Patent Publication Number: US-7214073-B2

Title: Shielding structure

Description:
INCORPORATION BY REFERENCE 
   The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2004-183487 filed on Jun. 22, 2004. The content of the application is incorporated herein by reference in its entirety. 
   BACKGROUND OF THE INVENTION 
   The present invention relates to a shield structure primarily for shielding high-frequency circuits and the like formed from multiple electronic components. 
   Conventionally, shielding electronic circuits such as high-frequency circuits formed from multiple electronic components attached to a substrate has been done by covering and surrounding the high-frequency circuit with a shield case formed as a box-shaped structure of conductive material. See, for example, Japanese Laid-Open Patent Publication Number Hei 06-338435. 
   However, in conventional technologies such as the one described above, the shield case must become larger if the number of electronic parts in the high-frequency circuit or the like increases, increasing the amount of space taken up on the substrate by these electronic parts. This makes it difficult to provide compact designs for devices. 
   OBJECT AND SUMMARY OF THE INVENTION 
   The object of the present invention is to overcome the problems of the conventional technology described above and to provide a shield structure that allows compact designs. 
   In order to overcome the problems described above, the present invention includes: a main substrate on which are mounted electronic components forming an electronic circuit. A secondary substrate is separated by a space from the main substrate and electronic components forming the electronic circuit are mounted on a surface of the secondary substrate that faces a mounting surface of the main substrate. Also, a shield perimeter wall is formed by a plurality of shielded substrate connectors connecting the main substrate and the secondary substrate. The plurality of shielded substrate connectors are disposed so as to surround the electronic circuit. The shielded substrate connector is formed from a plug mounted on either the primary or secondary substrate and a socket mounted on the other substrate and detachably connected to the plug. The plugs and the sockets are attached to the main substrate and the secondary substrate while being supported by an attachment tool member for supporting the plug or the socket in alignment with the shield perimeter wall. 
   In addition to the structure above, in the invention described an embodiment where the shielded substrate connector further includes a shield connection piece, formed from a conductive material, that connects shields of the shielded substrate connectors that are adjacent to each other along the perimeter. 
   In addition to the structures above, an embodiment of the plug include a synthetic resin plug housing and a plurality of plug contacts including plug elastic contact pieces exposed on a side surface of the plug housing. A plug shield member is formed from a conductive metal member that covers a side surface opposite from the side surface from which the plug elastic contact pieces are exposed. 
   The socket includes a socket housing formed with a plug insertion hole into which the plug is inserted a plurality of socket contacts including a socket elastic contact piece projecting into the plug insertion hole, and a socket shield member formed from a conductive metal member covering a side surface of the socket housing. 
   When the plug is inserted into the plug insertion hole, the plug elastic contact piece and the socket elastic contact piece form an elastic contact, and a contact is formed between the plug shield member and the socket shield member. 
   In addition to the structure above, the plug contact and the socket contact can include an attachment piece supported by the housing and a terminal continuous with one end of the attachment piece and pointing inward from the shield perimeter wall. The terminal is connected integrally with a carrier plate and a plurality of contacts are attached to the housing with the plurality of contacts supported integrally by the carrier plate, separated by spaces. 
   The shield structure a main substrate on which are mounted electronic components forming an electronic circuit, a secondary substrate separated by a space from the main substrate, electronic components forming the electronic circuit being mounted on a surface of the secondary substrate that face a mounting surface of the main substrate, and a shield perimeter wall formed by a plurality of shielded substrate connectors connecting the main substrate and the secondary substrate. The plurality of shielded substrate connectors can be disposed so as to surround the electronic circuit. Since the electronic parts forming the electronic circuit can be mounted on both the main and secondary substrates, the space taken up on the substrates by the electronic parts is reduced, thus allowing a compact design. 
   Also, the process for mounting the electronic components forming the electronic circuit can be divided into a step for the main substrate and the secondary substrate. This reduces the time required and can reduce production costs. 
   The shielded substrate connector can be formed from a plug mounted on either the primary or secondary substrate and a socket mounted on the other substrate and detachably connected to the plug. The plugs and the sockets can be attached to the main substrate and the secondary substrate while being supported by an attachment tool member for supporting the plug or the socket in alignment with the shield perimeter wall. As a result, the sockets and plugs can be mounted with a high degree of attachment precision, thus providing good connections. 
