Abstract:
An exemplary method of manufacturing a heat dissipation device includes, firstly, providing a heat pipe including a condenser section having a planar outer surface, and providing a heat sink including a supporting surface defining a guiding line. The guiding line has a width smaller than a width of the outer surface of the condenser section. Next, an amount solder is spread on the supporting surface along the guiding line to form a solder layer on the supporting surface. The solder layer has a size not larger than a size of the outer surface of the condenser section. Then the outer surface of condenser section of the heat pipe is attached to the solder layer on the supporting surface of the heat sink.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is a divisional application of patent application Ser. No. 12/558,602, filed on Sep. 14, 2009, entitled “HEAT DISSIPATION DEVICE WITH GUILDING LINES AND SOLDERED HEAT PIPES AND MANUFACTURING METHOD THEREOF,” which is assigned to the same assignee as the present application, and which is based on and claims priority from Chinese Patent Application No. 200910304299.9 filed in China on Jul. 13, 2009. The disclosures of patent application Ser. No. 12/558,602 and the Chinese Patent Application are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The disclosure relates to a manufacturing method of a heat dissipation device, and particularly to a manufacturing method of a heat dissipation device for dissipating heat generated by an electronic component. 
         [0004]    2. Description of Related Art 
         [0005]    Electronic components operating at high speed generate excessive heat which must be removed efficiently to ensure normal operation. Typically, a heat dissipation device attached to the electronic component provides such heat dissipation. 
         [0006]    A conventional heat dissipation device includes a heat sink and a heat pipe connected to the heat sink. The heat pipe is linear shaped and has a rectangular planar bottom surface for contacting a side surface of the heat sink. When the heat pipe is combined to the heat sink, a solder layer is spread on a portion of the side surface of heat sink by an operator for fixing the bottom surface of the heat pipe thereon. 
         [0007]    However, a position of the solder layer is decided by visual observation of the operator, and the solder layer usually has an irregular shape and an imprecise location. When the bottom surface of the heat pipe is attached to the heat sink, a part of the bottom surface of the heat pipe may directly contact a portion of the side surface without solder spread thereon and thus the connection between the heat pipe and the heat sink is faulty. Furthermore, a portion of the solder layer uncovered by the bottom surface of the heat pipe may melt during soldering and flow to other portions of the side surface uncovered by the bottom surface of the heat pipe, thereby contaminating the heat sink. This results in waste of the solder and trouble required to clean the contamination. 
         [0008]    It is thus desirable to provide a manufacturing method of a heat dissipation device which can overcome the described limitations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an isometric, assembled view of a heat dissipation device according to an exemplary embodiment. 
           [0010]      FIG. 2  is an exploded view of the heat dissipation device of  FIG. 1 . 
           [0011]      FIG. 3  is an enlarged view of a circled portion III of  FIG. 2 . 
           [0012]      FIG. 4  is a view schematically showing solder layers being formed on a supporting surface of the heat sink along guiding lines thereof. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Reference will now be made to the drawing figures to describe the present heat dissipation device and a manufacturing method thereof in detail. 
         [0014]      FIG. 1  illustrates a heat dissipation device for dissipating heat generated by an electronic component (not shown). The heat dissipation device includes a heat sink  10  and two heat pipes  20 . 
         [0015]    Referring to  FIG. 2 , each of the heat pipes  20  is tubular, and includes an evaporator section  22  and an opposite condenser section  24 . The condenser section  24  of each of the heat pipes  20  is linear shaped, and has a rectangular planar bottom surface  240 . 
         [0016]    The heat sink  10  includes a plurality of first fins  11  and a pair of second fins  12 . The first fins  11  are located at a central portion of the heat sink  10 , and the pair of second fins  12  are arranged at left and right sides of the first fins  11 , respectively. The first and second fins  11 ,  12  are arranged side by side along a left-to-right direction of the heat sink  10 . Each of the first and second fins  11 ,  12  includes a plate-shaped main body  120 , a bottom flange  122  extending leftwards and perpendicularly from a bottom side of the main body  120 , and a top flange  125  extending leftwards and perpendicularly from a top side of the main body  120 . A top side of a middle portion of each main body  120  in a front-to-rear direction is lower than top sides of front and rear portions of the main body  120 . Accordingly, a rectangular groove  18  is defined in a middle portion of the heat sink  10  between front and rear portions of the heat sink  10  after the first and second fins  11 ,  12  are stacked together. 
