Abstract:
A thermal module with heat pipe is disclosed to include a heat-dissipation plate, which has an accommodation groove that accommodates a heat pipe that is bonded to the accommodation groove with a bonding glue, and at least one retaining groove formed in the accommodation groove for retaining the bonding glue to prevent overflow of the bonding glue during its fluid state so as to improve the yield rate of the fabrication of the thermal module with heat pipe, avoid a further follow-up process, facilitate the quality control, save the cost, and keep a good looking of the finished product.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a thermal module and more particularly, to a thermal module with heat pipe. 
         [0003]    2. Description of Related Art 
         [0004]    For a regular electronic product, such as a personal computer, a server, or a video player, usually installs at least one heat generating electronic device such as, a CPU, a graphic chip, or the like, therein. It is necessary to provide a thermal module in the electronic product to carry heat away from the internal heat generating electronic device, preventing accumulation of heat that may result in malfunctioning of the heat generating electronic device or cause damage to surrounding system chips. The thermal module may be formed of a heat-dissipation fins or a heat-dissipation fan or the like. 
         [0005]    There is known a thermal module design that has a heat pipe bonded to a heat-dissipation plate. The bonding between the heat pipe and the heat-dissipation plate is achieved by means of the application of a heat-dissipation solder paste. This design of thermal module with heat pipe uses the heat-dissipation plate to absorb heat from the heat source, for enabling the absorbed heat energy to be transferred to the heat pipe by the heat-dissipation solder paste and then carried away by the heat pipe. The heat pipe has a fluid (for example, water) filled therein. The fluid is changed to steam when heated by the heat energy transferred from the heat-dissipation plate through the heat-dissipation solder paste, and the steam immediately flows to the remote end of the heat pipe to make a heat exchange. After the heat exchange, the steam is changed to the fluid state, which immediately flows back to the proximity end of the heat pipe for another heat exchange cycle. This procedure is repeated again and again, and therefore heat energy is continuously carried away from the heat source. 
         [0006]    According to the aforesaid conventional technique, the heat pipe is directly mounted in a groove on the heat-dissipation plate and fixedly secured thereto by means of a heat-dissipation solder paste. This design has a surface contact between the heat pipe and the heat-dissipation plate, increasing the heat absorbing surface area of the heat pipe. 
         [0007]    However, when bonding the heat pipe to the heat-dissipation plate with a heat-dissipation solder paste, the control of the flowing direction of the applied fluid state heat-dissipation solder paste is not easy because many factors such as the amount and purity of the tin solder applied, the manufacturing process employed, the machine tools used, or the positioning status of the heat-dissipation heat plate with the tin solder and the heat pipe in the soldering stove may affect the flowing direction of the fluid state tin solder (heat-dissipation solder paste). 
         [0008]    Therefore, an overflow of the heat-dissipation solder paste may occur (the heat-dissipation solder paste may flow over the heat-dissipation plate and the heat pipe), resulting in a low yield rate of the fabrication and a bad looking of the finished thermal module with heat pipe. Further, when an overflow of the heat-dissipation solder paste occurred, a further follow-up procedure is necessary, thereby increasing the cost. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a thermal module with heat pipe that eliminates the drawback of the aforesaid conventional design. 
         [0010]    According to the present invention, the thermal module with heat pipe is comprised of a heat-dissipation plate and a heat pipe. 
         [0011]    The heat-dissipation plate has a top surface, a bottom surface, and an accommodation groove formed in the top surface of the heat-dissipation plate. The heat pipe is accommodated in the accommodation groove of the heat-dissipation plate by a bonding glue. 
         [0012]    The main feature of the present invention is that the heat-dissipation plate further has at least one retaining groove formed in the accommodation groove. 
         [0013]    After mounting of the heat pipe in the accommodation groove of the heat-dissipation plate, the bonding glue will flow in between the heat pipe and the heat-dissipation plate during its fluid state. However, it is not necessary to consider the flowing direction or overflow of the bonding glue. Because the accommodation groove of the heat-dissipation plate has at least one retaining groove in it that prevent overflow of the bonding glue, i.e., each retaining groove works as detaining means to retain excessive amount of the bonding glue when the bonding glue is forced outwards toward the two distal ends of the accommodation groove by the pressure of the heat pipe upon insertion of the heat pipe into the accommodation groove. Because the present invention prevents overflow of the bonding glue, the yield rate of the fabrication of the thermal module with heat pipe according to the present invention is high, and no further follow-up processing process is necessary after bonding of the heat pipe to the heat-dissipation plate, i.e., the present invention greatly improves the quality control and saves the cost. Further, because the present invention prevents overflow of the bonding glue, the finished thermal module with heat pipe has a nice outer appearance. 
