Conductors carrying high frequency signals and currents are subject to interference and cross talk when placed in close proximity to other conductors carrying high frequency signals and currents. This interference and cross talk can result in signal degradation and errors in signal reception. Coaxial and shielded cables are available to carry signals from a transmission point to a reception point, and reduce the likelihood that the signal carried in one shielded or coaxial cable will interfere with the signal carried by another shielded or coaxial cable in close proximity. However, at points of connection, the shielding is often lost allowing interference and crosstalk between signals. The use of individual shielded wires and cables is not desirable at points of connections due to the need for making a large number of connections in a very small space. In these circumstances, two-part high- speed connectors containing multiple shielded conductive paths are used.

U. S. Patent No. 6,146,202 entitled"High Speed Connector Apparatus" discloses an illustrative shielded two-part high-speed connector comprising a socket connector and a header connector. The illustrative socket connector includes a plurality of connector modules. Each connector module includes an insulative housing encasing a plurality of longitudinally extending, vertically spaced signal contacts arranged in a column. Each insulative housing is formed to include a plurality of laterally extending, vertically spaced openings which are interleaved with the plurality of longitudinally extending, vertically spaced signal contacts. The socket connector further includes a plurality of vertical shields extending along the first sides of the plurality of connector modules, and a plurality of horizontal shields extending through the laterally extending, vertically spaced openings in the plurality of connector modules to form a coaxial shield around each signal contact.

According to the present invention, an illustrative connector includes a plurality of connector modules. Each connector module includes an insulative housing encasing a plurality of longitudinally extending, laterally spaced signal

contacts arranged in a row. Each insulative housing is formed to include a plurality of vertically extending, laterally spaced openings which are interleaved with the plurality of longitudinally extending, laterally spaced signal contacts. The connector further includes a plurality of shields. Each shield has a vertically extending flange portion for insertion into a vertically extending opening in the insulative housing and a laterally extending flange portion extending along and adjacent to a signal contact in the insulative housing. The vertically and laterally extending flange portions are configured to form a coaxial shield around each signal contact. According to one illustrative embodiment, the laterally extending flange portion extends along and above an adjacent signal contact in the insulative housing. According to still another illustrative embodiment, the insulative housings with contacts and shields assembled therein are configured for insertion into laterally extending, vertically spaced slots in a connector housing.

According to a further illustrative embodiment, an illustrative connector includes a plurality of longitudinally extending, laterally spaced signal contacts arranged in a row. Each signal contact includes a forwardly extending contact portion configured to engage a corresponding contact in a mating connector, an intermediate portion and a rearwardly extending tail portion. An insulative housing encases the intermediate portions of the signal contacts. The insulative housing includes laterally spaced, vertically extending slots between the contact intermediate portions. A shield is provided for each signal contact. Each shield has a vertically extending flange portion for insertion into a slot in the insulative housing and an upper laterally extending flange portion extending along and above the intermediate portion of an adjacent signal contact. The vertically and laterally extending flange portions form a coaxial shield around each signal contact. The insulative housings with contacts and shields assembled therein form connector modules which are configured for insertion into a connector housing.

According to a further illustrative embodiment, an illustrative connector includes a plurality of horizontally spaced signal contacts arranged in a row. Each signal contact includes a forwardly extending contact portion configured to engage a corresponding contact in a mating connector, an intermediate portion and a rearwardly extending tail portion. An insulative housing encases the intermediate

portions of the signal contacts. The insulative housing includes horizontally spaced, vertically extending slots between the contact intermediate portions. A shield is provided for each signal contact. Each shield has a vertical flange portion for insertion into a slot in the insulative housing and an upper horizontal flange portion extending along and above the intermediate portion of an adjacent signal contact. The vertical and horizontal flange portions form a coaxial shield around each signal contact. The insulative housings with contacts and shields assembled therein form connector modules which are configured for insertion into a connector housing.

Alternatively, the connector modules may be pressed into single row insulators with a press-fit connection, with one single row insulator for each connector module. The assembled connector modules may then be stacked to a desired height, and inserted into a housing. The housing captures the assembled connector modules, and provides insulation and shielding around the stacked assembly.

