Flexible shield and electrical connector

Abstract

The present disclosure relates to flexible shields and electrical connectors. In one embodiment, a flexible shield for an electrical connector is involved. The electrical connector includes a plurality of contact tails for attachment to a printed circuit board. The flexible shield includes a matrix material, a plurality of openings extending through the matrix material, the plurality of openings being sized and positioned for passage of the contact tails from the electrical connector therethrough, and a conductive coating on the matrix material, wherein: the conductive coating is configured to provide a current flow path between the shield inside the electrical connector and a ground structure of the printed circuit board.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application number 201780073986.7 (PCT / US2017 / 057402), application date October 19, 2017, and invention name “Flexible shielding for ultra-high-speed high-density electrical interconnection”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This patent application claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 62 / 410,004, filed on October 19, 2016, entitled “Compliant Shield for Very High Speed, High Density Electrical Interconnection,” which is hereby incorporated by reference in its entirety. This patent application also claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 62 / 468,251, filed on March 7, 2017, entitled “Compliant Shield for Very High Speed, High Density Electrical Interconnection,” which is hereby incorporated by reference in its entirety. This patent application also claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 62 / 525,332, filed on June 27, 2017, entitled “Compliant Shield for Very High Speed, High Density Electrical Interconnection,” which is hereby incorporated by reference in its entirety. Technical Field

[0004] The present patent application relates generally to interconnection systems for interconnecting electronic components, such as interconnection systems including electrical connectors. Background Art

[0005] Electrical connectors are used in many electronic systems. It is often easier and more cost-effective to manufacture the system as separate electronic components, such as printed circuit boards ("PCBs"), that can be joined together with electrical connectors. A known arrangement for joining several printed circuit boards is to have one printed circuit board serving as a backplane. Other printed circuit boards, known as "daughterboards" or "daughter cards," can be connected via the backplane.

[0006] A known backplane is a printed circuit board (PCB) on which a number of connectors may be mounted. Conductive traces in the backplane can be electrically connected to signal conductors in the connectors, allowing signals to be routed between the connectors. Daughter cards may also have connectors mounted thereon. The connectors mounted on the daughter cards can be plugged into connectors mounted on the backplane. In this way, signals can be routed between the daughter cards through the backplane. The daughter cards can be plugged into the backplane at right angles. Consequently, connectors used for these applications include right-angle bends and are often referred to as "right-angle connectors."

[0007] In other configurations, connectors can also be used to interconnect printed circuit boards and other types of devices, such as cables, with printed circuit boards. Sometimes, one or more smaller printed circuit boards can be connected to another larger printed circuit board. In such a configuration, the larger printed circuit board can be called a "motherboard" and the printed circuit board connected to the motherboard can be called a daughterboard. In addition, printed circuit boards of the same or similar size can sometimes be aligned in parallel. Connectors used in these applications are often referred to as "stacking connectors" or "mezzanine connectors."

[0008] Regardless of the specific application, the design of electrical connectors reflects trends in the electronics industry. Electronic systems are generally becoming smaller, faster, and more complex. As a result of these changes, the number of circuits in a given area of ​​an electronic system, as well as the frequency at which these circuits operate, has increased significantly in recent years. Current systems transfer more data between printed circuit boards, requiring electrical connectors that can handle more data at higher speeds than connectors of just a few years ago.

[0009] In high-density, high-speed connectors, electrical conductors can be located close together, potentially causing electrical interference between adjacent signal conductors. To reduce this interference or provide desired electrical properties, shielding members are often placed between or around adjacent signal conductors. Shielding can prevent signals carried on one conductor from causing "crosstalk" on another. Shielding can also affect the impedance of each conductor, further contributing to desired electrical properties.

[0010] Examples of shields can be seen in U.S. Patent No. 4,632,476 and U.S. Patent No. 4,806,107, which show connector designs that use shields between multiple columns of signal contacts. These patents describe connectors in which the shield extends parallel to the signal contacts through the daughterboard connector and the backplane connector. Cantilever beams are used to establish electrical contact between the shield and the backplane connector. U.S. Patent Nos. 5,433,617, 5,429,521, 5,429,520, and 5,433,618 show similar arrangements, however, the electrical connection between the backplane and the shield is made through spring-loaded contacts. The connector described in U.S. Patent No. 6,299,438 uses a shield with torsion beam contacts. Other shields are shown in U.S. Pre-Grant Publication 2013-0109232.

[0011] Other connectors have shields only within the daughter card connector. Examples of such connector designs can be found in U.S. Patents No. 4,846,727, 4,975,084, 5,496,183, and 5,066,236. Another example of a shielded connector is shown in U.S. Patent No. 5,484,310 and U.S. Patent No. 7,985,097, which have shields only within the daughter card connector.

[0012] Other techniques can be used to control the performance of the connector. For example, transmitting signals differentially can also reduce crosstalk. Differential signals are carried on a pair of conductive paths called a "differential pair." The potential difference between the conductive paths represents the signal. Typically, differential pairs are designed to have preferred coupling between the conductive paths of the differential pair. For example, the two conductive paths of a differential pair can be arranged to extend closer to each other than adjacent signal paths in the connector. It is not desirable to have a shield between the conductive paths of the differential pair, but a shield can be used between the differential pairs. Electrical connectors can be designed for differential signals as well as single-ended signals. Examples of differential electrical connectors are shown in U.S. Patents No. 6,293,827, No. 6,503,103, No. 6,776,659, No. 7,163,421, and No. 7,794,278.

[0013] In an interconnect system, such a connector is attached to a printed circuit board. Typically, a printed circuit board is formed as a multilayer assembly made of a stack of dielectric sheets, sometimes referred to as "prepregs." Some or all of the dielectric sheets may have a conductive film on one or both surfaces. Some of the conductive films may be patterned using photolithography or laser printing techniques to form conductive traces for interconnecting circuit boards, circuits, and / or circuit elements. Other conductive films may remain substantially intact and may be used as ground planes or power planes to provide a reference potential. The dielectric sheets may be formed into an integral board structure, for example, by pressing the stacked dielectric sheets together under pressure.

[0014] To make electrical connections to conductive traces or ground / power planes, holes may be drilled in a printed circuit board. These holes, or "vias," are filled or plated with metal so that the via is electrically connected to one or more of the conductive traces or planes it passes through.

[0015] To attach the connector to a printed circuit board, the contact "tails" of the connector may be inserted into vias or attached to conductive pads on the surface of the printed circuit board that connect to the vias. Summary of the Invention

[0016] Embodiments of a high-speed, high-density interconnect system are described. According to some embodiments, ultra-high-speed performance can be achieved through a flexible shield that provides shielding around contact tails extending from a connector housing. Alternatively or additionally, the flexible shield can provide current flow in a desired location between a shield member within the connector and a ground structure within a printed circuit board.

[0017] Therefore, some embodiments relate to a flexible shield for an electrical connector including a plurality of contact tails for attachment to a printed circuit board. The flexible shield may include a conductive body portion having a plurality of openings sized and positioned to allow the contact tails of the electrical connector to pass therethrough. The conductive body provides a current flow path between the shield within the electrical connector and a ground structure of the printed circuit board.

[0018] In some embodiments, an electrical connector can have a board-mounting surface including a plurality of contact tails extending therefrom, a plurality of internal shields, and a flexible shield. The flexible shield can include a conductive body portion including a plurality of openings sized and positioned to pass through the plurality of contact tails. The conductive body portion can be electrically connected to the plurality of internal shields.

[0019] In some embodiments, an electronic device may be provided. The electronic device may include a printed circuit board (PCB) including a surface and a connector mounted to the PCB. The connector may include a face parallel to the surface, a plurality of conductive elements extending through the face, a plurality of internal shields, and a flexible shield providing a current flow path between the plurality of internal shields and a ground structure of the PCB.

[0020] The foregoing is a non-limiting summary of the invention, which is defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component illustrated in different figures is represented by a like reference numeral. For clarity, not every component may be labeled in every figure. In the drawings:

[0022] Figure 1 is an isometric view of an exemplary electrical interconnect system according to some embodiments;

[0023] Figure 2 yes Figure 1 a partially cutaway isometric view of a backplane connector;

[0024] Figure 3 yes Figure 2 An isometric view of the pin assembly of the backplane connector;

[0025] Figure 4 yes Figure 3 Exploded view of the pin assembly;

[0026] Figure 5 yes Figure 3 An isometric view of a signal conductor of a pin assembly;

[0027] Figure 6 yes Figure 1 a partially exploded isometric view of a daughter card connector;

[0028] Figure 7 yes Figure 6 an isometric view of a wafer assembly of a daughter card connector;

[0029] Figure 8 yes Figure 7 an isometric view of a sheet module of a sheet assembly;

[0030] Figure 9 yes Figure 7 an isometric view of a portion of an insulating housing of a wafer assembly;

[0031] Figure 10 yes Figure 7 a partially exploded isometric view of a wafer module of a wafer assembly;

[0032] Figure 11 yes Figure 7 a partially exploded isometric view of a portion of a wafer module of a wafer assembly;

[0033] Figure 12 yes Figure 7 a partially exploded isometric view of a portion of a wafer module of a wafer assembly;

[0034] Figure 13 yes Figure 7 an isometric view of a pair of conductive elements of a wafer module of a wafer assembly;

[0035] Figure 14A yes Figure 13 a side view of a pair of conductive elements;

[0036] Figure 14B It is along Figure 14A The line BB intercepts Figure 13 an end view of a pair of conductive elements;

[0037] Figure 15 is an isometric view of two wafer modules and a partially exploded view of a flexible shield of a connector according to some embodiments;

[0038] Figure 16 is shown attached to two thin-sheet modules Figure 15 an insulating portion of a flexible shield and showing an isometric view of a flexible conductive member;

[0039] Figure 17A is shown installed with Figure 16 an isometric view of the flexible conductive member adjacent to the insulating portion of the flexible shield;

[0040] Figure 17B is a plan view of a surface of the flexible shield facing the circuit board;

[0041] Figure 18 depicts a connector footprint in a printed circuit board with wide routing channels according to some embodiments;

[0042] Figure 19 depicts a connector footprint in a printed circuit board having a surface ground pad according to some embodiments;

[0043] Figure 20 depicts a connector footprint in a printed circuit board having a surface ground pad and shadowed vias according to some embodiments;

[0044] Figure 21ADepicts a connector footprint in a printed circuit board with a surface ground pattern according to some embodiments. Dashed lines illustrate the location of the flexible conductive member;

[0045] Figure 21B corresponds to Figure 21A Cross-sectional view of the cutting line in ;

[0046] Figure 22A is a partial plan view of a circuit board-facing surface of a flexible shield mounted to a connector according to some embodiments;

[0047] Figure 22B corresponds to Figure 22A A cross-sectional view of the cutting line BB in FIG;

[0048] Figure 23 corresponds to Figure 17A a cross-sectional view taken along plane 23;

[0049] Figure 24 is an isometric view of two sheet modules according to some embodiments;

[0050] Figure 25A is an isometric view of a flexible shield according to some embodiments;

[0051] Figure 25B yes Figure 25A An enlarged plan view of the area marked as 25B in FIG.

[0052] Figure 26A is according to some embodiments corresponding to Figure 25B A cross-sectional view taken along the cut line 26 in FIG. 1 , showing the flexible shield in an uncompressed state;

[0053] Figure 26B yes Figure 26A A cross-sectional view of a portion of the flexible shield in a compressed state; and

[0054] Figure 27 Depicted is a connector footprint in a printed circuit board with surface ground pads and shadowed vias, according to some embodiments. DETAILED DESCRIPTION

[0055] The inventors have recognized and appreciated that the performance of high-density interconnect systems, particularly those carrying ultra-high frequency signals that must support high data rates, can be increased through connector designs that provide shielding in the area between the electrical connector and the substrate to which the connector is mounted. The shielding can separate the contact tails of conductive elements within the connector. The contact tails can extend from the connector and be electrically connected to a substrate (e.g., a printed circuit board).

[0056] Furthermore, the flexible shield, in combination with the connector and the printed circuit board to which the connector is mounted, can be configured to provide current flow paths between the shield within the connector and ground structures in the printed circuit board. These paths can extend parallel to the current paths in the signal conductors that pass from the connector to the printed circuit board. The inventors have discovered that this configuration, while only over very small distances, such as 2 mm or less, provides a desirable increase in signal integrity, particularly for high-frequency signals.

[0057] This current path can be provided by a conductive element extending from the connector, which can be a protrusion. The protrusion can be electrically connected to the surface pads on the printed circuit board through a flexible shield. The surface pads can, in turn, be connected to the internal ground layer of the printed circuit board through vias that receive the contact tails of the connector plus shadow vias. The shadow vias can be positioned adjacent to the ends of the protrusions extending from the connector. These protrusions can be adjacent to the contact tails of the signal conductors that also extend from the connector. Thus, there can be a current flow path that is appropriately positioned: through the shield inside the connector, into the protrusion, through the flexible shield, into the pads on the surface of the printed circuit board, and through the shadow vias to the internal ground layer of the printed circuit board.

[0058] The electrical connection through the shield can be facilitated by the flexibility of the shield so that the shield can be compressed when the connector is mounted to the printed circuit board. The flexibility can enable the shield to occupy the space between the connector and the printed circuit board despite variations in separation that may occur due to manufacturing tolerances.

[0059] Additionally, the shield can be made of a material that provides a force in an orthogonal direction when compressed, such as by responding to a force on the shield in a first direction by expanding and exerting a force on any adjacent structure in a second direction, which can be orthogonal to the first direction. Suitable flexible conductive materials for making at least a portion of the shield include elastomers filled with conductive particles.

[0060] Applying force in at least two orthogonal directions when the shield is compressed can cause the shield to press against the conductive pads on the surface of the printed circuit board and the conductive elements extending from the connector. Those extended structures can have surfaces that are orthogonal to the surface of the printed circuit board. By contacting the extended conductive elements on the surface, a wide area over which contact is made is provided, thereby improving the performance of the connector relative to contacting the shield along the edge of the extended conductive elements.

[0061] To provide mechanical support for the flexible conductive material and other structures, the flexible shield can include an insulating member. The insulating member can have a first portion that can be generally planar and shaped on one surface to support a mounting surface of the connector. An opposing surface of the insulating member can have a plurality of raised portions forming islands extending from the first portion. The islands can have walls, and the flexible conductive material can occupy the spaces between the walls. Extended conductive elements can be positioned adjacent to the walls such that when the flexible conductive material is compressed, it expands outwardly toward the walls, pressing against the extended conductive elements. The extended conductive elements can be supported by the walls and mechanically supported thereby.

[0062] The island can provide an insulating area of ​​the shield through which the signal conductor can be grounded without contacting the flexible conductive material. In some embodiments, the island can be formed from a material having a dielectric constant that establishes the required impedance for the signal conductor in the mounting interface of the connector. In some embodiments, the relative dielectric constant can be 3.0 or higher. In some embodiments, the relative dielectric constant can be higher, such as 3.4 or higher. In some embodiments, the relative dielectric constant of at least the island can be 3.5 or higher, 3.6 or higher, 3.7 or higher, 3.8 or higher, 3.9 or higher, or 4.0 or higher. Such relative dielectric constants can be achieved by selecting adhesive materials and fillers. Known materials can be selected to provide, for example, a relative dielectric constant of up to 4.5. In some embodiments, the relative dielectric constant can be as high as 4.4, as high as 4.3, as high as 4.2, as high as 4.1, or as high as 4.0. Relative dielectric constants within these ranges can result in the dielectric constant of the island being higher than the dielectric constant of the insulating housing of the connector. The island may, in some embodiments, have a relative dielectric constant that is at least 0.1, 0.2, 0.3, 0.4, 0.5, or 0.6 higher than the connector housing. In some embodiments, the difference in relative dielectric constant will be in the range of 0.1 to 0.3, or 0.2 to 0.5, or 0.3 to 1.0.

