Abstract:
An electrical connector comprising a pair of elongated bodies, each having a facing ramp, the ramp having an notch, each having a rotatable torsion bar conductor with a tip located in the notch, the end of a tip spaced above the ramp such that when the two bodies are mated, the tips engage the ramp of the other connector and rotate against a torsional restoring force, and when fully mated, the two ramps abut each other, notches aligned, with the respective tips of the torsion bars engaging the torsion bar of the other body in the aligned notches.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional application of U.S. patent application Ser. No. 13/328,930, filed Dec. 16, 2011, which is a divisional application of U.S. patent application Ser. No. 13/052,831, filed Mar. 21, 2011, now U.S. Pat. No. 8,079,848; which application is a divisional application of U.S. patent application Ser. No. 12/953,171, filed Nov. 23, 2010, now U.S. Pat. No. 7,909,615; which application is a divisional application of U.S. patent application Ser. No. 11/123,863, filed May 6, 2005, now U.S. Pat. No. 7,845,986; which application claimed priority from, and incorporated by reference in its entirety and for all purposes, U.S. Provisional Application No. 60/569,311, filed May 6, 2004, entitled: “Torsionally-Induced Contact-Force Conductors for Electronic Connectors” and U.S. Provisional Application No. 60/580,873, filed Jun. 17, 2004, entitled: “Torsionally-Induced Contact-Force Conductors for Electronic Connectors II.” 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to the field of electro-mechanical interconnection devices and systems. 
       BACKGROUND 
       [0003]    Electrical interconnection systems commonly incorporate vias, or plated through holes, to make electromechanical connections between electrical components and printed circuit boards. However, via can cause significant harm to signal integrity.  FIG. 1  illustrates a prior-art electrical connector system in which the electrical connector  101  attaches to a printed circuit board  102 , which contains multiple layers  103 . A conductive pins  104  are inserted into a plated through holes  105 , which consists of a hole  106 , drilled through the printed circuit board, and an annular pad  107 —both of which are plated with a conductive material. The plated through holes make electrical connections between the conductive pins  104  and signal traces  108  that may be located one or more layers within the printed circuit board. The plated through holes  105  and the annular pads  107  may both act capacitively and harm signal integrity. 
         [0004]    Often, electromechanical interconnection devices incorporate resilient or spring structures to maintain contact force at the point of connection between electrical components. Different spring conductors may be compared for their ability to produce deflection for the same force applied to the resilient structures used to create the spring effect. Spring conductor structures are generally designed to: (1) establish and maintain sufficient mechanical contact force for the intended application; (2) require the smallest amount of deflection to attain this contact force; (3) have little or no permanent deformation; and (4) require the smallest volume possible. 
         [0005]    To address each of these attributes, spring structures are often complicated in nature and difficult to manufacture, particularly when the structures are very small. Complexity of resilient interconnection structures typically increases when electrical components are disposed at various angles to each other, often necessitating curved or irregularly shaped interconnection structures. Bends and twists in conductive elements can degrade signal integrity and increase cost. 
         [0006]      FIG. 2  illustrates the prior art of an edge card connector mounted on a mother board. The connector accepts a vertically oriented plug-in card  201  that bends the conductors  202  to produce contact force and establish electrical continuity. The conductors  202  are cantilever beams whose fixed ends  203  are attached to the horizontally oriented substrate  204 . The contact forces, which are at the free ends  205  of the cantilever beams, bend the cantilever beams. Cantilever beams do not store energy in a uniform manner throughout their length. The greatest stresses or stored energy per unit volume is at the fixed end  203  of the cantilever beam and are at their lowest at the free ends  205  where the electrical contacts exist. The conductors  202  could be made smaller if they were designed to store energy more uniformly throughout the conductors&#39; volume. 
         [0007]      FIG. 3  illustrates prior art wherein cantilever-beam conductors  301  are disposed in an electrical connector at an angle to electrical contact pads  302  on a printed circuit board  303 , which is perpendicular to printed circuit board  303  (not pictured at right). The ends or electrical contacts  304  of the cantilever-beam conductors  301  bend to produce contact force between the cantilever-beam conductors  301  and the substrate&#39;s electrical contact pad  302 . 
         [0008]      FIG. 4  illustrates another view of the prior art connector in  FIG. 3 , illustrating the movement of the cantilever-beam conductors, which requires air voids or gaps  405  within the normally uniform dielectric material forming the transmission line structure. The gaps or air voids  405  constitutes a physical discontinuity reducing the signal integrity of the interconnection. The air voids  405  can be compensated for by adjusting the properties and shape of the other connector parts, but this increases the complexity and cost of the connector. In addition, in  FIG. 4 , the conductors  301  must bend sufficiently within the air voids  405  to attain the configuration necessary for the correct characteristic or differential impedance. Because the connector&#39;s electrical contacts  304  may not mate with the electrical contact pads  302  in a consistent manner, the cantilever-beam conductor&#39;s movement may alter the spatial and dimensional requirements necessary to provide the correct characteristic or differential impedance and this alteration may reduce signal integrity. 
         [0009]      FIG. 5  illustrates a typical prior art torsion bar conductor. A torsion bar conductor  501  with head  505  is inserted into a two-tined receptacle  502 , which exerts a twisting force on the head  505 , which twists the torsion bar conductor  501 . A high speed signal will encounter sharp corners  504  on the torsion bar conductor  501  creating signal reflections. The tines  503  on receptacle  502  are capacitive stubs. Both the signal reflections and the capacitive stubs reduce signal integrity. 
         [0010]      FIG. 6  illustrates a prior art cantilever beam commonly used to create force in electrical interconnection systems.  FIG. 6  illustrates a round wire beam  601  of length L, radius r and modulus of elasticity E. It has a fixed section  602  and has a force  603 , F.sub.C, placed at the unconstrained tip section  604  (which is a moment arm). The force is in a direction perpendicular to the cantilever round wire beam&#39;s axis. 
