Patent Publication Number: US-7594826-B2

Title: Connector

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to a connector, and more specifically, to a right angle type socket connector which is used for high speed transmission to electrically connect a cable with a print wired substrate for a communication apparatus or the like. 
   2. Description of the Related Art 
   Conventionally, a communication apparatus includes a print wiring substrate in it, on which is mounted a right angle type socket connector at an edge of the print wiring substrate. A socket part of the right angle type socket connector is configured to stick out from an opening of a panel of the communication apparatus. The communication apparatus is used with a condition in which the plug of a cable end is connected to the right angle type socket connector. 
   The right angle type socket connector includes numerous contact parts which project in the front side and are arrayed vertically and horizontally, and includes numerous terminal parts which project and are arranged vertically and horizontally. 
   The contact part is where the arrayed contacts of the plug are connected. The terminal part includes arrayed terminals which are connected to the terminals of the print wiring substrate by solder or press-fitting. The contact part and the terminal part are arranged at a right angle from a side view of the socket connector. 
   In recent these years, with an increasing capacity of signal transmission, communication systems are required to increase the transmission speed of signals and place shields between signals to be transmitted. It is also required to increase the impedance of signal transmission lines. 
   As a socket connector forms part of the signal transmission lines, the shielding of individual signals, which signals propagate along the transmission lines of signal contacts, is required to increase the impedance of individual signal transmission lines for socket connectors. 
   For example, a conventional socket connector includes plural contact module assemblies. The individual assemblies have mounted a print wiring substrate with a small size and approximately rectangular shape. The contact module assemblies are configured to face each other. Signal transmission lines are formed on a print wiring substrate as a pattern, and it is possible to increase shielding characteristics of signals and impedance of the signal transmission lines with a suitable design of a print wiring substrate. 
   In addition to the print wiring substrate, the contact module assembly needs to provide a contact part arranged by plural contact parts and a terminal part including terminal elements, and those are respectively fixed on individual sides of the print wiring substrate by soldering. Further, the module needs a cleaning treatment and inspection of the condition of the module after soldering. Thus, such a contact module assembly needs process steps for construction. 
   Further, in  FIG. 1 ,  FIG. 2A , and  FIG. 2B  in Japanese Published Patent Application 2003-522386, it is shown that a first half wafer and a second half wafer are stacked to form a unit wafer, and plural unit wafers are placed to face each other and arranged in a socket. The first half wafer has an approximate shape of a small piece of a half plate which is configured by a first signal element and a ground connection element by insert molding. The second half wafer has an approximate shape of a small piece of half plate which is configured by insert molding. The fabrication process of the socket connector is easier than that of the print wiring substrate described above. 
   Patent document 1 Japanese Published Patent Application 2003-522386. 
   The following are issues. A wafer includes a first signal element and a second signal element facing each other, and a ground element having a line shape arranged between adjacent first elements. Thereby, it is difficult for the ground element to shield the first element and the second element. 
   Further, both the first and second elements are entirely surrounded by resin, and increasing its impedance is difficult. Further, the first and second elements are not formed to have microstrip line structures, which make it difficult to design the impedance for fitting a specification of a connector. 
   One aspect of the present invention may provide a connector for reducing the issues above. 
   SUMMARY OF THE INVENTION 
   Accordingly, embodiments of the present invention may provide a novel and useful apparatus and method solving one or more of the problems discussed above. 
   More specifically, the embodiments of the present invention may provide a connector including a housing and a plurality of contact module assemblies in the housing, wherein each contact module assembly includes: a first signal contact module where a first signal contact body is inserted in a first resin molded part; a second signal contact module where a second signal contact body is inserted in a second resin molded part, and a ground plate, wherein the ground plate is sandwiched by the first signal contact module and the second signal contact module, so that a microstrip line structure is formed, and wherein, in the microstrip line structure, the first signal contact body and the second signal contact body form a stripline conductor, the first resin molded part and the second resin molded part form a dielectric board, and the ground plate forms a common ground conductor. 
   According to one aspect of the present invention, there are several effects as follows. 
   (1) The connector has an assembled structure and includes a microstripe line structure. A first signal contact and a second signal contact form a signal transmission line, so that the impedance of the signal transmission line is easy to design for adapting for a specification of the connector. 
   (2) A ground plate is sandwiched between the first signal contact and the second signal contact, which improves the signal-shielding effect between the first signal contact and the second signal contact. 
   (3) The effects of paragraphs (1) and (2) provide high speed signal transmission. 
   (4) A contact module assembly is configured by placing a ground plate between a first signal contact module and a second signal contact module, which provides easy construction. 
   (5) A ground plate is configured as a common ground conductor; thus, only a single ground plate may be used, so that the number of parts may be reduced. 
