Patent Publication Number: US-2009225511-A1

Title: Heat sink module

Description:
This application claims the priority benefit of Taiwan patent application number 097203941 filed on Mar. 7, 2008. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a heat sink module. More particularly, the present invention relates to a heat sink module for producing air circulation to quickly dissipate the heat energy, which comprises a first fan and at least one second fan coaxially connected together for heat dissipation rapidly. 
     2. Description of Related Art 
     Along with the rapidly developing technology, the electronic and electrical devices are essential for everyday activities of people&#39;s daily lives. Especially, the number of computer users is significantly increasing nowadays. For satisfying the increasing number of computer users, the computer motherboard is upgraded to provide more powerful processing and calculating abilities. The dual-processor chip helps to improve the processing speed to enable the computer to calculate, to process and to execute at a much faster speed. However, the increasing the processing speed correspondingly increases generation of heat energy, and the general method for dissipating the heat energy from the motherboard is to equip the computer with heat sink fins and a fan on the heat source. The heat sink fins are used for absorbing the heat energy from the heat source, and the fan is used for blowing the cold air to the heat sink fins, thus the heat energy absorbed by the heat sink fins can dissipated to the outside. The present installation method includes positioning the fan above the heat sink fins; and therefore when the fan blows the cold air toward the heat sink fins, the different types of heat sink fins will affect the air circulation and the speed of heat dissipation. Therefore, the conventional heat dissipation manner has the following defects. 
     1. The heat sink fins are designed in different types with different gaps positioning means there-between, and the fan blows the cold air vertically above the heat sink fins, and therefore, the heat dissipation effect is poor at the bottom of the heat sink fins. 
     2. The heat sink fins are attached to the heat source. In other words, the central region of the bottom portion of the heat sink fins is the hottest region but the cold air from the fan cannot reach easily. 
     3. The fan usually operates for drawing or blowing air. Although the heat energy can be removed from the heat sink fins, the residual heat still remains on the heat sink fins to affect the heat dissipation efficiency. 
     Therefore, how to solve the above defects has become the important issue for the suppliers in the field. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a heat sink module capable of rapidly dissipating the heat. 
     According to an aspect of the present invention, the heat sink module comprises a heat sink plate which has a chassis for attaching to a heat source, a plurality heat sink fins and a receiving space, and an fan assembly positioned near the receiving space for heat dissipation into the outside open air. The fan assembly comprises a first fan, at least one second fan received in the receiving space and connected to the first fan by a core shaft extending downwardly from the first fan, and a drive unit connected with the core shaft for driving the first fan and the second fan to rotate. Thus, the heat energy can be rapidly dissipated from the heat sink plate into the outside. 
     According to another aspect of the present invention, the heat sink plate comprises a closed receiving space at a central region of the heat sink fins, which has a closed outer sidewall and a plurality of through holes cut around the outer sidewall. The heat sink module of the present invention further comprises a case covered along the peripheral of the heat sink fins. When the first fan and the second fan of the fan assembly are driven by the drive unit to rotate, the second fan in the closed receiving space could move the heat energy toward the heat sink fins, and the barricade formed by the case provides a chimney effect between the plurality of heat sink fins to enable the heat air to go upward to further allow the first fan to draw the heat air for dissipation into the outside open air. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is an exploded view of a heat sink module according to an embodiment of the present invention. 
         FIG. 2  is a sectional side view of  FIG. 1 . 
         FIG. 3  is a sectional side view of a heat sink module according to a preferred embodiment of the present invention, showing a case covered on the heat sink plate. 
         FIG. 4  is a sectional side view of a heat sink module according to alternate embodiment of the present invention. 
         FIG. 5  is an exploded view of a heat sink module according to still another embodiment of the present invention. 
         FIG. 6  is a sectional side view of  FIG. 5 . 
         FIG. 7  is an exploded view of a heat sink module according to still another embodiment of the present invention. 
