Patent Publication Number: US-2007103871-A1

Title: Heat dissipation module

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims the priority benefit of Taiwan application serial no. 94138935, filed on Nov. 7, 2005. All disclosure of the Taiwan application is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a heat dissipation module. More particularly, the present invention relates to a heat dissipation module with fins having at least a bent portion.  
      2. Description of the Related Art  
      With the continuous improvement in electronic technologies in recent years, the computing speed of the electronic devices used inside the computer has also been constantly increased. As the power rating of various electronic elements continues to increase, the heat associated with the operation also increases substantially. To prevent an electronic device from reaching an excessively high temperature that may slow down the device or even cause a temporary or permanent malfunction of the device, a cooling system with enough capacity to maintain a constant operating temperature must be deployed. The most common method of dissipating the heat produced by an electronic device is to mount a heat dissipation module over the electronic device. Thus, the heat produced by the electronic device as well as any heat accumulated around the device can be carried away through conduction or convection. In the following, the method of dissipating the heat generated by an electronic device is described in more detail with a diagram.  
       FIG. 1  is a perspective view of a conventional heat dissipation module. As shown in  FIG. 1 , the method of dissipating heat from an electronic device  130  is to mount a heat dissipation module  100  over it. The electronic device  130  may be a central processing unit (CPU) or other electronic component that generates lots of heat. The heat dissipation module  100  includes a heat sink  110  and a fan  120 , wherein the heat sink  110  has a cooling plate  112  and a plurality of flat cooling fins  114  disposed in parallel to each other on the surface of the cooling plate  112 . The bottom surface of the cooling plate  112  is attached to a surface of the electronic device  130 . The electric fan  120  is disposed on top of the heat sink  110  with the air outlet facing down.  
      The heat produced by the electronic device  130  can conduct to the cooling fins  114  via the cooling plate  112 . Then, the fan  120  forces air to blow down to the cooling fins  114  of the heat sink  110  and thus the hot air flows out via the sides so that a convection current with the air is established to carry the heat to the surrounding atmosphere, thereby lowering the temperature of the electronic device  130 .  
      As shown in  FIG. 1 , to increase the heat dissipating capacity of a conventional heat dissipation module  100 , the number of cooling fins  114  in the heat sink  110  must be increased so as to increase the heat dissipating area. However, the number of cooling fins  114  that can be put on the cooling plate  112  is restricted. Furthermore, the heat dissipating area that can be provided by a flat cooling fin  114  is quite limited. In addition, the density of cooling fins  114  will increase if more cooling fins  114  are added to the heat sink  110 . The narrower separation between the cooling fins  114  will impede the flow of air through the fins  114  and reduce the heat dissipating capacity of the convective current.  
     SUMMARY OF THE INVENTION  
      Accordingly, at least one objective of the present invention is to provide a heat dissipation module with a larger heat dissipating area for producing a better cooling effect.  
      To achieve this and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a heat dissipation module. The heat dissipation module comprises a fixing part and a plurality of heat dissipation fins. The heat dissipation fins are fastened to the fixing part. Each heat dissipation fin has at least a bent portion. The bent portion connects to a first portion and a second portion. Furthermore, the first portion and the second portion are not located on the edge of the heat dissipation fin.  
      In one embodiment of the present invention, the first portion and the second portion can be a plane surface or a curve surface and the bent portion is formed by bending.  
      In one embodiment of the present invention, the bent portion can be a turning comer of the heat dissipation fins and the bent portion can have at least a slant surface.  
      In one embodiment of the present invention, the aforementioned fixing part includes a bottom block and a plurality of supporting tubes. The supporting tubes not only connect with the bottom block, but also pass through and fix to the heat dissipation fins. Furthermore, the supporting tubes may pass through the sides of the bottom block and extend upwards, for example.  
      In one embodiment of the present invention, the aforementioned heat dissipation fins may further include a plurality of first heat dissipation fins and a plurality of second heat dissipation fins. The first heat dissipation fins are stacked on top of each other with a gap maintained between each other and located on one side above the bottom block. Similarly, the second heat dissipation fins are stacked on top of each other with a gap maintained between each other and located the other side above the bottom block.  
