Patent Publication Number: US-2006011329-A1

Title: Heat pipe heat sink with holeless fin module

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates in general to a heat pipe heat sink, and more particularly, to a heat pipe heat sink with a holeless fin module. Because of the holeless arrangement the present invention is much more convenient for manufacturing a heat pipe heat sink. The heat generated by an electrical component can quickly be transferred into the heat pipe and uniformly distributed to each of the heat dissipating fins.  
      Currently, the most common heat dissipation device is a cooling fan which is fixed onto the housing of some piece of electrical equipment. This cooling fan facilitates air circulation by replacing the inner heated air with the cooler outer air. If a system only uses cooling fans to dissipate heat, it may have poor performance though. It may have poor performance because the air brought in from the outside may not always be much cooler than the air in the system&#39;s interior; in the summer the exterior temperature could reach 35 degree C. or more. Therefore, installing more cooling fans is in vain. Moreover, within a system&#39;s housing there is not much extra space that could be used for the installation of extra fans.  
      Another heat dissipating device utilized to remove the heat generated by electrical components is the heat sink, which includes a heat sink base and a fin module mounted on the base. The fin module is mounted on an electrical component via the heat sink base in order to absorb the heat which is generated by the electrical component. The heat absorbed by the fin module is then dissipated into the air. These fins are fabricated from a highly conductive material and formed into distinct sheet elements which are further assembled into a module by some means of assembly.  
      There are many different combinations of the heat dissipating fin module. One of the combinations is the heat pipe and heat dissipating fin combination, as illustrated in  FIG. 1 . The heat dissipating fins are bored through with one or more holes while the heat sink base is bored through with the same number of holes. Further, the heat pipes are forcibly inserted by a machine into the aforementioned holes of the heat dissipating fins and the heat sink base in order to assemble the heat sink. The heat generated by the electrical component is transferred into the heat sink base via heat conduction, and further transferred into the heat pipe and forwarded to the heat dissipating fin module where it is dissipated into the air via heat convection.  
      However, the conventional means of combining the heat dissipating fin module with the heat pipe is through “plugging the heat pipes directly into the holes bored through the heat dissipating fin module by utilizing their difference in diameter.” In other words, the inner diameters of the holes of the heat dissipating fin module are slightly smaller than the exterior diameter of the heat pipe. Such a method is likely to damage or distort the heat dissipation fin module though. It is because of this damage or distortion, which occurs during assembly, that the tight fit between the heat pipe and the fin module is not optimal. To remedy this problem, hot solder is injected to fill the gap between the heat pipe and the fin module. However, remedying the gaps caused by the forcible insertion through the injection of hot solder does not greatly enhance performance. Further, the application of the injection remedy is difficult. Gravity causes the solder to be distributed unequally; the solder collects at the bottom of the gap leaving the top of the gap unfilled. Because there is no solder at the top of the gap, there is no connection at that location between the heat pipe and the fin module to help facilitate heat conductivity.  
      Another structural configuration of the heat pipe and the heat dissipating fin module is disclosed in a Taiwan design patent, No. 506689, a heat dissipating device. This invention includes several heat dissipating plates with one or more holes bored through them. The plates are made of a highly conductive material. There is a circular wall formed around each of the holes. The circular wall has one or more open slots. The heat conducting column, which is made of a highly conductive material, has a rod shape. The heat conducting column is forcibly inserted into the holes of the heat dissipating plates. This configuration has an improved tight fit. However, because the heat conducting column is forcibly inserted into the bored holes, the distortion problem of the heat dissipating plates still exists. The soldering problem also still exists when the distortion problem of the heat dissipating plates is remedied; the hot solder still flows down and concentrates at the lower semi-circle of the circular wall.  
      Yet another variation of the structure of the heat pipe and the heat dissipating fin module is disclosed in a Taiwan design patent, No. 491517, a formed structure of heat dissipating fin. The invention includes a heat pipe and several heat dissipating fins with holes bored through them. There are conjoining sections which extend from one side of the bored holes, and narrow slots cut from the upper portions of the holes and the conjoining sections. The heat pipe is forcibly inserted into the bored holes and the conjoining sections of the heat dissipating fins. A third metal material, such as silver, tin, or copper filament, is inserted into the narrow slot, and further soldered onto the slot. The heat dissipating fins are, thereby, combined with the heat pipe. However, this structure requires the insertion and soldering of the third metal material. The third metal material cannot thoroughly flow into the gap which is between the bored hole and the heat pipe. Because of this, many gaps still remain between the bored holes and the heat pipe.  
     BRIEF SUMMARY OF THE INVENTION  
      The present invention is to remedy the poor thermal connection problem of the conventional art, which is caused by the forcibly insertion of the heat pipe, and the difficulty of adhesive applying.  
