A cable assembly includes a contact ribbon made of a single stamping and including pairs of first and second signal contacts and includes a cable including pairs of first and second center conductors connected to corresponding pairs of first and second signal contacts. The contact ribbon includes a ground plane, a first row of ground contacts extending from the ground plane in a row along a first side of the ground plane such that a first line extending through the first row of ground contacts does not intersect with any signal contacts, and a second row of ground contacts extending from the ground plane in a row along a second side of the ground plane such that a second line extending through the second row of ground contacts does not intersect with any signal contacts.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to connectors for high-speed signal transmission. More specifically, the present invention relates to connectors in which wires are directly connected to contacts of the connectors.

2. Description of the Related Art

High-speed cable routing has been used to transmit signals between substrates, such as printed circuit boards (PCBs), of electronic devices. Conventional high-speed cable routing often requires routing in very tight and/or low-profile spaces. However, as data rates increase (i.e., as the frequency of the high-speed signal increases), the cost of high-performance high-speed transmission systems increases as well. High-speed signals transmitted between substrates generally follow a path of:1) a trace on a transmitting substrate;2) a first connector mounted to the transmitting substrate;3) a substrate of a second connector that is inserted into the first connector;4) a high-speed cable connected to the second connector substrate at a transmitting end of the high-speed cable;5) a substrate of a third connector connected to the high-speed cable at a receiving end of the high-speed cable;6) a fourth connector, mounted to a receiving substrate, that receives the third connector substrate; and7) a trace on the receiving substrate.

Conventional high-speed cable assemblies typically include two connectors (i.e., the second and third connectors listed above) that are connected by high-speed cables. Accordingly, conventional high-speed cable routing also requires two additional connectors (i.e., the first and fourth connectors listed above) to connect the high-speed cables to transmitting and receiving substrates.

The signal quality is affected every time the transmitted signal transfers from each of the listed items above. That is, the signal quality is degraded when the signal is transmitted between 1) the trace on the transmitting substrate and 2) the first connector mounted to the transmitting substrate, between 2) the first connector mounted to the transmitting substrate and 3) the second connector substrate that is inserted into the first connector, etc. The signal quality can even be affected within each of the items above. For example, a signal transmitted through the trace on the transmitting or receiving substrate can suffer significant insertion loss.

High-speed cable assemblies are relatively expensive, due in part to the cost high-speed cable and the two connectors that include substrates (i.e., the second and third connectors listed above). Each connector of the high-speed cable assembly also requires processing time. Thus, the full cost of a high-speed cable assembly cable includes the cable, the high-speed-cable-assembly connectors on each end of the cable, the processing time required for each of these connectors, and the area required on a substrate for each connector.

To reduce the overall size of the high-speed cable assembly, smaller connectors and cables have been attempted. However, using smaller connectors and cables can both increase the cost and reduce the performance of high-speed cable assemblies. Eliminating the high-speed cable assembly has been attempted by transmitting the signal only on substrates. However, signals transmitted on a substrate generally have higher insertion losses compared to many cables, including, for example, micro coaxial (coax) and twinaxial (twinax) cables. Thus, eliminating the high-speed cable assembly can result in reduced signal integrity and degraded performance.

Exotic materials and RF/Microwave connectors have been used to improve the performance of high-speed cable assemblies. However, such materials and connectors increase both the cost and the size of a high-speed cable assembly. Low-cost conductors, dielectrics, and connectors have been used to reduce the overall cost of systems that rely on high-speed cable routing. However, low-cost conductors, dielectrics, and connectors decrease the performance of high-speed cable assemblies and can also increase their size.

SUMMARY OF THE INVENTION

To overcome the problems described above, preferred embodiments of the present invention provide a high-speed cable assembly that is relatively small in size, cheap, and has high performance.

Preferred embodiments of the present invention provide a high-speed cable assembly with a low-profile connection to a substrate. Because the high-speed cable assembly connects perpendicularly or substantially perpendicularly to the substrate, zero keep-out space on the substrate is needed for slide insertion. Because there is no mating connector required on the substrate, the total amount of required system space, including on the substrate, is significantly reduced. The high-speed cable assembly also uses fewer connectors, resulting in fewer transitions in the signal transmission path. Fewer transitions simplifies the signal transmission path, improves system performance, and reduces costs.

