Assembly for mounting an interface, electrical connector, electronic system and printed circuit board

Abstract

The present disclosure relates to assemblies for mounting interfaces, electrical connectors, electronic systems, and printed circuit boards. One embodiment relates to an assembly for a mounting interface of an electrical connector configured for a plurality of signal contact elements and a plurality of reference conductors within the connector to pass through the assembly to connect to a printed circuit board, the assembly comprising: an insulator comprising: a plurality of first openings sized and positioned for the plurality of signal contact elements from the electrical connector to pass through; and a plurality of second openings sized and positioned for the plurality of reference conductors from the electrical connector to pass through, wherein the plurality of first openings and the plurality of second openings are arranged in a repeating pattern of sub-patterns, and each sub-pattern comprises a pair of first openings and one or more second openings surrounding the pair of first openings.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201780073986.7 (PCT / US2017 / 057402), filed on October 19, 2017, entitled "Flexible Shielding for Ultra-High-Speed ​​High-Density Electrical Interconnection".

[0002] Cross-reference to related applications

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

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

[0005] Electrical connectors are used in many electronic systems. It is generally easier and more cost-effective to manufacture a system as individual electronic components, such as printed circuit boards (“PCBs”), that can be coupled together with electrical connectors. A known arrangement for coupling some PCBs is a PCB with a base plate. Other PCBs, known as “daughter boards” or “daughter cards”, can be connected via the base plate.

[0006] The known backplane is a printed circuit board (PCB), on which numerous connectors can 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 can also have connectors mounted on them. Connectors mounted on the daughter cards can be inserted into connectors mounted on the backplane. In this way, signals can be routed between daughter cards through the backplane. Daughter cards can be inserted into the backplane at right angles. Therefore, connectors used in these applications include right-angle bends and are commonly referred to as "right-angle connectors."

[0007] In other configurations, connectors can also be used for interconnecting printed circuit boards (PCBs) and other types of devices such as cables to PCBs. Sometimes, one or more smaller PCBs can be connected to another larger PCB. In such configurations, the larger PCB can be referred to as the "mother board" and the PCBs connected to the mother board can be referred to as daughter boards. Furthermore, PCBs of the same or similar size can sometimes be aligned in parallel. The connectors used in these applications are often referred to as "stack connectors" or "mezzanine connectors."

[0008] Regardless of the specific application, the adoption of electrical connector designs reflects trends in the electronics industry. Electronic systems are generally becoming smaller, faster, and more complex. Due to these changes, the number of circuits in a given area of ​​an electronic system, and the frequency at which these circuits operate, have increased significantly in recent years. Current systems transfer more data between printed circuit boards and require electrical connectors capable of processing significantly more data electrically at much higher speeds than connectors handled just a few years ago.

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

[0010] Examples of shielding can be seen in U.S. Patent Nos. 4,632,476 and 4,806,107, which illustrate connector designs using shielding between multiple rows of signal contacts. These patents describe connectors where the shielding extends parallel to the signal contacts through the daughterboard connector and the backplane connector. A cantilever beam is used to establish electrical contact between the shielding and the backplane connector. Similar arrangements are shown in U.S. Patent Nos. 5,433,617, 5,429,521, 5,429,520, and 5,433,618; however, the electrical connection between the backplane and the shielding is accomplished by spring-loaded contacts. The connector described in U.S. Patent No. 6,299,438 uses shielding with torsion beam contacts. Other shielding is shown in U.S. Pre-Grant Publication 2013-0109232.

[0011] Other connectors have a shielding plate only within the daughterboard connector. Examples of such connector designs can be seen in U.S. Patent Nos. 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 Nos. 5,484,310 and 7,985,097, which has a shielding plate only within the daughterboard connector.

[0012] Other techniques can be used to control connector performance. For example, differential signal transmission 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. Shielding between the conductive paths of a differential pair is not desirable, but shielding can be used between differential pairs. Electrical connectors can be designed for both differential and single-ended signals. Examples of differential electrical connectors are shown in U.S. Patent Nos. 6,293,827, 6,503,103, 6,776,659, 7,163,421, and 7,794,278.

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

[0014] Holes can be drilled on a printed circuit board to make electrical connections to conductive traces or ground / power planes. These holes, or "vias," are filled or plated with metal so that they are electrically connected to one or more conductive traces or planes they pass through.

[0015] To attach a connector to a printed circuit board, the connector's contact "tail" can be inserted into a via or attached to a conductive pad on the surface of the printed circuit board that connects to the via. Summary of the Invention

[0016] Implementations of high-speed, high-density interconnect systems are described. According to some implementations, ultra-high-speed performance can be achieved through a flexible shield that provides shielding around a contact tail extending from the connector housing. Alternatively or additionally, the flexible shield can provide current flow at desired locations between a shielding member within the connector and a grounding structure within the printed circuit board.

[0017] Therefore, some embodiments relate to flexible shielding for electrical connectors, which include multiple contact tails for attachment to a printed circuit board. The flexible shielding may include a conductive body portion comprising multiple openings sized and positioned such that the contact tails of the power connector pass through. The conductive body provides a current flow path between the shielding within the electrical connector and the grounding structure of the printed circuit board.

[0018] In some embodiments, the electrical connector may 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 may include a conductive body portion comprising a plurality of openings sized and positioned to allow the plurality of contact tails to pass through. The conductive body portion may 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 including a surface and a connector mounted to the printed circuit board. 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 printed circuit board.

