Patent Publication Number: US-2007114006-A1

Title: Heat-dissipating fin assembly for heat sink

Description:
FIELD OF THE INVENTION  
      The present invention generally relates to a heat sink for removing heat from electronic components and particularly to a heat sink comprising a plurality of interlocked fins.  
     DESCRIPTION OF RELATED ART  
      With the continuing development of electronics technology, new electronic components can perform more and more functions. Heat generated by modern electronic components has increased considerably. Measures must be taken to efficiently remove the heat from the electronic components. Typically, a heat sink having great heat conductivity is mounted on the electronic component to remove heat therefrom.  
      A conventional heat sink includes a plurality of fins stacked together. Each of the fins comprises a main body and top and bottom flanges extending perpendicularly from respective top and bottom side edges of the body. Each of the top and bottom flanges defines a pair of locking slots near opposite ends thereof, and comprises a pair of insertion tabs adjacent the locking slots. Each insertion tab of the top flange forms a bulge on a bottom surface thereof, and defines a recess in an upper surface thereof. Each insertion tab of the bottom flange forms a bulge on an upper surface thereof, and defines a recess in a bottom surface thereof. In assembly, the insertion tabs of a rear one of the plates are inserted into the locking slots of an adjacent front one of the plates. The bulges of the insertion tabs of the rear plate are engaged in the recesses of the insertion tabs of the front plate, so that the rear plate is connected to the front plate. Other plates are then attached to the combined rear and front plates in sequence in the same way. The top flanges of the plates commonly define a top surface of the heat sink and the bottom flanges of the plates commonly define a bottom surface of the heat sink.  
      However, a seam exists between the flange of the rear plate and the main body of the front plate, perpendicular to the top and bottom surfaces of the heat sink. When solder paste is applied to the top or bottom surface of the heat sink, the liquid solder paste is prone to flow from one side of the flange to an opposite side of the flange and into the main body of the plate through the seam to form solder droplets on the main body. The solder droplets on the main bodies of the fin plates of the fin assembly affect not only the appearance but also the heat dissipation effectiveness of the heat sink.  
     SUMMARY OF INVENTION  
      A heat-dissipating fin assembly comprises a plurality of individual fin plates arranged side by side. Each fin plate comprises a main body and a pair of flanges extending perpendicularly from opposite top and bottom sides of the main body. Each flange comprises a first plane extending from the main body and a second plane extending from and parallel to the first plane. The second plane comprises a pair of engaging projections extending from two ends thereof. The second plane of a rear one of the fin plates engagingly covers the first plane of an adjacent front one of the fin plates, and the rear and front fin plates are interlocked by the engaging projections of the second plane of the rear fin plate bent to respectively engage two ends of the first plane of the front fin plate.  
      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 DRAWING  
       FIG. 1  is an isometric view of a heat-dissipating fin assembly in accordance with a preferred embodiment of the present invention, the assembly comprising a plurality of fin plates;  
       FIG. 2  is a view similar to  FIG. 1  with one fin plate separated from the others to more clearly show the structure of the fin plate;  
       FIG. 3  is an enlarged view of a circled part III of  FIG. 2 ;  
       FIG. 4  is a side view of the separate fin plate of  FIG. 2 ; and  
       FIG. 5  is an isometric view of a heat-dissipating fin assembly in accordance with another embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIGS. 1-4 , a heat-dissipating fin assembly  1  in accordance with a preferred embodiment of the present invention comprises a plurality of individual fin plates  10  arranged side by side.  
      Each fin plate  10  is made of highly thermal conductive material such as aluminum or copper, and is formed by stamping to have a main body  14 . A pair of flanges  16  extends perpendicularly from opposite top and bottom edges of the main body  14  respectively. Each flange  16  comprises a first plane  162  extending perpendicularly from each of the top and bottom edges of the main body  14  and a second plane  164  extending from a free edge of the first plane  162  and parallel to the first plane  162 . The first plane  162  has a same breadth with the second plane  164 , as viewed from a lateral side of the fin assembly  1 . A pair of engaging projections  166  is formed at opposite ends of the second plane  164 . The second plane  164  has a length larger than that of the first plane  162  as viewed from a front side of the fin assembly  1  before the engaging projections  166  are bent to engage with the first plane  162  of a neighboring front fin plate  10 . A connecting portion  163  is formed between the first and second planes  162 ,  164  to connect the first and second planes  162 ,  164  together. Seeing  FIG. 4 , the connecting portion  163  is arc-shaped as viewed from the lateral side view of the fin plate  10 . The connecting portion  163  extends outwardly from the first plane  162  toward the second plane  164  to make the first and second planes  162 ,  164  on different levels. The two planes  162 ,  164  are spaced from each other a distance substantially the same as a thickness of the fin plate  10  for forming the fin plate  10 .  
      Referring to  FIG. 2 , in assembling the fin plates  10  to form the heat-dissipating fin assembly  1 , the second plane  164  of a rear one of the fin plates  10  is engagingly received on an outer surface of the first plane  162  of an adjacent front one of the fin plates  10 , so that the outer surface of the first plane  162  of the front fin plate  10  is covered by the second plane  164  of the rear fin plate  10 . An Inner surface of the second plane  164  of the rear fin plate  10  is tightly attached on an outer surface of the first plane  162  of the front fin plate  10 . All second planes  164  disposed on the first planes  162  are arranged at a same level to form flat top and bottom surfaces at top and bottom of the heat-dissipating fin assembly  1 , respectively. The engaging projections  166  of the second plane  164  of the rear fin plate  10  are bent inwardly respectively from two ends of the second plane  164  to enclose and tightly engage two ends of the first plane  162  of the front fin plate  10 , respectively. The engaging projections  166  of the rear fin plate  10  are used to avoid moving of the front fin plate  10  along a direction toward lateral sides of the fin assembly  1 . All second planes  164  of the flanges  16  form a top and a bottom of the heat-dissipating fin assembly  1 .  
      In the preferred embodiment of the present invention, a seam (not labeled) exists between a front edge of the second plane  164  of the rear fin plate  10  and an outer surface of the connecting portion  163  of the front fin plate  10 . When solder paste is applied to the top or bottom of the heat-dissipating fin assembly  1 , some of the liquid solder paste is received in the seams. Since the second planes  164  are tightly engaged with the first planes  162 , the liquid solder plate is prevented to flow from the seams to the main bodies  14  of the fin plates  10  to form solder droplets thereon.  
      Referring to  FIG. 5 , in another embodiment of the present invention the heat-dissipating fin assembly  1 ′ comprises a base  12  and the flanges  16  of the bottom of the fin plates  10  are attached on the base  12 .  
      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 hereinbefore described merely being preferred or exemplary embodiments of the invention.