         FIG. 8  is a sectional side view of  FIG. 7 . 
     
    
    
     DETAIL DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , a heat sink module in accordance with the present invention is shown comprised of a heat sink plate  1  and a fan  2  assembly. 
     The heat sink plate  1  comprises a chassis  11 , a plurality of heat sink fins  12  positioned above, and a receiving space  13  formed at the central region of the heat sink fins  12 . The adjacent heat sink fins  12  have a gap  121  in communication with the receiving space  13 . 
     The fan assembly  2  comprises a fan body  21 , an accommodation chamber  22  defined within the fan body  21 , a drive unit  23  positioned in the accommodation chamber  22 , a first fan  24  having a plurality of radial blades, and a second fan  25  mounted on the first fan  24 . The first fan  24  comprise a core shaft  241  extending downwardly for connecting with the drive unit  23 , thus, the second fan  25  and the first fan  24  are coaxially connected by the core shaft  241  to enable the second  25  rotate along with the first fan  24 . 
     During installation of the present invention, the drive unit  23 , the first fan  24  and the second fan  25  are positioned in the accommodation chamber  22  of the fan assembly  2 , then, the fan body  21  with the drive unit  23 , the first fan  24  and the second fan  25  is capped on the heat sink fins  12  of the heat sink plate  1  to receive the second fan  25  in the receiving space  13  and to have the first fan  24  positioned above the receiving space  13  near the heat sink fins  12 . 
     To operate the heat sink module of the present invention, the chassis  11  of the heat sink plate  1  can be affixed or assembled on a heat source  3  of a mainboard. When the heat source  3  generates heat energy, the plurality of heat sink fins  12  absorb the heat energy from the heat source  3 , and the drive unit  23  of the fan assembly  2  drives the first fan  24  and the second fan  25  to rotate. The second fan  25  directly blows the cold air into the receiving space  13  where it is the hottest region in the heat sink plate  1  and blows the heat air out of the heat sink fins  12 . Meanwhile, the first fan  24  positioned above the receiving space  13  near the heat sink fins  12  also rotate for dissipation the heat energy away from the heat sink fins  12  into the outside open air. Therefore, the first fan  24  and the second fan  25  can coordinate with each other to rapidly dissipate the heat energy away from the heat sink fins  12  by blowing and drawing air to substantially cool down the hottest region in the heat sink plate  1 . 
     The first fan  24  of the fan  2  can be not only blowing air but also drawing air, and is coaxially connected with the second fan  25  by the core shaft  241 . Therefore, the first fan  24  and the second fan  25  can rapidly dissipate the heat energy away from the heat sink plate  1  by blowing and drawing air. 
     The shape of the heat sink plate  1  can be rectangle, circle or other shapes, and the receiving space  13  at the central region is used to receive the second fan  25  of the fan assembly  2  after installing. 
     Referring  FIGS. 3˜4  and  1  again, a case  4  comprises at least two buckling portions  41  for engagement with the fan assembly  2  to further cover the outline of the heat sink plate  1 . When the second fan  25  blows the cold air to the heat sink fins  12 , the barricade formed by the case  4  provides a chimney effect to allow the first fan  24  near the receiving space  13  to draw the heat air for dissipation into the outside open air, and thereby prevent the heat air from flowing along the gaps  121  of the heat sink fins  12  to affect the surrounding components. Therefore, the heat dissipation direction can be substantially and effectively controlled. 
     Besides, the core shaft  241  of the first fan  24  can be used to joint two (or at least one) second fans  25  to increase the wind power to blow the cold air to the plurality of heat sink fins  12 , and thereby effectively increase the heat dissipation effect of the heat sink plate  1 . When rotating the second fans  25 , the cold air flows over not only the hottest region at the bottom of the receiving space  13 , but also the gaps  121  between the plurality of the heat sink fins  12 . Meanwhile, the first fan  24  positioned above the indented space  13  near the plurality of heat sink fins  12  absorbs the heat energy from the heat sink fins  12 . Thus, the heat sink plate  1  can dissipate the heat energy from the heat source  3  effectively. 
