Patent Publication Number: US-2007107880-A1

Title: Heat sink structure

Description:
FIELD OF THE INVENTION  
      The invention relates to a heat sink structure, which is disposed in CPU of electronic products to absorb and conduct the dissipated heat thereof.  
     BACKGROUND OF THE INVENTION  
      As shown in  FIG. 1 , what Taiwan Patent Application No. 94130233 discloses is a heat sink device containing a cooling fan  50  and a heat sink  21 . The heat sink  21  directly contacts with a heating element  81  to absorb the heat therefrom. The cooling fan  50  is disposed on the heat sink  21  to dissipate heat.  
      The heat sink  21  contains a central heat conducting body  22 . A plurality of cooling fins  23  extend from the periphery of the central heat conducting body  22 . The central heat conducting body  22  has an hole penetrating through one side, and the opening of the hole is sealed by a cover plate  24  so as to form an fully sealed hollow chamber  221 . The chamber  221  is filled with a cooling liquid and disposed an agitator  25 . The locations corresponding to the agitator  25  and a rotor of the cooling fan are disposed the permeability components  251  &amp;  54  having the magnetic attraction and mutual traction therebetween so that the agitator  25  can synchronously rotate with the rotor  53 .  
      As a result, when the agitator  25  synchronously rotate with the rotor  53 , the cooling liquid filled in the chamber  221  is thus agitated such that the cooling liquid carrying heat becomes a dynamic hot liquid immediately and uniformly diffusing and conducting the heat to each cooling fin to facilitate the heat dissipation of the cooling fan  23 .  
      Accordingly, the heat conduction speed of the heat sink  21  is critical to the heat transfer performance of the entire heat dissipation module. As the cooling liquid in the chamber  221  absorbs the heat of a heating element  81  in accordance with the heat transfer performance of the heat sink  21 , when the heat transfer speed is low, there is no way for the agitator  25  to perform; the agitator can only outperform in terms of heat dissipation effect when the heat transfer speed is high. Based on the spirit striking for perfection, the present invention particularly targets at the heat transfer speed issue to further improve so as to attain faster and more efficient heat dissipation effect.  
     SUMMARY OF THE INVENTION  
      In view of this, the invention thus provides a heat sink structure. The heat sink includes a central heat conducting body that has a plurality of cooling fins extending from the periphery of the central conducting body, through holes therein penetrating two side, and a cover plate and a bottom plate sealing the openings of the through holes, in formation of a hollow chamber. The chamber is filled with a cooling liquid and is disposed an agitator. The agitator and a rotor of a cooling fan are disposed permeability components thereon magnetically attracting and mutually dragging at the corresponding locations so that the agitator synchronously rotates with the rotor.  
      Because the bottom plate can be easily replaced with the material with higher thermo-conductivity coefficient, it can rapidly absorb the heat of the heating element and swiftly conduct the heat to the cooling liquid.  
      Together with the aid of the fin design, when the agitator agitates the cooling liquid, on the one hand those fins can increase the contact area of the fins and the cooling liquid, and on the other hand the turbulent flow mixing effect of the cooling liquid can be increased, so that the absorbed heat can be diffused in a fast and uniform way, providing an efficient heat dissipation effect. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic view showing the cross-sectional view of the conventional structure;  
       FIG. 2  is an exploded schematic view showing the first preferred embodiment of the present invention;  
       FIG. 3  is a cross-sectional view showing the first preferred embodiment of the present invention;  
       FIG. 4  is an exploded view showing the second schematic view of the present invention;  
       FIG. 5  is a cross-sectional schematic view showing the second preferred embodiment of the present invention;  
       FIG. 6  is a cross-sectional view showing the third preferred embodiment of the present invention; and  
       FIG. 7  is a cross-sectional view showing the fourth preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      The invention relates to a heat sink structure, wherein the central heat conducting body of the heat sink has through-holes penetrating two sides thereof, and the openings of both sides are covered with a cover plate and a bottom plate respectively so as to form an absolutely sealed hollow chamber. The bottom plate can be manufactured with the material with a higher thermo-conductivity coefficient so that the heat generated by the heating element can be swiftly absorbed to facilitate the heat dissipation of the cooling fan.  
