Patent Publication Number: US-2013235529-A1

Title: Heat conducting device and electronic device applying the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application No. PCT/CN2011/074077, filed on May 16, 2011, which claims priority to Chinese Patent Application No. 201010539924.0, filed on Nov. 11, 2010, both of which are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a heat conducting device, and more specifically, to a heat conducting device applicable in electronic devices. 
     DESCRIPTION OF THE RELATED ART 
     In current electronic devices, with the continuous abundant of functions, corresponding power consumption is constantly increasing, as a result, heat dispersion of electronic devices has become an important issue restricting the development of electronic devices. In order to enable heat produced in an electronic product to transfer to a heat dispersion device in time, a heat conducting medium is generally provided between the heat source of the electronic product and the heat dispersion device, so that heat produced from the heat source of the electronic product may be conducted to the heat dispersion device. 
     In the implementation of this invention, the inventors have recognized at least the following problems in the prior art. 
     Due to manufacture errors, the distance between the heat source of an electronic product and an heat dispersion device is not constant, which may vary in a certain range. However, most existing heat conducting mediums are unable to self-adapt to an appropriate thickness to fit variations in distance between the heat source and the heat dispersion device, leading to higher thermal resistance between the heat source and the heat dispersion device, preventing rapid heat conduction consequently. 
     SUMMARY OF THE INVENTION 
     A heat conducting device with high thermal conductivity and reliability and an electronic device applying the same heat conducting device are provided in embodiments of this invention. 
     A heat conducting device, comprising a first heat conducting board and a heat conducting structure is provided. The first heat conducting board comprises an upper heat conducting arm provided on one surface of the first heat conducting board. The heat conducting structure slidably abuts on the upper heat conducting arm of the first heat conducting board to form a contact surface through which heat transfer is realized. The heat conducting structure comprises a heat conducting surface, which is used to keep the relative position of the first heat conducting board and the heat conducting surface. The distance between the first heat conducting board and the heat conducting surface of the heat conducting structure may be varied by means of relative sliding between the upper heat conducting arm and the heat conducting structure, at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm of the first heat conducting board and the heat conducting structure. 
     An electronic device applying the above heat conducting device is provided. The electronic device comprises a circuit board, multiple chips provided on the circuit board, a heat dispersing shield provided on the circuit board for accommodating the chips, a heat dispersion device provided on the heat dispersing shield, and multiple heat conducting devices. The multiple heat conducting devices are provided between the chips and the heat dispersing shield. First heat conducting boards of the heat conducting devices are closely adhered to the chips, the heat conducting structures of the heat conducting devices tightly abut on the heat dispersing shield through their heat conducting surfaces. 
     The heat conducting device and the electronic device applying the heat conducting device provided in embodiments of this invention may adjust its own thickness through sliding between an upper heat conducting arm and a lower heat conducting arm according to different use environments and manufacture errors to fit variations in distance between a heat source and a heat dispersing structure, so that effective heat conduction of electronic products can be guaranteed and heat dispersion effect can be improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a heat conducting device provided according to a first embodiment of this invention; 
         FIG. 2  is a side view of a heat conducting device provided according to a second embodiment of this invention; 
         FIG. 3  is a side view of a heat conducting device provided according to a third embodiment of this invention; 
         FIG. 4  is a side view of a heat conducting device provided according to a fourth embodiment of this invention; 
         FIG. 5  is a side view of a heat conducting device provided according to a fifth embodiment of this invention; 
         FIG. 6  is a perspective exploded view of a heat conducting device provided according to the fifth embodiment of this invention; 
         FIG. 7  is a side view of a heat conducting device provided according to a sixth embodiment of this invention; 
         FIG. 8  is a side view of a heat conducting device provided according to a seventh embodiment of this invention; 
         FIG. 9  is a side view of another heat conducting device provided according to the seventh embodiment of this invention; 
         FIG. 10  is a side view of a third heat conducting device provided according to the seventh embodiment of this invention; 
         FIG. 11  is a side view of a heat conducting device provided according to an eighth embodiment of this invention; 
         FIG. 12  is a side view of a heat conducting device provided according to a ninth embodiment of this invention; 
         FIG. 13  is a perspective schematic view of the heat conducting structure of the heat conducting device of  FIG. 12 ; 
         FIG. 14  is a side view of a heat conducting device provided according to a tenth embodiment of this invention; 
         FIG. 15  is a perspective schematic view of the heat conducting structure of the heat conducting device of  FIG. 14 ; 
         FIG. 16  is a side view of another heat conducting device provided according to the tenth embodiment of this invention; 
         FIG. 17  is a side view of another electronic device provided according to the eleventh embodiment of this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 ,  FIG. 1  is a side view of a heat conducting device  100  provided in a first embodiment of this invention. The heat conducting device  100  comprises a first heat conducting board  110  and a heat conducting structure  130 . The first heat conducting board  110  comprises at least one upper heat conducting arm  120  provided on a side surface of the first heat conducting board  110 . The heat conducting structure  130  slidably abuts on the upper heat conducting arm  120  of the first heat conducting board  110  to form a contact surface through which heat transfer is performed. The heat conducting structure  130  comprises a heat conducting surface  131  contacting with a heat source or a heat dispersion device, the heat conducting structure  130  is used to keep a relative position of the first heat conducting board  110  and the heat conducting surface  131 , and the distance between the first heat conducting board  110  and the heat conducting surface  131  of the heat conducting structure  130  may be varied by means of relative sliding between the upper heat conducting arm  120  and the heat conducting structure  130 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  120  of the first heat conducting board  110  and the heat conducting structure  130 . 
     The first heat conducting board  110  comprises a first surface  112  and a second surface  114  opposite to the first surface  112 . The upper heat conducting arm  120  is formed on the second surface  114  of the first heat conducting board  110 . It may be understood that the upper heat conducting arm  120  may be integrally formed with the first heat conducting board  110  or may be manufactured separately and then mounted to the first heat conducting board  110  through weld, screw connection, or other mechanical connection manner The first heat conducting board  110  and the upper heat conducting arm  120  are both formed by a metal with good thermal conductivity such as copper, aluminum, or a non-metal solid material such as graphite, boron nitride, and aluminum nitride, etc. 
     Each of the upper heat conducting arms  120  comprises an end surface  122  and a side surface  124  perpendicularly surrounding the periphery of the end surface  122 . Because the end surface  122  is perpendicular to the side surface  124 , the shape of the end surface  122  may reflect the shape of the cross section of the upper heat conducting arm  120 , the end surface  122  of the upper heat conducting arm  120  may be arranged to any shape as demand, for example, a regular polygon such as an equiangular triangle, a square, a rectangle, or an irregular polygon or a circle, an ellipse, etc. In this embodiment, the side surface  124  of the upper heat conducting arm  120  and the heat conducting structure  130  abut with each other. 
     In this embodiment, the heat conducting structure  130  comprises a second heat conducting board  132  and multiple groups of lower heat conducting arms  134  formed on the second heat conducting board  132  and mutually abutted with the upper heat conducting arms  120 . The second heat conducting board  132  comprises an upper surface  132   a  and a lower surface  132   b  opposite to the upper surface  132   a.  In this embodiment, the heat conducting surface  131  and the lower surface  132   b  of the second heat conducting board  132  are the same surface. The lower heat conducting arms  134  are provided on the upper surface  132   a  of the second heat conducting board  132  and form an angle with the upper surface  132   a,  wherein the angle has an optimal value of  90  degrees. Each group of the lower heat conducting arms  134  comprises two heat conducting reeds  134   a,    134   b  having the same structure and symmetrically provided on the upper surface  132   a  of the second heat conducting board  132 . For concision, the structure of heat conducting reeds  134   a,    134   b  will be described with the heat conducting reed  134   a  as an example. Each of the heat conducting reeds  134   a  comprises a support portion  134   c  and a resilient portion  134   d  formed at one end of the support portion  134   c.  The support portion  134   c  comprises a fixed end  134   e  and a free end  134   f  corresponding to the fixed end  134   e.  The support portion  134   c  is fixed on the upper surface  132   a  of the second heat conducting board  132  via fixed end  134   e  of the support portion  134   c.  The resilient portion  134   d  is coupled on the free end  134   f  of the support portion  134   c  and forms an angle with the support portion  134   c,  preferably, a sharp angle. The resilient portions  134   d  of the two heat conducting reeds  134   a,    134   b  of each group of lower heat conducting arms  134  face with each other and are spaced with a distance to form a receiving space  136  for receiving an upper heat conducting arm  120 . In this embodiment, the lower heat conducting arms  134  are formed by beryllium bronze, spring steal, etc. It can be understood that the lower heat conducting arm  134  and the upper heat conducting arms  120  are exchangeable in position, that is, the lower heat conducting arms  134  can be provided on the second surface  114  of the first heat conducting board  110  and the upper heat conducting arms  120  can be correspondingly provided on the upper surface  132   a  of the second heat conducting board  132 . 