[0063] In other embodiments, a current path between the shield within the connector and a ground structure in the printed circuit board can be created by contact tails extending from an internal connector shield that engages a conductive pad on the printed circuit board. The flexible shield can include a conductive body and a plurality of flexible fingers attached to and extending from the conductive body. Such a flexible shield can be formed from a sheet of conductive material.

[0064] According to some embodiments, a flexible shield may include a conductive body and a plurality of flexible members. The flexible members may be attached to and extend from the conductive body. The flexible members may be in the form of flexible fingers or any other suitable shape. The conductive body may be electrically connected to surface pads on a printed circuit board. The surface pads may, in turn, be connected to an internal ground layer of the printed circuit board via vias that receive contact tails of a connector plus shadow vias.

[0065] The flexible shield can be made of a material having the desired conductivity for the current path. The material can also be suitably elastic so that the fingers cut from the material generate sufficient force to make a reliable electrical connection to the surface pads of the printed circuit board and / or the conductive structures extending from the connector. Suitable flexible conductive materials for making at least a portion of the flexible shield include metals, metal alloys, superelastics, and shape memory materials. Superelastic and shape memory materials are described in co-pending U.S. Pre-Grant Publication No. 2016-0308296, the entire contents of which are incorporated herein by reference.

[0066] Electrical connection through a flexible shield can be facilitated by the shield's flexibility, allowing it to compress when the connector is mounted to a printed circuit board. The flexibility enables the shield to generate force against the printed circuit board, regardless of spacing variations that may occur due to manufacturing tolerances. In embodiments where flexibility is generated by deflection of fingers cut from a sheet of metal, the fingers, in an uncompressed state, can flex out of the plane of the sheet of metal by an amount equal to the tolerance in positioning the connector's mounting face against the upper surface of the printed circuit board.

[0067] The shield's flexibility can be provided by resilient fingers that deform to accommodate manufacturing variations in the separation between the circuit board and the connector. The fingers can extend from a metal sheet positioned between the connector and the printed circuit board. However, in some embodiments, the fingers can extend from an internal shield or ground structure of the connector, passing through and electrically contacting a metal component between the mounting surface of the connector housing and the upper surface of the printed circuit board.

[0068] In some embodiments, the shadow via can be positioned near the distal end of a finger extending from the flexible shield. The finger can be adjacent to the contact tail of a signal conductor extending from the connector. In some embodiments, the proximal end of the finger can be attached to the body of the shield. The shield can be configured to engage a ground contact tail, protrusion, or other conductive structure extending from the shield within the connector. Thus, a suitably positioned current flow path can exist that passes through the shield within the connector, through the flexible shield, into a pad on the surface of the printed circuit board, and through the shadow via to an internal ground layer of the printed circuit board.

[0069] Figure 1 The figures show an electrical interconnect system in a form that can be used in an electronic system. In this example, the electrical interconnect system includes a right-angle connector and can be used, for example, to electrically connect a daughter card to a backplane. The figures show two mating connectors. In this example, connector 200 is designed to be attached to a backplane and connector 600 is designed to be attached to a daughter card. Figure 1 As can be seen in the diagram, the daughter card connector 600 includes contact tails 610 designed to be attached to a daughter card (not shown). The backplane connector 200 includes contact tails 210 designed to be attached to a backplane (not shown). These contact tails form one end of a conductive element that passes through the interconnect system. When the connector is mounted to a printed circuit board, these contact tails will be electrically connected to signal-carrying conductive structures within the printed circuit board or to a reference potential. In the example shown, the contact tails are press-fit "eye-of-the-needle" type contacts, which are designed to be pressed into vias in the printed circuit board. However, other forms of contact tails may be used.

[0070] Each connector in the connector also has a mating interface where the connector can mate or unmate with another connector. The daughter card connector 600 includes a mating interface 620. The backplane connector 200 includes a mating interface 220. Although Figure 1 It is not fully visible in the view shown in , but the mating contact portions of the conductive elements are exposed at the mating interface.

[0071] Each of these conductive elements includes an intermediate portion that connects the contact tail to the mating contact portion. The intermediate portion can be retained within a connector housing, and at least a portion of the connector housing can be dielectric to provide electrical isolation between the conductive elements. In addition, the connector housing can include conductive or lossy portions, which in some embodiments can provide conductive or partially conductive paths between some of the conductive elements. In some embodiments, the conductive portion can provide shielding. The lossy portion can also provide shielding in some cases and / or can provide desired electrical performance within the connector.

[0072] In various embodiments, the dielectric member can be molded or overmolded from a dielectric material such as plastic or nylon. Examples of suitable materials include, but are not limited to, liquid crystal polymer (LCP), polyphenylene sulfide (PPS), high-temperature nylon or polyphenylene oxide (PPO), or polypropylene (PP). Other suitable materials may be used, as aspects of the present disclosure are not limited in this regard.

[0073] All of the aforementioned materials are suitable for use as binder materials in connector manufacturing. According to some embodiments, one or more fillers may be included in some or all of the binder materials. As a non-limiting example, a thermoplastic PPS filled with 30% glass fiber by volume may be used to form the entire connector housing or the dielectric portion of the housing.

[0074] Alternatively or additionally, a portion of the housing can be formed from a conductive material such as processed metal or extruded metal powder. In some embodiments, a portion of the housing can be formed from metal or other conductive material and a dielectric member that separates the signal conductors from the conductive portion. In the illustrated embodiment, for example, the housing of backplane connector 200 can have a region formed from a conductive material and an insulating member that separates the intermediate portion of the signal conductors from the conductive portion of the housing.

[0075] The housing of the daughter card connector 600 may also be formed in any suitable manner. In the illustrated embodiment, the daughter card connector 600 may be formed from a plurality of subassemblies referred to herein as "sheets." Each sheet (700, Figure 7 ) can include a housing portion that can similarly include dielectric / lossy and / or conductive portions. One or more members can hold the sheets in a desired position. For example, support members 612 and 614 can respectively hold the top and back of multiple sheets in a side-by-side configuration. Support members 612 and 614 can be formed of any suitable material, such as sheet metal stamped with protrusions, openings, or other features that engage corresponding features on a single sheet.

[0076] Other components that may form part of the connector housing may provide mechanical integrity to the daughter card connector 600 and / or hold the tabs in a desired position. For example, the front housing portion 640 ( Figure 6 ) can receive the portion of the sheet that forms the mating interface. Any or all of these portions of the connector housing can be dielectric, lossy and / or conductive to achieve the desired electrical performance of the interconnect system.

[0077] In some embodiments, each sheet may hold a column of conductive elements forming signal conductors. These signal conductors may be shaped and spaced to form single-ended signal conductors. However, in Figure 1 In the embodiment shown in FIG, the signal conductors are shaped in pairs that are spaced apart to provide differential signal conductors. Each of the columns may include or be bounded by a conductive element that functions as a ground conductor. It should be understood that the ground conductors need not be connected to ground, but are shaped to carry a reference potential, which may include ground voltage, a DC voltage, or other suitable reference potential. The "ground" or "reference" conductors may have a different shape than the signal conductors, which are configured to provide suitable signal transmission performance for high-frequency signals.

[0078] The conductive elements can be made of metal or any other material that is electrically conductive and provides suitable mechanical properties for conductive elements in electrical connectors. Phosphor bronze, beryllium copper, and other copper alloys are non-limiting examples of materials that can be used. The conductive elements can be formed from such materials in any suitable manner, including by stamping and / or forming.

[0079] The spacing between conductors of adjacent columns can be within a range that provides the desired density and desired signal integrity. As a non-limiting example, the conductors can be stamped from a 0.4 mm thick copper alloy, and the conductors within each column can be spaced 2.25 mm apart and the conductors within each column can be spaced 2.4 mm apart. However, higher density can be achieved by placing the conductors closer together. In other embodiments, for example, smaller sizes can be used to provide higher density, such as a thickness between 0.2 mm and 0.4 mm, or a spacing between conductors between columns or within a column of 0.7 mm to 1.85 mm. In addition, each column can include four pairs of signal conductors, so that Figure 1 The interconnect system shown in achieves a density of 60 or more pairs per linear inch. However, it should be understood that higher density connectors can be achieved using more pairs per column, tighter spacing between pairs within a column, and / or smaller distances between columns.

[0080] The sheet can be formed in any suitable manner. In some embodiments, the sheet can be formed by stamping multiple columns of conductor elements from a metal sheet and overmolding a dielectric portion over the intermediate portions of the conductor elements. In other embodiments, the sheet can be assembled from modules, each module including a single single-ended signal conductor, a single pair of differential signal conductors, or any suitable number of single-ended or differential pairs.

[0081] Assembling the sheets from modules can help reduce the "skew" of signal pairs at higher frequencies, such as between about 25 GHz and 40 GHz, or higher. In this context, skew refers to the difference in electrical propagation time between a pair of signals operating as differential signals. A module structure designed to reduce skew is described, for example, in co-pending application 61 / 930,411, which is incorporated herein by reference.

[0082] According to the technology described in the co-pending application, in some embodiments, the connector can be formed from modules, each module carrying a signal pair. The modules can be individually shielded, such as by attaching a shielding member to the module and / or inserting the module into an organizer or other structure that can provide electrical shielding between multiple pairs and / or around the signal-carrying conductive elements.

[0083] In some embodiments, the signal conductor pairs within each module can be broadside coupled for a major portion of their length. Broadside coupling allows a pair of signal conductors to have the same physical length. To facilitate routing of signal traces within the connector footprint of a printed circuit board to which the connector is attached and / or construction of the mating interface of the connector, the signal conductors can be aligned in an edge-to-edge coupled manner in one or both of these regions. Thus, the signal conductors can include transition regions where the coupling changes from edge-to-edge to broadside or vice versa. As described below, these transition regions can be designed to prevent mode conversion or suppress undesirable propagation modes that may interfere with the signal integrity of the interconnect system.

[0084] Modules can be assembled into sheets or other connector structures. In some embodiments, different modules can be formed for each row position of a pair of right-angle connectors. These modules can be manufactured to be used together to build connectors with as many rows as desired. For example, a module of one shape can be formed for a pair of conductive elements to be positioned at the shortest row of the connector (sometimes referred to as the ab row). A separate module can be formed for the conductive elements in the second longest row (sometimes referred to as the cd row). The interior of the module in the cd row can be designed to conform to the exterior of the module in the ab row.

[0085] This pattern can be repeated for any number of pairs. Each module can be shaped to be used with modules that carry multiple pairs of conductor elements in shorter and / or longer rows. To manufacture any suitable size connector, connector manufacturers can assemble multiple modules into a thin sheet to provide the desired number of pairs in the thin sheet. In this way, connector manufacturers can promote widely used connector sizes such as 2 pairs to connector series. When customer demand changes, connector manufacturers can obtain tools for each additional pair or obtain tools for modules that contain multiple pairs or multiple pairs of groups to produce larger-sized connectors. Tools for producing modules for smaller connectors can be used to produce modules for shorter rows or even shorter rows of larger connectors. Figure 8 Such a modular connector is shown in .

[0086] Figure 2 Provided in Figure 1 Additional details of the construction of the interconnect system are shown with the backplane connector 200 partially cut away. Figure 2 In the embodiment shown in FIG, the front wall of the housing 222 is cut away to reveal the interior of the mating interface 220 .

[0087] In the illustrated embodiment, the backplane connector 200 also has a modular construction. A plurality of pin modules 300 are organized to form an array of conductive elements. Each pin module in the pin modules 300 can be designed to mate with a module of the daughter card connector 600.

[0088] In the illustrated embodiment, four rows by eight columns of pin modules 300 are shown. With each pin module having two signal conductors, the four rows 230A, 230B, 230C, and 230D of pin modules produce a total of four pairs or eight columns of signal conductors. However, it should be understood that the number of signal conductors per row or column is not a limitation of the present invention. A greater or lesser number of rows of pin modules may be included within the housing 222. Similarly, a greater or lesser number of columns may be included within the housing 222. Alternatively or additionally, the housing 222 may be viewed as a module of a backplane connector, and multiple such modules may be aligned edge to edge to extend the length of the backplane connector.

[0089] exist Figure 2 In the embodiment shown in FIG, each of the pin modules 300 includes conductive elements that serve as signal conductors. These signal conductors are held within an insulating member that may serve as part of the housing of the backplane connector 200. The insulating portion of the pin module 300 may be positioned to separate the signal conductors from the rest of the housing 222. In this configuration, the rest of the housing 222 may be conductive or partially conductive, such as may result from the use of lossy materials.

[0090] In some embodiments, the housing 222 can include both conductive and lossy portions. For example, the shield, including the walls 226 and the base plate 228, can be extruded from powdered metal or formed from a conductive material in any other suitable manner. The pin module 300 can be inserted into an opening in the base plate 228.

[0091] Lossy or conductive members may be positioned adjacent to adjacent rows 230A, 230B, 230C, and 230D of the pin module 300. Figure 2 224C are shown between adjacent rows of pin modules. The dividers 224A, 224B, and 224C can be conductive or lossy and can be formed as identically operated parts or from the same components that form the walls 226 and the bottom plate 228. Alternatively, the dividers 224A, 224B, and 224C can be separately inserted into the housing 222 after the walls 226 and the bottom plate 228 are formed. In embodiments where the dividers 224A, 224B, and 224C are separately formed from the walls 226 and the bottom plate 228 and subsequently inserted into the housing 222, the dividers 224A, 224B, and 224C can be formed from a different material than the walls 226 and / or the bottom plate 228. For example, in some embodiments, the walls 226 and the bottom plate 228 can be conductive and the dividers 224A, 224B, and 224C can be lossy or partially lossy and partially conductive.

[0092] In some embodiments, other lossy or conductive members may extend perpendicular to the backplane 228 to the mating interface 220. Member 240 is shown adjacent to the endmost rows 230A and 230D. In contrast to the spacers 224A, 224B, and 224C extending across the mating interface 220, spacer members 240, having a width approximately equal to the width of a column, are positioned in a row adjacent to rows 230A and 230D. The daughter card connector 600 may include slots in its mating interface 620 for receiving the spacers 224A, 224B, and 224C. The daughter card connector 600 may include openings similarly adapted to receive the members 240. Member 240 may have similar electrical effects as the spacers 224A, 224B, and 224C, all of which may suppress resonance, crosstalk, or other undesirable electrical effects. Because member 240 fits into an opening in daughter card connector 600 that is smaller than dividers 224A, 224B, and 224C, member 240 can achieve greater mechanical integrity of the housing portion of daughter card connector 600 on the side that receives member 240 .

[0093] Figure 3 The pin modules 300 are shown in greater detail. In this embodiment, each pin module includes a pair of conductive elements serving as signal conductors 314A and 314B. Each of the signal conductors has a mating interface portion shaped as a pin. Opposite ends of the signal conductors have contact tails 316A and 316B. In this embodiment, the contact tails are shaped as press-fit flexible sections. The middle portion of the signal conductors, connecting the contact tails to the mating contact portion, passes through the pin module 300.