Additional features of the present invention will become apparent to those skilled in the art upon a consideration of the following detailed description of the preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS The detailed description particularly refers to the accompanying figures in which: Fig. 1 is a perspective view showing a plurality of signal contacts arranged in a horizontal row, each contact having a forwardly extending contact portion configured to engage a corresponding contact in a mating connector, an intermediate portion and a rearwardly extending tail portion; Fig. 2 is a perspective view showing the contact intermediate portions encased in an insulative housing, the insulative housing having horizontally spaced, vertical slots between the contact intermediate portions; Fig. 3 is a perspective view showing two shields-one shield per contact, each shield having a vertical flange portion for insertion into a vertically extending slot in the insulative housing and an upper horizontal portion extending along and above the intermediate portion of the adjacent contact;

Fig. 4 is a perspective view showing plastic overmolds formed on the upper horizontal portions of the shields adjacent to the front end; Fig. 5 is a perspective view showing a first set of shields vertically aligned with first and third slots in the insulative housing; Fig. 6 is a perspective view showing the first set of shields pressed into the first and third slots in the insulative housing with a press-fit connection ; Fig. 7 is a perspective view showing a second set of shields pressed into second and fourth slots in the insulative housing with a press-fit connection to form a connector module or wafer; Fig. 8 is a perspective view showing a front cap having horizontally extending slots for receiving the connector modules; Fig. 9 is a perspective view showing a connector module aligned with a horizontally extending slot in a front cap; Fig. 10 is a perspective view showing the connector module pressed fully into the front cap with a press-fit connection ; Fig. 11 is a perspective view showing a fully assembled connector including eight rows of connector modules arranged in vertical column, each row of connector modules having four contacts arranged in a horizontal row; and Fig. 12 is a partial sectional view of the Fig. 11 connector showing vertical and horizontal shielding portions of shields forming a virtual coaxial box around each signal contact.

DETAILED DESCRIPTION OF THE DRAWINGS Fig. 1 shows four horizontally spaced, signal contacts 30 arranged in a row. The contacts 30 are arranged in rows instead of columns. The horizontal spacing between the adjacent contacts 30 is 2 millimeters. Each contact 30 includes a forwardly extending contact portion 32 configured to engage a corresponding signal pin of a mating header connector (not shown), an intermediate portion 34 and a rearwardly extending tail portion 36. Each contact portion 32 includes a pair of opposed cantilevered spring arms 38 into which a signal pin of a mating header connector is inserted when a socket connector 20 and a header connector are mated.

The tail portions 36 are soldered to cable wires. Preferably, the contacts 30 are

stamped out of a strip of suitable conductive material, and are manufactured reel to reel. The strip can be cut to any length to create variable connector lengths (e. g., eight signal contacts to a row instead of four to a row).

As best shown in Fig. 2, an insulative housing 50 encases the contact intermediate portions 34. The insulative housing 50 includes four horizontally spaced, vertically extending slots 52 arranged between the contact intermediate portions 34 for receiving four shields 60-one shield 60 for each contact 30. The housing 50 (sometimes referred to herein as the"contact overmold") is formed by overmolding a plastic insulator over the contact intermediate portions 34. The overmolding process can be also performed reel to reel as the contacts 30 are fed on a strip. The vertical slots 52 are formed simultaneously between adjacent contacts 20 as the insulative housing 50 is overmolded over the contacts 30. A jog is provided in the tail portion 36 to center the tail portion 26 in the plastic overmold 50 during the overmolding operation.

Fig. 3 shows two horizontally spaced apart shields 60. The horizontal spacing between the adjacent shields 60 is 4 millimeters. Preferably, the shields 60 are stamped out of a strip of suitable conductive material, and are manufactured reel to reel. The 4 millimeter spacing between the shields 60 makes it possible to manufacture the shields 60 reel to reel. Each shield 60 includes a vertical flange portion 62 for insertion into a slot 52 in the insulative housing 50, and an upper horizontal portion 64 extending along and above the intermediate portion 34 of the adjacent contact 30. The vertical flange portion 62 of each shield 60 includes a forwardly extending vertical shield portion 66 configured to be located next to a forwardly extending contact portion 32 of an adjacent contact 30. The forwardly extending vertical shield portion 66 is configured to engage a ground pin of a mating header connector (not shown) to couple the shield 60 to ground. The upper horizontal portion 64 of each shield 60 includes a forwardly extending horizontal shield portion 68 configured to be located above a forwardly extending contact portion 32 of an adjacent contact 30. As shown in Fig. 12, the vertical flange portion 62 provides shielding between adjacent columns of contacts 30. The upper horizontal portion 64 provides shielding between adjacent rows of contacts 30.