According to a preferred embodiment of the present invention, a cable assembly includes a contact ribbon made of a single stamping including a plurality of pairs of first and second signal contacts; a ground plane; a first row of ground contacts extending from the ground plane in a row along a first side of the ground plane such that a first line extending through the first row of ground contacts does not intersect with any signal contacts of the plurality of pairs of first and second signal contacts; and a second row of ground contacts extending from the ground plane in a row along a second side of the ground plane such that a second line extending through the first row of ground contacts does not intersect with any signal contacts of the plurality of pairs of first and second signal contacts; and includes a cable including a plurality of pairs of first and second center conductors, each pair of the plurality of pairs of first and second center conductors is connected to a corresponding pair of the plurality of pairs of first and second signal contacts; a plurality of insulators each surrounding a corresponding pair of the plurality of pairs of first and second center conductors; and a shield that surrounds the plurality of insulators and that is connected to the ground plane.

The plurality of pairs of first and second signal contacts are preferably arranged in a single row. A first distance between the first row of ground contacts and the second row of ground contacts is preferably greater than a second distance between the single row of the plurality of pairs of first and second signal contacts and either of the first row of ground contacts or the second row of ground contacts. The first row of ground contacts and the second row of ground contacts are preferably located on the same side of the plurality of pairs of first and second signal contacts. Preferably, the contact ribbon is included in a housing, and a support member connecting the plurality of pairs of first and second signal contacts is removed from the contact ribbon after the contact ribbon is included in the housing.

The cable is preferably a twinaxial cable. The plurality of pairs of first and second signal contacts are preferably press-fit contacts or solderable contacts.

According to a preferred embodiment of the present invention, a method of manufacturing a cable assembly includes providing a contact ribbon including a plurality of pairs of first and second signal contacts; a ground plane; a first row of ground contacts extending from the ground plane in a row along a first side of the ground plane such that a first line extending through the first row of ground contacts does not intersect with any signal contacts of the plurality of pairs of first and second signal contacts; and a second row of ground contacts extending from the ground plane in a row along a second side of the ground plane such that a second line extending through the first row of ground contacts does not intersect with any signal contacts of the plurality of pairs of first and second signal contacts, providing a cable with a plurality of pairs of first and second center conductors, a plurality of insulators each surrounding a corresponding pair of the plurality of pairs of first and second center conductors, and a shield that surrounds the plurality of insulators, connecting each pair of the plurality of pairs of first and second signal contacts to a corresponding pair of the plurality of pairs of first and second center conductors at a first end of the cable, and connecting the shield to the ground plane at the first end of the cable.

Each pair of the plurality of pairs of first and second signal contacts is preferably connected to the corresponding pair of the plurality of pairs of first and second center conductors by crimping or soldering. The shield is preferably connected to the ground plane by soldering.

The method of manufacturing a cable assembly further preferably includes forming a housing for the contact ribbon before a support member connecting the plurality of pairs of first and second signal contacts is removed. Preferably, the housing includes at least one hole, and the support member is removed by punching or cutting the support member through the at least one hole of the housing.

The method of manufacturing a cable assembly further preferably includes attaching the cable assembly to a substrate before a support member connecting the plurality of pairs of first and second signal contacts is removed. Each signal contact of the plurality of pairs of first and second signal contacts is preferably connected to a corresponding hole in the substrate by soldering.

The plurality of pairs of first and second signal contacts are preferably press-fit contacts or solderable contacts. The plurality of pairs of first and second signal contacts are preferably arranged in a single row. A first distance between the first row of ground contacts and the second row of ground contacts is preferably greater than a second distance between the single row of the plurality of pairs of first and second signal contacts and either of the first row of ground contacts or the second row of ground contacts.

The first row of ground contacts and the second row of ground contacts are preferably located on a same side of the plurality of pairs of first and second signal contacts.

The above and other features, elements, steps, configurations, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described in detail with reference toFIGS. 1 to 19. Note that the following description is in all aspects illustrative and not restrictive and should not be construed to restrict the applications or uses of the present invention in any manner.

