Abstract:
An exemplary plate-type heat pipe includes a condensing plate, an evaporating plate and a spherical supporting. The evaporating plate engages with the condensing plate to define a hermetic container. Working fluid is contained in the container. The supporting portion in the container is sandwiched between the condensing plate and the evaporating plate and abuts against the condensing plate and the evaporating plate.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to plate-type heat pipes, and more particularly, to a plate-type heat pipe having stable and reliable performance and a method for manufacturing such plate-type heat pipe. 
         [0003]    2. Description of Related Art 
         [0004]    Generally, plate-type heat pipes are used to absorb heat generated by electronic components and transfer and/or dissipate the heat elsewhere. A typical plate-type heat pipe includes a plate-shaped container, a wick structure formed on inner surfaces of the container, and working fluid sealed inside the container. The container is prone to be deformed when it is pressed accidentally or when the working fluid is vaporized, thereby adversely affecting the stable performance of the plate-type heat pipe. 
         [0005]    What is needed, therefore, is a plate-type heat pipe which can overcome the limitations described, and a method for manufacturing such a plate-type heat pipe. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is an exploded, isometric view of a plate-type heat pipe in accordance with an embodiment of the present disclosure. 
           [0007]      FIG. 2  is an assembled, side cross-sectional view of the plate-type heat pipe of  FIG. 1 . 
           [0008]      FIG. 3  is a side cross-sectional view showing a first mold accommodating a condensing plate of the plate-type heat pipe of  FIG. 1 . 
           [0009]      FIG. 4  is similar to  FIG. 3 , but showing a first wick structure of the plate-type heat pipe of  FIG. 1  being formed on the condensing plate. 
           [0010]      FIG. 5  is an isometric view of a first mold portion of a second mold, which is used for forming a second wick structure of the plate-type heat pipe of  FIG. 1 . 
           [0011]      FIG. 6  is an isometric view of a second mold portion of the second mold, showing the second mold portion inverted. 
           [0012]      FIG. 7  is a side cross-sectional view showing the first and second mold portions of the second mold coupled together and accommodating an evaporating plate of the plate-type heat pipe of  FIG. 1 . 
           [0013]      FIG. 8  is similar to  FIG. 7 , but showing a second wick structure of the plate-type heat pipe of  FIG. 1  being formed on the evaporating plate. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    A method for manufacturing a plate-type heat pipe in accordance with an embodiment of the present disclosure includes steps of: a) providing a first metallic sheet, a second metallic sheet, and a supporting portion; b) arranging the supporting portion between the first metallic sheet and the second metallic sheet; and c) welding the first and second metallic sheets together, thereby obtaining a hermetical container, the supporting portion abutting against and connecting with the first and second metallic sheets. Exemplary details of the method are given below. 
         [0015]    Referring to  FIGS. 1-2 , in a typical application, the method is used to manufacture a plate-type heat pipe which includes an elongated condensing plate  11 , a tray-shaped evaporating plate  13 , a first wick structure  12 , a second wick structure  14 , and a plurality of supporting portions  15 . The condensing plate  11  hermetically contacts the evaporating plate  13 . The evaporating plate  13  is adapted for absorbing heat generated by one or more components (not shown) such as electronic devices. The condensing plate  11  dissipates heat, transferred from the evaporating plate  13 , to the ambient environment. The first wick structure  12  is adhered on an inner surface of the condensing plate  11 . The second wick structure  14  is adhered on an inner surface of the evaporating plate  13 . Each of the supporting portions  15  is a sphere and abuts against the inner surfaces of the condensing plate  11  and the evaporating plate  13 , respectively. The condensing plate  11 , the evaporating plate  13  and the supporting portions  15  are formed from metallic material which can be soldered and which transfers heat well. In this embodiment, the condensing plate  11 , the evaporating plate  13  and the supporting portions  15  are made of copper. 
