Patent Publication Number: US-2011056658-A1

Title: Heat pipe assembly and heat dissipation device having the same

Description:
BACKGROUND 
     The present invention relates to heat dissipation devices, and particularly to a heat pipe assembly including a number of heat pipes and a fixing structure which enables evaporating sections of the heat pipes being parallel to and adjoining with each other, and a heat dissipation device including such a heat pipe assembly. 
     With the development of computer technologies, electronic elements run at high speed and therefore generate large amounts of heat. In order to keep the electronic elements operating at a normal temperature, the heat must be quickly and efficiently removed from the electronic elements by a heat dissipation device. Conventionally, the heat dissipation device includes a heat pipe which uses a gas-liquid phase transition technology to dissipate the heat generated by the electronic elements. 
     However, in order to increase the heat dissipation efficiency of the heat dissipation device, a number of heat pipes are included in the heat dissipation device. Currently, the heat pipes are secured to a base seat or a heat conducting seat of the heat dissipation device by welding method. Also, evaporation sections of the heat pipes may be embedded in the grooves defined on the base seat or the heat conducting seat of the heat dissipation device and secured to the base seat or the heat conducting seat. However, the welding process is not easy to perform and the welded heat dissipation device has an unattractive appearance. When the evaporation sections of the heat pipes are embedded in the groves of the base seat or a heat conducting seat, the evaporation sections must be spaced from each other and can not be tightly adjoin with each other, whereby the evaporating sections can not be gathered to thermally contact with a surface of a heat generating electronic element. As a result, outermost two of the heat pipes can not be sufficiently used, thereby the heat dissipation device having low heat dissipation efficiency. 
     Therefore, what is needed is a heat pipe assembly and a heat dissipation device including such a heat pipe assembly, thereby overcoming the above-described problems. 
     BRIEF SUMMARY 
     The present invention provides a heat pipe assembly and a heat dissipation device including the heat pipe assembly. The heat pipe assembly includes a number of evaporation sections and a molded fixing seat. By the fixing structure, the evaporating sections of the heat pipe assembly are parallel to and adjoin with each other, whereby heat absorb surfaces of the evaporating sections are coplanar and adjoin with each other to thereby form a large-area heat absorbing surface to thermally contact with a heat generating electronic element. 
     The heat pipe assembly includes a number of heat pipes and a fixing seat engaging with evaporating sections of the heat pipes. Each of the heat pipes includes an evaporating section and at least a condensing section. A bottom of the evaporation section of each of the heat pipes is flat and has a flat heat absorbing surface. The evaporating sections of the heat pipes are parallel to and adjoin with each other, whereby the heat absorbing surfaces thereof are coplanar and adjoin with each other. A top surface of the evaporating section of each of the heat pipes has a top edge. The fixing seat has an integral structure and combines with the top edges of the evaporating sections of the heat pipes, thereby facilitating the heat absorbing surfaces of the evaporating sections of the heat pipes being coplanar and adjoining with each other. 
     A heat dissipation device including above-described heat pipe assembly is provided. The heat dissipation device further comprises a number of heat conducting fins disposed on the condensing sections of the heat pipes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
         FIG. 1  is a schematic, isometric view of a heat pipe assembly, according to a first embodiment of the present disclosure. 
         FIG. 2  is a schematic, isometric view of the heat pipe assembly from a visual angle different from  FIG. 1 . 
         FIG. 3  is a partially, cross-sectional view of  FIG. 1 . 
         FIG. 4  is a partially, cross-sectional view of  FIG. 2 . 
         FIG. 5  is a partially, cross-sectional view of a heat pipe assembly, according to a second embodiment of the present disclosure. 
         FIG. 6  is a partially, exploded view of a heat dissipation device of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  are schematic, isometric views of a heat pipe assembly of the present invention in different visual angles. The heat pipe assembly includes a number of heat pipes  1  and a fixing seat  2 . 
     Each of the heat pipes  1  is heat conducting element and includes a vacuous tubular body, a capillary structure disposed inside the tubular body and a working fluid contained in the tubular body and soaking the capillary structure. The tubular body of each of the heat pipes  1  is an integral structure and has a certain length. The heat pipes  1  each include an evaporating section  10  and at least a condensing section  11  connected with the evaporating section  10 . In the present embodiment, each of the heat pipes  1  has a U-shaped configuration, a bottom portion of the U-shaped configuration is the evaporating section  10 , and two lateral portions of the U-shaped configuration are two condensing sections  11 . A curved section  12  is connected between the evaporation section  10  and each condensing section  11 . Thus, the evaporation section  10 , two condensing sections  11  and two curved sections  12  cooperatively form each of the heat pipes  1 . In addition, a bottom of the evaporation section  10  of each of the heat pipes  1  is flat and has a flat heat absorbing surface  100 . Evaporating sections  10  of the heat pipes  1  are parallel to and adjoin with each other, whereby the heat absorb surfaces  100  of the evaporating sections  10  are coplanar and adjoin with each other to thereby form a large-area heat absorbing surface. 