FIGS. 1 and 2show a contact ribbon10according to a preferred embodiment of the present invention. The contact ribbon10includes one or more ground contacts11, one or more first contacts12, and one or more second contacts13to provide physical and electrical connections to, for example, a substrate or an electrical connector. The first contacts12and the second contacts13are preferably aligned with respect to each other in a single row. Aligning the first contacts12and the second contacts13in a single row ensures that the overall transmission length for each of the signals transmitted by the high-speed cable assembly is the same or substantially the same, within manufacturing tolerances. Tie bars14connect the first and second contacts12and13together to provide a rigid structure that structurally supports the first and second contacts12and13during manufacturing and assembling of the high-speed cable assembly. The ground contacts11are connected together by a ground plane15, which includes pilot holes16that provide guidance to stamp the contact ribbon10. Preferably, the first and second contacts12and13are also initially connected to the ground plane15to provide additional structural support during manufacturing and assembling of the high-speed cable assembly. The contact ribbon10preferably includes two rows of ground contacts11, which provide mechanical stability for the connector when it is mounted to a substrate (for example, substrate40as shown inFIGS. 17 and 18). A line extending through the first row of ground contacts11does not intersect with any of the first and second contacts12and13, and a line extending through the second row of ground contacts11does not intersect with any of the first and second contacts12and13.

As shown inFIG. 7, the contact ribbon10can generally include three parallel, spaced apart linear arrays of contacts. A first linear array, row, or column of contacts is positioned immediately adjacent to a second linear array, row, or column of contacts and is spaced apart from the second linear array by a first distance. A third linear array, row, or column of contacts is spaced apart from the second linear array of contacts by a second distance that is greater than the first distance. The second distance can be at least two times the first distance. No contacts are positioned between the first linear array of contacts, between the second linear array of contacts or between the second linear array of contacts and the third linear array of contacts. A first contact of the second linear array and a first contact of the third linear array lie along a first line that is perpendicular or substantially perpendicular within manufacturing tolerances to the second and third linear arrays of contacts. A second contact of the second linear array and a second contact of the third linear array lie along a second line that is perpendicular or substantially perpendicular within manufacturing tolerances to the second and third linear arrays of contacts, parallel to the first line, and spaced apart from the first line. A third contact of the second linear array and a third contact of the third linear array lie along a third line that is perpendicular or substantially perpendicular within manufacturing tolerances to the second and third linear arrays of contacts, parallel to the first and second lines, and spaced apart from the first line and the second line.

Two immediately adjacent first and second contacts of the first linear array are positioned between the first line and the second line, do not touch the first or second lines, and do not overlap the first contacts of the first or second linear arrays or the second contacts of the first or second linear arrays. Two immediately adjacent third and fourth contacts of the first linear array are positioned between the second line and the third line, do not touch the second or third lines, and do not overlap the second contacts of the first or second linear arrays or the third contacts of the first or second linear arrays.

The two immediately adjacent first and second contacts of the first linear array are each spaced apart by a third distance that is less than a fourth distance between two immediately adjacent contacts in the second linear array or between two immediately adjacent contacts in the third linear array. The contacts on the first linear array may be arranged in a first group of two, three, four, five, six, seven etc. evenly spaced pairs of contacts adjacent to a first end of the contact ribbon10, a second group of two, three, four, five, six, seven, etc. evenly spaced pairs of contacts adjacent to a second end of the contact ribbon10, and a distance between the first and second groups that is larger than the first distance. The first contact of the two immediately adjacent first and second contacts of the first linear array and the first contact of the second linear array both lie along a first cross-array line that forms an acute angle with the first line. The acute angle can be 1 to 89 degrees with 45 degrees preferred, the second contact of the two immediately adjacent first and second contacts of the first linear array and the second contact of the second linear array both lie along a second cross-array line that forms an acute angle with the second line. The first linear array can be signal conductors arranged into differential signal pairs, and the second and third linear arrays can be ground shield tails attached to one or more ground shields. The number of contacts in the first linear array is greater than the number of contacts in the second linear array. The number of contacts in the second and third linear arrays can be equal. For example, the first linear array can include sixteen contacts arranged into two groups of differential signal pairs, while the second or third linear arrays can each include ten contacts.

