Patent Publication Number: US-2013235528-A1

Title: Assembled electromagnetic shielding case

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s).101108099 filed in Taiwan, R.O.C. on Mar. 9, 2012, the entire contents of which are hereby incorporated by reference. 
     FIELD OF TECHNOLOGY 
     The present invention relates to assembled electromagnetic shielding cases, and more particularly, to an assembled electromagnetic shielding case that is easy to install and uninstall. 
     BACKGROUND 
     Referring to  FIG. 1 , according to the prior art, to protect an electronic device  2  against electromagnetic interference (EMI) and the EMI-induced deterioration of the performance of the electronic device  2 , a typical protective measures taken involves soldering a shielding housing  8  to a printed circuit board  4  inside the electronic device  2  to cover a related electronic component  6  mounted on the printed circuit board  4  and coupling a plurality of pins  82  of the shielding housing  8  to a plurality of through holes  42  of the printed circuit board  4 , respectively, so as to form a shielding case for fending off the electromagnetic interference 
     However, if the electronic component  6  of the printed circuit board  4  breaks down and needs to be replaced, it will be necessary to unsolder the shielding housing  8  and the printed circuit board  4  in order to carry out the replacement. In general, after being unsoldered, the shielding housing  8  becomes unusable, thereby reducing ease of use and incurring costs. 
     Furthermore, when covered with the shielding housing  8 , the electronic component  6  in operation generates heat that cannot be efficiently dissipated. To enhance heat dissipation, the prior art teaches filling the space defined between the electronic component  6  and the shielding housing  8  with a thermal pad and applying a thermal paste to the shielding housing  8  for enhancing heat dissipation. In practice, the aforesaid attempt to enhance heat dissipation fails. Heat dissipation efficiency decreases, because a bulky heat dissipation structure is formed from the electronic component  6  and plenty of intermediates (such as the thermal pad, the shielding housing  8 , the thermal paste, and a heat sink.) 
     Accordingly, the present invention provides an assembled electromagnetic shielding case whereby an electronic component of an electronic device is not only protected against electromagnetic interference but also replaced conveniently, so as to carry out heat dissipation efficiently and provide a miniaturized heat dissipation structure. 
     SUMMARY 
     It is an objective of the present invention to provide an assembled electromagnetic shielding case for protecting an electronic device against electromagnetic interference and changing an electronic component conveniently. 
     Another objective of the present invention is to provide an assembled electromagnetic shielding case for effectuating a miniaturized heat dissipation structure and enhancing heat dissipation efficiency. 
     In order to achieve the above and other objectives, the present invention provides an assembled electromagnetic shielding case conducive to electromagnetic interference shielding and heat dissipation of an electronic component on a printed circuit board. The assembled electromagnetic shielding case comprises a body, a shielding element, and a fixing element. The body has an opening and an engagement portion. The engagement portion connects the body and the printed circuit board. The shielding element closes the opening to provide electromagnetic shielding and has a bottom side and a heat-dissipating side opposing to the bottom side. The shielding element dissipates heat generated from the electronic component by transferring the heat from the bottom side to the heat-dissipating side for dissipating the heat. The fixing element couples the body and the shielding element together. 
     Compared with the prior art, the present invention provides an assembled electromagnetic shielding case essentially comprising a body and a shielding element coupled thereto, such that an electronic component can be covered with the assembled electromagnetic shielding case to fend off electromagnetic interference, facilitate replacement of the electronic component, effectuate heat dissipation efficiently, and provide a miniaturized heat dissipation structure. 
     BRIEF DESCRIPTION 
     Objectives, features, and advantages of the present invention are hereunder illustrated with specific embodiments in conjunction with the accompanying drawings, in which: 
       FIG. 1  (PRIOR ART) is a structural schematic view of a conventional shielding housing; 
       FIG. 2  is a schematic view of an assembled electromagnetic shielding case according to the first embodiment of the present invention; 
       FIG. 3  is another schematic view of the assembled electromagnetic shielding case according to the first embodiment of the present invention; 
       FIG. 4  is yet another schematic view of the assembled electromagnetic shielding case according to the first embodiment of the present invention; 
       FIG. 5  is a schematic view of an assembled electromagnetic shielding case according to the second embodiment of the present invention; 
       FIG. 6  is another schematic view of the assembled electromagnetic shielding case according to the second embodiment of the present invention; 
       FIG. 7  is a schematic view of an assembled electromagnetic shielding case according to the third embodiment of the present invention; 
       FIG. 8  is another schematic view of the assembled electromagnetic shielding case according to the third embodiment of the present invention; and 
       FIG. 9  is a cross-sectional view of an assembled electromagnetic shielding case according to the fourth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 2 , there is shown a schematic view of an assembled electromagnetic shielding case  10  according to the first embodiment of the present invention. As shown in  FIG. 2 , the assembled electromagnetic shielding case  10  enables electromagnetic interference shielding and heat dissipation to occur to an electronic component  6  mounted on a printed circuit board  4  as shown in  FIG. 9 . 