[0094] Conductive elements serving as reference conductors 320A and 320B are attached to opposing outer surfaces of the pin module 300. Each of the reference conductors has a contact tail 328 shaped for electrical connection to a via in a printed circuit board. The reference conductors also have a mating contact portion. In the illustrated embodiment, two types of mating contacts are shown. The flexible member 322 can serve as a mating contact portion that presses against the reference conductors in the daughter card connector 600. In some embodiments, surfaces 324 and 326 can alternatively or additionally serve as mating contacts, wherein a reference conductor of the mating conductor can press against the reference conductor 320A or 320B. However, in the illustrated embodiment, the reference conductors can be shaped so that electrical contact is made only at the flexible member 322.

[0095] Figure 4 An exploded view of the pin module 300 is shown. The intermediate portions of the signal conductors 314A and 314B are held within an insulating member 410, which may form a portion of the housing of the backplane connector 200. The insulating member 410 may be insert molded around the signal conductors 314A and 314B. Figure 4In the exploded view of FIG, the surface 412 against which the reference conductor 320B is pressed is visible. Figure 4 Surface 428 of reference conductor 320A is seen, which is pressed against the member 410. Figure 4 Invisible surfaces.

[0096] As can be seen, surface 428 is substantially complete. Attachment features such as protrusions 432 may be formed in surface 428. Such protrusions may engage openings ( Figure 4 4 (not visible in the view shown in FIG) to retain reference conductor 320A to insulating member 410. Similar protrusions (not numbered) can be formed in reference conductor 320B. As shown, these protrusions, which serve as an attachment mechanism, are centered between signal conductors 314A and 314B where radiation from or affecting this pair of conductive elements is relatively low. Additionally, protrusions such as 436 can be formed in reference conductors 320A and 320B. Protrusions 436 can engage insulating member 410 to retain pin module 300 in the opening in base plate 228.

[0097] In the illustrated embodiment, flexible member 322 is not cut from the planar portion of reference conductor 320B that presses against surface 412 of insulating member 410. Instead, flexible member 322 is formed from a different portion of sheet metal and folded parallel to the planar portion of reference conductor 320B. In this manner, no opening is left in the planar portion of reference conductor 320B for forming flexible member 322. Furthermore, as shown, flexible member 322 has two flexible portions 424A and 424B that join together at their distal ends but are separated by an opening 426. This configuration can provide the mating contacts with the appropriate mating force in the desired position without leaving an opening in the shield surrounding pin module 300. However, in some embodiments, a similar effect can be achieved by attaching separate flexible members to reference conductors 320A and 320B.

[0098] Reference conductors 320A and 320B can be secured to pin module 300 in any suitable manner. As noted above, protrusions 432 can engage openings 434 in the housing portion. Additionally or alternatively, straps or other components can be used to secure other portions of the reference conductors. As shown, each reference conductor includes straps 430A and 430B. Strap 430A includes protrusions, while strap 430B includes openings adapted to receive these protrusions. Here, reference conductors 320A and 320B have the same shape and can be manufactured using the same tooling, but are mounted on opposing surfaces of pin module 300. Thus, protrusions 430A of one reference conductor align with protrusions 430B of the opposing reference conductor, interlocking and securing the reference conductors in place. These protrusions can engage openings 448 in the insulating member, further assisting in securing the reference conductors in a desired orientation relative to signal conductors 314A and 314B in pin module 300.

[0099] Figure 4 Further shown is a tapered surface 450 of the insulating member 410. In this embodiment, the surface 450 tapers relative to the axis of the signal conductor pair formed by the signal conductors 314A and 314B. The surface 450 is tapered in the sense that it is closer to the distal end of the mating contact portion near the axis of the signal conductor pair and further away from the axis and further away from the distal end. In the illustrated embodiment, the pin module 300 is symmetrical relative to the axis of the signal conductor pair, and the tapered surface 450 is formed adjacent to each of the signal conductors 314A and 314B.

[0100] According to some embodiments, some or all of the adjacent surfaces in the mating connector may be tapered. Figure 4 Not shown, the surface of the insulating portion of daughter card connector 600 adjacent to tapered surface 450 may be tapered in a complementary manner so that the surface of the mating connector conforms to the surface of the connector when the connectors are in the designed mated position.

[0101] Tapered surfaces in the mating interface can avoid abrupt changes in impedance depending on the connector separation. Therefore, other surfaces designed to be adjacent to the mating connector can be similarly tapered. Figure 4 Such a tapered surface 452 is shown. As shown, the tapered surface 452 is between the signal conductors 314A and 314B. The surfaces 450 and 452 cooperate to provide a taper on the insulation on both sides of the signal conductors.

[0102] Figure 5 There is shown further detail of the pin module 300. Here, the signal conductors are shown separated from the pin module. Figure 5The signal conductors are shown before being overmolded with insulation or otherwise incorporated into the pin module 300. However, in some embodiments, the signal conductors may be overmolded with insulation or other means before being assembled into the module. Figure 5 The components are held together by other suitable support mechanisms not shown.

[0103] In the illustrated embodiment, signal conductors 314A and 314B are symmetrical about the axis 500 of the signal conductor pair. Each signal conductor pair has a mating contact portion shaped as a pin. Each signal conductor also has an intermediate portion 512A or 512B and 514A and 514B. Here, different widths are provided to provide impedance matching with the mating connector and printed circuit board, despite the different materials or construction techniques in each signal conductor. A transition region as shown in the figure can be included to provide a gradual transition between regions of different widths. Contact tails 516A or 516B can also be included.

[0104] In the illustrated embodiment, the middle portions 512A, 512B, 514A, and 514B can be flat with broadsides and narrower edges. In the illustrated embodiment, the pair of signal conductors are aligned edge-to-edge and are thus configured for edge coupling. In other embodiments, some or all of the signal conductor pairs can alternatively be broadside coupled.

[0105] The mating contact portion can be of any suitable shape, but in the illustrated embodiment it is cylindrical. The cylindrical portion can be formed by rolling a portion of a metal sheet into a tube or in any other suitable manner. Such a shape can be formed, for example, by stamping a shape out of a metal sheet including a middle portion. A portion of the material can be rolled into a tube to provide the mating contact portion. Alternatively or additionally, a wire or other cylindrical element can be flattened to form the middle portion, leaving a cylindrical mating contact portion. One or more openings (not numbered) can be formed in the signal conductor. Such openings can ensure that the signal conductor is securely engaged with the insulating member 410.

[0106] Go to Figure 6 , which shows further details of daughter card connector 600 in a partially exploded view. As shown, connector 600 includes a plurality of thin plates 700A held together in a side-by-side configuration. Here, eight thin plates are shown, corresponding to the eight columns of pin modules in backplane connector 200. However, as with backplane connector 200, the size of the connector assembly can be configured by incorporating more rows per thin plate, more thin plates per connector, or more connectors per interconnect system.

[0107] The conductive elements within sheet 700A can include mating contacts and contact tails. Contact tails 610 are shown extending from a surface of connector 600 adapted for mounting against a printed circuit board. In some embodiments, contact tails 610 can pass through member 630. Member 630 can include insulating, lossy, or conductive portions. In some embodiments, contact tails associated with signal conductors can pass through the insulating portion of member 630. Contact tails associated with reference conductors can pass through the lossy or conductive portion of member 630.

[0108] The mating contact portions of the sheet 700A are retained in the front housing portion 640. The front housing portion can be made of any suitable material, which can be insulating, lossy, or conductive, or can include any suitable combination of such materials. For example, the front housing portion can be molded from a filled lossy material using similar materials and techniques as described above for the housing wall 226, or can be formed from a conductive material. As shown, the sheet is composed of modules 810A, 810B, 810C, and 810D ( Figure 8 ) are assembled, each module having a pair of signal conductors surrounded by a reference conductor. In the illustrated embodiment, the front housing portion 640 has a plurality of passages, each passage being positioned to receive a pair of signal conductors and an associated reference conductor. However, it should be understood that each module may contain a single signal conductor or more than two signal conductors.

[0109] Figure 7 A thin sheet 700 is shown. A plurality of such thin sheets 700 can be aligned side by side and held together by one or more support members or in any other suitable manner to form a daughter card connector. In the illustrated embodiment, the thin sheet 700 is formed by a plurality of modules 810A, 810B, 810C, and 810D. The modules are aligned to form a row of mating contacts along one edge of the thin sheet 700 and a row of contacts along the other edge of the thin sheet 700. In embodiments where the thin sheet is designed for use in a right-angle connector, these edges are perpendicular, as shown.

[0110] In the illustrated embodiment, each module includes a reference module that at least partially encloses a signal conductor. The reference conductor may similarly have a mating contact portion and a contact tail.

[0111] The modules can be held together in any suitable manner. For example, the modules can be held within a housing, which in the illustrated embodiment is formed by components 900A and 900B. Components 900A and 900B can be formed separately and then fastened together, retaining modules 810A…810D therein. Components 900A and 900B can be held together in any suitable manner, such as by attachment components that form an interference fit or a snap fit. Alternatively or additionally, adhesives, welding, or other attachment techniques can be used.

[0112] Components 900A and 900B can be formed from any suitable material. The material can be an insulating material. Alternatively or additionally, the material can be a lossy or conductive portion or can include a lossy or conductive portion. Components 900A and 900B can be formed, for example, by molding the material into a desired shape. Alternatively, components 900A and 900B can be formed in place around modules 810A...810D, such as by insert molding. In such an embodiment, components 900A and 900B do not need to be formed separately. Instead, the housing portion that holds modules 810A...810D can be formed in one operation.

[0113] Figure 8 Modules 810A...810D are shown without components 900A and 900B. In this view, the reference conductors are visible. Signal conductors ( Figure 8 The signal conductors (not visible in the figure) are enclosed within the reference conductor to form a waveguide structure. Each waveguide structure includes a contact tail region 820, a middle region 830, and a mating contact region 840. Within the mating contact region 840 and the contact tail region 820, the signal conductors are positioned edge-to-edge. Within the middle region 830, the signal conductors are positioned for broadside coupling. Transition regions 822 and 842 are configured to transition between edge-coupled and broadside-coupled orientations.

[0114] The transition regions 822 and 842 in the reference conductor can correspond to the transition regions in the signal conductor, as described below. In the illustrated embodiment, the reference conductor forms an enclosure around the signal conductor. In some embodiments, the transition regions in the reference conductor can maintain a substantially uniform spacing between the signal conductor and the reference conductor along the length of the signal conductor. Thus, the enclosure formed by the reference conductor can have different widths in different regions.

[0115] The reference conductor provides shielding coverage along the length of the signal conductor. As shown, due to the coverage in the mating contact portion and the middle portion of the signal conductor, coverage is provided for substantially all of the length of the signal conductor. The contact tails are shown exposed so that they can contact the printed circuit board. However, in use, these mating contact portions will be adjacent to ground structures within the printed circuit board, thereby Figure 8, does not compromise shield coverage along substantially the entire length of the signal conductor. In some embodiments, the mating contact portion may also be exposed for mating to another connector. Thus, in some embodiments, shield coverage may be provided in greater than 80%, 85%, 90%, or 95% of the middle portion of the signal conductor. Similarly, shield coverage may also be provided in the transition region such that shield coverage may be provided in greater than 80%, 85%, 90%, or 95% of the combined length of the middle portion and the transition region of the signal conductor. In some embodiments, the mating contact region and some or all of the mating contacts may also be shielded such that shield coverage may be provided in various embodiments for greater than 80%, 85%, 90%, or 95% of the length of the signal conductor.

[0116] In the illustrated embodiment, the waveguide-like structure formed by the reference conductor has a wide dimension in the column direction of the connector in the contact tail region 820 and the mating contact region 840 to accommodate the wide dimension of the signal conductors arranged side by side in the column direction in these regions. In the illustrated embodiment, the contact tail region 820 and the mating contact region 840 of the signal conductor are separated by a distance to align with the mating contacts of the mating connector or contact structure on the printed circuit board to which the connector is to be attached.

[0117] These spacing requirements mean that the waveguides are wider in the column dimension than in the lateral direction, thereby providing that the waveguides in these regions may have an aspect ratio of at least 2: 1 and in some embodiments may be on the order of at least 3: 1. In contrast, in the intermediate portion 830, the signal conductors are oriented with the wide dimension of the signal conductors overlying the column direction, resulting in a waveguide aspect ratio that may be less than 2: 1 and in some embodiments may be less than 1.5: 1 or on the order of 1: 1.

[0118] By virtue of this smaller aspect ratio, the maximum dimension of the waveguide in the middle portion 830 will be smaller than the minimum dimension of the waveguide in regions 830 and 840. Because the lowest frequency of waveguide propagation is inversely proportional to the length of its shortest dimension, the lowest frequency mode of propagation that can be excited in the middle portion 830 is higher than the frequency modes that can be excited in the contact tail region 820 and the mating contact region 840. The lowest frequency mode that can be excited in the transition region will be intermediate to the frequency modes excited in the contact tail region 820 and the mating contact region 840. Because the transition from edge coupling to broadside coupling has the potential to excite desirable waveguide modes, signal integrity can be improved in situations where these modes are at frequencies higher than, or at least as high as possible, the expected operating range of the connector.

[0119] These regions can be configured to avoid mode conversion at the transition between the coupling regions, which could excite undesirable signals propagating through the waveguide. For example, as shown below, the signal conductor can be shaped so that the transition occurs in the intermediate region 830 or in the transition regions 822 and 842, or partially in both. Additionally or alternatively, the module can be configured to suppress the excitation of undesirable modes in the waveguide formed by the reference conductor, as described in more detail below.

[0120] While the reference conductors can substantially enclose each pair of signal conductors, the enclosure is not required to be without openings. Thus, in an embodiment shaped to provide a rectangular shield, the reference conductors in the middle portion can be aligned with at least a portion of all four sides of the signal conductors. The reference conductors can be combined to provide, for example, 360-degree coverage around a pair of signal conductors. Such coverage can be provided, for example, by overlapping or physically contacting the reference conductors. In the illustrated embodiment, the reference conductors are U-shaped shells and together form the enclosure.

[0121] Regardless of the shape of the reference conductor, three hundred and sixty degrees of coverage can be provided. For example, such coverage can be provided with a reference conductor that is circular, oval, or any other suitable shape. However, the coverage is not required to be complete. The coverage can, for example, have an angular range between approximately 270 and 365 degrees. In some embodiments, the coverage can be between approximately 340 and 360 degrees. Such coverage can be achieved, for example, by slots or other openings in the reference conductor.

[0122] In some embodiments, the shield coverage can be different in different regions. In the transition region, the shield coverage can be greater than in the intermediate region. In some embodiments, due to direct contact or even overlap in the reference conductors in the transition region, the shield coverage can have an angular range greater than 355 degrees, or even in some embodiments, 360 degrees, even though less shield coverage is provided in the transition region.

[0123] The inventors have recognized and appreciated that, in a sense, completely enclosing a signal pair in a reference conductor within a central region can have undesirable effects on signal integrity, particularly when used in conjunction with the transition between edge coupling and broadside coupling within a module. The reference module surrounding the signal pair can form a waveguide. Signals on the pair of signal conductors, and particularly within the transition region between edge coupling and broadside coupling, can cause energy in a differential propagation mode between the edges to excite signals that can propagate within the waveguide. According to some embodiments, one or more techniques can be used to avoid excitation of these undesirable modes or to suppress them if they are excited.

