WO2021231024A1

WO2021231024A1 - Angled connector including swept contact

Info

Publication number: WO2021231024A1
Application number: PCT/US2021/027587
Authority: WO
Inventors: Daniel R. BIRCH
Original assignee: Samtec, Inc.
Priority date: 2020-05-15
Filing date: 2021-04-16
Publication date: 2021-11-18
Also published as: TW202203508A

Abstract

A connector includes a housing including a conductive material, a base connected to the housing and including a base center hole and a base groove extending from the base center hole to an edge of the base, a center pin including a trunk and a leg extending perpendicular or substantially perpendicular to the trunk, and a protrusion protruding from the leg to provide electrical contact to a pad on a printed circuit board.

Description

ANGLED CONNECTOR INCLUDING SWEPT CONTACT

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63/025,634 filed on May 15, 2020. The entire contents of this application are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0002] The present invention relates to board-mounted connectors. More specifically, the present invention relates to solderless, angled board-mounted coaxial connectors with a non straight contact.

2. Description of the Related Art

[0003] It is known to use a board-mounted connector to connect a coaxial cable to a printed circuit board (PCB). Examples of such connectors are shown in Figs. 1-5. Figs. 1-3 show a male connector with a compression mount. The connector 100 includes a threaded coupling 101 that mates with a corresponding connector of the coaxial cable (not shown) and a flanged base 102 that is mounted to a PCB (not shown) using fasteners through two holes 105, one each located on opposite sides of the base 102. The connector 100 also includes a center pin 104 that connects with a center conductor (not shown) of the coaxial cable and with a pad or a trace on the PCB. The base 102 can include an opening 106 in one side that is one end of a slot or groove that extends to the center pin 104 through which a trace can be routed on the top surface of the PCB.

[0004] Figs. 2 and 3 are views of the side of the connector 100 including the opening 106 shown in Fig. 1. Fig. 3 is an expanded view of area A shown in Fig. 2. The PCB side of the center pin 104 is visible through the opening 106. As shown, a portion of the bottom surface of the base 102 is raised and is used as a pad 107 to ground the connector 100 and to mate with a grounding pad located on the PCB. Dimension arrows B in Fig. 2 indicate the total height of the base 102 including the pad 107. The thickness of the pad 107 from the bottom surface of the base 102 is indicated by dimension arrows C in Fig. 3. Fig. 3 also shows that the center pin 104 extends farther than the pad 107 as indicated by dimension arrows D. When the connector 100 is attached to a PCB, the connector 100 is oriented to align the mounting holes 105 to corresponding holes in the PCB and to align the opening 106 over an exposed trace on the surface of the PCB. This orientation will align the center pin 104 to a pad on the PCB at the end of the trace, and the extended portion of the center pin 104 will contact the pad when the mounting fasteners are tightened to securely flush mount the bottom of the base 102 to the PCB. When the connector 100 is securely mounted, the center pin 104 will slightly compress and press into the pad on the PCB to generate a physical and electrical connection between the center pin 104 and the pad on PCB. The connection between the center conductor of the coaxial cable, the center pin 104 of the connector 100, the pad, and the trace, allows signals to be transmitted and received between the PCB and the coaxial cable.

[0005] Figs. 4 and 5 show sectioned views of a coaxial connector 400. This style of connector 400 is surface mounted to a PCB 420. As shown, the connector 400 includes a housing 401, a flanged base 402, a J- or L-shaped center pin 404, a dielectric insert 403 used to electrically isolate the center pin 404 from the housing 401, and legs 410 that are used to align and mount the connector 400 to the PCB 420. The base 402 or the legs 410 are soldered to the PCB 420.

[0006] As shown in Figs. 4 and 5, the dielectric 403 is arranged in the bottom of the base 402 that surrounds the center pin 404. The center pin 404 can include a first portion that extends along the central axis of the housing 401 and a second portion that is perpendicular to the first portion and that extends parallel to the surface of the PCB 420. The legs 410 can be grounded when the connector 400 is mounted to the PCB 420. In this case, the legs 410 are inserted into through holes in the PCB 420 and are connected to ground in or on the PCB 420. The first portion of the center pin 404 connects with a center conductor of the coaxial cable and the second portion is soldered to a pad on the PCB 420 to achieve electrical contact to the PCB 420.

