Abstract:
A heat dissipation device includes a heat sink and two conductor bases. The heat sink includes two base plates attached to a graphics card and thermally connecting with two graphics processing units (GPUs) mounted on the graphics card, and a plurality of fins soldered on tops of the base plates. The conductor bases connect with the base plates of the heat sink and thermally connect with other electronic components mounted around the GPUs thereby to dissipate heat generated by the other electronic components. The GPUs and the other electronic components have different heights.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a heat dissipation device, and more particularly to a heat dissipation device for computer add-on cards. 
   2. Description of Related Art 
   In order to enhance computers functions and performance, add-on units, including graphics cards, are often installed in the computers. The graphics cards each comprise a separate processor, called GPU (graphics processor unit). The GPU generates a large amount of heat during operation. When the temperature of the GPU exceeds a certain level, the GPU may malfunction, or in the worst case fail outright. For this reason, a heat dissipation device is commonly installed on the GPU to dissipate the heat generated by the GPU and other electronic components adjacent to it into ambient air. 
   Generally, the heat dissipation device comprises a heat sink and a base plate attached to electronic components mounted on the graphics card. However, if one electronic component has a height different from that of an adjacent electronic component, the base plate is not able to tightly contact with the electronic components with different heights; as a result, a large heat resistance will exist between the electronic components and the base plate, which will adversely affect the heat dissipation of the electronic components. 
   What is needed, therefore, is a heat dissipation device which can effectively dissipate heat generated by electronic components on a graphics card, wherein the electronic components have different heights. 
   SUMMARY OF THE INVENTION 
   A heat dissipation device includes a heat sink and two conductor bases. The heat sink includes two base plates attached to an add-on card and thermally connecting with two primary electronic components mounted on the added-on card, and a plurality of fins located at tops of the base plates. The conductor bases connect with the base plates of the heat sink and thermally connect with other electronic components around the primary electronic components to dissipate heat generated by the other electronic components. The primary electronic components and the other electronic components have different heights. 
   Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Many aspects of the present apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus and method. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
       FIG. 1  is an exploded, isometric view of a heat dissipation device in accordance with a preferred embodiment of the present invention and a graphics card; 
       FIG. 2  is an assembled view of  FIG. 1 ; 
       FIG. 3  is an enlarged view of conductor bases of the heat dissipation device of  FIG. 1 ; 
       FIG. 4  is a view similar to  FIG. 2 , but shown from a bottom aspect, wherein the graphics card is taken away for clarity; and 
       FIG. 5  is an enlarged view of a fixing bracket of the heat dissipation device of  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1-2 , a heat dissipation device in accordance with a preferred embodiment of the present invention is illustrated. The heat dissipation device is mounted on a graphics card  50  in a computer enclosure (not shown) and used for dissipating heat generated by a pair of GPUs  52  mounted on the graphics card  50  and other electronic components  53 , 54  mounted around the GPUs  52 . The heat dissipation device comprises a heat sink  30  and two conductor bases  71 ,  75 . 
   The GPUs  52  are separately located at a top surface of the graphics card  50 , and the electronic components  53 , 54  are located around the GPUs  52 . A plurality of through holes  56  are defined around the GPUs  52 . A mounting plate  51  is perpendicularly formed at a rear edge of the graphics card  50 . A flange  510  is formed at an end of the mounting plate  51 . 
   The heat sink  30  generally comprises a fin group  32 , a pair of base plates  34  separately located at a bottom surface of the fin group  32 , a plurality of heat pipes  40  thermally connecting the fin group  32  and the base plates  34 , and a lid  33  mounted on a top of the fin group  32 . A fan (not labeled) is mounted in a recessed portion defined in the top of the fin group  32 . The lid  33  covers the fan, and defines an opening (not labeled) in alignment with the fan. 
   The fin group  32  comprises a plurality of parallel fins  322 . The fin group  32  is cut away at a lower portion at opposite front and rear sides thereof to define a pair of opposite cutouts  320 . Each base plate  34  has a rectangular shape and has a bottom face for contacting with the GPU  52 . Four ears (not labeled) are formed at four corners of each base plate  34 . A mounting hole  346  is defined in each of the four ears (not labeled) of each of the base plates  34  for providing a passage of a corresponding fastener (not shown) to mount the heat dissipation device on the graphics card  50 . A screw hole  348  is defined in each of three of the four ears and located beside the corresponding mounting holes  346 . A bottom surface of the base plate  34  has three recesses (not labeled) in the three ears, respectively, wherein the screw holes  348  are defined. A pair of adjoining semicircular grooves  344  are defined at a top surface  342  of the base plate  34  to receive the corresponding heat pipes  40  therein. 
   The conductor bases  71 ,  75  are attached on top surfaces of the electronic components  53 ,  54  for dissipating heat generated therefrom. 