As shown inFIGS. 1 and 2, ground contacts11, the first contacts12, and the second contacts13are preferably included in a ribbon, that is, the contact ribbon10, and arranged such that individual contacts11,12, and13can be formed by cutting the first and second contacts12and13from the ground plane15and removing the tie bars14that connect the first and second contacts12and13. The first and second contacts12and13preferably include a concave portion (not shown) that defines a groove to receive, for example, center conductors of coaxial or twinaxial cables. Preferably, the legs of ground contacts11, first contacts12, and second contacts13include a through-hole (e.g., an “eye-of-the-needle” configuration) to provide an oversize fit for press-fit mounting applications. Accordingly, when the legs are press-fit into corresponding mounting holes in a substrate (for example, substrate40as shown inFIGS. 17 and 18), the legs deform to fit the corresponding mounting holes in the substrate to provide a secure electrical and mechanical connection between the contacts11,12, and13and the substrate. However, other configurations can be used for the legs of ground contacts11, first contacts12, and second contacts13, such as solderable contacts, pogo pins, one-piece contact solutions, two-piece contact solutions, compression contacts, pin and socket contacts, single-beam contacts, dual-beam contacts, multi-beam contacts, elastomeric contacts, directly soldered solutions, crimped contacts, welded contacts, etc. Other configurations that can be used with the preferred embodiments of the present invention include, for example, a square post, a kinked pin, an action pin, a Winchester C-Press® compliant pin, or any other suitable configuration. That is, any contact can be used that is connected to the substrate by heat, plastic deformation, or elastic deformation.

FIGS. 1-16show a process of providing the high-speed cable assembly according to a preferred embodiment of the present invention. As shown inFIGS. 1 and 2, the first and second contacts12and13are cut or stamped so that they are no longer connected to the ground plane15of the contact ribbon10. The number of contacts12and13that are cut preferably corresponds to the number of contacts in the high-speed cable assembly. Preferably, not all of the contacts12and13are cut such that the rigid structure is maintained for the contact ribbon10during assembly and further manufacturing of the high-speed cable assembly. Further, one or more of the first and second contacts12and13can be left connected to the ground plane15to provide additional ground connection(s).

As shown inFIGS. 5-7, the contact ribbon10is inserted into a lower connector housing31, or the lower connector housing31is molded around the contact ribbon10. Preferably, the lower connector housing31is overmolded on the contact ribbon10to form an electrical connector of the high-speed cable assembly. The lower connector housing31is formed with through holes32that are arranged over the tie bars14of the contact ribbon10when the lower connector housing31is molded over the contact ribbon10. As shown inFIGS. 4-7, after overmolding the lower connector housing31on the contact ribbon10, the tie bars14are removed, preferably by a tool punching into the through holes32of the lower connector housing31. Further, the portions of the contact ribbon10that laterally overhang from the lower connector housing31are removed, preferably by cutting or stamping. Accordingly, the first contacts12and the second contacts13are structurally and electrically disconnected from each other and from the ground plane15. Preferably, because the lower connector housing31is overmolded on the contact ribbon10, the lower connector housing31is solid and rigidly supports the connections between the contact ribbon10and the twinaxial cable20. Additionally, the lower connector housing31can include shelf features, retention elements, and/or alignment features that help support the press-in force to retain the contact ribbon10within the lower connector housing31.

During the overmolding of the contact ribbon10, both sides of each contact12,13can be stabilized so that the contacts12,13cannot move while the plastic is being injected around the contacts12,13, which can improve mechanical and electrical performance of the contacts12,13. Stabilizing the contacts12,13can create void cores in the lower connector housing31. These void cores can lower the dielectric constant in the region where the contacts12,13are exposed to air. The void cores can be located where the cable20is attached to the contacts12,13. When the center conductors22,23are soldered to the contacts12,13at the void cores, the air gaps created by the void cores lower the dielectric constant while the solder balances out the local impedance with added capacitance.

Instead of using overmolding for the lower connector housing31, any housing can be used that allows the tie bars14between the first contacts12and second contacts13to be removed. Such housings include, for example, pre-molded, snap-on, sonically welded, screwed-on, and glued housings. However, overmolding is preferred for the lower connector housing31because of its simplicity and because it is easier for a tool to remove the tie bars14. Preferably, the lower connector housing31is made of plastic, for example, acrylonitrile butadiene styrene (ABS) plastic.