   Other objects, features, and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective diagram showing a socket connector according to a first embodiment of the present invention, a print wiring substrate for mounting the socket, and a connector of a cable end to insert and connect the socket; 
       FIG. 2  shows a perspective diagram of the socket connector of  FIG. 1  separated into parts; 
       FIG. 3  is a plan view of the socket connector; 
       FIG. 4  is an illustration showing an enlarged front view of a socket connector and contact module assemblies arranged in the socket; 
       FIG. 5  is an illustration showing an enlarged bottom view of a socket connector and contact module assemblies being arranged in the socket; 
       FIG. 6  shows an enlarged cross-sectional view of a connector including contact module assemblies arranged in view from a line VI-VI of  FIG. 3 ; 
       FIG. 7  is a perspective view of a contact module assembly separated into parts; 
       FIG. 8  shows an orthographic projection of a contact module assembly; 
       FIG. 9  shows an enlarged view of  FIG. 8(B) ; 
       FIG. 10  shows an enlarged cross-sectional view of the connector along a line X-X of  FIG. 8(A) ; 
       FIG. 11  shows an enlarged cross-sectional view of the contact module of  FIG. 8(B)  in view along a line XI-XI; 
       FIG. 12  shows an enlarged cross-sectional view of the contact module of  FIG. 8(A)  in view along a line XII-XII; 
       FIG. 13  shows an enlarged cross-sectional view of the contact module of  FIG. 8(A)  in view along a line XIII-XIII; 
       FIG. 14  shows an enlarged perspective view of the contact module in view of the circle indicated in  FIG. 7(A) ; 
       FIG. 15  shows a perspective view of a first signal contact insert molding module; 
       FIG. 16  shows an enlarged view of the signal contact insert molding module in view along a line XVI-XVI  FIG. 15(A) ; 
       FIG. 17  shows a perspective view of a first signal contact frame; 
       FIG. 18  shows a perspective view of a second signal contact insert molding module; 
       FIG. 19  shows an enlarged cross-sectional view of a second signal contact insert molding module in view along a line XVI-XVI in  FIG. 18(A) ; 
       FIG. 20  shows a perspective view of a second signal contact frame; 
       FIG. 21  shows a ground plate; 
       FIG. 22  shows a ground plate in view from Y 2  side; 
       FIG. 23  shows a ground plate in view from Z 2  side; and 
       FIG. 24  shows a modified example of a signal contact insert molding module. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the present invention is described below, with reference to  FIG. 1  through  FIG. 24 . 
   Embodiment 1 
     FIG. 1  shows a perspective diagram of a socket connector  10  according to a first embodiment of the present invention, corresponding to a print wiring substrate  20  on which to mount the connector  10 , and a cable connector  31  of an end of a cable  30  to insert in and connect to the connector  10 .  FIG. 2  shows the connector  10  in an exploded perspective view. The connector  10  is a right angle type which is suitable for single transmission. 
   X 1 -X 2 , Y 1 -Y 2 , and Z 1 -Z 2  indicate the directions in width, length, respectively, and height of the connector  10 . Y 2  indicates the front, and Y 1  indicates the back. 
     FIG. 3  shows a plan view of the socket connector  10 .  FIG. 4  shows a front view of the socket  10 , and  FIG. 5  is a bottom view of the connector  10 .  FIG. 6  shows a cross-sectional view of the connector  10  along the line VI-VI in  FIG. 3 . 
   For all figures, some signs for crowded parts are omitted. Plural identical parts are indicated with branch numbers. 
   Further, when an entire part is indicated for unspecified identical individual parts in the present specification, reference numbers and letters with no branch number are used. 
   The connector  10  includes a contact module assembly  40  tightly inserted in a housing  11  from the Y 1  side and plural (number n) contact module assemblies  40 - 1  through  40 - n  are arranged in X 1 -X 2  direction facing each other. A shield cover (not shown) covers a projection part of the contact module assembly  40 , which projects from the housing  11  to the Y 1  side, and an arrangement sheet  35 . 
   The housing  11  is a resin molded part. The housing  11  includes a rectangular frame  12  in the X 1 -X 2  direction. Ratchet arms  13  and  14  project from corresponding sides of the frame  12  in the Y 2  direction. Bosses  15  and  16  (see  FIG. 3 ) project from corresponding sides of the frame  12  in the Z 2  direction. 
   The front of the connector  10 , in the frame  12 , is provided with first and second signal contact parts  45 ,  145 , and ground contacts  72 , which are arranged as a matrix by a staggered arrangement in the X-Z plane as shown in  FIG. 4 . On the bottom of the connector  10 , there are first and second signal terminal parts  46 ,  146  (signal terminal parts  46 , 146 ), and ground terminals  73 , having press-fit structures, with a staggered arrangement as a matrix in the X-Y plane, as shown in  FIG. 5 . The arrangement sheet  35  includes the first and second signal terminal parts  46 ,  146 , and the ground terminals  73  which are tightly bound on the sheet  35  to be arranged as a matrix shape. 
   The bosses  15  and  16  (see  FIG. 3 ) of the connector  10  are fitted into holes  21  and  22  (see  FIG. 1 ) of the print wiring substrate  20  for positioning, with a position of detaching the arrangement sheet  35 , and the signal terminal parts  46 - 1 ,  146 - 1 , and the like, and the ground terminal  73 - 1  and the like are press fit into terminal holes  23  of the print wiring substrate  20  to mount the connector  10  on the print wiring substrate  20  and fixed without soldering. 
   [Schematic Diagram of Contact Module Assembly  40  Structure] 
     FIG. 7(A)  is a perspective schematic diagram of the contact module assembly  40  viewed from the X 1  side, also showing its exploded view.  FIG. 7(B)  is a perspective schematic diagram of the contact module assembly  40  viewed from the X 2  side.  FIG. 8  shows a projection-drawing of the contact module assembly  40 . 
