance causes a pressure drop across the base 105 of the 3D vapor chamber 100 in the direction of airflow, which has the effect of reducing the amount of heat that the forced air can dissipate and remove from the electronic component.Although increasing the fan speed, increasing the size of the fans, and / or increasing the number of fans to force more air over the heat sink assembly would improve overall heat dissipation and cooling, as described above, these approaches may increase acoustic noise in an undesirable manner or may not be effectively implemented due to space constraints in a given computer system.

[0007] As the foregoing illustrates, more effective techniques for removing heat from electronic components during operation are needed in the art. SUMMARY

[0008] One embodiment of the present disclosure sets forth a system comprising an electronic component, a fan arranged to force air in a first direction, a stacked fin assembly, and a three-dimensional vapor chamber. The three-dimensional vapor chamber includes a base thermally coupled to the electronic component and a plurality of vapor columns extending outwardly from the base toward the stacked fin assembly. A first dimension of a first vapor column included in the plurality of vapor columns along the first direction is greater than a second dimension of the first vapor column along a second direction perpendicular to the first direction.

[0009] At least one technical advantage of the disclosed embodiment relative to the prior art is that, in the disclosed embodiment, the pressure drop across a 3D vapor chamber within a cooling system can be reduced without increasing the fan speed, fan size, or the number of fans forcing air through the vapor chamber. In this regard, the vapor columns included in the disclosed embodiment are configured such that the cross-sectional area of ​​each vapor column is reduced in a direction perpendicular to airflow across the base of the 3D vapor chamber. By reducing the cross-sectional area of ​​each vapor column in the direction of airflow across the 3D vapor chamber base, the overall impedance created by the vapor columns and experienced by the 3D vapor chamber is reduced relative to prior art embodiments.The reduction in impedance results in a reduced pressure drop across the 3D vapor chamber relative to pressure drops experienced in prior art designs. Thus, with the disclosed design, the amount of heat that can be dissipated by the cooling system can be increased without increasing the fan speed, fan size, or the number of fans implemented as part of the cooling system. These technical advantages provide one or more technological improvements over prior art approaches. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the above-recited features of the various embodiments may be understood in detail, a more specific description of the inventive concepts briefly summarized above may be given by reference to various embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate merely typical embodiments of this invention and are therefore not to be considered as limiting its scope in any way, and that other equally effective embodiments may exist. Fig. 1 illustrates a perspective view of a prior art three-dimensional (3D) vapor chamber implemented in a conventional cooling system; Fig. Figure 2 illustrates a top-down view of the 3D steam chamber of Fig. 1; Fig. Figure 3 illustrates a cross-sectional view of the 3D vapor chamber of Fig. 1; Fig. 4 illustrates a perspective view of a cooling system according to various embodiments; Fig. Figure 5 illustrates a perspective view of the cooling system of Fig. 4 according to various embodiments; Fig. Figure 6 illustrates a cross-sectional view of a 3D vapor chamber used in the cooling system of Fig. 4 is implemented according to various embodiments; Fig. Figure 7 illustrates a thermal resistance circuit for the cooling system of Fig. 4 according to various embodiments; Fig. Figure 8 illustrates a top-down view of the 3D steam chamber of Fig. 6 according to various embodiments; Fig. Figure 9 illustrates a perspective view of a portion of the 3D vapor chamber of Fig. 6 according to various embodiments; Fig. 10A-10C illustrate top views of different exemplary vapor column cross-sections according to various embodiments; and Fig. 11 illustrates exemplary pressure drop versus flow rate curves for different cooling systems according to various embodiments. DETAILED DESCRIPTION

[0011] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the various embodiments. However, it will be understood by one skilled in the art that the inventive concepts may be practiced without one or more of these specific details.

[0012] Fig. 4 illustrates a perspective view of a cooling system 400 according to various embodiments. The cooling system 400 is described herein as being used to cool an electronic component, such as a processing unit or other type of electronic component and / or device that generates heat during operation and needs to be cooled. In some examples, the cooling system 400 may be implemented in a computer system to cool one or more electronic components included in the computer system. As will be apparent to those skilled in the art, a computer system including and / or implementing the cooling system 400 may be any type of technically feasible computer system, including, without limitation, a server machine, a server platform, a desktop machine, a laptop machine, a handheld / mobile device, or a portable device.Additionally, when implemented and / or included in a computer system, the cooling system 400 may be used to cool one or more electronic components, such as a central processing unit (CPU), a graphics processing unit (GPU), a parallel processing unit, a switching device, a memory unit, a storage unit, and / or some other electronic component or device included in the computer system. Furthermore, those skilled in the art will understand that the cooling system 400 may also be used to cool other types of components or objects that generate heat during operation. For example, the cooling system 400 may be implemented in and / or otherwise used to cool components other than electronic components included in computer systems and / or computing devices.

