Abstract:
A shielded high-density edge connector comprises a metallic connector housing for accommodating several adjacently arranged segments with electric contacts held therein. The number of contacts between the mating side and the terminal side of the edge connector can be reduced by providing the contacts within the segments and the connector housing.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention pertains to a shielded high-density edge connector with a terminal side for connection to a mother board and a mating side for connection to a daughter board.  
       BACKGROUND OF THE INVENTION  
       [0002]     An edge connector of the above type is required for transferring differential signal voltages from a mother board to a daughter board by means of numerous electric contacts, wherein a shielding is provided to both sides of the contact pairs.  
         [0003]     Prior inventions in this field pertained to shielded connectors, in which an insulating housing for accommodating the electric contacts is surrounded by an electrically conductive folded and/or bent sheet-metal housing.  
       SUMMARY OF THE INVENTION  
       [0004]     An object of the present invention is to provide a shielding high-density edge connector in which the number of contacts on the terminal side to be connected to the circuit board can be reduced despite a contact arrangement of given density on the mating side of the connector, whereby the number of bores on the corresponding circuit board is reduced.  
         [0005]     This object is achieved by providing a connector having a metallic connector housing and an insulating connector insert, wherein the housing contains a plurality of discoidal segments with electric contacts that are embedded in insulating members, wherein the segments are respectively in the form of a ground segment or a signal segment, and in that the ground segment contains ground contact sections that protrude from the insulating member and contact the metallic connector housing.  
         [0006]     In a preferred embodiment of the invention the shielding edge connector housing is made of metal which has excellent dimensional stability; however it also is possible to form the housing of metallized plastic.  
         [0007]     The edge connector serves for connecting two circuit boards (also referred to as a mother board a daughter board) arranged perpendicular to one another.  
         [0008]     It would also be possible to attain a “straight” 180° connection if the contacts in the edge connector housing are designed accordingly.  
         [0009]     In adapting this high-density edge connector with adjacently arranged electric contacts embedded in accordance with wafer technology, the inventors aimed, in particular, to reduce the number of terminal contacts in order to disentangle the large number of strip conductors and their bores on the mother board. Since the contacts are adjacently arranged in a basic grid of 0.75 mm on the mating side, it is difficult to disentangle the signal paths leading to the bore holes on the terminal side. Consequently, it is necessary to either offset the individual rows of bores or to increase the spacing between the rows of bores.  
         [0010]     The connector of the present invention is designed for transferring differential signals by means of a direct mating with the strip conductors of the daughter board. Strip conductors are provided on both sides of the daughter board for this purpose.  
         [0011]     In this case, two adjacently arranged contacts on one side of the circuit board and two adjacently arranged contacts on the other side of the circuit board respectively form a differential signal pair.  
         [0012]     One of the upper and the lower contacts thereof also are combined into a signal segment.  
         [0013]     The two differential signal pairs consequently connect one circuit board to the other circuit board by means of two adjacently arranged signal segments. A ground segment advantageously is arranged to the right and the left of both signal segments in order to shield the signal pair relative to the next differential pair, wherein the contact sections of said ground segment are directly connected to the metallic connector housing, i.e., the connector is grounded because it is in contact with the connector housing due to its mounting on the mother board. This also makes it possible to safely touch the connector.  
         [0014]     It also is advantageous that the direct connection between the ground segments and the electrically conductive connector housing eliminates the need to produce these contacts individually on the mother board. This not only reduces the number of bores, but also makes it possible to increase the spacing between the bores and to simplify the disentanglement of the strip conductors.  
         [0015]     Consequently, the disentanglement is achieved by connecting only the signal contacts to the mother board via the connector while the ground contacts are connected to the mother board via an electrically conductive sleeve of the connector housing.  
         [0016]     However, one or more signal segments in the form of ground segments also may be connected to the circuit board in other variations of the connector. It is preferred that the signal segments and ground segments can be adjacently inserted into the connector housing in a certain configuration, wherein two signal segments are respectively shielded by a ground segment.  