     The fixing seat  2  has an integral configuration and is made of plastic materials, such as, PC, PP, PE, PU or the like. The fixing seat  2  is made by integral molding process, e.g., injection molding, gel-casting molding, perfusion molding, die casting, dipping and so on. The fixing seat  2  engages with the evaporating sections  10  of the heat pipes  1 . Referring to  FIGS. 3 and 4 , the fixing seat  3  has a base  20 , a top surface the evaporation section  10  of each of the heat pipes  1  has a top edge  101 . The base  20  has a bottom surface combining with the top edge  101  of the top surface of the evaporation section  10  of each of the heat pipes  1 , whereby the evaporation sections  10  of the heat pipes  1  can be secured to enable the heat absorbing surfaces  100  of the evaporation sections  10  of the heat pipes  1  being parallel to and adjoining with each other. As a result, the heat absorbing surfaces  100  are coplanar and adjoin with each other to form a large-area surface, thereby facilitating thermally contacting with heat-generating sources (not shown). In addition, in order to increase a contact area between the fixing seat  2  and the heat pipes  1 , the fixing seat  2  further includes two reinforcement portions  21  respectively extending outwardly from two lateral ends of the base  20 . The reinforcement portion  21  located at right side of the base  20  of the fixing seat  2  encloses all of the curved sections  12  of the heat pipes  1  located at right side of the base  20  of the fixing seat  2 ; the reinforcement portion  21  located at left side of the base  20  of the fixing seat  2  encloses all of the curved sections  12  of the heat pipes  1  located at left side of the base  20  of the fixing seat  2 ; thereby enhancing a bonding strength between the fixing seat  2  and the heat pipes  1 . 
     In order to ensure the evaporation sections  10  of the heat pipes  1  being parallel to and adjoining with each other, a cross section of each of the evaporation sections  10  is square or rectangular, as shown in  FIG. 4 . Thus, each of the evaporation sections  10  has two vertical lateral walls  102 , and the lateral walls  102  of adjacent evaporation sections  10  tightly joint with each other. As a result, the evaporation sections  10  of the heat pipes  1  can be gathered together to facilitate the evaporation sections  10  of the heat pipes  1  exchanging heat, whereby the heat pipes  1  can be evenly heated. Furthermore, as shown in  FIG. 4 , the curved sections  12  of the heat pipes  1  are radially arranged relative to an assembly of the evaporation sections  10  of the heat pipes, that is, adjacent curved sections  12  are angled with each other, whereby the condensing sections  11  of the heat pipes  1  are spaced from each other. In the illustrated embodiment, the condensing sections  11  of the heat pipes  1  are vertical to the evaporating sections  10  of the heat pipes  1 . 
     Referring to  FIG. 5 , the fixing seat  2  includes two enclosing portions  200  extending downwardly from the base  20  to respectively enclose the lateral walls  102  of the two outermost heat pipes  1 , thereby enhancing the bonding strength among the evaporating sections  10  of the heat pipes  1 . The enclosing portions  200  each include a bottom edge  201  not protrude downwardly relative to the heat absorbing surfaces  100 . In the present embodiment, the bottom edges  201  of the enclosing portions  200  are coplanar with the heat absorbing surfaces  100 . 
     Referring to  FIG. 6 , a heat sink having the above-described heat pipe assembly of  FIG. 1  is illustrated. The heat sink includes a number of heat conducting fins  3 . The heat conducting fins  3  are parallel to and equidistantly spaced from each other. Two lateral portions of each of the heat conducting fins  3  defines a number of through holes  30  to allow the condensing sections  11  of the heat pipes  1  passing therethrough. An annular protruded flange  31  extends upwardly from an circumference edge defining each of the through holes  30  to enable adjacent heat conducting fins  3  spaces a certain distance. Thus, the heat conducting fins  3  define a number of airflow passages to increase heat dissipation efficiency. In assembly, the condensing sections  11  of the heat pipes  1  respectively extend the through holes  30  of the heat conducting fins  3  to enable an assembly of the heat conducting fins  3  locating over the evaporation sections  10  of the heat pipes  1 . 
     Therefore, the heat pipes  1  and the fixing seat  2  cooperatively constitute the heat pipe assembly; the heat pipe assembly and the heat conducting fins  3  are construct the heat sink. 
     The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including configurations ways of the recessed portions and materials and/or designs of the attaching structures. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.