[0013] As in Fig. 4, the cooling system 400 includes a fan 405, a stacked fin assembly 410, and a three-dimensional (3D) vapor chamber 600. The stacked fin assembly 410 is a type of heat sink that includes a plurality of thermally conductive plates or fins spaced apart by air gaps. The 3D vapor chamber 600 includes a vapor chamber base 415 that contacts the electronic component 605 being cooled and a plurality of vapor columns 420 attached to and extending outward from the vapor chamber base 415. As shown, the plurality of vapor columns 420 extend through respective openings formed in the stacked fin assembly 410, which is separate from and attached to the 3D vapor chamber 600. When attached to the 3D vapor chamber 600, the stacked fin assembly 410 is in thermal contact with the plurality of vapor columns 420.In some cases, the stacked fin assembly 410 and the 3D vapor chamber 600 may collectively be referred to as a heatsink assembly.

[0014] As in Fig. 5, which illustrates a perspective view of the cooling system 400 with the fan 405 removed, a fan mount 500 is used to attach the fan 405 to the stacked fin assembly 410. However, those skilled in the art will understand that in some embodiments, the fan 405 is attached to the cooling system 400 in a different arrangement. Furthermore, although the cooling system 400 is shown with a single fan 405, in some embodiments the cooling system 400 includes more than one fan. For example, in some embodiments, the cooling system 400 includes two or more fans. In some embodiments, the cooling system 400 does not include a fan 405 directly attached to the stacked fin assembly 410. In such embodiments, the cooling system 400 includes one or more external fans and / or air movers external to the stacked fin assembly 410.Furthermore, in such embodiments, the stacked fin assembly 410 and / or the 3D vapor chamber 600 are positioned in the path of the air forced by the one or more external fans and / or air movers.

[0015] In operation, the stacked fin assembly 410 and the 3D vapor chamber 600 work to dissipate heat away from the electronic component 605 being cooled. Furthermore, the fan 405 forces air over the vapor chamber base 415 to further remove heat from the electronic component 605 via convection. With reference to the Fig. 4-6 and Fig. 8-9, the direction in which the fan 405 forces air across the vapor chamber base 415 is the z-direction. As described in more detail below, air forced in the z-direction by the fan 405 flows between the fins included in the stacked fin assembly 410 and around the vapor columns 420 extending through the stacked fin assembly 410.

[0016] Fig. 6 illustrates a cross-sectional view of the 3D vapor chamber 600 included in the cooling system 400 according to various embodiments. For illustrative purposes, the stacked fin assembly 410 attached to the 3D vapor chamber 600 is also illustrated in the cross-sectional view of the 3D vapor chamber 600. With reference to the coordinate axes 425, the cross-sectional view of the 3D vapor chamber 600 is taken along the xy plane and is perpendicular to the z direction in which the fan 405 forces air over the vapor chamber base 415. As shown, the vapor chamber base 415 includes a bottom surface 610 and a top surface 615. The bottom surface 610 of the vapor chamber base 415 is arranged to contact the electronic component 605 being cooled by the cooling system 400.

[0017] The vapor columns 420 are attached to and extend outward from the upper surface 615 of the vapor chamber base 415, such that the respective interiors of the vapor columns 420 are open within the interior of the vapor chamber base 415. This combined interior of the vapor chamber base 415 and the vapor columns 420 may be referred to as the vapor space 620 of the 3D vapor chamber 600. A wicking material 625 is disposed between the vapor space 620 and the enclosure 630 of the 3D vapor chamber 600. The enclosure 630 of the 3D vapor chamber 600, which may be formed from a thermally conductive material such as copper, forms the exterior of the vapor chamber base 415 and the vapor columns 420. The wick material 625 lining the inner surface of the enclosure 630 may be implemented as one or more of a sintered wick, a grooved wick, a braided / bundled fiber wick, or another type of wick.

[0018] During operation of the cooling system 400, heat dissipated from the electronic component 605 is input or introduced into the 3D vapor chamber 600 via conduction through the bottom surface 610 of the vapor chamber base 415. This introduction of heat into the 3D vapor chamber 600 causes a liquid entrained by the wicking material 625 to vaporize and spread throughout the vapor space 620 away from the electronic component 605. As the vapor spreads throughout the vapor space 620, for example, throughout the interior of the vapor chamber base 415 and / or the interior of the vapor columns 420, the vapor condenses on the fins of the stacked fin assembly 410. Heat is then removed from the condensate formed on the fins of the stacked fin assembly 410 by the fan 405, which forces air over the vapor chamber base 415 and through the stacked fin assembly 410 in the z-direction.Capillary forces in the wick material 625 then return the condensate formed on the fins of the stacked fin assembly 410 and the cooling process is repeated.

[0019] As described above, air forced over the vapor chamber base 415 and through the stacked fin assembly 410 by the fan 405 helps remove heat from the stacked fin assembly 410. However, as the forced air flows through the stacked fin assembly 410, the airflow is obstructed by the vapor columns 420 that protrude through the stacked fin assembly 410. For example, with respect to the coordinate axes 425, the vapor columns 420 extend in the x- and y-directions, thereby blocking the airflow forced by the fan 405 in the z-direction, which is perpendicular to the x- and y-directions. The dimension of a vapor column 420 extending in the x-direction (e.g., along the x-axis) may be referred to as the width of the vapor column 420, and the dimension of a vapor column 420 extending in the y-direction (e.g., along the y-axis) may be referred to as the height of the vapor column 420.

