Patent Publication Number: US-2009231814-A1

Title: Protective cap for thermal grease

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to heat-dissipating devices, and more particularly, to a protective cap for thermal grease of a heat sink. 
     2. Description of the Related Art 
     A conventional protective cap for thermal grease of a heat sink as disclosed in U.S. Pat. No. 6,049,458 includes a cover having a cavity and adhesively mounted to a bottom side of the heat sink. Thermal grease on the heat sink is surrounded in the cavity of the cover to be protected and to avoid dust. 
     Because the conventional protective cap is adhesively mounted to the heat sink, however, the cover may accidentally disengage from the heat sink due to deficient adhesiveness. In addition, after the cover is removed from the heat sink, there may be some unnecessary adhesive remaining on the bottom side of the heat sink. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a protective cap, which protects thermal grease disposed on a bottom side of a heat sink. 
     The secondary objective of the present invention is to provide a protective cap, which can be fixed to a bottom side of the heat sink without adhesive. 
     The foregoing objectives of the present invention are attained by the protective cap composed of a sheet member. The sheet member includes a main concavity recessed downward from a center thereof; and four corner concavities recessed downward from four corners located a periphery of the main concavity respectively. Each of at least two of the corner concavities has an interference hole formed at a bottom sidewall thereof. The interference holes are to be interference fit with respective screw bolts located at the bottom side of the heat sink to fasten the sheet member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred embodiment of the present invention. 
         FIG. 2  is a perspective view of the preferred embodiment of the present invention that is upside-down. 
         FIG. 3  is a perspective view of the preferred embodiment of the present invention that is being combined with a heat sink. 
         FIG. 4  is a perspective view of the preferred embodiment of the present invention combined with the heat sink. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1-2 , a protective cap  10  for thermal grease of a heat sink in accordance with a preferred embodiment of the present invention is composed of a sheet member  11 . 
     The sheet member  11  includes a main concavity  12  recessed downward from a center thereof, four corner concavities  14  recessed downward from four corners located a periphery of the main concavity  12 , four intercommunication concavities  16  recessed downward therefrom and located between the main concavity  12  and the corner concavities  14  respectively, and a plurality of protective ridges  13  protruding upward from a bottom side of the main concavity  12 . An interference hole  15  is formed at a bottom sidewall of each of at least two corner concavities  14 . The at least two interference holes  15  are located at diagonal ones of the corner concavities  14  respectively. Each of the intercommunication concavities  16  is less deep than the corner concavity  14  and than the main concavity  12 . The protective ridges  13  are located at least two sides in the main concavity  12 . In this embodiment, the protective ridges  13  are located at four sides in the main concavity  12 . A top side of each of the protective ridges  13  is as high as a bottom side of the intercommunication concavity  16 . 
     Referring to  FIGS. 3 and 4  in view of  FIG. 1 , the protective cap  10  of the present invention is in coordination with a heat sink  21 . The heat sink  21  includes a heat-dissipating plate  22  at a bottom side thereof, a rectangular layer of thermal grease  23  disposed on a central part of a bottom side of the heat-dissipating plate  22 , and four extension parts  24  extending outward from four corners of the heat-dissipating plate  22  respectively. A screw bolt  26  is inserted through each of respective distal ends of the extension parts  24 . Each of the screw bolts  26  has a thread  27  at a distal end thereof. After the protective cap  10  is covered to the bottom side of the heat-dissipating plate  22 , the screw bolts  26  are located in the corner concavities  14  and inserted through the interference holes  15  respectively, the threads  27  interfering with the interference holes  15  respectively, such that the protective cap  10  is fixed to the heat sink  21  by interference fit. 
     After the protective cap  10  is fixed to the heat sink  21 , the protective ridges  13  are stopped against the bottom side of the heat-dissipating plate  22 . Because the protective ridges  13  are located at lateral sides of the heat-dissipating plate  22 , they will not touch the thermal grease  23  and the intercommunication concavities  16  are stopped against respective bottom sides of the extension parts  24 . In the meantime, the bottom sides of the extension parts  24  are partially covered by the intercommunication concavities  16  and the bottom side of the heat-dissipating plate  22  is also partially covered by the main concavity  12 . 
     When the protective cap  10  of the present invention is mounted to the heat sink  21 , the thermal grease  23  can be protected in the main concavity  12 . The protective cap  10  is fixed to the heat sink  21  in such a way that the screw bolts  26  interfere with the interference holes  15  respectively. The protective ridges  13  keep the space in the main concavity  12  intact and prevent the deformed structure incurred by an external force from damage to the thermal grease  23 . 
     In conclusion, the present invention includes the following advantages. 
     1. The protective cap of the present invention can be covered to the bottom side of the heat sink to provide good protection for the thermal grease. 
     2. The protective cap of the present invention is fixed to the bottom side of the heat sink by the interference fit between the screw bolts and the interference holes without any adhesive, such that it prevents the bottom side of the heat sink from unnecessary remnant substance. 
     Although the present invention has been described with respect to a specific preferred embodiment thereof, it is no way limited to the details of the illustrated structures but changes and modifications may be made within the scope of the appended claims.