         [0016]    The evaporating plate  13  includes a rectangular heat absorbing portion  131 , four sidewalls  133 , and two extending portions  135 . The sidewalls  133  perpendicularly extend upwardly from four edges of the heat absorbing portion  131 . The extending portions  135  extend outwardly along opposite horizontal directions from top portions of two opposite sidewalls  133 , respectively. The extending portions  135  are perpendicular to the sidewalls  133 . Top surfaces of the extending portions  135  and top ends of two corresponding sidewalls  133  interconnecting the extending portions  135  are all coplanar with one another. 
         [0017]    The second wick structure  14  includes a first wick portion  141  and four second wick portions  143 . The first wick portion  141  is adhered on an inner surface of the heat absorbing portion  131 . The second wick portions  143  are adhered on inner surfaces of the sidewalls  133 , respectively. The top surfaces of the extending portions  135  and the top ends of the two corresponding sidewalls  133  hermetically connect a periphery of a bottom surface of the condensing plate  11 . Four lateral side edges of the first wick structure  12  connect with inside surfaces of top ends of the second wick portions  143  of the second wick structure  14 , respectively. The supporting portions  15  extend through the first wick structure  12  and the first wick portions  141  to directly abut against the condensing plate  11  and the heat absorbing portion  131  of the evaporating plate  13 , respectively. 
         [0018]    Referring also to  FIGS. 3-4 , the first wick structure  12  is sintered copper powder made in a first mold  20 , and the second wick structure  14  is sintered copper powder made in a second mold  40 , as shown in  FIGS. 5-8 . 
         [0019]    The first mold  20  includes a first mold portion  21 , and a second mold portion  23  matching with the first mold portion  21 . The first mold portion  21  includes a top plate  213  and four elongated, spaced pressing walls  215  extending perpendicularly downwardly from an inner surface of the top plate  213 . The second mold portion  23  is a rectangular container, and includes a supporting plate  231  and four baffling plates  233  extending perpendicularly upwardly from four edges of the supporting portion  231 . A space (not labeled) is thus defined among the baffling plates  233  over the supporting plate  231 . 
         [0020]    The condensing plate  11  is received in the second mold portion  23 , with lateral side edges of the condensing plate  11  abutting against inner surfaces of the baffling plates  233 . Top ends of the baffling plates  233  protrude up beyond the condensing plate  11 . The first mold portion  21  is coupled to the second mold portion  23 , with the pressing walls  215  received in the space and engaging with inner sides of the baffling plates  233 , respectively. The top ends of the baffling plates  233  abut against a periphery of the inner surface of the top plate  213 . In such a state, bottom ends of the pressing walls  215  contact peripheral portions of the condensing plate  11 . The pressing walls  215 , the top plate  213  and the condensing plate  11  cooperatively define a rectangular first receiving chamber  30 . 
         [0021]    The copper powder is filled in the first receiving chamber  30  and is sintered to form the first wick structure  12  on a main central portion of the inner surface of the condensing plate  11 . 
         [0022]    The second mold  40  includes a first mold portion  41  and a second mold portion  43 . Referring to  FIG. 5 , the first mold portion  41  includes an engaging plate  413 , and a cuboid protruding portion  415  protruding from a central portion of the engaging plate  413 . Therefore each of opposite lateral ends of the engaging plate  413  exposed beyond the protruding portion  415  forms a first pressing portion  414 , and each of two opposite front and rear ends of the engaging plate  413  exposed beyond the protruding portion  415  forms a second pressing portion  416 . A size of each first pressing portion  414  is larger than that of the corresponding extending portion  135  of the evaporating plate  13 . A size of each second pressing portion  416  is larger than that of the top end of the corresponding sidewall  133 . A plurality of cylindrical receiving holes  4151  is defined in the protruding portion  415  to receive the supporting portions  15  therein. A height of the protruding portion  415  is less than a height of the sidewalls  133  of the evaporating plate  13 . A length of the protruding portion  415  is less than a distance between the two corresponding sidewalls  133  of the evaporating plate  13 . A width of the protruding portion  415  is less than a distance between the two corresponding sidewalls  133  of the evaporating plate  13 . A diameter of each receiving hole  4151  is substantially equal to or slightly greater than a diameter of each supporting portion  15 , and a depth of the receiving hole  4151  is less than the diameter of the supporting portion  15 . 