       FIGS. 5 and 6  show still another form of the present invention. The embodiment is substantially similar to the embodiment shown in  FIG. 1  with exception that the heat sink plate  1  and the fan body  21  of the fan assembly  2  are a circular shape respectively. The circular heat sink plate  1  comprises a receiving space  13  at a center, and a plurality of heat sink fins  12  radially positioned extending from the receiving space  13 . The second fan  25  of the fan assembly  2  can be received in the receiving space  13 . After the first fan  24  and the second fan  25  are driven by the drive unit  23  to rotate, the circulative air current is flowing around the inner side of the receiving space  13  and the first fan  24  is used to draw the heat air from the receiving space  13  to substantially assist the heat dissipation of the heat sink plate  1 . 
       FIGS. 7 and 8  show still another form of the present invention. According to this embodiment, the heat sink plate  1  comprises a closed receiving space  13  at the center thereof, which has a closed outer sidewall  131  and a plurality of through holes  132  on the outer sidewall  131 . When the second fan  25  of the fan assembly  2  is received in the closed receiving space  13 , the drive unit  23  can drive the first fan  24  and the second fan  25  to draw and blow air current respectively. The cold air from the second fan  25  in the closed receiving space  13  flows through the through holes  132  of the outer sidewall  131  to outside, and further the first fan  24  draws the heat air for dissipation into the outside open air. 
     Besides, a case  4  may surround along the peripheral of the heat sink plate  1 . When driving the second fan  25  in the closed receiving space  13  to rotate, the cold air flows through the through holes  132  of the outer sidewall  131  to outside and is blocked by the case  4 . The barricade formed by the case  4  provides a chimney effect between the plurality of heat sink fins  12  to enable the heat air to go upward to further allow the first fan  24  to draw the heat air for dissipation into the outside open air. 
     As stated above, the invention provides a heat sink module, which comprises a heat sink plate  1  and a fan assembly  2  for heat dissipation. The heat sink plate  1  comprises a chassis  11 , a plurality of heat sink fins  12  positioned on the chassis  11 , and a receiving space  13  at the central region of the heat sink fins  12  for receiving a second fan  25  connected with a first fan  24  of the fan assembly  2 . The first fan  24  and the second fan  25  of the fan assembly  2  can blow and draw air together to assist the heat sink plate  1  to achieve rapid heat dissipation. Besides, a case  4  may cover along the outline of the heat sink plate  1  to provide a chimney effect, and the rising heat air from the plurality of heat sink fins  12  can be drawn by the first fan  24  to the outside open air. 
     Accordingly, the present invention has at least following advantages. 
     1. The heat sink plate  1  has a receiving space  13  at the central region of the plurality of heat sink fins  12  for receiving the second fan  25 . The second fan  25  can blow the cold air toward the central region of the heat sink plate  1  directly, and the first fan  24  can draw the heat air for heat dissipation coordinately. Thus, the heat energy can be rapidly dissipated from the heat sink plate  1 . 
     2. The first fan  24  can draw the heat air and the second fan  25  can blow the cold air to assist the heat sink plate  1  for heat dissipation rapidly. 
     3. By covering a case  4  on the outline of the heat sink plate  1 , a chimney effect will form between the plurality of heat sink fins  12 , and the first fan  24  can draw the rising heat air for dissipation. 
     4. The heat sink plate  1  comprises a closed receiving space  13 , which has a closed outer sidewall  131  and a plurality of through holes  132  cut around the outer sidewall  131 . At the same time, a case  4  is covered on the peripheral of the heat sink plate  1 . Thus, a chimney effect will form between the plurality of heat sink fins  12 , and the first fan  24  can draw the rising heat air for dissipation. 
     Although particular embodiments of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be may without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.