[0124] Some techniques that can be used to increase the frequency can excite undesirable modes. In the illustrated embodiment, the reference conductor can be shaped to leave openings 832. These openings can be in the narrow walls of the enclosure. However, in embodiments where there are wide walls, the openings can be in the wide walls. In the illustrated embodiment, the openings 832 extend parallel to the middle portions of the signal conductors and are located between the signal conductors that form a pair. These slots reduce the angular range of the shielding so that near the middle portions of the signal conductors that are coupled via the broadsides, the angular range of the shielding can be less than 360 degrees. The angular range can be, for example, in the range of 355 degrees or less. In embodiments where components 900A and 900B are formed by overmolding lossy material onto the modules, the lossy material can be allowed to fill the openings 932 with or without extending into the interior of the waveguide, which can inhibit the propagation of undesirable signal propagation modes that can reduce signal integrity.

[0125] exist Figure 8 In the embodiment shown in FIG, the opening 832 is slot-shaped, effectively dividing the shield in the middle region 830 into two parts. Figure 8 As shown in the effect of the reference conductor substantially surrounding the signal conductor, the lowest frequency that can be excited in a structure used as a waveguide is inversely proportional to the size of the side surface. In some embodiments, the lowest frequency waveguide mode that can be excited is a TEM mode. By effectively shortening the side surface by incorporating the slot-like opening 832, the frequency of the TEM mode that can be excited is increased. A higher resonant frequency can mean that less energy within the operating frequency range of the connector is coupled into undesired propagation within the waveguide formed by the reference conductor, which improves signal integrity.

[0126] In region 830, a pair of signal conductors are broadside coupled, and openings 832 with or without lossy material therein can suppress the TEM common propagation mode. While not being bound by any particular theory of operation, the inventors theorize that openings 832, incorporating the edge-coupled to broadside-coupled transition, help provide a balanced connector suitable for high-frequency operation.

[0127] Figure 9 Component 900 is shown, which may be representative of components 900A or 900B. As can be seen, component 900 is formed with channels 910A...910D shaped to receive Figure 8 Modules 810A...810D are shown in FIG. With the modules positioned in the channel, component 900A can be secured to component 900B. In the illustrated embodiment, components 900A and 900B can be attached by having a post, such as post 920, in one component pass through a hole, such as hole 930, in the other component. The post can be welded or otherwise secured in the hole. However, any suitable attachment mechanism can be used.

[0128] Components 900A and 900B can be molded from or include lossy materials. These and other lossy structures can use any suitable lossy material. Materials that are electrically conductive but have some loss, or that attract electromagnetic energy through another physical mechanism within the frequency range of interest, are generally referred to herein as "lossy" materials. Electrically lossy materials can be formed from lossy dielectric materials and / or weakly conductive materials and / or lossy magnetic materials. Magnetic lossy materials can, for example, be formed from materials traditionally considered ferromagnetic, such as those having a magnetic loss factor greater than approximately 0.05 within the frequency range of interest. The "magnetic loss factor" is the ratio of the imaginary part to the real part of a material's complex electromagnetic constant. Actual magnetic lossy materials or mixtures containing magnetic lossy materials can also exhibit useful amounts of dielectric loss or conductive loss effects within a portion of the frequency range of interest. Electrically lossy materials can be formed from materials traditionally considered dielectric materials, such as those having an electrical loss factor greater than approximately 0.05 within the frequency range of interest. The "electrical loss factor" is the ratio of the imaginary part to the real part of a material's complex dielectric constant. Electrically lossy materials may also be formed from materials that are generally considered conductors but are relatively poor conductors in the frequency range of interest, containing substantially dispersed conductive particles or regions that do not provide high electrical conductivity or are otherwise prepared with properties that result in relatively poor bulk electrical conductivity in the frequency range of interest compared to good conductors such as copper.

[0129] Electrically lossy materials typically have a bulk conductivity of about 1 Siemens / meter to about 10,000 Siemens / meter, and preferably about 1 Siemens / meter to about 5,000 Siemens / meter. In some embodiments, materials with a bulk conductivity between about 10 Siemens / meter and about 200 Siemens / meter can be used. As a specific example, a material with a conductivity of about 50 Siemens / meter can be used. However, it should be understood that the conductivity of the material can be selected empirically or through electrical simulation using known simulation tools to determine an appropriate conductivity that provides suitably low crosstalk and suitably low signal path attenuation or insertion loss.

[0130] The electrically lossy material can be a partially conductive material such as a material having a surface resistivity between 1 Ω / square and 100,000 Ω / square. In some embodiments, the electrically lossy material has a surface resistivity between 10 Ω / square and 1000 Ω / square. As a specific example, the material can have a surface resistivity between approximately 20 Ω / square and 80 Ω / square.

[0131] In some embodiments, the lossy material is formed by adding a filler containing conductive particles to an adhesive. In such embodiments, the lossy member can be formed by molding or otherwise shaping the filler-containing adhesive into the desired shape. Examples of conductive particles that can be used as fillers to form the lossy material include carbon or graphite formed into fibers, flakes, nanoparticles, or other types of particles. Metals or other particles in powder, flake, or fiber form can also be used to provide appropriate lossy properties. Alternatively, a combination of fillers can be used. For example, a metal coated with carbon particles can be used. Silver and nickel are suitable metals for fiber coating. Coated particles can be used alone or in combination with other fillers, such as carbon flakes. The adhesive or matrix can be any material that will be placed, cured, or can be used to position the filler material. In some embodiments, the adhesive can be a thermoplastic material, which is traditionally used as part of the manufacturing of electrical connectors to facilitate molding the lossy material into the desired shape and position. Examples of such materials include liquid crystal polymer (LCP) and nylon. However, many alternative adhesive materials can be used. Curable materials such as epoxy resin can be used as the adhesive. Alternatively, materials such as thermosetting resins or adhesives may be used.

[0132] Furthermore, while the aforementioned adhesive material can be used to create an electrically lossy material by forming an adhesive around a conductive particulate filler, the present invention is not limited thereto. For example, the conductive particles can be impregnated into the formed matrix material or coated onto the formed matrix material, such as by applying a conductive coating to a plastic or metal part. As used herein, the term "adhesive" encompasses a matrix that encapsulates, is impregnated with, or otherwise serves as a retaining material for the filler.

[0133] Preferably, the filler will be present in a sufficient volume percentage to allow for the creation of a conductive path from particle to particle. For example, when metal fibers are used, the fibers may be present in a volume percentage of about 3% to 40%. The amount of filler will affect the conductive properties of the material.

[0134] Filling materials are commercially available, for example from Celanese under the trade name Materials sold as such, which may be filled with carbon fibers or stainless steel filaments. Adhesive preforms filled with lossy conductive carbon, such as the lossy materials sold by Techfilm of Billerica, Massachusetts, USA, may also be used. Such preforms may include an epoxy adhesive filled with carbon fibers and / or other carbon particles. The adhesive surrounds the carbon particles, which may serve as reinforcement for the preform. Such preforms may be inserted into connector sheets to form all or part of a housing. In some embodiments, the preforms may be adhered by an adhesive in the preform, which may be cured during a heat treatment process. In some embodiments, the adhesive may take the form of a separate conductive or non-conductive adhesive layer. In some embodiments, the adhesive in the preform may be used alternatively or additionally to secure one or more conductive elements, such as a foil, to the lossy material.

[0135] Various forms of reinforcing fibers can be used, either woven or non-woven, coated or uncoated. Non-woven carbon fiber is one suitable material. Other suitable materials such as custom blends sold by RTP Company may be used, as the invention is not limited in this respect.

[0136] In some embodiments, the lossy member can be manufactured by stamping a preform or a thin sheet of lossy material. For example, the insert can be formed by stamping an appropriate opening pattern from a preform as described above. However, other materials can be used instead of or in addition to such a preform. For example, a sheet of ferromagnetic material can be used.

[0137] However, lossy materials can also be formed in other ways. In some embodiments, the lossy member can be formed by interweaving layers of lossy and conductive materials, such as metal foil. The layers can be rigidly attached to each other, such as by using epoxy or other adhesives, or can be held together in any other suitable manner. The layers can be in the desired shape before being fastened together or can be stamped or otherwise formed after they are held together.

[0138] Figure 10 1 shows further details of the construction of the thin film module 100. The module 1000 may be representative of any module in a connector, such as Figure 7 and Figure 8 810D shown in FIG. Each module in modules 810A...810D can have the same overall structure, and some parts can be the same for all modules. For example, the contact tail area 820 and the mating contact area 840 can be the same for all modules. Each module can include a middle area 830, but the length and shape of the middle area 830 can vary depending on the location of the module in the sheet.

[0139] In the illustrated embodiment, the module 1000 includes a pair of signal conductors 1310A and 1310B ( Figure 13 ). Insulating housing portion 1100 is at least partially surrounded by reference conductors 1010A and 1010B. This subassembly can be held together in any suitable manner. For example, reference conductors 1010A and 1010B can have features that engage with each other. Alternatively or additionally, reference conductors 1010A and 1010B can have features that engage with insulating housing portion 1100. As another example, when components 900A and 900B are as shown Figure 7 The reference conductor can be held in place when fastened together as shown in FIG.

[0140] Figure 10 The exploded view of FIG1 shows that the mating contact area 840 includes sub-areas 1040 and 1042. Sub-area 1040 includes the mating contact portions of module 1000. When mated with pin module 300, the mating contact portions of the pin module will enter sub-area 1040 and engage the mating contact portions of module 1000. These components can be sized to support a "functional mating range" such that if modules 300 and 1000 are fully pressed together, the mating contact portions of module 1000 will slide along the pins of pin module 300 during mating by a distance equal to the "functional mating range."

[0141] The impedance of the signal conductors in sub-region 1040 will be primarily determined by the structure of module 1000. The separation of the pair of signal conductors and the separation of the signal conductors from reference conductors 1010A and 1010B will set the impedance. The dielectric constant of the material surrounding the signal conductors (in this embodiment, air) will also affect the impedance. According to some embodiments, the design parameters of module 1000 can be selected to provide a nominal impedance within region 1040. This impedance can be designed to match the impedance of the rest of module 1000, and in turn, can be selected to match the impedance of the printed circuit board or other parts of the interconnect system so that the connector does not create an impedance discontinuity.

[0142] If modules 300 and 1000 are in their standard mated position, which in this embodiment are fully pressed together, the pins will be located within the mating contacts of the signal conductors of module 1000. The impedance of the signal conductors in sub-region 1040 will still be primarily determined by the configuration of sub-region 1040, thereby providing an impedance matching that of the rest of module 1000.

[0143] There may be a sub-area 340 ( Figure 3In sub-region 340, the impedance of the signal conductors will be determined by the configuration of pin module 300. This impedance will be determined by the separation of signal conductors 314A and 314B, and the separation of signal conductors 314A and 314B from reference conductors 320A and 320B. The dielectric constant of insulating portion 410 will also affect the impedance. Therefore, these parameters can be selected to provide an impedance within sub-region 340 that can be designed to match the nominal impedance in sub-region 1040.

[0144] The impedance in sub-regions 340 and 1040, determined by the module's construction, is largely independent of any separation between the modules during mating. However, modules 300 and 1000 have sub-regions 342 and 1042, respectively, that interact with components of the mating module and can affect impedance. Because the positioning of these components affects impedance, impedance can vary depending on the separation of the mating modules. In some embodiments, these components are positioned to minimize changes in impedance regardless of separation distance, or by distributing changes across the mating area to minimize the impact of impedance changes.

[0145] When pin module 300 is fully pressed against module 1000, the components in sub-areas 342 and 1042 can combine to provide the rated mating impedance. Because the modules are designed to provide a functional mating range, the signal conductors within pin module 300 and module 1000 can mate even if the modules are separated by an amount equal to the functional mating range, such that the separation between the modules can result in a change in impedance relative to the rated value at one or more locations along the signal conductors in the mating area. Appropriate shaping and positioning of these components can reduce this change or reduce the effect of the change by distributing the change among portions of the mating area.

[0146] exist Figure 3 and Figure 10 In the embodiment shown in FIG, the sub-region 1042 is designed to overlap the pin module 300 when the module 1000 is fully pressed against the pin module 300. The protruding insulating members 1042A and 1042B are sized to fit within the spaces 342A and 342B, respectively. With the modules pressed together, the distal ends of the insulating members 1042A and 1042B abut against the surfaces 450 ( Figure 4). These distal ends can have a shape that is complementary to the tapered portion of surface 450 so that insulating members 1042A and 1042B fill spaces 342A and 342B, respectively. The overlap creates relative positions for the signal conductors, the dielectric, and the reference conductor, which can be proximate to structures within sub-region 340. These components can be sized to provide the same impedance as the impedance in sub-region 340 when modules 300 and 1000 are fully pressed together. When the modules are fully pressed together (in this example, the modules are in the standard mating position), the signal conductors will have the same impedance throughout the mating area consisting of sub-regions 340, 1040, and where sub-regions 342 and 1042 overlap.

[0147] These components may also be sized and may have material properties that provide impedance control based on the separation of modules 300 and 1000. Impedance control may be achieved by providing substantially the same impedance in sub-regions 342 and 1042, even if the sub-regions do not completely overlap, or by providing a gradual impedance transition regardless of how the modules are separated.

[0148] In the illustrated embodiment, impedance control is provided in part by protruding insulating members 1042A and 1042B, which completely or partially overlap module 300, depending on the separation between modules 300 and 1000. These protruding insulating members can reduce the magnitude of changes in the relative dielectric constant of the material surrounding the pins of pin module 300. Impedance control is also provided by protrusions 1020A and 1022A, and 1020B and 1022B, in reference conductors 1010A and 1010B. These protrusions affect the separation between portions of the signal conductor pair and reference conductors 1010A and 1010B in a direction perpendicular to the axis of the signal conductor pair. This separation, combined with other features such as the width of the signal conductors in these portions, can control the impedance of these portions so that it is close to the rated impedance of the connector or does not change abruptly in a manner that could cause signal reflections. Other parameters of either or both of the mating modules can be configured to provide such impedance control.

[0149] Go to Figure 11 , further details of exemplary components of module 1000 are shown. Figure 11 FIG1 is an exploded view of module 1000, excluding reference conductors 1010A and 1010B. In the illustrated embodiment, insulating housing portion 1100 is fabricated from multiple components. Central member 1110 may be molded from an insulating material. Central member 1110 includes two recesses 1212A and 1212B into which conductive elements 1310A and 1310B, forming a pair of signal conductors in the illustrated embodiment, may be inserted.

[0150] Covers 1112 and 1114 can be attached to opposite sides of the central member 1110. Covers 1112 and 1114 can help retain the conductive elements 1310A and 1310B within the recesses 1212A and 1212B and with controlled separation from the reference conductors 1010A and 1010B. In the illustrated embodiment, covers 1112 and 1114 can be formed from the same material as the central member 1110. However, the materials are not required to be the same, and in some embodiments, different materials can be used to provide different relative permittivities in different regions to provide a desired impedance for the signal conductors.

[0151] In the illustrated embodiment, grooves 1212A and 1212B are configured to maintain a pair of signal conductors edge-coupled at the contact tails and mating contact portions. Within the main portion of the middle portion of the signal conductors, the pair of signal conductors remains broadside coupled. To transition between edge coupling at both ends of the signal conductors and broadside coupling in the middle portion, a transition region can be included in the signal conductors. The grooves in the central member 1110 can be shaped to provide transition regions in the signal conductors. Protrusions 1122, 1124, and 1128 on the covers 1112 and 1114 can press the conductive elements against the central portion 1110 in these transition regions.

[0152] exist Figure 11 In the embodiment shown in FIG, the transition between broadside coupling and edge coupling can be seen in region 1150. At one end of this region, the signal conductors are aligned edge-to-edge along the column direction in a plane parallel to the column direction. Turning region 1150 sideways toward the middle, the signal conductors bend in opposite directions perpendicular to the planes and toward each other. Thus, at the ends of region 1150, the signal conductors are in different planes parallel to the column direction. The middle portions of the signal conductors are aligned perpendicular to these planes.