     In use, an upper heat conducting arm  120  on the first heat conducting board  110  corresponds to a corresponding group of heat conducting reeds  134   a,    134   b  on the heat conducting structure  130 , and the end surface  122  of the upper heat conducting arm  120  is abutted against the resilient portions  134   d  of the heat conducting reeds  134   a,    134   b.  Then, a prepressure is applied on the first heat conducting board  110  to insert the upper heat conducting arm  120  into the receiving space  136  of a corresponding lower heat conducting arm  134 . Under the pressure, the resilient portion  134   d  of each of the heat conducting reeds  134   a,    134   b  resilientally bends in the direction of the support portion  134   c,  and the bent resilient portion  134   d  closely abut against the side surface  124  of the upper heat conducting arm  120  to keep effective heat transfer through a contact surface between the heat conducting reeds  134   a,    134   b  and the upper heat conducting arm  120 , at the same time, to keep a relative position between the heat conducting surface  131  of the heat conducting structure  130  and the first heat conducting board  110 . When the distance between the heat conducting surface  131  of the heat conducting structure  130  and the first heat conducting board  110  is required to be adjusted, it is only needed to apply a pressure on the first heat conducting board  110  or release the pressure applied on the first heat conducting board  110  to realize the adjustment of the distance between the heat conducting surface  131  of the heat conducting structure  130  and the first heat conducting board  110  through relative sliding between the heat conducting structure  130  and the first heat conducting board  110 . When such a heat conducting device  100  is used in an electronic device, accumulative tolerances produced in the manufacture of the electronic device can be compensated to achieve the purpose of facilitating assembly and manufacture, at the same time, the effectiveness of the heat conducting path can be guaranteed, and heat dispersion effect can be improved during the use of the electronic product. 
     Referring to  FIG. 2 ,  FIG. 2  is a side view of a heat conducting device  200  provided according to a second embodiment of this invention. The structure of the heat conducting device  200  is similar to that of the heat conducting device  100  of the first embodiment, comprising a first heat conducting board  210  and a heat conducting structure  230 , wherein the first heat conducting board  210  comprises at least one upper heat conducting arm  220  provided on one side surface of the first heat conducting board  210 . The heat conducting structure  230  is directly aligned to the upper heat conducting arm  220  of the first heat conducting board  210  and slidably abuts against the upper heat conducting arm  220  to perform heat transfer through the contact surface between the heat conducting structure  230  and the upper heat conducting arm  220 . The heat conducting structure  230  comprises a heat conducting surface  231 , the heat conducting structure  230  is used to keep the relative position between the first heat conducting board  210  and the heat conducting surface  231 , and the distance between the first heat conducting board  210  and the heat conducting surface  231  of the heat conducting structure  230  can be varied by means of relative sliding between the upper heat conducting arm  220  and the heat conducting structure  230 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  220  of the first heat conducting board  210  and the heat conducting structure  230 . The heat conducting device  200  provided in the second embodiment differs from the heat conducting device  100  provided in the first embodiment in the following aspects. 
     In this embodiment, each upper heat conducting arm  220  comprises two structure symmetric resilient sheets  222 , wherein each resilient sheet  222  comprises a connecting segment  222   a  and an abutting segment  222   b  connected to the connecting segment  222   a.  The connecting segment  222   a  is connected to a second surface  114  of the first heat conducting board  210  at one end and forms an angle with the second surface  114 , optimally an angle of 90 degrees. The abutting segment  222   b  is connected to the end of the connecting segment  222   a  apart from the first heat conducting board  210 , and forms an angle with the connecting segment  222   a,  preferably, a sharp angle. The two resilient sheets  222  of each upper heat conducting arm  220  are symmetrically arranged on the second surface  214  of the first heat conducting board  210 , and the abutting segments  222   b  of the two resilient sheets  222  are located on departure sides of the two connecting segment  222   a  of the two resilient sheets  222  respectively, so that a taper with a cross section gradually reduced along the direction of from a position close to the first heat conducting board  210  toward a position apart from the first heat conducting board  210  is formed. 
     In this embodiment, the heat conducting structure  230  comprises a second heat conducting board  232  and multiple groups of lower heat conducting arms  234  formed on the second heat conducting board  232  and mutually abutted with the upper heat conducting arms  220 . The second heat conducting board  232  comprises an upper surface  232   a  and a lower surface  232   b  opposite to the upper surface  232   a.  In this embodiment, the heat conducting surface  231  and the lower surface  232   b  of the second heat conducting board  232  are the same surface. The lower heat conducting arms  234  are provided on the upper surface  232   a  of the second heat conducting board  232  and form an angle with the upper surface  232   a,  optimally an angle of 90 degrees. Each group of the lower heat conducting arms  234  comprises two heat conducting reeds  234   a,    234   b  having the same structure and symmetrically arranged on the upper surface  232   a  of the second heat conducting board  232 . In this embodiment, the heat conducting reeds  234   a,    234   b  are leaf springs perpendicularly provided on the second heat conducting board  232  and spaced with a distance to form a receiving space  236  for receiving an upper heat conducting arm  220 . In this embodiment, each of the upper heat conducting arms  220  and lower heat conducting arms  234  is formed by a resilient material such as beryllium bronze, spring steal, etc. It can be understood that the lower heat conducting arms  234  and the upper heat conducting arms  220  are exchangeable in position, that is, the lower heat conducting arms  234  can be provided on the second surface  114  of the first heat conducting board  210  and the upper heat conducting arms  220  can be correspondingly provided on the upper surface  232   a  of the second heat conducting board  232 . 
     In use, each upper heat conducting arm  220  on the first heat conducting board  210  corresponds to a corresponding group of heat conducting reeds  234   a,    234   b  on the heat conducting structure  230  to abut the abutting segments  222   b  of the upper heat conducting arm  220  against the heat conducting reeds  234   a,    234   b.  Then, a prepressure is applied on the first heat conducting board  210  to insert the upper heat conducting arm  220  into the receiving space  236  of the corresponding lower heat conducting arm  234 . The resilient sheets  222  of the upper heat conducting arm  220  and the heat conducting reeds  234   a,    234   b  mutually abutted with the resilient sheets  222  produce a resilient deformation under the prepressure, a resilient restoring force produced by the resilient deformation make the abutting segments  222   b  of the upper heat conducting arm  220  closely abutted against the heat conducting reeds  234   a,    234   b,  so as to keep effective heat transfer through a contact surface between the heat conducting reeds  234   a,    234   b  and the resilient sheets  222 , at the same time, to keep the relative position between the heat conducting surface  231  of the heat conducting structure  230  and the first heat conducting board  210 . When the distance between the heat conducting surface  231  of the heat conducting structure  230  and the first heat conducting board  210  is required to be adjusted, it is only needed to apply a pressure on the first heat conducting board  210  or release the pressure applied on the first heat conducting board  210  to realize the adjustment of the distance between the heat conducting surface  231  of the heat conducting structure  230  and the first heat conducting board  210  through relative sliding between the heat conducting structure  230  and the first heat conducting board  210 . When such a heat conducting device  200  is used in an electronic device, accumulative tolerances produced in the manufacture of the electronic device can be compensated. Furthermore, position adjustment and heat transfer functions are realized through employing correspondingly provided resilient sheets  222  and heat conducting reeds  234   a,    234   b,  making the whole heat conducting device  200  lightened and simplified in structure. 