         [0011]    Despite these and other efforts in the art, further improvement in cost and performance is possible by simplifying design and lowering manufacturing cost. There is opportunity and need for improvements which will address the gap between present options and future requirements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: 
           [0013]      FIG. 1  illustrates the prior art of electronic interconnect for a printed circuit board assembly; 
           [0014]      FIG. 2  illustrates the prior art of an edge card connector; 
           [0015]      FIG. 3  illustrates the prior art of a canted cantilever-beam conductors in electrical contact with a substrate&#39;s electrical contact pads; 
           [0016]      FIG. 4  illustrates an example of a cross section of the electronic connector in  FIG. 3 ; 
           [0017]      FIG. 5  illustrates the prior art of a torsion bar conductor inserted into a two-tined receptacle; 
           [0018]      FIG. 6  illustrates a section of a cantilever round wire beam spring conductor; 
           [0019]      FIG. 7  illustrates an embodiment with a fixed section, a torsion section and a tip section (that forms a moment arm); 
           [0020]      FIG. 8  illustrates an embodiment with a torsion bar section and two tip sections (that form moment arms) which twist about the torsion section; 
           [0021]      FIG. 9  illustrates an embodiment identical to  FIG. 8  except that the tip sections are inclined in alternating directions; 
           [0022]      FIGS. 10   a  and  10   b  illustrate an embodiment showing a torsion bar conductor whose moment arm protrudes from the channel than others in the surrounding structure; 
           [0023]      FIG. 11  illustrates an isometric view of an embodiment which is a torsion bar conductor at rest whose cylindrical axes are all in the same plane; 
           [0024]      FIG. 12  illustrates orthographic top, front and right views of the torsion bar conductor in  FIG. 11 ; 
           [0025]      FIG. 13  illustrates an embodiment in which the torsion bar conductors shown in  FIG. 11  are fitted into channels in a dielectric material layer; 
           [0026]      FIG. 14  illustrates an embodiment in which torsion bar conductors are an integral part of a ground plane; 
           [0027]      FIG. 15  illustrates the torsion bar conductor ground plane in  FIG. 14  seated in a connector body; 
           [0028]      FIG. 16A  illustrates a view of the moment arm of the torsion bar conductor perpendicular to its axis; 
           [0029]      FIG. 16B  illustrates a right hand view of the moment arm in  FIG. 16A  in the axial direction; 
           [0030]      FIG. 17  illustrates a perspective view of the connector body in  FIG. 15  with conductive coating on the planar surface and the cylindrical channels; 
           [0031]      FIG. 18  illustrates a side view of an embodiment, an electrical connector whose connector body includes dielectric layers that capture two torsion bar conductor ground planes above and below a row of individual torsion bar conductors; 
           [0032]      FIG. 19  illustrates a cross section of the embodiment in  FIG. 18 ; 
           [0033]      FIG. 20  illustrates an embodiment wherein printed circuit boards are connected utilizing torsion bar elements, and the printed circuit boards are disposed at 180 degrees to each other; 
           [0034]      FIG. 21  illustrates the same side view as in  FIG. 18  except that the electrical contact rows are arrayed in a stair step configuration; 
           [0035]      FIG. 22  illustrates the interconnect face of the electrical connector in  FIG. 19  showing an array of torsion bar conductors&#39; electrical contacts; 
           [0036]      FIG. 23A  illustrates an enlarged view of the electrical contact in  FIG. 22  when it is in the unmated condition; 
           [0037]      FIG. 23B  illustrates an enlarged view of the electrical contact in  FIG. 23A  when it is in the fully mated condition; 
           [0038]      FIG. 24  illustrates an embodiment in which a torsion bar conductor incorporates a bend in its central portion; 
           [0039]      FIG. 25  illustrates an embodiment in which a torsion bar conductor&#39;s axes are bent out of plane; 
           [0040]      FIG. 26  illustrates orthographic top, front and right views of the torsion bar conductor in  FIG. 25 ; 
           [0041]      FIG. 27  illustrates an embodiment with stair step rows of torsion bar conductor electrical contacts; 
           [0042]      FIG. 28  illustrates orthographic front, right and bottom views of  FIG. 27 ; 
           [0043]      FIG. 29  illustrates a top isometric view of the embodiment in  FIG. 27  with a portion of the top insulating layer removed to show the torsion bar conductors; 
           [0044]      FIG. 30  illustrates an embodiment of the invention in  FIG. 29  except with air cavities in the dielectric layer underneath the conductors; 
           [0045]      FIG. 31  illustrates the torsion bar conductor in  FIG. 30  with the surfaces of the cavities conductively coated and insulated spacers supporting the conductors; 
           [0046]      FIG. 32  illustrates the use of torsion bar conductors that connect printed circuit boards oriented 180 degrees to each other and whose electrical contact pads are opposite each other; 
           [0047]      FIG. 33  illustrates the torsion bar conductors that are an extension of signal traces in a flexible circuit or of wires in a cable; 
           [0048]      FIG. 34  illustrates the torsion bar conductors bent at an angle so that the contact wipe is in the direction of the signal traces on the printed circuit board; 
           [0049]      FIG. 35  illustrates the curved torsion bar conductors in closely fitted channels; 
           [0050]      FIG. 36  illustrates the torsion bar conductors embedded inside a printed circuit board such as a backplane with a portion of the top PCB layer removed to show the torsion bar conductors; 
           [0051]      FIG. 37  illustrates a cross section of  FIG. 36  showing the opening surrounding the moment arms of the torsion bar conductors used as signal or power buses; 
           [0052]      FIG. 38  illustrates a single torsion bar conductor with several electrical contact points; 
           [0053]      FIG. 39  illustrates the multiple-contact torsion bar conductors used in a bus configuration within a printed circuit board; 
           [0054]      FIG. 40  illustrates the bus configuration in  FIG. 39  with the top PCB layer removed to show the multiple-contact torsion bar conductors; 
           [0055]      FIG. 41  illustrates an embodiment showing how a push pin is combined with the torsion bar conductors with the left PCB mated and the bottom PCB in an unmated condition; 
           [0056]      FIG. 42  illustrates an enlarged view of the pin and torsion bar conductor&#39;s moment arm in  FIG. 41  in its mated condition; 
           [0057]      FIG. 43  illustrates an exploded view of the torsion bar conductors used in a coaxial transmission line; 
           [0058]      FIG. 44  illustrates the electrical connector in  FIG. 43  in a perspective view from the bottom; 
           [0059]      FIG. 45  illustrates an isometric view of an embodiment, the torsion bar conductors in a coaxial transmission line wherein the bottom housing&#39;s material is conductive; 
           [0060]      FIG. 46  illustrates a bottom view of the connector in  FIG. 45  showing the conductive material in the bottom housing; 
           [0061]      FIG. 47  illustrates an embodiment, a torsion bar conductor shaped for use in an interposer connector wherein the two electrical contact points rotate through the same plane; 
           [0062]      FIG. 48  illustrates a top isometric view of an embodiment, an electrical interposer connector that uses the torsion bar conductor shown in  FIG. 47 ; 
           [0063]      FIG. 49  illustrates the electrical interposer in  FIG. 48  with the top housing removed; 
           [0064]      FIG. 50  illustrates the electrical interposer in  FIG. 48 , an embodiment, except with rows of torsion bar conductors in a stair step configuration that mate with electrical contact pads in a stair step configuration on a printed circuit board; 
           [0065]      FIG. 51  is an embodiment of the torsion bar conductor shown in  FIG. 47 ; 
           [0066]      FIG. 52A  illustrates an embodiment, torsion bar conductors in a circular conductor that mates axially; 
           [0067]      FIG. 52B  illustrates the position and relationship of the torsion bar conductors in  FIG. 52A  without the connector housings; 
           [0068]      FIG. 53A  illustrates an embodiment, torsion bar conductors wherein the plug and receptacle housings (not shown) in a circular connector have moved together axially but have not been rotated with respect to each other; 
           [0069]      FIG. 53B  illustrates a view looking down the axes of the torsion bar conductors in  FIG. 53A ; 
           [0070]      FIG. 54A  illustrates torsion bar conductors after the plug and receptacle housings (not shown) in a mated circular connector have moved together axially and have been rotated with respect to each other; 
           [0071]      FIG. 54B  illustrates an end view looking down the axes of the conductors in  FIG. 54A ; 
           [0072]      FIG. 55A  illustrates an embodiment, two electrical connector assemblies, before mating occurs, showing torsion bar conductors inside connector bodies; 
           [0073]      FIG. 55B  illustrates the two electrical connector assemblies in  FIG. 55A  with the right connector body removed; 
           [0074]      FIG. 56A  illustrates the two electrical connector assemblies in  FIG. 55A  partially mated; 
           [0075]      FIG. 56B  illustrates the two electrical connector assemblies in  FIG. 56A  with the right connector body removed; 
           [0076]      FIG. 57A  illustrates the two electrical connector assemblies in  FIG. 55A  fully mated; 
           [0077]      FIG. 57B  illustrates the two electrical connector assemblies in  FIG. 57A  with the right connector body removed; and 
           [0078]      FIG. 58  illustrates an embodiment, a rectangular array of the electrical connector assemblies from  FIG. 55A . 
