Patent Publication Number: US-2006000583-A1

Title: Heat dissipating device

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates to a heat dissipating device, more particularly to a heat dissipating device that can provide an enhanced heat-dissipating effect through a heat-exchanging working fluid therein.  
      2. Description of the Related Art  
       FIG. 1  illustrates a conventional heat dissipating device  1  for dissipating heat generated by a heat-generating component  2  mounted on a circuit board  2 . The conventional heat dissipating device  1  includes a heat dissipating fin unit  11  having a plurality of heat-dissipating fin plates  111  and placed in contact with the heat-generating component  21 , and a fan unit  12  mounted on the heat-dissipating fin unit  11 . Since the conventional heat dissipating device  1  is relatively thick, the conventional heat dissipating device  1  is not suited for application to an electronic apparatus with a reduced profile.  
     SUMMARY OF THE INVENTION  
      Therefore, the object of the present invention is to provide a heat dissipating device that can provide an enhanced heat-dissipating effect through a heat-exchanging working fluid therein and that is suitable for low-profile applications.  
      According to the present invention, there is provided a heat dissipating device for dissipating heat generated by a heat source. The heat dissipating device comprises: 
          a first fluid container containing an amount of working fluid therein, the working fluid being capable of changing into fluid vapor when heated, the fluid vapor being capable of changing into fluid condensate when cooled, the first fluid container having a first fluid outlet and a first fluid inlet;     a second fluid container made of a heat conductive material and having a device contacting side adapted to be placed in contact with the heat source, the second fluid container confining first and second accommodating spaces that are in fluid communication with each other, and having a second fluid inlet for access into the first accommodating space, and a second fluid outlet for access into the second accommodating space;     a supply pipe interconnecting the first fluid outlet of the first fluid container and the second fluid inlet of the second fluid container;     a return pipe interconnecting the first fluid inlet of the first fluid container and the second fluid outlet of the second fluid container;     a first check valve unit for permitting flow of the working fluid from the first fluid container into the first accommodating space of the second fluid container via the supply pipe when a fluid pressure in the first fluid container is greater than that in the second fluid container; and     a second check valve unit for permitting fluid flow from the second accommodating space into the first fluid container via the return pipe when the fluid pressure in the first fluid container is less than that in the second fluid container.       

    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:  
       FIG. 1  is a schematic view of a conventional heat dissipating device;  
       FIG. 2  is a fragmentary perspective view showing the first preferred embodiment of a heat dissipating device according to this invention;  
       FIG. 3  is a perspective view showing the first preferred embodiment when installed in a computer apparatus; and  
       FIG. 4  is a fragmentary schematic view showing the second preferred embodiment of a heat dissipating device according to this invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.  
       FIGS. 2 and 3  illustrate the first preferred embodiment of a heat dissipating device  3  for dissipating heat generated by a heat source according to the present invention. The heat dissipating device  3  includes a first fluid container  32 , a second fluid container  31 , a supply pipe  33 , a return pipe  34 , a first check valve unit  35 , and a second check valve unit  36 . In this embodiment, the heat source is an electronic component  421  mounted on a main board  42  in a computer housing  41  (see  FIG. 3 ). The heat dissipating device  3  is adapted to be disposed in the computer housing  41 .  
      The first fluid container  32  contains an amount of working fluid  322  therein. The working fluid  322  is capable of changing into fluid vapor when heated. The fluid vapor is capable of changing into fluid condensate when cooled. The first fluid container  32  has a first fluid outlet  323  and a first fluid inlet  324 . In this embodiment, the first fluid container  32  is made of a heat conductive material, and is adapted to be disposed adjacent to a plurality of vent holes  412  in the computer housing  41 . The working fluid  322  is a heat exchanging coolant.  
      The second fluid container  31 , which is made of a heat conductive material, is substantially flat in this embodiment, and has a device contacting side  311  adapted to be placed in contact with the electronic component  421 , as best shown in  FIG. 3 . The second fluid container  31  is partitioned into first and second accommodating spaces  314 ,  315  that are in fluid communication with each other, and has a second fluid inlet for  316  for access into the first accommodating space  314 , and a second fluid outlet  317  for access into the second accommodating space  315 .  
      The supply pipe  33  interconnects the first fluid outlet  323  of the first fluid container  32  and the second fluid inlet  316  of the second fluid container  31 . In this embodiment, the supply pipe  33  is made of a heat conductive material.  
      The return pipe  34  interconnects the first fluid inlet  324  of the first fluid container  32  and the second fluid outlet  317  of the second fluid container  31 . In this embodiment, the return pipe  34  is made of a heat conductive material.  
      The first check valve unit  35  permits flow of the working fluid  322  from the first fluid container  32  into the first accommodating space  314  of the second fluid container  31  via the supply pipe  33  when a fluid pressure in the first fluid container  32  is greater than that in the second fluid container  31 . In this embodiment, the first check valve unit  35  includes two first check valves  351 ,  352  that are respectively provided at the first fluid outlet  323  of the first fluid container  32  and the second fluid inlet  316  of the second fluid container  31 .  
      The second check valve unit  36  permits fluid flow from the second accommodating space  315  of the second fluid container  31  into the first fluid container  32  via the return pipe  34  when the fluid pressure in the first fluid container  32  is less than that in the second fluid container  31 . In this embodiment, the second check valve unit  36  includes two second check valves  361 ,  362  that are respectively provided at the second fluid outlet  317  of the second fluid container  31  and the first fluid inlet  324  of the first fluid container  32 .  
       FIG. 4  illustrates the second preferred embodiment of a heat dissipating device  3 ′ according to this invention, which is a modification of the first preferred embodiment. In this embodiment, the heat dissipating device  3 ′ further includes a heat dissipating fin unit  54  mounted on the second fluid container  31  and having a plurality of heat-dissipating fin plates  541 .  
      To sum up, due to the supply and return pipes  33 ,  34  and the first and second check valve units  35 ,  36 , the heat dissipating device  3 ,  3 ′ of this invention can achieve an enhanced heat dissipating effect through a heat-exchanging the working fluid  322  therein, the working fluid  322  being circulated as a result of a fluid pressure difference between the first and second fluid containers  32 ,  31 . Furthermore, since a fan unit is not required, the heat dissipating device  3 ,  3 ′ of this invention is relatively thin and is thus suitable for low-profile applications.  
      While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.