[0020] When air forced across the vapor chamber base 415 in the z-direction by the fan 405 is obstructed by a vapor column 420, the air is redirected to flow through flow passages 635 formed between adjacent vapor columns 420. However, as described above with respect to the prior art 3D vapor chamber 100, when the vapor columns 420 obstruct the flow of air in the z-direction, such that the air is forced to flow through flow passages 635 formed between adjacent vapor columns 420, a drop in air pressure across the vapor chamber base 415 in the z-direction occurs. As the drop in air pressure across the vapor chamber base 415 increases, the amount of heat that can be dissipated via convection by the air forced by the fan 405 decreases.

[0021] Although increasing the speed of fan 405, increasing the size of fan 405, and / or increasing the number of fans 405 to force more air across the heat sink assembly would improve overall heat dissipation and cooling, as described above, these approaches may increase acoustic noise in an undesirable manner or may not be effectively implemented due to space constraints in a given computer system. Accordingly, to increase the amount of heat that can be dissipated by cooling system 400 via convection, 3D vapor chamber 600 is configured to reduce the drop in air pressure across vapor chamber base 415 in the z-direction.

[0022] The drop in air pressure across the vapor chamber base 415 in the z-direction can be determined using the Darcy-Weisbach equation, expressed below as Equation 1. ΔP=fLv2ρ2DH

[0023] Where ΔP is the drop in air pressure across the vapor chamber base 415 in the z-direction, f is the airflow coefficient, L is the length of the flow passage 635 through which air is forced, v is the velocity of airflow through the flow passage 635, ρ is the density of air, and D H is the hydraulic diameter of the flow passage 635. With reference to the coordinate axes 425, the hydraulic diameter (e.g., width) of a flow passage 635 formed between adjacent steam columns 420 is equal to the distance in the x-direction (e.g., along the x-axis) between the adjacent steam columns 420.

[0024] As expressed above in Equation 1, the drop in air pressure across the vapor chamber base 415 in the z-direction is inversely proportional to the hydraulic diameter of a flow passage 635 formed between adjacent vapor columns 420. Accordingly, the drop in air pressure across the vapor chamber base 415 in the z-direction can be reduced by increasing the hydraulic diameter of the flow passages 635 formed between adjacent vapor columns 420. A similar conclusion regarding this relationship between the hydraulic diameter of a flow passage 635 and a reduction in the air pressure drop across the vapor chamber base 415 can be reached when the cooling system 400 is modeled as a thermal resistance circuit.

[0025] Fig. Figure 7 illustrates a thermal resistance circuit 700 for the cooling system 400. As shown, the thermal resistance circuit 700 includes the equivalent thermal resistances of the components included in the cooling system 400. For example, the thermal resistance circuit 700 includes the equivalent thermal resistance R silicon-b the base or bottom of the electronic component 605 (e.g. a silicon chip) being cooled, the equivalent thermal resistance R silicon-c of the housing or the upper part of the electronic component 605 being cooled, the equivalent thermal resistance R TIM the thermal interface between the electronic component 605 being cooled and the 3D vapor chamber 600, the equivalent thermal resistance R VC the 3D steam chamber 600, the equivalent thermal resistance R HS the stacked fin arrangement 410 and the equivalent thermal resistance R convectivethe air forced over the vapor chamber base 415 by the fan 405 to remove heat from the stacked fin assembly 410.

[0026] In addition, the thermal resistance circuit 700 indicates the respective temperatures of components included in the cooling system 400. For example, the temperature T b the temperature of the bottom of the electronic component 605 being cooled, the input temperature T j the thermal resistance circuit 700 outputs the temperature of the electronic component 605 being cooled, the temperature T c indicates the temperature of the top of the electronic component 605 which is cooled, the temperature T TIM indicates the temperature of the thermal interface between the silicon coating of the electronic component 605 being cooled and the 3D vapor chamber 600, the temperature T VC indicates the temperature of the 3D steam chamber 600, the temperature THS indicates the temperature of the stacked fin arrangement 410 and the output temperature T ∞ indicates the initial temperature of the air forced over the vapor chamber base 415 and through the stacked fin assembly 410 by the fan 405 to remove heat from the stacked fin assembly 410.

[0027] The amount of heat that air forced over the vapor chamber base 415 removes from the stacked fin assembly 410 via convection can be determined using Equation 2 below. QConvective=THS−T∞RConvective

[0028] Where Q Convective is the amount of heat removed from the stacked fin assembly 410 by air forced over the vapor chamber base 415 in the z-direction by the fan 405, R convective is the equivalent thermal resistance of the air forced across the vapor chamber base 415 in the z-direction by the fan 405, T HSthe temperature of the stacked fin arrangement 410 and T ∞ is the temperature of the air forced across the vapor chamber base 415 in the z-direction by the fan 405.