As shown inFIGS. 10-14, the contact ribbon10is connected to a twinaxial cable20. Each twinaxial cable20includes a shield21, a first center conductor22, a second center conductor23, an insulator24, and a jacket25. The first and second center conductors22and23are surrounded by the insulator24, the insulator24is surrounded by the shield21, and the shield21is surrounded by the jacket25. For clarity,FIGS. 10-13do not show lower connector housing31.

The shield21and the first and second center conductors22and23are the conductive elements of the twinaxial cable20. The first and second center conductors22and23are arranged to carry electrical signals, whereas the shield21typically provides a ground connection. The shield21also provides electrical isolation for the first and second center conductors22and23and reduces crosstalk between neighboring pairs of the first and second center conductors22and23and between the conductors of any neighboring cables.

The first and second center conductors22and23preferably have cylindrical or substantially cylindrical shapes. However, the first and second center conductors22and23could have rectangular or substantially rectangular shapes or other suitable shapes. The first and second center conductors22and23and the shield21are preferably made of copper. However, the first and second center conductors22and23and the shield21can be made of brass, silver, gold, copper alloy, any highly conductive element that is machinable or manufacturable with a high dimensional tolerance, or any other suitable conductive material. The insulator24is preferably formed of a dielectric material with a constant or substantially constant cross-section to provide constant or substantially constant within manufacturing tolerances electrical properties for the conductors22and23. The insulator24could be made of TEFLON™, FEP (fluorinated ethylene propylene), air-enhanced FEP, TPFE, nylon, combinations thereof, or any other suitable insulating material. The insulator24preferably has a round, oval, rectangular, or square cross-sectional shape, but can be formed or defined in any other suitable shape. The jacket25protects the other layers of the twinaxial cable20and prevents the shield21from coming into contact with other electrical components to significantly reduce or prevent occurrence of an electrical short. The jacket25can be made of the same materials as the insulator24, FEP, or any suitable insulating material.

As shown inFIGS. 10-12 and 14, portions of the first and second center conductors22and23, the insulator24, and the shield21are exposed before the twinaxial cable20is connected to the contact ribbon10. The first and second center conductors22and23are connected to the respective first and second contacts12and13of the contact ribbon10. The first and second center conductors22and23are preferably fusibly connected (for example, by solder) to the first and second contacts12and13to ensure an uninterrupted electrical connection. Preferably, a hot-bar soldering or other soldering technique is used. However, it is possible to use other suitable methods to connect the first and second center conductors22and23to the first and second contacts12and13, e.g., crimping, sonically welding, conductive soldering, convective soldering, inductive soldering, radiation soldering, otherwise melting solder to hold the two parts together, pushing the two parts together with enough force to weld the two parts together, or micro-flaming. Preferably, the shield21is connected with the ground plane15by a hot-bar soldering process, although the shield21and the ground plane15can be connected by other processes, including the process described above with respect to the first and second center conductors22and23and the first and second contacts12and13. The pilot holes16in the ground plane15improve the solder connection between the shield21and the ground plane15by increasing the area through which solder can flow. The connections between the first and second contacts12and13to the first and second center conductors22and23and between the shield21and the ground plane15can occur either simultaneously or successively. In addition, the first and second contacts12and13can be connected to the first and second center conductors22and23and the shield21can be connected to the ground plane15after the lower connector housing31is formed.

Other types of cables, such as coaxial cables, can be used in place of the twinaxial cable20. In addition, the twinaxial cable20can be provided as a ribbonized twinaxial cable, and the ribbonized twinaxial cable can include a single shield that surrounds more than one pair of first and second center conductors22and23.

As shown inFIGS. 8, 9, 15, and 16, an upper connector housing35is preferably attached to the lower connector housing31to form a completed connector. The upper connector housing35protects the components of the completed connector to improve the reliability of the completed connector. In addition, the upper connector housing35can include cosmetic features.

FIG. 17is a cross-sectional view of the completed connector shown inFIGS. 15 and 16mounted to a substrate40. The lower connector housing31and the upper connector housing35are not shown inFIG. 17, for clarity. The ground contact11can be press fit into ground mounting hole41. The mounting hole41can be connected to one or more ground planes in the substrate40. The one or more ground planes can have anti-pads through which mounting holes42,43extend. The contacts12,13(only contact12is visible inFIG. 17) can be press fit into mounting holes42,43(only mounting hole42is visible inFIG. 17). The mounting holes42,43can have annular rings at the surface of the substrate40. The mounting holes42,43can be connected to signal lines in the substrate40. The substrate40can include extra ground vias to reduce loop inductance and to provide extra retention to prevent delamination. Via diameters, via thicknesses, annular rings of the vias, annular-ring thickness, anti-pad geometry, and back-drilling can all be optimized to optimize signal-integrity performance.