     Referring to  FIG. 3 ,  FIG. 3  is a side view of a heat conducting device  300  provided according to a third embodiment of this invention. The structure of the heat conducting device  300  is similar to that of the heat conducting device  100  of the first embodiment, comprising a first heat conducting board  310  and a heat conducting structure  330 , wherein the first heat conducting board  310  comprises at least one upper heat conducting arm  320  provided on a side surface of the first heat conducting board  310 . The heat conducting structure  330  is directly aligned to the upper heat conducting arm  320  of the first heat conducting board  310  and slidably abuts against the upper heat conducting arm  320  to perform heat transfer through the contact surface between the heat conducting structure  330  and the upper heat conducting arm  320 . The heat conducting structure  330  comprises a heat conducting surface  331  and is used to keep a relative position between the first heat conducting board  310  and the heat conducting surface  331 . The distance between the first heat conducting board  310  and the heat conducting surface  331  of the heat conducting structure  330  can be varied by means of relative sliding between the upper heat conducting arm  320  and the heat conducting structure  330 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  320  of the first heat conducting board  310  and the heat conducting structure  330 . The heat conducting device  300  provided in the third embodiment differs from the heat conducting device  100  provided in the first embodiment in the following aspects. 
     In this embodiment, multiple heat dispersing fins are constructed, which are regularly arranged on a first surface  312  of the first heat conducting board  310  and are used to rapidly disperse heat of the first heat conducting board  310  to the surrounding medium. 
     In this embodiment, a taper side  326  is formed between the end surface  322  and side surface  324  of each upper heat conducting arm  320 , which is connected between the side surface  324  and the end surface  322  with a connection angle, preferably a blunt angle. 
     In this embodiment, the heat conducting structure  330  comprises at least one mutually separated boom-type lower heat conducting arm  334 . The multiple lower heat conducting arms  334  have the same structure, each of which comprises a locating segment  334   a,  two resilient segments  334   b  connected to the opposite sides of the locating segment  334   a  respectively, and two resilient boom segments  334   c  connected to corresponding ends of the resilient segments  334   b.  The bottom of the locating segment  334   a  forms the heat conducting surface  331 . The two resilient segments  334   b  are connected to the opposite sides of the locating segment  334   a  with a certain angle. In order to make the resilient segments  334   b  resilient enough, the middle portions of the two resilient segments  334   b  are folded in opposite directions to form energy storage portions  334   d.  The two resilient boom segments  334   c  are connected to one the ends of the resilient segments  334   b  apart from the locating segment  334   a  by means of substantially parallel to the locating segment  334   a,  and are opposite to each other. It may be understood that the two resilient boom segments  334   c  may have their corresponding ends connected to form an integral structure which is connected to the resilient segments  334   b  at two ends. 
     In use, each upper heat conducting arm  320  on the first heat conducting board  310  corresponds to two resilient boom segments  334   c  of the heat conducting structure  330 , and the end surface  322  of the each upper heat conducting arm  320  is abutted against the resilient boom segments  334   c.  Then, a prepressure is applied on the first heat conducting board  310  to insert the upper heat conducting arm  320  between the two resilient segments  334   b  of the corresponding boom-type lower heat conducting arm  334 . The resilient boom segments  334   c  of the boom-type lower heat conducting arm  334  produce a resilient deformation toward the locating segment  334   a  under the prepressure. At that point, the taper side  326  formed on the upper heat conducting arm  320  is closely abutted against the folded resilient boom segments  334   c,  so that the upper heat conducting arm  320  sufficiently contacts the heat conducting structure  330  to guarantee effective heat transfer through the contact surface between the upper heat conducting arm  320  and the heat conducting structure  330 , at the same time, to keep a relative position between the heat conducting surface  331  of the heat conducting structure  330  and the first heat conducting board  310 . It is only needed to apply a pressure on the first heat conducting board  310  or release the pressure applied on the first heat conducting board  310  to realize the adjustment of the distance between the heat conducting surface  331  of the heat conducting structure  330  and the first heat conducting board  310  through relative sliding between the heat conducting structure  330  and the first heat conducting board  310 . When such a heat conducting device  300  is used in an electronic device, accumulative tolerances produced in the manufacture of the electronic device can be compensated. Furthermore, the multiple mutually separated boom-type lower heat conducting arm  334  on the heat conducting structure  330  have their own locating segments  334   a,  so that such a heat conducting structure  330  can be applied in an electronic device having multiple separated heat sources simultaneously to simplify the heat dispersing structure and reduce manufacture cost. 
     Referring to  FIG. 4 ,  FIG. 4  is a side view of a heat conducting device  400  provided according to a fourth embodiment of this invention. The structure of the heat conducting device  400  is similar to that of the heat conducting device  300  of the third embodiment, comprising a first heat conducting board  410  and a heat conducting structure  430 , wherein the first heat conducting board  410  comprises two upper heat conducting arms  420  spaced at a distance and provided on a side surface of the first heat conducting board  410 . The heat conducting structure  430  is directly aligned to the upper heat conducting arms  420  of the first heat conducting board  410  and slidably abuts against the upper heat conducting arm  420  to perform heat transfer through the contact surface between the heat conducting structure  430  and the upper heat conducting arms  420 . The heat conducting structure  430  comprises a heat conducting surface  431  and is used to keep a relative position between the first heat conducting board  410  and the heat conducting surface  431 . The distance between the first heat conducting board  410  and the heat conducting surface  431  of the heat conducting structure  430  can be varied by means of relative sliding between the upper heat conducting arms  420  and the heat conducting structure  430 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arms  420  of the first heat conducting board  410  and the heat conducting structure  430 . The heat conducting device  400  provided in the fourth embodiment differs from the heat conducting device  300  provided in the third embodiment in the following aspects. 
     In this embodiment, the heat conducting structure  430  comprises multiple mutually separated boom-type lower heat conducting arms  434 . The multiple boom-type lower heat conducting arms  434  have the same structure, and correspond to spacing regions between the multiple upper heat conducting arms  420  of the first heat conducting board  410 . Each of the lower heat conducting arms  434  comprises a locating segment  434   a,  two resilient segments  434   b  connected to the opposite sides of the locating segment  434   a  respectively, and two resilient boom segments  434   c  connected to corresponding ends of the resilient segments  434   b.  The bottom of the locating segment  434   a  forms the heat conducting surface  431 . The two resilient segments  434   b  are connected to the opposite sides of the locating segment  434   a  with a certain angle. The two resilient boom segments  434   c  are connected to the ends of the resilient segments  434   b  apart from the locating segment  434   a  along departure directions and are folded toward the locating segment  434   a.    
     In use, each upper heat conducting arm  420  on the first heat conducting board  410  corresponds to adjacent resilient boom segments  434   c  of two adjacent boom-type lower heat conducting arms  434  of the heat conducting structure  430 , and the end surface  422  of the upper heat conducting arm  420  is abutted against the resilient boom segments  434   c.  Then, a prepressure is applied on the first heat conducting board  410  to insert the upper heat conducting arm  420  between the two adjacent boom-type lower heat conducting arms  434 . The resilient boom segments  434   c  of the adjacent boom-type lower heat conducting arm  434  produce a resilient deformation toward the locating segment  434   a  under the prepressure. At that point, a taper side  426  formed on the upper heat conducting arm  420  is closely abutted against the folded resilient boom segments  434   c  to cause sufficiently contact between the upper heat conducting arm  420  and the heat conducting structure  430 , so as to guarantee effective heat transfer through the contact surface between the upper heat conducting arm  420  and the heat conducting structure  430 , and keep a relative position between the heat conducting surface  431  of the heat conducting structure  430  and the first heat conducting board  410  at the same time. The adjustment manner of the heat conducting device  400  provided in this embodiment is as same as that of the heat conducting device  300  provided in the third embodiment, and have the same advantages as the heat conducting device  300 . 
     Referring to  FIG. 5 ,  FIG. 5  is a side view of a heat conducting device  500  provided according to a fifth embodiment of this invention. The heat conducting device  500  comprises a first heat conducting board  510  and a heat conducting structure  530 , wherein the first heat conducting board  510  comprises at least one upper heat conducting arm  520  provided on a side surface of the first heat conducting board  510 . The heat conducting structure  530  is directly aligned to the upper heat conducting arm  520  of the first heat conducting board  510  and slidably abuts against the upper heat conducting arm  520  to perform heat transfer through the contact surface between the heat conducting structure  530  and the upper heat conducting arms  520 . The heat conducting structure  530  comprises a heat conducting surface  531  and is used to keep a relative position between the first heat conducting board  510  and the heat conducting surface. The distance between the first heat conducting board  510  and the heat conducting surface  531  of the heat conducting structure  530  can be varied by means of relative sliding between the upper heat conducting arms  520  and the heat conducting structure  530 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arms  520  of the first heat conducting board  510  and the heat conducting structure  530 . 