[0029] As expressed below by equation 3, the equivalent thermal resistance R convective of air forced across the vapor chamber base 415 in the z-direction by the fan 405 is inversely proportional to the mass flow rate of air forced across the vapor chamber base 415 in the z-direction by the fan 405. RConvective=1mCp

[0030] Where m is the mass flow rate of air forced across the vapor chamber base 415 in the z-direction by the fan 405 and C pis the specific heat capacity of air. Using Equation 4 below, the mass flow rate of air forced across the vapor chamber base 415 in the z-direction by the fan 405 can be expressed as a function of the velocity of the forced air as it flows through a flow passage 635 formed between adjacent vapor columns 420, the cross-sectional area of ​​the flow passage 635, and the density of air. m=ρvA

[0031] Where m is the mass flow rate of air flowing through a flow passage 635, ρ is the density of air, v is the velocity of air flowing through the flow passage 635, and A is the cross-sectional area of ​​the flow passage 635.

[0032] When Equations 2-4 are combined into Equation 5, expressed below, it becomes apparent that the amount of heat removed from the stacked fin assembly 410 by air forced across the vapor chamber base 415 in the z-direction by the fan 405 is proportional to the cross-sectional area of ​​the flow passage 635. That is, the amount of heat removed from the stacked fin assembly 410 by the air forced across the vapor chamber base 415 in the z-direction by the fan 405 increases as the cross-sectional area of ​​the flow passage 635 increases. QConvective=ρvACp(THS−T∞)

[0033] Where Q Convectiveis the amount of heat removed from the stacked fin assembly 410 by the air forced over the vapor chamber base 415 in the z-direction by the fan 405, ρ is the density of air, v is the velocity of air flowing through the flow passage 635, and A is the cross-sectional area of ​​the flow passage 635, C p is the specific heat capacity of air, T HS is the temperature of the stacked fin assembly 410 and T ∞ is the temperature of the air forced across the vapor chamber base 415 in the z-direction by the fan 405.

[0034] As described above with reference to Equations 1-5, increasing the hydraulic diameter of a flow passage 635 formed between adjacent steam columns 420 and / or the cross-sectional area of ​​a flow passage 635 formed between adjacent steam columns 420 reduces the drop in air pressure across the steam chamber base 415 in the z-direction and increases the amount of heat removed from the stacked fin assembly 410 by air forced across the steam chamber base 415 in the z-direction by the fan 405. Since the hydraulic diameter of a flow passage 635 formed between adjacent steam columns 420 is equal to the distance in the x-direction between the adjacent steam columns 420, the hydraulic diameter of a flow passage 635 formed between adjacent steam columns 420 is inversely proportional to the respective widths of the adjacent steam columns 420.For example, if the respective widths of adjacent steam columns 420 are increased (e.g., the steam columns 420 extend in the x-direction), the hydraulic diameter of the flow passage 635 formed between the adjacent steam columns 420 decreases. Conversely, if the respective widths of the adjacent steam columns 420 are decreased (e.g., the steam columns 420 are reduced in size in the x-direction), the hydraulic diameter of the flow passage 635 formed between the adjacent steam columns 420 increases. Therefore, the hydraulic diameter of a flow passage 635 formed between adjacent steam columns 420 can be increased by decreasing the widths of the adjacent steam columns 420. In some embodiments, the hydraulic diameter of a flow passage 635 formed between adjacent steam columns 420 is configured to be larger than the respective widths of the adjacent steam columns 420.

[0035] However, simply reducing the width of a vapor column 420 may cause the performance level of the vapor column 420 to decrease if the volume of the vapor space 620 and / or the wicking material 625 within the vapor column 420 is also reduced. For example, if the volume of the vapor space 620 within an interior of a vapor column 420 and / or an amount of wicking material 625 in a vapor column 420 is reduced, the vapor column 420 becomes less efficient at dissipating heat away from the electronic component 605. Thus, to prevent a decrease in performance caused by reducing the internal volume of a vapor column 420, the vapor columns 420 included in the 3D vapor chamber 600 are configured such that a width of a vapor column 420 is reduced while the length of the vapor column 420 is increased.In some embodiments, the length of each vapor column 420 included in the 3D vapor chamber 600 is greater than the width of each vapor column 420 included in the 3D vapor chamber 600. In some embodiments, only some of the vapor columns 420 included in the 3D vapor chamber 600 have lengths that are greater than their widths.

[0036] Fig. Figure 8 illustrates a top-down view of the 3D vapor chamber 600 with the stacked fin assembly 410 removed, according to various embodiments. With reference to the coordinate axes 425, the length of a vapor column 420 is the dimension of the vapor column extending in the z-direction (e.g., along the z-axis). As shown in Fig. 8, the length of each vapor column 420 is greater than the width of each vapor column 420. In the illustrated example of Fig. 8, the length of each vapor column 420 is approximately 10.66 mm and the width of each vapor column 420 is approximately 4 mm. Accordingly, the length of each vapor column 420 is approximately 265% greater than the width of each vapor column 420. Those skilled in the art will understand that a length of 10.66 mm and a width of 4 mm are merely two non-limiting examples of the dimensions of a vapor column 420. Furthermore, those skilled in the art will understand that the vapor columns 420 can be configured with length-to-width ratios other than the length-to-width ratio shown in the example of Fig. 8 is illustrated.