         [0014]    Further, the bonding glue can be a heat-dissipation solder paste, adhesive, or any suitable bonding agent capable of bonding the heat pipe to the heat-dissipation plate. When a heat-dissipation solder paste is used, the condition of the aforesaid “overflow” is called “overflow of tin solder”. 
         [0015]    Further, the accommodation groove can be fitted the heat pipe in shape. For example, the accommodation groove can be a straight groove, and the heat-pipe can be a straight pipe fitting the straight accommodation groove. Alternatively, the accommodation groove can be a curved groove, and the heat-pipe can be a curved pipe fitting the curved accommodation groove. 
         [0016]    Further, the number of the at least one retaining groove can be two. In this case, the two retaining grooves are formed near the two distal ends of the accommodation groove respectively. When the bonding glue is flowing toward the two distal ends of the accommodation groove, the two retaining grooves retain the bonding glue, preventing overflow. 
         [0017]    In an alternate form of the present invention, the thermal module with heat pipe is comprised of a heat-dissipation heat plate and at least two heat pipes. 
         [0018]    The heat-dissipation heat plate has a top surface, a bottom surface, and at least two accommodation grooves formed in the top surface. The at least two heat pipes are respectively accommodated in the at least two accommodation grooves of the heat-dissipation plate by a bonding glue. 
         [0019]    Similarly, the heat-dissipation plate further has at least one retaining groove formed in at least one of the at least two accommodation grooves to retain the applied bonding glue, preventing overflow of the bonding glue. 
         [0020]    Further, the number of the at least one retaining groove can be two, and the two retaining grooves are formed near the two distal ends of at least one of the at least two accommodation grooves respectively. 
         [0021]    Further, the number of the at least one retaining groove can be two, and the two retaining grooves are formed in the at least two accommodation grooves respectively. In this design, the two retaining grooves of the at least two accommodation grooves are at the same side in the at least two accommodation grooves and are connected to one another. 
         [0022]    Further, the number of the at least one retaining grooves can be four, and the four retaining grooves are respectively disposed in the at least two accommodation grooves near the two distal ends of the at least two accommodation grooves. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is an exploded view of a thermal module with heat pipe in accordance with a first embodiment of the present invention. 
           [0024]      FIG. 2  is a sectional assembly view of the thermal module with heat pipe in accordance with the first embodiment of the present invention. 
           [0025]      FIG. 3  is perspective view of a thermal module with heat pipe in accordance with a second embodiment of the present invention. 
           [0026]      FIG. 4  is an exploded view of a thermal module with heat pipe in accordance with a third embodiment of the present invention; 
           [0027]      FIG. 5  is an exploded view of a thermal module with heat pipe in accordance with a fourth embodiment of the present invention. 
           [0028]      FIG. 6  is a perspective view of a thermal module with heat pipe in accordance with a fifth embodiment of the present invention. 
           [0029]      FIG. 7  is an exploded view of a thermal module with heat pipe in accordance with a sixth embodiment of the present invention. 
           [0030]      FIG. 8  is an exploded view of a thermal module with heat pipe in accordance with a seventh embodiment of the present invention. 
           [0031]      FIG. 9  is an exploded view of a thermal module with heat pipe in accordance with an eighth embodiment of the present invention. 
           [0032]      FIG. 10  is an exploded view of a thermal module with heat pipe in accordance with a ninth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0033]    Referring to  FIGS. 1 and 2 , a thermal module with heat pipe in accordance with a first embodiment of the present invention is shown. The thermal module  1  includes a heat-dissipation plate  11 , a bonding glue  13 , and a heat pipe  12 . 
         [0034]    The heat-dissipation plate  11  has a top surface  114 , a bottom surface  115  opposite to the top surface  114 , an accommodation groove  111  formed in the top surface  114 , and two transverse retaining grooves  112  formed in the accommodation groove  111  near the two distal ends of the accommodation groove  111 . The heat pipe  11  is accommodated in the accommodation groove  111  by the bonding glue  13 . 
         [0035]    In this embodiment, the bottom surface  115  of the heat-dissipation plate  11  is attached to a heat generating electronic device  15 . The heat generating electronic device  15  can be a CPU, a graphic chip, a network processing chip, a RAID chip, or the like. According to this embodiment, the heat generating electronic device  15  is a CPU. The heat-dissipation plate  11  and the heat pipe  12  according to this embodiment are made of copper for the advantage of high coefficient of heat transfer. Aluminum or any of a variety of other equivalent materials may be used as a substitute. Further, the bonding glue  13  can be obtained from any of a variety of adhesives capable of bonding the heat pipe  12  to the heat-dissipation plate  11 . According to this embodiment, the bonding glue  13  is a heat-dissipation solder paste. 