      The heat pipe heat sink provided by the present invention has a holeless heat dissipating fin module which is not only much more convenient for manufacturing a heat pipe heat sink, but also capable of quickly transferring the heat generated by an electrical component into the heat pipe and uniformly distributing the heat to each of the heat dissipating fins.  
      The heat pipe heat sink includes a heat dissipating fin module, a heat conducting member, one or more heat pipes installed on the heat conducting member, and a heat conducting plate which is thermally connected to the heat conducting member and the electrical component. The heat pipe is semi-inserted into the concave trench of the heat conducting member with a portion of its surface exposed from the concave trench. The end surface of the heat conducting member with the heat pipe installed thereon is convenient for application of an adhesive. This convenient application is achieved because the end surface and the pipe wall of the heat pipe are exposed outside of the heat dissipating fin module before any combination takes place.  
      The top of the heat conducting plate is attached to the bottom surface of the heat conducting member, while the bottom of the heat conducting plate is thermally connected to the top surface of an electrical component. Via the heat conducting plate, a uniform heat connection end surface is formed below the heat conducting member. The heat transferred into the heat conducting plate has dual routes for simultaneous transfer; heat can be transferred to the heat dissipating fin module via either the heat conducting member or the heat pipe. The heat transferred is equally distributed among the heat dissipating fins of the heat dissipating fin module for quick dissipation into the surrounding air. The present invention more efficiently dissipates heat than the conventional art. The present invention, therefore, enhances the state of the art.  
      These and other objectives of the present invention will become obvious to those of ordinary skill in the art after reading the following detailed description of preferred embodiments.  
      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  
      These as well as other features of the present invention will become more apparent upon reference to the drawings therein:  
       FIG. 1  is a front view of a conventional heat pipe heat sink.  
       FIG. 2  is an exploded view of the heat transferring member including the conducting member, the heat conducting plate, and the heat pipe of a heat pipe heat sink of the present invention.  
       FIG. 3  is a partial exploded view of a heat pipe heat sink of the present invention.  
       FIG. 4  is a perspective view of a heat pipe heat sink of the present invention fully combined.  
       FIG. 5  is a cross-sectional view of a heat pipe heat sink of the present invention.  
       FIG. 6  is a cross-sectional view of a heat pipe heat sink which is placed onto a electrical component.  
       FIG. 7  is a cross-sectional view of another embodiment of a heat pipe heat sink of the present invention.  
       FIG. 8  is a cross-sectional view of still another embodiment of a heat pipe heat sink of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Reference will now be made in detail to the preferred embodiments of the present 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.  
      Referring to  FIGS. 2 through 5 , one preferred embodiment of a heat pipe heat sink of the present invention is shown. The heat pipe heat sink includes a heat dissipating fin module  1 ; a heat conducting member  2  which is combined with the heat dissipating fin module  1 ; one or more heat pipes installed on the heat conducting member  2 , which is thermally connected to the heat dissipating fin module  1 ; and a heat conducting plate  4  which is thermally connected to the end surface of the heat conducting member  2 .  
      The heat dissipating fin module  1 , as illustrated in  FIG. 3 , is assembled by stacking a plurality of independent heat dissipating fins  11 . The heat dissipating fin module  1  has a connecting portion  12  concavely formed on one end thereof, which is utilized to thermally connect the heat dissipating fin module  1  to the heat conducting member  2  and the heat pipe  3 . The connecting portion  12  is constituted by a plurality of connecting ends  13  of the heat dissipating fins  11 . The connecting end  13  is formed by bending one edge of the heat dissipating fins  11 . Unlike the conventional heat pipe heat sink, the present invention does not require that any holes be bored through the heat dissipating fins  11 . The present invention is a heat pipe heat sink without any holes bored through the heat dissipating fin module thereof.  
      The heat conducting member  2  is a block shaped structure composed of a highly conductive material. There is no special limit regarding the shape of the heat conducting member  2 . The only requirement of the heat conducting member  2  is that its shape fits with the connecting portion  12  of the heat dissipating fin module  1 , and thermally connects the heat connecting member  2  to the heat conducting plate  4 . The trapezoid structure disclosed in  FIG. 2  is only one of the possible structures of the heat conducting member  2 . The heat conducting member  2  has a plurality of concave trenches  21  formed on the end surfaces  20  thereof in order to be assembled with one or more heat pipes  3  by semi-insertion.  
      The heat pipe  3  is inserted into a pair of concave trenches  21  of the heat conducting member  2 . The pipe body  30  of the heat pipe  3  is embedded inside the concave trench  21 , while the planar pipe wall  31  of the heat pipe  3  is exposed outside and coplanar with the end surface  20  of the heat conducting member  2 .  