[0020] The foregoing is a non-limiting overview of the invention, which is defined by the appended claims. Attached Figure Description

[0021] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in different drawings is indicated by the same reference numerals. For clarity, not every component may be labeled in every drawing. In the drawings:

[0022] Figure 1 This is an isometric view of an exemplary electrical interconnection system according to some implementation methods;

[0023] Figure 2 yes Figure 1 An isometric view of the cut-off portion of the base plate connector;

[0024] Figure 3 yes Figure 2 Isometric view of the pin assembly of the baseplate connector;

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

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

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

[0028] Figure 7 yes Figure 6 Isometric view of the wafer assembly of the daughter card connector;

[0029] Figure 8 yes Figure 7 An isometric view of the sheet module of the sheet assembly;

[0030] Figure 9 yes Figure 7 An isometric view of a portion of the insulating housing of the sheet assembly;

[0031] Figure 10 yes Figure 7A partially decomposed isometric view of the sheet module of the sheet assembly;

[0032] Figure 11 yes Figure 7 A partially decomposed isometric view of a portion of the sheet module of the sheet assembly;

[0033] Figure 12 yes Figure 7 A partially decomposed isometric view of a portion of the sheet module of the sheet assembly;

[0034] Figure 13 yes Figure 7 An isometric view of a pair of conductive elements in a sheet module of a sheet 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 cut Figure 13 An end view of a pair of conductive elements;

[0037] Figure 15 This is an isometric view of two sheet modules of a connector according to some embodiments and a partially exploded view of the flexible shield.

[0038] Figure 16 This shows the attachment to two thin-film modules. Figure 15 The insulating portion of the flexible shielding is shown, and an isometric view of the flexible conductive member is also shown.

[0039] Figure 17A It shows the installation configuration with Figure 16 Isometric view of the insulating portion of the flexible shielding component adjacent to the flexible conductive component.

[0040] Figure 17B This is a plan view of the flexible shielding component facing the circuit board.

[0041] Figure 18 Connector footprints in a printed circuit board with wide wiring channels according to some embodiments are depicted.

[0042] Figure 19 Connector footprints in a printed circuit board with a surface ground pad are depicted according to some embodiments.

[0043] Figure 20 Connector footprints in a printed circuit board with surface ground pads and shadow vias according to some embodiments are depicted.

[0044] Figure 21AConnector footprints in a surface-grounded printed circuit board according to some embodiments are depicted. Dashed lines indicate the locations of flexible conductive components;

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

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

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

[0048] Figure 23 It corresponds to Figure 17A Cross-sectional view of plane 23 marked in the middle;

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

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

[0051] Figure 25B yes Figure 25A Enlarged plan view of the area marked 25B;

[0052] Figure 26A It is based on some implementation methods corresponding to Figure 25B The cross-sectional view of cut line 26 in the figure shows the flexible shield in an uncompressed state;

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

[0054] Figure 27 Connector footprints in a printed circuit board with surface ground pads and shadow vias according to some embodiments are depicted. Detailed Implementation

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

[0056] Furthermore, the flexible shielding, combined with the connector and the printed circuit board (PCB) mounting the connector, can be configured to provide a current flow path between the shielding within the connector and the grounding structure within the PCB. These paths can extend parallel to the current path in the signal conductors that carries the current from the connector to the PCB. The inventors have found that this configuration provides a desirable increase in signal integrity, particularly for high-frequency signals, even over very small distances, such as 2 mm or less.

[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 surface pads on the printed circuit board via a flexible shield. The surface pads can then be connected to the inner ground layer of the printed circuit board via 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 signal conductors that also extend from the connector. Therefore, a suitably positioned current flow path can exist: through the shield inside the connector, into the protrusions, through the flexible shield, into the surface pads on the printed circuit board, and through the shadow vias to the inner ground layer of the printed circuit board.

[0058] The flexibility of the shield can facilitate electrical connections through it, allowing the shield to be compressed when the connector is mounted to the printed circuit board. This flexibility enables the shield to occupy the space between the connector and the printed circuit board, regardless of potential variations in separation due to manufacturing tolerances.

[0059] Furthermore, the shielding element can be made of a material that provides force in an orthogonal direction upon compression, for example, by expanding and applying a force in a second direction to any adjacent structure in response to a force on the shielding element in the first direction, the second direction being orthogonal to the first direction. Suitable flexible conductive materials for manufacturing at least a portion of the shielding element include elastomers filled with conductive particles.

[0060] When the shield is compressed, applying force in at least two orthogonal directions can press the shield together, thus enabling electrical connection with conductive pads on the surface of the printed circuit board and conductive elements extending from the connector. These extensions can have surfaces orthogonal to the surface of the printed circuit board. Contacting the extended conductive elements on the surface provides a wide area for contact thereon, improving the connector's performance related to contacting the shield along the edges of the extended conductive elements.

[0061] To provide mechanical support for the flexible conductive material and other structures, the flexible shield may include an insulating member. The insulating member may have a first portion, which may be generally planar and shaped on one surface, supporting a mounting surface of the connector. Opposite surfaces of the insulating member may have multiple raised portions, forming islands extending from the first portion. These islands may have walls, and the flexible conductive material may occupy the space between the walls. Extended conductive elements may be disposed adjacent to the walls such that when the flexible conductive material is compressed, it extends outward toward the walls, pressing against the extended conductive elements. The extended conductive elements may be supported by and mechanically supported by the walls.