[0153] Region 1150 includes a transition region such as 822 or 842 where the waveguide is formed by the reference conductor transitioning from the widest dimension of the middle portion to the narrower dimension plus a portion of the narrower middle region 830. Thus, at least a portion of the waveguide formed by the reference conductor in region 1150 has the same widest dimension W as in the middle region 830. Having at least a portion of the waveguide having a physical transition in the narrower portion reduces energy coupling into undesired waveguide propagation modes.

[0154] Having full 360 degree shielding for the signal conductors in region 1150 can also reduce energy coupling into undesired waveguide propagation modes. Thus, in the illustrated embodiment, the opening 832 does not extend into region 1150.

[0155] Figure 12Further details of module 1000 are shown. In this view, conductive elements 1310A and 1310B are shown separated from central member 1110. For clarity, covers 1112 and 1114 are not shown. In this view, transition region 1312A between contact tail 1330A and middle portion 1314A is visible. Similarly, transition region 1316A between middle portion 1314A and mating contact portion 1318A is also visible. Similar transition regions 1312B and 1316B are visible for conductive element 1310B, allowing for edge coupling at contact tail 1330B and mating contact portion 1318B, as well as broadside coupling at middle portion 1314B.

[0156] The mating contacts 1318A and 1318B can be formed from the same metal sheet as the conductive elements. However, it should be understood that in some embodiments, the conductive elements can be formed by attaching separate mating contacts to other conductors to form an intermediate portion. For example, in some embodiments, the intermediate portion can be a cable, and the conductive elements are formed by terminating the cable with the mating contacts.

[0157] In the illustrated embodiment, the mating contact portion is tubular. This shape can be formed by stamping the conductive element from sheet metal and then rolling the mating contact portion into a tubular shape. The outer circumference of the tube can be large enough to accommodate the pins of the mating pin module, but can fit snugly around the pins. The tube can be divided into two or more sections to form a flexible beam. Figure 12 Two such beams are shown in FIG. A ridge or other protrusion may be formed in the distal portion of the beam to create a contact surface. These contact surfaces may be coated with gold or other conductive, ductile material to improve the reliability of the electrical contact.

[0158] When the conductive elements 1310A and 1310B are installed in the central member 1110, the mating contact portions 1318A and 1318B fit within the openings 1220A and 1220B. The mating contact portions are separated by a wall 1230. The distal ends 1320A and 1320B of the mating contact portions 1318A and 1318B can be aligned with openings in the platform 1232, such as opening 1222B. These openings can be positioned to receive pins of the mating pin module 300. The wall 1230, platform 1232, and insulating protruding members 1042A and 1042B can be formed as part of the portion 1110, such as in a single molding operation. However, any suitable technique can be used to form these components.

[0159] Figure 12Other techniques are shown as an alternative or in addition to the above techniques for reducing the energy propagating in undesired modes within the waveguide formed by the reference conductor in the transition region 1150. Conductive or lossy materials can be incorporated into each module to reduce the excitation of undesired modes or suppress undesired modes. Figure 12 For example, loss region 1215 is shown. Loss region 1215 can be configured to drop along the centerline between signal conductors 1310A and 1310B in some or all regions 1150. Because signal conductors 1310A and 1310B bend in different directions through this region to perform the edge-to-broadside transition, loss region 1215 may not be defined by surfaces that are parallel or perpendicular to the walls of the waveguide formed by the reference conductor. Instead, the loss region may be formed as a surface that is equidistant from the edges of signal conductors 1310A and 1310B as the signal conductors twist through region 1150. In some embodiments, loss region 1215 may be electrically connected to the reference conductor. However, in other embodiments, loss region 1215 may be left floating.

[0160] Although shown as lossy regions 1215, similarly positioned conductive regions can also reduce energy coupling into undesirable waveguide modes that reduce signal integrity. In some embodiments, such a conductive region having twisted regions 1150 can be connected to a reference conductor. While not being limited to any particular theory of operation, a conductor that acts as a separation between signal conductors and thereby twists to follow the twist of the signal conductors in the transition region can couple ground currents into the waveguide, thereby reducing undesirable modes. For example, current can be coupled to flow in a different mode through the walls of the reference conductor parallel to the broadside-coupled signal conductors, rather than exciting a common mode.

[0161] Figure 13 The positioning of conductive members 1310A and 1310B forming a pair of signal conductors 1300 is shown in greater detail. In the illustrated embodiment, conductive members 1310A and 1310B each have an edge and a broadside located between these edges. Contact tails 1330A and 1330B are aligned in a column 1340. With this alignment, the edges of conductive elements 1310A and 1310B face each other at contact tails 1330A and 1330B. Other modules in the same wafer will similarly have contact tails aligned along column 1340. Contact tails of adjacent wafers will be aligned in parallel columns. The spaces between the parallel columns create routing channels on the printed circuit board to which the connector is attached. Mating contact portions 1318A and 1318B are aligned along column 1344. Although the mating contact portions are tubular, the portion of conductive elements 1310A and 1310B to which the mating contact portions 1318A and 1318B are attached is edge-coupled. Thus, the mating contact portions 1318A and 1318B may similarly be referred to as edge coupled.

[0162] In contrast, the intermediate portions 1314A and 1314B are aligned with the broad sides of the intermediate portions facing each other. The intermediate portions are aligned in the direction of row 1342. Figure 13 In the example of FIG. 1 , the conductive elements for a right angle connector are shown as being bent at a right angle between column 1340, which represents the point of attachment to the daughter card, and column 1344, which represents the location for mating pins attached to the backplane connector.

[0163] In conventional right-angle connectors where edge-coupled pairs are used in wafers, within each pair, the conductive elements in the outer rows at the daughter card are longer. Figure 13 In FIG, conductive element 1310B is attached to the outer rows of the daughter card. However, because the middle sections are broadside coupled, middle sections 1314A and 1314B are parallel throughout the transverse right-angled portion of the connector, leaving no conductive elements in the outer rows. Thus, the different electrical path lengths do not introduce offset.

[0164] In addition, Figure 13 , other techniques for avoiding skew are described. Although contact tails 1330B of conductive element 1310B are located in an outer row along column 1340, the mating contact portions of conductive element 1310B (mating contact portions 1318B) are located in a shorter, inner row along column 1344. Conversely, contact tails 1330A of conductive element 1310A are located in an inner row along column 1340, but mating contact portions 1318A of conductive element 1310A are located in an outer row along column 1344. Consequently, the longer path length for signals moving closer to contact tails 1330B relative to 1330A can be offset from the shorter path length for signals moving closer to mating contact portions 1318B relative to 1318A. Thus, the illustrated techniques can further reduce skew.

[0165] Figure 14A and Figure 14B Edge coupling and broadside coupling within the same pair of signal conductors are shown. Figure 14A This is a side view shown along the direction of row 1342. Figure 14B is an end view shown along the direction of column 1344. Figure 14A and Figure 14B The transition between the edge-coupled mating contact portions and contact tails and the broadside-coupled intermediate portions is shown.

[0166] Other details of the mating contact portions 1318A and 1318B are also visible. The tubular portion of the mating contact portion 1318A is Figure 14A The tubular portion of the mating contact portion 1318B is visible in the view shown and is Figure 14BThe beams (of which beams 1420 and 1422 in the mating contact portion 1318B are numbered) are also visible.

[0167] The inventor has recognized and understood Figure 6 The member 630 in FIG. 6 is suitable for many applications, but when used over a large area, it is likely that small gaps will open between portions of the conductive shield. For example, small gaps may open in various locations between a conductive portion on the member 630 and a surface ground pad on the PCB and / or between a conductive portion on the member 630 and a reference conductor 1010 on the thin film module 810. Small gaps can undesirably affect signal integrity and introduce signal crosstalk, particularly when used in ultra-high density interconnect systems carrying ultra-high frequency signals. Small gaps can cause energy from the differential modes supported by the differential conductors to leak out of the waveguide formed by the reference conductor and result in signal loss. Small gaps may also result in unwanted mode conversion at the connector interface with the PCB. In combination Figure 15 pass Figure 17B and FIG. 22A to FIG. 22B A flexible shield that can mitigate signal loss and mode conversion is described.

[0168] Figure 15 An embodiment of a two-piece flexible shield 1500 that can be used with multiple thin-sheet modules is shown. To simplify the drawing, the flexible shield is shown for use with six differential conductor pairs, but the present invention is not limited to six. The flexible shield can be used with, for example, 12, 16, 32, 64, 128 differential conductor pairs, or any other suitable number of differential conductor pairs.

[0169] According to some embodiments, the flexible shield 1500 may include an insulating portion 1504 and a flexible conductive member 1506. The insulating portion may be formed from a hard or solid polymer, and the flexible conductive member may be formed from a conductive elastomer. The insulating portion 1504 may be configured to receive the contact tails of the thin film module 1310. The flexible conductive member may be configured to abut the insulating portion and provide an electrical connection between the reference conductor 1010 on the thin film module 1310 and a reference pad (not shown) on the PCB. In some cases, the insulating portion 1504 may not be used, and the flexible conductive member 1506 may abut the end of the thin film module.

[0170] The insulating portion 1504 may be a molded or cast component and may be planar in some embodiments. In some implementations, the insulating portion may include, for example, Figure 15 and having a first level 1508 that can be substantially planar. In some cases, as Figure 16As shown, the first stage can have an opening 1512 to receive the end of the wafer module 130. The opening 1512 can be sized and shaped to receive a tab 1502 extending from the wafer module and connected to the wafer module's reference conductor 1010. As shown, the tab 1502 extends above the reference conductor 1010. The tab can be electrically connected to a surface pad 1910 on the printed circuit board through the flexible shield 1500. In some embodiments, the tab can be adjacent to the contact tail of a signal conductor also extending from the connector. In the illustrated embodiment, two tabs are aligned parallel to the column 1340 at one edge of the contact tail area 820, and two tabs are aligned parallel to the column 1340 at the opposite edge of the contact tail area 820. The one or more tabs can be formed and arranged in any suitable manner.

[0171] The insulating portion can include a plurality of raised islands 1510 extending a distance d1 from the first level. These islands can have walls 1516 extending from the first level 1508 and supporting the islands above the first level. Channels or recesses 1518 can be formed on the edges of the islands 1510, sized and shaped to receive the tabs 1502 of the thin-film module. The edges of the islands at the recesses 1518 can provide a backing for the ends of the tabs 1502, thereby applying lateral forces to the tabs. When the insulating portion is mounted above the ends of the thin-film module, the ends of the tabs 1502 can be below or substantially flush with the surface of the island facing the PCB (not shown) to which the connector is connected.

[0172] The insulating portion 1504 may include contact slots 1514A, 1514B, and 1515 formed in the island and extending through the island. The contact slots may be sized and positioned to receive the contact tails 610 and allow the contact tails to pass through. In some embodiments, multiple contact slots may have two closed ends. In some embodiments, multiple contact slots may have one closed end and one open end. For example, each island 1510 may have four contact slots with one open end to accommodate four contact tails of a thin film module. In some embodiments, the aspect ratio of the contact slots may be between 1.5:1 and 4:1. The contact slots 1514A, 1514B may be arranged in a repeating pattern of a sub-pattern. For example, each island 1510 may have a copy of the sub-pattern.

[0173] In some embodiments, at least the island 1510 of the insulating portion 1504 can be formed from a material having a dielectric constant that establishes the desired impedance for the signal conductors in the connector's mounting interface. In some embodiments, the relative dielectric constant can be in the range of 3.0 to 4.5. In some embodiments, the relative dielectric constant can be higher, such as in the range of 3.4 to 4.5. In some embodiments, the relative dielectric constant of the island can be in one of the following ranges: 3.5 to 4.5, 3.6 to 4.5, 3.7 to 4.5, 3.8 to 4.5, 3.9 to 4.5, or 4.0 to 4.5. This relative dielectric constant can be achieved by selecting the adhesive material and filler. For example, known materials can be selected to provide a relative dielectric constant of up to 4.5. Relative dielectric constants within these ranges can result in the island having a dielectric constant that is higher than the dielectric constant of the connector's insulating housing. In some embodiments, the island can have a relative dielectric constant that is at least 0.1, 0.2, 0.3, 0.4, 0.5, or 0.6 higher than that of the connector housing. In some embodiments, the difference in relative dielectric constant will be in the range of 0.1 to 0.3, or 0.2 to 0.5, or 0.3 to 1.0.

[0174] like Figure 17A and Figure 17B As shown, the flexible conductive member 1506 can include a plurality of openings 1520 sized and shaped to receive the island 1510 when mounted to the insulating portion 1504. In some embodiments, the openings 1520 are sized and shaped such that an inner wall of the flexible conductive member 1506 contacts the reference protrusion 1502 and the reference contact tail extending through the island 1510 when mounted over the insulating portion 1504.

[0175] In its uncompressed state, flexible conductive member 1506 has a thickness d2. In some embodiments, thickness d2 can be approximately 20 mils, or between 10 and 30 mils in other embodiments. In some embodiments, d2 can be greater than d1. Because the thickness d2 of the flexible conductive member is greater than the height d1 of island 1510, when the connector is pressed against the PCB engaging the contact tails, the flexible conductive member is compressed by a normal force (a force perpendicular to the plane of the PCB). As used herein, "compression" refers to the dimensional reduction of a material in one or more directions in response to the application of a force. In some embodiments, for example, the compression can be in the range of 3% to 40%, or any value or sub-range within this range, including, for example, a range between 5% and 30%, between 5% and 20%, or between 10% and 30%. Compression can result in a change in the height of the flexible conductive member (e.g., d2) in a direction perpendicular to the surface of the printed circuit board. This dimensional reduction can be caused by a reduction in the volume of the flexible member, such as when the flexible member is made of an open-cell foam material, as air is expelled from the pores of the material when force is applied to the material. Alternatively or additionally, height variations in one dimension may be caused by displacement of material.In some embodiments, the material forming the flexible conductive member may expand laterally parallel to the surface of the printed circuit board when compressed in a direction perpendicular to the surface of the circuit board.

[0176] Due to the location of opening 1520, the flexible conductive element can have different characteristic dimensions at different regions. In some embodiments, thickness d2 may not be uniform across the entire member, but may depend on the characteristic dimensions of the member. For example, region 1524 may have a larger size and / or a larger area than region 1522. Thus, when the connector is pressed against the PCB, the normal force may cause less compression at region 1524 than at region 1522. To achieve similar lateral expansion and thus consistent contact with the reference protrusion and the reference contact tail, d2 around region 1524 may be smaller than d2 around region 1522.

[0177] The compression of the flexible conductive member can accommodate the non-flat reference pad on the PCB surface and induce a lateral force within the flexible conductive member that causes the flexible conductive member to expand laterally to press against the reference protrusion 1502 and the reference contact tail. In this way, gaps between the flexible conductive member and the reference protrusion and reference contact tail, as well as between the flexible conductive member and the reference pad on the PCB, can be avoided.