       
    
    
     DETAILED DESCRIPTION 
       [0079]    In the following description and in the accompanying drawings, specific terminology and drawing symbols are set forth to provide a thorough understanding of the present invention. In some instances, the terminology and symbols may imply specific details that are not required to practice the invention. For example, the interconnection between circuit elements or circuit blocks may be shown or described as multi-conductor or single conductor signal lines. Each of the multi-conductor signal lines may alternatively be single-conductor signal lines, and each of the single-conductor signal lines may alternatively be multi-conductor signal lines. Signals and signaling paths shown or described as being single-ended may also be differential signal pairs, and vice-versa. In the description of any embodiment, when the term electrical component is used, it may include but not be limited to printed circuit boards and other electrical circuit structures including but not limited to printed wiring boards, flexible circuits with layers of metal and dielectric, ceramic or silicon substrates, hybrid circuits, integrated circuits, integrated circuit packages, or a combination of them. Any of the aforementioned items may be substituted for any other aforementioned item. Printed circuit boards may be shown or described at a 90 or 180 degree angle to each other, but unless specifically stated otherwise can be at any other angle. 
         [0080]    One or more figures may show two conductors that comprise a differential signal pair. In all such cases, the conductors may be any conductive material such as metal coated plastics, metal, conductive elastomers or conductive plastics. The conductors shown may also be single-ended conductors, single conductors in microwave and stripline geometries, and coaxial conductors. In figures showing a cross sectioned view of the invention, the presence of the cross section implies that there are additional conductors behind and/or in front of the visible conductors. Also, although a conductor may appear to be at a specific angle with respect to a printed circuit board&#39;s surface, it may be at any angle with respect to a printed circuit board&#39;s surface. The term “dielectric” may be interchanged with the term “insulative”. 
         [0081]    Embodiments of the invention disclosed herein include electrical interconnection devices and systems having beam-shaped torsion bar conductors with a moment arm at one end or moment arms at each end. The torsion bar conductor creates contact force stored by twisting a torsion section of the device. In these embodiments, torsion structures replace springs, cantilever beams, or other resilient structures to create contact force and store energy. Torsion systems tend to distribute stress more uniformly and efficiently than many other spring-force systems. This efficiency makes it possible to reduce the size of a connection structure by incorporating torsion elements. Torsion bar conductors can also mate with other torsion bar conductors. 
         [0082]    In addition, embodiments of the invention disclosed herein include structures and methods for making three dimensional interconnections between electrical components with electrical contacts are arrayed on the connector&#39;s stair step surfaces and corresponding electrical contacts on stair step surfaces of electrical components to be mated, such as printed circuit boards. Stair step printed circuit boards shown or described herein may be implemented, for example, as described in U.S. patent application Ser. No. 10/990,280 (“Stair Step Printed Circuit Board Structures for High Speed Signal Transmissions”), filed Nov. 15, 2004, which is incorporated herein by reference. Stair step connections shown or described herein may be implemented, for example, as described in U.S. patent application Ser. No. 11/055,579 (“High Speed, Direct Path, Stair-Step Electronic Connectors with Improved Signal Integrity Characteristics and Methods for Their Manufacture”), filed Feb. 9, 2005, which is incorporated herein by reference. Redundant contact structures shown or described herein may be implemented, for example, as described in U.S. patent application Ser. No. 11/093,266 (“Electrical Interconnection Devices Incorporating Redundant Contact Points for Reduction of Capacitive Stubs and Improved Signal Integrity”) filed Mar. 28, 2005, which is incorporated herein by reference. 
         [0083]      FIG. 7  illustrates a torsion bar conductive element  701  that may have the same length, radius and modulus of elasticity as the conductive element described above in reference to  FIG. 6 . The torsion bar conductive element  701  has a fixed end  702 , and a torsion section  707  attached to a tip section  703 . The tip section  703  projects away from (i.e., is at a nonzero angle with respect to) the longitudinal axis of the torsion section  707  (perpendicular in the particular example shown) to form a moment arm. A restraining structure (not shown in  FIG. 7 ) can restrain or otherwise secure the fixed section  702  of the torsion bar  707  so that the torsion bar may twist about the longitudinal axis. A channel (e.g., a hole in a connector body or groove on a surface of the connector body, not shown in  FIG. 7 ) may be provided to maintain the orientation of the longitudinal axis of the torsion section while the torsion section is twisted. 
         [0084]    In general, the forces produced by each spring conductor are set equal to each other. In other words, F.sub.c is set equal to F.sub.t, where F.sub.c=loading force at tip of cantilever round wire beam  601  and F.sub.t=loading force at tip of moment arm on torsion bar conductor  701 . The cross sections perpendicular to the axes in  FIGS. 6 and 7  are shown as being round, but they may be square, rectangular or some other shape as long as the shape chosen and its dimensions are the same in each figure. Values E, r, L are equal in each type of spring conductor. For this example, the length of the moment arm equals 1.27 mm (0.05 inches). Poisson&#39;s ratio nu is set equal to 0.3 for both spring conductors, which is a common value for spring materials. Under these conditions it can be shown that the deflection d.sub.c of the cantilever round wire beam spring  601  is several times the deflection d.sub.t of the torsion bar conductor  701 . Thus the torsion bar conductor  701  tends to be more efficient at producing force within a fixed volume than the cantilever round wire beam  601  and may be volumetrically smaller. 
         [0085]      FIG. 7  illustrates an embodiment in which the torsion bar conductive element has a tip section  703  at one end, the tip section having a bend  704  that projects the tip section  703  away from the axis of the torsion section to form a moment arm, a torsion section  707  that is shown as straight but may be a curved (e.g. having one or more bends), and a fixed section  702  that may be conductively attached to conductive entities such as wires or signal traces in circuit structures not pictured at left. When a conductive surface, in this case electrical contact pad  708 , is forced in contact with the tip section  703 , a torsion force  705  is produced to rotate the tip section and twist the torsion section  707  in the direction shown at  706 . As mentioned, the torsion bar conductor  701  can be made volumetrically smaller than the cantilever round wire beam  601  but have the same electrical contact force when electrically mated. Yet another potential advantage is that the torsion bars  707  tend not to deviate substantially during electrical mating so that when the torsion bar conductor  701  is an element of a transmission line, the transmission line&#39;s characteristic impedance is also substantially unchanged. Yet another potential advantage is that the torsion bar conductor  701  can be fabricated from drawn wire whose diameter can be closely held to a very small tolerance so that the characteristic or differential impedance and the contact force remain within a smaller value range. Together or individually, these potential advantages may improve high frequency signal integrity. It should be noted that, while the moment arm is formed by a bend  704  in the tip section  703  in the embodiment of  FIG. 7 , the moment arm may be formed by any projection of the conductive element (or a member connected thereto) away from the longitudinal axis of the conductive element  702 . For example, a cam or flat member may be formed integrally with or secured to the conductive element to form a projection away from the longitudinal axis, thereby forming the moment arm. 