[0062] An island can provide an insulating region for shielding, through which signal conductors can be grounded without contact with a flexible conductive material. In some embodiments, the island can be formed of a material having a dielectric constant that establishes the necessary impedance for the signal conductors in the connector's mounting interface. In some embodiments, the relative permittivity can be 3.0 or higher. In some embodiments, the relative permittivity can be higher, for example, 3.4 or higher. In some embodiments, at least the island's relative permittivity 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. This relative permittivity can be achieved by selecting adhesive materials and fillers. Known materials can be selected to provide, for example, a relative permittivity up to 4.5. In some embodiments, the relative permittivity can be up to 4.4, up to 4.3, up to 4.2, up to 4.1, or up to 4.0. Relative permittivity within these ranges can result in the island having a higher dielectric constant than the connector's insulating housing. In some embodiments, the island may have a relative permittivity 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 permittivity 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 can be created between the shield within the connector and the grounding structure on the printed circuit board by contact tails extending from the internal connector shield that engages with the flexible shield and attach to conductive pads on the printed circuit board. The flexible shield may include a conductive body and a plurality of flexible fingers attached to and extending from the conductive body. Such a flexible shield may be formed from a sheet of conductive material.

[0064] According to some embodiments, the 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 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 be connected to the inner ground layer of the printed circuit board via vias that receive the contact tails of connectors, plus shadow vias.

[0065] Flexible shielding can be made of a material that has the desired conductivity for current paths. The material can also be appropriately elastic, such that fingers cut from the material generate sufficient force to ensure reliable electrical connection to surface pads on a printed circuit board and / or conductive structures extending from a connector. Suitable flexible conductive materials for manufacturing at least a portion of the flexible shielding include metals, metal alloys, hyperelastics, and shape memory materials. Hyperelastic and shape memory materials are described in co-pending U.S. Prelicensure Publication 2016-0308296, the entire contents of which are incorporated herein by reference.

[0066] Electrical connections via flexible shielding can be facilitated by the flexibility of the shielding, allowing the shielding to be compressed when the connector is mounted to the printed circuit board. This flexibility enables the shielding to generate a force against the printed circuit board, regardless of possible variations in spacing due to manufacturing tolerances. In embodiments where flexibility is achieved through the deflection of fingers cut from a metal sheet, the fingers, in their uncompressed state, can bend beyond the plane of the metal sheet by an amount equal to the tolerance required to position the connector's mounting surface against the upper surface of the printed circuit board.

[0067] Flexibility of the shield can be provided by resilient fingers that can deform to accommodate manufacturing variations in the separation between the circuit board and the connector. The fingers can extend from a metal strip located between the connector and the printed circuit board. However, in some embodiments, the fingers can extend from the internal shield or the grounding structure of the connector, passing through and electrically contacting the 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 may be adjacent to the contact tail of a signal conductor extending from the connector. In some embodiments, the proximal end of the finger may be attached to the body of the shield. The shield may be configured to engage a ground contact tail, protrusion, or other conductive structure extending from the shield within the connector. Therefore, a suitable current flow path can exist that passes through the shield inside the connector, through the flexible shield, into pads on the surface of the printed circuit board, and through the shadow via to the inner ground layer of the printed circuit board.

[0069] Figure 1 An electrical interconnect system in the form of one that can be used in an electronic system is illustrated. In this example, the electrical interconnect system includes right-angle connectors and can be used, for example, to electrically connect a daughter card to a base plate. The figures show two mating connectors. In this example, connector 200 is designed to attach to the base plate, while connector 600 is designed to attach to the daughter card. Figure 1 As can be seen, the daughter card connector 600 includes contact tails 610 designed to attach to a daughter card (not shown). The baseplate connector 200 includes contact tails 210 designed to attach to a baseplate (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 electrically connect to a signal-carrying conductive structure within the printed circuit board or to a reference potential. In the example shown, the contact tails press-fit "eyelet" contacts, which are designed to press into vias in the printed circuit board. However, other forms of contact tails may be used.

[0070] Each connector in the connector assembly also has a mating interface at which it can mate with or separate from another connector. The daughter card connector 600 includes a mating interface 620. The base plate connector 200 includes a mating interface 220. Although in Figure 1 The view shown is not fully visible, but the mating contacts 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. The intermediate portion may be retained within the connector housing, at least a portion of which may be dielectric to provide electrical isolation between the conductive elements. Additionally, the connector housing may include conductive or dissipative portions, which in some embodiments may provide conductive or partially conductive paths between some of the conductive elements. In some embodiments, the conductive portions may provide shielding. Dissipative portions may also provide shielding in certain circumstances, and / or provide desired electrical performance within the connector.

[0072] In various embodiments, the dielectric component may 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 this disclosure is not limited in this respect.

[0073] All of the above-described materials are suitable for use as adhesive materials in the manufacture of connectors. According to some embodiments, one or more fillers may be included in some or all of the adhesive materials. As a non-limiting example, thermoplastic PPS with a volumetric fill of 30% glass fiber can be used to form the entire connector housing or the dielectric portion of the housing.

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

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

[0076] Other components that may form part of the connector housing can provide the mechanical integrity of the daughter card connector 600 and / or retain the tab in the desired position. For example, the front housing portion 640 ( Figure 6 The connector housing can accommodate portions of the sheet forming a 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 implementations, each sheet may hold a row of conductive elements forming a signal conductor. These signal conductors may be shaped and spaced to form single-ended signal conductors. However, in Figure 1In the illustrated embodiment, signal conductors are shaped in pairs and spaced apart to provide differential signal conductors. Each column may include or be defined by a conductive element serving as a ground conductor. It should be understood that the ground conductor does not need to be connected to a ground, but is shaped to carry a reference potential, which may include a ground voltage, a DC voltage, or other suitable reference potential. The “ground” or “reference” conductor may have a different shape than the signal conductors, which are configured to provide suitable signal transmission performance for high-frequency signals.

