Abstract:
A heat dissipation device ( 10 ) includes a first heat sink ( 20 ), a second heat sink ( 30 ) and a heat pipe ( 40 ) transferring heat from the first heat sink to the second heat sink. A bracket ( 50 ) includes a first end ( 51 ) attached to the first heat sink and a second end ( 52 ) attached to the second heat sink, thus enhancing the strength and stability of the heat dissipation device.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a heat dissipation device with two heat sinks for electronics particularly a heat dissipation device having a bracket to fix and interconnect the two heat sinks.  
       DESCRIPTION OF RELATED ART  
       [0002]     With the continued development of computer technology, electronic packages such as computer central processing units (CPUs) are generating more and more heat that needs to be dissipated immediately to avoid damage to the circuitry. Conventional heat dissipating devices such as heat sinks mounted onto the CPU are not sufficiently effective at dissipating heat to cope with modern circuitry. New heat dissipation devices featuring twin heat sinks are increasingly being used to enhance efficiency of these electronic packages. US Publication No. 2003/0183373 A1 shows an example of this kind of heat dissipation device. The heat dissipation device includes a first heat sink, a second heat sink and a heat pipe conducting heat from the first heat sink to the second heat sink. However, this type of the heat dissipation device is not sturdy. The two heat sinks only interconnect via the heat pipe. When an external force acts on heat dissipation device, the heat pipe is likely to deform, thereby reducing the heat transfer performance of the heat pipe and thus also reducing the heat dissipating efficiency of the whole heat dissipation device.  
       SUMMARY OF INVENTION  
       [0003]     According to a preferred embodiment of the present invention, a heat dissipation device comprises a first heat sink, a second heat sink and a heat pipe transferring heat from the first heat sink to the second heat sink. A bracket includes a first end attached to the first heat sink and a second end attached to the second heat sink, thus enhancing the strength and stability of the heat dissipation device.  
         [0004]     Other advantages and novel features of the present invention will become more apparent from the following detailed description of the preferred embodiment when taken in conjunction with the accompanying drawings, in which: 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0005]      FIG. 1  is an assembled view of a heat dissipation device according to a preferred embodiment of the present invention; and  
         [0006]      FIG. 2  is an exploded, isometric view of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0007]     Referring to  FIGS. 1-2 , a heat dissipation device  10  in accordance with a preferred embodiment of the present invention is illustrated. The heat dissipation device  10  mainly comprises a first heat sink  20 , a second heat sink  30  and a heat pipe  40  conducting heat from the first heat sink  20  to the second heat sink  30 . A bracket  50  connects the first heat sink  20 , the heat pipe  40  and the second heat sink  30 , so as to reinforce the whole structure of the heat dissipation device  10 .  
         [0008]     The first heat sink  20  comprises a base  22 , two spaced groups of fins  24  extending upwardly from the base  22  and a separating member  28  mounted between the two groups of fins  24 . A connection area  26  of the base  22  is formed between the two groups of fins  24 . A groove  260  is defined in the connection area  26  of the base  22  for receiving an evaporating portion  42  of the heat pipe  40 . The separating member  28  is mounted on the connection area  26  of the first heat sink  20 . The separating member  28  comprises a base  282  parallel to the base  22  and a plurality of fins  284  extending upwardly from the base  282  thereof. Each of the fins  284  is parallel to each of the fins  24  of the first heat sink  20 . The base  282  of the separating member  28  has a same length as the base  22  of the first heat sink  20  along a lateral direction. A length of the fins  284  is shorter than that of the base  282  such that a mating area  281  is formed at a top edge of the base  282 . A pair of threaded holes  283  is defined in the mating area  281  of the base  282 . A groove  280  corresponding to the groove  260  is defined in a bottom of the base  282 . The groove  280  and the groove  260  cooperatively form a channel for receiving the evaporating portion  42  of the heat pipe  40 .  
         [0009]     The second heat sink  30  comprises a plurality of fins  34  spaced from and snapped (i.e. connected) with each other. The fins  34  are perpendicular to the base  22  of the first heat sink  20 . A through hole  340  is defined in the fins  34  for receiving a condensing portion  44  of the heat pipe  40 .  
         [0010]     The bracket  50  is made from any high strength material such as metal, metal alloy, plastic or any other suitable material. The bracket  50  comprises two free ends  51 ,  52  and a connecting arm  53 . The free end  51  parallel to the base  22  of the first heat sink  20  is mounted on the mating area  281  of the separating member  28  of the first heat sink  20  and the free end  52  parallel to the fins  34  of the second heat sink  30  is mounted on the second heat sink  30 . The free end  51  defines a pair of mounting holes  513  corresponding to the threaded holes  283  of the mating area  281  of the first heat sink  20 . The free end  52  is substantially perpendicular to the free end  51 , and defines a through hole  520  therein. The through hole  520  has an annular sidewall  522  extending perpendicularly from an edge thereof. The connecting arm  53  has a bend  530  at a substantially central portion thereof.  
         [0011]     In assembly, the grooves  280 ,  260 , the connection area  26 , an inner surface of the through hole  340  and the sidewall  522  are coated with solder. The evaporating portion  42  of the heat pipe  40  is soldered into the channel of the first heat sink  20  formed by the grooves  260 ,  280 . The free end  52  of the bracket  50  abuts against a lateral side of an outmost fin  34  of the second heat sink  30  near the first heat sink  20  and the through hole  520  of the bracket  50  is aligned with the through hole  340  of the second heat sink  30 . The condensing portion  44  of the heat pipe  40  is brought to extend in the through holes  340 ,  520  and is soldered therein so that the second heat sink  30  and the bracket  50  are connected together via the condensing portion  44  of the heat pipe  40  soldered to the free end  52  of the bracket  50  and the fins  34 . The free end  51  of the bracket  50  is positioned on the mating area  281  of the separating member  28  of the first heat sink  20 . A pair of screws  54  extends through the mounting holes  513  of the bracket  50  and screw into the threaded holes  283  of the first heat sink  20 . Thus the first heat sink  20  and the second heat sink  30  are immovably connected together. In a further preferred embodiment, the free end  52  is also soldered to the lateral side of the outmost fin  34  of the second heat sink  30 .  
         [0012]     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.