         [0086]    Another potential advantage of using a torsion bar conductor  701  for producing contact force in an electrical connector is ease of manufacturing. The torsion bar conductor can be shaped easily in a four slide bending tool, progressive die or other manufacturing method and placed on a holding reel for later assembly into connector housings. 
         [0087]      FIG. 8  illustrates an embodiment in which an electrical interconnection device  800  includes a conductive element  801  composed of a torsion section  804  and two tip sections  802 ,  803  set at an angle to the torsion section  804 . The tip sections  802 ,  803  twist around the axis of the resilient, torsion section  804 . The tip sections  802 ,  803  are disposed at an angle to the conductive pads  807 , and to the torsion section  804 , such that as electrical components  808  are moved toward torsion connector  801 , the tip sections  802 ,  803  rotate in opposite directions. The tip sections are moment arms and the direction of the moments are illustrated by the arrows  805  and  806 . The extreme ends of the moment arms  802 ,  803  act as electrical contacts. When the electrical contact areas  807  on electrical components  808  are moved toward the tip sections  802   803  of the torsion bar conductors  801 , an electrical interconnection is created. The torsion bar conductors  801  can be canted at various angles with respect to electrical components  808 . Insulating structures with closely conforming channels, not shown in  FIG. 8 , surround the torsion section  804  of the torsion bar conductor  801 , allowing the torsion section  804  to rotate but preventing the torsion section from buckling or having its axis substantially deviate from its rest position. Restraints within assembled parts of the electrical interconnection device  800  can hold the moment arms  802  and  803  in a pre-twisted condition before electrical mating has occurred. This creates a predetermined residual stress within the torsion bar conductors  801  when the electrical interconnection device is not mated with another electronic component. As a result of this predetermined residual stress, an adequate contact force can be reached quickly as soon as the electrical connector begins to mate and the moment arm lifts off a restraining wall. This reduces the space required to bring the moment arm into a position where adequate contact force is achieved. Two torsion bar conductors placed side by side may be a differential pair. 
         [0088]      FIG. 9  illustrates an embodiment of the electrical interconnection device in  FIG. 8 , in which a fixed section  901  of each of the torsion bars  902  are secured to closely conforming channels within a connector body (not shown) to prevent the torsion bar conductors  903  from freely rotating. The tip sections  904  that are adjacent to each other are inclined in opposite directions so that the sum total of their moments  905  tend to reduce the forces that may twist the body of electrical interconnection device  900  out of alignment with the electrical contact pads  906  or twist the body into an undesired shape. 
         [0089]      FIGS. 10A ,  10 B shows an embodiment of a torsion bar conductor  1000  wherein the tip section  1001  is a moment arm that protrudes farther out from the channel  1007  in the connector body  1002  of an electrical interconnection device than tip section  1003  of torsion bar conductor  1004 . If conductive element  1005 ,  1006  are on the same surface of an electrical component such as a printed circuit board, then torsion bar conductor  1000  will contact conductive element  1005  before torsion bar conductor  1004  will contact conductive  1006 . In this embodiment, one electrical signal makes electrical contact first before other signals, which may be useful, among other things, by allowing a ground to be established prior to other connections in order to protecting sensitive devices within the electrical component being interconnected. 
         [0090]    The connector body  1002  may be molded or otherwise formed from an integral material, or may include one or more assembled components. Also, the channel  1007  may be a through-hole in the connector body  1002  or may be a cavity (i.e., extending only part way through the connector body  1002 ) and, in either case, may include one or more turns or angles, for example, to form a right-angle or other-angled connector. The channel  1007  may have an annular interior surface to form a cylindrical pathway or may have a polygonal interior surface (i.e., having a cross section that has three or more sides). 
         [0091]    The connector body  1002  may be formed from a conductive material (e.g., made of conductive material or having a conductive coating) or from an insulating material (i.e., coated with or made of a material having a desired dielectric constant). Also, in the event that the connector body  1002  has a conductive surface, the conductive element  1004  may be insulated from the connector body by an insulating sheath, tube or other structure disposed within the channel  1007 . 
         [0092]      FIG. 11  illustrates an isometric view of an embodiment, a torsion bar conductor  1100  in which the axis of the torsion section  1101  of the torsion bar conductor  1100  and the axis of the inclined tip sections  1102 ,  1103  are all in the same plane. The torsion section  1101  could is contained in a closely confining channel in a structure (not shown) that allows the torsion section  1101  to twist when moments are applied to the tip sections  1102 ,  1103 . The moment direction  1104  is the opposite of moment direction  1105 . Alternatively, a fixed section could be included at the center of the torsion section  1101 , holding a portion of the torsion conductor in a fixed position to prevent rotation at that point, allowing the moments applied to the tip sections to be in the same direction, yet the torsion sections would still twist to create a spring effect. 
         [0093]      FIG. 12  further illustrates the shape of the torsion bar conductor  1100  in top, front and right views. The top view shows the tip sections included at a 45 degree angle to the torsion section. The right view shows the axes of tip section  1102 ,  1103  inclined at a 180 degree angle  1200  to each other. 
         [0094]      FIG. 13  illustrates the torsion bar conductors  1100  shown in  FIG. 11  fitted into closely conforming channels in a connector body  1301 . Another dielectric layer, not shown here, that clamps over the torsion bar conductors  1100  shown in  FIG. 13 , has the same closely conforming channels. These two insulating layers fully enclose the conductors to form a cylindrical cavity for the conductors to rotate within. The close-up illustrates the tip section  1102  inclined at an angle to the torsion section of the conductor and the cavity  1302  through which the tip section  1102  rotates. Because the two end sections  1102 ,  1103  are bent at opposing angles at the ends of any torsion bar conductors  1100 , the central portions  1303  of the torsion bar conductors  1100  do not necessarily have to be fixed with respect to the channel because the moments generated oppose each other, causing the torsion section  1303  to twist and creating the spring effect at the end sections  1102 ,  1103 . However, the connector&#39;s other torsion bar conductors are longer or shorter in nearby layers. To maintain the same moment value in torsion bar conductors throughout the connector, the fixed length of the torsion section  1303  of any torsion bar conductor can be adjusted so that the moment values are always the same. To prevent the torsion bar conductors  1100  from rotating in the fixed length of the torsion section  1303 , the torsion bar conductor&#39;s cross section may be made square, rectangular or some other shape that would not rotate if the enclosing channel closely conformed to that shape. The bar&#39;s fixed length of the torsion section  1303  could also be adhered to the channel using adhesives, solder or weld attachments or other mechanical restraints. The torsion bar conductors may be etched, stamped, or laser-cut from a sheet of conductive material or may be fabricated by some other method, dropped into the electrical interconnection device assembly, and then connecting bars between the conductors removed. 