[0037] In some embodiments, the length of a vapor column 420 is more than 265% greater than the width of the vapor column 420. For example, in some embodiments, the length of a vapor column 420 is 300% greater, 350% greater, 400% greater, or another percentage amount greater than the width of the vapor column 420. In some embodiments, the percentage amount by which the length of a vapor column 420 is greater than the width of the vapor column 420 is less than 265%. For example, in some embodiments, the length of a vapor column 420 is 250% greater, 200% greater, 150% greater, or another percentage amount greater than the width of the vapor column 420. In some embodiments, the length of the vapor column 420 is configured to be at least a minimum percentage amount (e.g., 100%, 150%, 200%, etc.) greater than the width of the vapor column 420.

[0038] Since the length of a vapor column 420 is the dimension of the vapor column 420 that extends in the z-direction (e.g., along the z-axis), the length of the vapor column 420 is the dimension of the vapor column 420 that is parallel to the direction (e.g., the z-direction) in which the fan 405 forces air across the vapor chamber base 415 to cool the stacked fin assembly 410. Therefore, increasing the length of a vapor column 420 in the z-direction does not impede the flow of forced air as it flows through a flow passage 635. Accordingly, by reducing the width of the steam columns 420 in the x-direction and increasing the lengths of the steam columns 420 in the z-direction, the 3D steam chamber 600 experiences the above-described benefits of flow passages 635 with increased hydraulic diameters without negatively impacting the heat dissipation capabilities of the steam columns 420.

[0039] Fig. Figure 9 illustrates a perspective view of a portion of the 3D vapor chamber 600 with the stacked fin assembly 410 removed, according to various embodiments. Fig. 9, an outline of a flow passage 635 and first and second cross-sectional areas 900, 905 of the vapor columns 420 are illustrated. Although the first cross-sectional area 900 is illustrated with reference to only one of the vapor columns 420, those skilled in the art will understand that the description of the first cross-sectional area 900 applies equally to the other Fig. 9. Similarly, although the second cross-sectional area 905 is illustrated with reference to only one of the vapor columns 420, those skilled in the art will understand that the description of the second cross-sectional area 905 applies equally to the other vapor columns 420 shown in Fig. 9 illustrated steam columns 420 is applicable.

[0040] With reference to the coordinate axes 425, the first cross-sectional area 900 is parallel to the yz plane. Accordingly, the first cross-sectional area 900 is parallel to the direction (e.g., the z direction) in which the fan 405 forces air over the vapor chamber base 415. Furthermore, the first cross-sectional area 900 is representative of a size of the portion of the vapor column 420 that does not impede the airflow forced over the vapor chamber base 415 by the fan 405. The value of the first cross-sectional area 900 is equal to the product of the length of the vapor column 420 and the height of the vapor column 420. The second cross-sectional area 905 is parallel to the xy plane. Accordingly, the second cross-sectional area 905 is perpendicular to the direction (e.g., the z direction) in which the fan 405 forces air over the vapor chamber base 415.Thus, the second cross-sectional area 905 is representative of the portion of the vapor column 420 that obstructs the flow of air forced over the vapor chamber base 415 by the fan 405. The value of the second cross-sectional area 905 is equal to the product of the width of the vapor column 420 and the height of the vapor column 420.

[0041] Since the length of a vapor column 420 is greater than the width of the vapor column 420, the value of the first cross-sectional area 900 of a vapor column 420 is greater than the value of the second cross-sectional area 905 of the vapor column 420. Therefore, the cross-sectional area of ​​the vapor column 420 that is parallel to the direction in which the fan 405 forces air over the vapor chamber base 415 is greater than the cross-sectional area of ​​the vapor column that is perpendicular to the direction in which the fan 405 forces air over the vapor chamber 415. In other words, the cross-sectional area of ​​the vapor column 420 that obstructs the flow of air forced across the vapor chamber base 415 by the fan 405 (e.g., the second cross-sectional area 905) is reduced relative to the cross-sectional area of ​​the vapor column 420 that does not obstruct the flow of air forced across the vapor chamber base 415 by the fan 405 (e.g., the first cross-sectional area 900).