[0078] Conductive elements can be made of metal or any other conductive material and provide 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. Conductive elements can be formed from such materials by any suitable method, including stamping and / or forming.

[0079] The spacing between conductors in adjacent columns can be within a range that provides the desired density and 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 in each column can be spaced 2.4 mm apart. However, higher density can be achieved by placing the conductors close together. In other embodiments, for example, smaller dimensions can be used to provide higher density, such as a thickness between 0.2 mm and 0.4 mm, or a spacing between conductors in each column or within a column of 0.7 mm to 1.85 mm. Furthermore, each column can include four pairs of signal conductors, such that… Figure 1 The interconnect system shown 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, closer spacing between pairs within a column, and / or smaller spacing between columns.

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

[0081] Assembling wafers from modules can help reduce the “offset” of signal pairs at higher frequencies, such as between approximately 25 GHz and 40 GHz or higher. In this context, offset refers to the difference in electrical propagation time between a pair of signals operating as differential signals. A module structure designed to reduce offset 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 of modules, each module carrying a signal pair. Modules can be individually shielded, for example by attaching shielding members to the modules, and / or inserting the modules into organizers or other structures that can provide electrical shielding between multiple pairs and / or around the conductive elements carrying the signals.

[0083] In some implementations, signal conductor pairs within each module can be wide-side coupled along the main portion of their length. Wide-side coupling ensures that the pair of signal conductors have the same physical length. To facilitate the routing of signal traces within the connector footprints of a printed circuit board to which connectors are attached and / or the construction of the mating interface of the connectors, the signal conductors can be aligned edge-to-edge in one or both of these regions. Therefore, the signal conductors can include transition regions where the coupling changes from edge-to-edge to wide-side or vice versa. As described below, these transition regions can be designed to prevent mode transitions or suppress undesired 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 implementations, different modules can be formed for each row position of a pair assembled into a right-angle connector. These modules can be manufactured together to construct a connector 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 in the shortest row (sometimes referred to as row ab) of the connector. Separate modules can be formed for the conductive elements in the second longest row (sometimes referred to as row cd). The interior of the module in row cd can be designed to conform to the exterior of the module in row ab.

[0085] This pattern can be repeated for any number of pairs. Each module can be shaped for use with modules carrying multiple pairs of conductor elements in shorter and / or longer rows. To manufacture connectors of any suitable size, connector manufacturers can assemble multiple modules into a sheet to provide the desired number of pairs within the sheet. In this way, connector manufacturers can promote widely used connector sizes such as 2 pairs across their connector families. When customer requirements change, connector manufacturers can acquire tools for each additional pair or for modules containing multiple pairs or groups of pairs to produce larger-sized connectors. Tools used to produce modules for smaller connectors can be used to produce modules for shorter rows, or even shorter rows, of larger connectors. Figure 8 This modular connector is shown in the image.

[0086] Figure 2 China provides Figure 1Further details of the interconnect system's construction are shown, illustrating a partially cut-off backplane connector 200. Figure 2 In the embodiment shown, the front wall of the housing 222 is cut off to expose the interior of the mating interface 220.

[0087] In the illustrated embodiment, the baseplate connector 200 also has a modular construction. Multiple 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, a four-row by eight-column pin module 300 is shown. With each pin module having two signal conductors, the four rows of pin modules 230A, 230B, 230C, and 230D produce a total of four pairs or eight signal conductors in each column. However, it should be understood that the number of signal conductors per row or column is not a limitation of the invention. The housing 222 may include a larger or smaller number of rows of pin modules. Similarly, the housing 222 may include a larger or smaller number of columns. Alternatively or additionally, the housing 222 may be considered as a module of a backplane connector, and multiple such modules may be aligned side-to-side to extend the length of the backplane connector.

[0089] exist Figure 2 In the illustrated embodiment, each pin module in the pin module 300 includes a conductive element that serves as a signal conductor. These signal conductors are held within an insulating member, which may serve as part of the housing of the baseplate 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, for example, by the use of a lossy material.

[0090] In some embodiments, housing 222 may include both conductive and lossy portions. For example, the shroud including wall 226 and base plate 228 may be extruded from powder metal or formed from conductive material in any other suitable manner. Pin module 300 may be inserted into an opening within base plate 228.

[0091] Loss-prone or conductive components can be positioned adjacent to rows 230A, 230B, 230C, and 230D of the pin module 300. Figure 2In some embodiments, spacers 224A, 224B, and 224C are shown between pin modules in adjacent rows. Spacers 224A, 224B, and 224C may be conductive or dissipative and may be formed as identical components or from the same members forming walls 226 and base plate 228. Alternatively, spacers 224A, 224B, and 224C may be inserted into housing 222 after walls 226 and base plate 228 are formed. In embodiments where spacers 224A, 224B, and 224C are formed from walls 226 and base plate 228 and subsequently inserted into housing 222, spacers 224A, 224B, and 224C may be formed from a different material than walls 226 and / or base plate 228. For example, in some embodiments, walls 226 and base plate 228 may be conductive while spacers 224A, 224B, and 224C may be dissipative or partially dissipative and partially conductive.