         [0095]      FIG. 14  illustrates a torsion bar conductor ground plane  1400  wherein torsion bar conductors  1401  may be etched, stamped, or laser-cut from a sheet of conductive material or may be fabricated by some other method. The moment arms  1402 ,  1403  can be arranged at different angles with respect to each other as previously described in this document. The rectangular portion  1404  in the middle of the ground plane can be made larger or smaller so that the lengths of the torsion bar conductors  1401  are all of the same length if so desired. This insures that the moments of all conductors in the connector can have the same value if desired or have each conductor assigned a specific value. 
         [0096]      FIG. 15  illustrates the torsion bar conductor ground plane  1400  in  FIG. 14  when it is seated in a cavity within a layer  1501 . The layer&#39;s material can be either conductive or insulative or the layer  1501  may be conductively coated on the surface and in the cavity under the ground plane. The layer  1501  has closely conforming channels for the torsion bar conductors  1401  to rotate within. Another layer, not shown here, clamps over the torsion bar conductors and has the same closely conforming channels thus fully enclosing all of the straight torsion sections  1502  of torsion bar conductors  1401  and permitting the conductors to rotate. 
         [0097]      FIG. 16A  is a view of the torsion bar conductor  1401  perpendicular to the central axis of the torsion section  1502  of the torsion bar conductor  1401 .  FIG. 16B  is a view of the torsion bar conductor  1401  looking down the axis of the torsion section  1502  of the torsion bar conductor  1401 .  FIGS. 16A and 16B  illustrate the point  1601  at which electrical contact is created between the torsion bar conductor  1401  and a conductive channel  1603 . The point  1602  is the electrical contact point between the torsion bar conductor  1401  and the electrical contact pad, not shown, of the printed circuit board. The arrows in each view point to the electrical contact points.  FIGS. 16A and 16B  illustrate the short current path between point  1601  and  1602 . 
         [0098]      FIG. 17  illustrates a layer  1501  in which half of the channel  1603  and the planar surface  1701  identified by the shading in the figure, are conductively coated and are a continuous entity. When combined with the torsion bar conductor ground plane  1400 , the combination acts as ground plane for a transmission line structures. The current path could flow directly through point  1601 , in  FIG. 16 , into the ground plane thereby decreasing inductive signal discontinuities and helping to maintain the uniformity of the transmission line&#39;s electromagnetic field. 
         [0099]      FIG. 18  illustrates a side view of the electrical connector  1800  wherein dielectric layer  1501  with a conductive coating on the upper surface and a similar dielectric layer  1801  with a conductive coating on the lower surface enclose torsion bar conductor ground plane  1400 . Torsion bar conductor ground plane  1803  is enclosed in a similar manner by dielectric layers  1802  and  1804 . Torsion bar conductors  1100  are enclosed by dielectric layers  1501  and  1804 , whose lower and upper surfaces are not conductively coated. 
         [0100]      FIG. 19  illustrates a cross section through the electric connector  1800  in  FIG. 18 . The close-up at the top of the figure shows the printed circuit board&#39;s electrical contact pads  1901  beginning to touch the torsion bar conductors&#39; electrical contacts  1902 . The close-up on the right illustrates the printed circuit board&#39;s electrical contact pads  1903  when they are fully mated with the torsion bar conductors&#39; electrical contacts  1904 . The torsion bar conductor  1100  is a signal path with torsion bar conductor ground planes  1400 ,  1803  above and below it respectively. The figure illustrates the small feature sizes of the moment arms  1402 ,  1403  and corresponding small cavities  1908  through which the moment arms  1402 ,  1403  rotate. These moment arms and cavities can be made very small and as they become smaller, they disturb the impedances of the connector&#39;s transmission line geometries at higher and higher frequencies in comparison to the prior art. 
         [0101]      FIG. 20  illustrates an embodiment, the electrical connector in  FIG. 19  wherein the printed circuit boards can be disposed at 180 degrees or some other angle to each other and at any distance from each other. The distance between the electrical connector&#39;s torsion bar conductors  2001  are maintained so that the signal integrity and impedance of the transmission line is uniform throughout the connector if desired. The printed circuit board  2002  at the lower left has all the electrical contact pads  2004  at the top surface. The printed circuit board  2003  on the lower right has a stair step configuration in which the rows of electrical contact pads  2005  are on different surfaces of the stair step.  FIG. 20  also illustrates how signal integrity discontinuities are kept to a minimum by keeping the moment arms and surrounding cavities small relative to other prior art electrical connectors. 
         [0102]      FIG. 21  illustrates how the electrical connector&#39;s electrical contact rows shown in  FIG. 18  may be adapted into a stair step configuration  2101  so they may interface with rows of electrical contact pads on stair step printed circuit boards. Although  FIG. 21  implies that the printed circuit boards are at 90 degrees to each other, they may be at other angles. 
         [0103]      FIG. 22  further clarifies  FIG. 21  by showing the electrical connector&#39;s moment arms  1102 ,  1402  in an isometric view  2200  in which the close-up at top right shows moment arm  1402  protruding through cavity  1908  and the close-up at bottom right shows moment arm  1102  protruding through cavity  1302 . 
         [0104]      FIG. 23A  illustrates the moment arm  1102  protruding through cavity  1302 . The arrow  2301  shows the direction through which the moment arm  1102  rotates as the printed circuit board&#39;s electrical contact pad (not shown) mates with the electrical connector  1800 .  FIG. 23B  shows the moment arm&#39;s final position as it withdraws into the cavity  1302  and the electrical connector  1800  has fully mated with the printed circuit board. 
         [0105]      FIG. 24  illustrates that either end of the torsion bar conductor  2401  can be inclined at different angles .alpha. or .beta. with respect to the printed circuit boards  2402 ,  2403  by bending the torsion bar conductor  2401  within its torsion section. The angles .alpha. or .beta. can include an orientation of the torsion bar conductor  2401  wherein its torsion section is closer to or farther away from the viewer than its moment arms  2404 ,  2405 . Thus the torsion bar conductor  2401  does not have to be straight in order to operate. Any of the angles .alpha. or .beta. in  FIG. 24  may be changed to obtain different property values including contact forces, direction of contact wipe, contact location or connector size and shape. 
         [0106]      FIGS. 25 and 26  illustrate another torsion bar conductor configuration useful for incorporation into an embodiment, a flat or stair step connector as shown in  FIGS. 27 through 30 .  FIG. 25  illustrates a torsion bar conductor  2500  similar to the torsion bar conductor  1100  in  FIG. 11  except that the moment arms  2502 ,  2503  are bent downward with respect to the axis of the torsion bar conductor&#39;s torsion section  2501 . The moment arms  2502 ,  2503  rotate in the same directions  2504 ,  2505  as the moment arms in  FIG. 11 . 