[0178] Suitable flexible conductive members 1506 can have a volume resistivity between 0.001 and 0.020 ohm-cm. Such materials can have a hardness on the Shore A scale ranging from 35 to 90. Such materials can be conductive elastomers, such as silicone elastomers filled with conductive particles such as silver, gold, copper, nickel, aluminum, nickel-coated graphite, or combinations or alloys thereof. Non-conductive fillers, such as glass fibers, can also be present. Alternatively or additionally, the conductive flexible material can be partially conductive or exhibit resistive losses, such that it would be considered a lossy material as described above. This can be achieved by filling all or part of the elastomer or other adhesive with different types or amounts of conductive particles to provide a volume resistivity associated with the materials described above as "lossy." In some embodiments, the conductive flexible member can have an adhesive backing so that it can be adhered to the insulating portion 1504. In some embodiments, the flexible conductive member 1506 can be a die cut from a sheet of conductive elastomer having suitable thickness, electrical, and other mechanical properties. In some embodiments, the flexible conductive member can be cast in a mold.In some embodiments, the flexible conductive member 1506 of the flexible shield 1500 can be formed from a conductive elastomer and comprise a single layer of material.

[0179] Figure 16 The insulating portion 1504 of two wafer modules 1310 attached to a connector is shown in accordance with some embodiments. The contact tails 610 of the wafer modules pass through contact slots 1514A and 1514B and are electrically isolated from each other by the dielectric material of the island 1510 within the insulating portion. The protrusion 1502 passes through the opening 1512 and abuts the notch 1518 in the wall 1516 on the island. The protrusion is electrically isolated from the differential pair of contact tails by the dielectric material of the insulating portion.

[0180] Figure 17A and Figure 17B A conductive flexible member 1506 is shown mounted around island 1510 in accordance with some embodiments. When the connector is pressed onto the PCB, protrusion 1502 can be electrically connected to a surface pad on the printed circuit board via the conductive flexible member. As described above, the flexible conductive member can be compressed in a direction perpendicular to the surface of the PCB when the connector is pressed onto the PCB and expand laterally toward island wall 1516, abutting protrusion 1502 and the reference contact tail. Figure 17B The view of FIG. 15A shows the circuit board-facing surface of the flexible shield 1500 and shows four reference contact tails and differential contact tails extending through the contact slots 1514A and 1514B of the two wafer modules. The area between the islands 1510 is filled with a conductive flexible material.

[0181] In the illustrated embodiment, each sub-pattern includes a pair of contact slots 1514A, 1514B aligned with the longer dimension of the line and at least two additional contact slots 1515. The longer dimension of the contact slots 1515 is arranged in a parallel line perpendicular to the line of the pair of contact slots 1514A, 1514B. In some embodiments, the contact tails 610 of each module are arranged in a pattern in which the contact tails of the signal conductors are located in the center and the contact tails of the shield are located at the periphery. In some embodiments, the contact slots 1514A, 1514B are positioned to receive the contact tails 610 carrying the signal conductors, and the contact slots 1515 are positioned to receive the contact tails carrying the reference conductors.

[0182] Figure 18 A connector footprint 1800 is shown on a printed circuit board 1802 to which a connector as described herein may be mounted, according to some embodiments. Figure 18 A pattern of vias 1805 , 1815 in a printed circuit board is shown, to which the contact tails of the connector 600 may be mounted, as described above. Figure 18 The pattern of vias shown in may correspond to, for example, Figure 15 The module footprint 1820 of a thin-film module may include a via pattern that is repeated on the surface of the PCB 1802 to form a connector footprint. Figure 15 As is the case with the connector shown in , there may be more than six module footprints for larger connectors.

[0183] The module footprint 1820 can include a pair of vias 1805A and 1805B positioned to receive the contact tails of a pair of differential signal conductors. One or more reference or ground vias 1815 can be arranged around the pair of signal vias. For the illustrated embodiment, the pair of reference vias is located at opposite ends of the pair of signal vias. The illustrated pattern arranges the reference vias in columns aligned with the columns of the connector, with routing channel areas 1830 between the columns. This configuration also provides a relatively wide routing channel area within the printed circuit board that is easily accessible by the differential signal pairs, enabling high-density interconnects with desired high-frequency performance.

[0184] Figure 19 A connector footprint 1900 is shown on a printed circuit board 1902 configured for use with the flexible shield 1500 in accordance with some embodiments. Figure 19 The implementation method and Figure 18The embodiment differs in that each module footprint 1920 includes a conductive surface pad 1910. According to some embodiments, the surface pad 1910 can be electrically connected to the reference via 1815 (e.g., around the via) and thereby connected to one or more internal reference layers (e.g., a ground plane) of the printed circuit board. Holes 1912 can be formed in the surface pad so that the vias that receive the contact tails of the differential signal conductors are electrically isolated from the surface pad. In the embodiment shown, the holes are elliptical in shape. However, the holes are not required to be elliptical in shape, and in some embodiments, different shapes can be used, such as rectangular, circular, hexagonal, or any other suitable opening shape. In some implementations, the surface pad 1910 can be formed from a single continuous layer of conductive material (e.g., copper or a copper alloy).

[0185] The inventors have recognized and appreciated that in embodiments in which a printed circuit board includes a conductive surface layer, such as surface pad 1910, that contacts a conductive structure that is grounded within the printed circuit board by connecting the ground structure within a connector or other component to a ground within the printed circuit board, a shadow via can be positioned to shape the current flowing through the conductive surface layer. The conductive shadow via can be placed near a contact point on the conductive surface layer of a component that is connected to the ground structure of the connector. This positioning of the shadow via limits the length of the primary conductive path from the contact point to the via that couples current flowing into the internal ground layer of the printed circuit board. Limiting the current in the ground conductor to flow in a direction parallel to the circuit board surface, which is perpendicular to the direction of signal current flow, can improve signal integrity.

[0186] Figure 20 A connector footprint 2000 is shown on a printed circuit board 2002 configured for use with a flexible shield according to another embodiment. Figure 20 The implementation method and Figure 19 1805A, 1805B. The embodiment differs in that a pair of shadow vias 2010 are incorporated into the module footprint 2020 adjacent to the vias for the differential signal conductors 1805A, 1805B. The shadow vias 2010 can be electrically connected to the surface pads 1910. The shadow vias can also be electrically connected to one or more internal reference layers (e.g., a ground plane) of the printed circuit board, such that the surface pads are also electrically connected to the ground plane through the shadow vias. When the connector is installed, the conductive flexible material 1506 can be pressed against the reference tab 1502 and the surface pads 1910 above the shadow vias 2010, thereby creating a substantially direct conductive path from the reference tab, through the flexible shield, to the surface pads, to the shadow vias, and then to one or more reference layers of the printed circuit board.

[0187] Shadow vias 2010 can be located near signal vias 1805A and 1805B. In the example shown, a pair of shadow vias 2010 are located on a first line 2022 perpendicular to a second line 2024 that passes through signal vias 1805A and 1805B in the direction of column 1340. First line 2022 can be located between signal vias 1805A and 1805B, such that the pair of shadow vias are equally spaced from signal vias 1805A and 1805B. In embodiments where more shadow vias are included in each module footprint 2020, the shadow vias can be aligned with the signal vias in a direction perpendicular to first line 2022.

[0188] Shadow vias 2022 may at least partially overlap with holes 1912. In other embodiments, each module footprint 2020 may include more than one pair of shadow vias. Furthermore, the shadow vias may be implemented as one or more circular shadow vias or one or more slot-shaped shadow vias.

[0189] In some embodiments, shadow via 2010 can be smaller than the vias used to receive contact tails of the connector (e.g., smaller than signal vias 1805A, 1805B, and / or reference via 1815). In embodiments where the shadow vias do not receive contact tails, the shadow vias can be filled with a conductive material during the manufacture of the printed circuit board. As a result, the unplated diameter of the shadow vias can be smaller than the unplated diameter of the vias receiving contact tails. The diameter can be, for example, in the range of 8 mils to 12 mils, or at least 3 mils smaller than the unplated diameter of the signal or reference vias.

[0190] In some embodiments, the shadow vias can be positioned so that the length of the conductive path through the surface layer to the nearest shadow via coupling the conductive surface layer to the internal ground layer can be less than the thickness of the printed circuit board. In some embodiments, the conductive path through the surface layer can be 50%, 40%, 30%, 20%, or 10% less than the thickness of the circuit board.

[0191] In some embodiments, the shadow vias can be positioned to provide a conductive path through the surface layer that is less than the average length of the conductive path of a signal between a connector, or other component mounted on the circuit board, and an inner layer of the circuit board to which the signal via is connected to a conductive trace. In some embodiments, the shadow vias can be positioned so that the conductive path through the surface layer can be 50%, 40%, 30%, 20%, or 10% less than the average length of the signal path.

[0192] In some embodiments, the shadow vias may be positioned to provide a conductive path through the surface layer of less than 5 mm. In some embodiments, the shadow vias may be positioned so that the conductive path through the surface layer may be less than 4 mm, 3 mm, 2 mm, or 1 mm.

[0193] Figure 21A A plan view of a connector footprint 2100 on a printed circuit board 2102 is shown, according to some implementations. For the illustrated embodiment, the outline of the flexible conductor member 1506 is shown by dashed lines. In the illustrated embodiment, the conductive surface pad 2110 is patterned with additional structure surrounding each module footprint 2120. For example, there may be multiple repeating module sub-patterns connected by bridges 2106. Between the bridges may be gaps 2104, into which the flexible conductive member can deform. The bridges can be arranged to create short conductive paths between the flexible conductive member and reference and shadow vias connected to the internal reference or ground plane of the printed circuit board. For example, the bridges 2106 can be patterned to conductively connect adjacent reference and shadow vias. By having raised bridges near the reference and shadow vias, and allowing the flexible conductive member to deform into the gaps 2104, the electrical connection between the flexible conductive member and the reference and shadow vias can be improved near the vias. In some embodiments, the thickness d3 of the surface pad can be between 1 mil and 4 mils. In some embodiments, the thickness of the surface pad can be between 1.5 mils and 3.5 mils.

[0194] In the flexible conductive member 1506, each sub-pattern 2120 can be aligned with a corresponding opening 1520. In some embodiments, the module's reference via 1815 can be within the opening 1520, while in other embodiments, the reference via can be partially within the opening and partially covered by the flexible conductive member 1506. In some embodiments, the module's reference via 1815 can be completely covered by the flexible conductive member. In some embodiments, the module's shadow via 1805 can be within the opening 1520, while in other embodiments, the shadow via can be partially within the opening and partially covered by the flexible conductive member. In some embodiments, the module's shadow via can be completely covered by the flexible conductive member.

[0195] Figure 21B Shown along Figure 21A, a cross-sectional view taken along the cut lines shown in FIG. Bridges 2106 and gaps 2104 may alternate across the surface of printed circuit board 2102. When installed, flexible conductive member 1506 may extend into the gap and press against the surface of the bridge near reference protrusion 1502 and the reference contact tail. To ensure reliable contact, the flexible conductive element may be compressed by an amount sufficient to account for any changes in the surface height of the circuit board and any changes in the separation between the connector and the circuit board when the connector is inserted. In some embodiments, the deformation of the flexible conductive member may be in the range of 1 mil to 10 mils. The gap provides a volume within which the flexible conductive element can deform, thereby allowing for proper compression of the flexible conductive member and thereby providing a more uniform amount of contact force between the flexible conductive member and the reference protrusion and pads on the printed circuit board. It should be understood that the gap that enables sufficient compression of the flexible conductive member can be created in any suitable manner. In other embodiments, the gap may be created by removing a portion of the connector housing, such as first stage 1508 of insulating portion 1504, for example.

[0196] Figure 22A A partial plan view of the circuit board-facing surface of the flexible shield 2200 mounted to the connector is shown, illustrating four reference contact tails, reference protrusion 1502, and contact tails 1330A and 1330B of the differential signal conductors. In some embodiments, the flexible shield 2200 may include only the flexible conductive member 2206 and may be formed from a conductive elastomer as described above. In some embodiments, a retaining member 2210 (or multiple retaining members abutting at dashed line 2212) may be placed over the ends of the wafer modules and inserted into the connector to retain the ends of the wafer modules in the array. The retaining member 2210 may be formed from an insulating, rigid or hard polymer. The retaining member 2210 may include an opening 2204 sized and positioned to receive the ends of the wafer modules 1000 and may not include the island 1510. In some embodiments, a retaining member may not be used. Instead, the flexible conductive member 2206 may contact the member 900 used to retain the wafer modules 1000.

[0197] Figure 22B Shown along Figure 22A. The contact tail 1330A of the differential signal conductor can be isolated from the protrusion 1502 by the insulating housing 1100. When installed, the flexible conductive member 2206 can be pressed against the retainer 2210 (or member 900) and deformed laterally to press against the protrusion 1502 and / or the reference contact tail. In the example shown, the insulating housing 1100 is extruded from the retainer so that it can provide backing for the end of the protrusion. In some embodiments, the retainer can have a portion that fills the area shown as the opening 2204 and has a designed height to provide backing for the end of the protrusion.

[0198] Figure 23 pass Figure 17A The cross-sectional view marked in the center plane 23 shows further details of the thin-sheet module with the flexible shield 1506 attached. An organizer 2304 can be placed over the ends of the thin-sheet module and inserted into the connector to hold the ends of the thin-sheet module in the array. The organizer can be the insulating portion 1504 or the retaining member 2210. The organizer can include an opening 2306 that is sized and positioned to receive the conductive elements 1310A, 1310B held in the recess of the insulating housing 1100. To accommodate tolerances, the opening 2306 can be larger than the contact tails of the conductive elements 1310A, 1310B, which remain within the opening 2306.

[0199] In addition, in the illustrated embodiment, the contact tails of the conductive element are press-fit and have a neck 2302 that occupies a smaller space than the opening 2306. The inventors have recognized and understood that the air-filled space left in the opening may cause an impedance spike at the mounting interface of the connector to the PCB (not shown). To compensate for the impedance spike, a material having a higher dielectric constant than the dielectric constant of the insulating housing 1100 can be used to form an organizer. For example, the insulating housing can be formed from a material with a relative dielectric constant less than 3.5. The organizer can be formed from a material having a relative dielectric constant greater than 4.0, for example, in the range of 4.5 to 5.5. In some embodiments, the organizer can be formed by adding a filler to a polymer binder. For example, the filler can be a sufficient amount of titanium dioxide to obtain a relative dielectric constant within the desired range.

[0200] Figure 24 is an isometric view of two sheet modules 2400A and 2400B according to some embodiments. Figure 8 The differences between the sheet modules 810A through 810D in FIG. 8 include that the sheet modules 2400A and 2400B include additional protrusions 2402A and 2402B extending from the reference conductors 1010A and 1010B, respectively.

[0201] In some embodiments, protrusions 2402A and 2402B can be elastic and can be deformed to accommodate manufacturing variations in the separation between the board and the connector when the connector is mated with the board. The protrusions can be made of any suitable flexible conductive material (e.g., superelastic and shape memory materials). Reference conductor 1010 can include protrusions of various sizes and shapes, such as 2420A, 2420B, and 2420C. These protrusions affect the separation between portions of the signal conductor pair and reference conductors 1010A and 1010B in a direction perpendicular to the axis of the signal conductor pair. This separation, combined with other characteristics such as the width of the signal conductor in those portions, can control the impedance in those portions so that it approaches the nominal impedance of the connector or does not change dramatically in a manner that may cause signal reflections.

[0202] In some embodiments, a flexible shield can be implemented as a conductive structure positioned between the tails of signal conductors in the space between the mating surface of the connector and the upper surface of the printed circuit board. The effectiveness of the shield can be increased when the conductive portion is electrically coupled to a flexible portion that ensures reliable connection of the flexible shield to ground structures in the connector and / or printed circuit board over substantially all areas of the connector.