[0007] A coaxial cable has a center conductor that is surrounded by a dielectric that is surrounded by an outer shield. The shield provides a conductive surface that shields transmitted signals and defines the outer boundary of the transmission line. Transmitted signals in the dielectric couple from the center conductor to the shield's inner conductive surface. To maintain signal integrity, mating connectors attempt to approximate or mirror the coaxial structure of the coaxial cable. However, the connectors 100, 400 inexactly approximate this coaxial structure (i.e., a conductor that is surrounded by a dielectric that is surrounded by a shield). The housings 101, 401 of the connectors 100, 400 are typically made of a conductive material and correspond to the shield of the coaxial cable. The center pins 104, 404 are also typically made of a conductive material and correspond to the center conductor of the coaxial cable. The dielectric 403 is made of a dielectric material and corresponds to the dielectric in the coaxial cable.

[0008] High-speed signals act like guided waves. A uniform guiding system from beginning to end with no abrupt changes in geometry or impedance is ideal. One of the problems with the connector 100 is that the junction where the center pin 104 press-contacts the pad and trace on the PCB is a 90° angle that causes an abrupt change in the signal transmission path geometry and in the electrical impedance. The signal transmitted by the portion of the center pin 104 extending along the PCB couples with the closest conductive surface, which is the flat inside surface of the base 102, and thus the structure is no longer coaxial. When the connector 100 is mated with a coaxial cable, the signals transmitted between the connector 100 and the coaxial cable experience this abrupt change in the coaxial structure.

[0009] The connector 400 has better electrical performance than the connector 100 in that the 90° bend of center pin 404 is sweeping and not as abrupt. This allows for a gentler turn in the signal transmission. However, the portion of the center pin 404 extending parallel to the PCB must be long enough to exit the base 402 and allow for an adequate solder connection to a pad on the PCB. The soldered center pin 404 impairs impedance matching.

[0010] Because the connectors 100, 400 inexactly approximate the coaxial structure, signals transmitted through the PCB and the coaxial cable experience an impedance mismatch when the signals are transmitted through the connector 100, 400. This impedance mismatch decreases performance with higher frequencies. The larger the impedance mismatch, the worse the signal integrity. [0011] Known techniques to improve signal integrity focus on providing the best possible uniform wave guiding system, which is sometimes referred to as the transmission line. A fundamental parameter used to define a uniform guiding system is the characteristic impedance (Z₀). High-frequency data transmission allows characteristic impedance Z₀ to be defined as the square root of the ratio of inductance L to capacitance C (i.e., Zo = V(L/C)). The inductance and capacitance values are determined by the material properties and geometrical dimensions of the finite length of section of the guiding system. The known technique of impedance matching uses the material properties and geometrical dimensions of different sections of the wave guiding system to provide capacitance and inductance changing schemes to attempt to achieve the most overall uniform wave guiding system from start to finish. [0012] Impedance matching for wave guide systems encompass many components, including connector design and materials, PCB design, interface and interconnection methodology.

SUMMARY OF THE INVENTION

[0013] To overcome the problems described above, embodiments of the present invention provide compression-mounted, angled connectors with non-straight center pins and with improved electrical performance and improved coaxial structure.

[0014] A connector according to an embodiment of the present invention includes a housing including a conductive material, a base connected to the housing and including a base center hole and a base groove extending from the base center hole to an edge of the base, a center pin including a trunk and a leg extending perpendicular or substantially perpendicular to the trunk, and a protrusion protruding from the leg to provide electrical contact to a pad on a printed circuit board.

[0015] The connector can further include a center bead extending through the base center hole and including a center hole through which the trunk of the center pin extends; and an end bead extending perpendicular or substantially perpendicular to the center bead along the base groove and including a center hole along which the leg of the center pin extends.

[0016] A cross section of the leg and the protrusion can be asymmetric. A radius of the leg at the protrusion can be larger than a radius of the leg not at the protrusion. The protrusion can be a rib in which a height of the rib increases as the leg extends away from the base. The base can include three mounting holes or can include only two mounting holes.

[0017] A connector assembly according to an embodiment of the present invention includes a connector including a housing including a conductive material, a base connected to the housing and including a base center hole and a base groove extending from the base center hole to an edge of the base, and a center pin including a trunk and a leg extending perpendicular or substantially perpendicular to the trunk, and a pad on a printed circuit board, wherein a thickness of the pad extends from a top surface of the printed circuit board to provide electrical contact to the leg.

[0018] The pad can include a bump.

[0019] A compression-mounted coaxial connector according to an embodiment of the present invention includes a center pin with a J-shape.

