BACKGROUND OF THE INVENTION  
       [0001]     1. Field of Invention  
         [0002]     The present invention relates to an electronic device. More particularly, the present invention relates to an electronic device with heat dissipation module.  
         [0003]     2. Description of Related Art  
         [0004]     Recently, along with the rapid advance of technology, the calculation speed of electronic devices inside host computers is increased continuously. The heat-generating efficiency of electronic devices also increases constantly along with the advance of calculation speed of electronic devices. To prevent overheating the electronic devices inside the host computers that may lead to a temporary or permanent failure of the electronic devices, the electronic devices are required having efficient heat dissipation so as to function properly.  
         [0005]      FIG. 1  is a stereogram illustrating a conventional electronic device. Referring to  FIG. 1 , the conventional electronic device  100  has a printed circuit board  110 , a heat dissipation module  120 , a heat-generating element  130 , a locking backboard  140 , a plurality of elastic elements  150  and a plurality of screws  160 . Wherein, the heat-generating element  130  is disposed on the printed circuit board  110 , and the heat dissipation module  120  is fixed on a contact surface  130   a  of the heat-generating element  130 . In addition, the locking backboard  140  which has a plurality of bolt posts  142  is disposed under the printed circuit board  110 . In other words, the bolt posts  142  protrude from the printed circuit board  110 . Moreover, the elastic element  150  has a plurality of through holes  152  and is riveted at one side of the heat dissipation module  120 .  
         [0006]     In addition, the heat dissipation module  120  can be fixed on the heat-generating element  130  successfully by passing at least four screws  160  through the through holes  152  on the elastic elements  150  and screwing them down to the bolt posts  142  respectively, then the elastic elements  150  will give the heat dissipation module  120  a downward pressure so that the heat dissipation module  120  may make close contact with the heat-generating element  130 .  
         [0007]     When the electronic device  100  is in operation, the heat-generating element  130  is in the status of high temperature, by making contact with the heat dissipation module  120 , the heat-generating element  130  may transfer its heat to the heat dissipation module  120  through heat conduction, and then the temperature of the heat-generating element  130  may be reduced through heat convection between the heat dissipation module  120  and the air around it. Thereby, the electronic device  100  will not be overheated.  
         [0008]     However, to secure the heat dissipation module on the heat-generating element, a plurality of screws has to be fixed on the corresponding bolt posts so that the elastic element may supply a downward pressure to the heat dissipation module as described above. Thus, a lot of time will be spent over the aforesaid fixing procedure. Hence, how to reduce the fixing time for securing the heat dissipation module on the heat-generating element is a very important task. Moreover, if the degree of tightness between each screw and its corresponding bolt post is different, the downward pressure supplied to the heat dissipation module by the elastic elements disposed at each side of the heat dissipation module will be different and this will cause uneven pressure on the heat dissipation module fixed on the heat-generating element. As a result, not only the heat dissipation capability of the heat dissipation module on the heat-generating element but also the performance of the electronic device will be affected, so that how to make the heat dissipation module receives even pressure when it is fixed on the heat-generating element is another important issue.  
       SUMMARY OF THE INVENTION  
       [0009]     Accordingly, the present invention is directed to provide an electronic device; within this electronic device the heat dissipation module can be secured on the heat-generating element through simple operation to reduce assembly time.  
         [0010]     To achieve the aforesaid feature, the present invention provides an electronic device with sliding type heatsink, including a printed circuit board, a heat dissipation module and at least a guide post. Wherein, a heat-generating element is disposed on the printed circuit board, and the heat dissipation module is disposed on the heat-generating element. The heat dissipation module is disposed with at least an elastic element which has an assembly hole, and the assembly hole has a guide part and a first fixing part. In addition, the guide post protrudes from the printed circuit board and passes through the assembly hole, and there is a groove at one side of the guide post. Wherein, the guide post has a first external diameter, and a corresponding second external diameter at the groove, the second external diameter is smaller than the first external diameter. When the heat dissipation module moves a suited distance, the groove will slide into the first fixing part from the guide part so that the guide post fastens on the first fixing part. Wherein, a first internal diameter of the guide part is greater than a second internal diameter of the first fixing part, and the second internal diameter is substantially equal to the second external diameter.  
         [0011]     According to an embodiment of the present invention, the assembly hole is, for example, a gourd-shaped hole. Wherein, the guide part is a fist hole, the first fixing part is a second hole, and the first hole is joined to the second hole to form a gourd-shaped hole.  
         [0012]     According to an embodiment of the present invention, the electronic device, for example, further includes a guide post bracket, and the guide post is fixed on the guide post bracket. Wherein, the guide post bracket is adjacent to a surface of the printed circuit board, i.e. the guide post passes through the printed circuit board.  