     The first heat conducting board  510  comprises a first surface  512  and a second surface  514  opposite to the first surface  512 . Two first locating posts  516  are formed on the second surface  514  of the first heat conducting board  510 , in this embodiment, the locating posts  516  are formed on the second surface  514  at positions close to an edge of the second surface  514 , but not limited to the above positions, the locating posts  516  can be provided on the second surface  514  at any required positions capable of ensuring the normal use of the heat conducting device  500 . 
     This embodiment comprises multiple upper heat conducting arms  520  spaced at a certain distance and distributed on the first heat conducting board  510 . The multiple upper heat conducting arms  520  are multiple plate structures provided on the second surface  514  of the first heat conducting board  510  in parallel. It may be understood that the upper heat conducting arms  520  may be integrally formed with the first heat conducting board  510 , or may be separately manufactured and then mounted to the first heat conducting board  510  through weld, screw connection or adherence. The first heat conducting board  510  and the upper heat conducting arms  520  are formed by a metal with good thermal conductivity such as copper, aluminum, or a non-metal solid material such as graphite, boron nitride, and aluminum nitride, etc. 
     Referring to  FIG. 6  also,  FIG. 6  is a perspective exploded view of a heat conducting device  500  provided according to the fifth embodiment of this invention. Each of the upper heat conducting arms  520  comprises an end surface  522  and a side surface  524  perpendicularly surrounding the periphery of the end surface  522 . Because the end surface  522  is perpendicular to the side surface  524 , the shape of the end surface  522  may represent the shape of the cross section of the upper heat conducting arm  520 , the end surface  522  of the upper heat conducting arm  520  may be arranged to any shape as required, for example a regular polygon such as an equiangular triangle, a square, a rectangle, or an irregular polygon or a circle, an ellipse, etc. In this embodiment, the side surface  524  of the upper heat conducting arm  520  is abutted against the heat conducting structure  530 . In this embodiment, multiple first screw holes  526  and multiple first sliding holes  528  are provided on two outermost upper heat conducting arms  520  among the multiple upper heat conducting arms  520 , wherein the first screw holes  526  are provided on a same upper heat conducting arm  520  and the first sliding holes  528  are provided on the other upper heat conducting arm  520 . 
     In this embodiment, the heat conducting structure  530  comprises a second heat conducting board  532 , multiple lower heat conducting arms  534  formed on the second heat conducting board  532 , multiple resilient elements  536  and multiple locking elements  538 . 
     The second heat conducting board  532  comprises an upper surface  532   a  and a lower surface  532   b  opposite to the upper surface  532   a.  In this embodiment, the heat conducting surface  531  and the lower surface  532   b  of the second heat conducting board  532  are the same surface. Two second locating posts  532   c  are formed on the upper surface  532   a  of the second heat conducting board  532 , which are symmetrically distributed in space with the first locating posts  516  on the first heat conducting board  510 , that is, the orthogonal projections of the first locating posts  516  and the second locating posts  532   c  on a plane where the second surface  514  of the first heat conducting board  510  locates are symmetrically distributed with respect to the geometric center of the second surface  514 . The second heat conducting board  532  is square in shape, and two lips  532   d  are formed at diagonal positions of the second heat conducting board  532 , with two through holes  532   e  provided on the two lips  532   d  for securing the second heat conducting board  532  to an attachment, such as a heat source or a heat dispersing shield in an electronic device, by fasteners passing through the through holes  532   e.  It may be understood that the lips  532   d  can be arranged on the second heat conducting board  532  at any positions, so long as they are symmetrical in structure such that the second heat conducting board  532  can be steadily mounted on an attachment. 
     The multiple lower heat conducting arms  534  are disposed on the upper surface  532   a  of the second heat conducting board  532  in the same arrangement as the upper heat conducting arms  520 . Two outermost lower heat conducting arms  534  of the multiple lower heat conducting arms  534  are provided with second sliding holes  534   a  and second screw holes  534   b  corresponding to the first screw holes  526  and the first sliding holes  528  on the upper heat conducting arms  520  respectively, wherein the hole diameter of the first sliding holes  528  and the second sliding holes  534   a  is larger than the hole diameter of the first screw holes  526  and second screw holes  534   b,  and the first sliding holes  528  and the second sliding holes  534   a  extend a distance along a direction vertical to the first heat conducting board  510  to form elongate holes with a run space. 
     In this embodiment, the resilient elements  536  comprise multiple first limit resilient elements  536   a  and multiple second limit resilient elements  536   b.  The multiple first limit resilient elements  536   a  are used to set around the first locating posts  516  and the second locating posts  532   c  to keep a distance between the first heat conducting board  510  and the heat conducting surface  531  of the heat conducting structure  530 . The multiple second limit resilient elements  536   b  are used to match the locking elements  538  to ensure that the upper heat conducting arms  520  and the lower heat conducting arms  534  are closely abutted with each other all the time. In this embodiment, the resilient elements  536  are coil springs. 
     In this embodiment, the locking elements  538  are bolts, which are used to slidably connect the first heat conducting board  510  and heat conducting structure  530 . 
     When assembled, first of all, the first limit resilient elements  536   a  are set around the first locating posts  516  and the second locating posts  532   c  respectively, then the first heat conducting board  510  is directly covered on the heat conducting structure  530  such that the upper heat conducting arm  520  and lower heat conducting arms  534  are alternately arranged, wherein the multiple upper heat conducting arm  520  are located on the same side of the lower heat conducting arms  534 . Next, a pressure is applied on the first heat conducting board  510  to cause a resilient deformation of the first limit resilient elements  536   a  to store an amount of elastic potential energy, an elastic force is provided by the elastic potential energy stored in the first limit resilient elements  536   a  to keep the position relationship between the first heat conducting board  510  and the heat conducting structure  530 . At the same time, the first screw holes  526  and the first sliding holes  528  on the upper heat conducting arm  520  are aligned with the second sliding holes  534   a  and the second screw holes  534   b  on the lower heat conducting arms  534 . Then, the locking elements  538  setting around second limit resilient elements  536   b  are locked into the first screw holes  526  and the second screw holes  534   b,  and ensure that the locking elements  538  pass into the first sliding holes  528  and the second sliding holes  534   a,  so that the upper heat conducting arms  520  and the lower heat conducting arms  534  move in the travel distance defined by the first sliding holes  528  and the second sliding holes  534   a.  A pretightening force is applied on the locking elements  538 , so that the second limit resilient elements  536   b  set around the locking elements  538  produce a resilient deformation to store an amount of elastic potential energy. The second limit resilient elements  536   b  provide a force applied on the upper heat conducting arms  520  and the lower heat conducting arms  534  through the elastic potential energy stored in the second limit resilient elements  536   b  to cause a trend of closing to each other of the upper heat conducting arms  520  and the lower heat conducting arms  534 , to ensure that the upper heat conducting arms  520  and the lower heat conducting arms  534  closely contact all the time to realize heat transfer. 
     With the heat conducting device  500  provided in this embodiment, the relative position between the heat conducting surface  531  of the heat conducting structure  530  and the first heat conducting board  510  is kept through the locking elements  538  and the first limit resilient elements  536   a.  When the distance between the heat conducting surface  531  of the heat conducting structure  530  and the first heat conducting board  510  is required to be adjusted, it is only needed to apply a pressure on the first heat conducting board  510  or release the pressure applied on the first heat conducting board  510  to realize the adjustment of the distance between the heat conducting structure  530  and the first heat conducting board  510 , so that accumulative tolerances produced in the manufacture of the electronic device can be compensated. Furthermore, through providing lower heat conducting arms  534  on second heat conducting board  532  which are abutted against upper heat conducting arms  520 , the heat conducting device provided in this embodiment may increase the contact surface for heat transfer between the heat conducting structure  530  and the first heat conducting board  510 , so that thermal resistance is reduced, and heat dispersion efficiency is further improved. 
