Abstract:
The present disclosure pertains to a heat sink having a base, a heat exchanger being thermally coupled to a top surface of the base, a housing having a chamber formed therein and being placed over the base with the heat exchanger enclosed within the chamber, an inlet connected to the inlet chamber for directing heat transfer medium into the heat sink, and an outlet connected to the outlet chamber for discharging the heat transfer medium from the heat sink, wherein the heat exchanger has a plurality of plates and a plurality of spacers, thereby providing for a plurality of channels.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of priority to U.S. Provisional Application No. 61/519,866, filed on Jun. 1, 2011, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Electronic devices generate a high concentration of heat. Increased computing speeds have resulted in a corresponding increase in the power density of the electronic devices. Existing heat sinks for heat sources such as microelectronics components have generally used air to directly remove heat from the heat source. However, air has a relatively low heat capacity. Such forced air cooling assemblies are suitable for removing heat from relatively low power heat sources. Heat dissipation devices employing high heat capacity liquid like water and water-glycol solutions are more particularly suited to remove heat from high power density heat sources. The cooling liquid used in these heat sinks removes heat from the heat source and then transfers heat to a remote location where the heat can be easily dissipated. 
       SUMMARY OF THE INVENTION 
       [0003]    The present disclosure pertains to a heat dissipation device having a base, a heat exchanger being thermally coupled to a top surface of the base, a housing having a chamber formed therein and being placed over the base with the heat exchanger enclosed within the chamber, an inlet connected to the inlet chamber for directing liquid into the heat sink, and an outlet connected to the outlet chamber for discharging the liquid from the heat sink, wherein the heat exchanger has a plurality of plates and a plurality of spacers, thereby providing for a plurality of channels. 
         [0004]    One aspect of the disclosure is a heat dissipation device wherein the plates and spacers are alternatively superposed. One aspect of the disclosure is a heat dissipation device wherein the base and the plates are made of a thermally conductive material. One aspect of the disclosure is a heat dissipation device wherein the spacers are made of a thermally conductive material. One aspect of the disclosure is a heat dissipation device wherein the heat exchanger further has a core, the plates have a hole, and the spacers have a hole, wherein the holes of the plates and spacers receive the core. One aspect of the disclosure is a heat dissipation device wherein the core is made of a thermally conductive material. One aspect of the disclosure is a heat dissipation device wherein the plates are annular. 
         [0005]    One aspect of the disclosure is a heat dissipation device wherein the chamber has an inlet chamber, outlet chamber, and heat exchanger chamber. One aspect of the disclosure is a heat dissipation device having a gasket and a slot for receiving the gasket. One aspect of the disclosure is a heat dissipation device having mounting brackets. One aspect of the disclosure is a heat dissipation device having a pump for circulating the flow of liquid to the heat sink. 
         [0006]    With those and other objects, advantages and features on the invention that may become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims, and the drawings attached hereto. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present invention and together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
           [0008]      FIG. 1  is a perspective view of a heat sink according to an exemplary embodiment. 
           [0009]      FIG. 2  is a perspective view of a heat sink according to an exemplary embodiment. 
           [0010]      FIG. 3  is a side view of a heat sink according to an exemplary embodiment. 
           [0011]      FIG. 4  is an exploded view of a heat exchanger according to an exemplary embodiment. 
           [0012]      FIG. 5  is a perspective view of a heat sink according to an exemplary embodiment. 
           [0013]      FIG. 6  is a perspective view of a heat sink according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    In the following detailed description, reference is made to the accompanying drawings which form a part hereof and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. 
         [0015]    A heat dissipation device or heat sink  100  can be incorporated into a heat dissipation system by way of example for cooling a heat source, for example, without limitation, an electronic device, hydraulic system, water heater, light emitting diode, laser, mold, solar collector, or the like. A pump moves a heat transfer medium, for example, without limitation, a liquid or gas, through a heat sink  100  to dissipate heat from the heat transfer medium. The liquid can be any liquid suitable for removing heat from a heat source, for example, without limitation, water, water-glycol solutions, or the like. The cooling system can have a fan and a radiator to further reduce the heat of the liquid. 