[0020] The center pin can include a 90° bend. The center pin can include a trunk and a leg that are connected by a bend, and the leg can be asymmetric about a horizontal plane extending through a center of the leg and along the length of the leg. The center pin can include a protrusion. The protrusion can be a rib with a height that can increase toward an end of the center pin.

[0021] A coaxial connector according to an embodiment of the present invention includes a center pin and fasteners, wherein, when fasteners attach the coaxial connector to a substrate, the fasteners are arranged such that a line through any two of the fasteners does not intersect with an end of the center pin that is connected to the substrate.

[0022] The center pin can be J-shaped. The center pin can include a 90° bend. The center pin can include a trunk and a leg that are connected by a bend, and the leg can be asymmetric about a horizontal plane extending through a center of the leg and along the length of the leg. The center pin can include a protrusion. The protrusion can be a rib with a height that can increase towards an end of the center pin.

[0023] A coaxial connector according to an embodiment of the present invention includes a center pin with a trunk and a leg connected by a bend, wherein the leg is asymmetric about a horizontal plane extending through a center of the leg and along the length of the leg. [0024] The center pin can be J-shaped. The bend can be a 90° bend. The center pin can include a protrusion. The protrusion can be a rib with a height that can increase toward an end of the center pin.

[0025] A system according to an embodiment of the present invention includes a substrate with a pad, a coaxial connector that is compression mounted to the substrate and that includes a center pin, and a bridge connecting the pad and the center pin.

[0026] The bridge can be a protrusion on the center pin. The protrusion can be a rib with a height that can increase toward an end of the center pin. The bridge can be a pad extension on the pad or can be a bump. The center pin can be J-shaped. The center pin can include a 90° bend.

[0027] The above and other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS [0028] Figs. 1-3 are views of a first connector of the related art.

[0029] Figs. 4 and 5 are views of a second connector of the related art.

[0030] Figs. 6 and 7 are perspective views of a connector connected to a substrate with a compression mount.

[0031] Fig. 8 is an exploded view of the connector of Fig. 6.

[0032] Fig. 9 is a side sectioned view of the connector of Fig. 6.

[0033] Figs. 10 and 11 are close-up views of the connector of Fig. 6.

[0034] Figs. 12 and 13 are perspective views of the housing and base of the connector of

Fig. 6.

[0035] Figs. 14 and 15 are perspective views of a bushing of the connector of Fig. 6.

[0036] Figs. 16 and 17 are perspective views of a center pin of the connector of Fig. 6.

[0037] Fig. 18 is a perspective view of a center bead of the connector of Fig. 6.

[0038] Figs. 19 and 20 are perspective views of an end bead of the connector of Fig. 6.

[0039] Fig. 21 is a perspective view of a portion of a substrate on which the connector of

Fig. 6 can be mounted. DETAILED DESCRIPTION

[0040] Figs. 6-11 show a connector 60, Figs. 12-20 show components of the connector 60, and Fig. 21 shows a portion of a substrate 70 that can be used with the connector 60.

[0041] As shown in the perspective views in Figs. 6 and 7, the exploded view in Fig. 8, and the side section view of Fig. 9, the connector 60 includes a housing 61 that mates with a corresponding connector of a coaxial cable (not shown) and a base 62 that can be mounted to a substrate 70 using fasteners 75. The connector 60 also includes a J- or L-shaped center pin 64 that connects with a center conductor of the coaxial cable and with a pad and trace on the substrate 70. The connection between the center conductor of the coaxial cable, the center pin 64 of the connector 60, and the pad and trace of the substrate 70 allows signals to be transmitted and received between the substrate 70 and the coaxial cable.

[0042] The connector 60 also includes a bushing 63, a center bead 65, and an end bead 66. The center bead 65 is a dielectric that fits around the center pin 64 to centrally locate the center pin 64 in the connector 60 and electrically isolate the center pin 64 from the housing 61. The center bead 65 can be attached to the center pin 64 at a location in which the center pin 64 has a reduced diameter to prevent movement of the center pin 64 both in a radial direction and an axial direction of the housing. In addition to locating the center pin 64 within the housing 61, the center bead 65 is also used to improve or optimize impedance of the connector 60. The end bead 66 is a dielectric arranged in the bottom of the base 62 that fits over the center pin 64 to centrally locate the center pin 64 in an opening in the base 62 and electrically isolate the center pin 64 from the base 62.