         [0013]     According to an embodiment of the present invention, the electronic device further includes, for example, at least a screw and a bolt post. The screw is used for fastening the heat dissipation module to the bolt post. Wherein, the bolt post is, for example, fixed on the guide post bracket and is protruding from the printed circuit board.  
         [0014]     According to an embodiment of the present invention, the elastic element is, for example, an elastic metal.  
         [0015]     According to an embodiment of the present invention, the heat dissipation module includes, for example, a base, a second fixing part and at least a heatsink fin. Wherein, the heatsink fin is located at the first side of the base, and a second side of the base is opposite the first side and meets the heat-generating element. In addition, the second fixing part is at one side of the base, and the elastic element is fixed to the second fixing part.  
         [0016]     According to an embodiment of the present invention, the assembly hole is, for example, located at a curving part of the elastic element. The guide part of the assembly hole is closer to the printed circuit board than the first fixing part of the assembly hole. When the groove slides into the first fixing part from the guide part, the guide post will force the elastic element to bend toward the printed circuit board to fix the heat dissipation module.  
         [0017]     As afore-mentioned, in an electronic device of the present invention, the heat dissipation module only needs to slide a suited distance, so that with the interaction between the elastic element allocated on the heat dissipation module and the guide post allocated on the guide post bracket, the elastic element on the heat dissipation module may supply a downward pressure on the heat dissipation module. Accordingly, the heat dissipation module and the heat-generating element may maintain a status of close contact. In addition, the heat dissipation module may be fastened to a bolt post with only one screw; accordingly, the relative location between the elastic element and the guide post may be fixed so that the elastic element may maintain a status of pressing downward constantly; the heatsink may also be in close contact with the heat-generating element. Therefore, it is possible to secure the heat dissipation module to the heat-generating element with a simple operation to reduce assembly time. Moreover, the amount of screws used can be decreased according to the present invention.  
         [0018]     In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, a preferred embodiment accompanied with figures is described in detail below.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
         [0020]      FIG. 1  is a stereogram illustrating a conventional electronic device.  
         [0021]      FIG. 2  is a comprehensive diagram illustrating an electronic device according to exemplary embodiments of the present invention.  
         [0022]      FIG. 3  is a stereogram of the electronic device in  FIG. 2 .  
         [0023]      FIG. 4  is a stereogram of the elastic element in  FIG. 3 .  
         [0024]      FIG. 5  is a stereogram of the heat dissipation module in  FIG. 3 .  
         [0025]      FIG. 6   a  is a top view of the heat dissipation module in  FIG. 3  when it is not fixed with the heat-generating element closely.  
         [0026]      FIG. 6   b  is an enlarged profile view of the heat dissipation module in  FIG. 6   a  cut along line A-A′.  
         [0027]      FIG. 7   a  is a top view of the heat dissipation module in  FIG. 3  after it is fixed with the heat-generating element closely.  
         [0028]      FIG. 7   b  is an enlarged profile view of the heat dissipation module in  FIG. 7   a cut along line A-A′. 
     
    
     DESCRIPTION OF EMBODIMENTS  
       [0029]      FIG. 2  is a comprehensive diagram illustrating an electronic device according to the exemplary embodiments of the present invention and  FIG. 3  is a stereogram of the electronic device in  FIG. 2 . Referring to both  FIG. 2  and  FIG. 3 , in the present embodiment, the electronic device  200  includes a printed circuit board  210 , a heat dissipation module  220  and one or multiple guide posts  230 . Wherein, a heat-generating element  212  is disposed on the printed circuit board  210 , the heat-generating element  212  is, for example, a Central Processing Unit (CPU) of a computer or a North Bridge chip and so on. In addition, the heat dissipation module  220  is located on the heat-generating element  212  and is in contact with an contact surface  212   a  of the heat-generating element  212 . The heat dissipation module  220  is used for dissipating the heat inside the heat-generating element  212  so as to reduce the temperature of the heat-generating element  212 . As a result, the heat-generating element  212  is prevented from being temporarily or permanently failed because of the overheating which may further affect the operation of the electronic device  200 .  
         [0030]     The electronic device  200  further includes, for example, a guide post bracket  240  used for fixing itself with the heat dissipation module and further allowing the heat dissipation module  220  to make contact with the heat-generating element  212  closely. With the fixture between the heat dissipation module  220  and the guide post bracket  240 , it will avoid the direct fixture between the heat dissipation module  220  and the printed circuit board  210  which may cause the printed circuit board  210  to be destroyed or distorted. Wherein, the guide post bracket  240  is adjacent to a surface of the printed circuit board  210  (the bottom side of the printed circuit board  210 ). In addition, the guide post  230  is fixed on the guide post bracket  240 , that is, the guide post  230  passes through the printed circuit board  210 . Certainly, the guide post  230  may also be fastened directly on the printed circuit board  210  or may be fixed with other supporting structures.  