   Referring to  FIG. 3 , the conductor base  71  comprises three elongated rectangular bodies  711 ,  712 ,  713 . The bodies  711 ,  713  are parallel to each other. The body  712  is located between the bodies  711 ,  713  and perpendicularly interconnects them to form a U-shaped configuration. Three through holes  714  are defined in the conductor base  71  aligned with the corresponding through holes  56 . Two of the through holes  714  are located at opposite ends of the body  712  and another through hole  714  is located at a corner of an outmost end of the body  711 . An extension portion  716  extends outwardly and inclinedly from an end of the body  711 . A cutout (not labeled) is defined in an inner side of a center of the body  711  to prevent the heat pipes  40  of the heat sink  30  and the conductor base  71  from interfering with each other when the heat sink  30  and the conductor base  71  are assembled together. An extension plate  717  extends outwardly from an outmost end of the body  713 . A cantilever  715  is formed to extend from an inner side of each of the bodies  711 ,  712 ,  713 . The cantilever  715  of the body  711  is located adjacent to the cutout of the body  711 . The cantilever  715  of the body  712  extends perpendicularly from an end of the body  712  adjacent to the body  713 . The cantilever  715  of the body  713  extends perpendicularly near an end of the extension plate  717 . Each of the cantilevers  715  defines a mounting hole  7152  at a free end thereof, which is aligned with a corresponding screw hole  348  of the base plate  34 . 
   The conductor base  75  is similar to the conductor base  71 . The conductor base  75  comprises two elongated rectangular bodies  751 ,  752 . The bodies  751 ,  752  perpendicularly interconnect each other to form an L-shaped configuration. Three through holes  753  are defined in the conductor base  75  and aligned with the corresponding through holes  56  of the graphics card  50 . An extension portion  754  extends outwardly and inclinedly from an end of the body  751 . A recess (not labeled) is defined at a central of the body  751  to prevent the heat pipes  40  of the heat sink  30  and the conductor base  75  from interfering with each other. Two cantilevers  755  are formed to extend from inner sides of the bodies  751 ,  752 . The cantilever  755  of the body  751  extends perpendicularly from the body  751  at a position adjacent to the recess of the body  751 . The cantilever  755  of the body  752  extends perpendicularly from an end of the body  752 . Each of the cantilevers  755  defines a mounting hole  7552  at a free end thereof, which is aligned with a corresponding screw hole  348  of the base plate  34 . 
   After the base plates  34  are assembled with the fin group  32 , screws (not labeled) extend through the through holes  7152 ,  7552  of the cantilevers  715 ,  755  of the conductor bases  71 ,  75  to screw in the screw holes  348  of the base plates  34  of the heat sink  30  to assemble the conductor bases  71 ,  75  and the base plates  34  together. The free ends of the cantilevers  715 ,  755  are received in the recesses of the base plates  34 , with bottom surfaces thereof are coplanar with the bottom surfaces of the base plates  34 . The configuration of the conductor bases  71 , 75  depends on the arrangement of the electronic components  53 , 54  mounted on the graphics card  50 . 
   Referring to  FIG. 4 , after the conductor bases  71 ,  75  and the base plates  34  are assembled together, some gaps  323  are defined between the conductor bases  71 ,  75  and the base plates  34  to receive therein some other components  55 , such as capacitors which are higher than the GPUs  52  and the electronic components  53 ,  54 . The GPUs  52  have a height different from that of the electronic components  53 ,  54 . More specifically, top edges of the GPUs  52  are located above top edges of the electronic components  53 ,  54 , as viewed from  FIG. 1 . The thickness of the conductor bases  71 ,  75  are determined on the thickness of the electronic components  53 ,  54  to make sure that the conductor bases  71 ,  75  can tightly contact with the electronic components  53 ,  54 . 
   The heat dissipation device further comprises two back plates  90  to reinforce the graphics card  50 . The back plates  90  are separately positioned below the bottom side of the graphics card  50 . Each back plate  90  is cross-shaped and defines four through holes  902  therein. Screws (not shown) extend through the through holes  902  of each back plate  90  and the graphics card  50  to screw in the mounting holes  346  of the bases  34  to mount the back plates  90  to the graphics card  50 . Thus, the heat dissipation device is mounted to the graphics card  50 . 
   The heat dissipation device further comprises a fixing bracket  10  which helps to attach the heat sink  30  to a panel of the computer enclosure, whereby a portion of weight of the heat sink  30  can be supported by the computer enclosure; thus a pressure exerted on the graphics card  50  by the weight of the heat sink  30  can be reduced. 
   Referring to  FIGS. 4-5 , the fixing bracket  10  is made from a metallic sheet and comprises a first fixing bracket  11  and a second fixing bracket  15 . 
   The first fixing bracket  11  comprises a connecting portion  111 , an extension portion  113  extending from an end of the connecting portion  111  and a securing portion  115  extending perpendicularly from a free end of the extension portion  113 . The connecting portion  111  has an elongated, rectangular configuration and engages with a rear edge of the fin group  32  at the cutout  320  adjacent to the mounting plate  51  of the graphics card  50 . The extension portion  113  has a curved configuration to reinforce the elasticity of the first fixing bracket  11 . 
   The second fixing bracket  15  is similar to the first fixing bracket  11  and comprises a connecting portion  151 , an extension portion  153  and a securing portion  155 . The connecting portion  151  has an elongated rectangular shape and soldered to a lateral side of the fin group  32 . The extension portion  153  extends from an end of the connecting portion  151 . The securing portion  155  extends perpendicularly from the extension portion  153  and has a configuration similar to that of the securing portion  115  of the first fixing bracket  11 . 
   In assembly, the connecting portions  111 ,  151  of the fixing bracket  10  are fixed to the fin group  32  and the securing portions  115 ,  155  are overlapped each other. Screws (not labeled) extend through the securing portions  115 ,  155 , the flange  510  of the mounting plate  51  of the graphics card  50  and the panel of the computer enclosure to mount the first and the second fixing brackets  11 ,  15  to the computer enclosure. 
   It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereto described merely being preferred or exemplary embodiments of the invention.