[0043] Alternatively, it is possible to combine the center bead 65 and the end bead 66 into a single dielectric bead. This would require changing the interior geometry of the housing 61 and the base 62 and the configuration of the center pin 64 to reduce parasitic capacitance between the center pin 64 and the conductive housing 61 and 62 to balance impedance. As shown in Fig. 9, the center pin 64 can include narrower and wider portions to prevent the center pin 64 from moving up and down and to optimize impedance. Features including air gaps and spacing between portions of the center pin 64, the housing 61, the base 62, and the single piece dielectric would need to be considered together to achieve the goal of maintaining a constant impedance throughout the connector.

[0044] The bushing 63 is force fit or friction fit into the housing 61 and used to retain the center bead 65 and the center pin 64 in the housing 61. The end bead 66 can also be force fit or friction fit into the base 62, but the end bead 66 can be retained within the opening of the base 62 in any suitable manner. For example, the center pin 64 can be used to retain the end bead 66. Slight deformations, such as staking or coining the radius of the opening or the groove in the base 62, can be used to retain the end bead 66. An adhesive can be used to retain the end bead 66 in the base 62.

[0045] The housing 61 includes threads used to connect to a corresponding threaded collar on a mating connector at the end of the coaxial cable. However, other connections types are possible including a push fitting, a BNC (bayonet), snap-on, F-type, PAL (phase alternating lines), and the like.

[0046] As shown in Figs. 6 and 7, the connector 60 can be mounted to the substrate 70 using fasteners 75 that are inserted through mounting holes in the substrate 70 and screwed into corresponding threaded holes in the base 62. Although the fasteners 75 are depicted as screws, other types of fasteners can be used such as nuts and bolts, rivets, and the like. Although three fasteners 75 are shown, other numbers of fasteners are possible. The center pin 64 can be pushed into contact with the pad 72 on the substrate 70 with or without deformation when the fasteners 75 are tightened to mount the bottom of the base 62 to the substrate. If the center pin 64 includes a 90° bend, then the center pin 64 can be pushed into contact with the pad 72 on the substrate 70 without deformation. But if the center pin 64 has a bend of less than 90°, e.g., a bend of 80° or 85°, then the center pin 64 can be pushed into contact with the pad 72 on the substrate 70 with deformation. The fasteners 75 can be arranged such that a line through any two of the fasteners 75 does not intersect with the end of the center pin 64 that connects with the substrate 70. Instead of using fasteners 75, the connector 60 can be compression-mounted to the substrate 70 in any suitable manner.

[0047] The substrate 70 can be a PCB or any other suitable substrate. [0048] The connector 60 includes a groove in the base 62 that provides a close conductive surface that signals transmitted through the center pin 64 can couple to, approximating a coaxial structure between the center pin 64 and the interior surface of the connector 60. The connector 60 is hollow within the housing 61 and the bushing 63 extending along a central axis of the connector 60. The center bead 65 can include a dielectric material that is located within the housing 61. The radius of the interior of the housing 61 is such that the center bead 65 can provide the same or substantially the same within manufacturing tolerances impedance as the impedance of the coaxial cable. This structure allows for the coaxial structure of the coaxial cable to extend into the connector 60. The interior of the connector 60 includes a groove that extends along the bottom of the base 62 to the edge of the base 62. The end bead 66 can include a dielectric material that is located within the groove of the housing 61. The cross- sectional shape of the groove can be a truncated circle, but other cross-sectional shapes are also possible. The cross-sectional shape of the groove can approximate a semicircle but will be larger than a semicircle to accommodate the center pin 64. The radius of a portion of the groove can be the same or substantially the same within manufacturing tolerances as the radius of a portion of the interior of the housing 61. This allows for the coaxial structure of the coaxial cable to be approximated within the connector 60 parallel or substantially parallel to the surface of the substrate 70 where the substrate 70 approximates half of the coaxial structure.

[0049] The connector 60 more closely approximates the coaxial structure of the coaxial cable compared to connector 100 of the related art because of the swept center pin 64 geometry. The connector 60 more closely approximates the coaxial structure of the coaxial cable compared to connector 400 of the related art because the interface of the center pin 64 to the substrate 70 does not require a solder connection as the solder connection causes an issue with impedance matching. That is, the connection of the center pin 64 to the substrate 70 can be made by compression without soldering, welding, bonding, or adhering the center pin 64 to the substrate 70.