As shown in Fig. 4, the forwardly extending horizontal shield portion 68 of each shield 60 includes an insulative housing 70 surrounding the forwardly extending horizontal shield portion 68. The insulative housing 70 (sometimes referred to herein as the"shield overmold") may be formed by overmolding a plastic insulator over the forwardly extending horizontal shield portion 68 of the upper horizontal portion 64. The overmolding process can also be performed reel to reel as the shields 60 are fed on a strip. The plastic overmold 70 prevents the vertically compliant spring arms 38 from accidently contacting the forwardly extending horizontal shield portion 68 when a signal pin of the header connector (not shown) is inserted between the vertically compliant spring arms 38 as the socket connector 20 is mated with a header connector (not shown).

Fig. 5 shows a first set of shields 60 vertically aligned with first and third slots 52 in the contact overmold 50 having contacts 30 embedded therein. Fig. 6 shows the first set of shields 60 pressed into the first and third slots 52 in the plastic overmold 50 with a press-fit connection. Fig. 7 shows a second set of shields 60 pressed into second and fourth slots 52 in the plastic overmold 50 with a press-fit connection to form a connector module 80 (also referred to as a wafer). Thus, the contacts 30 are formed on strips with the horizontal spacing between the successive contacts 30 a first distance (2 millimeters). The shields 60, on the other hand, are formed on strips with the horizontal spacing between the successive shields 60 a second distance (4 millimeters) equal to twice the first distance (2 millimeters) such that a first set of shields 60 may be inserted into every other slot 52 while disposed on a first strip and then a second set of shields 60 may be inserted into the empty slots 52 between the first set of shields 60 while disposed on a second strip.

Fig. 8 shows a front cap 90 (also referred to as socket or connector housing) having horizontally extending slots 92 configured for receiving the connector modules 80. Fig. 9 shows a connector module or a wafer 80 aligned with a horizontally extending slot 92 in the front cap 90. Fig. 10 shows the connector module 80 pressed fully into the front cap 90 with a press-fit connection. Fig. 11 shows a fully assembled socket connector 20 including eight rows of connector modules 80 arranged in vertical column, with each row having four contacts 30 arranged in a horizontal row. Fig. 12 is a partial sectional view of the socket

connector 20 showing the vertical and horizontal shielding portions 62,64 of the shields 60 forming a virtual coaxial box around each signal contact 30. Coaxial shielding of each signal contact 30 allows transmission of high frequency signals at the points of connection with minimum interference and cross talk.

The 8x4 contacts 30 are aligned with 8x4 pin insertion windows 94 in the front cap 90 when the connector modules 80 are assembled in the front cap 90.

The pin insertion windows 94 guide the signal pins of a header connector (not shown) when the socket connector 20 is mated with a header connector. As previously indicated, the signal pins of the header connector are received by the spring arms 38 of the contacts 30 of the socket connector 20. The number of rows and columns in the socket connector 20 can be chosen freely and independently of each other. For example, one may design a socket connector 20 having 16 rows, with 8 contacts per row, instead of 8 rows, with 4 contacts per row. The socket connector 20 of the present invention is particularly suited for high speed cable application.

Alternatively, a connector module 80 may be pressed into a single row insulator (not shown) with a press-fit connection (also referred to as a single row concept). The assembled connector modules 80 may then be stacked to a desired height (e. g., 16 rows or 8 rows), and inserted in a perimetral housing (not shown).

The housing holds the assembled connector modules 80 in place, and provides insulation and shielding around the stacked connector modules 80.

Illustratively, the materials used for the socket connector 20 are as follows: a) signal contacts 30: copper alloy, UNS C70250,0.2% offset, 95-120 ksi yield, 100-125ksi tensile b) signal contact overmold 50: 30% glass-filled LCP, Dupont Zenite 6130L c) shield 60: phosphor bronze, 510 spring temper d) shield overmold 70: 30% glass-filled LCP, Dupont Zenite 6330 e) front cap 90: 30% glass-filled LCP, Dupont Zenite 3226L Although the present invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the present invention as described above.