Abstract:
A protection structure for a thermal conducting medium of a heat dissipation structure installed on the heat dissipation device at the position on which the thermal conducting medium is coated. The protection structure has a bottom surface to cover the thermal conducting medium, a side wall extending along and projecting from a periphery of the bottom surface to form a space for receiving the thermal conducting medium and a portion of the heat dissipation device, and a support structure protruding from the bottom surface to avoid a direct contact between the thermal conducting medium and the bottom surface.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a protection structure for a thermal conducting medium of a heat dissipation device, and more particular, to a protection structure installed on the heat dissipation device at the position on which the thermal conducting medium is coated. 
   The commonly seen heat dissipation device such as the aluminum extrusion type heat dissipation device is attached on a central processing unit (CPU) to aid in heat dissipation when the central processing unit is operating. Thereby, the central processing can operate under a tolerable working temperature. Before the heat dissipation device is attached on the central processing unit, an adequate amount of thermal conducting medium such as thermal conductive paste is coated on the heat dissipation device, such that a close contact between the heat dissipation device and the central processing unit can be ensured. 
   The thermal conducting medium is typically in the form of a paste that easily cause adherence of dust and contamination. In case the heat dissipation device is dropped or in contact with external object before being attached to the central processing unit, the thermal conducting effect will be greatly degraded by the dust or contamination. In addition, the amount of the thermal conducting medium applied to the heat dissipation device is also a crucial parameter that affects the heat dissipation performance. Therefore, if the thermal conducting medium is coated by the end user who does not own a proper judgment of the amount, the heat dissipation performance may be degraded by improper amount of thermal conducting medium. If the thermal conducting medium is coated before the final assembly, dust and contamination is easily attached to the heat dissipation device, which again, causes degradation of heat dissipation. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides a protection structure for a thermal conducting medium of a heat dissipation device. The protection structure covers the thermal conducting medium to prevent dust and contamination adhered thereto. 
   The present invention further provides a protection structure for a thermal conducting medium of a heat dissipation device which also covers the heat dissipation device to provide a complete package of the heat dissipation device. 
   The protection structure provided by the present invention comprises a bottom surface to cover the thermal conducting medium, a side wall extending along and projecting from a periphery of the bottom surface to form a space for receiving the thermal conducting medium and a portion of the heat dissipation device, and a support structure protruding from the bottom surface to avoid a direct contact between the thermal conducting medium and the bottom surface. The support structure includes at least one pair of semi-spherical bumps, one pair of parallel ribs, or one pair of elongate ridges extending across the bottom surface. In the embodiment when the support structure includes a pair of elongate ridges extending across the bottom surface, the space formed by the sidewall is divided into a central space for receiving the thermal conducting medium and two spaces at two opposing sides of the central space. Preferably, the dimension of the central space is larger than the surface area of the thermal conducting medium. 
   The protection structure may further comprises a plurality of friction fit structure protruding from the side wall, such that the heat dissipation device inserted in the space can be secured to the protection structure. The friction fit structure includes a plurality of ribs. Preferably, the top edge of the side wall further includes a flange. The heat dissipation device includes a substrate, a plurality of fins projecting from a first surface of the substrate, and the thermal conducting medium attached to a second surface of the substrate. The bottom surface is conformal to the substrate. The side wall has a height lower than the height of the fins. In other embodiment, the side wall is level with the tips of the fins. The protection structure further comprises a lid to seal the heat dissipation device within the protection structure. 
   These and other objectives of the present invention will become obvious to those of ordinary skill in the art after reading the following detailed description of preferred embodiments. 
   It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These, as well as other features of the present invention, will become apparent upon reference to the drawings wherein: 
       FIG. 1  shows a perspective view of a protection structure according to a first embodiment of the present invention; 
       FIG. 2  shows an exploded view of the protection structure applied to a heat dissipation device; 
       FIG. 3  shows a perspective view of the assembly of the protection structure and the heat dissipation device; 
       FIG. 4  shows a cross sectional view of the assembly; 
       FIG. 5  shows an exploded view of a protection structure applied to a heat dissipation device according to a second embodiment of the present invention; 
       FIG. 6  shows a cross sectional view of the assembly as shown in  FIG. 5 ; 
       FIG. 7  shows a cross sectional view of an assembly of a protection structure and a heat dissipation device according to a third embodiment of the present invention; and 
       FIG. 8  shows a perspective view of a protection device according to a fourth embodiment of the present invention; and 
       FIG. 9  shows a cross sectional view of the protection device as shown in  FIG. 8  applied to a heat dissipation device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings wherein the showings are for purpose of illustrating preferred embodiments of the present invention only, and not for purposes of limiting the same. 
   A perspective view of a first embodiment of the protection structure is illustrated as  FIG. 1 , an exploded view the protection structure applied to a heat dissipation device is shown in  FIG. 2 , and  FIG. 3  illustrates the perspective view of the assembly of the protection structure and the heat dissipation device.  FIG. 4  shows the cross sectional view of the assembly. As shown, a heat dissipation device  2  is coated with a thermal conducting medium  20  such as a thermal conductive paste, and the protection structure  1  is used to cover and protect the thermal conducting medium  20  from being exposed to dust or contamination. 