      In one embodiment of the present invention, the first heat dissipation fins can be sequentially latched to each other. Similarly, the second dissipation fins can also be sequentially latched to each other.  
      In one embodiment of the present invention, the bent portion can connect to two plane surface or two curve surface. In addition, the bent portion can be one corner of the heat dissipation fin.  
      In one embodiment of the present invention, the heat dissipation module may further include a fan disposed above the bottom block and located between the first heat dissipation fins and the second heat dissipation fins. The fan can be an axial fan for driving air from the first heat dissipation fins toward the second heat dissipation fins.  
      In the present invention, the heat dissipation module uses heat dissipation fins having bent portions. Hence, the heat dissipation area is larger than the conventional flat dissipation fins. Thus, without increasing the number of heat dissipation fins and the fin density, a better cooling effect can be achieved.  
      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  
      The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,  
       FIG. 1  is a perspective view of a conventional heat dissipation module.  
       FIG. 2  is a perspective view of a heat dissipation module according to one embodiment of the present invention.  
       FIG. 3  is a side view of a heat dissipation module according to one embodiment of the present invention.  
       FIGS. 4A and 4B  are respectively the perspective and side view of one heat dissipation fin according to the present invention.  
       FIG. 5  is a side view of a heat dissipation module according to another embodiment of the present invention.  
       FIG. 6  is another side view of the heat dissipation module shown in  FIG. 5 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.  
       FIG. 2  is a perspective view of a heat dissipation module according to one embodiment of the present invention.  FIG. 3  is a side view of a heat dissipation module according to one embodiment of the present invention. As shown in  FIG. 2 , the heat dissipation module  200  includes a fixing part  210  and a plurality of heat dissipation fins  220 . The heat dissipation fins  220  are fastened to the fixing part  210 . Each heat dissipation fin  220  has at least a bent portion  220   a . The fixing part  210  may include a bottom block  210   a  and a plurality of supporting tubes  210   b  connected to the bottom block  210   a . The supporting tubes pass through and clamp the heat dissipation fins  220  together. In the present embodiment, the heat dissipation fins  220  are fastened to the fixing part  210  by soldering to the supporting tubes  210   b . Obviously, other methods (for example, a tight interference between the two) can be used to fasten the heat dissipation fins  220  to the fixing part  210 . Hence, this should by no means limit the scope of the present invention.  
      In addition, as shown in  FIG. 2 , the supporting tubes  210   b  of the heat dissipation module  200  may pass through the sides of the bottom block  210   a  and extend upwardly to further pass through and fasten the heat dissipation fins  220 . More specifically, the bottom block  210   a  may comprise two plate-like copper blocks stacked over each other. The two copper blocks together form a clamp that grips the mid-section of the supporting tubes  210 .  
      As shown in  FIG. 3 , the heat dissipation fins  220  in the present, embodiment include a plurality of first heat dissipation fins  222  and a plurality of second heat dissipation fins  224 . The first heat dissipation. fins  222  are stacked over each other with a gap maintained between them and disposed on one side of the bottom block  210   a . Similarly, the second heat dissipation fins  224  are stacked over each other with a gap maintained between them and disposed on the other side of the bottom block  210   a . In other words, the first heat dissipation fins  222  are disposed on one side above the bottom block  210   a  and the second heat dissipation fins  224  are disposed on the other side above the bottom block  210   a . The first heat dissipation fins  222  and the second heat dissipation fins  224  are fixed by the supporting tubes  210   b  extending upwardly from the respective sides of the bottom block  210   a  and passing through them. Furthermore, the first heat dissipation fins  222  slide into the supporting tubes  210   b  and latch to each other in sequence. Similarly, the second heat dissipation fins  224  also slide into the supporting tubes  210   b  and latch to each other in sequence. The first heat dissipation fins  222  and the second heat dissipation fins  224  are soldered to the supporting tubes  210   b . Alternatively, the heat dissipation fins  222  and  224  are passed into the supporting tubes  210   b  one after another and fixed in position through a tight tolerance. Obviously, the heat dissipation fins can be assembled together through some other means as the scope of the present invention is not limited as such.  
