Abstract:
A hybrid liquid-air cooling system which may be easily adapted to provide a liquid cooling mechanism for use with a wide range of heat sources on components or adapter boards ( 10 ) in a personal computer system, and which functions cooperatively with an air cooling system ( 106 ). The liquid cooling mechanism includes a cold plate component ( 100 ) adapted for use with a wide range of applications, and Is secured in place by an exchangeable mounting clip ( 104 ) which eliminates the need to breach the liquid cooling system flow pathways ( 102 ) to insert, remove, or replace heat source components. The cold plate component ( 100 ) functions cooperatively with an air cooling structure ( 106 ) consisting generally of an aluminum heat sink, cooling fins ( 106   a ), heat pipes ( 106   b ), and a cooling fan ( 106   c ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is related to, and claims priority from, U.S. Provisional Patent Application Ser. No. 60/893,434 filed on Mar. 7, 2007, and which is herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention is related generally to a system for cooling component circuit boards, electronic components, and heat sources associated with electronic components, and is directed specifically to a hybrid liquid-air cooling system adapted for use in cooling integrated circuit components such as those found in a personal computer system. 
         [0003]    Personal computer systems which are designed for desktop or under-desk use, and which are typically characterized by a main-board or motherboard housed in a chassis or case. These auxiliary components may include network adapter circuit boards, modems, specialized adapters, and graphics display adapters. These auxiliary components may receive power through the connection to the motherboard, or through additional connections directly to a system power supply contained within the chassis or case. Additional components which generate heat, such as hard drives, disk drives, media readers, etc. may further be contained within the chassis or case, and coupled to the system power supply and motherboard as needed. 
         [0004]    During operation, the motherboard and various auxiliary components consume power and generate heat. To ensure proper functionality of the computer system, it is necessary to regulate the operating temperatures inside the environment of the chassis or case. Individual integrated circuits, especially memory modules and processors, may generate significant amounts of heat during operation, resulting in localized hot spots within the chassis environment. The term “processors”, as used herein, and as understood by one of ordinary skill in the art, describes a wide range of components, which may include dedicated graphics processing units, microprocessors, microcontrollers, digital signal processors, and general system processors such as those manufactured and sold by Intel and AMD. Failure to maintain adequate temperature control throughout the chassis environment, and at individual integrated circuits, can significantly degrade the system performance and may eventually lead to component failure. 
         [0005]    Traditionally, a cooling fan is often associated with the system power supply, to circulate air throughout the chassis environment, and to exchange the high temperature internal air with cooler external air. However, as personal computer systems include increasing numbers of individual components and integrated circuits, and applications become more demanding on additional processing components such as graphics display adapters, a system power supply cooling fan may be inadequate to maintain the necessary operating temperatures within the chassis environment. 
         [0006]    Specialized liquid cooling systems are available for some components in a personal computer system. Specialized liquid cooling systems typically required a coolant circulation pathway, which routes a thermal transfer liquid between a heat exchanger such as a radiator and a heat source, such as a CPU, GPU, microprocessor or transformer. Specialized liquid cooling systems are well adapted for maintaining adequate operating temperatures for individual components. However, these specialized liquid cooling systems are not easily adapted for use with a wide variety of components or adapter boards in a personal computer system. Furthermore, once such liquid cooling systems are installed, it is difficult to replace, insert, or remove components requiring cooling from the system, as the liquid cooling system must either be drained or breached to facilitate the replacement, insertion, or removal. 
         [0007]    Accordingly, it would be advantageous to provide a hybrid liquid-air cooling system which may be easily adapted to provide a liquid cooling mechanism for use with a wide range of components in a personal computer system, and which functions cooperatively with an air cooling system. It would be further advantageous to provide a liquid-air cooling system which may be easily detached from an associated heat source without draining of any liquid coolant or breaching of the coolant flow pathways, enabling replacement, addition, or removal of heat source components such as upgraded processors. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    Briefly stated, the present disclosure provides a hybrid liquid-air cooling system which may be easily adapted to provide a liquid cooling mechanism for use with a wide range of components in a personal computer system, and which functions cooperatively with an air cooling system. The liquid cooling mechanism includes a cold plate component adapted for use with a wide range of applications, such as different types of integrated circuits or processors, and which is removably secured in place in proximity to the heat source by an exchangeable mounting clip. The cold plate component may optionally be configured to function cooperatively with an air cooling structure consisting generally of an aluminum heat sink, cooling fins, heat pipes, and a cooling fan. A shroud or duct surrounds the cold plate component and the air cooling structure, facilitating a flow of air across a thermal gradient from hot to cold. 