[0042] The steam columns 420 are in Fig. 6, Fig. 8 and Fig. 9, have a generally flattened, rectangular shape. For example, the vapor columns 420 are shaped like rectangular prisms with rounded edge surfaces. Fig. 10A illustrates a top-down view of a cross-section of a vapor column 420A implemented as a rectangular prism with rounded or curved edge surfaces. As shown, the cross-section of the vapor column 420A is generally rectangular in shape, and thus, the base of the vapor column 420A is generally rectangular in shape. The edge surfaces 1005A, 1005B of the vapor column 420A that extend in the x-direction have a convex curvature relative to the interior of the vapor column 420A. Curving the edge surfaces 1005A, 1005B in this manner improves the aerodynamic performance of the vapor column 420A, so that when air is forced over the vapor chamber base 415 in the z-direction by the fan 405, the curved edge surface 1005A would impede air flowing in the z-direction less than a straight or flat edge surface. As further shown in Fig. 10A, the edge surfaces 1010A, 1010B of the vapor column 420A, which are generally parallel to the z-direction in which air is forced over the vapor chamber base 415, are flattened and / or straight.

[0043] Fig. 10B illustrates a top-down view of a cross-section of a vapor column 420B that is generally teardrop-shaped. The base of the vapor column 420B has a teardrop shape such that a first edge surface 1015 of the vapor column 420B extending in the x-direction has a convex curvature facing the direction in which the fan 405 forces airflow over the vapor chamber base 415. The vapor column 420B further includes edge surfaces 1020A, 1020B extending in the z-direction and joining at an apex 1025. As shown, the length of the teardrop-shaped vapor column 420B is greater than the width of the teardrop-shaped vapor column 420B. Compared to other shapes that may be used to implement a vapor column 420, the teardrop shape of the vapor column 420B is less resistive to air flow in the z-direction. Fig. 10C illustrates a top-down cross-sectional view of a vapor column 420C that is generally oval-shaped. That is, the base of the vapor column 420C has an oval shape. As shown, the length of the oval-shaped vapor column 420C is greater than the width of the oval-shaped vapor column 420C.

[0044] Experts will understand that the Fig. 10A-10C are merely some non-limiting examples of shapes that may be used to implement a vapor column 420 included in the 3D vapor chamber 600. Furthermore, those skilled in the art will understand that any feasible shape for which the length of a vapor column 420 is greater than the width of the vapor column 420 may be used to implement the vapor columns 420 included in the 3D vapor chamber 600. For example, in some embodiments where the vapor column 420 has a generally rectangular shape (e.g., vapor column 420A), the edge surfaces 1005A, 1005B of the vapor column 420A are flattened so that the base of the vapor column 420A is a rectangle with straight edges. As another example, in some embodiments, the edge surfaces 1010A, 1010B of the vapor column 420A are curved.

[0045] Fig. 11 illustrates a graph 1100 comprising exemplary pressure drop versus flow rate curves for different cooling systems. A first curve 1105 included in the graph 1100 is associated with the performance of a cooling system incorporating the prior art 3D vapor chamber 100. In particular, the first curve 1105 indicates the amount by which the air pressure drops across the base 105 of the prior art 3D vapor chamber 100 and through the stacked fin assembly 115 attached to the prior art 3D vapor chamber 100 in the direction in which a fan included in the cooling system forces air across the base 105 and through the stacked fin assembly 115. As described above, the vapor columns 110 included in the prior art 3D vapor chamber 100 have a cylindrical shape in which the width of a vapor column 110 and the length of the vapor column 110 are both equal to the diameter of the vapor column 110.In the case of . Fig. In the example illustrated in Figure 11, each cylindrical vapor column 110 in which the prior art 3D vapor chamber 100 was implemented had a diameter of 8 mm when the cooling system was operated to obtain the pressure drop versus flow rate performance indicated by the first curve 1105.

[0046] A second curve 1110 included in the graph 1100 is associated with the performance of the cooling system 400 including the 3D vapor chamber 600 described herein. In particular, the second curve 1110 indicates the amount by which the air pressure across the vapor chamber base 415 and the stacked fin assembly 410 drops in the direction (e.g., the z-direction) in which the fan 405 forces air across the vapor chamber base 415 and through the stacked fin assembly 410. As described above, the respective lengths of the vapor columns 420 included in the 3D vapor chamber 600 are greater than the respective widths of the vapor columns 420. In the illustrated example of Fig.11, each vapor column 420 implemented in the 3D vapor chamber 600 had a generally rectangular shape, such as the shape of vapor column 420A, when the cooling system 400 was operated to obtain the pressure drop versus flow rate performance indicated by the second curve 1110. Furthermore, each vapor column 420 implemented in the 3D vapor chamber 600 had a length of 10.66 mm and a width of 4 mm when the cooling system 400 was operated to obtain the pressure drop versus flow rate performance indicated by the second curve 1110. Thus, compared to the cross-sectional area in the direction of airflow of a cylindrical vapor column 110 with a diameter of 8 mm, the cross-sectional area in the direction of airflow of the 4 mm wide rectangular vapor column 420 is approximately 50% smaller.