     Referring to  FIG. 7 ,  FIG. 7  is a side view of a heat conducting device  600  provided according to a sixth embodiment of this invention. The structure of the heat conducting device  600  is similar to that of the heat conducting device  500  provided in the fifth embodiment, comprising a first heat conducting board  610  and a heat conducting structure  630 . The first heat conducting board  610  comprises at least one upper heat conducting arm  620  provided on one side surface of the first heat conducting board  610 . The heat conducting structure  630  directly faces the upper heat conducting arm  620  of the first heat conducting board  610  and slidably abuts against the upper heat conducting arm  620  to perform heat transfer through the contact surface between a lower heat conducting arm  634  on the heat conducting structure  630  and the upper heat conducting arm  620 . The heat conducting structure  630  comprises a heat conducting surface  631  and is used to keep the relative position between the first heat conducting board  610  and the heat conducting surface. The distance between the first heat conducting board  610  and the heat conducting surface  631  of the heat conducting structure  630  can be varied by means of relative sliding between the upper heat conducting arm  620  and the heat conducting structure  630 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  620  of the first heat conducting board  610  and the heat conducting structure  630 . The heat conducting device  600  provided in the sixth embodiment differs from the heat conducting device  500  provided in the fifth embodiment in the following aspects. 
     In this embodiment, the first locating posts  516 , the second locating posts  532   c  and the first limit resilient elements  536   a  set around the first locating posts  516  and the second locating posts  532   c  in the heat conducting device  500  in the fifth embodiment are omitted. Further, a first resilient element  650  arranged between the second surface  614  of the first heat conducting board  610  and the upper surface  632   a  of the second heat conducting board  632  is employed in this embodiment to keep the relative position between the first heat conducting board  610  and heat conducting surface  631  of the heat conducting structure  630 . In this embodiment, the first resilient element  650  is located in the space surrounded by the upper heat conducting arm  620  and the lower heat conducting arm  634  together. In this embodiment, the first resilient element  650  is a spring sheet. 
     The heat conducting device  600  provided in the sixth embodiment of this invention may realize the same functions of the heat conducting device  500  provided in the fifth embodiment. Furthermore, the heat conducting device  600  employs a first resilient element  650  to keep the relative position between the first heat conducting board  610  and the heat conducting surface  631  of the heat conducting structure  630 , so that the structure of the heat conducting device  600  is greatly simplified, and the manufacture cost of the heat conducting device  600  can be further reduced. 
     Referring to  FIG. 8 ,  FIG. 8  is a side view of a heat conducting device  700  provided according to a seventh embodiment of this invention. The structure of the heat conducting device  700  is similar to that of the heat conducting device  600  provided in the sixth embodiment, comprising a first heat conducting board  710  and a heat conducting structure  730 . The first heat conducting board  710  comprises at least one upper heat conducting arm  720  provided on one side surface of the first heat conducting board  710 . The heat conducting structure  730  is directly aligned to the upper heat conducting arm  720  of the first heat conducting board  710  and slidably abuts against the upper heat conducting arm  720  to perform heat transfer through the contact surface between the heat conducting structure  730  and the upper heat conducting arm  720 . The heat conducting structure  730  comprises a heat conducting surface  731  and is used to keep the relative position between the first heat conducting board  710  and the heat conducting surface. The distance between the first heat conducting board  710  and the heat conducting surface  731  of the heat conducting structure  730  can be varied by means of relative sliding between the upper heat conducting arm  720  and the heat conducting structure  730 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  720  of the first heat conducting board  710  and the heat conducting structure  730 . The heat conducting device  700  provided in the seventh embodiment differs from the heat conducting device  600  provided in the sixth embodiment in the following aspects. 
     In this embodiment, the locking elements  638  and the second limit resilient elements  636   b  in the sixth embodiment are further omitted. Furthermore, two second resilient elements  770  provided on the supper surface  732   a  of the second heat conducting board  732  are employed in this embodiment, the second resilient elements  770  are adjacent to the lower heat conducting arms  734  and are abutted against the first heat conducting board  710 , so that the upper heat conducting arms  720  on the first heat conducting board  710  are closely abutted against the lower heat conducting arms  734  of the heat conducting structure  730  to ensure that a contact surface for heat transfer always exists between the first heat conducting board  710  and the heat conducting structure  730 . In order to make the contact of the contact surfaces more sufficient, a heat conductive filler, such as heat conductive silica gel, etc may be filled between the contact surfaces of the first heat conducting board  710  and the heat conducting structure  730 . In this embodiment, the second resilient elements  770  are spring sheets, but not limited to spring sheets. 
     The heat conducting device  700  provided in the seventh embodiment of this invention may realize the same functions of the heat conducting device  600  provided in the sixth embodiment. Furthermore, the heat conducting device  700  employs two second resilient element  770  to keep the close abutting between the upper heat conducting arms  720  and the lower heat conducting arms  734 , not only realizing effective heat transfer between the upper heat conducting arms  720  and the lower heat conducting arms  734 , but also further simplifying the structure of the heat conducting device  700 , further reducing the manufacture cost of the heat conducting device  700 . 
     It may be understood that the first resilient element  750  may have other alternative solutions, referring to  FIG. 9 , the first resilient element  750  can be substituted by two resilient elements  780  disposed between the first heat conducting board  710  and the second heat conducting board  732 . In this embodiment, the resilient elements  780  are symmetrically disposed on the periphery of the region surrounded by the upper heat conducting arms  720  and the lower heat conducting arms  734 , but not limited to this region. The resilient elements  780  in this embodiment are metal coil springs, but not limited to metal coil springs. The resilient elements  780  may be substituted by elastic rubber or other elastic apparatus or elements. 
     It may be understood that, as shown in  FIG. 10 , if the first heat conducting board  710  of the heat conducting device  700  and the second heat conducting board  732  of the heat conducting structure  730  are reliably connected to a heat source  20  of an electronic device and a heat dispersion device or case  40  corresponding to the heat source  20  through screw connection, riveting, adherence and other connection manners, the first resilient element  750  or the resilient elements  780  of the heat conducting device  700  can be both omitted, such that the structure of the heat conducting device  700  can be simplified further. 
     Referring to  FIG. 11 ,  FIG. 11  is a side view of a heat conducting device  800  provided according to an eighth embodiment of this invention. The structure of the heat conducting device  800  is similar to that of the heat conducting device  700  provided in the seventh embodiment, comprising a first heat conducting board  810  and a heat conducting structure  830 . The first heat conducting board  810  comprises at least one upper heat conducting arm  820  provided on one side surface of the first heat conducting board  810 . The heat conducting structure  830  is directly aligned to the upper heat conducting arm  820  of the first heat conducting board  810  and slidably abuts against the upper heat conducting arm  820  to perform heat transfer through the contact surface between the heat conducting structure  830  and the upper heat conducting arm  820 . The heat conducting structure  830  comprises a heat conducting surface  831  and is used to keep the relative position between the first heat conducting board  810  and the heat conducting surface  831 . The distance between the first heat conducting board  810  and the heat conducting surface  831  of the heat conducting structure  830  can be varied by means of relative sliding between the upper heat conducting arm  820  and the heat conducting structure  830 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  820  of the first heat conducting board  810  and the heat conducting structure  830 . The heat conducting device  800  provided in the eighth embodiment differs from the heat conducting device  700  provided in the seventh embodiment in the following aspects. 