         [0031]     In addition, the heat dissipation module  220  is in close contact with the heat-generating element  212  through the aforementioned guide post  230  and one or multiple elastic elements  250  allocated on the heat dissipation module  220 . The elastic elements  250  are, for example, elastic metal. Wherein, the location where the elastic element  250  is located on the heat dissipation module  220  is opposite to the guide post  230  on the guide post bracket  240 ; with the interaction between the guide post  230  and the elastic element  250 , the elastic element  250  may supply a downward pressure on the heat dissipation module  220  to keep the heat dissipation module  220  and the heat-generating element  212  in close contact.  
         [0032]      FIG. 4  is a stereogram of the elastic element in  FIG. 3 . Referring to  FIG. 4 , the elastic element  250  has an assembly hole  252  which has a guide part  254  and a first fixing part  256 . Wherein, the guide part  254  has a first internal diameter (not shown), and the first fixing part  256  has a second internal diameter (not shown), the first internal diameter of the guide part  254  is greater than the second internal diameter of the first fixing part  256 . Moreover, there may be formed a curving part  250   a  on the elastic element  250  where the smallest aperture part  252   a  of the assembly hole  252  is located to place two bigger apertures of the assembly hole at different planes, for example, the bigger aperture of the guide part  254  is at the first platform P 1  and the bigger aperture of the first fixing part  256  is at the second platform P 2 , wherein the guide part  254  is closer to the printed circuit board  210  than the first fixing part  256 .  
         [0033]     As described, the guide part  254  is, for example, a first hole, and the first fixing part  256  is, for example, a second hole; the first hole is joined with the second hole to form a gourd-shaped hole. On the other hand, the guide post  230  protrudes from the printed circuit board  210  and is located in the assembly hole  252 . Wherein, there is a groove  232  at one side of the guide post  230  and which is formed by machining the side of the guide post  230  by, for example, cutting a snick of suited depth at the side of the guide post  230 , and the groove  232  is joined with the first fixing part  256 . In addition, the guide post  230  has a first external diameter (not shown), and the guide post  230  has a second external diameter (not shown) at the groove  232 , the second external diameter is smaller than the first external diameter. The second external diameter is, for example, the smaller external diameter generated by machining the guide post  230 , wherein the second external diameter is substantially equal to the second internal diameter of the first fixing part  256 .  
         [0034]     Next, the allocation pattern of the elastic element  250  on the heat dissipation module  220  and the interaction between the guide post  230  and the elastic element  250  will be described in detail.  
         [0035]      FIG. 5  is a stereogram of the heat dissipation module in  FIG. 3 . Referring to both  FIGS. 3 and 5 , the heat dissipation module  220  includes, for example, a base  222 , a second fixing part  224  and one or multiple heatsink fins  226 . Wherein, a side of the base  222  has a plurality of bulgy parts  228 , the second fixing part  224  is at the bulgy part  228 , and the elastic element  250  is assembled between two adjacent bulgy parts  228 . The operation to dispose the elastic element  250  on the heat dissipation module  220  may be achieved by riveting the elastic element  250  to the second fixing part  224  on the bulgy part  228 . In addition, the heatsink fins  226  are located at a first side  222   a  of the base  222 , and a second side  222   b  of the base  222  is opposite the first side  222   a  and is in contact with the surface of the heat-generating element  212 , wherein the material of the base  222  and the heatsink fins  226  are a material with better heat conductibility, for example, copper or aluminum.  
         [0036]     In the embodiment of the present invention, the heat dissipation module  220  and the heat-generating element  212  may maintain a status of close contact through the interaction between the guide post  230  and the elastic element  250 . The interaction between the guide post  230  and the elastic element  250  will be further described here.  FIG. 6   a  is a top view of the heat dissipation module in  FIG. 3  when it is not in close contact with the heat-generating element.  FIG. 6   b  is an enlarged profile view of the heat dissipation module in  FIG. 6   a  cut along line A-A′. Referring to both  FIGS. 6   a  and  6   b , when the heat dissipation module  220  is not in close contact with the heat-generating element  212 , the guide post  230  is located in the guide part  254  of the assembly hole  252 . Wherein, the second external diameter of the guide post  230  is smaller than the first internal diameter of the guide part  254 , so that the guide post  230  and the guide part  254  are in a status of loose assembly. Thus, the guide post  230  may be fastened easily into the first fixing part  256  from the guide part  254  by supplying only a level power to the heat dissipation module  220 , the aforesaid process will be described in detail below.  