     FIG. 8  shows an orthographic projection of  FIG. 8(B) . 
     FIG. 10  is an enlarged cross-sectional diagram of  FIG. 8(A)  taken along line X-X.  FIG. 11  is an enlarged cross-sectional diagram of  FIG. 8(B)  taken along line XI-XI, and  FIG. 12  is an enlarged cross-sectional diagram of  FIG. 8(A)  in view of a line XII-XII.  FIG. 13  is an enlarged cross-sectional diagram of  FIG. 8(A)  taken along line XIII-XIII.  FIG. 14  is an enlarged diagram of a part encircled by a line XIV in  FIG. 7(A) . 
   As shown in  FIG. 7 , the contact module assembly  40  includes a ground plate  70  sandwiched between first and second signal contact insert molded modules  41  and  141  as a unit assembly and having a microstrip line on the first signal contact insert molded module  41  side and another microstrip line on the second signal contact insert molded module  141  side. 
   [Structure of First Signal Contact Insert Molded Module  41 ] 
     FIG. 15(A) ,  FIG. 15(B) , and  FIG. 16  show the first signal contact insert molded module  41  (first module  41 ).  FIG. 16  is an enlarged cross-section drawing at an encircled part of  FIG. 15(A)  taken along line XVI-XVI.  FIG. 17  shows a perspective diagram of a first signal contact frame  42 . 
   For forming the first signal contact insert molded module  41 , the first signal contact frame  42  is set on a die (not shown) of a resin molding machine (not shown) and synthetic resin is injected into the die for insert molding so that one side of a first signal contact member  43  is covered with the resin and the another side is exposed. Then the member is removed from the die and finally the contact frame  42  is removed to complete the module  41 . The first signal contact insert molded module  41  includes first signal contact members  43 - 1  through  43 - 4 , and a first resin molded part  50  (see  FIG. 16 ). 
   For the contact module assembly  40  shown in  FIG. 7  and  FIG. 8 , the first signal contact members  43 - 1  through  43 - 4  form striplines of the microstrip line structure and the first resin molded part  50  forms a dielectric substrate of the microstrip line structure. 
   [First Signal Contact Frame  42 ] 
   The first signal contact frame  42  includes first signal contact members  43 - 1  through  43 - 4  formed by four lines arranged at a pitch p 1 , and whose edges are connected to the frame  42 , as shown in  FIG. 17 . The first signal contact members  43 - 1  through  43 - 4  include first signal contact bodies  44 - 1  through  44 - 4 , having approximately L shapes, first signal contact parts  45 - 1  through  45 - 4  at an edge Y 2  of the first signal contact body  44 , and first signal terminal parts  46 - 1  though  46 - 4  at an edge Z 2  of the first signal contact body  44 . The first signal contact bodies  44 - 1  through  44 - 4  include approximately square cross sections with sides A. The first signal contact parts  45 - 1  through  45 - 4  include conventional pin shapes. The first signal terminal parts  46 - 1  through  46 - 4  include press-fit pin shapes. 
   [First Resin Molded Part  50 ] 
   A first resin molded part  50  includes planes  51 X 1  on the X 1  side and  52 X 2  on the X 2  side, with an approximately rectangular shape. The first resin molded part  50  includes a maximum thickness B (corresponding to thicknesses of projection parts  53 ,  54 , and  55 ), which is approximately twice the thickness of the above side A. 
   The plane  51 X 1  includes the projection parts  53 ,  54 ,  55  along Y 1 , Y 2 , and Z 2  directions, respectively. An inner part of the first resin molded part  50 , a large part surrounded by the projection parts  53 ,  54 , and  55  includes a concave part having a thickness B 1  less than the thickness B above. 
   As for the plane  51 X 1  including the above shape, there is the following structure: (1) the first signal contact body  44 - 1  and the like is placed at about the center of the thickness B, a thickness E from the bottom of the first signal contact body  44 - 1  and the plane  52 X 2  is set as a predetermined value, and one side is placed on the same plane with the  51 X 1  plane; (2) The entire peripheral part of the first signal contact body  44  is surrounded by the projection parts  54  and  55  for both edges; (3) The first signal contact part  45  projects from an approximate thickness center of the first resin molded part  50 ; (4) The first signal terminal part  46  projects from an approximate thickness center of the first resin molded part  50 . Further, the convex shapes of the projection parts  53 ,  54 , and  55  play a role to improve the mechanical strength of the first signal contact insert molded module  41 . 
   For the contact module assembly  40 , the thickness E above corresponds with a dimension between the first signal contact body  44  and the ground plate  70 , in which the dimension related to a factor that determines the impedance of the first signal contact body  44 . 
   On the projection part  53 , a stop through-hole  56  is formed through the projection part  53  at an approximately center height of the first resin molded part  50 . On the Z 2  end of the projection part  54 , a stop through-hole  57  is formed. 
   The plane  52 X 2  includes a square stop projection  58  next to the through hole  56  on the Z 1  end. 
   At the Y 2  end of the Z 1  and Z 2  side planes of the first resin molded part  50 , a guide projection  59  is formed to fix the housing  11  (see  FIG. 15 ). 