     The first resilient element  750  and second resilient elements  770  of the heat conducting device  700  provided in the seventh embodiment are substituted with multiple integrated resilient elements  850  in the heat conducting device  800  provided in the eighth embodiment of this invention. The resilient elements  850  can not only keep the position relationship between the first heat conducting board  810  and the heat conducting structure  830 , but also keep the close abutting between the upper heat conducting arms  820  and the lower heat conducting arms  834  to realize effective heat transfer between the first heat conducting board  810  and the heat conducting structure  830 . Each of the resilient elements  850  comprises a locating segment  852 , a supporting segment  854  connected to the locating segment  852 , and a resilient segment  856  connected to an end of the supporting segment  854 . The locating segment  852  is fixed on the upper surface  832   a  of the second heat conducting board  832 . The supporting segment  854  is connected to an end of the locating segment  852  in a substantially vertical manner A positive or negative tolerance is allowed for the angle between the supporting segment  854  and the locating segment  852 . The resilient segment  856  is connected to the end of the supporting segment  854  apart from the supporting segment  854 , and is tilted towards the second heat conducting board  832 . Corresponding to the titled resilient segment  856 , a slant  826  is provided on a side  824  of the upper heat conducting arm  820 . The slant  826  of the upper heat conducting arm  820  is abutted against the resilient segment  856  of a corresponding resilient element  850 . The resilient segment  856  applies an elastic force on the slant  826  of the upper heat conducting arm  820 , which can be decomposed into a push force perpendicular to the side  824  of the upper heat conducting arm  820  to keep the close abutting between the upper heat conducting arm  820  and the lower heat conducting arm  834 , and a push force perpendicular to the end side  822  of the upper heat conducting arm  820  to keep the position relationship between the first heat conducting board  810  and the heat conducting structure  830 . Therefore, the heat conducting device  800  provided in this embodiment may provide forces required to keep the position relationship between the first heat conducting board  810  and the heat conducting structure  830  and to keep the close abutting between the upper heat conducting arm  820  and the lower heat conducting arm  834 , so that the structure of the heat conducting device  800  can be simplified. Furthermore, heat transfer also can be realized through the large area contact between the resilient element  850  and the second heat conducting board  832 , the upper heat conducting arm  820 , so that thermal conductivity between the first heat conducting board  810  and the heat conducting structure  830  can be improved. Furthermore, in order to prevent the escape of the upper heat conducting arm  820  from the resilient element  850  under the elastic force of the resilient element  850 , the slant  826  is connected to the end side  822  of the upper heat conducting arm  820  through a transition surface  828  parallel to the side surface  824 , and a block  823  protruding from the transition surface  828  is provided at a position on the transition surface  828  adjacent to the end side  822 . The block  823  and the end of the resilient segment  856  of the resilient element  850  are abutted with each other to prevent the separation phenomenon of the upper heat conducting arm  820  and the resilient element  850 . 
     Referring to  FIG. 12 ,  FIG. 12  is a side view of a heat conducting device  900  provided according to a ninth embodiment of this invention. The heat conducting device  900  comprises a first heat conducting board  910  and a heat conducting structure  930 . The first heat conducting board  910  comprises at least one upper heat conducting arm  920  provided on a side surface of the first heat conducting board  910 . The heat conducting structure  930  is directly aligned to the upper heat conducting arm  920  of the first heat conducting board  910  and slidably abuts against the upper heat conducting arm  920  to perform heat transfer through the contact surface between the heat conducting structure  930  and the upper heat conducting arms  920 . The heat conducting structure  930  comprises a heat conducting surface  931  and is used to keep a relative position between the first heat conducting board  910  and the heat conducting surface. The distance between the first heat conducting board  910  and the heat conducting surface  931  of the heat conducting structure  930  can be varied by means of relative sliding between the upper heat conducting arms  920  and the heat conducting structure  930 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  920  of the first heat conducting board  910  and the heat conducting structure  930 . 
     The first heat conducting board  910  comprises a first surface  912  and a second surface  914  corresponding to the first surface  912 . 
     This embodiment comprises multiple upper heat conducting arms  920 , containing a first upper heat conducting arm  921 , two second upper heat conducting arms  923  and a third upper heat conducting arm  925 . The first upper heat conducting arm  921 , the second upper heat conducting arms  923  and the third upper heat conducting arm  925  are sequentially provided on a second surface  914  of the first heat conducting board  910 . A first limit protrusion  921   a  protruding from a side surface  924  and flush with an end surface  922  of the first upper heat conducting arm  921  is provided on the side surface  924  of the first upper heat conducting arm  921  adjacent to an edge of the first heat conducting board  910 . The first limit protrusion  921   a  is used to match with a corresponding limit structure on the heat conducting structure  930  to restrict the position between the first heat conducting board  910  and the heat conducting structure  930 . A first groove  921   b  is provided on the end side  922  of the first upper heat conducting arm  921  to receive the limit device of the heat conducting structure  930 . The two second upper heat conducting arms  923  are provided on one side of the first upper heat conducting arm  921  with an interval. The third upper heat conducting arm  925  is provided on the first heat conducting board  910  on one side of the second upper heat conducting arms  923  apart from the first upper heat conducting arm  921 . A second groove  925   a  adjacent to the second surface  914  of the first heat conducting board  910  is provided on a side surface  924  of the third upper heat conducting arm  925  facing the first upper heat conducting arm  921 , a second limit protrusion  925   b  is formed on one end of the second groove  925   a  apart from the first heat conducting board  910 . The second limit protrusion  925   b  is used to match a corresponding limit structure on the heat conducting structure  930  to restrict the position between the first heat conducting board  910  and the heat conducting structure  930 . 
     Referring to  FIG. 13 ,  FIG. 13  is a perspective schematic view of the heat conducting structure  930  provided in the ninth embodiment of this invention. 
     The heat conducting structure  930  comprises a second heat conducting board  932 , multiple lower heat conducting arms  934  formed on the second heat conducting board  932 , multiple resilient elements  936  and multiple locking elements  938 . 
     The second heat conducting board  932  comprises an upper surface  932   a  and a lower surface  932   b  corresponding to the upper surface  932   a.  In this embodiment the heat conducting surface  931  and the lower surface  932   b  of the second heat conducting board  932  are the same surface. The second heat conducting board  932  is square in shape, two lips  932   d  are formed on diagonal positions of the second heat conducting board  932  respectively, with two through holes  932   e  provided on the two lips  932   d  for securing the second heat conducting board  932  to an attachment, such as a heat source or a heat dispersing shield in an electronic device by means of fasteners passing through the through holes  932   e.    
     The structure and arrangement of the lower heat conducting arms  934  are as same as that of the upper heat conducting arms  920 . The multiple lower heat conducting arms  934  comprises a first lower heat conducting arm  934   a,  two second lower heat conducting arms  934   b,  and a third lower heat conducting arm  934   c.  The first lower heat conducting arm  934   a,  the second lower heat conducting arms  934   b,  and the third lower heat conducting arm  934   c  are sequentially provided on the upper surface  932   a  of the second heat conducting board  932 . A third limit protrusion  934   d  corresponding to and capable of clipping with the second limit protrusion  925   b  on the third upper heat conducting arm  925  protrudes from a side surface of the first lower heat conducting arm  934   a  adjacent to an edge of the second heat conducting board  932 , and a third groove  934   e  is provided on the first lower heat conducting arm  934   a  at a position adjacent to the third limit protrusion  934   d.  The two second lower heat conducting arms  934   b  are provided on the second heat conducting board  932  on one side of the first lower heat conducting arm  934   a  at a certain interval. The third lower heat conducting arm  934   c  is provided on the second heat conducting board  932  on one side of the second lower heat conducting arms  934   b  apart from the first lower heat conducting arm  934   a.  A fourth groove  934   f  is formed on the third lower heat conducting arm  934   c,  corresponding to the first limit protrusion  921   a  on the first upper heat conducting arm  921 , a fourth limit protrusion  934   g  capable of clipping with the first limit protrusion  921   a  is formed on one end of the fourth groove  934   f  apart from the upper surface  932   a  of the second heat conducting board  932 . 
     The multiple resilient elements  936  are disposed in the first groove  921   b  and the third groove  934   e  respectively. Each of the resilient elements  936  comprises a fixing portion  936   a,  two first resilient arms  936   b  symmetrically formed on opposite sides of the fixing portion  936   a,  and a second resilient arm  936   c  provided on the fixing portion  936   a  and located at a side edge between the two first resilient arms  936   b.  The two first resilient arms  936   b  are folded an angle towards a direction vertical to the fixing portion  936   a,  preferably, the folding angle causes the folded first resilient arms  936   b  abutted against the first heat conducting board  910  and the second heat conducting board  932  when the second limit protrusion  925   b  is clipped with the third limit protrusion  934   d  and the first limit protrusion  921   a  is clipped with the fourth limit protrusion  934   g.  The second resilient arm  936   c  is folded an angle towards a direction opposite to the folding direction of the first resilient arms  936   b,  preferably, an angle causing that the second resilient arm  936   c  can abut against an adjacent upper heat conducting arm  920  or a lower heat conducting arm  934  when the first heat conducting board  910  is matched to the heat conducting structure  930 . 