FIG. 18is a plan view of the mounting hole layout of the substrate40shown inFIG. 17. Preferably, the completed connector is connected by press-fitting or soldering to the substrates40, according to whether the press-fit or solderable contacts are used. As shown inFIG. 18, the substrate40preferably includes a connector footprint of two rows of ground mounting holes41and a row of alternating first mounting holes42and second mounting holes43. The ground mounting holes41receive the ground contacts11, the first mounting holes receive the first contacts12, and the second mounting holes receive the second contacts13. Preferably, the first mounting holes42and the second mounting holes43are aligned with respect to each other in a single row to correspondingly mate with the first contacts12and the second contacts13. The ground mounting holes41are preferably arranged in first and second rows. A line extending through the first row of ground mounting holes41does not intersect with any of the first mounting holes42and the second mounting holes43, and a line extending through the second row of ground mounting holes41does not intersect with any of the first mounting holes42and the second mounting holes43.

As similarly shown inFIG. 18, the connector footprint can generally include three parallel, spaced apart linear arrays of plated through holes (PTHs) or solder pads. A first linear array, row, or column of PTHs or solder pads is positioned immediately adjacent to a second linear array, row, or column of PTHs or solder pads and is spaced apart from the second linear array by a first distance. A third linear array, row, or column of PTHs or solder pads is spaced apart from the second linear array of PTHs or solder pads by a second distance that is greater than the first distance. The second distance can be at least two times the first distance. No PTHs or solder pads are positioned between the first linear array of PTHs or solder pads, between the second linear array of PTHs or solder pads or between the second linear array of PTHs or solder pads and the third linear array of PTHs or solder pads. A first PTH or solder pad of the second linear array and a first PTH or solder pad of the third linear array lie along a first line that is perpendicular or substantially perpendicular within manufacturing tolerances to the second and third linear arrays of PTHs or solder pads. A second PTH or solder pad of the second linear array and a second PTH or solder pad of the third linear array lie along a second line that is perpendicular or substantially perpendicular within manufacturing tolerances to the second and third linear arrays of PTHs or solder pads, parallel to the first line, and spaced apart from the first line. A third PTH or solder pad of the second linear array and a third PTH or solder pad of the third linear array lie along a third line that is perpendicular or substantially perpendicular within manufacturing tolerances to the second and third linear arrays of PTHs or solder pads, parallel to the first and second lines, and spaced apart from the first line and the second line.

Two immediately adjacent first and second PTHs or solder pads of the first linear array are positioned between the first line and the second line, do not touch the first or second lines, and do not overlap the first PTHs or solder pads of the first or second linear arrays or the second PTHs or solder pads of the first or second linear arrays. Two immediately adjacent third and fourth PTHs or solder pads of the first linear array are positioned between the second line and the third line, do not touch the second or third lines, and do not overlap the second PTHs or solder pads of the first or second linear arrays or the third PTHs or solder pads of the first or second linear arrays.

The two immediately adjacent first and second PTHs or solder pads of the first linear array are each spaced apart by a third distance that is less than a fourth distance between two immediately adjacent PTHs or solder pads in the second linear array or between two immediately adjacent PTHs or solder pads in the third linear array. The PTHs or solder pads on the first linear array may be arranged in a first group of two, three, four, five, six, seven etc. evenly spaced pairs of PTHs or solder pads adjacent to a first end of the connector footprint, a second group of two, three, four, five, six, seven, etc. evenly spaced pairs of PTHs or solder pads adjacent to a second end of the connector footprint, and a distance between the first and second groups that is larger than the first distance. The first PTH or solder pad of the two immediately adjacent first and second PTHs/solder pads of the first linear array and the first PTH or solder pad of the second linear array both lie along a first cross-array line that forms an acute angle with the first line. The acute angle can be 1 to 89 degrees with 45 degrees preferred, the second PTH or solder pad of the two immediately adjacent first and second PTHs/solder pads of the first linear array and the second PTH or solder pad of the second linear array both lie along a second cross-array line that forms an acute angle with the second line. The first linear array can be signal conductors arranged into differential signal pairs, and the second and third linear arrays can be ground shield tails attached to one or more ground shields. The number of PTHs/solder pads in the first linear array is greater than the number of PTHs/solder pads in the second linear array. The number of PTHs/solder pads in the second and third linear arrays can be equal. For example, the first linear array can include sixteen PTHs/solder pads arranged into two groups of differential signal pairs, while the second or third linear arrays can each include ten PTHs/solder pads.

