Abstract:
A heat dissipation assembly ( 10 ) includes a heat sink ( 20 ) and a cover ( 30 ). The heat sink includes a base ( 22 ) and a plurality of fins ( 24 ) formed on a bottom surface of the base. A depression ( 220 ) is formed in a top surface of the base and has thermal interface material ( 40 ) received therein. The cover is removably secured to the top surface of the base of the heat sink and covers the depression.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention generally relates to a heat dissipation assembly having a heat sink, and more particularly to a heat dissipation assembly protecting thermal grease from contamination during transportation. 
         [0003]    2. Description of Related Art 
         [0004]    As computer technology continues to advance, electronic components such as central processing units (CPUs) of computers provide faster operational speeds and increased functional capabilities. When a CPU operates at high speed in a computer enclosure, its temperature increases greatly. It is necessary to dissipate the generated heat quickly, for example by using a heat sink attached to the CPU in the enclosure. This allows the CPU and other electronic components in the enclosure to function within their normal operating temperature ranges, thereby assuring the quality of data management, storage and transfer. 
         [0005]    To improve heat conductivity between a heat sink and a CPU, thermal interface material such as thermal grease is often applied to a bottom face of the heat sink. However, thermal grease may contaminate surrounding articles or be contaminated by dust or foreign particles before attachment to the CPU. 
         [0006]    What is needed, therefore, is a heat sink providing protection for thermal grease from contamination. 
       SUMMARY 
       [0007]    An exemplary embodiment of the present invention provides a heat dissipation assembly. The heat dissipation assembly includes a heat sink and a cover. The heat sink includes a base and a plurality of fins formed on a bottom surface thereof. A depression is formed in a top surface of the base and has thermal interface material received therein. The cover is removably secured to the top surface of the base of the heat sink and covers the depression. 
         [0008]    Other advantages and novel features of the present invention will become more apparent from the following detailed description of embodiments when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an exploded view of a heat dissipation assembly in accordance with an embodiment of the present invention. 
           [0010]      FIG. 2  is an assembled, isometric view of the heat dissipation assembly of  FIG. 1 . 
           [0011]      FIG. 3  is an assembled, isometric view of the heat dissipation assembly in accordance with another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Reference will now be made to the drawing figures to describe the embodiments in detail. 
         [0013]    Referring to  FIGS. 1-2 , a heat dissipation assembly  10  in accordance with an embodiment of the present invention is illustrated. The heat dissipation assembly  10  includes a heat sink  20 , thermal interface material  40  and a cover  30 . The thermal interface material  40  can be thermal grease which is applied in the heat sink  20 . The cover  30  is deployed on the heat sink  20 . 
         [0014]    The heat sink  20  includes a rectangular base  22  and a plurality of fins  24  formed on a bottom surface thereof. A rectangular depression  220  is formed in a top surface of the base  22 . The depression  220  is defined by a bottom wall  222  and four sidewalls  224  extending from a periphery of the bottom wall  222 . 
         [0015]    The thermal interface material  40  is uniformly spread on a middle portion of the bottom wall  222 . The thickness of the thermal interface material  40  is less than a depth of the depression  220 . In other words, a top surface of the thermal interface material  40  is below the top surface of the base  22 . In another embodiment, the thermal interface material  40  may be uniformly spread on the bottom wall  222  and the sidewalls  224  so that a large heat exchanging surface is obtained between the heat sink  20  and a heat source (not shown), such as a CPU. The heat source can be positioned to protrude into the depression  220 . 
         [0016]    The cover  30  is removably attached to the top surface of the base  22 . The cover  30  is a flat sheet and may be divided into a rectangular main body  32  and a triangular tab  34 . The main body  32  is larger than that of the depression  220  so as to cover the depression  220 . The tab  34  is integrally formed with the main body  32  and extends beyond an edge of the top surface of the base  22 . The width of the tab  34  is gradually reduced from the main body  32  towards a free end of the tab  34 . 
         [0017]    The cover  30  may be of plastic sheeting, and may be attached to the base  22  via a layer of glue spread on the base  22  in the vicinity of a periphery of the depression  220 . In another embodiment, the cover  30  may be an adhesive tape, which can be directly attached to the top surface of the base  22  to cover the thermal interface material  40  in the depression  220  of the heat sink  20 . 
         [0018]    When the cover  30  is attached to the top surface of the base  22 , the thermal interface material  40  is enclosed by the cover  30  and the depression  220 . Thus, the thermal interface material  40  is protected from contamination before the heat sink  20  is attached to the heat source. 
         [0019]    Prior to assembling the heat sink  20  to the heat source, the tab  34  can be easily employed to peel the cover  30  away from the heat sink  20  to expose the thermal interface material  40 . The heat sink  20  and the heat source are then assembled together by a known procedure. By the provision of the cover  30 , the thermal interface material  40  can be applied in the heat sink  20  in advance, thereby simplifying assembly of the heat sink  20  and the heat source. Since the cover  30  is flat, the possibility of dislodgement from the heat sink  20  by other components in a direction parallel to the cover  30 , is greatly reduced. 
         [0020]      FIG. 3  shows a heat dissipation assembly in accordance with another embodiment of the present invention, differing from heat dissipation assembly  10  only in the structure of the cover  30   a . The cover  30   a  includes a rectangular main body  36  and a lateral wall  38 . The main body  36  is flat and is the same size as the base  22 . The lateral wall  38  extends downwardly and perpendicularly from a peripheral edge of the main body  36 . 
         [0021]    When the cover  30   a  is mounted on the base  22 , the main body  36  entirely contacts the top surface of the base  22  except for a portion above the depression  220 . The lateral wall  38  is in close contact with four sides of the base  22  so that the cover  30   a  is mounted on the base  22 . 
         [0022]    It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.