   [Structure of First Resin Molded Part  50  and First Signal Contact Frame  42 ] 
   The first signal contact body  44 - 1  is fixed on the first resin molded part  50 , which surrounds and buries a Z 1  side plane  44 - 1 Z 1 , a Z 2  side plane  44 - 1 Z 2 , and an X 2  side plane  44 - 1 X 2  of the first signal contact body  44 - 1 , as shown in  FIG. 16  as enlarged. The X 1  side plane  44 - 1 X 1  is exposed from the plane of  51 X 1 . This is to obtain predetermined impedance, which is discussed below. The projection parts  53  and  54  and the entire peripheral part of the first signal contact body  44 - 1  are surrounded by the resin. Thus, two edges of the first signal contact body  44 - 1  are surrounded and fixed by resin. In the Y 1  side part of the projection part  54 , facing a thin part of the first resin molded part  50 , there are plural slits  60  formed in the projection part  54 . At the slit  60 , the first signal contact body  44  is exposed and the exposed part of the first signal contact body  44  is extended to Y 2  direction (See  FIG. 12  and  FIG. 14 ). Thus, the first signal contact insert molded module  41  is formed to have predetermined mechanical strength and includes extended exposed parts of the first signal contact body  44 . 
   Likewise for the first signal contact body  44 - 1  above, the other first signal contact bodies  44 - 2 ,  44 - 3 , and  44 - 4  are formed in the first resin molded part  50  and include parts exposed from the X 1  side. 
   On the plane  51 X 1  of the first resin molded part  50 , first grooves  61 - 1  through  61 - 4  are formed along the inside of the first signal contact bodies  44 - 1  through  44 - 4  (for individual first signal contact bodies  44 - 1  through  44 - 4  at the Z 2  side and the Y 2  side). Individual grooves  61 - 1  through  61 - 4  include dimensions of a width C and a depth D. The width C approximately corresponds with the pitch p 1  above, being approximately twice the dimension A above. The dimension of the depth D is slightly longer than the dimension A. For the connector  10 , the grooves  61 - 1  through  61 - 4 , next to the plane exposing the first signal contact bodies  44 - 1  through  44 - 4  of the contact module assembly  40 , are formed to make an air layer (free space)  201 - 1  and the like shown in  FIG. 6 . 
   The first signal contact parts  45 - 1  through  45 - 4  project from the edge plane at the Y 2  side of the first resin molded part  50  and align with pitch p 1 , and the first signal terminal parts  46 - 1  through  46 - 4  project from the edge plane at the Z 2  side and align with a pitch p 2 . 
   On the plane  52 X 2  of the first resin molded part  50 , at the Y 2  edge plane and at positions adjacent first signal contact parts  45 - 1  through  45 - 4  or a close position to the Z 2  side compared to the first signal contact parts  45 - 4 , slits  62 - 1  through  62 - 4  are formed. 
   Likewise, a Z 2  side edge plane of the plane  52 X 2  forms slits  63 - 1  through  63 - 4  at positions of the first signal terminal parts  46 - 1  through  46 - 4  and the Y 2  side from the first signal terminal part  46 - 4 . The slits  62 - 1  through  62 - 4  are formed to insert the bent part of the root of the ground terminals  73 - 3  and the like. 
   [Structure of Second Signal Contact Insert Molded Module  141 ] 
     FIGS. 18(A) , (B), and  FIG. 19  show the second signal contact insert molded module  141  (second module  141 ).  FIG. 19  shows an enlarged cross-sectional view of the part of  FIG. 18(A)  taken along line XIX-XIX.  FIG. 20  shows a second signal contact frame  142 . 
   The second signal contact insert molded module  141  is formed to have approximately plane symmetry to the first signal contact insert molded module  41  at the plane  51 X 1 , where individual corresponding parts are indicated by part numbers with 100 added. 
   The second signal contact insert molded module  141  is formed of an insert resin molded module and includes second signal contact members  143 - 1  through  143 - 4  and the second resin molded part  150 . 
   The second signal contact bodies  144 - 1  through  144 - 4  are exposed from a plane  151 X 2  at the X 2  side of the second contact insert molded module  141 . 
   When the first signal contact insert molding module  41  and the second signal contact insert molded module  141  are stacked, and when those modules are seen from the X 1  side, the second signal contact members  143 - 1  through  143 - 4  are formed to shift by a half pitch p 1  toward Z 2  side compared to the first signal contact members  43 - 1  through  43 - 4  (See  FIG. 8(A)  and  FIG. 10 ). The second signal contact parts  145 - 1  through  145 - 4  are formed at positions set off from the first contact parts  45 - 1  through  45 - 4  by a half pitch p 1  toward Z 2  side. This is to embody a staggered structure for the first signal contact parts  45 - 1  through  45 - 4  and the second signal contact parts  145 - 1  through  145 - 4  in the contact module assembly  40 , as shown in  FIG. 9 . The second signal terminal parts  146 - 1  through  146 - 4  are formed at positions set off from the first signal terminal parts  46 - 1  through  46 - 4  by a dimension of a quarter pitch p 2  toward Y 2  side (See  FIG. 5  and  FIG. 8(C) ). 
   The second grooves  161 - 1  through  161 - 4  are formed on the plane  152 X 2  and along the outside of individual second signal contact bodies  144 - 1  through  144 - 4  (at Z 1  side and Y 1  side to individual second signal contacts  144 - 1  through  144 - 4 ). 