[0050] It is possible to provide tilted connectors with center pins 64 that have a bend other than 90°. In a tilted connector, the housing 61 can be tilted with respect to the base 62. For example, instead of the connector 60 being a vertical connector as shown in Figs. 12 and 13, the connector 60 can be a 45° connector with the housing 61 tilted at an angle of 45° with respect to the base. As with the vertical connector, the bend in the center pin 64 does not have to exactly match the bend in the connector 60. For example, in a 45° connector, the bend in the center pin 64 could be 35° or 40°, which could increase the amount of normal force applied to the pad on the substrate when the connector is mounted to the substrate.

[0051] Figs. 10 and 11 are close-up views showing the center pin 64 extending from the side of the base 62 and contacts the substrate 70. Alternatively, the center pin 64 can be shorter such that it does not extend outside of the edge of the base 62. Alternatively, the base 62 need not include an opening. Alternatively, the end bead 66 can cover the center pin 64 such that the center pin 64 is not visible when the connector 60 is mounted to the substrate 70.

[0052] The substrate 70 is shown as an exemplary cut-out of a larger structure and included to show a pad 72 in contact with the center pin 64. Figs. 10 and 11 show portions of the base 62, the center pin 64, the substrate 70, and the pad 72. Portions of the end bead 66 and a fastener 75 are visible in Fig. 10. The center pin 64 includes a trunk 644 that extends through the interior of the housing 61 and a leg 642 that extends through the groove in the housing 61. The trunk 644 and the leg 642 can define a J- or L-shape. Other shapes are possible if the connector 60 is at an angle other than 90°. The leg 642 of the center pin 64 can be a cylinder both in the groove of the housing 61 and where the center pin 64 exits the base 62, and a protrusion 643 or rib that protrudes outwardly from the leg 642 at the end of the center pin 64. The end bead 66 can be located near the end of the center pin 64 that contacts the pad 72 on the substrate 70 to help maintain the coaxial structure. The center pin 64 is oriented such that the protrusion 643 contacts the pad 72 when the connector 60 is mounted to the substrate 70 and the bottom surface of the base 62 is securely in contact with the top surface of the substrate 70 after the fasteners 75 have been tightened. Because the protrusion 643 provides physical and electrical connection between the center pin 64 and the pad 72 by compression, solder or another conductive material in this area is not required. By locating the protrusion 643 at the end of the center pin 64, unwanted resonances can be reduced or eliminated. The geometric relationships between the leg 642, the protrusion 643, the pad 72, and the trace layout can be optimized to maximize electrical performance by minimizing impedance mismatching, signal reflection, and resonance.

[0053] Figs. 12-20 show the various components that make up the connector 60. Figs. 12 and 13 are different perspective views of the housing 61 and the base 62. The housing 61 is substantially a hollow cylinder and, as previously mentioned, includes threads 611 on the outside. It is also possible that the housing 61 includes structures other than threads to connect the housing 61 to a coaxial cable. The base 62 can be flanged with respect to the housing 61. The housing 61 and the base 62 can be fabricated as separate components and assembled together or made as one component. Although the housing 61 is shown as being oriented about a 90° angle with respect to the flange of the base 62, other angles are possible. Both the housing 61 and base 62 can be made of a metal, a metal alloy, or any other suitable material. [0054] The base 62 can be substantially disk shaped with flat top and bottom surfaces and one flat portion 621 at a substantially circular outer surface 622. The base 62 can include three mounting holes 623 used to mount the connector 60 to the substrate 70. As mentioned, the mounting holes 623 shown are tapped to include threads to match screw fasteners. Alternatively, the mounting holes 623 can be smooth bored. Any number of mounting holes 623 can be used to secure the connector 60 to the substrate 70. However, it is important that the mounting technique exhibit suitable and balanced forces such that the center pin 64 maintains compression contact with the pad 72 on the substrate 70 once the connector 60 is fully assembled to the substrate 70. Alternatively, the base can include only two mounting holes 623.

[0055] The flat portion 621 of the base 62 includes an opening 624 that is one end of a groove 625 that extends to about the center of the base 62. The groove 625 provides a space in which to install and route the center pin 64. As shown in Fig. 12, the groove 625 can include walls with different radiuses used to retain the center pin 64 and/or the end bead 66. The housing 61 and the base 62 can be made of a metal, a metal alloy, or any other suitable material.