         [0017]     Elongated structures extending in the mating direction are provided in the connector housing on the upper and the lower side thereof, wherein the signal segments can be inserted between these structures.  
         [0018]     In this case, the ground segments are inserted into the space of reduced height between the structures such that the signal segments and ground segments can be adjacently arranged within the connector housing in a closely staggered fashion.  
         [0019]     It also would be possible to provide a signal segment in the form of a double segment, wherein four electric contacts are embedded in an insulating housing instead of only two electric contacts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     One embodiment of the invention is illustrated in the figures and described in greater detail below. The figures show:  
         [0021]      FIG. 1   a  is a perspective view of an edge connector;  
         [0022]      FIG. 1   b  is a perspective view of the edge connector with the connector housing and the separately illustrated connector insert;  
         [0023]      FIG. 2   a  is a perspective view of the edge connector according to  FIG. 1   b  with separate segments;  
         [0024]      FIG. 2   b  is a cross section through the edge connector according to  FIG. 2   a;    
         [0025]      FIG. 3  is a side elevational view of a portion of the terminal side of the edge connector;  
         [0026]      FIG. 4   a  is a perspective representation of a ground segment  10 ;  
         [0027]      FIG. 4   b  is a top plan view of the ground segment  10  of  FIG. 4   a;    
         [0028]      FIG. 5   a  is a perspective view of a signal segment  11 ;  
         [0029]      FIG. 5   b  is a side elevational view of the signal segment  11  of  FIG. 5   a;    
         [0030]      FIG. 6   a  is a perspective view of a signal segment  12 ;  
         [0031]      FIG. 6   b  is a side elevational view of the signal segment  12  of  FIG. 6   a;    
         [0032]      FIG. 7   a  is a perspective representation of a signal segment  13 ;  
         [0033]      FIG. 7   b  is a side elevational view of the signal segment  13  of  FIG. 7   a;    
         [0034]      FIG. 8   a  is a terminal side view of an edge connector with the signal segment  11 ;  
         [0035]      FIG. 8   b  shows the contact pattern of the edge connector made according to  FIG. 8   a;    
         [0036]      FIG. 9   a  is a terminal side view of an edge connector with the signal segment  12 ;  
         [0037]      FIG. 9   b  shows the contact pattern of the edge connector made according to  FIG. 9   a;    
         [0038]      FIG. 10   a  is a terminal side view of an edge connector with the signal segment  13 , and  
         [0039]      FIG. 10   b  shows the contact pattern of the edge connector made according to  FIG. 10   a.   
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0040]      FIG. 1   a  shows an edge connector  1  that essentially consists of a metallic housing  3  and a connector insert  5  of an insulating material, wherein the shape of the connector insert on the mating side  7  defines the mating pattern and the opposite terminal side  8  contains the electric contacts.  
         [0041]     In  FIG. 1   b,  the metallic housing  3  with the terminal side  8  is illustrated separately of the connector insert  5  with its faceplate  6 .  
         [0042]      FIG. 2   a  shows another exploded view of an edge connector  1  comprising the metallic housing  3  and the connector insert  5 , wherein this figure also shows removed discoid segments  11  with pairs of electric contacts  15  embedded therein.  
         [0043]     According to the sectional representation shown in  FIG. 2   b,  the segments  11  are inserted into the interior of the housing  3  from the terminal side  8  until a limit stop  4  is reached. The connector insert  5  can be inserted from the mating side  7 .  
         [0044]     The invention proposes to non-positively insert the segments into the metallic housing adjacent to one another from the upper and lower sides such that they exert a certain pressure upon the narrow sides.  
         [0045]      FIG. 3  shows a detailed representation of the terminal side of the edge connector with segments  10 ,  11  inserted therein.  
         [0046]     Contacts  16  protruding from the segments  11  are also illustrated in this figure.  