   The shielded substrate connector can further include a shield connection piece, formed from a conductive material, that connects shields of the shielded substrate connectors that are adjacent to each other along the perimeter. As a result, superior shielding can be provided. 
   The plug can include a synthetic resin plug housing, a plurality of plug contacts including plug elastic contact pieces exposed on a side surface of the plug housing, and a plug shield member formed from a conductive metal member that covers a side surface opposite from the side surface from which the plug elastic contact pieces are exposed. The socket can include a socket housing formed with a plug insertion hole into which the plug is inserted, a plurality of socket contacts including a socket elastic contact piece projecting into the plug insertion hole, and a socket shield member formed from a conductive metal member covering a side surface of the socket housing. When the plug is inserted into the plug insertion hole, the plug elastic contact piece and the socket elastic contact piece form an elastic contact, and a contact is formed between the plug shield member and the socket shield member. 
   The plug contact and the socket contact can include an attachment piece supported by the housing and a terminal continuous with one end of the attachment piece and pointing inward from the shield perimeter wall. The terminal is connected integrally with a carrier plate and a plurality of contacts are attached to the housing with the plurality of contacts supported integrally by the carrier plate, separated by spaces. Thus, the contacts can be efficiently attached to the housing and costs can be reduced. 
   The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-section drawing showing a shield structure according to the present invention; 
       FIG. 2  is a magnified cross-section detail drawing of the shield structure of  FIG. 1 ; 
       FIG. 3  is an example cross-sectional view showing the shielded substrate connector in a separated state of the present invention; 
       FIG. 4  is a plan drawing of a plug of the present invention; 
       FIG. 5  is a front-view drawing of the plug of  FIG. 4 ; 
       FIG. 6  is a bottom-view drawing of the plug of  FIG. 4 ; 
       FIG. 7  is a rear-view drawing of the plug of  FIG. 4 ; 
       FIG. 8  is a side-view drawing of the plug of  FIG. 4 ; 
       FIG. 9  is a cross-section drawing of the plug of  FIG. 4 ; 
       FIG. 10(   a ) is a plan drawing of a plug contact supported by a carrier plate of the present invention; 
       FIG. 10(   b ) is a front-view drawing of  FIG. 10(   a ); 
       FIG. 10(   c ) is a side-view drawing of  FIG. 10(   a ); 
       FIG. 11(   a ) is a plan drawing showing a plug attachment tool member of the present invention; 
       FIG. 11(   b ) is a cross-section drawing of the plug attachment tool member of  FIG. 11(   a ); 
       FIG. 12  is a cross-section detail drawing showing a plug attachment step; 
       FIG. 13  is a plan drawing showing a secondary substrate assembly of the present invention; 
       FIG. 14  is a plan drawing showing the socket of  FIG. 1 ; 
       FIG. 15  is a front-view drawing of the socket of  FIG. 1 ; 
       FIG. 16  is a bottom-view drawing of the socket of  FIG. 1 ; 
       FIG. 17  is a rear-view drawing of the socket of  FIG. 1 ; 
       FIG. 18  is a side-view drawing of the socket of  FIG. 1 ; 
       FIG. 19  is a cross-section drawing of the socket of  FIG. 1 ; 
       FIG. 20(   a ) is a plan drawing showing a socket contact supported by a carrier plate of the present invention; 
       FIG. 20(   b ) is a front-view drawing of  FIG. 20(   a ); 
       FIG. 20(   c ) is a side-view drawing of  FIG. 20(   a ); 
       FIG. 21(   a ) is a plan drawing of a socket attachment tool member embodiment of the present invention; 
       FIG. 21(   b ) is a cross-section drawing of  FIG. 21(   a ); 
       FIG. 22  is a cross-section detail drawing showing a socket attachment step of the present invention; and 
       FIG. 23  is a plan drawing showing a main substrate assembly of  FIG. 22 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A shield structure according to the present invention is shown in  FIG. 1  through  FIG. 3  and include a main substrate  2  on which electronic components  1  are mounted. A secondary substrate  3  can also accept electronic components  1  on the surface thereof facing a mounting surface of the main substrate  2 . A shield perimeter wall can include multiple shielded substrate connectors  4  connecting the main substrate  2  and the secondary substrate  3  are disposed to surround the electronic components  1 . The electronic circuit, e.g., a high-frequency circuit is formed by the electronic components  1  and mounted on the main substrate  1 . Further the secondary substrate  3  can be surrounded by the main substrate  2 . The secondary substrate  3  and the shield perimeter wall, i.e., the multiple shielded substrate connectors  4  can provide shielding for the electronic circuit. 