[0047] As indicated by the first curve 1105, the amount by which the air pressure across the base 105 of the prior art 3D vapor chamber 100 and the stacked fin assembly 115 drops increases as the speed of the fan blowing air across the base 105 of the prior art 3D vapor chamber 100 and through the stacked fin assembly 115 increases. Similarly, as indicated by the second curve 1110, the amount by which the air pressure across the vapor chamber base 415 and the stacked fin assembly 410 drops in the z-direction increases as the speed of the fan 405 blowing air across the vapor chamber base 415 and through the stacked fin assembly 410 in the z-direction increases.However, when comparing the first curve 1105 with the second curve 1110, it can be seen that the air pressure drop across the 3D vapor chamber 600, which includes the flattened, generally rectangular-shaped vapor columns 420, and the stacked fin array 410, is less than the air pressure drop across the prior art 3D vapor chamber 100, which includes the cylindrical vapor columns 110 and the stacked fin array 115. As described above, the amount of air pressure drop across a particular 3D vapor chamber base is inversely proportional to the amount of heat that can be dissipated by a particular cooling system via convection.Therefore, as indicated by first and second curves 1105, 1110, decreasing the cross-sectional area of ​​each vapor column 420 in the direction of airflow over the vapor chamber base 415 allows the cooling system 400 to dissipate more heat via convection than a cooling system incorporating the prior art 3D vapor chamber 100.

[0048] In summary, a cooling system that cools an electronic component, such as a processing unit. The cooling system also includes a stacked fin array and a three-dimensional vapor chamber. The three-dimensional vapor chamber includes a base thermally coupled to an electronic component and a plurality of vapor columns extending outward from the base toward the stacked fin array. The cooling system further includes a fan arranged to force air in a first direction across the base of the three-dimensional vapor chamber. A first vapor column included in the plurality of vapor columns has a first dimension parallel to the first direction in which the fan forces air across the base of the three-dimensional vapor chamber.The first dimension of the first vapor column is also greater than a second dimension of the first vapor column along a second direction that is perpendicular to the first direction in which the fan forces air over the base of the three-dimensional vapor chamber.

[0049] At least one technical advantage of the disclosed embodiment relative to the prior art is that, in the disclosed embodiment, the pressure drop across a 3D vapor chamber within a cooling system can be reduced without increasing the fan speed, fan size, or the number of fans forcing air through the vapor chamber. In this regard, the vapor columns included in the disclosed embodiment are configured such that the cross-sectional area of ​​each vapor column is reduced in a direction perpendicular to airflow across the base of the 3D vapor chamber. By reducing the cross-sectional area of ​​each vapor column in the direction of airflow across the 3D vapor chamber base, the overall impedance created by the vapor columns and experienced by air flowing through the 3D vapor chamber is reduced relative to prior art embodiments.The reduction in impedance results in a reduced pressure drop across the 3D vapor chamber relative to pressure drops experienced in prior art designs. Thus, with the disclosed design, the amount of heat that can be dissipated by the cooling system can be increased without increasing the fan speed, fan size, or the number of fans implemented as part of the cooling system. 1. According to some embodiments, a system comprises an electronic component; a fan arranged to force air in a first direction; a stacked fin assembly; and a three-dimensional vapor chamber having a base thermally coupled to the electronic component; and a plurality of vapor columns extending outwardly from the base toward the stacked fin assembly, wherein a first dimension of a first vapor column included in the plurality of vapor columns along the first direction is greater than a second dimension of the first vapor column along a second direction perpendicular to the first direction. 2. The system according to clause 1, wherein a first cross-sectional area of ​​the first vapor column is parallel to the first direction and greater than a second cross-sectional area of ​​the first vapor column that is perpendicular to the first direction. 3. The system according to clause 1 or 2, wherein a first surface of the first vapor column perpendicular to the first direction has a convex curvature. 4. The system according to any one of clauses 1-3, wherein the first vapor column comprises a rectangular prism. 5. The system according to any one of clauses 1-4, wherein a base of the first vapor column has an oval shape. 6. The system according to any one of clauses 1-5, wherein a base of the first vapor column has a teardrop shape. 7. The system according to any one of clauses 1-6, wherein a second vapor column included in the plurality of vapor columns is disposed adjacent to the first vapor column, and air forced in the first direction by the fan flows through a passage defined between the first vapor column and the second vapor column. 8. The system according to any one of clauses 1-7, wherein a hydraulic diameter of the passage is inversely proportional to the second dimension of the first vapor column. 9. The system according to any of clauses 1-8, wherein the fan forces air in the first direction across the base of the three-dimensional vapor chamber. 10. According to some embodiments, a heat sink assembly comprises a stacked fin assembly; and a three-dimensional vapor chamber comprising a base having a bottom surface and a top surface, a plurality of vapor columns extending outwardly from the top surface of the base toward the stacked fin assembly, wherein a first cross-sectional area of ​​a first vapor column of the plurality of vapor columns is greater than a second cross-sectional area of ​​the first vapor column, and a vapor space defined within the base and the plurality of vapor columns. 11. The heat sink assembly of clause 10, wherein the first cross-sectional area is perpendicular to the second cross-sectional area. 12. The heat sink assembly according to clause 10 or 11, wherein a second vapor column included in the plurality of vapor columns is disposed adjacent to the first vapor column; and wherein a passage is defined between the first vapor column and the second vapor column. 13. The heat sink assembly according to any one of clauses 10-12, wherein a hydraulic diameter of the passage is inversely proportional to the second cross-sectional area of ​​the first vapor column. 14. The heat sink assembly according to any one of clauses 10-13, wherein a hydraulic diameter of the passage is greater than a dimension of the first vapor column. 15. The heat sink assembly of any one of clauses 10-14, wherein the dimension of the first vapor column is perpendicular to the first cross-sectional area. 16. The heat sink assembly of any one of clauses 10-14, wherein a base of the first vapor column has a teardrop shape. 17. According to some embodiments, a three-dimensional vapor chamber comprises a base having a bottom surface and a top surface; a plurality of vapor columns extending outwardly from the top surface of the base toward the stacked fin assembly, wherein a first cross-sectional area of ​​a first vapor column of the plurality of vapor columns is greater than a second cross-sectional area of ​​the first vapor column; and a vapor space defined within the base and the plurality of vapor columns. 18. The three-dimensional vapor chamber according to clause 17, wherein the first cross-sectional area is perpendicular to the second cross-sectional area. 19. The three-dimensional vapor chamber according to clause 17 or 18, wherein a first surface of the first vapor column has a convex curvature and a second surface of the first vapor column is flat; 20. The three-dimensional vapor chamber according to any one of clauses 17-19, wherein the first surface of the first vapor column extends in a first direction and the second surface of the first vapor column extends in a second direction perpendicular to the first direction.

