Abstract:
A fixing auxiliary device includes a main body, at least an extension arm and an adhesive element. The main body has a first portion in contact with a connecting portion of a circuit board and a second portion coupled to an extension plate of a metallic assembly. The at least an extension arm extends from an edge of the main body and is bent toward one side of the main body so as to clamp the extension plate of the metallic assembly. The adhesive element is used for bonding the first portion of the main body onto the connecting portion of the circuit board.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a fixing auxiliary device, and more particularly to a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board.  
       BACKGROUND OF THE INVENTION  
       [0002]     With increasing integration of integrated circuits, electronic devices such as power adapters and power supply apparatuses are developed toward minimization. As the volume of the electronic device is decreased, the problem associated with heat dissipation becomes more serious. Take a power adapter for example. When the power adapter operates, the electronic components mounted on the printed circuit board thereof may generate energy in the form of heat, which is readily accumulated within the closed space and usually difficult to dissipate away. If the power adapter fails to transfer enough heat to ambient air, the elevated operating temperature may result in damage of the electronic components, a breakdown of the whole power adapter or reduced power conversion efficiency. In addition, when an electronic device is in the vicinity of an electromagnetic field in the radio frequency (RF) spectrum that is caused by another electronic component, EMI (electromagnetic interference) results in operational disruption of the electronic component. Problems with EMI and heat dissipation can be minimized by placing a metallic assembly such as an EMI shielding element or a heat sink on a surface of the circuit board.  
         [0003]     In order to attach and/or fix the metallic assembly onto the circuit board, the metallic assembly usually includes an extension plate inserting into corresponding insertion holes of the circuit board. After the extension plate is welded onto the circuit board by using a soldering material, the extension plate is fixed on the circuit board. Alternatively, the extension plate may be directly welded onto the circuit board. The metallic assembly is usually made of high thermally conductive material such as aluminum. As known, aluminum is not well bonded to the soldering material.  
         [0004]     In order to enhance fixing effect, a conventional fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board is illustrated with reference to  FIG. 1 . The metallic assembly  12  comprises an extension plate  120  with a perforation  121 . The circuit board  11  has therein an insertion hole  110 . The fixing auxiliary device  13  comprises a main body  130 , a screw  131  and a nut  132 . The main body  130  comprises another perforation  133  corresponding to the perforation  121  of the extension plate  120 . For fixing the metallic assembly  12 , the main body  130  is first combined with the metallic assembly  12  when the screw  131  penetrates through the perforations  133  and  121  and is screwed into the nut  132 , and then the bottom of the main body  130  is insert into the insertion hole  110 . Afterward, the main body  130  is welded onto the circuit board by using a soldering material.  
         [0005]     Since the fixing auxiliary device  13  comprises many components and the process for fixing the metallic assembly  12  onto the circuit board  11  is complicated, the use of the fixing auxiliary device  13  is not feasible. In addition, if the screw  131  is not tightly screwed into the nut  132 , the metallic assembly  12  would be pivotal about the fixing auxiliary device  13  and thus the metallic assembly is not securely attached onto the circuit board  11 .  
         [0006]     In views of the above-described disadvantages, the applicant keeps on carving unflaggingly to develop an improved fixing auxiliary device according to the present invention through wholehearted experience and research.  
       SUMMARY OF THE INVENTION  
       [0007]     An object of the present invention is to provide a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board, in which the fixing auxiliary device has a simple structure and the process for using the fixing auxiliary device is simplified.  
         [0008]     Another object of the present invention is to provide a fixing auxiliary device for facilitating a user to securely fix a metallic assembly onto a circuit board.  
         [0009]     In accordance with a first aspect of the present invention, there is provided a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board. The fixing auxiliary device comprises a main body, at least an extension arm and an adhesive element. The main body has a first portion in contact with a connecting portion of the circuit board and a second portion coupled to an extension plate of the metallic assembly. The at least an extension arm extends from an edge of the main body and is bent toward one side of the main body so as to clamp the extension plate of the metallic assembly. The adhesive element is used for bonding the first portion of the main body onto the connecting portion of the circuit board.  
         [0010]     Preferably, the metallic assembly is an EMI shielding element or a heat sink.  
         [0011]     In an embodiment, the connecting portion of the circuit board includes an insertion hole, and the first portion of the main body is a leg portion inserting into the insertion hole of the circuit board.  
         [0012]     In an embodiment, the insertion hole is a conductive via hole, and the leg portion is disposed at the bottom of the main body and integrally formed with the main body.  
         [0013]     In an embodiment, the connecting portion of the circuit board includes a contact pad, and the first portion of the main body is a bent portion perpendicular to the main body and parallel to a surface of the circuit board.  