   The plane  151 X 1  forms a stop hole  158  to correspond to the stop projection  58 . 
   For the contact module assembly  40  shown in  FIG. 7  and  FIG. 8 , the second signal contact members  143 - 1  through  143 - 4  form strip conductors of the microstrip line structure, and the second resin molded part  150  forms a dielectric substrate of the microstrip line structure. 
   [Shape of Ground Plate  70 ] 
     FIGS. 21(A)  and (B) show the ground plate  70 .  FIG. 22  shows a side view of the ground plate  70  from the Y 2  direction, and  FIG. 23  is a side view of the ground plate  70  from the Z 2  direction. 
   The ground plate  70  forms a ground conductor of the microstrip line structure. As the ground plate  70  is used in common for an X 1  side ground conductor of the microstrip line structure and an X 2  side ground conductor of the microstrip line structure in the contact module assembly  40 , a single ground plate  70  is enough for the contact module assembly  40 , as described below. 
   The ground plate  70  includes a ground plate member  71 , plural ground contact members  72  that project from the Y 2  side projection part  71 Y 2  of the ground plate member  71  to the Y 2  direction, and plural ground terminals  73  that project from the Z 2  side projection part  71 Z 2  of the ground plate member  71  to the Z 2  direction. 
   The ground plate member  71  has a size and a shape to entirely cover the first and second signal contact bodies  44  and  144 , and has almost the same size and shape as the first module  41  and the second module  141  (See  FIG. 7 ). The ground contact member  72  includes a conventional pin shape and the ground terminal member  73  includes a press fit shape. 
   The ground contact members  72  are aligned with a pitch p 3 , and individual contact members  72  are bent at each base part to the X 2  side and the X 1  side respectively, forming a staggered shape as shown in  FIG. 6 . 
   The ground terminal members  73  are bent at each base part of the terminal member  73  to the X 2  side and the X 1  side respectively and form a staggered shape for approximately the X 2  side and the X 1  side as shown in  FIG. 6 . 
   The ground terminal  73  includes ground terminal members  73 - 1  and  73 - 8  at corresponding edges in the Y 1 -Y 2  directions and pairs of ground terminal members  73 - 2 ,  73 - 3 ,  73 - 4 ,  73 - 5 ,  73 - 6 , and  73 - 7  in between the two terminal members (see  FIG. 21 ). 
   Further, a first fixing part  74  is formed by bending an end of the ground plate member  71  to the X 1  direction on the Y 1  side projection part  71 Y 1  and a second fixing part  75  is formed by bending another end of the ground plate member  71  to the X 2  direction on the Y 1  side projection part  71 Y 1  (see  FIG. 21 ). 
   The ground plate member  71  forms another second fixing part  76  on a the Y 2  side projection part  71 Y 2  bending to the X 2  direction and another first fixing part  77  on the Y 2  side projection part  71 Y 2  bending to the X 1  direction. 
   Further, extended parts  78  through  81  are formed on a projection part  71 Z 2  extended in the Z 2  direction, and the extended parts  78  through  81  are formed between the ground terminal members  73 - 1  and  73 - 2 , and between the members  73 - 3  and  73 - 4 , between members  73 - 5  and  73 - 6  and between members  73 - 7  and  73 - 8 , respectively. 
   [Structure of Contact Module Assembly  40 ] 
   The contact module assembly  40  is provided as a unit structure formed by stacking a pair of the first and second signal contact insert molded modules  41  and  141  with the ground plate  70  sandwiched between the modules  41  and  141 , as shown in  FIG. 7 . 
   The contact module assembly  40  is assembled, for example, where the second module  141  is put with its plane  151 X 1  facing upward on a work table and the ground plate  70  is pressed onto the second module  141 . Then the first module  41  is pressed onto the ground plate  70  having its plane  51 X 1  facing upward and all of them are tightly pressed. No soldering is necessary. Also, a cleaning treatment, which would be needed if the soldering were performed, is not necessary. Therefore, assembling the contact module assembly  40  is simple. 
     FIG. 12  shows an assembled configuration of the ground plate  70  and the first and second modules  41  and  141 . As shown in  FIG. 13 , for the ground plate  70  and the second module  141 , a second fixing part  75  of the ground plate  70  is pressed to fit into a stop hole  156  and a second fixing part  76  is pressed to fit into the stop hole  157  for fixing their positions. 
   A bottom part of the ground contact member  72  bent toward the X 2  side is fit into a slit  63  and a bottom part of the ground terminal  73  bent toward the X 2  side is fit into a slit  63 . 
   The first signal contact insert molded module  41  is assembled with the ground plate  70  of  FIG. 11  stacked. As shown in  FIG. 13 , a first fixing part  74  is pressed to fit into a stop hole  56 . A first fixing part  77  is pressed to fit into a stop hole  57 , as shown in  FIG. 12 . Further, a stop projection  58  is pressed into a stop hole  158 , so that the first module  41  is positioned and fixed to the ground plate  70  and the second module  141 , as shown in  FIG. 13 . A bottom part of the contact part  72  bent toward the X 1  side is pressed to fit into a slit  62 , and a bottom part of the contact part  73  bent toward the X 1  side is pressed to fit into a slit  62 . 