         [0107]      FIG. 26  further clarifies the shape of the torsion bar conductor  2500  in top, front and right views. In the right view, the axes of the moment arms  2502 ,  2503  are generally at but not limited to a 90 degree angle  2600  to each other. The arrows indicate their direction of twisting action  2504 ,  2505  when the torsion bar conductor  2500  is pressed down upon electrical contact pads whose surfaces are generally in the same plane. 
         [0108]      FIGS. 27 through 29  illustrate an embodiment, an electrical connector  2700  with a stair step configuration  2701  whose rows of electrical contacts  2702  can interface with corresponding rows of electrical contact pads on electrical components such as stair step printed circuit boards (not shown). The electrical connector  2700  uses the torsion bar conductors  2500 . The center portion of the torsion bar conductors may be replaced by and be conductively attached to conductive entities such as etched signal traces of a flexible circuit, wires in a cable or coaxial structures in a coaxial cable. These conductive entities may have various lengths and curvatures allowing the electrical interconnection of distantly placed electrical components. 
         [0109]      FIG. 28  further clarifies the electrical connector  2700  in  FIG. 27  by showing front, bottom and right views. The right view shows the stair step configuration  2800  of the rows of electrical contacts  2702 . 
         [0110]    In  FIG. 29 , the top dielectric layer  2901  of electrical connector  2700  is partially sectioned to show the torsion bar conductors  2800 . The torsion bar conductors  2500  captured by closely conforming channels in the bottom surface of top layer  2901  and closely conforming channels in the top surface of the second dielectric layer  2902 . 
         [0111]      FIG. 30  illustrates how cavities  3001  are placed within the second dielectric layer  3002  or any dielectric layer and underneath the torsion bar conductors  2500  to reduce the relative dielectric constant and increase the signal&#39;s propagation velocity. The cavities  3001  may be filled with air, dielectric foam or a dielectric with a relative dielectric constant whose value is lower than that of the material surrounding the cavities. 
         [0112]      FIG. 31  illustrates the torsion bar conductor  2500  supported by insulated channel spacers  3102  in cavities  3101 . The cavities  3101  may be filled with air, dielectric foam or a dielectric with a relative dielectric constant whose value is lower than that of the material surrounding the cavities. The walls of the cavities  3101  can be conductively coated, as illustrated by shading, to create a ground return path. The ground return path and the torsion bar conductor  2500  create a waveguide such as a coaxial transmission line. The cavities  3101  lower the effective dielectric constant and increase the signal&#39;s propagation velocity. 
         [0113]      FIG. 32  is another embodiment, an electrical connector  3200  similar to the electrical connector  2700  in  FIG. 27  except that the moment arms  3202 ,  3203  of the torsion bar conductors  3201  protrude through the bottom and top surfaces of the connector body  3204 . The rows of electrical contacts formed by the moment arms  3202 ,  3203  are in a stair step configuration to match the electrical contact pads on the stair step printed circuit boards  3205 ,  3206  whose electrical contact pads are opposite each other. 
         [0114]      FIG. 33  is an embodiment, an electrical connector  3300  wherein the torsion bar conductors  3301  are attached to, or are an extension of conductive entities  3303  such as etched signal traces of a flexible circuit, wires in a cable or coaxial structures in a coaxial cable. The rows of electrical contacts at the ends of the moment arms  3302  protrude downward through the bottom surface of the connector body  3304  in a stair step configuration  3305 . The electrical connector  3300  mates with the electrical contact pads on the stair step printed circuit board  3306 . 
         [0115]      FIG. 34  is an embodiment shown in  FIG. 27 .  FIG. 34  illustrates how the normally straight sections of torsion bar conductors  3401  can be bent at various angles. This allows the moment arms  3402  to rotate in a plane coincident with the axes of aligned electrical contact pads  3404  of printed circuit boards. Thus the contact wipe created by this action is in the same direction as the axes  3404  of the electrical contact pads on the printed circuit board. In previously shown embodiments of the invention, the electrical contact pads had to be widened to accommodate the torsion bar conductors&#39; contact wipe that was perpendicular to the torsion section of the torsion bar conductor and the axes of the signal traces. An electrical contact pad whose perimeter is at abrupt right angles to the signal trace decreases signal integrity. In addition,  FIG. 34  shows how the torsion bar&#39;s length  3403  is kept equal in each torsion bar conductor and shorter than the overall length of the torsion bar conductor. The latter is done to insure that the contact force or moment value is kept the same from conductor to conductor and at either end of any torsion bar conductor. 
         [0116]      FIG. 35  illustrates another embodiment wherein the torsion bar conductors  3501  are curved rather than straight. The torsion bar conductors  3501  are inside closely conforming channels that confine the curved portion of the torsion bar conductors  3501  but allow them to rotate. The contact wipe is in the direction of the axes of signal traces  3502  on the printed circuit boards  3503  and provides the same improved signal integrity as in  FIG. 34 . This configuration allows increase electrical contact density. 
         [0117]      FIG. 36  illustrates an embodiment, electrical interconnection device in which the torsion bar conductors  3601  are embedded inside the layers of a printed circuit board  3602 .  FIG. 36  shows the printed circuit board&#39;s top layer sectioned to show the torsion bar conductors  3601  underneath. The central portion of torsion bar conductors  3601  may be replaced by flexible conductive wires, center conductors inside coaxial cable or the like or a combination of them. Any of the latter structures or the central portion of torsion bar conductors  3601  may be routed in varying directions and with different bends on one layer, and if needed, may be dropped down to another layer. Etched copper traces may also take the place of the previously mentioned conductive wires. In such a manner, signals may be routed from one layer of the printed circuit board to another. 
         [0118]      FIG. 37  is a cross section  3700  of  FIG. 36  showing the tip sections  3603  in their cavities. 
         [0119]      FIG. 38  illustrates another embodiment, a torsion bar conductor  3800  with multiple electrical contacts  3801  at the ends of projections  3802  and at tip sections  3804 . As shown, the projections  3802  may be formed by bends (three bends are shown in  FIG. 38 ) in the torsion bar conductor  3800 , though other structures may be used to form the projections in alternative embodiments. 
         [0120]    In  FIG. 39 , the torsion bar conductors  3800  are embedded inside the layers of a printed circuit board  3900  for use as a signal or power bus connector. The multiple electrical contact points  3801  allow the same signal to be accessible at several places on the printed circuit board  3900 . 
         [0121]      FIG. 40  illustrates the bus connector with the top layer of the printed circuit board  3900  removed to show the location and orientation of the torsion bar conductors  3800 , which are confined by channels in the bottom layer  4001  of the printed circuit board. One torsion bar conductor  3800  has multiple electrical contacts  3801  and the torsion bar conductors&#39; geometry creates contact force for each electrical contact. 
         [0122]      FIG. 41  illustrates another embodiment, an electrical connector  4100  wherein push pins  4102 ,  4107  are combined with the torsion bar conductor  4101 . When the electrical connector is unmated, the electrical contact pad  4105  on printed circuit board  4106  is shown just as it touches push pin  4102 . In this condition, the tip section  4104  has driven the push pin  4102  downward so that it fully protrudes through a hole in the locating plate  4103 . When the electrical connector  4100  is mated, the electrical contact pad  4110  of the printed circuit board  4108  urges the push pin  4107  farther into the hole of the locating plate  4111  and places force on tip section  4109 . When tip section  4109  is fully actuated, it creates an electrical connection between the contact pad  4110  and push pin  4107  and between push pin  4107  and torsion bar conductor  4101 . 
