Patent Publication Number: US-2007107874-A1

Title: Water Cooling Type Heat Dissipation Apparatus with Parallel Runners

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a heat dissipation structure, especially to a water cooling type heat dissipation structure for an electronic device.  
      2. Description of Prior Art  
      Heat generation is inevitable for any electronic device due to friction and efficiency problem. Some integrated circuits have serious heat dissipation problem for their compact size. Moreover, computer will generate more heat as the performance thereof is increased. Besides CPU, other components in computer such as chipset, graphic processor, DRAM and hard disk module will also produce considerable heat. Therefore, heat dissipation devices are necessary to remove heat from computer and to ensure normal operation of computer.  
      For example, electrical fan is often used as heat dissipation device and wind is generated by the electrical fan to remove heat from computer. However, the electrical fan can remove heat from a contact area between it and the heat generating element. Moreover, heat dissipation fins can also be attached to the surface of the heat generating element to increase the area for heat dissipation by electrical fan. However, the electrical fan can generated limited wind amount. Multiple electrical fans can be used to increase wind amount, however, it will occupy more space. Moreover, noise generates when the rotational speed of the electrical fan is increased.  
      Another prior art heat dissipation device is water cooling type heat dissipation device. A heat dissipation stage is arranged on the heat generating element such as CPU or hard disk. Liquid coolant is guided into the heat dissipation stage from a water tank by motor. The liquid coolant is heat exchanged with the heat generating element and the hot liquid coolant is cooled by a heat dissipation module and then flows back to the water tank. Therefore, heat can be removed from the heat generating element.  
      The liquid coolant has heat exchange with heat source and has better heat dissipation effect than air type heat dissipation device. However, the heat absorbing end of the heat dissipation stage is concentrated on the same place in above-mentioned prior art. Only part of the liquid coolant has heat exchange with the heat absorbing end. The liquid coolant remains in the heat dissipation stage for only very short time such that the liquid coolant exits through another channel before absorbing enough heat.  FIG. 1  shows another prior art water cooling type heat dissipation device. The heat dissipation stage  101  is provided with a plurality of heat dissipation plates  102  arranged in upward and downward stagger fashion to form a single-direction runner. Therefore the liquid coolant stays longer when it flows through the staggering runner. The plurality of heat dissipation plates  102  increase heat dissipation area. However, the flow direction of the liquid coolant is parallel to the substrate of the heat dissipation stage. The liquid coolant flows out of the heat dissipation stage  101  soon and has not enough heat exchange with the heat dissipation plates  102 .  
     SUMMARY OF THE INVENTION  
      The present invention intends to provide a heat dissipation apparatus with multiple parallel runners defined by a plurality of heat dissipation fins and heat conduction post. Heat is absorbed by the heat conduction post and is conducted to the heat dissipation fins. Liquid coolant flows through the runners and is resisted by the heat conduction post. Therefore the liquid coolant stays longer in the runners and has sufficient heat exchange with the heat dissipation fins to enhance heat dissipation effect. 
    