[0056] Figs. 14 and 15 are different perspective views of the bushing 63. The bushing 63 is hollow and substantially cylindrically shaped. The bushing 63 can be press fit into the housing 61 and used to retain the center bead 65 and the center pin 64. The bushing 63 can include portions with different interior and exterior diameters that match with corresponding features of the housing 61 and the center bead 65. The bushing 63 can be made of a metal, a metal alloy, or any other suitable material.

[0057] Figs. 16 is a perspective view of the J- or L-shaped center pin 64, and Fig. 17 is a close-up view of the leg 642. The center pin 64 includes a trunk 644 and a leg 642. As shown in Fig. 16, the trunk 644 and the leg 642 can be connected by a 90° bend. It is possible that the trunk 644 and the leg 642 can be connected by bends other than 90° degrees. For example, if a bend of 80° or 85° is used, then the amount of normal force applied from the center pin 64 to the pad on the substrate can be increased. Alternately, the center pin 64 can be any angle suitable to match with an angle of the connector 60. The center pin 64 can include a contact cup 641 used to mate with a corresponding portion of the coaxial cable. As shown, the contact cup 641 can be substantially cylindrical with four tangs around a hollow center. The hollow center is designed to accept a center conductor of the coaxial cable with the tangs providing spring tension on the sides of the center conductor once inserted into the hollow center. The contact cup 641 can be arranged to mate with other male and female coaxial cable conductor geometries.

[0058] The trunk 644 of the center pin 64 can include different diameters used to mate with and assist in retaining the center pin 64 within the center bead 65. These structural features can also be used to electrically tune the center pin 64. The center pin 64 can be made from beryllium copper or any other suitable material.

[0059] The leg 642 is constructed to be solid, substantially cylindrical but asymmetric about a horizontal plane extending through the center of the leg 642 and along the length of the leg 642 with the protrusion 643 at the tip of the leg 642. As shown in Fig. 17, the protrusion 643 is a rib included in a relatively small portion of the overall circumference of the leg 642. The height of the protrusion 643 gradually increases from where it begins to protrude from the leg 642 to a maximum height where the protrusion 643 terminates at the tip of the leg 642. The vertical axis of the protrusion 643 is perpendicular or substantially perpendicular within manufacturing tolerances to the longitudinal axis of the leg 642 and parallel or substantially parallel within manufacturing tolerances to the longitudinal axis of the trunk 644. The maximum cross section of the leg 642 at the protrusion 643 is slightly greater than the distance between the leg 642 without the protrusion 643 and the pad 72 on the substrate 70, which allows the protrusion 643 to bridge the gap between the leg 642 and the pad 72 so that the protrusion 643 makes physical and electrical contact with the pad 72. Because the maximum height of the protrusion 643 is greater than the distance between the leg 642 and the pad 72, the protrusion 643 will be pressed against the pad 72 once the connector 60 is fully attached to the substrate 70, causing deformation and spring tension in the leg 642. This bending of the leg

642 causes no deformation at the contact cup 641 because the center pin 64 is rigidly retained in the housing 61.

[0060] Although the protrusion 643 is shown as a triangularly shaped rib, other shapes are possible. The size and shape of the protrusion 643 can be tailored to specific applications and improve electrical performance. Alternatively, the protrusion 643 can be any shape that provides an adequate contact point with an underlying pad 72 and can include, but is not limited to, a hemisphere, a cone, a cone with a rounded tip, a truncated cone, a rounded tip, a flat tip, a small-ball tip, a flare or taper, mushroom shaped, trapezoid, and the like. The protrusion can extend around the center pin 64 in the circumferential direction either fully or partially. For example, if the protrusion 643 extends around the full circumference of the center pin 64, then the protrusion can define a nail-head shape. Alternatively, the protrusion 643 can be added as a separate component to the center pin 64 such as with a collar or ring over the center pin 64 or inserted into a groove or hole in the center pin 64. Alternatively, the protrusion

643 can protrude from the end surface of the center pin 64 rather than a side surface. It is also possible that the center pin 64 is a metal stamping and that the cross section of the center pin 64 has a shape other than that of a circle, including, for example, triangle, square, pentagon, hexagon, etc.

[0061] The protrusion 643 can be located about 0.010" from the end of the center pin 64. A height of the protrusion 643 can be about 0.010" or less. The contact area where the protrusion 643 contacts the pad 72 can be a radius of about 0.002", an area of about 0.000025 in², or about 20% of the radius of the center pin 64. The sharper or more pointed the protrusion, the easier the protrusion can break any oxides located on the pad 72.