      It should be noted that the each heat dissipation fin in the heat dissipation module of the preferred embodiment of the present invention has at least a bent portion. The bent portion connects to a first portion and a second portion. Furthermore, the first portion and the second portion are not located on the edge of the heat dissipation fins. In the following, the structure of a typical heat dissipation fin is explained in more detail.  
       FIGS. 4A and 4B  are respectively the perspective and side view of one heat dissipation fin according to the present invention. As shown in  FIGS. 4A and 4B , the heat dissipation fin  320  includes four bent portions  320   a ,  320   b ,  320   c ,  320   d  and a first portion  320   e , a second portion  320   f , a third portion  320   g , a fourth portion  320   h , a fifth portion  320   i . The bent portions  320   a ,  320   b ,  320   c ,  320   d  connect to the first portion  320   e  and the second portion  320   f , the second portion  320   f  and the third portion  320   g , the third portion  320   g  and the fourth portion  320   h  and the fourth portion  320   h  and the fifth portion  320   i  respectively. Furthermore, the bent portions  320   a ,  320   b ,  320   c ,  320   d  are not located on the edge of the heat dissipation fin  320 . The first portion  320   e , the second portion  320   f , the third portion  320   g , the fourth portion  320   h  and the fifth portion  320   i  are plane surfaces or curve surfaces with the bent portions  320   a ,  320   b ,  320   c  and  320   d  connecting them through bending. In other words, the heat dissipation fins  320  may be constructed using multiple sections of plane surfaces or curve surfaces with the bent portions  320   a ,  320   b ,  320   c ,  320   d  serving as a connection at the junctions between the plane surfaces or the curve surfaces. In addition, the bent portions  320   a ,  320   b ,  320   c  and  320   d  also provide some corner turning in the shape of the heat dissipation fin  320 . Furthermore, each of these bent portions  320   a ,  320   b ,  320   c  and  320   d  can have at least a slant surface. By incorporating the bent portions  320   a ,  320   b ,  320   c ,  320   d  in the design of the heat dissipation fin  320 , the surface area of the heat dissipation fin  320  increases significantly compared to the conventional flat fin.  
      In addition, the heat dissipation fin  320  can have a plurality of plug holes  320   j  formed therein that allows the supporting tubes  210   b  to penetrate and fix a number of heat dissipation fins  320  to the fixing part  210  of the heat dissipation module  200 .  
      In the present invention, because the heat dissipation fins have a plurality of bent portions for joining plane surfaces or curved surfaces together, the total heat dissipation area is greater than the conventional heat sink with flat heat dissipation fins. Therefore, without increasing the number of fins or the fin density, the present invention can increase the heat dissipation area so that the heat exchange capacity of the heat dissipation module is increased. Ultimately, the heat dissipation module can provide a better cooling effect.  
       FIG. 5  is a side view of a heat dissipation module according to another embodiment of the present invention.  FIG. 6  is another side view of the heat dissipation module shown in  FIG. 5 . As shown in  FIGS. 5 and 6 , the heat dissipation module  400  is similar to the heat dissipation module  200  in  FIG. 2 . The only difference is that an electric fan  430  is disposed in the heat dissipation module  400  above the bottom block  210   a  between the first heat dissipation fins  222  and the second heat dissipation fins  224 . The fan  430  is an axial fan, for example, for driving air in the fin gaps  222   a  of the first heat dissipation fins  222  toward the fin gaps  224   a  of the second heat dissipation fins  224 . In other words, the fan  430  can enhance the flow of air from the fin gaps  222   a  to the fin gaps  224   a  (the arrow in  FIG. 6  shows the direction of movement of an air current). Therefore, the cooling capacity of the heat dissipation module  400  is further increased.  
      It should be noted that the heat dissipation fins have slant surfaces due to the presence of bent portions. These slant surfaces can be designed to match the shape of the fan blades and the air stream so that the cooling capacity is further increased.  
      In summary, the heat dissipation module of the present invention uses heat dissipation fins with bent portions so that the slant surfaces at the bents can increase the overall heat dissipation area. In other words, the heat dissipation module can provide a better cooling performance without increasing the number of heat dissipation fins and the fin density.  
      It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.