         [0016]    In one embodiment, as shown in  FIG. 1 , the heat sink  100  has a base  200  having a top surface and a central axis A substantially normal thereto. While the base  200  can be any shape, the base  200  is preferably rectangular in shape with the central axis A disposed at the center of the base  200 . The base  200  can have a contact surface for contacting the electronic device and absorbing heat produced thereby. 
         [0017]    In one embodiment, a housing  300  is fastened to the base  200  by conventional fasteners for example, without limitation, bolts. As shown in  FIG. 2 , the housing  300  has a top wall  310  and a peripheral sidewall  320  extending from the perimeter of the top wall  310  between the bottom surface of the top wall  310  of the housing  300  and the top surface of the base  200 . The top wall  310  and sidewall  320  define a chamber. The chamber preferably has a heat exchange chamber  410 , an inlet chamber  420 , and an outlet chamber  430 . In one embodiment, the bottom surface  321  of the sidewall  320  has a slot  330  to receive a gasket  600 . The gasket  600  ensures a tight seal of the chamber between the base  200  and the bottom surface  321  of the sidewall  320 , thereby preventing heat transfer medium from passing between the base  200  and the sidewall  320 . 
         [0018]    As shown in  FIGS. 3 and 4 , a heat exchanger  500  can be received by the heat exchange chamber  410  of the housing  300  with a bottom surface of the heat exchanger  500  thermally coupled to a top surface of the base  200 , a top surface  501  of the heat exchanger  500  in contact with a bottom surface of the top wall  310  of the housing  300 , and a central axis A in a position substantially normal to the top surface of the base  200 . The inner periphery of the sidewall  320  can be in spaced relationship with the outer edge  502  of the heat exchanger  500  so that heat transfer medium may circulate between the inner periphery of the sidewall  320  and the outer edge  502  of the heat exchanger  500 . The bottom surface of the top wall  310  can be in spaced relationship with the top surface  501  of the heat exchanger  500  so that heat transfer medium may circulate between the bottom surface of the top wall  310  and the top surface  501  of the heat exchanger  500 . 
         [0019]    The heat exchanger  500  can be substantially cylinder-shaped and has a plurality of plates  510  and spacers  520 . The heat exchanger  500  can be mechanically and/or thermally coupled to the base  200  thereby allowing conduction of heat from the base  200  to the heat exchanger  500 . While the plates  510  are preferably annular, the plates  510  can be any shape, for example, without limitation, elliptical, rectangular, teardrop, or the like. While the surface of the plates  510  is preferably smooth, the surface of the plates  510  can have, for example, without limitation, an undulated or wave-like surface, or a rough or rigid surface. In one embodiment, the annular plates  510  and spacers  520  are coaxially superposed, where the radius of the annular plates  510  is greater than the radius of the spacers  520 . In one embodiment, the annular plates  510  are in spaced relationship with the inner periphery of the sidewall  320  allowing heat transfer medium to circulate between the inner periphery of the sidewall  320  and the annular plates  510 . In one embodiment, as shown in  FIGS. 3 and 4 , the annular plates  510  and spacers  520  are alternatively superposed thereby defining channels  540  between the annular plates  510 , thereby increasing the heat dissipation rate without increasing the footprint size of the heat exchanger  500 . For example, a first annular plate  510  is stacked on the base  200 , a spacer  520  is stacked on the first annular plate  510 , a second annular plate  510  is stacked on the spacer  520 , and so forth until all the annular plates  510  and spacers  520  are alternatively superposed. In one embodiment, the annular plates  510 , spacers  520 , and channels  540  run in a horizontal plane substantially normal to the central axis A. The channels  540  allow for the heat transfer medium to travel around the annular plates  510 , spacers  520 , and base  200  thereby removing heat from the annular plates  510 , spacers  520 , and base  200 . 
         [0020]    The inlet chamber  420  and the outlet chamber  430  are in heat transfer medium communication with each other through the heat exchange chamber  410  and the channels  540  formed within the heat exchanger  500 . 