   Although the bottom parts of the ground contact members  72  and ground terminals  73  are projected toward the plane of the ground plate  71 , those projected parts are placed within the slits  62 ,  162 , so that the projected parts are not blocked by the bottom parts of the contact parts  72  and  73 . Thus the first module  41 , the second module  141  and the ground plate  70  tightly fit together, as shown in  FIG. 10 . 
   As shown in  FIGS. 12 and 13 , the ground plate  70  and the first module  41  are fixed with two stop parts apart from each other, that is, the first fixing part  74  is fixed into the stop hole  56  at the Y 1  side and the first fixing part  77  is fixed into the stop hole  57  at the Y 2  side. 
   The ground plate  70  and the second module  141  are fixed with two stop parts apart from each other, in which the second fixing part  75  is fixed into the stop hole  156  at the Y 1  side and the second fixing part  76  is fixed into the stop hole  157  at the Y 2  side. 
   The first module  41  and the second module  141  are fixed through the ground plate  70  and fixed by using the stop projection  58  and the stop hole  158 . 
   [Configurations of First Signal Contact Bodies  44 - 1  Through  44 - 4 , the Second Signal Contact Bodies  144 - 1  Through  144 - 4 , and Ground Plate  70 ] 
   As shown in  FIG. 10 , the first signal contact bodies  44 - 1  through  44 - 4  face on the ground plate  70  via the first resin molded part  50 . The first signal contact bodies  44 - 1  through  44 - 4  constitute striplines, the first resin molded part  50  constitutes a dielectric substrate, and the ground plate  70  constitutes a ground conductor. The first signal contact bodies  44 - 1  through  44 - 4 , the first resin molded part  50  and the ground plate  70  constitute a microstrip line structure. The transmission line including the first signal contact bodies  44 - 1  through  44 - 4  provide impedance required by the specification of the socket connector  40  (a contact module assembly  40 ) of  FIG. 1  by adjusting the size E (see  FIG. 16 ) and the like accordingly. 
   Likewise, as shown in  FIG. 10 , the second signal contact bodies  144 - 1  through  144 - 4  face the ground plate  70  via the second resin molded part  150 . The second signal contact bodies  144 - 1  through  144 - 4  constitute striplines, the second resin part  150  constitutes a dielectric substrate, and the ground plate  70  constitutes a ground conductor. The second signal contact bodies  144 - 1  through  144 - 4 , the second resin molded part  150  and the ground plate  70  constitute a microstrip line structure. The transmission line including the second signal contact bodies  144 - 1  through  144 - 4  provide impedance required by the specification of the socket connector  40  (contact module assembly  40 ) of  FIG. 1  by adjusting the dimension E and the like according. 
   Therefore, the contact module assembly  40  includes microstrip line structures on both sides X 1  and X 2 , and the individual stripline structures are provided with the ground plate  70  as a common ground conductor. 
   The backsides of the first signal contact bodies  44 - 1  through  44 - 4  and the second signal contact bodies  144  through  144 - 4 , not facing the ground plates  70 , are exposed to the air having a dielectric constant 1.00, and an electromagnetic field is formed in a free space over the first resin molded part  50  and the second resin molded part  150 . This structure is appropriate to tune the impedance. 
   [Configurations of First Signal Contact Bodies  44 - 1  Through  44 - 4 , the Second Signal Contact Bodies  144 - 1  Through  144 - 4 , First Grooves  61 - 1  Through  61 - 4 , and Second Grooves  161 - 1  Through  161 - 4 ] 
     FIG. 8(A)  and  FIG. 10  show that the first signal contact bodies  44 - 1  through  44 - 4  face the X 1  side of the contact module assembly  40  and the second signal contact bodies  144 - 1  through  144 - 4  face the X 2  side of the contact module assembly  40 . 
   The X 2  side of the contact module assembly  40  corresponding to the first signal contact bodies  44 - 1  through  44 - 4  includes the second grooves  161 - 1  through  161 - 4 . The X 1  side of the contact module assembly  40  corresponding to the second signal contact bodies  144 - 1  through  144 - 4  includes the first grooves  61 - 1  through  61 - 4 . 
   A view of the contact module assembly  40  from the X 1  side, in which the first molded module  41  stacks on the second molded module  141 , shows that the signal contact bodies  44 - 1  through  44 - 4  and the second signal contact bodies  144 - 1  through  144 - 4  are alternately aligned. The backsides of the first signal contact bodies  44 - 1  through  44 - 4  are provided with the second grooves  161 - 1  through  161 - 4  along the first signal contact bodies  44 - 1  through  44 - 4 . The first signal contact bodies  44 - 1  through  44 - 4  correspond to the second grooves  161 - 1  through  161 - 4 . Further, the backsides of the first grooves  61 - 1  through  61 - 4  are provided with the second signal contact bodies  144 - 1  through  144 - 4  along the second grooves  161 - 1  through  161 - 4 . The first grooves  61 - 1  through  61 - 4  correspond to the second signal contact bodies  144 - 1  through  144 - 4 . 
   [Arrangement of First Signal Contact Parts  45 - 1  Through  45 - 4 , Second Signal Contacts  145 - 1  Through  145 - 4 , and Ground Part  72 - 1  Through  72 - 8 ] 
   As shown in  FIG. 9 , the first signal contact parts  45 - 1  through  45 - 4  and the second signal contact parts  145 - 1  through  145 - 4  are arranged as a first staggered shape and the ground contacts  72 - 1  through  72 - 8  are arranged as a second staggered shape opposite to the first staggered shape. The staggered shapes are arranged as two lines. 