[0050] Any and all combinations of any of the claim elements recited in any of the claims and / or any elements described in this application are in any way within the contemplated scope of the present invention and protection.

[0051] The descriptions of the various embodiments have been presented for illustrative purposes, but are not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

[0052] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be made without departing from the basic scope thereof, and the scope thereof is determined by means of the following claims.

Claims

[1] System comprising: an electronic component; a fan arranged to force air in a first direction; a stacked fin arrangement; and a three-dimensional steam chamber that includes: a base thermally coupled to the electronic component; and a plurality of vapor columns extending outwardly from the base toward the stacked fin assembly, wherein a first dimension of a first vapor column included in the plurality of vapor columns along the first direction is greater than a second dimension of the first vapor column along a second direction perpendicular to the first direction. [2] The system of claim 1, wherein a first cross-sectional area of the first vapor column is parallel to the first direction and larger than a second cross-sectional area of the first vapor column that is perpendicular to the first direction. [3] The system of claim 1 or 2, wherein a first surface of the first vapor column perpendicular to the first direction has a convex curvature. [4] A system according to any preceding claim, wherein the first vapor column comprises a rectangular prism. [5] A system according to any preceding claim, wherein a base of the first vapor column has an oval shape or has a teardrop shape. [6] A system according to any preceding claim, wherein a second steam column included in the plurality of steam columns is arranged adjacent to the first steam column, and air forced in the first direction by the fan flows through a passage defined between the first steam column and the second steam column, and a hydraulic diameter of the passage is preferably inversely proportional to the second dimension of the first steam column. [7] A system according to any preceding claim, wherein the fan forces air in the first direction across the base of the three-dimensional vapor chamber. [8] Heat sink assembly comprising: a stacked fin arrangement; and a three-dimensional steam chamber that includes: a base comprising a lower surface and a top surface; a plurality of vapor columns extending outwardly from the upper surface of the base toward the stacked fin assembly, wherein a first cross-sectional area of a first vapor column of the plurality of vapor columns is greater than a second cross-sectional area of the first vapor column; and a vapor space defined within the base and the plurality of vapor columns. [9] The heat sink assembly of claim 8, wherein the first cross-sectional area is perpendicular to the second cross-sectional area. [10] The heat sink assembly according to claim 8 or 9, wherein a second vapor column included in the plurality of vapor columns is disposed adjacent to the first vapor column; and wherein a passage is defined between the first vapor column and the second vapor column. [11] The heat sink assembly of claim 10, wherein a hydraulic diameter of the passage is at least one of the following: - inversely proportional to the second cross-sectional area of the first steam column, - larger than one dimension of the first steam column. [12] The heat sink assembly of claim 11, wherein the dimension of the first vapor column is perpendicular to the first cross-sectional area. [13] The heat sink assembly according to any one of claims 8 to 12, wherein a base of the first vapor column has a teardrop shape. [14] Three-dimensional steam chamber comprising: a base comprising a lower surface and a top surface; a plurality of vapor columns extending outwardly from the top surface of the base toward the stacked fin assembly, wherein a first cross-sectional area of a first vapor column of the plurality of vapor columns is greater than a second cross-sectional area of the first vapor column; and a vapor space defined within the base and the plurality of vapor columns. [15] A three-dimensional vapor chamber according to claim 14, wherein the first cross-sectional area is perpendicular to the second cross-sectional area. [16] A three-dimensional vapor chamber according to claim 14 or 15, wherein a first surface of the first vapor column is at least one of the following: - has a convex curvature and a second surface of the first vapor column is flat; - extends in a first direction and the second surface of the first vapor column extends in a second direction perpendicular to the first direction.

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