         [0009]    The foregoing features, and advantages set forth in the present disclosure as well as presently preferred embodiments will become more apparent from the reading of the following description in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0010]    In the accompanying drawings which form part of the specification: 
           [0011]      FIG. 1  is a perspective external view of a hybrid liquid-air cooled graphics display adapter of the present invention; 
           [0012]      FIG. 2  is a perspective view of the hybrid liquid-air cooled graphics display adapter of  FIG. 1 , with the external components shown in phantom; 
           [0013]      FIG. 3  is a view similar to  FIG. 2 , but from a different orientation; 
           [0014]      FIG. 4  is a view of a cold plate component of the present invention installed on a graphics display adapter; 
           [0015]      FIG. 5  is an underside perspective view of the cold plate component of  FIG. 4 , installed over a graphics processor which is shown in phantom; 
           [0016]      FIG. 6A  is a topside perspective view of the cold plate component of  FIG. 4 ; 
           [0017]      FIG. 6B  is a sectional view of an attachment point for the cold plate component of  FIGS. 5 and 6A ; 
           [0018]      FIG. 7  is a perspective view of an embodiment of a liquid manifold of the present invention; 
           [0019]      FIG. 8  is a perspective view of an alternate embodiment of a liquid manifold of the present invention; 
           [0020]      FIGS. 9A through 9D  illustrate the placement of an exchangeable mounting clip over a liquid manifold of the present invention for attachment to an adapter board; 
           [0021]      FIG. 10  is a perspective view of a liquid cooling system of the present invention operatively coupled to a coolant fluid loop and heat exchanger; and 
           [0022]      FIG. 11  is a perspective view of a liquid cooling system of the present invention having components coupled in a chain configuration within the coolant fluid loop. 
       
    
    
       [0023]    Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings. It is to be understood that the drawings are for illustrating the concepts set forth in the present disclosure and are not to scale. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]    The following detailed description illustrates the invention by way of example and not by way of limitation. The description enables one skilled in the art to make and use the present disclosure, and describes several embodiments, adaptations, variations, alternatives, and uses of the present disclosure, including what is presently believed to be the best mode of carrying out the present disclosure. 
         [0025]    While the present disclosure is described generally in connection with the use of the present invention on a graphics display adapter, those of ordinary skill in the art will readily recognize that the present invention is not limited to use on a graphics display adapter, and may easily be utilized with any of a wide variety of heat sources commonly found in a personal computer system without departing from the scope of the invention. Turning to  FIG. 1-4 , a cold plate  100  of the present invention is shown secured over a video or graphic processing unit of a graphics display adapter  10 . The cold plate  100  is shown configured for connection to an existing liquid cooling loop  102  via any suitable liquid pathway. Preferably the liquid cooling loop  102 , which is not directly part of the present invention, provides all necessary components for circulating a flow of liquid coolant to and from the cold plate  100 , thereby drawing heat away from the various heat-generating components in proximity to the cold plate  100 . 
         [0026]    Preferably, the cold plate  100  is made from a material which facilitates a transfer of heat, such as a metal like copper or aluminum, or an alloy. The cold plate  100  is of a generic design and may be operatively secured in contact with different types of heat sources such as processors, power supplies, or graphic display cards by utilizing an exchangeable mounting clip  104  associated with the selected heat source. The cold plate  100  may be mounted as a member of a larger heat conducting structure  106  best seen in  FIGS. 1-3 . The heat conducting structure  106  may be made from any suitable material, such as aluminum or copper, and preferably contacts each hot spot or component on the graphics display card  10  on one or more sides (with exception of the video or graphics processing unit, as the cold plate  100  is cooling this) to act as a heat sink. Optionally, thermal energy may be further drawn out of the aluminum structure by air convection across cooling fins  106 A, heat pipes  106 B, and a fan  108 . Everything is preferably enclosed within a duct or shroud  110  that will ensure that the heated air is blown out of the personal computer case or otherwise routed away from the graphics display adapter. 
         [0027]    Optionally, the cold plate  100  itself may incorporate external cooling fins to facilitate cooling by the air stream in addition to the cooling by the flow of cooling liquid from the liquid cooling loop  102 . The inclusion of external cooling fins on the cold plate  100  is particularly advantageous for situations where the liquid cooling loop  102  has reached a thermal capacity, thereby enabling off loading of additional thermal input by air cooling. 
         [0028]    By separating the cold plate  100  for cooling the video or graphics processing unit from the rest of the cooling system, it is possible to design a generic cold plate  100  that can be utilized to fit over multiple styles and configurations of video and graphics processing units, meaning that the manufacturer of the graphics display adapter  10  does not have to carry a large number of different cold plate products, but can do with one generic liquid cooling solution merely exchange the aluminum parts and/or the mounting clips  104  as required for different applications. Furthermore, when a component being cooled by an associated cold plate  100  is to be removed, replaced, or added, the generic design of the cold plate  100  and exchangeable mounting clip  104  enables the cold plate  100  to be disconnected from the component without requiring any draining or breaching of the liquid coolant circulation pathways, allowing the component to be replaced, added, or removed without difficulty. 