[0203] Figure 25A is an isometric view of a flexible shield 2500 that may be used with a plurality of sheet modules according to some embodiments. To simplify the drawing, the flexible shield is shown for use with an 8x4 array of sheet modules, but the invention is not limited to this array size.

[0204] Figure 25B yes Figure 25A FIG2 is an enlarged plan view of the area marked 25B in FIG2 , which may correspond to one of the plurality of thin modules in the connector. The flexible shield may include a conductive body portion 2504 having a plurality of flexible fingers 2516. The flexible fingers 2516 may be elongated beams. Each beam may have a proximal end integral with the conductive body portion and a free distal end.

[0205] The conductive body portion 2504 may include a plurality of openings 2506 of a first size through which the contact tails of the pair of differential signal conductors 1310A and 1310B pass, and a plurality of openings 2508 of a second size through which the contact tails of the reference conductor pass. The flexible fingers 2516 may be resilient in a direction that may be substantially parallel to the contact tails of the signal conductors. Alternatively or additionally, the flexible fingers may be resilient in a direction in which the contact tails of the connector are inserted into the openings.

[0206] In some embodiments, the openings 2506 and 2508 can be arranged in a repeating pattern of sub-patterns. Each sub-pattern can correspond to a corresponding thin film module. Each sub-pattern can include at least one opening 2506 for a signal conductor to pass through without contacting the conductive body portion, so that the signal conductor can be electrically isolated from the flexible shield. Each sub-pattern can include at least one opening 2508 for a reference conductor to pass through. The openings 2508 can be positioned and sized so that the reference conductor can be electrically connected to the conductive body portion and therefore electrically connected to the flexible shield. In the illustrated example, the opening 2506 is an ellipse having a major axis 2512 and a minor axis 2514. The opening 2508 is a slot having a ratio between the longer dimension 2518 and the shorter dimension 2520 of at least 2:1. Figure 25B The sub-pattern shown has four openings 2508 with their longer dimensions arranged in parallel lines perpendicular to the longer axes of the openings 2506 .

[0207] In some embodiments, the conductive body portion 2504 can include a plurality of openings 2502. Each opening 2502 can have a flexible finger extending from an edge 2522 of the opening. Such openings can be created by a stamping and forming operation in which the flexible beams 2516 are cut from the body portion 2504.

[0208] Other openings or features may be present in the body portion 2504. In some embodiments, the openings may be sized and positioned to allow the protrusions 2402A and 2402B to pass through, allowing the conductive body portion to electrically connect to the reference conductor of the wafer module. Alternatively or additionally, the opening 2508 may have at least one dimension that is smaller than the corresponding dimension of the reference conductor inserted into the opening. The body portion 2504 adjacent to the opening may be shaped so that when the reference conductor is inserted into the opening, it bends or deforms, allowing the reference conductor to be inserted, but once inserted, provides a contact force on the reference conductor, establishing an electrical connection between the reference conductor and the body portion 2504. This electrical connection may be 10 ohms or less, for example, between 10 ohms and 0.01 ohms. In some embodiments, the connection may be 5 ohms, 2 ohms, 1 ohm, or less. In some embodiments, the contact may be between 2 ohms and 0.1 ohms. Such contact may be formed by cutting from the body portion 2504 adjacent the opening as a cantilever beam or torsion beam fixed at both ends to the body portion 2504. Alternatively, the body portion may be shaped with an opening defined by a section that is compressed when the reference conductor is inserted.

[0209] The flexible shield 2500 can be made of a material having a desired conductivity for the current path. Suitable conductive materials for at least a portion of the conductive body include metals, metal alloys, superelastics, and shape memory materials. In some embodiments, the flexible shield can be made of a first material coated with a second material having a greater conductivity than the first material.

[0210] In some embodiments, the flexible shield can be manufactured by stamping openings in a sheet of metal, which can be substantially planar. For example, the flexible fingers 2516 can be manufactured by cutting elongated beams from a sheet of metal, with their proximal ends attached to the sheet. In embodiments where the body portion is generally planar, the free distal ends will be bent out of the plane of the body portion. Conductive, flexible metals that can be formed in this manner using conventional stamping and forming techniques are well known in the art and are suitable for manufacturing flexible shields.

[0211] When the mounting surface of the connector is positioned on the surface of a printed circuit board, the beam can bend out of the plane of the conductive body portion 2504 by an amount exceeding the tolerance. With this shape of beam, once the connector is mounted on the printed circuit board, the free distal end of the beam will contact the surface of the printed circuit board, as long as the connector is within tolerance. In addition, the beam will be at least partially compressed, ensuring that the beam generates a contact force that ensures a reliable electrical connection. In some embodiments, the contact force will be in the range of 1 Newton to 80 Newtons, or in some embodiments, between 5 Newtons and 50 Newtons, or between 10 Newtons and 40 Newtons, for example, between 20 Newtons and 40 Newtons.

[0212] Figure 26A corresponds to Figure 25B , a cross-sectional view taken along cut line 26 in FIG, illustrates a flexible shield mounted to a connector (e.g., connector 600) according to some embodiments. In an uncompressed state, the conductive body portion 2504 of the flexible shield 2500 can be spaced a distance d1 from a surface 2606 of a printed circuit board. In the example shown, each of the reference tails 1010A and 1010B extends through a corresponding opening 2508 and contacts the conductive body portion. Each of the flexible fingers 2516A and 2516B has a proximal end 2608 integral with the conductive body portion and a free distal end 2610 that presses against the surface of the printed circuit board to which the connector is to be mounted.

[0213] When the connector is pressed onto the surface 2606 of the PCB engaging the contact tails, the flexible shield is compressed by a normal force (a force substantially perpendicular to the PCB surface). Figure 26B yes Figure 26A25 is a cross-sectional view of a portion of the flexible shield in a compressed state. The PCB may have a ground pad on its surface. The ground pad may be connected to the ground plane of the PCB through a via. The conductive body portion 2504 may be pressed against the ground pad. The flexible fingers 2516A and 2516B may be deformed due to the normal force. The flexible shield may be a distance d2 away from the surface of the printed circuit board near the flexible finger 2516A and a distance d3 away from the surface of the printed circuit board near the flexible finger 2516B. It should be understood that d2 and d3 may be the same or different within a module depending on the variation in the gap between the connector and the PCB; even if d2 and d3 are the same within one module, they may vary between modules. However, due to the flexibility provided by the fingers 2516A and 2516B, both can contact the conductive pad on the printed circuit board.

[0214] Figure 26B Another embodiment is shown. Figure 26B In an embodiment, the flexible shield has a lossy material layer 2604 in addition to a body portion 2504, which may be formed of metal. The lossy material may be 0.1 mm to 2 mm thick, or may have other suitable dimensions, such as 0.1 mm to 1 mm thick.

[0215] Figure 27 A connector footprint 2700 is shown on a printed circuit board 2702 configured for use with a flexible shield according to another embodiment. Figure 27 The implementation method and Figure 19 1805A, 1805B. The embodiment differs in that a shadow via 2710 is incorporated into the module footprint 2720 adjacent to the vias for the differential signal conductors 1805A, 1805B. The shadow via 2710 can be electrically connected to the surface pad 1910. The shadow via can also be electrically connected to one or more internal reference layers (e.g., a ground plane) of the printed circuit board, such that the surface pad is also electrically connected to the ground plane through the shadow via. When the connector is installed, the conductive body 2504 can be pressed against the surface pad 1910 above the shadow via 2710, thereby creating a substantially direct conductive path from the reference tab, through the flexible shield, to the surface pad, to the shadow via, and then to the one or more reference layers of the printed circuit board.

[0216] Shadow vias 2710 can be located adjacent to signal vias 1805A and 1805B. In the example shown, a pair of shadow vias 2710 are located on a first line 2722 perpendicular to a second line 2724 that passes through signal vias 1805A and 1805B in the direction of column 1340. Second line 2724 can be located between the pair of shadow vias, such that the pair of shadow vias are equally spaced from signal vias 1805A and 1805B. In the illustrated embodiment, the shadow vias of each module footprint 2720 are aligned with the signal vias in a direction perpendicular to first line 2722. However, alignment of the shadow vias with the signal vias is not required. For example, in some embodiments, module footprint 2720 can have one shadow via on each side of line 2724, aligned with a line parallel to line 2722 but passing between signal vias, and in some embodiments, module footprint 2720 can be equidistant relative to the signal vias forming a differential pair. In some embodiments, for each module footprint 2720, at least one shadow via is positioned between ground vias 1815, for example, between a pair of reference vias located at opposite ends of a pair of signal vias.

[0217] Shadow vias 2722 may at least partially overlap the edge of hole 1912. In other embodiments, each module footprint 2720 may include more than one pair of shadow vias. Furthermore, the shadow vias may be implemented as one or more circular shadow vias or one or more slot-shaped shadow vias.

[0218] According to some embodiments, shadow via 2710 can be smaller than the vias used to receive the contact tails of the connector (e.g., smaller than signal vias 1805A, 1805B and / or reference via 1815). In embodiments where the shadow vias do not receive contact tails, the shadow vias can be filled with a conductive material during the manufacture of the printed circuit board. As a result, the unplated diameter of the shadow vias can be smaller than the unplated diameter of the vias receiving the contact tails. The diameter can be, for example, in the range of 8 mils to 12 mils, or at least 3 mils smaller than the unplated diameter of the signal or reference vias.

[0219] In some embodiments, the shadow vias can be positioned so that the length of the conductive path through the surface layer to the nearest shadow via coupling the conductive surface layer to the internal ground layer can be less than the thickness of the printed circuit board. In some embodiments, the conductive path through the surface layer can be 50%, 40%, 30%, 20%, or 10% less than the thickness of the circuit board. A short conductive path can be achieved by positioning the shadow via at or near a contact point, such as between the conductive body portion 2504 and the conductive surface pad 1910.

[0220] In some embodiments, the shadow vias can be positioned to provide a conductive path through the surface layer that is less than the average length of the conductive path of a signal between a connector, or other component mounted on the circuit board, and an inner layer of the circuit board to which the signal via is connected to a conductive trace. In some embodiments, the shadow vias can be positioned so that the conductive path through the surface layer can be 50%, 40%, 30%, 20%, or 10% less than the average length of the signal path.

[0221] In some embodiments, the shadow vias may be positioned to provide a conductive path through the surface layer of less than 5 mm. In some embodiments, the shadow vias may be positioned so that the conductive path through the surface layer may be less than 4 mm, 3 mm, 2 mm, or 1 mm.

[0222] The frequency range of interest may depend on the operating parameters of the system in which such a connector is used, but may generally have an upper limit between about 15 GHz and 50 GHz, such as 25 GHz, 30 GHz, or 40 GHz, although higher or lower frequencies may be of interest in some applications. Some connector designs may have a frequency range of interest that spans only a portion of the range, such as 1 GHz to 10 GHz, 3 GHz to 15 GHz, or 5 GHz to 35 GHz. At these high frequencies, the effects of unbalanced signal pairs and any discontinuities in the shield at the mounting interface may be more significant.

[0223] The operating frequency range of an interconnect system can be determined based on the range of frequencies that can pass through the interconnect with acceptable signal integrity. Signal integrity can be measured according to a number of criteria depending on the application for which the interconnect system is designed. Some of these criteria may relate to signal propagation along a single-ended signal path, a differential signal path, a hollow waveguide, or any other type of signal path. Two examples of such criteria are attenuation of the signal along the signal path or reflection of the signal from the signal path.

[0224] Other standards may relate to the interaction of multiple different signal paths. Such standards may include, for example, near-end crosstalk, which is defined as the portion of a signal injected on one signal path at one end of an interconnect system that can be measured at any other signal path on the same end of the interconnect system. Another such standard may be far-end crosstalk, which is defined as the portion of a signal injected on one signal path at one end of an interconnect system that can be measured at any other signal path on the other end of the interconnect system.

[0225] As a specific example, it is required that the signal path attenuation is no greater than 3dB power ratio, the reflection power ratio is no greater than -20dB, and the single signal path to signal path crosstalk contribution is no greater than -50dB. Since these characteristics are frequency dependent, the operating range of the interconnect system is limited to the range of frequencies that meet the specific standards.

[0226] Described herein are designs for electrical connectors that improve signal integrity for high frequency signals, such as frequencies in the GHz range, including up to about 25 GHz, up to about 40 GHz, up to about 50 GHz, up to about 60 GHz, or up to about 75 GHz, or higher, while maintaining high density, such as spacing between adjacent mating contacts of the order of 3 mm or less, including, for example, center-to-center spacing between adjacent contacts in a column of the order of 1 mm to 2.5 mm, or 2 mm to 2.5 mm. The spacing between mating contacts in each column may be similar, however, it is not required that all mating contacts in the connector have equal spacing.

[0227] The flexible shield can be used with any suitable connector configuration. In some embodiments, a connector with a broadside coupling configuration can be used to reduce skew. The broadside coupling configuration can be used for at least the middle portion of the signal conductor that is not straight, such as the middle portion that follows a 90-degree path in a right-angle connector.

[0228] While a broadside coupling configuration may be desirable for the middle portion of the conductive element, a full or primarily edge coupling configuration may be employed at the mating interface with another connector or at the attachment interface with a printed circuit board. Such a configuration may, for example, facilitate routing signal traces within the printed circuit board that are connected to vias that receive contact tails of the connector.

[0229] Thus, the conductive elements within the connector can have a transition region at either or both ends. In the transition region, the conductive elements can bend out of a plane parallel to the width dimension of the conductive elements. In some embodiments, each transition region can have a bend toward the transition region of another conductive element. In some embodiments, the conductive elements will each bend toward the plane of the other conductive element so that the ends of the transition region are aligned in the same plane parallel but between the planes of the individual conductive elements. To avoid contact in the transition region, the conductive elements can also bend away from each other in the transition region. Thus, the conductive elements in the transition region can be aligned edge to edge in a plane parallel but offset from the planes of the individual conductive elements. Such a configuration can provide balanced pairs over the frequency range of interest while providing routing channels within a printed circuit board that supports high density connectors or while providing mating contacts at a certain spacing that facilitates the manufacture of mating contact portions.

[0230] Although details of specific configurations of conductive elements, housings, and shielding members are described above, it should be understood that such details are provided for illustrative purposes only, as the concepts disclosed herein can be implemented in other ways. In this regard, the various connector designs described herein can be used in any suitable combination, as aspects of the present disclosure are not limited to the specific combinations shown in the accompanying drawings.

[0231] Thus, with these described embodiments, it will be appreciated that various modifications, alterations, and improvements may be readily made by those skilled in the art. Such modifications, alterations, and improvements are intended to fall within the spirit and scope of the present invention. Therefore, the foregoing description and accompanying drawings are intended to be exemplary only.

[0232] Various modifications may be made to the exemplary structures shown and described herein. For example, the flexible shield is described in conjunction with a connector attached to a printed circuit board. The flexible shield may be used in conjunction with any suitable component mounted on any suitable substrate. As a specific example of a possible modification, a flexible shield having a component slot may be used.

[0233] Manufacturing techniques may also vary. For example, an embodiment in which the daughter card connector 600 is formed by arranging multiple sheets onto a stiffener is described. It is possible that an equivalent structure can be formed by inserting multiple shields and signal receptacles into a molded housing.

[0234] As another example, a connector formed by modules is described, and each module includes a pair of signal conductors. It is not necessary for each module to just include a pair of signal conductors or that the number of signal pairs is the same in all modules in the connector. For example, 2 pairs or 3 pairs of modules can be formed. In addition, in some embodiments, a core module with two rows, three rows, four rows, five rows, six rows or some larger number of rows can be formed in a single-ended or differential pair configuration. Each connector or each thin slice in the embodiment of the connector lamination can include such a core module. For manufacturing, there are more rows than the rows included in the basic module, the core module can be coupled with extra modules (for example, each extra module has a smaller number of pairs, such as each module single pair).

