Patent Publication Number: US-2009223651-A1

Title: Panel heat-dissipating device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a heat sink, and in particular to a panel heat-dissipating device formed by means of extending a vapor chamber. 
     2. Description of Prior Art 
     Since the computer is widely used to various applications and is designed to be more and more compact, the heat-dissipating device provided in the computer has to be modified according to the cases applied by the central processing unit within the computer. For example, in the case of the heat-dissipating device for a personal computer, since the space within the personal computer is larger, there is enough space for mounting a fan. Therefore, a heat sink made of aluminum and copper material can cooperate with an associated fan to perform heat dissipation. However, if the heat-dissipating device is to be used in a notebook or a portable computer, since the internal space is restricted, the common aluminum-extruded heat sink cannot be used and the fan is also limited to a centrifugal fan. 
     In addition, heat-conducting elements generating a heat-conducting effect via circulative change in vapor/liquid phases (such s a heat pipe or a vapor chamber) are often used in the field of heat dissipation. Especially, since the heat pipe can be manufactured more easily and does not occupy too much space, it can be extended in the lengthwise direction of the heat pipe. After the heat generated by the central processing unit is conducted transversely toward a heat-dissipating region, the heat can be further dissipated via heat-dissipating means such as fins or fans. Therefore, the heat pipe is very suitable for the cases in which the internal space is restricted, such as a notebook. The vapor chamber is often used to replace a solid base on the heat sink. Although the principle of the vapor chamber is the same as that of the heat pipe, in practice, the vapor chamber can be used to other cases different from those of the heat pipe because of the difference in their profiles. 
     Although the heat pipe occupies less space, comparing the diameter of the heat pipe with the thickness of the vapor chamber, the vapor chamber has advantage over the heat pipe in terms of compactness. However, the manufacture of the vapor chamber may be restricted due to the larger surface area thereof. Further, the main body of the vapor chamber may be recessed inwardly during a degassing process. As a result, the surface of the vapor chamber may not be flat enough to be attached to a heat source. Therefore, a good thermal contact effect cannot be achieved. 
     SUMMARY OF THE INVENTION 
     The present invention is to provide a panel heat-dissipating device. With a smaller thickness of the vapor chamber, the heat-dissipating device can be made more compact. Further, a heat-conducting path can be extended in the lengthwise direction of the heat-dissipating device. The heat-conducting base and the fin assembly of the heat-dissipating device are located on the same side of the vapor chamber, which reduces the space in the height of the heat-dissipating device. Thus, it can be applied to the cases that the height and thickness thereof are restricted. 
     The present invention provides a panel heat-dissipating device, which includes a heat-conducting base, a vapor chamber, and at least one fin assembly. The heat-conducting base has a heat-conducting surface for allowing the vapor chamber to be thermally connected thereon. The vapor chamber forms extending portions toward the lateral of the heat-conducting base. The extending portion of the vapor chamber toward the lateral of the heat-conducting base allows the fin assembly to be disposed thereon. The fin assembly and the heat-conducting base are located on the same side of the vapor chamber. Via this arrangement, a panel heat-dissipating device can be obtained. Further, since the fin assembly and the heat-conducting base are located on the same side of the vapor chamber, the above objects can be achieved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of the present invention; 
         FIG. 2  is an assembled perspective view of the present invention; 
         FIG. 3  is a cross-sectional view of the present invention; 
         FIG. 4  is an enlarged view showing the details of portion A in  FIG. 3 ; and 
         FIG. 5  is a schematic view showing the operating state of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In order to make the Examiner to better understand the characteristics and technical contents of the present invention, a detailed description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only, but not used to limit the present invention. 
       FIG. 1  and  FIG. 2  are an exploded perspective view and an assembled perspective of the present invention respectively. The present invention provides a panel heat-dissipating device, which includes a heat-conducting base  1 , a vapor chamber  2 , and at least one fin assembly  3 . 
     The heat-conducting base  1  is formed into a flat plate and is made of heat-conducting materials such as aluminum, copper or the like. The bottom surface of the heat-conducting base  1  is a surface  10  to be heated to which an electronic heat-generating element  4  such as a central processing unit can be attached ( FIG. 5 ). The top surface of the heat-conducting base  1  is a heat-conducting surface  11 . With the heat-conducting surface  11  being thermally connected to the vapor chamber  2 , the heat absorbed by the heat-conducting base  1  can be conducted to the vapor chamber  2 . Further, the periphery or corners of the heat-conducting base  1  can be provided with a locking hole  12 . After associated fixing elements (not shown) are penetrated into the locking holes, the heat-conducting base  1  can be fixed to a circuit board (such as a main board) provided in the central processing unit. 