         [0023]    As shown in  FIG. 6 , the second mold portion  43  includes a supporting plate  431 , two first extending plates  433  and two second extending plates  435 . The first extending plates  433  are elongated, parallel to each other and extend upwardly from two opposite front and rear ends of the supporting plate  431 . The second extending plates  435  are elongated, parallel to each other and extend upwardly from two opposite left and right lateral ends of the supporting plate  431 . The second extending plates  435  perpendicularly interconnect the first extending plates  433 . A height of the second extending plates  435  is less than that of the first extending plates  433 . The difference between the heights of the second extending plates  435  and first extending plates  433  is generally equal to a thickness of the extending portions  135  of the evaporating plate  13 . The supporting plate  431 , the first extending plates  433  and the second extending plates  435  cooperatively define a receiving chamber  437  to receive the evaporating plate  13 . 
         [0024]    Referring to  FIGS. 6 and 7 , to form the second wick structure  14 , the evaporating plate  13  is received in the receiving chamber  437  of the second mold portion  43  of the second mold  40 , with the heat absorbing portion  131  of the evaporating plate  13  contacting the supporting plate  431  of the second mold portion  43 . Bottom ends (as viewed in  FIG. 7 ) of the second extending plates  435  abut against the extending portions  135  of the evaporating plates  13 , respectively; and inner sides of the second extending plates  435  contact the two sidewalls  133  from which the extending portions  135  extend. The other two sidewalls  133  contact inner sides of the first extending plates  433 , respectively. Bottom ends (as viewed in  FIG. 7 ) of the extending portions  135 , said other two sidewalls  133 , and the first extending plates  433  are all coplanar with one another. 
         [0025]    Referring to  FIGS. 5 and 7 , the supporting portions  15  are received in the receiving holes  4151  of the protruding portion  415  of the first mold portion  41 . 
         [0026]    Referring to  FIG. 7 , the first mold portion  41  and the second mold portion  42  are then coupled together. In this state, the first pressing portions  414  of the first mold portion  41  contact the extending plates  135  of the evaporating plate  13 , respectively. The second pressing portions  416  press the bottom ends of said other two sidewalls  133  and the first extending plates  433 . The protruding portion  415  is spaced from the heat absorbing portion  131 , while the supporting portions  15  contact the heat absorbing portion  131 . The sidewalls  133  of the evaporating plate  13  surround and are spaced from the protruding portion  415 . A second receiving chamber  50  is thus defined between the evaporating plate  13  and the first mold portion  41 . 
         [0027]    Referring to  FIG. 8 , copper powder is then filled in the second receiving chamber  50  and is sintered to form the second wick structure  14 . The supporting portions  15  also connect with the second wick structure  14  by the sintering of the copper powder. In one embodiment, the supporting portions  15  become integrally connected with the second wick structure  14 . 
         [0028]    After the first wick structure and the second wick structure  14  are formed, the first mold  20  and the second mold  40  are opened to obtain the condensing plate  11  and the evaporating plate  13 . The condensing plate  11  and the evaporating plate  13  are then attached together by welding. The condensing plate  11  and evaporating plate  13  are brought into contact with each other, and then subjected to high temperature and high pressure for a period of time. As a result, the supporting portions  15  penetrate through the first wick structure  12 , with opposite ends of the supporting portions  15  thereby abutting against both the condensing plate  11  and the evaporating plate  13 . 
         [0029]    It is to be understood, however, that even though numerous characteristics and advantages of various 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 disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.