Demand for high density packaging has led to the development of multi-wire cable having signal conductors, grounding conductors, and shielding arranged on very close centers. To do this, it has been necessary to utilize extremely fine and frequently fragile elements. For example, signal and conductor or drain wires may have diameters on the order of 0.003 to 0.009 inches. Shielding ground is typically provided by a wraparound conductive film on the order of 0.001 inch or fine braid with numbers of cables having such elements and characteristics combined together in ribbon form. These cables are made to have specific impedances relative to the types of signals required to be transmitted, and care must be taken to keep ground and signal spacings appropriate to avoid discontinuities with particular care taken in stripping such cable of the outer insulating and protective sheath, engaging the different conductors and mechanically and electrically interconnecting such conductors to signal, ground, and shielding circuits of either a connector or a circuit board or the like. Thin foil grounding and shielding conductors have proven to be most difficult to reliably terminate, by solder or mechanical means providing an electrical interconnection thereto. In certain instances, a fine drain or separate wire is used, being engaged along the length of the foil conductor to make such interconnection. As a result, termination of multi-wire cable, and particularly multi-wire coaxial cable, has proven to be time consuming, difficult, anticostly with numerous defects requiring expensive cable assemblies to be scrapped.
U.S. Pat. No. 4,929,195 granted May 29, 1990 and directed to a shielded connector, teaches the use of an electrically conductive body called a stopper that is applied to the shielding of a multi-wire cable. The stopper includes an outer groove and serves to mechanically and electrically connect the shielding of the cable to an outer shielding of a connector. This serves to protect against tensile forces applied to the cable and shield wire and further, to interconnect the shield wire to the outer metallic portions of the connector without the use of solder. U.S. Pat. No. 4,614,398 granted Sep. 30, 1986 is directed to a shielded cable terminal connection wherein a resilient bushing of conductive material is inserted between the shield portions of a coaxial cable and the inner surface of a backshell housing that is crimped down against the resilient bushing to provide a mechanical and electrical connection to coaxial cable and a connector. U.S. Pat. No. 3,744,128 granted Jul. 10, 1973 teaches the use of making shielded connector assemblies utilizing an electrically conductive potting material to provide a conductive path between cable shield and the metallic housing of a connector. Also of background is U.S. Pat. No. 4,828,512 granted May 9, 1989 and drawn to a connector for flat electrical cable employing an elastomeric material that is conductive to enclose the connection for EMI/EMP shielding. Of these prior art teachings, only U.S. Pat. No. '512 appears to deal with small or very fine conductors, and such teaching is confined to a particular shielded flat flex cable employing a low durometer elastomeric material and small conductive balls to effect an interconnection of cables.
Accordingly, it is an object of the present invention to provide an electrical connection of multi-wire cables and method that facilitates a common electrical grounding and mechanical holding of the fragile parts of such cable. It is still a further object to provide an electrical connection and method of manufacture facilitating the interconnection of fine foil, ground and shielding conductors of multi-wire cable. It is a further object to provide an improved electrical connection and method of manufacture of a common grounding element having features facilitating mounting and retention of cables relative to a further connector or circuit. It is a final object of the invention to provide a novel housing construction in conjunction with a casting or molding of plastic material into such housing around the shielding of fine multi-wire cable.