         [0037]     Refer to  FIG. 7   a  which is a top view of the heat dissipation module in  FIG. 3  after it is fixed with the heat-generating element closely. As illustrated in the figure, after a level power is supplied to the heat dissipation module  220  to move the heat dissipation module  220  a suited distance, the guide post  230  located in the assembly hole will be fastened into the first fixing part  256  from the guide part  254 . Here, the second external diameter of the guide post  230  is equal to the second internal diameter of the first fixing part  256 , thus the guide post  230  and the first fixing part  256  are in a status of tight assembly. Next, refer to  FIG. 7   b  which is an enlarged profile view of the heat dissipation module in  FIG. 7   a  cut along line A-A′. As illustrated in the figure, during the process of fastening the guide post  230  into the first fixing part  256  from the guide part  254 , since the guide part  254  and the first fixing part  256  are at the first platform P 1  and the second platform P 2  of the step changes respectively (as shown in  FIG. 4 ), and the guide part  254  is closer to the printed circuit board  210  than the first fixing part  256  (as shown in  FIG. 6   b ), when the groove  232  is sliding into the first fixing part  256  from the guide part  254 , the guide post  230  will force the elastic element  250  to bend towards the printed circuit board  210  and supply a downward pressure on the heat dissipation module  220 , so that the heat dissipation module  220  and the heat-generating element  212  may stay in close contact.  
         [0038]     After fastening the guide post  230  on the first fixing part  256 , to keep the guide post  230  fixed to the first fixing part  256 , one screw  260  may be used to fasten a side of the heat dissipation module  220  on a bolt post  270  on the guide post bracket  240 , wherein the bolt post  270  protrudes from the printed circuit board  210 . Thereby the relative locations of the elastic element  250  and the guide post  230  are fixed, so that the elastic element  250  may keep pressing downwards, and the heatsink may also be able to maintain close contact with the heat-generating element.  
         [0039]     According to the present embodiment, only the heat dissipation module  220  receiving a downwards pressure from an elastic element  250  by the interaction between the elastic element  250  and a guide post  230  is described. In the present invention, a plurality of elastic elements  250  and corresponding guide posts  230  may be used to supply the downward pressure to the heat dissipation module  220  to keep the heat dissipation module  220  and the heat-generating element  212  in contact with each other closely. The procedure of the interaction between a plurality of elastic elements  250  and corresponding guide posts  230  is identical to the description of the present embodiment and will not be described again.  
         [0040]     In overview, in an electronic device of the present invention, the heat dissipation module only needs to slide a suited distance to allow the elastic element on the heat dissipation module supplying a downward pressure to the heat dissipation module through the interaction between the elastic element disposed on the heat dissipation module and the guide post disposed on the guide post bracket, thus the heat dissipation module and the heat-generating element may stay in close contact. Moreover, the heat dissipation module may be fixed to a bolt post with only one screw, so that the relative positions between the elastic element and the guide post are fixed and which allows the elastic element to press downwards constantly and the heatsink to stay in close contact with the heat-generating element. Accordingly, the heat dissipation module may be secured on the heat-generating element with simple operation to reduce assembly time. In other words, the quantity of screws used and the time spent on positioning the screws in the present invention are saved.  
         [0041]     In addition, in the conventional procedure to fix a plurality of screws to the bolt posts to allow the heat dissipation module to be fixed to the heat-generating element with elastic elements, if the degree of tightness of between each screw and its corresponding bolt post is different, the heat dissipation module fixed on the heat-generating element will be under uneven pressure and this may further affect the heat dissipation capability of the heat dissipation module on the heat-generating element and the performance of the electronic device. However, in the electronic device of the present invention, the heat dissipation module is fixed on the heat-generating element through the interaction between the elastic element and the guide post, thus the heat dissipation module fixed on the heat-generating element in the present invention will receive even pressure and which allows the heat dissipation module has better heat dissipation performance on the heat-generating element and further enhance the overall quality of the electronic device.  
         [0042]     While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
An electronic device with sliding type heatsink including a printed circuit board, a heat dissipation module and at least a guide post is provided. Wherein, a heat-generating element is disposed on the printed circuit board, and the heat dissipation module is disposed on the heat-generating element. The heat dissipation module includes at least an elastic element which has an assembly hole. The assembly hole has a guide part and a first fixing part. Besides, the guide post protrudes from the printed circuit board and is located in the assembly hole. A side of the guide post has a groove. When the heat dissipation module moves a suited distance, the groove slides into the first fixing part from the guide part that makes the guide post fix with the first fixing part. Thus, the heat dissipation module can tightly fix on the heat-generating element.