Abstract:
A clip is adapted for securing a heat sink on a printed circuit board (PCB). The clip includes a linking portion, an operating portion, a handle, and a pressing portion. The linking portion is located at a lateral side of the heat sink. The operating portion pivotally engages with the linking portion and the heat sink. The handle connects the operating portion. The pressing portion connects the linking portion. A fastener mounted on the PCB extends through the heat sink and the pressing portion. The pressing portion is slidable from a first position to a second position. When the pressing portion is in the second position the handle is operable to drive the operating portion to move upwardly and urge the pressing portion to move along the fastener until the pressing portion abuts against a top portion of the fastener and simultaneously presses the heat sink.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a heat sink assembly having a clip, which can easily and accurately attach a heat sink to a printed circuit board. 
         [0003]    2. Description of Related Art 
         [0004]    A typical heat sink assembly cools an electronic component mounted on a printed circuit board (PCB). The heat sink assembly generally includes a heat sink contacting the electronic component to facilitate dissipation of heat therefrom, and a clip fastening the heat sink to the electronic device. The clip comprises a pressing portion, and a plurality of hooks extending from a periphery of the pressing portion. The pressing portion presses the heat sink. The hooks are engaged with engaging portions of the PCB one by one using a mounting tool, to mount the heat sink on the PCB. This is very time-consuming and troublesome. 
         [0005]    What is needed, therefore, is a heat sink assembly having a clip, wherein the clip can easily and accurately attach a heat sink to a printed circuit board. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is an assembled view of a heat sink assembly in accordance with an embodiment of the present disclosure, showing a clip of the heat sink assembly unlocked. 
           [0007]      FIG. 2  is similar to  FIG. 1 , but showing the clip locked. 
           [0008]      FIG. 3  is an exploded view of the heat sink assembly of  FIG. 1 . 
           [0009]      FIG. 4  is an inverted view of  FIG. 3 . 
           [0010]      FIG. 5  is an exploded view of the clip of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    Referring to  FIGS. 1-3 , an embodiment of a heat sink assembly is shown. The heat sink assembly comprises a heat sink  30 , and a clip  50  engaging with the heat sink  30 . The heat sink  10  thermally contacts an electronic component  11  mounted on a printed circuit board (PCB)  10 . The clip  50  spans over the heat sink  30  and also extends through the heat sink  30  and engages with four fasteners  13  which are located on four corners of the PCB  10 , thereby securing the heat sink  30  on the PCB  10 . 
         [0012]    Referring to  FIGS. 4-5  also, the clip  50  comprises two spaced connecting portions  51 , two linking portions  54  located above the two connecting portions  51 , two supporting portions  57  interconnected between the two linking portions  54 , a pressing portion  53  supported by the supporting portions  57 , two operating portions  55  interconnecting corresponding connecting portions  51  and linking portions  54 , respectively, and a handle  58  interconnecting the two operating portions  55 . 
         [0013]    The two connecting portions  51  connect with the heat sink  30 . Each of the connecting portions  51  has a U-shaped configuration. Each connecting portion  51  comprises an elongated connecting plate  511  and two elongated extending plates  513  extending perpendicularly and upwardly from lateral sides of the connecting plate  511 . The connecting plate  511  connects with the heat sink  30 . One of the extending plates  513  pivotally engages with the operating portion  55 . The connecting plate  511  is parallel to the corresponding linking portion  54 . 
         [0014]    Each of the operating portions  55  is a linkage, and comprises two first rods  553 , two second rods  554 , and two third rods  555 . Lower ends of the first rods  553  pivotally engage with front and rear ends of the extending plate  513  of the connecting portion  51 , and upper ends of the first rods  553  pivotally engage with lower ends of the second rods  554 , respectively. The first and second rods  553 ,  554  join at a point A and a point B, respectively. Upper ends of the second rods  554  pivotally engage with front and rear ends of the linking portion  54 , respectively. The two third rods  555  are generally aligned with each other end-to-end albeit slightly offset from each other. Outer ends of the third rods  555  pivotally engage with the first and second rods  553 ,  554  at the point A and the point B respectively, and inner ends of the third rods  555  are pivotally joined to each other at a point C. 
         [0015]    The handle  58  integrally extends from the inner ends of the two rearmost third rods  555  of the two operating portions  55 , slantwise from the points C. Thus movement of the handle  58  directly brings movement of the two rearmost third rods  555 . In particular, the handle  58  has a U-shaped configuration, and comprises two connecting arms  581  integrally extending from the two rearmost third rods  555 , and an operating arm  583  interconnecting two ends of the connecting arms  581 . 
         [0016]    The pressing portion  53  is an elastic element. The pressing portion  53  comprises two pressing plates  531 , and a joining plate  533  sandwiched between the pressing plates  531  and connecting central portions of the pressing plates  531 . Each of the pressing plates  531  comprises an elongated pressing section  5311 , and two inverted U-shaped engaging sections  5313  extending outwardly from lateral ends of the pressing section  5311 . The joining plate  533  is an elongated sheet and perpendicular connects with central portions of the two pressing sections  5311  of the two pressing plates  531 . Each of the engaging sections  5313  defines a first through hole  5314  and a second through hole  5315 . The first through hole  5314  communicates with and is aligned with the second through hole  5315 . A bore diameter of the first through hole  5314  is larger than that of the second through hole  5315 . The fasteners  13  are extended through the first through holes  5314 , and are then offset to the second through holes  5315  by pushing the joining plate  533 . Thereby, the fasteners  13  are engaged with the pressing portion  53 . 