Preferably, the completed connector is press fit to the substrate40using a press-fit tool. The press-fit tool is preferably a simple tool, including, for example, a flat block attached to an arbor press, a tool with a cavity that aligns with the housing, a tap hammer, etc. That is, it is not necessary to use an expensive tool to transfer a force directly and individually to the back of each of the contacts11,12, and13. Typically, the completed connector is only mated to the substrate40once; however, it is possible to unmate the completed connector and the substrate40and then to re-mate the completed connector and the substrate40, if desired. For example, it is possible to remove the press-fit contacts11,12, and13.

According to the preferred embodiments of the present invention, the first contacts12and the second contacts13are offset from ground plane15, as shown inFIGS. 2, 5, 11, 12, and17. This provides a shortened connection between the contacts12and13and the center conductors22and23, due to a very small length of the center conductors22and23being exposed (for example, about 20 mil). Accordingly, a transition region between the twinaxial cable20and the connector is significantly reduced or minimized, which provides high signal integrity for signals transmitted to and from the twinaxial cable20and the substrate40. In particular, the preferred embodiments of the present invention provide a connector with a low return loss, which is a loss of power in a signal due to the signal being at least partially returned or reflected by a discontinuity in the transmission line (e.g., due to an impedance mismatch). In addition, the exposed insulator24of the twinaxial cable20can be used as a reference point for locating the center conductors22and23to the contacts12and13, which simplifies manufacturing of the connector. In this regard, the first contacts12and the second contacts13can also be angled or bent to further improve the connection to the first center conductor22and the second center conductor23of the twinaxial cable.

Also, according to the preferred embodiments of the present invention, the first contacts12and the second contacts13are aligned in a single row, such that the overall length of the transmission for each signal is the same or substantially the same, within manufacturing tolerances. This provides “balanced” contacts with a relatively consistent characteristic impedance and low cross-talk. Preferably, the preferred embodiments of the present invention allow for communication to be performed at about 20 GHz or more, for example. In addition, the center conductors22and23of the twinaxial cable20preferably transmit a differential signal.

According to the preferred embodiments of the present invention, the completed connector can be used to connect the twinaxial cable to different points on the substrate40, or to connect the substrate40to another substrate or to an electronic device. For example, as shown inFIG. 19, one or more twinaxial cables20can be terminated at both ends thereof by a completed connector. The upper connector housing35is not shown for one of the completed connectors inFIG. 19, for clarity.

As another example, in an edge-to-edge application, the substrate40can be connected to a substrate that is co-planar or substantially co-planar and aligned along a common edge. As another example, in a right-angle application, the substrate40can be connected to a substrate that is perpendicular or substantially perpendicular. According to a further example, in a board-to-board application, the substrate40can be connected to a substrate that is parallel or substantially parallel, but not coplanar, for example, when the surfaces of the substrates are facing each other. As yet another example, in a board-to-edge-card application, one end of the completed connector can be connected to a relatively large substrate, such as a computer motherboard, while another end of the completed connector is connected to a relatively small edge-card.

The cable assemblies of the preferred embodiments of the present invention achieve a simulated insertion loss of about −1 dB at frequencies up to and including about 23 GHz and a return loss at or under −20 dB at frequencies up to about 25 GHz. The cable assembly of the preferred embodiments of the present invention achieves power sum far end crosstalk (PSFEXT) of approximately −40 dB at frequencies up to and including 10 GHz. The cable assemblies of the preferred embodiments of the present invention achieve an integrated crosstalk noise (ICN) between 5.6 and 7.5 at a frequency of about 14 GHz for all measured differential pairs. The term “about” refers to measurement tolerances. For example, a frequency of “about 30 GHz” refers to a frequency that is measured to be 30 GHz within measurement tolerances.