Abstract:
A spring sheet assembly for electrically connecting a printed circuit board to ground includes a base and a conductive spring sheet. The conductive spring sheet includes a fixing portion and a resisting portion. The base defines a latching slot for detachably receiving the fixing portion of the spring sheet.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to spring sheet assemblies. 
         [0003]    2. Description of Related Art 
         [0004]    Conventional methods for preventing electromagnetic interference (EMI) from leaking from digital electronic products generally use a spring sheet for electrically conducting EMI sources to the ground to eliminate the EMI. The spring sheet is fixed on the PCB of the electronic product by surface mounting technology (SMT). However, because different electronic products have various sizes, it is impossible for the SMT machine to suck all various spring sheets having high heights and/or complex shapes. In addition, it is also difficult to disassemble the spring sheet from the PCB while reworking the PCB, which wastes time and weakens the stability of the PCB. 
         [0005]    Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is an exploded, isometric perspective view of a spring sheet assembly in accordance with an exemplary embodiment of the disclosure, the spring sheet assembly comprising a spring sheet and a base. 
           [0007]      FIG. 2  is an assembled view of the spring sheet assembly of  FIG. 1 . 
           [0008]      FIG. 3  is an isometric perspective view of the base of  FIG. 1 . 
           [0009]      FIG. 4  is an isometric perspective view of a base in accordance with another exemplary embodiment of the disclosure. 
           [0010]      FIG. 5  is an assembled view of the spring sheet assembly of  FIG. 1  assembled between a PCB and a metal cage. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0011]    Referring to  FIG. 1 , a spring sheet assembly  10  according to an exemplary embodiment of the present disclosure comprises a base  20  and a conductive spring sheet  30  selected from a plurality of conductive spring sheets  30  having different heights (only one conductive spring sheet  30  is illustrated in  FIG. 1  for simplicity). Each of selected one of the conductive spring sheets  30  is adaptable to be assembled to the base  20  and comprises a fixing portion  301  and a resisting portion  304 . The resisting portions  304  of different conductive spring sheets  30  have different heights when not subjected to an external force. The fixing portion  301  comprises a bottom  3011  and at least one side wall extending from at least one end of the bottom  3011 . In this exemplary embodiment, there are two opposite side walls  3012 ,  3013  respectively extending from two opposite ends of the bottom  3011 , and which collectively define a surrounding space  302 . In this exemplary embodiment, the spring sheet  30  further comprises an elastic portion  303  connected between the fixing portion  301  and the resisting portion  304 , and forming substantially an “S” shape with the resisting portion  304 . In other embodiments, the elastic portion  303  can form substantially a “Z” shape. 
         [0012]    The base  20  comprises a base bottom  201  and a pair of bent portions  202  located at opposite edges of the base bottom  201 , wherein the pair of bent portions  202  and the base bottom  201  collectively define a latching slot  204 . Each bent portion  202  comprises a latching portion  2021  and a wing portion  2022 . The two latching portions  2021  of the pair of bent portions  202  respectively extend from the opposite edges of the base bottom  201  and towards to each other, thus form the latching slot  204 . The wing portions  2022  of the pair of bent portions  202  further extend from the latching portions  2021  respectively and form substantially a “V” shape for conveniently receiving the fixing portion  301  into the latching slot  204  and releasing the fixing portion  301  when applying an external force on the wing portions  2022 . 
         [0013]      FIG. 2  shows an assembled view of the spring sheet assembly  10  of  FIG. 1 . When installing the spring sheet  30  into the base  20 , the fixing portion  301  can be pushed into the latching slot  204  under an external force along the “V” shape formed by the wing portions  2022 . Advantageously, another external force F can be put upon the two wing portions  2022 , as illustrated in  FIG. 3 , thus the bent portions  202  move away from each other and provide a larger distance D 2  than when there is no external force F. As a result, the bottom  3011  of the fixing portion  301  can be easily fixed into the latching slot  204  of the base  20 . After removal of the external force F, the spring sheet  30  is firmly fixed to the base  20 . To release the spring sheet  30  from the base  20 , an external force F is applied to the two wing portions  2022 , causing the bent portions  202  to move away from each other and provide a larger distance D 2  than when there is no external force F. The fixing portion  301  is then taken out from the latching slot  204  and the spring sheet  30  disassembled from the base  20 . 
         [0014]    Referring to  FIG. 3 , an isometric perspective view of the base  20  of  FIG. 1  is shown. The base bottom  201  is flat, and the base  20  is mounted on the PCB by surface mounting technology (SMT) process. It is easy for a SMT machine to suck the base  20  because of its low height and simple shape, and the base  20  also has good performance of sucking tin thereon. 
         [0015]    Referring  FIG. 4 , it shows an isometric perspective view of a base  20 ′ in accordance with another exemplary embodiment of the present disclosure. The difference between the base  20 ′ and the base  20  of  FIG. 3  is in that the base  20 ′ comprises at least one pin extending vertically from the base bottom  201 ′ and inserted into at least one via defined in the PCB to reliably connect the base  20 ′ to the PCB. In this exemplary embodiment, the base  20 ′ comprises two pins  42 ,  43  inserted in two vias defined in the PCB to connect the base  20 ′ to the PCB reliably. 
         [0016]    Referring  FIG. 2  and  FIG. 5  simultaneously,  FIG. 5  shows an assembled view of the spring sheet assembly  10  of  FIG. 1  assembled between a PCB  50  and a metal cage  60 . The spring sheet assembly  10  is located between the PCB  50  and an inner surface of the metal cage  60  to electrically connecting the PCB  50  to the metal cage  60  to reliably ground the PCB  50 . The base  20  is mounted on the PCB  50  by SMT process, the fixing portion  301  of the spring sheet  30  is latched into the latching slot  204 , and the resisting portion  304  of the spring sheet  30  abuts against the inner surface of the metal cage  60  under the elasticity of the elastic portion  303  of the spring sheet  30 , which form a reliable ground path. When replacing the current spring sheet  30  with a different spring sheet having a different height, the bent portions  202  are pushed under the external force to release the current spring sheet  30  from the base  20 , and another spring sheet is assembled to the base  20 , by the method as description above. The whole process of changing the spring sheet  30  is convenient and efficient. 
         [0017]    Compared with conventional spring sheets, the spring sheet assembly of this disclosure has the following advantages. Firstly, in the SMT process, it is easy for the SMT machine to suck the base  20  of the spring sheet assembly  10  and the base  20  has a good performance of absorbing tin due to low height and simple shape thereof. Secondly, it is convenient to replace the current spring sheet with another spring sheet having different height from that of the current spring sheet without changing the design of the PCB and the metal cage, because the spring sheet can be easily disassembled from the PCB by pressing the wing portions of the base  20 . As a result, the productivity and the stability of the PCB are improved. 
         [0018]    While exemplary embodiments have been described, it should be understood that they have been presented by way of example only and not by way of limitation. The breadth and scope of the disclosure should not be limited by the described exemplary embodiments, but only in accordance with the following claims and their equivalents.