         [0017]    Each of the supporting portions  57  comprises an elongated supporting plate  571 , and two elongated baffle plates  573  extending perpendicularly and upwardly from front and rear ends of the supporting plate  571 . The pressing plate  531  is sandwiched between the two baffle plates  573 . An inverted T-shaped groove  5731  is defined in a central portion of an inner one of the baffle plates  573  (which is nearest to the other supporting portion  57 ). The joining plate  533  is inserted in a side of the groove  5731  and abuts against the baffle plate  573 . Thus, the pressing portion  53  is secured on the supporting portion  57 . 
         [0018]    Referring to  FIG. 3  again, each of the fasteners  13  is a metallic pole. Each fastener  13  comprises an extending portion  131  perpendicular connecting with the PCB  10 , an engaging portion  133 , and a head  135 . The engaging portion  133  extends upwardly from a top end of the extending portion  131 . The head  135  is located at a top end of the engaging portion  133 . The extending portion  131 , the engaging portion  133  and the head  135  are cylindrical. A diameter of the engaging portion  133  is smaller than that of the extending portion  131  and the head  135 . The diameter of the extending portion  131  approaches that of the head  135 . The diameter of the extending portion  131  is smaller the bore diameter of the first through hole  5314  and larger than the bore diameter of the second through hole  5315  of the pressing plate  531 . 
         [0019]    The heat sink  30  is integrally made of metal with high heat conductivity, such as copper, aluminum or an alloy thereof. The heat sink  30  comprises a rectangular base  31 , and a plurality of fins  33  extending upwardly from a top surface of the base  31 . The fins  33  are parallel to and spaced from each other. Two elongated ears  35  extend outwardly from lateral ends of the base  31 , to engage with the two connecting portions  51  of the clip  50 . Front and rear portions of each fin  33  are shorter than a central portion of the fin  33 . Thus, two L-shaped steps  37  are defined at front and rear top ends of the heat sink  30 . The two steps  37  support the two supporting portions  57  of the clip  50 . A rectangular recess  36  is defined in a central portion of a top end of the heat sink  30 , to receive the joining plate  533  of the pressing portion  53  therein. Four receiving spaces  38  are defined near four corners of the heat sink  30 . The receiving spaces  38  are provided by certain of the fins  33  which have only central portions and no front or rear portions. The fasteners  13  extend through four through holes  39  of the base  31  and the receiving spaces  38  to engage with the pressing portion  53  of the clip  50 . 
         [0020]    Referring to  FIGS. 1-2  again, when the heat sink assembly is assembled, the two operating portions  55  span over the heat sink  30 . The two connecting plates  511  of the two connecting portions  51  are secured on the two ears  35  of the heat sink  30 . The two supporting plates  571  of the two supporting portions  57  abut against the steps  37  of the heat sink  30 , respectively. The two linking portions  54  are located at opposite lateral sides of the heat sink  30  to sandwich the heat sink  30  therebetween. The pressing portion  53  is located at a top of the heat sink  30 . The pressing plates  531  of the pressing portion  53  resiliently press the two supporting plates  571  of the two supporting portions  57 , respectively. The joining plate  533  of the pressing portion  53  is received in the recess  36  of the heat sink  30 . Opposite ends of the joining plate  533  are received in the grooves  5731  of the baffle plates  573  of the pressing portions  57 , respectively. In this state, the clip  50  and the heat sink  30  are assembled together. 
         [0021]    Then the heat sink  30  is pushed towards the PCB  10 , to make the fasteners  13  of the PCB  10  extend through the through holes  39  and the receiving spaces  38  of the heat sink  30  and the first through holes  5314  of the pressing plates  531  of the pressing portion  53  of the clip  50  in that order. In this state, each head  135  of the fastener  13  is locate above the engaging section  5313  of the corresponding pressing plate  531 , and the corresponding engaging portion  133  is received in the corresponding first through hole  5314 . The joining plate  533  of the pressing portion  53  is pushed by hand to slightly offset the pressing portion  53  in a direction perpendicular to the joining plate  533 . Thus, the engaging portions  133  of the fastener  13  enter the second through holes  5315  of the pressing plate  531 . The operating arm  583  is operated to make the front ends of the two rearmost third rods  555  spread frontward and downward, and make rear ends of the two rearmost third rods  555  spread rearward and upward. That is, the two rearmost third rods  555  are reoriented such that they are approximately level. The two rearmost third rods  555  thereby drive the two frontmost third rods  555 , which in turn drive the first and second rods  553 ,  554  to straighten upward to approximately upright orientations, in order to make the supporting portions  57  and the linking portions  54  move upward. 
         [0022]    Thus, a distance between each supporting plate  571  of the supporting portion  57  and the head  135  of the corresponding fastener  13  is shortened, and the engaging section  5313  of the corresponding pressing plate  531  of the pressing portion  53  is pressed by the head  135 . The engaging section  5313  is elastically deformed and resiliently presses the supporting portion  57 . When the point C of each operating portion  55  is located below the point A and the point B, the operating portions  55  are locked. Thereby, the heat sink assembly is completely assembled. In this state, the operating arm  583  of the handle  58  is horizontal and presses the linking portions  54 . The two third rods  555  of each operating portion  55  are approximately level and generally collinear with each other. 
         [0023]    It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.