[0062] Fig. 18 is a perspective view of the center bead 65. The center bead 65 can be a symmetric mechanically compliant dielectric and can be made of any suitable material. The center bead 65 can be substantially disk shaped to fit with the cylindrical housing 61 and the bushing 63. The center bead 65 can include a center hole 651, several though holes 652, and a slot 653. The center hole 651 is an opening through the longitudinal axis of the center bead 65 that extends entirely through the thickness of the center bead 65 with a diameter to fit around and retain the center pin 64. The slot 653 extends through the entire radius of the center bead 65 such that the thickness of the slot 653 can be expanded and passed over the center pin 64 to locate the center pin 64 in the center hole 651. Like the center hole 651, the through holes 652 can extend entirely through the center bead 65. Although six through holes 652 are shown, other numbers of through holes are possible. The diameter and the number of through holes 652 can be predetermined to electrically tune the dielectric characteristics of the center bead 65 to the connector 60.

[0063] Figs. 19 and 20 are perspective views of the end bead 66. The end bead 66 can be a mechanically compliant dielectric and can be made of any suitable dielectric material. The shape of cross-section of the end bead 66 can be a truncated circle to fit within the groove 625 of the housing 61 and can include a hole 661 and a slot 662. The hole 651 is an opening on the longitudinal axis that extends entirely through the thickness of the end bead 66 with a diameter to fit around and retain the leg 642 of the center pin 64. The slot 662 extends through the entire radius of the end bead 66 such that the thickness of the slot 662 can be expanded and passed over the leg 642 to locate the leg 642 in the hole 661. The end bead 66 can be used to control the clocking of the leg of the center pin, i.e., the angle of the leg of the center pin with respect to the substrate. For example, if the center pin includes an angle that is not 90°, then the slot 662 can be used to control the clocking of the center pin as the connector is mounted to the substrate. As previously mentioned, the center bead 65 and the end bead 66 can be made as a single one-piece structure. [0064] Fig. 21 is a perspective view of a portion of the substrate 70. The substrate 70 can be made of FR-4, G-10, or any other suitable material. As shown, the substrate 70 includes three through holes 71 and a pad 72. The geometry and relationship of the through holes 71 match those of the mounting holes 623 in the base 62 to allow the fasteners 75 to pass through. The pad 72 is on the top surface of the substrate 70 and used to connect the leg 642 of the center pin 64 to traces in the substrate 70. The pad 72 can be connected to a microstrip on or in the substrate 70, which extends the coaxial structure into the substrate. Although not shown in Fig. 21, the pad 72 can be located in a groove in the substrate. Alternatively, the substrate 70 can include a groove in which just the connector 60 is located or in which both the pad 72 and the connector 60 are located. The substrate 70 can also include one or more holes through which one or more portions of the housing 61 are located to extend coaxial structure into the substrate 70. The pad 72 can be made of conventional materials using conventional PCB processing techniques. The thickness of the pad 72 can be increased to extend above the top surface of the substrate 70 such that the pad 72 partially or entirely bridges the gap between the substrate 70 and the leg 642. A bump (e.g., a gold bump) can be included on top of the pad 70 such that the bump partially or entirely bridges the gap between the substrate 70 and the leg 642. The thicker pad and/or the bump can be used instead of or in combination with the protrusion 643 on the leg 642. Although not shown in Fig. 21, the substrate can have a C- shaped pad that matches the bottom of the base 62 to ground the housing 61.

[0065] The connector 60 can be a radio-frequency (RF) connector and can be made in any suitable manner and can be made of any suitable material so long as the connector 60 provides a close conductive surface to which the signals can couple to. For example, the connector 60 can operate at about 40-110 GHz including, for example, up to 70 GHz, up to 80 GHz, up to 90 GHz, up to 100 GHz, and up to 110 GHz. Alternatively, the connector 60 can operate up to 125 GHz. Instead of having a vertical arrangement as shown in the figures discussed above, the connector 60 can have a right-angle arrangement in which the coaxial cable connected to the connector 60 would extend parallel to the surface of the substrate 70. Alternatively, the connector 60 can be arranged at about 45°, 135°, or any other suitable angle. The housing 61, the bushing 63, and the center bead 65 of the connector 60 are not limited to the circular horizontal cross-section as shown in the figures above. The horizontal cross-section of the housing 61 and bushing 63 could be, for example, a square, an octagon, or any other suitable shape.