   The shielded substrate connector  4  is formed from a plug  5  mounted on the primary substrate  2  or the secondary substrate  3  and a socket  6  that can be attached to or removed from the plug  5 . 
   As shown in  FIG. 4  through  FIG. 9 , the plug  5  include a plug housing  7  multiple plug contacts  8  that can be supported by the plug housing  7  and a plug shield member  9  fitted to the outer perimeter surface of the plug housing  7 . 
   The plug housing  7  is formed in a rectangular shape with an insulative material such as synthetic resin and is formed integrally with a projection  7   a  disposed at the inside of the bottom end. 
   In this plug housing  7 , multiple contact attachment holes  10  can be formed parallel to each other at predetermined intervals. The attachment holes  10  pass through the housing  7  from top to bottom and are open at one side surface. More specifically, the attachment holes  10 ,  10  . . . open on the inner perimeter side of the shield perimeter wall. Pairs of securing ribs  11 ,  11  are formed integrally on the inner perimeter surfaces of the contact attachment holes  10 ,  10 . 
   A support cavity  12  into which the plug shield member  9  is fitted is formed on the outer perimeter side of the shield perimeter wall of the plug housing  7 . Engagement projections  13  are formed integrally on either side of the support cavity  12  to secure the plug shield member  9 . 
   As shown in  FIG. 10 , the plug contact  8  is inserted into the contact attachment hole  10  of the plug housing  7 . The plug contact  8  include an attachment piece  14  supported by the plug housing  7  a bend  15  formed as a “U”-shape from one end of the attachment piece  14  an elastic contact piece  16  continuous with the other end of the bend  15  and a terminal piece  17  bent from the other end of the attachment piece  14 . The plug contact  8  is formed by punching a conductive plate material such as a copper member into a predetermined shape and bending it. 
   The attachment piece  14  is formed as a thin plate having a width roughly the same as the width of the contact attachment hole  10 , and engagement projections  18  are formed integrally on the side edges. 
   The bend  15 , formed continuously with one end of the attachment piece  14 , has a width narrower than that of the attachment piece  14  and slightly narrower than the gap formed between the securing ribs  11  of the contact attachment hole  10 . 
   The elastic contact piece  16  can be formed as a thin plate continuous with the end of the bend  15  opposite from the attachment piece  14  with a width that is wider than that of the bend  15 . 
   The terminal  17  is continuous with the end of the attachment piece  14  opposite from the bend  15  and is bent to be roughly perpendicular to the attachment piece  14 , i.e., to point toward the inside of the shield perimeter wall when attached to the plug housing  7 . 
   The end of the terminal  17  opposite from the attachment piece  14  is integrally connected to a carrier plate  19 , and the multiple plug contacts  8  are supported parallel to each other on the carrier plate  19  at a predetermined pitch, i.e., the pitch at which the plug contacts  8  are attached to the plug housing  7 . 
   Terminal  17  and the carrier plate  19  can be formed with notches at the side edge of the connecting point so that once the plug contacts  8  are attached to the plug housing  7 , the terminal  17  and the carrier plate  19  can be easily separated. 
   The plug shield member  9  is formed integrally from a plate-shaped shield plate  20 , integrally formed side plates  21 ,  21  at the side edges of the shield plate  20 , and a securing piece  22  projecting outward from the bottom edge of the side plate  21 . The plug shield member  9  can be formed integrally by bending a conductive metal plate. 
   Engagement holes  23 ,  23  are formed at the side sections of the shield plate  20  to allow engagement of the engagement projection  13  formed at the outer perimeter surface of the plug housing  7 . The engagement of the engagement projection  13  with the engagement hole  23  secures the plug shield member  9  to the plug housing  7 . 
   The plugs  5  are mounted on the secondary substrate  3  using a plug attachment tool member  24  so that the electronic components  1  mounted on the secondary substrate  3  are surrounded. 