      The heat conducting plate  4  is constructed from a highly conductive plate material. The heat conducting plate  4  includes an upper surface  41  and a lower surface  42 . The upper surface  41  of the heat conducting plate  4  is attached to the bottom surface of the heat conducting member  2 , and is thermally connected to the planar pipe walls  31  of the heat pipe  2 . The preferred thermal connection is a high fitness surface contact connection, as illustrated in  FIG. 3  and  FIG. 4 . Thereby, a regular heat connection end surface is formed below the heat conducting member  2 . The lower surface  42  of the heat conducting plate  4  is thermally connected to the top surface of an electrical component  5 . Via the heat conducting plate  4 , the heat which is generated by the electrical component  5  can quickly be transferred into the heat pipe  3  and uniformly distributed to each of the heat dissipating fins  11 .  
       FIGS. 3 through 6  illustrate the assembling of the aforementioned members and the thermal connection which is utilized by the heat pipe heat sink. The heat pipe  3  is semi-inserted into the concave trenches  21  of the heat conducting member  2  as shown in  FIG. 3 . The planar pipe wall  31  of the heat pipe  3  is coplanar with the end surface  20  of the heat conducting member  2 . Thereby, the conducting member  2  has one or more regular planar end surfaces with the heat pipe  3  installed thereon. The end surface  20  of the heat conducting member  2  with the heat pipe  3  installed thereon provides for convenient application of an adhesive such as tin solder. This convenient application is achieved because the end surface  20  and the planar pipe wall  31  of the heat pipe  3  are exposed outside of the heat dissipating fin module  1  before any combination takes place. The present invention is much more convenient for manufacturing a heat pipe heat sink when compared to the conventional art which can only inject the adhesive from the edge of the heat sink.  
      The planar end surface of heat conducting member  2  installed with the heat pipe  3  is correspondingly assembled and thermally connected to the connecting portion  12  of the heat dissipating fin module  1 . The combination of the planar pipe wall  31  of the heat pipe  3  and the connecting portion  12  of the heat dissipating fin module  1  is, therefore, a high fitness multi-areas contact combination as illustrated in  FIGS. 4 and 5 . It is unnecessary for the present invention to use a machine to forcibly insert the heat pipe into the heat dissipating fin and the heat conducting member. The cost of manufacturing a heat pipe heat sink is reduced. Further, the heat conducting member  2  is thermally connected to the electrical component  5  by utilizing the heat conducting plate  4  which is placed thereon, as is illustrated in  FIG. 6 . The heat transferred into the heat conducting plate  4  has dual routes for simultaneous transfer; heat can be transferred to the heat dissipating fin module via either the heat conducting member  2  or the heat pipe  3 . The heat transferred is equally distributed among the heat dissipating fins  11  of the heat dissipating fin module  1  for quick dissipation into the surrounding air. The present invention more efficiently dissipates heat than the conventional art. The present invention, therefore, enhances the state of the art.  
      Referring to  FIG. 7 , another embodiment of a heat pipe heat sink of the present invention is shown. The members making up the heat pipe heat sink are similar to those of the aforementioned embodiment. The heat pipe heat sink includes a heat dissipating fin module  1 ; a heat conducting member  2  which is combined with the heat dissipating fin module  1 ; one or more heat pipes installed on the heat conducting member  2 , which is thermally connected to the heat dissipating fin module  1 ; and a heat conducting plate  4  which is thermally connected to the end surface of the heat conducting member  2 . The major difference between this embodiment and the former one is the configurations of the connecting portion  12  of the heat dissipating fin module  1  and the heat pipe  3 . The heat dissipating fin  11  of this embodiment has one or more concave portions  14  formed on the bottom thereof, while a portion of the heat pipe  3  has a cylindrical shape. The concave portion  14  fits with the pipe wall  31  of the heat pipe  3  exposed above the concave trench  21 . The pipe wall  31  exposed above the trench  21  is thermally connected to the concave portion  14  of the heat dissipating fin  11 . This embodiment is capable of achieving the same effects of the mentioned embodiment including a high fitness multi-areas contact thermal connection and a better heat dissipating efficiency.  
      In aforementioned embodiments, because the heat pipe  3  has a plane bottom, the combination of the heat conducting member  2  and the heat conducting plate  4  is a planar surface attachment. In another embodiment the heat pipe  3  may has a cylindrical shape, while the heat conducting plate  4  may accordingly change the shape thereof. Referring to  FIG. 8 , one or more concave trenches  43  is cut from the top surface  41  of the heat conducting plate  4  in order to fit with the shape of the heat pipe  3 . The amount and the location of the concave trenches  43  are corresponding to those of the concave trenches  21  of the heat conducting member  2 . Via the concave trenches  43 , the heat conducting plate  4  is thermal connected to the heat pipe  3 . The heat generated by the electrical component  5  can quickly be transferred into the heat pipe  3  and uniformly distributed to each of the heat dissipating fins  11 . The embodiment is also capable of achieving a high fitness area contact thermal connection and a better heat dissipating efficiency.