[0235] In addition, although many aspects of the invention are shown and described with reference to a daughterboard connector having a right-angle configuration, it should be understood that the aspects of the present disclosure are not limited in this regard, as any inventive concept, whether alone or in combination with one or more other inventive concepts, can be used in other types of electrical connectors, such as backplane connectors, cable connectors, stacking connectors, mezzanine connectors, I / O connectors, chip sockets, etc.

[0236] In some embodiments, the contact tails are shown as press-fit "eye-of-the-needle" flexible sections designed to fit within vias in a printed circuit board. However, other configurations, such as surface mount components, spring-loaded contacts, solderable pins, etc., may also be used, as aspects of the present invention are not limited to the use of any particular mechanism for attaching the connector to a printed circuit board.

[0237] The present disclosure is not limited to the details of construction or arrangement of the components described above and / or set forth in the accompanying drawings. Various embodiments are provided for illustrative purposes only, and the concepts described herein can be practiced or implemented in other ways. In addition, the terms and terminology used herein are for descriptive purposes and should not be considered restrictive. The use of "including," "comprising," "having," "containing," or "involving" and variations thereof in this article is intended to encompass the items listed below (or their equivalents) and / or as supplementary items.

[0238] The present disclosure includes but is not limited to the following technical solutions.

[0239] 1. A flexible shield for an electrical connector comprising a plurality of contact tails for attachment to a printed circuit board, the flexible shield comprising:

[0240] A conductive body portion includes a plurality of openings sized and positioned to receive the contact tails of the electrical connector therethrough, wherein the conductive body portion provides a current flow path between a shield within the electrical connector and a ground structure of the printed circuit board.

[0241] 2. The flexible shielding member according to claim 1, comprising:

[0242] An insulating member, the insulating member comprising:

[0243] a plurality of openings sized and positioned to receive the contact tails of the electrical connector therethrough;

[0244] Part I; and

[0245] a plurality of islands extending from the first portion;

[0246] The conductive body is a flexible conductive member including a plurality of openings sized and shaped to conform to the plurality of islands.

[0247] 3. The flexible shield according to claim 2, wherein:

[0248] The plurality of islands have walls extending from the first portion; and

[0249] The wall has channels in the first portion extending from a plurality of second openings.

[0250] 4. The flexible shield according to claim 3, wherein:

[0251] The opening in the flexible conductive member is also sized and shaped to press against a protrusion inserted into the channel when the flexible conductive member is mounted to the insulating member.

[0252] 5. The flexible shield according to claim 2, wherein:

[0253] The flexible conductive member is filled with conductive particles at the load providing a lossy conductor.

[0254] 6. The flexible shield according to claim 2, wherein:

[0255] Each of the plurality of openings of the insulating member is a slot having a ratio between a longer dimension and a shorter dimension of at least 2:1.

[0256] 7. The flexible shield according to claim 6, wherein:

[0257] The plurality of openings of the insulating member are arranged in a repeating pattern of sub-patterns, each sub-pattern including a pair of slots aligned with a longer dimension disposed in a line and at least two additional slots.

[0258] 8. The flexible shield according to claim 7, wherein:

[0259] The slot of each of the plurality of sub-patterns extends through a corresponding island.

[0260] 9. The flexible shielding member according to claim 1, comprising:

[0261] A plurality of flexible fingers are attached to and extend from the conductive body portion.

[0262] 10. The flexible shield according to claim 9, wherein:

[0263] The plurality of flexible fingers include elongated beams, each beam having a proximal end integral with the conductive body portion and a free distal end.

[0264] 11. The flexible shield according to claim 9, wherein:

[0265] The flexible shield includes a second plurality of openings, and

[0266] Each of the plurality of flexible fingers extends from an edge of a corresponding opening of the second plurality of openings.

[0267] 12. The flexible shield according to claim 9, wherein:

[0268] The plurality of flexible fingers are resilient in a direction in which the contact tails of the connector are inserted into the plurality of openings of the conductive body portion of the flexible shield.

[0269] 13. The flexible shield according to claim 11, wherein:

[0270] The second plurality of openings are sized and positioned to receive reference protrusions of the electrical connector.

[0271] 14. The flexible shield according to claim 9, wherein:

[0272] The flexible shield is made of superelastic material.

[0273] 15. The flexible shield according to claim 9, wherein:

[0274] The plurality of openings may have a first size for a pair of differential signal contact tails and a second size for a reference contact tail.

[0275] 16. The flexible shield according to claim 15, wherein:

[0276] The plurality of openings are arranged in a repeating pattern of sub-patterns, each sub-pattern including a first sized opening and at least two second sized openings.

[0277] 17. An electrical connector, comprising:

[0278] a board mounting surface including a plurality of contact tails extending from the board mounting surface;

[0279] a plurality of internal shields; and

[0280] A flexible shield includes a conductive body portion including a plurality of openings sized and positioned to pass through the plurality of contact tails, wherein the conductive body is electrically connected to the plurality of internal shields.

[0281] 18. The electrical connector according to claim 17,

[0282] Wherein, the flexible shielding member includes

[0283] an insulating portion having a wall; and

[0284] The conductive body portion is a flexible conductive material between the walls;

[0285] At least a portion of the plurality of contact tails extends through the insulating portion.

[0286] 19. The electrical connector according to claim 18, wherein:

[0287] The wall includes a plurality of channels;

[0288] The electrical connector further includes conductive structures disposed in the plurality of channels; and

[0289] The flexible conductive material contacts the conductive structure.

[0290] 20. The electrical connector according to claim 19, wherein:

[0291] The conductive structure extends from the plurality of internal shields.

[0292] 21. The electrical connector according to claim 20, wherein:

[0293] The electrical connector includes a plurality of signal conductors arranged in pairs, each signal conductor including a respective contact tail of a first portion of the plurality of contact tails; and

[0294] The plurality of internal shields are arranged to separate adjacent pairs of the plurality of pairs.

[0295] 22. The electrical connector according to claim 21, wherein:

[0296] The plurality of inner shields include corresponding contact tails of a second portion of the plurality of contact tails.

[0297] 23. The electrical connector according to claim 22, wherein:

[0298] The conductive structure is a protrusion spaced apart from the contact tail of the second portion.

[0299] 24. The electrical connector according to claim 17,

[0300] Wherein, the flexible shield includes a plurality of flexible fingers attached to and extending from the conductive body portion.

[0301] 25. An electronic device comprising:

[0302] including printed circuit boards on the surface;

[0303] A connector mounted to the printed circuit board, the connector comprising:

[0304] a face parallel to the surface;

[0305] a plurality of conductive elements extending across the face;

[0306] a plurality of internal shields; and

[0307] A flexible shield provides a current flow path between the plurality of inner shields and a ground structure of the printed circuit board.

[0308] 26. The electronic device according to claim 25,

[0309] wherein the flexible shield comprises a conductive flexible member compressed between the connector and the printed circuit board, wherein the connector is configured such that the compressed flexible conductive member presses against the printed circuit board in a direction perpendicular to the surface of the printed circuit board and presses against a conductive element of the plurality of conductive elements in a direction parallel to the surface of the printed circuit board.

[0310] 27. The electronic device according to claim 26, wherein:

[0311] The printed circuit board has a ground pad on the surface; and

[0312] The conductive flexible member is pressed against the ground pad.

[0313] 28. The electronic device according to claim 27, wherein:

[0314] The printed circuit board further comprises:

[0315] a ground plane at an inner layer of the printed circuit board; and

[0316] A plurality of shaded vias connect the ground pad to the ground plane.

[0317] 29. The electrical connector according to claim 28, wherein:

[0318] the compressed flexible conductive member pressing against a conductive element of the plurality of conductive elements in a repeating pattern of a first position;

[0319] The shadow vias are located in a repeating pattern of second locations, each of the second locations having the same positioning relative to a corresponding first location.

[0320] 30. The electronic device according to claim 28, wherein:

[0321] A portion of the plurality of conductive elements includes a plurality of contact tails;

[0322] The connector is assembled from a plurality of modules;

[0323] Each module includes at least one signal conductor and a corresponding internal shield disposed on at least two sides of the signal conductor;

[0324] The at least one signal conductor and the corresponding inner shield each include a contact tail from the plurality of contact tails; and

[0325] The contact tails of each module are positioned in a pattern with the contact tails of the signal conductors at the center and the contact tails of the inner shield at the periphery.

[0326] 31. The electronic device according to claim 30, wherein:

[0327] the printed circuit board including a plurality of signal vias receiving the contact tails of the signal conductors and a plurality of ground vias receiving the contact tails of the inner shield; and

[0328] The plurality of shadow vias are arranged such that at least one shadow via is positioned between the ground vias that receive the contact tails of the inner shield of each of the plurality of modules.

[0329] 32. The electronic device according to claim 30, wherein:

[0330] Each module further includes at least one conductive structure extending from the corresponding inner shield and spaced apart from the contact tails of the inner shield; and

[0331] The plurality of shadow vias are arranged such that a length of a conductive path from a position where a portion of the conductive flexible member adjacent to the extended conductive structure presses against the ground pad, through the ground pad, to one of the plurality of shadow vias is less than a thickness of the printed circuit board.

[0332] 33. The electronic device according to claim 30, wherein:

[0333] Each module further includes at least one conductive structure extending from the corresponding inner shield and spaced apart from the contact tails of the inner shield; and

[0334] The plurality of shadow vias are arranged such that a length of a conductive path from a location where a portion of the conductive flexible member adjacent to the extended conductive structure presses against the ground pad, through the ground pad, to one of the plurality of shadow vias is less than an average length of a conductive path along a signal conductor to an internal conductive trace of the printed circuit board.

[0335] 34. The electronic device according to claim 25,

[0336] The flexible shield includes a conductive body portion substantially parallel to the surface and a plurality of flexible fingers attached to and extending from the conductive body portion.

[0337] 35. The electronic device according to claim 34, wherein:

[0338] The plurality of flexible fingers further include elongated beams, each beam having a proximal end integral with the conductive body portion and a free distal end.

[0339] 36. The electronic device according to claim 35, wherein:

[0340] The free distal end of the beam presses against the surface of the printed circuit board.

[0341] 37. The electronic device according to claim 34, wherein:

[0342] The printed circuit board has a ground pad on the surface; and

[0343] The flexible shield is pressed against the ground pad.

[0344] 38. The electronic device according to claim 37, wherein:

[0345] The printed circuit board further comprises:

[0346] a ground plane at an inner layer of the printed circuit board; and

[0347] A plurality of shaded vias connect the ground pad to the ground plane.

[0348] 39. The electrical connector according to claim 38, wherein:

[0349] the conductive body portion of the flexible shield including a plurality of openings in a repeating pattern at a first location, the plurality of openings being sized and positioned to receive contact tails of the plurality of conductive elements therethrough;

[0350] The shadow vias are located in a repeating pattern of second locations, wherein each of the second locations has the same positioning relative to a corresponding first location.

Claims

1. A flexible shield for an electrical connector comprising a plurality of contact tails for attachment to a printed circuit board, the flexible shield comprising: Matrix material; a plurality of first openings extending through the substrate material, the plurality of first openings being sized and positioned to receive a plurality of contact tails from the electrical connector therethrough; a conductive coating on the substrate material; as well as an insulating member comprising a plurality of second openings sized and positioned to receive the plurality of contact tails of the electrical connector therethrough, wherein: The conductive coating is configured to provide a current flow path between a shield within the electrical connector and a ground structure of the printed circuit board.

2. The flexible shield according to claim 1, wherein: The flexible shield has a hardness in the range of 35 to 90 Shore A scale.

3. The flexible shield according to claim 1 or 2, wherein: The conductive coating is configured to press against the conductive structure of the electrical connector in a direction parallel to the printed circuit board.

4. The flexible shield according to claim 1 or 2, wherein: The insulating member includes a first portion and a plurality of islands extending from the first portion, and The plurality of islands are disposed within the plurality of first openings.

5. The flexible shield according to claim 4, wherein: The plurality of islands have walls extending from the first portion; and The wall has channels extending from a plurality of third openings in the first portion.

6. The flexible shield of claim 5, wherein: The first plurality of openings are sized and shaped such that the conductive coating is pressed against the protrusions in the channel.

7. The flexible shield according to claim 5 or 6, wherein: The plurality of second openings of the insulating member are arranged in a repeating pattern of sub-patterns, each sub-pattern including a pair of slots aligned with a longer dimension arranged in a line and at least two additional slots extending through a respective island.

8. An electrical connector, comprising: a board mounting surface including a plurality of contact tails extending from the board mounting surface; multiple internal shields; a flexible shield extending to the board mounting surface, the flexible shield comprising a matrix material, a first plurality of openings extending through the matrix material, the first plurality of openings being sized and positioned to receive the plurality of contact tails therethrough, and a conductive coating on the matrix material, the conductive coating being electrically connected to the plurality of internal shields; as well as An insulating member includes a plurality of second openings sized and positioned to receive the plurality of contact tails of the electrical connector therethrough.

9. The electrical connector according to claim 8, wherein: The flexible shield has a hardness in the range of 35 to 90 Shore A scale.

10. The electrical connector according to claim 8 or 9, wherein: The insulating member includes a first portion and a plurality of islands extending from the first portion, the plurality of islands having walls extending from the first portion, and portions of the flexible shield are disposed between the walls.

11. The electrical connector according to claim 10, comprising: A conductive structure is disposed adjacent to the walls of the plurality of islands of the insulating member, wherein the conductive coating of the flexible shield contacts the conductive structure.

12. The electrical connector according to claim 11, wherein: The conductive structure extends from the plurality of internal shields.

13. The electrical connector according to claim 10, wherein: The insulating member includes a plurality of slots for the plurality of contact tails to extend therefrom.

14. The electrical connector according to claim 10, wherein: The plurality of islands of the insulating member are disposed within the plurality of first openings of the flexible shield.

15. An electrical connector, comprising: a board mounting surface including a plurality of contact tails extending from the board mounting surface; a plurality of signal conductors arranged in a plurality of pairs, the plurality of signal conductors including respective contact tails of a first portion of the plurality of contact tails; a plurality of internal shields arranged to separate adjacent pairs of the plurality of pairs, the plurality of internal shields including respective contact tails of a second portion of the plurality of contact tails; a flexible shield comprising a base material, a first plurality of openings extending through the base material, the first plurality of openings being sized and positioned to receive the plurality of contact tails therethrough, and a conductive coating on the base material, the conductive coating being electrically connected to the second portions of the plurality of contact tails; as well as An insulating member includes a plurality of second openings sized and positioned to receive the plurality of contact tails of the electrical connector therethrough.

16. The electrical connector according to claim 15, wherein: The flexible shield has a hardness in the range of 35 to 90 Shore A scale.

17. The electrical connector according to claim 15 or 16, wherein: The conductive coating is pressed against a second portion of the plurality of contact tails in a direction parallel to the board mounting surface.

18. The electrical connector according to claim 15 or 16, comprising: A projection extends from the plurality of inner shields and is spaced apart from the contact tails of the second portion.

19. The electrical connector according to claim 18, wherein: The conductive coating is configured to press against the protrusion in a direction parallel to the board mounting surface.

20. The electrical connector according to claim 15 or 16, wherein: The conductive coating is electrically isolated from a first portion of the plurality of contact tails.

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