Patent Publication Number: US-2019174618-A1

Title: Printed Circuit Assembly with Vents and Electronic Device with the Assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of Taiwan Patent Application No. 106218043, filed on Dec. 5, 2017, in the Taiwan Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a printed circuit assembly and an electronic device equipped with the printed circuit assembly, and more particularly to the printed circuit assembly or the electronic device with thermal vents. 
     2. Description of the Related Art 
     It is well known that a printed circuit assembly, such as motherboard or expansion card, may be equipped with one or more M.2 connectors. The M.2 connectors are provided for connection with a M.2 expansion card, such as M.2 solid-state drive card (M.2 SSD card). As shown in  FIG. 8 , there is shown a SSD card  2  assembled to a motherboard  1  via a M.2 connector  10  and a threaded standoff  11 . Specifically, the M.2 connector  10  and the standoff  11  are both mounted on the mother board  1  and spaced apart in distance. The SSD card  2  has one end engaged with the M.2 connector  10 , and the other end held by the standoff  11  and a bolt  3 . In addition, on the top and bottom surfaces  21 ,  22  of the SSD card  2  are a plurality of chips  23 , such as NAND flash memory chips or controller chips. Furthermore, a heat sink  4  is provided on top of the chips  23  for heat removal from the chips  23 . 
     However, as can be seen in  FIG. 8 , since the space G between the SSD card  2  and the motherboard  1  is quiet small and tight, the heat sink  4  can only be arranged on the upper chips  23  on the top surface  21  of the SSD card  2 . As such, heat generated by the upper chips  23  can be easily removed, but the heat generated by the lower chips  23  on the bottom surface  22  of the SSD card  2  can hardly be dissipated and thus adversely affect the performance of the SSD card  2 . 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved printed circuit assembly to solve the problems mentioned above. 
     Briefly described, the printed circuit assembly generally includes a printed wiring board and an expansion connector. The printed wiring board has a top surface, a bottom surface, a specific area defined at the top surface thereof for placement of an expansion card, and at least one thermal vent defined in the specific area and extending from the top surface to the bottom surface of the printed wiring board. The expansion connector, such as a M.2 connector, is disposed on the printed wiring board and is located in the specific area for connection with one side edge of the expansion card. 
     Preferred embodiments of the invention may have the following additional characteristics, either alone or in combination: 
     The thermal vent represents a letter, a numeral, a symbol or a graphic design in shape. 
     The printed circuit assembly further includes a fastener disposed in the specific area on the printed wiring board for securing the other side edge of the expansion card. 
     The fastener includes a threaded standoff and a bolt. The threaded standoff is engaged in a screw hole defined in the printed wiring board for supporting the other side edge of the expansion card. The bolt is engaged in a screw hole of the threaded standoff for securing the other side edge of the expansion card onto the threaded standoff. 
     The present invention further provides an electronic device with the aforementioned printed circuit assembly. The printed circuit assembly generally includes a printed wiring board and an expansion connector. 
     Preferably, the electronic device further includes a metal plate on which the printed wiring board is mounted. 
     Preferably, the metal plate defines at least one through hole corresponding to the at least one thermal vent of the printed wiring board. 
     The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a printed circuit assembly as well as an expansion card in accordance with one embodiment of the present invention; 
         FIG. 2  is a partial top view of the printed circuit assembly shown in  FIG. 1 ; 
         FIG. 3  is a partial side view of the printed circuit assembly and the expansion card shown in  FIG. 1 ; 
         FIG. 4  is a perspective view of a printed circuit assembly as well as an expansion card in accordance with another embodiment of the present invention; 
         FIGS. 5 a -5 d    illustrate a variety of printed circuit assemblies with different shapes of thermal vents; 
         FIG. 6  is a side view of an electronic device in accordance with one embodiment of the present invention; 
         FIG. 7  is a side view of an electronic device in accordance with another embodiment of the present invention; and 
         FIG. 8  is a prior art. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Referring to  FIGS. 1 and 2 , there is shown one embodiment of a printed circuit assembly  5  on which an expansion card  6  is to be mounted. In this embodiment, the printed circuit assembly  5  is directed to a computer motherboard. However, in other examples, the printed circuit assembly  5  may be a PCIe expansion card, as shown in  FIG. 5 , or other cards. Briefly, the printed circuit assembly  5  includes a printed wiring board  50  and an expansion connector  51 . 
     The printed wiring board  50  has a top surface  501 , a bottom surface  502 , a specific area  504  defined at the top surface  501  thereof for placement of the expansion card  6 , and one or more thermal vents  503  defined in the specific area  504 . Note that each of the thermal vents  503  extends from the top surface to the bottom surface of the printed wiring board  50 . 