         [0017]    Each of the top flanges  125  includes two upper flange portions  124  formed at the top sides of the front and rear portions of the corresponding main body  120 , respectively, and a lower flange portion  126  formed at the top side of the middle portion of the corresponding main body  120 . The main bodies  120  of the first and second fins  11 ,  12  are parallel to and equally spaced from each other. Each of the top and bottom flanges  125 ,  122  has a width substantially equal to a distance between the main bodies  120  of neighboring fins  11 ,  12 . Each of the top flanges  125  extends perpendicularly from the top side of the main body  120  to contact the main body  120  of a neighboring fin  11 ,  12 . Thus the upper flange portions  124  of the top flanges  125  cooperatively form two planar top surfaces  16  at top sides of the front and rear portions of the heat sink  10 , respectively. The lower flange portions  126  of the top flanges  125  cooperatively form a supporting surface  19  at a top side of the middle portion of the heat sink  10 . In addition, the bottom flanges  122  of the fins  11 ,  12  cooperatively form a planar bottom surface  14  at a bottom side of the heat sink  10 . 
         [0018]    Referring to  FIGS. 2 and 3 , front and rear cutouts  150 ,  151  are defined in front and rear ends of each of the lower flange portions  126  of the first fins  11 , respectively. The front and rear cutouts  150 ,  151  of each of the lower flange portions  126  are parallel to each other. Each of the cutouts  150 ,  151  extends along a bending direction of the lower flange portion  126 , and is perpendicular to the main body  120 . Each of the cutouts  150 ,  151  has a length in the left-to-right direction substantially equal to the width of the lower flange portion  126 , and a depth slightly smaller than a thickness of the lower flange portion  126 . Thus each of the cutouts  150 ,  151  extends through left and right sides of the lower flange portion  126 . The front cutouts  150  of the lower flange portions  126  of each two neighboring first fins  11  are communicated with each other. More specifically, for each two neighboring first fins  11 , a right end of the front cutout  150  of a left first fin  11  connects a left end of the front cutout  150  of a right first fin  11 . Thus a first guiding line  15  is formed at a front end of the guiding surface  19  of the heat sink  10  by the front cutouts  150  of the lower flange portions  126  after the first fins  11  are stacked together. Similarly, the rear cutouts  151  of the lower flange portions  126  of each two neighboring first fins  11  are communicated with each other, and a second guiding line  15  is formed at a rear end of the guiding surface  19  of the heat sink  10  by the rear cutouts  151  of the lower flange portions  126  after the first fins  11  are stacked together. 
         [0019]    When the heat sink  10  is assembled, the first fins  11  are arranged at the central portion of the heat sink  10  side by side, and the second fins  12  are arranged at the left and right sides of the first fins  11 , respectively. The first and the second guiding lines  15  are accordingly formed by the front and rear cutouts  150 ,  151  of the first fins  11  at the front and rear ends of the guiding surface  19 , respectively. Each of the guiding lines  15  extends straightly as does the bottom surface  240  of the condenser section  24  of a corresponding one of the heat pipes  20 , and each guiding line  15  has a width much smaller than a width of the bottom surface  240  of the condenser section  24  of the corresponding heat pipe  20 . Since the second fins  12  do not define cutouts therein and the lower flange portions  126  of the second fins  12  each have completely smooth top and bottom faces, each of the guiding lines  15  forms closed ends  152  at left and right ends thereof, respectively. That is, each of the guiding lines  15  does not extend through the left and right sides of the heat sink  10 , and the closed ends  152  of each guiding line  15  are adjacent to the left and right sides of the heat sink  10 , respectively. 
         [0020]    Referring to  FIG. 4 , an amount of solder is spread on the supporting surface  19  along the first and second guiding lines  15  to form two straight rectangular solder layers  30  respectively. Each of the solder layers  30  has a size not larger than a size of the bottom surface  240  of the corresponding condenser section  24 . In this embodiment, the size of each of the solder layers  30  is substantially equal to the size of the bottom surface  126  of the condenser section  24 . Then the heat pipes  20  are positioned on the supporting surface  19  of the heat sink  10 , with the bottom surfaces  240  of the condenser sections  24  contacting the solder layers  30 , respectively. Finally the heat pipes  20  are soldered to the heat sink  10  by heating the solder layers  30 . 
         [0021]    Since the guiding lines  15  are provided on the supporting surface  19  of the heat sink  10 , the solder can be conveniently spread on correct positions of the supporting surface  19  along the guiding lines  15  to form the straight, rectangular solder layers  30  on the supporting surface  19 . Thus the heat pipes  20  can be accurately mounted to the solder layers  30  of the supporting surface  19 , and good contact is formed between the heat pipes  20  and the supporting surface  19 . Furthermore, since the guiding lines  15  form the closed ends  152  at the left and right ends thereof, when the solder is heated, molten solder will not flow from the guiding lines  15  to the left and right sides of the heat sink  10  to contaminate the heat sink  10 . Moreover, the molten solder has a tendency to expand and overflow when heated. The guiding lines  15  can provide a space for receiving the expanded molten solder therein, thereby avoiding the molten solder flowing from the solder layer  30  to other portions of the supporting surface  19  to contaminate the heat sink  10 . Thus, the solder between the heat pipes  20  and the heat sink  10  forms a firm connection between the heat pipes  20  and the heat sink  10 . 
         [0022]    It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.