     The assembled electromagnetic shielding case  10  comprises a body  12 , a shielding element  14 , and a fixing element  16 . The purpose of the fixing element  16  is to couple the body  12  and the shielding element  14  together. 
     The body  12  has an opening  122  and an engagement portion  124 . The opening  122  is designed to be closed with the shielding element  14 . In the first embodiment, the opening  122  is formed on top of the body  12 . For example, the opening  122  is formed, by hollowing out the body  12 . Alternatively, the body  12  and the opening  122  are integrally formed as a unitary structure. The purpose of the engagement portion  124  is to connect the body  12  and the printed circuit board  4 . For example, the engagement portion  124  come in the form of a pin or a means of surface mounted devices (SMD), for fixing the body  12  to the printed circuit board  4  in a removable manner or a fixed manner. The first embodiment is exemplified by the pin-shaped engagement portion  124 , wherein the pin-shaped engagement portion  124  is disposed at the edge of the body  12  and protrudes from the body  12 . Furthermore, the first embodiment and  FIG. 2  are not restrictive of the shape, quantity, and position of the opening  122 . In practice, the assembled electromagnetic shielding case  10  of the present invention can have two said openings  122  corresponding in position to two said electronic components  6 , respectively. Alternatively, in practice, the opening  122  of the assembled electromagnetic shielding case  10  of the present invention is trapezoidal. 
     The shielding element  14  has a bottom side  144  and a heat-dissipating side  142  opposing to the bottom side  144 . The shielding element  14  is disposed on a surface of the body  12 , coupled thereto, and positioned at the opening  122  in a manner that the shielding element  14  closes the opening  122  to provide electromagnetic interference shielding, thereby protecting the electronic component  6  against electromagnetic interference. The shielding element  14  dissipates heat generated from the electronic component  6  by transferring the heat from the bottom side  144  to the heat-dissipating side  142  for dissipating the heat. In an embodiment, the area of the bottom side  144  is larger than or equal to the area of the opening  122 . Hence, with the shielding element  14  being capable of closing the opening  122 , the shielding element  14  provides electromagnetic interference shielding to the electronic component  6  as soon as the shielding element  14  is coupled to the body  12 . 
     The fixing element  16  serves to couple the body  12  and the shielding element  14  together. For example, the fixing element  16  comprises and a snap-engagement structure, a track structure, and/or a magnetic suction structure. In the first embodiment, the fixing element  16  is exemplified by a snap-engagement structure. Furthermore, in a variant embodiment associated with the first embodiment, the fixing element is disposed at the body  12  or the shielding element  14 , or, alternatively, the fixing element is disposed at the body  12  and the shielding element  14 . Furthermore, in the first embodiment, the snap-engagement structure, that is, the fixing element  16 , comprises a resilient engaging plate  162  and an engaging hook  164 . Referring to  FIG. 3 , the engaging hook  164  is snap-engaged with one edge of the shielding element  14 , whereas the resilient engaging plate  162  causes the shielding element  14  to abut against the engaging hook  164 , such that the shielding element  14  is fixed to the body  12 , thereby preventing the shielding element  14  from moving relative to the body  12 . 
     In case the electronic component  6  mounted on the printed circuit board  4  has to be uninstalled, the user can exert a force upon the resilient engaging plate  162  to cause resilient deformation to the resilient engaging plate  162 . As a result, the shielding element  14  separates from the body  12 , and then the user can uninstall the electronic component  6  by hand through the opening  122 . 
     Furthermore, any heat generated from the electronic component  6  can be dissipated through the heat-dissipating side  142 . Referring to  FIG. 4 , the assembled electromagnetic shielding case  10  further comprises a heat sink  146  disposed on the heat-dissipating side  142  of the shielding element  14  for enhancing the heat dissipation function of the heat-dissipating side  142 . For example, the heat sink  146  is a fin heat sink or a plate heat sink. Hence, the shielding element  14  serves to dissipate heat in the same way as a heat sink does. Furthermore, to position the shielding element  14  at the body  12 , the user can position the shielding element  14  above the electronic component  6  mounted on the printed circuit board  4 , such that heat generated from the electronic component  6  can be dissipated through the shielding element  14  to thereby lower the temperature of the body  12  and the electronic component  6 . 