   For the X 1  side row, the first signal contact parts  45 - 1  through  45 - 4  and the ground contacts  72  line up alternately. For the X 2  side row, the second signal contact parts  145 - 1  through  145 - 4  and the ground contacts  72  line up alternately. 
   [Arrangement of First Signal Terminal Parts  46 - 1  Through  46 - 4 , Second Signal Terminal Parts  146 - 1  Through  146 - 4 , and Ground Terminal Members  73 - 1  Through  73 - 8 ] 
   As shown in  FIG. 8(C) , the first signal terminal parts  46 - 1  through  46 - 4  and the second signal terminal parts  146 - 1  through  146 - 4  are arranged as a third staggered shape and the ground terminal members  73 - 1  through  73 - 8  are arranged as a fourth staggered shape opposite to the third staggered shape. The staggered shapes are arranged as two lines. 
   For the X 1  side row, odd numbered ground terminal members  73 - 1 ,  73 - 3 ,  73 - 5  and  73 - 7  and the first signal terminal parts  46 - 1  through  46 - 4  are alternately arranged in a line. For the X 2  side row, even numbered ground terminal members  73 - 2 ,  73 - 4 ,  73 - 6  and  73 - 8  and the second signal terminal parts  146 - 1  through  146 - 4  are alternately arranged in a line. 
   [Configuration of First Signal Contact Bodies  44 - 1  Through  44 - 4 , Second Signal Contact Bodies  144  Through  144 - 4 , Ground Plate  71  and Extended Part  78  Through  81 ] 
   As shown in  FIG. 7(A)  and  FIG. 11 , the ground plate member  71  has approximately the same size as the first resin molded parts  50  and  150 . The space between the first signal contact bodies  44 - 1  through  44 - 4  and the second signal contact bodies  144 - 1  through  144 - 4  are sealed by the ground plate member  71 . 
   The extended part  78  is located at a position  44 - 1   a  (see  FIG. 11 ) near the first terminal part  46 - 1  of the first signal contact  44 - 1  and located at a position  144 - 1   a  (see  FIG. 11 ) near the second signal terminal part  146 - 1  of the second signal contact  144 - 1 . The extended part  78  provides a shield between the positions  44 - 1   a  and  144 - 1   a.    
   The extended part  79  shields between the positions  44 - 2   a  and  144 - 2   a . The extended part  80  shields between the positions  44 - 3   a  and  144 - 3   a . The extended part  81  provides a shield between the positions  44 - 4   a  and  144 - 4   a.    
   Thereby, the first signal contact bodies  44 - 1  through  44 - 4  are shielded from the second signal contact bodies  144 - 1  through  144 - 4  for their entire length. 
   Further, the first signal contact bodies  44 - 1  through  44 - 4  and the second signal contact bodies  144 - 1  through  144 - 4  form microstrip line structures by existence of the extended parts  78  through  81  even for parts near the first and second signal terminal parts  46 ,  146 , so that microstrip line structure is provided for their entire length. 
   [Configuration of Adjacent Contact Module Assembly  40  in Connector  10 ] 
   Individual contact module assemblies  40  are inserted into the frame  12  of the housing  11  to reach the end (not shown) of the frame  12 , and arranged in direction of X 1 -X 1  facing each other with no separation. The projection parts  59  and  159  of the first and second modules  41 ,  141  are pressed to touch the ceiling and the bottom of the frame  12 . Individual contact module assemblies  40  are fixed with the housing  11  by friction caused between the projection parts  59 ,  159  and the frame  12 . 
   With reference to  FIGS. 4 ,  5  and  6 , assembled configurations of adjacent contact module assemblies  40 - 1 ,  40 - 2  and  40 - 3  (first, second and third contact module assemblies  40 - 1 ,  40 - 2  and  40 - 3 ) are described. 
   Shield and Impedance of Transmission Line from First Signal Contact Part  45 - 2  of Second Contact Module Assemblies  40 - 2  Through First Signal Contact Body  44 - 2 , First Signal Terminal Part  46 - 2 , Second Signal Contact Part  145 - 2 , Second Signal Contact Body  144 - 2  and Second Signal Terminal Part  146 - 2 
 
&lt;First Signal Contact Part  45 - 2  and Second Signal Contact Part  145 - 2 &gt;
 
   As shown in  FIG. 4 , the first signal contact part  45 - 2  is located between the ground contact  72 - 2  at the Z 1  side, the ground contact  72 - 4  at the Z 2  side, the ground contact (the ground contact of the third contact module assembly  40 - 3 ) at the right side and the ground contact  72 - 3  at the X 2  side. 
   The second signal contact part  145 - 2  is located between the ground contact  72 - 3  at the Z 1  side, the ground contact  72 - 5  at the Z 2  side, the ground contact  72 - 4  (the ground contact of the second contact module assembly  40 - 2 ) on the right side and the ground contact of the first contact module assembly  40 - 1  on the left, X 2  side. 