     The expansion connector  51  is disposed on the printed wiring board  50  and located in the specific area  504  for connection with one side edge  60  of the expansion card  6 , as depicted in  FIG. 3 . In this embodiment, the expansion connector  51  is directed to a M.2 connector, and the expansion card  6  is directed to a M.2 SSD card. On top and bottom surfaces  62 ,  63  of the expand card  6  are equipped with a plurality of chips  64 , such as NAND flash memory chips or controller chips. In addition, a heat sink  65  is arranged on the upper chips  64  on the top surface  62  of the expansion card  6  for heat dissipation. 
     As shown in  FIGS. 1 and 3 , the printed circuit assembly  5  may further includes a fastener  52  disposed in the specific area  504  on the printed wiring board  50  for securing the other side edge  61  of the expansion card  6 . More specifically, the printed wiring board  50  is provided with a row of mounting bases  505  each defining a screw hole  505   a  therein. According to the length of the expansion card  6 , the fastener  52  may be selectively inserted in one of the threaded holes  505   a  of the mounting bases  505 . The fastener  52  includes a threaded standoff  521  and a bolt  522 . The standoff  521  is screwed in a selected one of the screw holes  505   a  of the mounting bases  505  for holding the other side edge  61  of the expansion card  6 . The bolt  522  is engaged in a screw hole  521   a  of the standoff  521  to secure the other side edge  61  of the expansion card  6  onto the standoff  521 . 
     It is noted that the amount of the thermal vents  503  may vary as needed. That is, one or more thermal vents  503  may be defined in the printed wiring board  50 . Besides, the positions of the thermal vents  503  may also be arranged as required. In this embodiment, there are two rows of thermal vents  503  arranged at opposite sides of the row of the mounting bases  505 , as shown in  FIG. 1 or 2 . 
     As shown in  FIG. 3 , there is a small space G 1  in between the bottom surface  63  of the expansion card  6  and the top surface  501  of the printed wiring board  50 . Though the space G 1  is small and tight, it is well ventilated because of the thermal vents  503  that are in communication with the space G 1 . As such, heat generated by the chips  64  underneath the expansion card  6  can still be well removed via the thermal vents  503 , ensuring that the expansion card  6  can function well without overheating problem. 
     Referring to  FIG. 4 , there is shown another embodiment of a printed circuit assembly  5  on which an expansion card  6  is to be mounted. In this embodiment, the printed circuit assembly  5  is directed to a PCIe expansion card through which the expansion card  6  (SSD card) can communicate with a motherboard for data transmission. 
     As shown in  FIGS. 5 a -5 d   , each of the thermal vents  503  may represent a letter, a numeral, a symbol or a graphic design in shape. As shown in  FIG. 5 a   , the set of thermal vents  503  may be arranged with symbol, letter and/or combination thereof. As shown in  FIG. 5 b   , the set of thermal vents  503  may be arranged with letter or numeral and/or combination thereof. As shown in  FIGS. 5 c  and 5 d   , each of the thermal vents  503  may be ellipse or rectangle in graphics, as desired. It is understood that other shapes may be applied for the thermal vents, too. 
     As shown in  FIG. 6 , there is shown one embodiment of an electronic device, which generally includes a printed wiring board  50 , an expansion connector  51 , an expansion card  6  and a threaded standoff  52 , as discussed earlier in the aforementioned embodiments, and also a metal plate  7 , as discussed further herein. The printed wiring board  50  is mounted on the metal plate  7  which serves a grounding electrode. In this embodiment, the metal plate  7  defines a plurality of through holes  70  respectively corresponding to the thermal vents  503  of the printed wiring board  50  for heat dissipation. The electronic device further includes a chassis  8 , and the metal plate  7  is mounted on a bottom plate  81  of the chassis  8 . Preferably, one or more holes  82  are defined in the bottom plate  81  of the chassis  8  corresponding to the through holes  70  in the metal plate  7  for heat dissipation. 
     As shown in  FIG. 7 , there is shown another embodiment of an electronic device. In this embodiment, the printed wiring board  50  is mounted on a metal plate  7   a  which serves a grounding electrode. Unlike the aforementioned metal plate  7  shown in  FIG. 6 , this metal plate  7   a  is substantially a part of a metallic chassis  700 . For instance, the metal plate  7   a  is a side plate or bottom plate of a computer chassis. Likewise, one or more through holes  70   a  may be defined in the metal plate  7   a  corresponding to the thermal vents  503  in the printed wiring board  50  for heat dissipation. 
     As described above, the printed circuit assembly  5  of the present invention is formed with one or more thermal vents  503  to assist heat dissipation for removing additional heat from the expansion card  6  (such as SSD card) on the printed wiring board  50 , thereby solving the overheating problems and improving the performance and functionality of chips  64  of the expansion card  6 .