[0092] In some embodiments, additional loss-generating or conductive components may extend perpendicularly to the mating interface 220 from the base plate 228. Component 240 is shown adjacent to the outermost rows 230A and 230D. Compared to the separators 224A, 224B, and 224C extending across the mating interface 220, separator components 240, with a width approximately the same as the width of a column, are positioned adjacent to rows 230A and 230D in a row. The daughter card connector 600 may include slots in its mating interface 620 for receiving separators 224A, 224B, and 224C. The daughter card connector 600 may include openings similarly receiving components 240. Component 240 may have similar electrical effects to separators 224A, 224B, and 224C, all of which can suppress resonance, crosstalk, or other undesirable electrical effects. Because component 240 fits into an opening in daughter card connector 600 that is smaller than that of separators 224A, 224B, and 224C, component 240 can achieve greater mechanical integrity of the housing portion of daughter card connector 600 on the side receiving component 240.

[0093] Figure 3 The pin module 300 is shown in more detail. In this embodiment, each pin module includes a pair of conductive elements serving as signal conductors 314A and 314B. Each signal conductor 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 intermediate portion of the signal conductor connecting the contact tail to the mating contact portion passes through the pin module 300.

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

[0095] Figure 4 An exploded view of the pin module 300 is shown. The middle portions of signal conductors 314A and 314B are held within an insulating member 410, which can form part of the housing of the baseplate connector 200. The insulating member 410 can be molded around the signal conductors 314A and 314B. Figure 4 In the exploded view, the surface 412 against which the reference conductor 320B is pressed is visible. Similarly, it can also be seen in Figure 4 The reference conductor 320A's surface 428 is seen in the image, and surface 428 presses against member 410. Figure 4 The surface that is not visible in the middle.

[0096] As can be seen, surface 428 is generally intact. Attachment components such as protrusions 432 may be formed in surface 428. Such protrusions can engage openings in the insulating member 410. Figure 4 (Not visible in the view shown) to hold reference conductor 320A to insulating member 410. Similar protrusions (not numbered) may be formed in reference conductor 320B. As shown, these protrusions, serving as attachment mechanisms, are centered between signal conductors 314A and 314B, where the radiation or influence on the conductive elements is relatively low. Additionally, protrusions such as 436 may be formed in reference conductors 320A and 320B. Protrusion 436 may engage insulating member 410 to hold pin module 300 in an opening in base plate 228.

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

[0098] Reference conductors 320A and 320B can be held to the pin module 300 in any suitable manner. As noted above, protrusions 432 can engage openings 434 in the housing portion. Additionally or alternatively, strips or other components can be used to hold other portions of the reference conductors. As shown, each reference conductor includes strips 430A and 430B. Strip 430A includes protrusions while strip 430B includes openings adapted to receive these protrusions. Here, reference conductors 320A and 320B have the same shape and can be made with the same tools, but are mounted on opposing surfaces of the pin module 300. Thus, aligning a protrusion 430A of one reference conductor with a protrusion 430B of the opposing reference conductor causes protrusions 430A and 430B to interlock and hold the reference conductor in place. These protrusions can engage in openings 448 in the insulating member, which can further facilitate holding the reference conductors relative to signal conductors 314A and 314B in the pin module 300 in the desired orientation.

[0099] Figure 4 The tapered surface 450 of the insulating member 410 is further shown. In this embodiment, surface 450 is tapered relative to the axis of the signal conductor pair formed by signal conductors 314A and 314B. Surface 450 is tapered, meaning that surface 450 is closer to the distal end of the mating contact and further away from the axis of the signal conductor pair. In the illustrated embodiment, the pin module 300 is symmetrical with respect 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 a mating connector may be tapered. Therefore, although... Figure 4As not shown, the surface of the insulating portion of the daughter card connector 600 adjacent to the tapered surface 450 can taper in a complementary manner, such that when the connector is in the designed mating position, the surface of the mating connector matches the surface of the connector.

[0101] The tapered surface in the mating interface can prevent abrupt changes in impedance due to connector separation. Therefore, other surfaces designed to be adjacent to the mating connector can also be similarly tapered. Figure 4 A tapered surface 452 is shown. As shown, the tapered surface 452 is located between signal conductors 314A and 314B. Surfaces 450 and 452 fit together to form a tapered portion provided on the insulating portions on both sides of the signal conductors.

[0102] Figure 5 Further details of the pin module 300 are shown. Here, the signal conductors separated from the pin module are shown. Figure 5 The diagram shows a signal conductor before it is molded by overlaying with an insulating portion or otherwise incorporated into the pin module 300. However, in some embodiments, the signal conductor may be carried by a carrier tape or... Figure 5 Other suitable support mechanisms, not shown, are held together.

[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 mating contacts shaped like pins. Each signal conductor also has intermediate portions 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 used in each signal conductor. Transition regions, as shown, may be included to provide a gradual transition between different width regions. Contact tails 516A or 516B may also be included.

[0104] In the illustrated embodiment, the intermediate portions 512A, 512B, 514A, and 514B may be flat, having wide edges and narrower edges. In the illustrated embodiment, this pair of signal conductors is aligned edge-to-edge and thus configured for edge coupling. In other embodiments, some or all of the signal conductor pairs may alternatively be wide-edge 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 by any other suitable method. Such a shape can be formed, for example, by stamping a metal sheet including a central portion. A portion of the material can be rolled into a tube to provide the mating contact portion. Alternatively or additionally, the wire or other cylindrical element can be flattened to form the central portion, thus leaving the cylindrical mating contact portion. One or more openings (not numbered) can be formed in the signal conductor. Such openings ensure a secure engagement between the signal conductor and the insulating member 410.

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

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

[0108] The mating contact portion of the sheet 700A is held within the front housing portion 640. The front housing portion can be made of any suitable material, which can be insulating, dissipative, or conductive, or may include any suitable combination of said materials. For example, the front housing portion can be molded from a filled dissipative material using materials and techniques similar to those described above for housing wall 226, or it can be formed from a conductive material. As shown, the sheet is composed of modules 810A, 810B, 810C, and 810D (… Figure 8 The modules are assembled such that each module has a pair of signal conductors surrounded by a reference conductor. In the illustrated embodiment, the front housing portion 640 has multiple passages, each 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 two or more signal conductors.