         [0036]    Further, the shape of the accommodation groove  111  of the heat-dissipation plate  11  fits the shape of the heat pipe  12 , i.e., the accommodation groove  111  is a straight groove fitting the straight heat pipe  12 . Further, the heat pipe  12  is a round pipe. The accommodation groove  111  has a semicircular cross section. When the heat pipe  12  is bonded to the accommodation groove  111  by the bonding glue  13  (heat-dissipation solder paste), the heat pipe  12  and the heat-dissipation plate  11  are matched perfectly, providing a surface contact and increasing the heat absorbing surface area of the heat pipe  12 . 
         [0037]    After bonding of the heat pipe  12  to the accommodation groove  111  of the heat-dissipation plate  11  by the bonding glue  13  (heat-dissipation solder paste), the desired thermal module is thus obtained. During application, the heat-dissipation plate  11  absorbs heat energy from the heat generating electronic device  15  and transfers absorbed heat energy to the heat pipe  12  for enabling the heat pipe  12  to carry heat energy away from the heat-dissipation plate  12 . The heat dissipation work of the heat pipe  12  is of the known art, no further detailed description in this regard is necessary. 
         [0038]    When accommodating the heat pipe  12  in the accommodation groove  111  of the heat-dissipation plate  11 , the bonding glue  13  (heat-dissipation solder paste) is flowing in the accommodation groove  111  between the heat-dissipation plate  11  and the heat pipe  12  during its fluid state. Thereafter, the bonding glue  13  (heat-dissipation solder paste) is cooled down and hardened to affix the heat pipe  12  to the heat-dissipation plate  11 . 
         [0039]    According to the present invention, it is unnecessary to consider the flowing direction or overflow of the bonding glue  13  during the fluid state of the bonding glue  13 . Because the accommodation groove  111  is a straight groove having a semicircular cross section and because the two transversely extending retaining grooves  112  are disposed near the two distal ends of the accommodation groove  111 , the retaining grooves  112  prevent overflow of the bonding glue  13 , i.e., the retaining grooves  112  work as detaining means to retain excessive amount of the bonding glue  13  when the bonding glue  13  is forced outwards toward the two distal ends of the accommodation groove  111  upon insertion of the heat pipe  12  into the accommodation groove  111 . Because the invention prevents overflow of the bonding glue  13 , the yield rate of the present invention is high, and no further follow-up processing process is necessary, i.e., the invention greatly improves the quality control and saves the cost. Further, because the invention prevents overflow of the bonding glue  13 , the finished thermal module with heat pipe has a nice outer appearance. 
         [0040]      FIG. 3  illustrates a thermal module with heat pipe in accordance with a second embodiment of the present invention. This embodiment is substantially similar to the aforesaid first embodiment with the exception of the use of a top cover  14  that is covered on the heat-dissipation plate  11  over the heat pipe  12 . 
         [0041]    According to this embodiment, the top cover  14  has a bottom surface  141  abutted to the top surface  114  of the heat-dissipation plate  11 , and an accommodation groove  142  formed in the bottom surface  141  and fitting the shape of the heat pipe  12  and accommodated the heat pipe  12 . 
         [0042]    According to this embodiment, the top cover  14  is made of copper. Further, the top cover  14  can be made having radiation fins to facilitate dissipation of heat. This second embodiment not only achieves the various effects of the aforesaid first embodiment but also enhances the heat dissipation efficiency. 
         [0043]      FIG. 4  is an exploded view of a thermal module with heat pipe in accordance with a third embodiment of the present invention. This embodiment is substantially similar to the aforesaid first embodiment with the exception that the accommodation groove  113  is curved, having two transverse retaining grooves  117  respectively disposed near the two distal ends  118  thereof; the heat pipe  120  is a curved pipe fitting the curved profile of the accommodation groove  113 . 
         [0044]    According to this third embodiment, the heat pipe  120  is a curved pipe. This embodiment achieves the various effects of the aforesaid first embodiment. Further, the heat pipe  120  is a rectangular pipe. The accommodation groove  113  has a rectangular cross section fitting the rectangular cross section of the heat pipe  120 . This design relatively increases the heat absorbing area of the heat pipe  120 . According to this third embodiment and the aforesaid first embodiment, the shape of the accommodation groove  113  is determined subject to the shape of the heat pipe  120 . 