   As shown in  FIG. 11 , the plug attachment tool member  24  is formed as a frame equipped with supports  25  projected from the four edges on one surface. At the center of the frame is formed a circular suction section  27  supported from four sides via supports  26 , and this suction section  27  is suctioned by a transport device of a production device so that the tool member can be transported. 
   The supports  25  are formed with support holes  28  disposed according to the shape of the shield perimeter wall and into which the opposing ends of the plug  5  are inserted and fitted. In other words, in the plug attachment tool member  24 , the plugs  5  are supported by the supports  25  along the shape of the shield perimeter wall. 
   To mount the plugs  5  onto the secondary substrate  3  using the plug attachment tool member  24 , first the plugs  5  are supported on the plug attachment tool member  24 , and in this state, the suction section  27  is suctioned by the transport device of the production machine so that it is transported to a predetermined position over the substrate  3 , i.e., the plugs  5  are transported to a position where they will surround the electronic components  1  mounted on the substrate  3 . 
   As shown in  FIG. 12 , once transported to the predetermined position, the plugs  5  supported by the plug attachment tool member  24  are mounted on the secondary substrate  3 . Reflowing or the like is performed to connect the plug contact terminal pieces  17  and the securing piece  22  of the plug shield member  9  to the terminal pattern and the securing pattern formed on the secondary substrate  3 . The electronic components  1  can also be surface mounted on the secondary substrate  3  at the same time. 
   By removing the plug attachment tool member  24  from the plugs  5 , a secondary substrate assembly A is completed in which the plugs  5  are aligned with the shield perimeter wall, i.e., are surrounding the electronic components  1  on the secondary substrate  3 . 
   As shown in  FIG. 14  through  FIG. 19 , the socket  6  is equipped with: a socket housing  36  including a plug insertion hole  35  into which the plug  5  is inserted. Multiple socket contacts  37  can be supported by the socket housing  36  and project into the plug insertion hole  35 . A socket shield member  38  can fit to the outer side surface of the socket housing  36 . 
   The socket housing  36  can be formed from synthetic resin in the shape of a wide box with the plug insertion hole  35  opening up to the upper surface. 
   The socket housing  36  is formed with multiple contact attachment holes  39  that pass all the way through vertically and that communicate with the plug insertion hole  35 . The contact attachment holes  39  are disposed parallel to each other at a predetermined interval. The socket contacts  37  are inserted into the contact attachment holes  39  and are supported by them. 
   Engagement projections  40  are formed integrally with the outer side surfaces of the socket housing  36  to secure the socket shield member  38 . A bent connection piece  41  formed at the upper edge of the socket shield member  38  fits into an engagement cavity  42  formed at the edge of the opening of the plug insertion hole  35 . 
   As shown in  FIG. 20 , the socket contact  37  includes an attachment piece  43  supported by the socket housing  36 , a bent terminal  44  continuous with one end of the attachment piece  43 , and a first bend  45  bent in a “U” shape from the other end of the attachment piece  43 . A connecting piece  46  can be continuous with the other end of the first bend  45 . A second bend  47  can be bent arcuate from the other end of the connecting piece  46  and an elastic contact piece  48  can be continuous with the second bend  47  and extends diagonally upward. The socket contact  37  is formed by punching a conductive plate material such as copper alloy into a predetermined shape and bending it. 
   The attachment piece  43  is formed as a flat plate having a width roughly identical to that of the contact attachment hole  39 . Engagement projections  49  are formed integrally with the side edges of the attachment piece  43 . 
   The first bend  45 , the connecting piece  46 , and the second bend  47  are all formed with widths narrower than that of the attachment piece  43 . 
   The elastic contact piece  48  is bent diagonally upward from the end of the second bend  47 , and the tip is bent at an angle to form a contact  50 . 
   The terminal piece  44  is bent perpendicular so that it points inside the shield perimeter wall from one end of the attachment piece  43 . 
   The end of the terminal  44  opposite from the attachment piece  43  is connected integrally with a carrier plate  51 . Multiple socket contacts  37  are supported by the carrier plate parallel to each other and at a predetermined pitch, i.e., at the pitch used to attach the socket contacts  37  to the socket housing  36 . 
   The terminal  44  and the carrier plate  51  are formed with notches at the side edge of the connecting point so that once the socket contacts  37  are attached to the socket housing  36 , the terminal  44  and the carrier plate  51  can be easily separated. 