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

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

[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 and then fastened together to hold modules 810A…810D therein. Components 900A and 900B can be held together in any suitable manner, such as by forming an interference fit or a snap-fit ​​attachment member. 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 component or may include a lossy or conductive component. 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, for example, via an insert molding operation. In such an embodiment, it is not necessary to form components 900A and 900B separately. Instead, a housing portion holding modules 810A…810D can be formed in one operation.

[0113] Figure 8 Modules 810A…810D without components 900A and 900B are shown. The reference conductor is visible in this view. Signal conductor ( Figure 8 (Not visible in the middle) is enclosed within a 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 conductor is positioned edge-to-edge. Within the middle region 830, the signal conductor is positioned for wide-edge coupling. Transition regions 822 and 842 are configured to transition between edge coupling orientation and wide-edge coupling orientation.

[0114] The transition regions 822 and 842 in the reference conductor may correspond to the transition regions in the signal conductor, as described below. In the illustrated embodiment, the reference conductor forms a closure around the signal conductor. In some embodiments, the transition regions in the reference conductor may maintain a generally consistent spacing between the signal conductor and the reference conductor along the length of the signal conductor. Therefore, the closure formed by the reference conductor may have different widths in different regions.

[0115] The reference conductor provides shielding coverage along the length of the signal conductor. As shown, coverage is provided for virtually the entire length of the signal conductor due to the coverage in the mating contacts and the middle portion. The contact tails are shown exposed so that they can contact the printed circuit board. However, in use, these mating contacts will be adjacent to the grounding structure within the printed circuit board, so that the exposed mating contacts, as shown in Figure 8, do not impair the shielding coverage along virtually the entire length of the signal conductor. In some embodiments, the mating contacts may also be exposed for mating to another connector. Thus, in some embodiments, shielding coverage may be provided for more than 80%, 85%, 90%, or 95% of the middle portion of the signal conductor. Similarly, shielding coverage may also be provided in the transition region, so that shielding coverage may be provided for more than 80%, 85%, 90%, or 95% of the mating length of the middle portion and the transition region of the signal conductor. In some embodiments, the mating contact area and some or all of the mating contacts may also be shielded, so that shielding coverage may be provided for more than 80%, 85%, 90%, or 95% of the length of the signal conductor in various embodiments.

[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 dimensions 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 certain 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 waveguide is wider in the column direction than in the transverse direction, thus providing a waveguide aspect ratio of at least 2:1 in these regions, and in some embodiments, at least on the order of 3:1. Conversely, in the middle section 830, the signal conductor is oriented with a width dimension covering the signal conductor along the column direction, resulting in a waveguide aspect ratio that is less than 2:1, and in some embodiments, less than on the order of 1.5:1 or 1:1.

[0118] Thanks to this smaller aspect ratio, the maximum size of the waveguide in the intermediate section 830 will be smaller than the minimum size of the waveguides in regions 830 and 840. Since the lowest frequency of waveguide propagation is inversely proportional to the length of its shortest dimension, the lowest frequency mode that can be excited in the intermediate section 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 somewhere in between the frequency modes excited in the contact tail region 820 and the mating contact region 840. Because the transition from edge coupling to wide-side coupling has a potential for exciting the desired waveguide modes, signal integrity can be improved at frequencies higher than or at least as high as possible within the connector's expected operating range.

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

[0120] Although the reference conductors can substantially enclose each pair of signal conductors, the enclosure is not required to be without openings. Therefore, in embodiments shaped to provide a rectangular shield, the reference conductor in the middle can be aligned with at least a portion of all four sides of the signal conductors. The reference conductors can be combined to, for example, provide 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 and together form the enclosure.

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

[0122] In some implementations, the shielding coverage can be different in different regions. In transition regions, the shielding coverage can be larger than in intermediate regions. In some implementations, due to direct contact or even overlap in the reference conductors in the transition regions, the shielding coverage can have an angular range greater than 355 degrees, or even 360 degrees in some implementations, even while providing smaller shielding coverage in the transition regions.

[0123] The inventors have recognized and understood that, in a sense, signal pairs in a completely enclosed intermediate region of a reference conductor can have undesirable effects on signal integrity, particularly when used in conjunction with the transition between edge coupling and wide-side coupling within a module. A waveguide can be formed around the reference module surrounding the signal pair. Signals on the pair of signal conductors, and especially in the transition region between edge coupling and wide-side coupling, can cause energy excitation of differential propagation modes between the edges, which 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 excitationd.

[0124] Some techniques used to increase frequency can excite undesirable modes. In the illustrated embodiment, the reference conductor can be shaped to have openings 832. These openings can be within the narrow walls of the closure. However, in embodiments with wide walls, the openings can be within the wide walls. In the illustrated embodiment, openings 832 extend parallel to the middle portion of the signal conductors and are located between a pair of signal conductors. These slots reduce the angular range of the shielding, such that the angular range of the shielding near the middle portion of the signal conductors coupled via the wide side can be less than 360 degrees. The angular range can, for example, be in the range of 355 degrees or less. In embodiments where components 900A and 900B are formed by overlaying molded lossy material on the module, the lossy material can be allowed to fill openings 932, whether extending into or not into the waveguide interior, which can suppress the propagation of undesirable signal propagation modes that can reduce signal integrity.