         [0029]    An additional benefit of utilizing a liquid-air hybrid cooling system of the present invention is that the form factors of the various other cooling components  106 , such as the aluminum cooling structure, may be made smaller when compared to an all-air cooled solution, due to the fact that the air cooling components do not have to cool the highest heat outputting component, i.e. the video or graphics processing unit, which is now cooled by the liquid cooling loop  102  through contact with the cold plate  100 . 
         [0030]    This invention is basically different in the sense that it is considered as a single cooling system, but is based on a combination of different technologies. As mentioned before the cold plate  100  is configured as a generic component to cooperatively function with the air cooled components  106 , which may vary according to the configuration or design of the graphics display adapter or component board  10 . 
         [0031]    As shown in  FIGS. 7 and 8 , the specific configuration of the cold plate fluid manifold  110 A, or  1108 , which is coupled to an upper surface of the cold plate  100  to form an enclosed chamber in the liquid cooling loop  102  to facilitate circulation of the cooling liquid throughout the coolant flow circuit between a fluid delivery  102   in  and fluid return line  102   out , may be varied as required. For example, as shown in  FIG. 7 , a fluid flow diverter  112  is disposed between the cooling liquid input  102   in  and output  102   out  ports in the cold plate fluid manifold  110 A. When the cold plate fluid manifold  110 A is disposed over the surface of the cold plate  100  which, in turn is in contact with the upper surface of a video or graphics processing unit, the fluid circulation chamber is formed within which cooling fluid may circulate to draw heat from the surrounding surfaces, particularly heat conveyed from the heat source by the cold plate  100 . During use, cooling liquid flows into the cold plate fluid manifold  110 A through the liquid input port  102   in , and must circulate around the fluid flow diverter  112  before existing the fluid manifold  110 A through the liquid output port  102   out . The flow of fluid ensures a uniform cooling of the various surfaces in contact with the cold plate  100 , such as a video or graphics processing unit. The fluid flow diverter  112  may take many forms, including a multitude of pins and/or fins, and may be formed either on the cold plate fluid manifold as at  110 A, or on the surface of the cold plate  100  which is exposed to the fluid chamber. Alternatively, as shown in  FIG. 8 , the fluid flow diverter  112  may be eliminated, and fluid allowed to flow freely within the fluid circulation chamber between the cold plate  100  and the fluid manifold as at  110 B. 
         [0032]    To secure the cold plate  100  in place over a video or graphics processing unit, a variety of different attachment means may be utilized.  FIGS. 9A-9D  illustrate the use of an interchangeable attachment bracket or mounting clip  104  to secure the cold plate  100 , together with the coupled fluid manifold  110 A,  110 B in place on an adapter board. The interchangeable attachment bracket  104  is designed with a set of mounting tabs  104 A and a central portion  104 B having an opening  104 C sized to slip-fit over the cold plate  100  and fluid manifold  110 , as shown in  FIGS. 9A and 9B . Once in place over the cold plate  100  and fluid manifold  110 , the attachment bracket  104  is rotated into a co-planar configuration with the cold plate  100  and fluid manifold  110 , as shown in  FIGS. 9C and 9D , preferably engaging a set of opposing flanges  114  on the peripheral edges of the cold plate  100 . The attachment bracket  104  includes a set of tabs  104 A through which screws, bolts, or clips may be installed to secure the attachment bracket  104  and the cold plate  100 /fluid manifold  110  in place against an electronic component to be cooled. 
         [0033]    For example, as shown in FIGS.  5  and  6 A- 6 B, the cold plate  100  may be secured in place over the heat source with a spring bias retention system  116 , wherein threaded connectors  118  are utilized to hold attachment springs  120  in place against the tabs  104 A on the attachment bracket  104 . The springs  120  provide a bias force holding the cold plate  100  against the surface of the heat sink. Those of ordinary skill in the art will recognize that the specific configuration of the tabs  104 A on the attachment bracket  104  may be varied in position, size, and number, as required for specific applications, and that the attachment means may be spring biased or secured by any other suitable method of affixation. Accordingly, it will be further understood that by providing a number of different attachment brackets  104 , a single cold plate design  100  may be readily used in a wide range of attachment applications without requiring custom designs. 
         [0034]    For example, as shown in  FIG. 10 , a single cold plate  100  and fluid manifold  110  may be secured in place over a heat source such as a main-board processing unit, or one or more graphics processing units in parallel or series, and coupled to coolant fluid loop  102  and heat exchanger  102 Hx. Alternatively, a set of cold plates  100  may be secured in place over a main-board processing unit, a graphics processing unit, and an audio processing unit, and then each may be coupled in series to a coolant fluid loop  102  and heat exchanger  102 Hx to enable cooling of multiple components in a system utilizing the cold plates  100  of the present invention. The use of an adaptable attachment bracket  104  for securing the cold plates  100  in place over a variety of components enables an end-user to utilize the cooling system of the present invention in a flexible manner to provide cooling to one or more heat sources, and to expand or contract the size of the system as necessary to accommodate the addition or removal of components. 
         [0035]    As various changes could be made in the above constructions without departing from the scope of the disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.