         [0123]      FIG. 42  is a close-up view of the push pins  4102  in  FIG. 41 . As contact pitches grow smaller, it becomes harder to align the connector&#39;s electrical contacts  4202  on torsion bar conductors  4101  to the electrical contact pads  4105  on the printed circuit boards. Push pins  4102  provide an additional opportunity for alignment. If the diameters of the push pins  4102  and their enclosing holes are fabricated with small tolerances, movement of the push pins&#39; axes will be limited. To provide contact wipe between the push pins  4102  and electrical contact pads  4105 , the pin can be made to twist about its central axis. A broach with a twist in it can be used to fabricate the holes in the locating plates  4103 . Or the twist may be molded into the locating plate&#39;s holes or may be fabricated by some other method. The push pin could have one or more protrusions or bumps on its outer surface that follows the resulting twist feature on the hole&#39;s cylindrical surface. The protrusions or bumps may be fabricated of an insulating material to provide better signal integrity. An alternative embodiment is to reverse the features and place the twist feature on the pin or the pin&#39;s insulating collar and the bump or bumps on the hole&#39;s cylindrical surface. The twist feature may also be manipulated by changing the thread pitch. Another alternative embodiment places external threads on the push pin and internal threads on the diameter of the holes in the locating plate. 
         [0124]      FIG. 43  illustrates an embodiment of an electrical connector  4300  in which the torsion bar conductors  4301  are the center conductors in coaxial transmission lines. The torsion bar conductors  4301  are encased in dielectric tubes  4302 , which are in turn encased in closely conforming channels  4303  in the top housing  4308  and the bottom housing  4309 . The housings can be coated with a conductive film as indicated by the shaded area  4304 . The torsion bar ground conductors  4305  are placed next to each coaxial transmission line. The torsion bar ground conductors  4305  route the ground signals from one end of the electrical connector  4300  to the other. When the electrical connector is forced down upon the electrical contact pads of one or more printed circuit boards, the tip sections  4306 ,  4307  rotate upward creating contact force. 
         [0125]      FIG. 44  illustrates a bottom view of the electrical connector  4300  in  FIG. 43 . The visible portion of a tip section  4306  of a torsion bar conductor  4301  can be spaced an appropriate distance  4400  away from the tip section  4307  of the torsion bar ground conductor  4305  to match the characteristic impedance of the coaxial structure. The distance  4400  can be adjusted by extending cavity  4401  deeper into the bottom housing  4309  than cavity  4402 . 
         [0126]      FIG. 45  illustrates an embodiment, an electrical connector  4500  wherein torsion bar conductors  4504  in coaxial transmission lines are seated in the bottom housing  4501  comprised of a center portion (shown as the shaded area), whose material is conductive, and the two insulating strips  4502  residing on either side of the center portion and next to the tip sections  4306 . The outer diameter of the round coaxial tubing  4503  is shown conductively coated, but does not necessarily have to be conductively coated. The last round coaxial tubing  4503  to the right is sectioned (shown by cross-hatching) to show the torsion bar conductor  4504  within. 
         [0127]      FIG. 46  illustrates a bottom view of the electrical connector  4500  in  FIG. 45  that shows the conductive bottom surface  4600  of the bottom housing  4501  indicated by the shaded area. When the electrical connector  4500  is mated to a printed circuit board, the conductive bottom surface  4600  can make electrical contact to grounded areas of the printed circuit board by using compression contacts, conductive bumps, soldering, welding, conductive elastomeric films or other means. In  FIGS. 43 through 46 , the figures imply that the coaxial structure is cylindrical. However, the cross section profile of the coaxial transmission lines may be square, rectangular or some other shape. 
         [0128]      FIG. 47  illustrates a vertical interposer conductor  4701  that can be used in an electrical interposer connector. The vertical interposer conductor  4701  is shaped so that the tip sections  4702  and the electrical contact points  4703  at the ends of the tip sections rotate in the same plane. The axes of rotation of the tip sections  4702  are the axes of the torsion bars  4704 . The torsion bars  4704  can be enclosed within closely fitting cavities that confine the torsion bars  4704 , but allow the torsion bars to twist due to the tip sections being rotated about the axes of the torsion bars. Because the axes of the torsion bars  4704  are parallel and connected at one end, the electrical contact points  4703  can be closer together vertically thus making the electrical interposer thinner than other interposer interconnection devices. The torsion bars  4704  can be made longer or shorter in the axial direction to adjust the value of the moment and thus the contact force at the electrical contact points  4703 . 
         [0129]      FIG. 48  illustrates an embodiment, an electrical interposer  4801  that has a plurality of torsion bar conductors  4701  embedded in closely conforming channels inside a top insulative layer  4802  and a bottom insulative layer  4803 . The electrical contact points  4703  protrude through the top insulative layer  4802  and bottom insulative layer  4803 . Because the electrical contact points  4703  below the electrical interposer  4801  are vertically aligned over the electrical contact points  4703  above the electrical interposer  4801 , the electrical contact pads on the first printed circuit board can be vertically in line with the electrical contact pads on the second printed circuit board. 
         [0130]      FIG. 49  illustrates the electrical interposer  4801  with top insulative layer  4802  removed. The enlarged view on the top right shows the torsion bar conductors  4701  residing in cavities in the bottom insulative layer  4803 . The enlarged view on the lower right illustrates the torsion bar conductors  4701  without the bottom insulative layer  4803  to show the torsion bar conductors&#39; relationship and orientation to the insulative layers  4802 ,  4803  and to each other. The walls of the cavities within which the torsion bar conductors  4701  reside could have the shape of two closely conforming cylinders. If the cylindrical cavities are conductively coated, the signal&#39;s current (I)  4901  can travel as directly as possible from one electrical contact point  4703  on the torsion bar conductor  4701  to its other electrical contact point  4703  through the conductive coating thus making the torsion bar conductors  4701  less inductive. 
         [0131]      FIG. 50  illustrates an embodiment, a stair step electrical interposer  5000  with rows of torsion bar conductors  4701  captured between an upper insulative layer  5001  and a lower insulative layer  5002 . The enlarged view to the right shows the upper insulative layer  5001  with a section removed that exposes the upper half of the torsion bar conductors  4701 . The stair step configurations  5003 ,  5004  are shown in the stair step electrical interposer  5000  and in the well in the stair step printed circuit board  5005  respectively. A stair step electrical interposer may have rows of electrical contacts that may be at various angles or orientations to each other. 
         [0132]    In  FIGS. 48 and 50 , portions of the insulative layers may be conductively coated or made conductive by other means to provide a ground return path for high frequency signals traveling through the electrical interposer  4801  or stair step electrical interposer  5000 . When the geometry, dimensions and properties of the signal transmission line comprising the ground return path, dielectric material, and torsion bar conductors are tuned correctly, they create a high-speed, high-density transmission line with improved signal integrity. 