   Likewise, the other first signal contact parts  45 - 1 ,  45 - 3 ,  45 - 4 , and the other second signal contact parts  145 - 1 ,  145 - 3 , and  145 - 4  are located in the same manner as the signal contact parts  45 - 2  and  145 - 2  described above. 
   Therefore, the first signal contact parts  45 - 1  through  45 - 4  and the second signal contact parts  145 - 1  through  145 - 4  are individually arranged so that the ground contacts are located between the adjacent signal contacts which are thus shielded. 
   &lt;First Signal Contact Body  44 - 2 &gt; 
   As shown in  FIG. 5  and  FIG. 6 , the first signal contact body  44 - 2  is shielded from the second signal contact bodies  144 - 1  and  144 - 2  by the ground plate  70  and the extended part  79  for its entire length. 
   The exposed part of the first signal contact body  44 - 2  faces the groove  161 - 2  of the third contact module assembly  40 - 3 , and the exposed part of the first signal contact body  44 - 2  faces an air layer  200 - 2 . Thereby, the impedance of the first signal contact body  44 - 2  is provided to be higher than a case where the first signal contact body  44 - 2  is entirely surrounded by resin, so that the predetermined impedance is obtained. 
   The first signal contact body  44 - 2  forms a stripline conductor, the first resin molded part  50  forms a dielectric substrate, and the ground plate  70  forms a ground conductor. The first signal contact body  44 - 2 , the first resin molded part  50  and the ground plate  70  form a microstrip line structure where an electromagnetic field is formed crossing over the first resin molded part  50  and the free space. 
   Likewise for the first signal contact body  44 - 2  as described above, the other first signal contact bodies  44 - 1 ,  44 - 3  and  44 - 4  are shielded from the second signal contact bodies  144  of the same contact module assembly  40  by the ground plate  70  and the extended parts  78 ,  80 , and  81  for its entire length. Further, the exposed parts of the first signal contact bodies  44 - 1 ,  44 - 3  and  44 - 4  individually face the grooves  161 - 1 ,  161 - 3  and  161 - 4  of the third contact module assembly  40 - 3 . Both sides of the exposed parts of the first signal contact bodies  44 - 1 ,  44 - 3 ,  44 - 4  have air layers  200 - 1 ,  200 - 3  and  200 - 4 , so that a predetermined impedance is obtained. Likewise the other first signal contact bodies  44 - 1 ,  44 - 3  and  44 - 4  form microstrip lines in the same manner described above. 
   &lt;Second Signal Contact Body  144 - 2 &gt; 
   As shown in  FIG. 5  and  FIG. 6 , the second signal contact body  144 - 2  is shielded from the first signal contact bodies  44 - 2  and  44 - 3  by the ground plate  70  and the extended part  79  for their entire length. 
   The exposed part of the second signal contact body  144 - 2  faces the groove  61 - 1  of the first contact module assembly  40 - 1 , and the exposed part of the second signal contact body  144 - 2  faces an air layer  201 - 2 . Thereby, the impedance of the second signal contact body  144 - 2  is made to be higher than a case where the first signal contact body  144 - 2  is entirely surrounded by resin, so that the predetermined impedance is obtained. 
   Further, the second signal contact body  144 - 2  forms a stripline conductor, the second resin molded part  150  forms a dielectric substrate, and the ground plate  70  forms a ground conductor. The second signal contact body  144 - 2 , the second resin molded part  150  and the ground plate  70  form a microstrip line structure where an electromagnetic field is formed crossing over the second resin molded part  150  and the free space. 
   Likewise for the second signal contact body  144 - 2  as described above, the other second signal contact bodies  144 - 1 ,  144 - 3  and  144 - 4  are shielded from the first signal contact bodies  44  of the same contact module assembly  40  by the ground plate  70  and the extended parts  78 ,  80 , and  81  for their entire length. Further, the exposed parts of the second signal contact bodies  144 - 1 ,  144 - 3  and  144 - 4  individually face the grooves  61 - 1 ,  61 - 3  and  61 - 4  of the first contact module assembly  40 - 1 . Both sides of the exposed parts of the second signal contact bodies  144 - 1 ,  144 - 3 ,  144 - 4  have air layers  201 - 1 ,  201 - 3  and  201 - 4 , so that a predetermined impedance is obtained. 
   Likewise the other second signal contact bodies  144 - 1 ,  144 - 3  and  144 - 4  form microstrip lines by the same manner described above. 
   &lt;First Signal Terminal Parts  46 - 1  Through  46 - 4  and Second Signal Terminal Parts  146 - 1  Through  146 - 4 &gt; 
   As shown in  FIG. 5 , the first signal terminal parts  46 - 1  through  46 - 4  and the second signal terminal parts  146 - 1  through  146 - 4  are arranged in a staggered shape and located between the ground terminals  73 - 1  through  73 - 8  which are aligned in an approximately staggered arrangement. 
   Modified Example 
   As shown in  FIG. 24 , for the first signal contact body  44 , the exposed part  44   a  may be formed as a concavity by a dimension S from the plane  51 X 1  of the first resin molded part  50 . Likewise, the second signal contact body  144  may be formed as a concavity from the plane of the second resin molded part  150   
   Although the invention has been described with respect to specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teachings herein set forth. 
   This patent application is based on Japanese Priority Patent Application No. 2008-048199 filed on Feb. 28, 2008, the entire contents of which are hereby incorporated by reference.