[0066] The center bead 65 and the end bead 66 dielectrics can be made in any suitable manner and can be made of any suitable dielectric material. The dielectrics can be a single continuous piece or can be multiple discrete pieces. The center pin 64 can be made in any suitable manner and can be made of any suitable conductive material. For example, the center pin 64 can be milled and then bent to form the J- or L-shape or at another suitable angle.

[0067] It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variances that fall within the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A connector comprising: a housing including a conductive material; a base connected to the housing and including a base center hole and a base groove extending from the base center hole to an edge of the base; a center pin including a trunk and a leg extending perpendicular or substantially perpendicular to the trunk; and a protrusion protruding from the leg to provide electrical contact to a pad on a printed circuit board.

2. The connector of claim 1, further comprising: a center bead extending through the base center hole and including a center hole through which the trunk of the center pin extends; and an end bead extending perpendicular or substantially perpendicular to the center bead along the base groove and including a center hole along which the leg of the center pin extends.

3. The connector of claims 1 or 2, wherein a cross section of the leg and the protrusion is asymmetric.

4. The connector of claims 1 or 2, wherein a radius of the leg at the protrusion is larger than a radius of the leg not at the protrusion.

5. The connector of any of the claims 1-4, wherein the protrusion is a rib in which a height of the rib increases as the leg extends away from the base.

6. The connector of any of the claims 1-5, wherein the base includes three mounting holes.

7. The connector of any of the claims 1-5, wherein the base includes only two mounting holes.

8. A connector assembly comprising: a connector including: a housing including a conductive material; a base connected to the housing and including a base center hole and a base groove extending from the base center hole to an edge of the base; and a center pin including a trunk and a leg extending perpendicular or substantially perpendicular to the trunk; and a pad on a printed circuit board, wherein a thickness of the pad extends from a top surface of the printed circuit board to provide electrical contact to the leg.

9. The connector assembly according to claim 8, wherein the pad includes a bump.

10. A compression-mounted coaxial connector including a center pin with a J-shape.

11. The compression-mounted coaxial connector of claim 10, wherein the center pin includes a 90° bend.

12. The compression-mounted coaxial connector of claim 10, wherein the center pin includes a trunk and a leg that are connected by a bend; and the leg is asymmetric about a horizontal plane extending through a center of the leg and along a length of the leg.

13. The compression-mounted coaxial connector of one of claims 10-12, wherein the center pin includes a protrusion.

14. The compression-mounted coaxial connector of claim 13, wherein the protrusion is a rib with a height that increases toward an end of the center pin.

15. A coaxial connector comprising a center pin and fasteners, wherein, when fasteners attach the coaxial connector to a substrate, the fasteners are arranged such that a line through any two of the fasteners does not intersect with an end of the center pin that is connected to the substrate.

16. The coaxial connector of claim 15, wherein the center pin is J-shaped.

17. The coaxial connector of claim 15 or 16, wherein the center pin includes a 90° bend.

18. The coaxial connector of claim 15 or 16, wherein the center pin includes a trunk and a leg that are connected by a bend; and the leg is asymmetric about a horizontal plane extending through a center of the leg and along a length of the leg.

19. The coaxial connector of one of claims 15-18, wherein the center pin includes a protrusion.

20. The coaxial connector of claim 15, wherein the protrusion is a rib with a height that increases toward an end of the center pin.

21. A coaxial connector comprising a center pin with a trunk and a leg connected by a bend, wherein the leg is asymmetric about a horizontal plane extending through a center of the leg and along a length of the leg.

22. The coaxial connector of claim 21, wherein the center pin is J-shaped.

23. The coaxial connector of claim 21 or 22, wherein the bend is a 90° bend.

24. The coaxial connector of one of claims 21-23, wherein the center pin includes a protrusion.

25. The coaxial connector of claim 24, wherein the protrusion is a rib with a height that increases toward an end of the center pin.

26. A system comprising: a substrate with a pad; a coaxial connector that is compression mounted to the substrate and that includes a center pin; and a bridge connecting the pad and the center pin.

27. The system of claim 26, wherein the bridge is a protrusion on the center pin.

28. The system of claim 27, wherein the protrusion is a rib with a height that increases toward an end of the center pin.

29. The system of claim 26, wherein the bridge is a pad extension on the pad or is a bump.

30. The system of one of claims 26-29, wherein the center pin is J-shaped.

31. The system of one of claims 26-30, wherein the center pin includes a 90° bend.