         [0133]      FIG. 51  illustrates an offset interposer conductor  5100  for use in electrical interposers. When actuated, tip section  5101  rotates in a counterclockwise direction  5102  and tip section  5103  rotates in a clockwise direction  5104 . Channels in the insulative layers (not shown) in the electrical interposer capture the torsion bar  5105 . The offset interposer conductor  5100  is smaller, simpler in design and easier to fabricate than torsion bar conductor  4701 . 
         [0134]      FIGS. 52A and 52B  illustrate another embodiment, an electrical circular connector system  5200  comprised of a plug electrical connector and a receptacle electrical connector, wherein a plug housing  5203  holds the torsion bar conductors  5204  in a circular arrangement. The mating receptacle conductors  5202  are arrayed inside a receptacle housing  5201  in a circular pattern. A surface on the end of the receptacle conductor  5202  is inclined at an angle so that it acts as a ramp  5205  for the torsion bar conductor&#39;s electrical contact  5206  as the two conductors are mated together. As the torsion bar conductor&#39;s electrical contact  5206  moves up the ramp  5205 , the tip section twists and creates a moment in the torsion bar conductor. Torsion bar conductors in circular arrangements with larger or smaller diameters that are concentric with the aforementioned torsion bar conductors  5202 ,  5204  may be added to the electrical circular connector system  5200 . 
         [0135]    The end of a signal trace on a flexible circuit may be formed into an electrical contact pad that mates with the electrical contact  5206  on the end of the torsion bar conductor  5204 . Thus a separate receptacle conductor  5202  would be not required. Either conductor  5202  or  5204  may be attached to conductive entities such as flexible circuit traces, wires in a cable, conductors in coaxial transmission lines or the like. The back end of each connector may be conductively attached to other electronic components such as printed circuit boards or IC packages by soldering, welding, compression contacts, conductive films or other means. 
         [0136]      FIG. 53A  shows another embodiment, an electrical circular connector system  5300  in which the torsion bar conductors  5301  are in a circular array residing inside a circular plug housing (not shown) and the receptacle conductors  5302  are in a circular array residing inside a circular receptacle housing (not shown). In  FIGS. 53A and 53B , the housings have been drawn together in the housings&#39; axial direction, but not rotated with respect to each other so that the electrical contacts  5303  on the torsion bar conductors  5301  are at the bottom of the receptacle conductors&#39; ramps  5304 . The next step in mating the connector in  FIGS. 53A ,  53 B is illustrated in  FIGS. 54A ,  54 B wherein rotation of the housings with respect to each other causes the electrical contacts  5303  on the torsion bar conductors  5301  to travel up the ramps  5304  on the receptacle conductors  5302 . This action twists the torsion bar conductors  5301  creating contact force F.sub.c. As the electrical contacts  5303  travels beyond the ramps  5304  onto the curved surfaces  5400 , the torsion bar conductors  5301  stop twisting further. The latter occurs because the radius of curvature on all curved surfaces  5400  of each receptacle conductor  5302  is equal to one half the diameter shown and all the curved surfaces  5400  are coincident with a cylinder defined by the diameter shown. Thus if the housings do not rotate to an exact predefined angular position, then the value of the contact force does not vary as in a receptacle conductor wherein curved surfaces  5400  were instead flat surfaces. If the housings rotate to mate the conductors, the rotation action can lock the connector halves together. In addition, torsion bar conductors in circular arrangements with larger or smaller diameters that are concentric with the aforementioned torsion bar conductors  5301 ,  5302  may be added to the electrical circular connector system  5300 . 
         [0137]    The torsion bar conductors in  FIGS. 52A through 54B  are arrayed in circular configurations. However, they may also be arrayed in rows and columns in rectangular, square or other geometric arrangements. When the conductors are in these other configurations, the connectors may be mated by either drawing the connector housings together in an axial direction or sliding the conductors&#39; electrical contact surfaces over each other from a number of directions. 
         [0138]      FIGS. 55A through 58  illustrate another embodiment, an arrayed conductor electrical connector system in which the tip sections on torsion bar conductors make electrical contact with the torsion bars on the mating torsion bar conductors. In  FIGS. 55A ,  55 B, torsion bar conductors  5502 ,  5503  are enclosed in connector bodies  5501 ,  5504  respectively.  FIG. 55B  illustrates the assembly in  FIG. 55A  without connector body  5504  in which connector body  5504  is a mirror image of connector body  5501 . The tip section  5506  on torsion bar conductor  5503  is beginning to slide to the left on ramp  5505  on connector body  5501 . In the same manner, the end of the tip section  5507  on torsion bar conductor  5502  is simultaneously sliding to the right on ramp  5508  on connector body  5504 . The axis of the moment arm and the axis of the torsion bar in torsion bar conductor  5503  define the plane  5509 . Torsion bar conductor  5502  also has a plane (not shown), defined in the same manner, which is parallel to plane  5509 . In  FIGS. 56A ,  56 B, the torsion bar conductors  5502 ,  5503  are brought closer together causing ends of the tip sections  5506 ,  5508  to travel farther along the ramps  5505 ,  5508 . This causes the tip sections  5506 ,  5508  of torsion bar conductors  5502 ,  5503  to rotate through intermediate angle  5600  defined by planes  5509  and  5601 . In  FIGS. 57A ,  57 B, the tip sections  5506 ,  5508  of torsion bar conductors  5502 ,  5503  have moved past the guiding ramps  5505 ,  5508  and the electrical connector system  5500  has fully mated. The torsion sections of torsion bar conductors  5502 ,  5503  are fully twisted which provides contact force at electrical contact points  5700 ,  5701 . Thus the tip sections of torsion bar conductors  5502 ,  5503  have rotated through final angle  5703  defined by planes  5509  and  5702 . The cylindrical surface of each tip section contacts the cylindrical surface of the torsion bar on the mating torsion bar conductor. The axes of these cylindrical surfaces cross each other, which provides a reliable electrical contact geometry. The torsion bar conductors illustrated in  FIGS. 55A through 57B  can arrayed in circular configurations or in rows and columns in rectangular, square or other geometric arrangements inside two-part electrical connector systems. 
         [0139]      FIG. 58  illustrates an electrical connector assembly  5800 , which is one half of a two-part, rectangular, electrical connector system. The electrical connector assembly  5800  is composed of an array of connector bodies  5501  and torsion bar conductors  5502 . An electrical connector assembly (not shown) composed of an array of connector bodies  5503  and torsion bar conductors  5504  mates with electrical connector assembly  5800  and comprises the two-part, rectangular, electrical connector system. The electrical connector assemblies may also be arrayed in circular configurations or other geometric arrangements. 
         [0140]    In  FIGS. 52A through 58 , torsion bar conductors mate with other torsion bar conductors, as illustrated by  FIGS. 55A through 57B  in two-part, electrical connector systems. These embodiments improve signal maintenance during shock and vibration, establish electrical connections with redundant electrical contact points, and reduce or eliminate capacitive stubs. 
         [0141]    Although the invention has been described with reference to specific exemplary embodiments thereof, it will be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.