   The socket shield member  38  is equipped with a flat shield plate  52 , a bent connection piece  41  bent inward from the upper edge of the shield plate  52 , grips  53 ,  53  formed integrally with the side edges of the shield plate  52 , and securing pieces  54  projected outward from the lower edges of the grips  53 . The socket shield member  38  can be formed by bending a conductive metal plate. 
   The shield plate  52  is formed with engagement holes  55  at either end to engage with the engagement projections  40  of the socket housing  36 . Bent connection pieces  41  are formed integrally with the holes and are bent inward from the upper edges thereof. 
   The grips  53  can be formed by bending the side edges of the shield plate  52  in a square “C” shape, serve to grip the sides of the socket housing  36 . 
   A shield connection piece  56  projecting inwardly from the shield perimeter wall can be formed by forming a square “C”-shaped cut in one of the grips  53  and bending it at the base end of the cut. 
   The socket attachment tool member  57  is used to secure the sockets  6  to the substrate  2  so that the electronic components  1  are surrounded. 
   As shown in  FIG. 21 , the socket attachment tool member  57  is formed as a frame equipped with supports  58  projecting from the four edges of one side. A circular suction section  60  is supported at the center of the frame by supports  59 . This suction section  60  can be suctioned and transported by a transporting device of the production device. 
   The supports  58  are arranged in the shape of the shield perimeter wall, and are set up so they can be inserted and fitted into the plug insertion holes  35 . In other words, with this socket attachment tool member  57 , the sockets  6  are supported by the supports  58  so that they are aligned with the shape of the shield perimeter wall. 
   To mount the socket onto the main substrate  2  using the socket attachment tool member  57 , the socket attachment tool member is first used to support the sockets  6 . Then, the suction section  60  is suctioned by the automated transporting device and transported to a predetermined position over the substrate, i.e., a position where the sockets  6  would surround the electronic components  1  mounted on the main substrate  2 . 
   As shown in  FIG. 22 , once sockets  6  have been transported to the predetermined position, the sockets  6  are mounted on the main substrate  2  while still being supported by the socket attachment tool member  57 . From this state, reflowing or the like is used to secure the socket contact terminal pieces  44  and the securing pieces  54  of the socket shield member  38  to the terminal pattern and securing pattern formed on the main substrate  2 . It would also be possible to have the electronic components  1  surface mounted on the main substrate  2  at the same time. 
   Finally, the socket attachment tool member  57  is removed from the sockets  6 . As shown in  FIG. 23 , this completes a main substrate assembly B, in which the sockets  6  are mounted in alignment with the shield perimeter wall, i.e., so that they surround the electronic components  1  on the main substrate  2 . 
   In the main substrate assembly B, the socket shield member  38  includes shield connection pieces  56  so that when the sockets  6  are attached, the shield connection pieces  56  come into contact with the socket shield members  38  of the sockets  6  adjacent along the perimeter. Thus, the gaps between sockets adjacent to each other along the perimeter are shielded, resulting in an improved shield. 
   In this type of shield structure, the main substrate assembly B is connected to the secondary substrate assembly A, thus connecting the plugs  5  to the sockets  5  and providing electrical connection between the main substrate  2  and the secondary substrate  3 . As a result, the electronic components  1  mounted on the main and secondary substrates  2 ,  3  can form a single electronic circuit. 
   Also, by having the electronic circuit surrounded by a shield perimeter wall, i.e., the main substrate  2 , the secondary substrate  3 , and the multiple shielded substrate connectors  4 , the electronic circuit formed from the electronic components  1  within the wall can be shielded. 
   Furthermore, since the socket shield member  38  includes shield connection pieces  56 , the shield connection pieces  56  can come into contact with socket shield members  38  adjacent to each other along the perimeter, thus shielding the spaces between sockets adjacent to each other along the perimeter. In other words, the shield connection piece  56  connects the space between shielded substrate connectors  4  that are adjacent to each other along the perimeter so that a tight shield is provided. 
   In the embodiment described above, the plug is mounted on the secondary substrate  3  and the socket is mounted on the main substrate  2 , but the plug  5  and the socket  6  can be mounted on either the main or secondary substrate  2 ,  3 . 
   Also, in the embodiment described above, the shielded substrate connectors  4  are arranged in a four-sided shape, but the electronic components can be surrounded using other polygonal shapes. 
   Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.