     When assembled, first of all, the fixing portion  936   a  of a resilient element  936  is secured on the underside of the first groove  921   b  or the third groove  934   e  through locking elements  938 . Then, the first resilient arms  936   b  and the second resilient arm  936   c  of the resilient elements  936  is compressed, the first limit protrusion  921   a  and the second groove  925   a  of the first heat conducting board  910  are aligned with the fourth groove  934   f  and the third limit protrusion  934   d  of the heat conducting structure  930 , and the first limit protrusion  921   a  slides into the fourth groove  934   f  from one side of the heat conducting structure  930 , the third limit protrusion  934   d  slides into the second groove  925   a,  so that the first limit protrusion  921   a  and the second limit protrusion  925   b  of the first heat conducting board  910  clip with the fourth limit protrusion  934   g  and the third limit protrusion  934   d  of the heat conducting structure  930  respectively. Finally, the first resilient element  936   b  and the second resilient element  936   c  are released such that the first resilient element  936   b  abut against first heat conducting board  910  or second heat conducting board  932  corresponding to first resilient element  936   b  to keep the relative position between the first heat conducting board  910  and the heat conducting structure  930 , at the same time, the second resilient element  936   c  abuts against the adjacent second upper heat conducting arm  920  or second lower heat conducting arm  934  to provide an elastic force causing the multiple upper heat conducting arms  920  and lower heat conducting arms  932  closely abutted to ensure that a contact surface for heat transfer always exists between the upper heat conducting arms  920  and the lower heat conducting arms  934 . The assembly manner of the heat conducting device  900  is merely one manner for the introduction of this embodiment, and other assembly manners can be employed, such as the first heat conducting board  910  is directly disposed above the heat conducting structure  930  to make the spaces between the upper heat conducting arms  920  corresponding to the spaces between the lower heat conducting arms  934 , then a press is applied on the first heat conducting board  910  by which the first resilient arms  936   b  and the second resilient arm  936   c  of the resilient element  936  produce elastic deformations, as the upper heat conducting arms  920  gradually insert into the spaces between the lower heat conducting arms  934 , the second resilient element  936   c  abuts against the adjacent second upper heat conducting arm  920  or second lower heat conducting arm  934  and produces an elastic deformation, a trend of relative movement exists between the first heat conducting board  910  and the adjustable heat conducting structure  930  under the effect of the elastic force of the second resilient element  936   c,  with such a trend of movement, the first limit protrusion  921   a  and the second limit protrusion  925   b  of the first heat conducting board  910  clip with the fourth limit protrusion  934   g  and the third limit protrusion  934   d  of the heat conducting structure  930  respectively to complete the assembly of the heat conducting device  900 . 
     The heat conducting device  900  provided in this embodiment may keep the relative position between the first heat conducting board  910  and the heat conducting structure  930 , and ensure that a contact surface for heat transfer always exists between the first heat conducting board  910  and the heat conducting structure  930  through integrated resilient elements  936 , so as to realize an adjustable distance between the first heat conducting board  910  and the heat conducting structure  930  and make sure good heat transfer property at the same time. Furthermore, employing integrated resilient elements  936  may simplify the structure of the heat conducting device  900  and reduce cost. 
     Referring to  FIG. 14 ,  FIG. 14  is a side view of a heat conducting device  1000  provided according to a tenth embodiment of this invention. The heat conducting device  1000  comprises a first heat conducting board  1010  and a heat conducting structure  1030 . The first heat conducting board  1010  comprises at least one upper heat conducting arm  1020  provided on a side surface of the first heat conducting board  1010 . The heat conducting structure  1030  directly faces the upper heat conducting arm  1020  of the first heat conducting board  1010  and slidably abuts against the upper heat conducting arm  1020  to perform heat transfer through the contact surface between the heat conducting structure  1030  and the upper heat conducting arms  1020 . The heat conducting structure  1030  comprises a heat conducting surface  1031  and is used to keep a relative position between the first heat conducting board  1010  and the heat conducting surface. The distance between the first heat conducting board  1010  and the heat conducting surface  1031  of the heat conducting structure  1030  can be varied by means of relative sliding between the upper heat conducting arms  1020  and the heat conducting structure  1030 , at the same time, it is ensured that a contact surface for heat transfer always exists between the upper heat conducting arm  1020  of the first heat conducting board  1010  and the heat conducting structure  1030 . 
     The first heat conducting board  1010  comprises a first surface  1012  and a second surface  1014  corresponding to the first surface  1012 . 
     This embodiment comprises multiple upper heat conducting arms  1020 , containing a first upper heat conducting arm  1021 , two second upper heat conducting arms  1023  and a third upper heat conducting arm  1025 . The first upper heat conducting arm  1021 , the second upper heat conducting arms  1023  and the third upper heat conducting arm  1025  are sequentially provided on a second surface  1014  of the first heat conducting board  1010 . A first limit protrusion  1021   a  protruding from a side surface  1024  and flush with an end surface  1022  of the first upper heat conducting arm  1021  is provided on the side surface  1024  of the first upper heat conducting arm  1021  adjacent to an edge of the first heat conducting board  1010 . The first limit protrusion  1021   a  is used to match with a corresponding limit structure on the heat conducting structure  1030  to restrict the position between the first heat conducting board  1010  and the heat conducting structure  1030 . A first trench  1021   b  is provided on the first limit protrusion  1021   a  along a direction perpendicular to the first heat conducting board  1010 , the depth of which is less than the height of the first limit protrusion  1021   a  with respect to the side surface  1024  where the first limit protrusion  1021   a  locates. The first trench  1021   b  is used for guiding and position limiting during the assembly of the first heat conducting board  1010  and the heat conducting structure  1030 . A first slant  1024   a  is formed on the first upper heat conducting arm  1021  on a side surface  1024  corresponding to the side surface where the first trench  1021   b  is formed. A first convex bar  1021   c  running through the first slant  1024   a  along a direction parallel to the extending direction of the longer side of the end side  1022  of the first upper heat conducting arm  1021  is formed at the middle portion of the first slant  1024   a  of the first upper heat conducting arm  1021 . The two second upper heat conducting arms  1023  are provided on the first heat conducting board  1010  on one side of the first upper heat conducting arm  1021  with an interval. A second slant  1023   a  parallel to the first slant  1024   a  is formed on each of the second upper heat conducting arms  1023 . The third upper heat conducting arm  1025  is provided on the first heat conducting board  1010  on one side of the second upper heat conducting arms  1023  apart from the first upper heat conducting arm  1021 . A first groove  1025   a  adjacent to the second surface  1014  of the first heat conducting board  1010  is provided on a side surface of the third upper conducting arm  1025  which facing the slant  1024   a  of the first upper heat conducting arm  1021 . A second limit protrusion  1025   b  is formed on one end of the first groove  1025   a  apart from the first heat conducting board  1010 . The second limit protrusion  1025   b  is used to match a corresponding limit structure on the heat conducting structure  1030  to keep the position between the first heat conducting board  1010  and the heat conducting structure  1030 . 
     Referring to  FIG. 15 ,  FIG. 15  is a perspective schematic view of the heat conducting device  1030  provided in the tenth embodiment of this invention. 
     The heat conducting device  1030  comprises a second heat conducting board  1032 , multiple lower heat conducting arms  1034  formed on the second heat conducting board  1032  and multiple resilient elements  1036 . 
     The second heat conducting board  1032  comprises an upper surface  1032   a  and a lower surface  1032   b  corresponding to the upper surface  1032   a.  In this embodiment the heat conducting surface  1031  and the lower surface  1032   b  of the second heat conducting board  1032  are the same surface. The second heat conducting board  1032  is square in shape, two lips  1032   d  are formed on diagonal positions of the second heat conducting board  1032  respectively, with two through holes  1032   e  provided on the two lips  1032   d  for securing the second heat conducting board  1032  to an attachment, such as a heat source or a heat dispersing shield in an electronic device by means of fasteners passing through the through holes  1032   e.    