         [0045]      FIG. 5  is an exploded view of a thermal module with heat pipe in accordance with a fourth embodiment of the present invention. Please refer also to  FIG. 2 , the thermal module with heat pipe in accordance with this fourth embodiment is comprised of a heat-dissipation plate  21 , a plurality of heat pipes  22 , and a bonding glue  23 . The heat-dissipation plate  21  has a top surface  214 , a bottom surface  215 , a plurality of accommodation grooves  211  formed in the top surface  214 , and a plurality of transverse retaining grooves  212  respectively formed in the accommodation grooves  211  near the two distal ends of the associating accommodation grooves  211 . The heat pipes  22  are respectively accommodated to the accommodation grooves  211  of the heat-dissipation plate  21  by the bonding glue  23 . Further, the bottom surface  215  of the heat-dissipation plate  21  is attached to a heat generating electronic device  25 , for example, a CPU. 
         [0046]    Further, the shape of the accommodating grooves  211  fits the shape of the heat pipes  22 . According to this embodiment, the accommodation grooves  211  are straight grooves; the heat pipes  22  are straight pipes respectively fitted into the accommodation grooves  211 . 
         [0047]    Similar to the aforesaid first embodiment, the retaining grooves  212  prevent overflow of the bonding glue  23 , i.e., this embodiment facilitates the quality control and saves the cost, and the finished thermal module with heat pipe according to this embodiment has a nice outer appearance. 
         [0048]      FIG. 6  is a perspective view of a thermal module with heat pipe in accordance with a fifth embodiment of the present invention. This embodiment is substantially similar to the aforesaid fourth embodiment with the exception of the use of a top cover  24  (as well as second embodiment), which has a bottom surface  241  abutted against the top surface  214  of the heat-dissipation plate  21 , and a plurality of accommodation grooves  242  formed in the bottom surface  241  to accommodate the heat pipes  22 . 
         [0049]      FIG. 7  is an exploded view of a thermal module with heat pipe in accordance with a sixth embodiment of the present invention. This embodiment is substantially similar to the aforesaid fourth embodiment with the exception that the transversely extending retaining grooves  312  in the accommodation grooves  311  at the same end are connected to one another in series. This embodiment achieves the same various effects of the aforesaid various embodiments. 
         [0050]      FIG. 8  is an exploded view of a thermal module with heat pipe in accordance with a seventh embodiment of the present invention. This embodiment is substantially similar to the aforesaid fourth embodiment with the exception that the accommodation grooves  213  of the thermal module with heat pipe of this seventh embodiment are curved grooves and the retaining grooves  216  in the accommodation grooves  213  are spaced apart. Further, the heat pipes  220  are curved pipes fitting the curved accommodation grooves  213 . Therefore, this seventh embodiment achieves the same various effects of the aforesaid various different embodiments of the present invention. 
         [0051]      FIG. 9  is an exploded view of a thermal module with heat pipe in accordance with an eighth embodiment of the present invention. This embodiment is substantially similar to the aforesaid seventh embodiment with the exception that the retaining grooves  316  in the accommodation grooves  313  at the same side are connected to one another in series. 
         [0052]      FIG. 10  is an exploded view of a thermal module with heat pipe in accordance with a ninth embodiment of the present invention. According to this embodiment, the accommodation grooves  41  and  42  of the heat-dissipation plate  45  have different shapes corresponding to different heat pipes  43  and  44 , i.e., the heat-dissipation plate  45  has a curved accommodation groove  41  and a straight accommodation groove  42 , and the heat pipes  43  and  44  have different shapes that fit the curved accommodation groove  41  and the straight accommodation groove  42  respectively. Further, each accommodation groove  41  or  42  has two transversely extending retaining grooves  411  or  421  disposed near the two distal ends to prevent overflow of the bonding glue (not shown). This embodiment achieves the same various effects of the aforesaid various different embodiments of the present invention. 
         [0053]    As stated in the aforesaid various embodiments of the present invention, the retaining grooves are designed subject to actual requirements, for example, the number of the retaining grooves can be two or more than two that are formed in the accommodation groove or at least one of the accommodation grooves near the two distal ends. The retaining grooves in the accommodation grooves at the same side can be designed kept apart, or connected to one another in series. Alternatively, the number of the retaining grooves can be four, and the four retaining grooves are respectively disposed in two accommodation grooves near two distal ends. In general, the number and arrangement of the retaining grooves may be variously embodied to fit the accommodation grooves subject to different requirements. 
         [0054]    Further, the retaining grooves can be made having any of a variety of cross-sectional shapes. For example, the retaining grooves can be made having a rectangular, triangular, semicircular, or trapezoidal shape. 
         [0055]    Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.