      Here are some preferred embodiments as follows to illustrate the respective positions of the parts in the present invention.  
      Please also refer to  FIG. 2  and  FIG. 3 . The heat sink  21  has a central heat conducting body  22 . A plurality of cooling fins  23  extend from the periphery of the central heat conducting body  22 . The central heat conducting body  22  has a through hole, which penetrating two sides. The openings on the two sides are covered by a cover plate  24  and a bottom plate  27  respectively. The engagement means pertains to one fastened by screw (as shown in  FIG. 3 ) or rivet, or by gluing capable of achieving the sealing effect.  
      The sides of the central heat conducting body  22  corresponding the cover plate  24  and the bottom plate  27  have an annular slot  222  filled with an O ring  223  so as to make the chamber  223  a fully sealed space.  
      The chamber  221  is filled with a cooling liquid and disposed an agitator  25 . There is a cooling fan  50  on top of the heat sink  21 . The permeability components  251 ,  54  where are disposed on the corresponding positions of the agitator  25  and the rotor  53  of the cooling fan  50  magnetically attract and mutually drag so that the agitator  25  synchronously rotates with the rotor  53 .  
      The design of the invention allows the bottom plate  27  to be manufactured with the material easily swapped by those having thermo-conductivity coefficient higher than that of the heat sink  21 , e.g. the material with high thermo-conductivity coefficient like copper, silver and so forth. When the bottom plate  27  is in contact with the heating element  81 , it can absorb and conduct the heat generated by the heating element  81  more quickly and swiftly transfer the heat to be absorbed by the cooling liquid in the chamber  221 .  
      As a consequence, while coupling with the agitator  25  to agitate the cooling liquid, the heat dissipation effect can be even more performed. The cooling liquid absorbing heat becomes a dynamic hot liquid and immediately and uniformly diffuse and conduct heat to each cooling fin to facilitate the heat dissipation of the cooling fan  50 , attaining a faster and more efficient cooling effect.  
      Besides, also as shown in  FIG. 4  and  FIG. 5 , one side of the bottom plate  27  facing to the chamber  221  is disposed a plurality of auxiliary fins  271  additionally. These auxiliary fins  271  are a protrusion in form of a circular cylinder, a square cylinder or laminated shape (circular cylinder shown in  FIG. 4  so as to conduct and diffuse the heat of large area to the cooling liquid more quickly.  
      Therefore, when the agitator  25  agitates the cooling liquid, on the one hand, these auxiliary fins  271  increase the contact area with the cooling liquid so as to augment the heat transfer efficiency, on the other hand, the agitated turbulent flow effect of the cooling liquid is enhanced such that the heat absorbed by the cooling liquid can be more swiftly and uniformly conducted to every cooling fin  23  to facilitate the heat dissipation of the cooling fan  50 .  
      Furthermore, when the auxiliary cooling fins are designed with different heights, the cooling liquid collides with the auxiliary cooling fins with different heights. The resulting turbulent flows are all different so as to generate more turbulent flow in the chamber.  
      As shown in  FIG. 6 , the auxiliary cooling fins  272  on the bottom plate  27  are designed in a way having the top height at the center and the progressively decreased heights distributed along either direction from the center so that the cooling liquid collides the orderly distributed auxiliary cooling fins  272  to result in more turbulent flow in the chamber  221 .  
      Also as shown in  FIG. 7 , the auxiliary cooling fins  272  are designed in a way having the top heights on both ends and the progressively decreased heights distributed from both ends to the center so that the cooling liquid forms the turbulent flow between any two of the auxiliary cooling fins so as to swiftly diffuse the heat absorbed by the cooling liquid, providing the optimal cooling effect.  
      In sum, the heat sink designed in the invention facilitates to replace the bottom plate with better heat transfer speed so as to provide better heat transfer and heat diffusion and rapidly carry away the heat generated by the heating element. If the design of the auxiliary fins are combined, on the one hand, the contact area of the cooling liquid are increased, on the other hand, the mixing effect of more turbulent flows are formed so that the heat absorbed by the cooling liquid can be more swiftly and uniformly transferred to every cooling fin. Therefore, the present invention not only has a novelty and a progressiveness, but also has an industry utility.  
      While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the specification, appended claims or figures, which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.