         [0047]     Structures  9  are arranged on both side walls of the metallic housing  3  such that they are equidistantly spaced apart from one another and point into the housing interior.  
         [0048]     The signal segments  11  are respectively inserted into sections formed by two structures  9  while one respective ground segment  10  is inserted into the remaining space. Ground segment  10  is shorter than the signal segment  11  such that it can be inserted between the opposite structures  9 .  
         [0049]      FIG. 4  shows a ground segment  10 , in perspective representation in  FIG. 4   a  and in top plan view in  FIG. 4   b.    
         [0050]     The ground segment  10  comprises an insulating member  18  with a contact element  15  embedded therein, wherein two fork-shaped mating contacts  14  are provided on the mating side and ground contact sections  17  protrude from the side walls of the insulating member.  
         [0051]     When the ground segment is inserted, the ground contact sections  17  directly contact the structures  9  on the upper and lower side of the metallic housing  3 .  
         [0052]     Since no direct contacts need to be produced between the ground segments  10  and the mother board, the number of bores on the mother board required for transferring the measuring signals can be reduced.  
         [0053]      FIGS. 5, 6  and  7  show a few variations of signal segments  11 ,  12 ,  13 .  
         [0054]     The signal segments  11 ,  12 ,  13  respectively comprise two electric contacts  15  that are surrounded by an insulating member  18 , wherein two respective mating ends  14  form a tulip-shaped contact for contacting the strip conductors of a double-sided daughter board.  
         [0055]     Straight contacts  16  extending out of the opposite side of the insulating member are pressed or soldered onto the mother board.  
         [0056]     The contacts may be bent by 90° such that the straight connector shown also can be used as an angle connector.  
         [0057]     In the side view according to  FIG. 5   b,  the signal segment  11  has a contact  15  that is arranged centrally within the insulating member  18 —referred to the side walls thereof.  
         [0058]     The signal segments  12  in  FIG. 6   b  have eccentrically arranged contacts  16  on the terminal side, wherein the contacts end practically flush with one side wall of the insulating member  18 .  
         [0059]      FIG. 7   b  shows a signal segment  13 , in which at least half the material thickness of the contact  16  is arranged laterally outside the insulating member  18 .  
         [0060]      FIG. 8   a  shows the terminal side of an edge connector with the metallic housing  3 , in which the signal segments  11  and ground segments  10  are arranged in a row as described above. Two signal segments  11  and one ground segment  10  are alternately arranged adjacent to one another in this case.  
         [0061]     Two signal segments  11  are shown removed in the figure and arranged such that the contacts  16  are positioned in the first and in the third quarter—the so-called segment height—in one segment (S 1 ) and in the second and in the fourth quarter in the adjacent segment (S 2 ). With respect to the identical segments shown, this is achieved by simply turning an adjacent segment by 180° (in this respect, see also  FIG. 3 ).  
         [0062]      FIG. 8   b  shows an arrangement of bores on the circuit board that corresponds to the edge connector according to  FIG. 8   a.  Thus, with the present invention, the five rows that are required in conventional connectors and also include the ground contacts are reduced to four parallel rows  20 ,  22 ,  24 ,  26  of bores that are spaced apart from one another by 1.5 mm, wherein the bores of a row are spaced apart from one another by 2.25 mm.  
         [0063]     The rows  22  and  26  are laterally offset relative to the rows  20  and  24  by 0.75 mm.  
         [0064]     This is illustrated with reference to the individual bores  21  and  23  of the rows  20 ,  22 .  
         [0065]      FIG. 9   a  shows the terminal side of an edge connector made in accordance with the present invention with signal segments  12  and ground segments  10 .  
         [0066]     The very compact contact pattern shown in  FIG. 9   b  is achieved because the contacts  16  of the signal segments  12  end practically flush with the side wall of the insulating member  18  and the adjacently arranged segments are also turned by 180°.