[0125] exist Figure 8 In the embodiment shown, the opening 832 is slot-shaped, effectively dividing the shielding in the intermediate region 830 into two parts. Due to the presence of... Figure 8 The effect shown is essentially that of a reference conductor surrounding the signal conductor; in a structure used as a waveguide, the lowest frequency that can be excited is inversely proportional to the side dimensions. In some implementations, the lowest frequency waveguide mode that can be excited is a TEM mode. Effectively shortening the side by incorporating a slotted opening 832 increases the frequency of the TEM mode that can be excited. A higher resonant frequency can mean less energy coupling into undesirable propagation within the waveguide formed by the reference conductor in the connector's operating frequency range, thus improving signal integrity.

[0126] In region 830, a pair of signal conductors are wide-side coupled, and an opening 832, with or without lossy material, can suppress common TEM propagation modes. While not limited by any particular operating theory, the inventors reason that the opening 832, which transitions from edge coupling to wide-side coupling, helps to provide a balanced connector suitable for high-frequency operation.

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

[0128] Components 900A and 900B may be molded from or comprise lossy materials. These and other lossy structures may use any suitable lossy material. Materials that are conductive but have some loss, or materials 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 may be formed from lossy dielectric materials and / or weakly conductive materials and / or lossy magnetic materials. Magneticly lossy materials may be formed, for example, from materials conventionally considered ferromagnetic materials, such as those with a magnetic loss factor greater than about 0.05 within the frequency range of interest. The “magnetic loss factor” is the ratio of the imaginary part to the real part of the material’s complex electromagnetic constant. Actual magnetically lossy materials, or mixtures containing magnetically lossy materials, may also exhibit a useful amount of dielectric or conductive loss effect within a portion of the frequency range of interest. Electrically lossy materials may be formed from materials conventionally considered dielectric materials, such as those with an electrical loss factor greater than about 0.05 within the frequency range of interest. The “electrical loss factor” is the ratio of the imaginary part to the real part of the material’s complex dielectric constant. The electrical loss material can also be formed from a material that is generally considered a conductor but is a relatively poor conductor in the frequency range of interest, the material comprising well-dispersed conductive particles or regions that do not provide high conductivity or are otherwise prepared to have a relatively weak bulk conductivity compared to good conductors such as copper in the frequency range of interest.

[0129] Electrically dissipative materials typically have a bulk conductivity of about 1 siemen / m to about 10,000 siemens / m, and preferably about 1 siemens / m to about 5,000 siemens / m. In some embodiments, materials with a bulk conductivity between about 10 siemens / m and about 200 siemens / m can be used. As a specific example, a material with a conductivity of about 50 siemens / m 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 the appropriate conductivity that provides appropriately low crosstalk and appropriately low signal path attenuation or insertion loss.

[0130] The electrical loss material can be a partially conductive material, such as a material with a surface resistivity between 1 Ω / square and 100,000 Ω / square. In some embodiments, the electrical loss 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 about 20 Ω / square and 80 Ω / square.

[0131] In some embodiments, the loss-inducing material is formed by adding a filler containing conductive particles to an adhesive. In such embodiments, the loss-inducing component can be formed by molding or otherwise shaping the adhesive with the filler into a desired shape. Examples of conductive particles that can be used as fillers to form the loss-inducing material include carbon or graphite formed as fibers, flakes, nanoparticles, or other types of particles. Metals or other particles in powder, flake, or fiber form can also be used to provide suitable loss-inducing properties. Alternatively, combinations of fillers can be used. For example, metals plated with carbon particles can be used. Silver and nickel are suitable metals for fiber plating. The 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 additionally used to position the filler material. In some embodiments, the adhesive can be a thermoplastic material, which is traditionally used as part of the manufacture of electrical connectors to facilitate the molding of the loss-inducing material into a desired shape and position. Examples of such materials include liquid crystal polymers (LCPs) and nylon. However, many alternative forms of adhesive materials can be used. Curable materials such as epoxy resins can be used as adhesives. Alternatively, materials such as thermosetting resins or adhesives can be used.

[0132] Furthermore, while the aforementioned adhesive materials can be used to generate electrical loss materials by forming an adhesive around conductive particle fillers, the present invention is not limited thereto. For example, conductive particles can be impregnated into or coated onto a formed matrix material, such as by applying a conductive coating to a plastic or metal component. As used herein, the term "adhesive" includes encapsulating fillers, matrix impregnated with fillers, or otherwise used as a filler retainer.

[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 using metal fibers, the fibers may be present in a volume percentage of about 3% to 40%. The amount of filler affects the electrical conductivity of the material.

[0134] Filler materials can be purchased on the market, such as those produced by Celanese under its trademark. The material sold may be filled with carbon fiber or stainless steel wire. Alternatively, a pre-finished adhesive filled with dissipative conductive carbon, such as the lossy material sold by Techfilm of Billerica, Massachusetts, may be used. This pre-finished material may include an epoxy adhesive filled with carbon fiber and / or other carbon particles. The adhesive surrounds the carbon particles, which may serve as a reinforcing material for the pre-finished material. Such a pre-finished material can be inserted into a connector sheet to form all or part of a housing. In some embodiments, the pre-finished material may be adhered by an adhesive in the pre-finished material, which may be cured during heat treatment. In some embodiments, the adhesive may be in the form of a separate conductive or non-conductive adhesive layer. In some embodiments, the adhesive in the pre-finished material may be used alternatively or additionally to secure one or more conductive elements, such as foils, to the lossy material.