     The structure and arrangement of the lower heat conducting arms  1034  are as same as that of the upper heat conducting arms  1020 . The multiple lower heat conducting arms  1034  comprise a first lower heat conducting arm  1034   a,  two second lower heat conducting arms  1034   b,  and a third lower heat conducting arm  1034   c.  The first lower heat conducting arm  1034   a,  the second lower heat conducting arms  1034   b,  and the third lower heat conducting arm  1034   c  are sequentially provided on the upper surface  1032   a  of the second heat conducting board  1032 . A third limit protrusion  1034   d  corresponding to and capable of clipping with the second limit protrusion  1025   b  on the third upper heat conducting arm  1025  protrudes from a side surface of the first lower heat conducting arm  1034   a  adjacent to an edge of the second heat conducting board  1032 . A second trench  1034   e  is provided on the third limit protrusion  1034   d  on a side corresponding to an edge of the second heat conducting board  1032 . The width of the second groove  1034   e  is larger than the length of the third upper heat conducting arm  1025  on the first heat conducting board  1010  to accommodate the third upper heat conducting arm  1025 . A third slant  1034   h  is formed on another side of the first lower heat conducting arm  1034   a  opposite to side where the second groove  1034   e  locates, a second convex bar  1034   i  is formed on the third slant  1034   h  running through the third slant  1034   h  along the direction of a longer cross line between the first lower heat conducting arm  1034   a  and the second heat conducting board  1032 . The two second lower heat conducting arms  1034   b  are provided on the second heat conducting board  1032  on one side of the first lower heat conducting arm  1034   a  at a certain interval, wherein a fourth slant  1034   g  parallel to the third slant  1034   h  is formed on each of the second lower heat conducting arms  1034   b.  The third lower heat conducting arm  1034   c  is provided on the second heat conducting board  1032  on one side of the second lower heat conducting arms  1034   b  apart from the first lower heat conducting arm  1034   a.  A second groove  1034   f  is formed on the third lower heat conducting arm  1034   c  corresponding to the first limit protrusion  1021   a  on the first upper heat conducting arm  1021 , a fourth limit protrusion  1034   k  capable of clipping with the first limit protrusion  1021   a  is formed on one end of the second groove  1034   f  apart from the upper surface  1032   a  of the second heat conducting board  1032 . 
     The resilient elements  1036  of this embodiment are clamp springs, which each of the resilient elements  1036  comprises a dome resilient portion  1036   a  and clip portions  1036   b  extending from opposite sides of the resilient portion  1036   a  and bent in opposite directions, there is a distance between the ends of the two clip portions  1036   b.  The multiple resilient elements  1036  clip on the first convex bar  1021   c  of the first heat conducting board  1010  and second convex bar  1034   i  of the adjustable heat conducting structure  1030  through their clip portions  1036   b  respectively. 
     When assembled, the first heat conducting board  1010  is disposed above the heat conducting structure  1030 , making the spaces between the upper heat conducting arms  1020  correspond to the spaces between the lower heat conducting arms  1034 , and the third upper heat conducting arm  1025  and the third lower heat conducting arm  1034   c  relatively slide along the second groove  1034   e  of the first lower heat conducting arm  1034   a  and the first trench  1021   b  of the first upper heat conducting arm  1021 , so that the resilient elements  1036  clipped on the first convex bar  1021   c  and second convex bar  1034   i  abut against the second slants  1023   a  of their adjacent upper heat conducting arms  1020  and the fourth slants  1034   g  of the lower heat conducting arms  1034  via the resilient portion  1036   a.  Then, a press is applied on the first heat conducting board  1010 , the resilient portions  1036   a  of the resilient elements  1036  produce a elastic deformation under the press, and a elastic force due to the elastic deformation of the resilient portions  1036   a  may cause a trend of mutual separation between the first heat conducting board  1010  and the heat conducting structure  1030  in the direction perpendicular to the first heat conducting board  1010 , and a trend of mutual close in the direction parallel to the first heat conducting board  1010 . As the upper heat conducting arms  1020  are inserted into the spaces between the lower heat conducting arms  1034  step by step, the first limit protrusion  1021   a  and the second limit protrusion  1025   b  of the first heat conducting board  1010  clip with the fourth limit protrusion  1034   k  and the third limit protrusion  1034   d  of the heat conducting structure  1030  under the elastic force of the resilient elements  1036  to complete the assembly of the device  1000 . 
     The heat conducting device  1000  provided in this embodiment may keep the relative position between the first heat conducting board  1010  and the heat conducting structure  1030 , and ensure that a contact surface for heat transfer always exists between the first heat conducting board  1010  and the heat conducting structure  1030  through resilient elements  1036  having a simple structure, so as to realize an adjustable distance between the first heat conducting board  1010  and the heat conducting structure  1030  and make sure good heat transfer property at the same time, further simplifying the structure of the heat conducting device  1000  and lowering cost. 
     It may be understood that the structure of the resilient elements  1036  is not limited to that given in this embodiment, and may be any structure implementing the functions of the resilient elements  1036  based on the concept of this invention, in another embodiment shown in  FIG. 16  for example, the resilient elements  1036  may be substituted with “Z” shaped or “V” shaped resilient elements  1038 , which may abut against the second slants  1023   a  of their adjacent upper heat conducting arms  1020  and the fourth slants  1034   g  of the lower heat conducting arms  1034  with their mutually apart resilient arms  1038   a  to provide a elastic force capable of keeping the position relationship between the first heat conducting board  1010  and the adjustable heat conducting structure  1030 , and ensuring that a contact surface for heat transfer always exists between the upper heat conducting arms  1020  and the lower heat conducting arms  1034 . 
     All of the heat conducting devices provided in the above embodiments of this invention may be used in various electronic products for heat dispersion. In order to illustrate the arrangement of heat conducting devices of this invention in electronic products, the heat conducting device  500  provided in the fifth embodiment of this invention is merely used for illustrate its application in an electronic device. 
     Referring to  FIG. 17 ,  FIG. 17  is an electronic device  1100  in which a heat conducting device  500  is applied provided in the eleventh embodiment of this invention. 
     The electronic device comprises a circuit board  1110 , multiple chips  1120  mounted on the circuit board  1110 , a heat dispersing shield  1130  provided on the circuit board  1110  for accommodating the multiple chips  1120 , a heat dispersion device  1140  on the heat dispersing shield  1130 , one or more heat conducting devices  500  disposed between the chips  1120  and the heat dispersing shield  1130 . The second heat conducting boards  532  of the heat conducting structures  530  of the heat conducting devices  500  are fixed on the inner sides of the heat dispersing shield  1130  corresponding to the chips  1120 , the heat conducting surfaces  531  of the heat conducting structures  530  are closely attached to the heat dispersing shield  1130 . The first heat conducting boards  510  of the heat conducting devices  500  are arranged and closely attached on the surfaces of the chips  1120 . When the distances between the multiple chips  1120  and the heat dispersing shield  1130  are different, good heat transfer may be realized through independently adjusting the distances between the first heat conducting boards  510  and the heat conducting surfaces  531  with the heat conducting structures  530  of the heat conducting devices  500  to cause the heat conducting devices  500  to keep good contact between the chips  1120  and the heat dispersing shield  1130  all the time. For more sufficient contact between the heat conducting structures  530  and the heat dispersing shield  1130 , and thus better heat transfer effect, heat dispersion convexes  1150  can be provided between the heat conducting structures  530  and the heat dispersing shield  1130 . 
     Furthermore, it may be understood that in order to provide good heat conduction property for a heat conducting device provided in the above embodiment of this invention and an electronic device using the heat conducting device, a heat conducting filler or a conductive interface material can be filled between the contact surfaces for heat transfer of the heat conducting device and the electronic device using the heat conducting device. 
     The heat conducting device employed in the electrical device provided in the embodiment of this invention may adjust its own thickness according to use environments and manufacture errors to adapt variations in distance between a heat source and the heat dispersion structure, so as to ensure effective heat dispersion of the electronic device. Further, the heat conducting device provided in the embodiment of this invention employs high thermal conductivity materials for heat conduction, so that heat conduction efficiency can be greatly improved, at the same time, the structure of the heat conducting device provided in the embodiment of this invention is simple and easy to implement, thus, cost can be reduced and energy can be saved through large scale production. 
     The description above is merely preferable embodiments of this invention, but is not intended to limit this invention. Any modification, equivalent or improvement in the spirit and principle of this invention should be covered in the scope of this invention.