         [0014]     In an embodiment, the connecting portion of the circuit board further includes a stub, and the first portion of the main body is a bent portion having a curved channel for partially accommodating the stub.  
         [0015]     In an embodiment, the second portion of the main body is a perforation corresponding to a protrusion part of the extension plate of the metallic assembly, and the protrusion part of the extension plate is embedded into the perforation of the main body.  
         [0016]     In an embodiment, the at least an extension arm comprises two extension arms extending from opposite edges of the main body and bent toward the same side of the main body so as to tightly clamp the extension plate of the metallic assembly.  
         [0017]     In an embodiment, the at least an extension arm is integrally formed with the main body.  
         [0018]     Preferably, the metallic assembly is made of aluminum, and the main body of the fixing auxiliary device is made of copper or tin.  
         [0019]     Preferably, the adhesive element is made of a soldering material.  
         [0020]     In accordance with a second aspect of the present invention, there is provided a packaging structure of a metallic assembly. The packaging structure comprises a circuit board, a metallic assembly and a fixing auxiliary device. The circuit board has at lease a connecting portion. The metallic assembly is mounted on a surface of the circuit board and having at least an extension plate. The fixing auxiliary device comprises a main body, at least an extension arm and an adhesive element. The main body has a first portion in contact with a connecting portion of the circuit board and a second portion coupled to an extension plate of the metallic assembly. The at least an extension arm extends from an edge of the main body and is bent toward one side of the main body so as to clamp the extension plate of the metallic assembly. The adhesive element is used for bonding the first portion of the main body onto the connecting portion of the circuit board.  
         [0021]     The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]      FIG. 1  illustrates a conventional fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board;  
         [0023]      FIG. 2  illustrates a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board according to a preferred embodiment of the present invention;  
         [0024]     FIGS.  3 ( a ) and  3 ( b ) illustrate formation of the extension arms shown in  FIG. 2 ;  
         [0025]      FIG. 4  illustrates the fixing auxiliary device of  FIG. 2  welded onto the circuit board;  
         [0026]      FIG. 5  illustrates a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board according to another preferred embodiment of the present invention;  
         [0027]     FIGS.  6 ( a ) and  6 ( b ) illustrate formation of the extension arms shown in  FIG. 5 ;  
         [0028]      FIG. 7  illustrates the fixing auxiliary device of  FIG. 5  welded onto the circuit board; and  
         [0029]      FIG. 8  illustrates a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board according to a further preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]     The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.  
         [0031]     Referring to  FIG. 2 , a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board according to a preferred embodiment of the present invention is illustrated. The circuit board  21  has therein one or more connecting portions such as an insertion hole  210 . In an embodiment, the insertion hole  210  is arranged on the rear side of the circuit board  21 . The metallic assembly  22  is disposed on the front side and/or rear side of the circuit board  21 , and comprises an extension plate  220 . A fixing auxiliary device  23  for fixing the metallic assembly  22  onto the circuit board  21  comprises a main body  230 , two extension arms  231  and  232 , and an adhesive element (not shown). The bottom of the main body  230  defines a leg potion  234 . Firstly, the fixing auxiliary device  23  is coupled to the extension plate  220  of the metallic assembly  22 . Then, the leg potion  234  is inserted into the insertion hole  210 . Afterward, the leg potion  234  of the fixing auxiliary device  23  is welded onto the circuit board  21  by using the adhesive element (not shown). In such a manner, the fixing auxiliary device  23  is capable of facilitating secure attachment of the metallic assembly  22  onto the circuit board  21  and/or electrical connection between the metallic assembly  22  and the circuit board  21 , thereby forming the packaging structure  2 .  
         [0032]     Please refer to FIGS.  3 ( a ) and  3 ( b ), which illustrate formation of the extension arms  231  and  232 . Originally, the extension arms  231  and  232  are located at opposite edges of the main body  230 , as shown in  FIG. 3 ( a ). After the extension arms  231  and  232  are bent toward the same side, an elongated slot  236  is defined between the extension arms  231  and  232  and the main body  230 , as shown in  FIG. 3 ( b ). The width of the elongated slot  236  is substantially identical to that of the extension plate  220  of the metallic assembly  22 , thereby accommodating the extension plate  220  therein.  
         [0033]     Referring to  2  and  3 , the main body  230  further comprises a perforation  235  corresponding to a protrusion part  221  of the extension plate  220 . After the protrusion part  221  of the extension plate  220  is embedded into the perforation  235  of the main body  230 , the extension arms  231  and  232  may clamp the extension plate  220  tightly when a clamping tool is used to clamp the external surfaces of the extension arms  231  and  232 . The leg potion  234  is inserted into the insertion hole  210 . Afterward, the fixing auxiliary device  23  is welded onto the circuit board  21  by using an adhesive element  237 , as shown in  FIG. 4 .  