   As shown in  FIGS. 1 to 4 , the protection structure  1  includes a bottom surface  10 , a continuous side wall  11  extending substantially perpendicularly from the periphery of the bottom surface  10 , and at least two contact portions  12  protruding inwardly from the bottom surface  10 . 
   When the protection structure  1  is applied to the heat dissipation device  2 , the bottom surface  10  is on top of the thermal conducting medium  20 . As shown, the heat dissipation device  2  includes a heat sink formed by aluminum extrusion, for example. The heat sink includes a substrate  21  and a plurality of fins  22  formed on a top surface of the substrate  21 . In this embodiment, the thermal conducting medium  20  is coated on the bottom surface of the substrate  21 . Preferably, the contact portions  12  are spaced from each other to form a space larger than the surface area of the thermal conducting medium  20 . 
   The continuous side wall  11  includes a plurality of side surfaces  110 . Depending on the shape of the bottom surface  10 , the arrangement of the side surfaces  110  may be altered. In the embodiment as shown in  FIGS. 1 to 4 , the bottom surface  10  has a rectangular shape, such that four side surfaces  110  construct the continuous side wall  11  in the example. When the bottom surface  10  is circular, only one side surface  110  is required. The bottom surface  10  and the side wall  11  forms a space  13  allowing a portion of the substrate  21  to be inserted therein. Preferably, the bottom surface  10  is conformal to the substrate  21 . 
   When the substrate  21  is partially inserted in the space  13  of the protection structure  1 , the contact portions  12  prevent the bottom surface  10  from contacting with and pressurizing against the thermal conducting medium  20 . In the example as shown in  FIG. 4 , the contact portions  12  include four semi-spherical protrusions. By the contact portions  12 , the substrate  21  is distant from the bottom surface  10  by a space  130  when the substrate  21  is inserted in the protection structure  1 ; and therefore, the thermal conducting medium  20  will not be damaged by the direct contact with the bottom surface  10 . 
   In addition, the top edge of the continuous side wall  11  includes a flange  111  extend outwardly from the space  130 . The flange  111  increases the structure strength and prevents the protection structure  1  from distortion. Further, it provides the convenience of inserting the substrate  21  into the space  130 . 
     FIGS. 5 and 6  shows a modification of the first embodiment of the protection structure  10 . In this embodiment, the side wall  11  extends longer to cover the full height of the heat dissipation device  2 , and the contact portions  12  includes a pair of protruding ridges formed the bottom surface  10 . In addition to the contact portions  12 , a pair of ridges protrudes inwardly from the side surfaces  110  to serve as fitting elements  112 . Thereby, the protection structure  10  can secure the heat dissipation device  1  therein by friction fit. As shown, the tips of the fins  22  are level with the top edge of the side wall  11 , and the protection structure  1  encloses the heat dissipation device  2  therein to be advantageous to package process. 
     FIG. 7  shows a third embodiment of the protection structure  1 , which is a modification of the second embodiment. As shown, a lid  14  is added to cover the open end of the protection structure  1 , such that the heat dissipation device  2  is sealed in the protection structure  1 . The protection structure  1  thus serves as a package of the heat dissipation device  2  as well. 
     FIG. 8  illustrates the perspective view of a protection structure in a fourth embodiment of the present invention, and  FIG. 9  shows a cross sectional view of the assembly of the protection structure and a heat dissipation device. As shown, the heat dissipation device  2 ′ includes a substrate  21 ′ and a stack of fins  22 ′ attached on the substrate  21 ′. The substrate  21 ′ further includes a plurality of resilient fastening members  23  penetrating through the substrate  21 ′. 
   The protection structure  1  includes a bottom surface  10 , a pair of side surfaces  110 , and a pair of elongate ridges  114  protruding from the bottom surface  10 . As shown, the elongate ridges  114  extending from one edge to the other of the bottom surface  10  and are parallel to the side surfaces  110 . Preferably, the height of the side surfaces  110  is higher than that of the ridges  12 , and the space  13  formed between the side surfaces  110  is slightly larger than that of the substrate  21 ′. Therefore, the heat dissipation device  2 ′ can be partially disposed in the space  13 . The lower portion of the space  13  is divided into three parts, including the central portion  130  between the ridges  12  and the side portions  131  between the ridges  12  and the side surfaces  110 . When the heat dissipation device  2 ′ is inserted in the space  13 , the protruding ridges  12  serves as supporting arms of the substrate  21 ′. Each of the protruding ridges  12  includes a side wall  114  facing the side surface  110 , a side wall  113  facing the side wall  113  of the other ridge  12 , and a top wall  112 . The top wall  112  is in direct contact with the substrate  21 ′ when the heat dissipation device  1  is inserted in the space  13 . Further, the distance between the ridges  12 , that is, the dimension of the space  130  is preferably larger than the dimension (width or length) of the thermal conducting medium  20 , such that the thermal conducting medium  20 , while being covered and protected by the protection structure  1 , is not in contact with any structure or element. The spaces  131  allow the fastening members  23  to insert therein. 
   This disclosure provides exemplary embodiments of the present invention. The scope of this disclosure is not limited by these exemplary embodiments. Numerous variations, whether explicitly provided for by the specification or implied by the specification, such as variations in shape, structure, dimension, type of material or manufacturing process may be implemented by one of skill in the art in view of this disclosure.