Abstract:
A heat sink includes a plurality of fins parallel to each other. The fins include a top portion having a flange. The opposite ends of each flange are rounded. Two rounded corners are located below the plane defined by the flange.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to heat sinks, particularly to a heat sink for dissipating heat from an electronic device. 
         [0003]    2. Description of Related Art 
         [0004]    Computers are continuing to rapidly develop. Electronic devices in computers, such as central processing units (CPUs), generate a lot of heat during normal operation, which can deteriorate their operational stability, and damages associated electronic devices. Thus, the heat must be removed quickly to ensure normal operation of the CPU. A heat sink is often provided on the CPU to remove heat therefrom. 
         [0005]    Referring to  FIG. 5 , a heat sink  10 ′ according to the prior art includes several U-shaped heat pipes  11 ′ and a plurality of parallel fins  12 ′. The fins  12 ′ are bent towards a same direction and are soldered together. The thickness of each fin  12 ′ is about 0.3˜0.4 mm. Furthermore, corners of each fin  12 ′ are formed in right angle, which is dangerous to lacerate users&#39; fingers. For example, right angles  121 ′,  122 ′ of the fins  12 ′ pose the danger to people who are using the heat sink  10 ′. 
       SUMMARY 
       [0006]    A heat sink includes a plurality of fins parallel to each other. The fins include a top portion having a flange. The opposite ends of each flange are rounded. Two rounded corners are located below the plane defined by the flange. 
         [0007]    Other advantages and novel features will be drawn from the following detailed description of preferred embodiments with attached drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an isometric view of a heat sink of in accordance with an exemplary embodiment of the present invention; 
           [0009]      FIG. 2  is an enlarged view of an encircled portion  11  of  FIG. 1 ; 
           [0010]      FIG. 3  is another isometric view of  FIG. 1 ; 
           [0011]      FIG. 4  is a view of the heat sink assembled on a motherboard; and 
           [0012]      FIG. 5  is an isometric view of a heat sink of a prior art. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIG. 1 , a heat sink in accordance with a preferred embodiment of the present invention includes a base  10 , a plurality of parallel fins  20  on the base  10 , and a pair of heat pipes  30  extending through the fins  20  to transfer heat from the base  10  to the fins  20 . 
         [0014]    Referring to  FIG. 2  and  FIG. 3 , four screws  11  are mounted on four corners of the base  10  respectively. A heat dissipating portion  12  is formed on the bottom of the base  10 . An area of the heat dissipating portion  12  is approximately equal to an area of a CPU. Two semicircular channels (not shown) are defined in the heat dissipating portion  12  corresponding to two heat pipes  30 . 
         [0015]    Each fin  20  is a thin metallic plate extending perpendicularly up from the base  10 . Two circular channels  31  and two semicircular channels  32  are defined in each fin  20  corresponding to two heat pipes  30 . The top of each fin  20  is bent towards a same direction to form a flange  21 . Opposite ends of each flange  21  are cut to form first rounded corners  22 . The top corners of each fin  20  are cut to form second rounded corners  23  adjacent to the flanges  21 . The length of the flange  21  is shorter than the length of the fin  20 . Wings  27  are projected from a middle portion at each end of the fins  20 . Top and bottom corners of each wing  27  are cut to form third rounded corners  24 . When the heat sink is used, the first, second, third rounded corners  22 ,  23 ,  24  are safer to handle than the right-angle corners of the prior art, thus protecting users&#39; fingers from being cut. 
         [0016]    Each heat pipe  30  is approximately U-shaped. The heat pipe  30  is sealed container, wick structure attached at inner surface and working fluid and its vapor inside. The heat pipe  30  extends through the semicircular channel of the heat dissipating portion  12 , the semicircular channel of the fin  20  and the circular channel  31  of the fin  20 . The heat pipe  30  transfers heat from the base  10  to the fins  20  for dissipating heat fast. 
         [0017]    Referring to  FIG. 4 , when used, the heat sink is mounted on a CPU  51  of a motherboard  50 . The heat dissipating portion  12  of the heat sink contacts with the CPU  51 . The heat dissipating portion  12  transfers heat produced by the CPU  51  to the fins  20  via the heat pipes  30 . Thereby, the temperature of the CPU  51  is reduced. 
         [0018]    It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of preferred embodiments, together with details of the structures and functions of the preferred embodiments, 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.