     Referring to  FIG. 5 , there is shown a schematic view of an assembled electromagnetic shielding case  10 ′ according to the second embodiment of the present invention. As shown in  FIG. 5 , the assembled electromagnetic shielding case  10 ′ enables electromagnetic interference shielding and heat dissipation to occur to the electronic component  6  mounted on the printed circuit board  4 . In the second embodiment, the assembled electromagnetic shielding case  10 ′ comprises the body  12 , the shielding element  14 , the fixing element  16 , and a stopping member  18 . The stopping member  18  distinguishes the second embodiment from the first embodiment and is disposed at the periphery of the opening  122  for stopping and positioning the shielding element  14  at the opening  122 , such that the shielding element  14  can completely hide the opening  122 . Precisely speaking, the shielding element  14  is confined to the body  12  by means of the stopping member  18  and thereby prevented from sliding, such that the shielding element  14  can be firmly fixed to the body  12  as shown in  FIG. 6 . 
     In the second embodiment, the fixing element  16  comprises a resilient engaging plate  162 ′ having a flange and the engaging hook  164 . Referring to  FIG. 6 , the engaging hook  164  is snap-engaged with one edge of the shielding element  14 , whereas the resilient engaging plate  162 ′ causes the engaging hook  164  to abut against the shielding element  14 . Furthermore, the flange of the resilient engaging plate  162 ′ is snap-engaged with the other edge of the shielding element  14 , such that the shielding element  14  is fixed to the body  12  and prevented from moving relative to the body  12 . 
     Referring to  FIG. 7 , there is shown a schematic view of an assembled electromagnetic shielding case  10 ″ according to the third embodiment of the present invention. As shown in  FIG. 7 , the assembled electromagnetic shielding case  10 ″ enables electromagnetic interference shielding and heat dissipation to occur to the electronic component  6  mounted on the printed circuit board  4 . In the third embodiment, the assembled electromagnetic shielding case  10 ″ comprises the body  12 , the shielding element  14 , and a fixing element  16 ′. The fixing element  16 ′, which distinguishes the third embodiment from the first and second embodiments, is disposed at both the shielding element  14  and the body  12 . The fixing element  16 ′ couples the shielding element  14  and the body  12  together. In the third embodiment, the fixing element  16 ′ at the body  12  comprises a T-shaped engaging hook  166  and the resilient engaging plate  162 , whereas the fixing element  16 ′ at the shielding element  14  is implemented in the form of a notch  168 . The T-shaped engaging hook  166  corresponds in position to the notch  168  and enables the shielding element  14  to be snap-engaged with the body  12  as shown in  FIG. 8 . 
     Referring to  FIG. 9 , there is shown a cross-sectional view of an assembled electromagnetic shielding case  10 ″′ according to the fourth embodiment of the present invention. As shown in  FIG. 9 , the assembled electromagnetic shielding case  10 ″′ enables electromagnetic interference shielding and heat dissipation to occur to the electronic component  6  mounted on the printed circuit board  4 . In the fourth embodiment, the assembled electromagnetic shielding case  10 ″′ comprises the body  12 , the shielding element  14 , the fixing element  16 , the stopping member  18 , and a thermal conductor  22 . The thermal conductor  22 , which distinguishes the fourth embodiment from the preceding embodiments, is disposed on the bottom side  144  of the shielding element  14  and intended to be positioned between the shielding element  14  and the electronic component  6 . For example, the thermal conductor  22  is a thermal pad or a thermal paste. After coming into contact with both the bottom side  144  and the electronic component  6  simultaneously, the thermal conductor  22  transfers heat generated by the electronic component  6  to the shielding element  14 , thereby enhancing the heat transfer between the shielding element  14  and the electronic component  6  so as to speed up heat dissipation of the electronic component  6 . 
     Compared with the prior art, the present invention provides an assembled electromagnetic shielding case characterized by a coupling of a body and a shielding element, so as to protect an electronic device against electromagnetic interference, facilitate replacement of an electronic component, achieve highly efficient heat dissipation, and provide a miniaturized heat dissipation structure. 
     The present invention is disclosed above by preferred embodiments. However, persons skilled in the art should understand that the preferred embodiments are illustrative of the present invention only, but should not be interpreted as restrictive of the scope of the present invention. Hence, all equivalent modifications and replacements made to the aforesaid embodiments should fall within the scope of the present invention. Accordingly, the legal protection for the present invention should be defined by the appended claims.