         [0034]     Referring to  FIG. 5 , a further embodiment of a fixing auxiliary device for facilitating a user to fix a metallic assembly onto a circuit board according to a preferred embodiment of the present invention is illustrated. The circuit board  21  has thereon one or more connecting portions such as a contact pad  211 . The metallic assembly  22  is disposed on the front side and/or rear side of the circuit board  21 , and comprises an extension plate  220 . A fixing auxiliary devices  23  for fixing the metallic assembly  22  onto the circuit board  21  comprises a main body  230 , two extension arms  231  and  232 , and an adhesive element (not shown). The bottom of the main body  230  defines a bent potion  238 , which is perpendicular to the main body  230  and parallel to the surface of the circuit board  21 . Firstly, the fixing auxiliary device  23  is coupled to corresponding extension plate  220  of the metallic assembly  22 . Then, the bent potion  238  is in contact with the contact pad  211 . Afterward, the bent potion  238  of the fixing auxiliary device  23  is welded onto the circuit board  21  by using the adhesive element (not shown). In such a manner, the fixing auxiliary device  23  is capable of facilitating secure attachment of the metallic assembly  22  onto the circuit board  21  and/or electrical connection between the metallic assembly  22  and the circuit board  21 , thereby forming the packaging structure  2 .  
         [0035]     Please refer to FIGS.  6 ( a ) and  6 ( b ), which illustrate formation of the extension arms  231  and  232 . Originally, the extension arms  231  and  232  are located at opposite edges of the main body  230 , as shown in  FIG. 6 ( a ). After the extension arms  231  and  232  are bent toward the same side, an elongated slot  236  is defined between the extension arms  231  and  232  and the main body  230 , as shown in  FIG. 3 ( b ). The width of the elongated slot  236  is substantially identical to that of the extension plate  220  of the metallic assembly  22 , thereby accommodating the extension plate  220  therein. The bent potion  238  is created by bending the bottom of the main body  230  such that the bent portion  238  is perpendicular to the main body  230  and parallel to the surface of the circuit board  21 .  
         [0036]     Referring to  5  and  6 , the main body  230  further comprises a perforation  235  corresponding to a protrusion part  221  of the extension plate  220 . The protrusion part  221  of the extension plate  220  is embedded into the perforation  235  of the main body  230 . After the protrusion part  221  of the extension plate  220  is embedded into the perforation  235  of the main body  230 , the extension arms  231  and  232  may clamp the extension plate  220  tightly when a clamping tool is used to clamp the external surfaces of the extension arms  231  and  232 . The bent potion  238  is then placed on the contact pad  211 . Afterward, the bent potion  238  of the fixing auxiliary device  23  is welded onto the circuit board  21  by using the adhesive element  237 , as shown in  FIG. 7 .  
         [0037]     In the above embodiments, the metallic assembly  22  used in the present invention may be an EMI shielding element or a heat sink. The insertion hole  210  can be a conductive via hole such as a ground via. In a case that the metallic assembly  22  is an EMI shielding element, the problem of EMI disruption would be minimized. In another case that the metallic assembly  22  is a heat sink, heat dissipation efficiency of the electronic device mounted on the circuit board  21  would be increased. Preferably, the extension arms  231  and  232  and the main body  230  are integrally formed. In addition, it is preferred that the leg potion  234  and the main body  230  are integrally formed. In some embodiments, the metallic assembly  22  is made of aluminum, and the main body  230  of the fixing auxiliary device  23  is made of copper or tin. An exemplary adhesive element  237  is a soldering material.  
         [0038]     Alternatively, as shown in  FIG. 8 , the connecting portion of the circuit board  21  further comprises a stub  212 , and the bent potion  238  of the fixing auxiliary device  23  further comprises a curved channel  239  for partially accommodating the stub  212 . Since the stub  212  is welded onto the circuit board  21  and bonded to the curved channel  239  by using the adhesive element  237 , more secure attachment of the metallic assembly  22  onto the circuit board  21  and/or electrical connection between the metallic assembly  22  and the circuit board  21  is achieved.  
         [0039]     From the above description, the fixing auxiliary device of the present invention is capable of facilitating a user to fix a metallic assembly onto a circuit board. In addition, since the fixing auxiliary device has a simple structure and the process for using the fixing auxiliary device is simplified, the process for packaging the metallic assembly on the circuit board is also simplified.  
         [0040]     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.