     The interior of the vapor chamber  2  is under vacuum and the periphery thereof is sealed. The inner wall of the vapor chamber has capillary structure. The interior of the vapor chamber is filled with a working fluid that is a heat-conducting element for conducting heat by means of the changes in liquid/vapor phases. The vapor chamber  2  is formed into an elongate and flat plate. A portion of the vapor chamber  2  is attached to the heat-conducting surface  11  of the heat-conducting base  1 , thereby generating a heat-conducting effect. The rest portion of the vapor chamber extends toward the lateral of the heat-conducting base  1 . In the present embodiment, the middle portion of the vapor chamber  2  is attached and fixed to the heat-conducting surface  11  of the heat-conducting base  1 . The other two elongate ends of the vapor chamber protrude and extend from the heat-conducting base  1 , so that the heat absorbed by the heat-conducting base  1  can be conducted to the middle portion of the vapor chamber  2 . Via the high heat-conducting effect of the vapor chamber  2 , the heat can be conducted from both ends of the vapor chamber  2 . 
     The fin assembly  3  is formed by means of arranging a plurality of fins  30  at intervals. Each of the fins  30  is bent to form a bending edge  300 . With reference to  FIGS. 3 and 4 , the bending edge  300  of each fin  30  can be used as a pitch of the transverse arrangement. After the bending edge  300  of each fin  30  is bent, the upside of the fin assembly  3  is formed into a recessed region  31 . The portion of the vapor chamber  2  extending from the heat-conducting base  1  is accommodated in the recessed region  31  to be attached to the bending edge  300  of each fin  30 , so that the fin assembly  3  is located below the vapor chamber  2 . The fin assembly and the heat-conducting base  1  are located on the same side of the vapor chamber  2 . As a result, the heat-dissipating device occupies less space in the height thereof. Therefore, it can be more suitable for the cases that the height and thickness thereof are restricted. 
     The connection among the heat-conducting base  1 , the vapor chamber  2  and the fin assembly  3  can be achieved by means of soldering, heat-conducting glue or heat-conducting adhesive, thereby fixing each element. 
     Therefore, with the above elements, the panel heat-dissipating device of the present invention can be obtained. 
     As shown in  FIG. 5 , when the heat-dissipating device is applied to an electronic heat-generating element  4  such as a central processing unit, the surface  10  to be heated of the heat-conducting base  1  is attached to the upper surface of the electronic heat-generating element  4  and is located in place by means of the locking holes  12  of the heat-conducting base  1 . The outmost fin  30  of the fin assembly  3  can be also formed into a locking piece  32  that is bent outwardly, so that screw elements such as bolts  41  can penetrate the locking pieces to be positioned on the circuit board  40 . The heat-dissipating device serves as a heat-conducting path by means of the transverse extension of the vapor chamber  2 . Especially, the heat-conducting base  1  is disposed below the middle section of the vapor chamber  2 , so that both ends of the vapor chamber  2  can be used as condensed ends and are connected to the fin assembly  3  respectively. In practice, the gap between the vapor chamber  2  and a circuit board  40  allows the fin assembly  3  to be disposed therein, so that the whole height of the heat-dissipating device gets close to the circuit board  40 , thereby reducing the space efficiently. Besides, in real practice we can reverse the heat-dissipating device by  180  degree, and let middle part of the vapor chamber  2  to attach directly with an electronic heat-generating element  4 . Hence, it also has the same effect as reducing the space. 
     According to the above, the present invention really achieves the desired objects and solves the drawbacks of prior art. Further, the present invention indeed has novelty and inventive steps, and thus conforms to the requirements for a utility model patent. 
     Although the present invention has been described with reference to the foregoing preferred embodiments, it will be understood that the invention is not limited to the details thereof. Various equivalent variations and modifications can still occur to those skilled in this art in view of the teachings of the present invention. Thus, all such variations and equivalent modifications are also embraced within the scope of the invention as defined in the appended claims.