    
     BRIEF DESCRIPTION OF DRAWING  
      The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself however may be best understood by reference to the following detailed description of the invention, which describes certain exemplary embodiments of the invention, taken in conjunction with the accompanying drawings in which:  
       FIG. 1  shows another prior art water cooling type heat dissipation device.  
       FIG. 2  shows a top view of upper cover of the present invention.  
       FIG. 3  shows a top view of lower cover of the present invention.  
       FIG. 4  shows an exploded view of the present invention.  
       FIG. 5  shows the operation of the present invention.  
       FIG. 6  shows an exploded view of another preferred embodiment of the present invention.  
       FIG. 7  shows the operation of another preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      With reference to FIGS.  2  to  4 , the heat dissipation stage  1  of the present invention comprises an upper cover  11  and a lower cover  12  to form a hollow closed box. The shape of the heat dissipation stage  1  of the present invention can be various according to practical need. In this shown preferred embodiment, the upper cover  11  and the lower cover  12  are of (but not limited to) rectangular shape, and made of heat conduction material such as metal or ceramics. The upper cover  11  and the lower cover  12  are assembled by soldering, riveting or bounding. Moreover, the upper cover  11  comprises a concave  113  on inner side thereof and a first passageway  111  and a second passageway  112  on left side and right side thereof (or upper side) for providing channel for liquid coolant to enter or exit the heat dissipation stage  1 . The lower cover  12  comprises a contact face  121  on bottom side thereof and used for contacting the heat source.  
      The lower cover  12  comprises at leas one heat conduction post  2  on inner side thereof (only one in this embodiment). The heat conduction post  2  is made of heat conduction material such as metal or ceramics. In the preferred embodiment, the heat conduction post  2  is copper post. A plurality of heat dissipation fins  31  are arranged on the heat conduction post  2  and parallel to the lower cover  12  to form a heat dissipation fin set  3 . A plurality of parallel runners  50  is defined between the plurality of heat dissipation fins  31  and parallel to each other. The heat dissipation fin set  3  can be also made of heat conduction material as that of the heat conduction post  2 , and can be assembled through soldering, tightening or binding.  
      With reference to  FIG. 5 , when the upper cover  11  and the lower cover  12  is assembled to form the heat dissipation stage  1 , the contact face  121  on bottom side of the lower cover  12  is attached to a heat generating element  4  (such as CPU or other heat generating chip). The heat generated by the heat generating element  4  is conducted to the heat conduction post  2  inside the heat dissipation stage  1  and then conducted to the heat dissipation fin set  3  through the heat conduction post  2 . Afterward, liquid coolant (shown by arrow) is guided to the parallel runners  50  through the first passageway  111 . The heat conduction post  2  provides flow resistant function to increase stay time of the liquid coolant. Therefore, the liquid coolant has sufficient heat exchange with the heat dissipation fin set  3  to absorb more heat from the heat generating element  4  and then the liquid coolant flows through the second passageway  112 .  
       FIG. 6  shows the exploded view of another preferred embodiment of the present invention. There are a plurality of heat conduction posts  2  on the lower cover  12 . A plurality of heat dissipation fins  31 - 34  are arranged on the heat conduction posts  2  and parallel to the lower cover  12  to form a heat dissipation fin set  3 . A first baffle  122  is arranged vertically on the lower cover  12  and near the first passageway  111 . First sides of the odd-layer heat dissipation fins  31  and  33  are vertically connected to the first baffle  122 . The height of the first baffle  122  is even with top edge of the heat dissipation fin  31 . First sides of the even-layer heat dissipation fins  32  and  34  have predetermined separation  60  with the first baffle  122 . A second baffle  114  is arranged on the concave  113  and near the second passageway  112 . When the upper cover  11  and the lower cover  12  are assembled, the second sides of the even-layer heat dissipation fins  32  and  34  are vertically connected to the second baffle  114 , while the second baffle  114  has predetermined separation  60  with the second sides of the odd-layer heat dissipation fins  31  and  33 . The bottom edge of the second baffle  114  is even with the fourth heat dissipation fin  34 .  
       FIG. 7  shows the operation of the second preferred embodiment of the present invention. When liquid coolant (as shown by arrow) flows into the heat dissipation stage  1  through the first passageway  111 , the liquid coolant is blocked by the first baffle  122  to flow toward parallel runners  50  defined by the first heat dissipation fin  31  and the upper cover  11 . The liquid coolant then flows downward to parallel runners  50  defined by the first heat dissipation fin  31  and the second heat dissipation fin  32 , where part of the liquid coolant is blocked by the second baffle  114  and then flows downward to the parallel runners  50 . Therefore, the liquid coolant flows in parallel or downwardly through the plurality of runners defined by the heat dissipation fin set  3  until flows to the parallel runner  50  defined by the fourth heat dissipation fin  34  and the lower cover  12 . Afterward the liquid coolant exits through the second passageway  112 . Those parallel runners  50  are communicated to form a single-direction winding parallel runner  50 . Therefore, the liquid coolant is resisted by the winding parallel runner  50  and the heat conduction post  2  to stay longer in the parallel runners  50 . The heat of the heat generating element  4  is conducted to the heat dissipation stage  1  through the contact face  121  and conducted vertically to the heat dissipation fin set  3  through the heat conduction post  2 . The heat is then heat-exchanged with the liquid coolant to achieve excellent heat dissipation effect. Moreover, the liquid coolant can also flows into the heat dissipation stage  1  through the second passageway  112  and then flows along the same parallel runners  50  but in reverse direction. Afterward the liquid coolant exits through the first passageway  111 .  
      Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.