         [0021]    In one embodiment, the heat exchanger  500  has a core  530  that can be mechanically and/or thermally coupled to the base  200  thereby allowing for the conduction of heat from the base  200  to the core  530 . As shown in  FIG. 4 , the base can have a hole  220  for receiving the core  530  so that the bottom surface of the core  530  substantially lies in the same plane as the bottom surface of the base  200 . As shown in  FIGS. 3 and 5 , the plates  510  and spacers  520  can be mechanically and/or thermally coupled to the core  530  thereby allowing for the conduction of heat from the core  530  to the plates  510  and spacers  520 . As shown in  FIG. 4 , the annular plates  510  and spacers  520  can have a hole  511  for receiving the core  530 . The annular plates  510  can be flattened between the spacers  520  when pressed onto the core  530 , thereby preventing the annular plates  510  from becoming damaged when pressed onto the core  530  and allowing for the annular plates  510  to have a thin thickness. In one embodiment, the annular plate  510  has a thickness of 0.4 mm and the spacer  520  has a thickness of 0.4 mm. The annular plates  510  and spacers  520  are mechanically and thermally coupled to the core  530  thereby allowing for the conduction of heat from the core  530  to the annular plates  510  and spacers  520 . 
         [0022]    An inlet  700  can be disposed in the housing  300  for directing the heat transfer medium to the inlet chamber  420  and to the heat exchanger  500 . An outlet  800  can be disposed in the housing  300  of the heat sink  100  for discharging the heat transfer medium. The inlet  700  and/or outlet  800  can be disposed on the top wall  310  of the housing  300  or the sidewall  320  of the housing  300 . The heat transfer medium flows through the inlet  700 , into the inlet chamber  420 , through the channels  540  in the heat exchanger  500 , into the outlet chamber  430 , and through the outlet  800  where the heat transfer medium exits the heat sink  100 . In one embodiment, the heat transfer medium flows substantially normal to the heat exchanger  500  to enhance heat dissipation from the heat exchanger  500 . The inlet  700  and outlet  800  can have a compression fitting  710  for sealing the engagement of an inlet tube  720  to the inlet  700 , and outlet tube  820  to the outlet  800 , respectively, in a manner that prevents or reduces the heat transfer medium from flowing between the inlet tube  720  and the inlet  700  or the outlet tube  820  and the outlet  800 . 
         [0023]    Mounting brackets  900  engage the heat sink  100  and allow for the heat sink  100  to be secured in a manner that allows for the heat sink  100  to engage the heat source. In one embodiment, the mounting brackets  900  juxtapose the base  200  and the bottom surface  321  of the sidewall  320 . The mounting brackets  900  can be secured to the heat source by conventional fasteners for example, without limitation, bolts. 
         [0024]    During operation, heat generated by a heat source is first conducted to the base  200 . The inlet tube  720  directs the heat transfer medium through the inlet  700  into the inlet chamber  420 . The heat is transferred to the heat transfer medium as the heat transfer medium impinges the top surface of the base  200 , annular plates  510 , and spacers  520 . The heat transfer medium flows through the channels  540  and into the outlet chamber  430  resulting in an upwelling of the heat transfer medium through the outlet  800 . The heated heat transfer medium exits the heat sink  100  through the outlet  800  and, after being cooled, the heated heat transfer medium is returned to the heat sink  100  to perform another working cycle. 
         [0025]    The base  200 , heat exchanger  500 , core  530 , annular plates  510 , and spacers  520  can be constructed of a thermally conductive material, such as copper, aluminum, silver, silver alloy, copper alloy, aluminum alloy, ferrous alloy, carbon based, ceramic or polymeric materials, or the like. However, any thermally conductive material suitable for absorbing and transferring heat may be utilized. Accordingly, the scope of the invention should not be limited to the type of material utilized for the base  200 , heat exchanger  500 , core  530 , annular plates  510 , or spacers  520 . 
         [0026]    The foregoing has described the principles, embodiments, and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments described above, as they should be regarded as being illustrative and not as restrictive. It should be appreciated that variations may be made in those embodiments by those skilled in the art without departing from the scope of the present invention. 
         [0027]    Modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described herein.