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

[0136] In some embodiments, the loss element can be manufactured by stamping a pre-form or a sheet of loss material. For example, an insert can be formed by stamping a pre-form as described above with a suitable opening pattern. However, other materials can be used as an alternative to or supplement to such a pre-form. For example, a sheet of ferromagnetic material can be used.

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

[0138] Figure 10 Further details of the construction of the sheet module 100 are shown. Module 1000 can be a representative of any module in the connector, such as... Figure 7 and Figure 8 Any module in modules 810A…810D shown. Each module in modules 810A…810D may have the same overall structure, and some parts may be the same for all modules. For example, the contact tail region 820 and the mating contact region 840 may be the same for all modules. Each module may include a middle region 830, but the length and shape of the middle region 830 may vary depending on the position of the module within the sheet.

[0139] In the illustrated embodiment, module 1000 includes a pair of signal conductors 1310A and 1310B held within an insulating housing portion 1100. Figure 13 The 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 may have parts that engage with each other. Alternatively or additionally, reference conductors 1010A and 1010B may have parts that engage with the insulating housing portion 1100. As yet another example, when components 900A and 900B are as follows... Figure 7 When fastened together as shown, the reference conductor can remain in place.

[0140] Figure 10 The exploded view shows that the mating contact area 840 includes sub-regions 1040 and 1042. Sub-region 1040 includes the mating contact portion of module 1000. When mated with pin module 300, the mating contact portion of pin module 300 enters sub-region 1040 and engages with the mating contact portion of module 1000. These components can be sized to support a "functional mating range" such that if module 300 and module 1000 are fully pressed together, the mating contact portion of module 1000 will slide along the pin of pin module 300 to the "functional mating range" distance during mating.

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

[0142] If modules 300 and 1000 are in their standard mating position, fully pressed together in this embodiment, the pins will be located within the mating contacts of the signal conductor of module 1000. The impedance of the signal conductor in sub-region 1040 will still depend primarily on the configuration of sub-region 1040, thus providing impedance matching the rest of module 1000.

[0143] The pin module 300 can contain a sub-region 340 ( Figure 3 In sub-region 340, the impedance of the signal conductors will be determined by the construction of the 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 the 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 rated 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, which interact with components of the mating modules and can thus influence the impedance. Since the positioning of these components affects the impedance, the impedance can vary depending on the separation between the mating modules. In some embodiments, these components are positioned to reduce impedance changes regardless of the separation distance, or the effect of impedance changes is reduced by varying their distribution within the mating regions.

[0145] When pin module 300 is fully pressed against module 1000, the components in sub-regions 342 and 1042 can engage to provide a 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 mat, even if these modules are separated by an amount equal to the functional mating range, such that the separation between modules can cause a change in impedance relative to the rated value at one or more locations along the signal conductors in the mating region. Appropriate shape and positioning of these components can reduce this change or mitigate its effect by varying their distribution within portions of the mating region.

[0146] exist Figure 3 and Figure 10 In the embodiment shown, sub-region 1042 is designed to overlap the pin module 300 when module 1000 is fully pressed against the pin module 300. The dimensions of protruding insulating members 1042A and 1042B are respectively defined to fit within spaces 342A and 342B. When the modules are pressed together, the distal ends of insulating members 1042A and 1042B press against surface 450. Figure 4 These distal ends may have a shape complementary to the taper of surface 450 such that insulating members 1042A and 1042B fill spaces 342A and 342B, respectively. The overlap creates relative positions for the signal conductor, dielectric, and reference conductor, which may be close to the structure within sub-region 340. These components may be sized to provide the same impedance as 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 a standard mating position), the signal conductor will have the same impedance throughout the mating region comprised of the overlap between sub-regions 340, 1040, and sub-regions 342 and 1042.

[0147] These components can also be sized and have material properties that provide impedance control based on the separation of modules 300 and 1000. Impedance control can be achieved by providing approximately the same impedance in sub-regions 342 and 1042, even if these 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 by protruding insulating members 1042A and 1042B, which fully or partially overlap module 300 according to the separation between modules 300 and 1000. These protruding insulating members can reduce the magnitude of change in the relative permittivity of the material of the pins surrounding the 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 the portion of the signal conductor pair and the 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 approaches the rated impedance of the connector or does not change abruptly in a manner that could cause signal reflection. Other parameters of either or both of the mating modules can be configured for such impedance control.

[0149] Go to Figure 11 Further details of exemplary components of module 1000 are shown. Figure 11 This is an exploded view of module 1000, which does not show reference conductors 1010A and 1010B. In the illustrated embodiment, the insulating housing portion 1100 is made of multiple components. The central member 1110 may be molded from an insulating material. The 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, can 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 conductive elements 1310A and 1310B within recesses 1212A and 1212B and have a controllable separation from reference conductors 1010A and 1010B. In the illustrated embodiment, covers 1112 and 1114 can be formed of the same material as the central member 1110. However, it is not required that the materials be the same, and in some embodiments, different materials may be used to provide different relative permittivity in different regions, thereby providing the desired impedance of the signal conductor.

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

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

[0153] Region 1150 includes transition regions such as 822 or 842, wherein the waveguide is formed by a reference conductor transitioning from the widest dimension in the middle to a narrower dimension, plus a portion of the narrower intermediate region 830. Therefore, at least a portion of the waveguide formed by the reference conductor in said region 1150 has the same widest dimension W as in the intermediate region 830. Having at least a portion with a physical transition in the narrower portion of the waveguide reduces the energy coupled into undesirable waveguide propagation modes.

[0154] Having full 360-degree shielding of the signal conductor in region 1150 can also reduce the energy coupled into undesirable waveguide propagation modes. Therefore, in the illustrated embodiment, 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, separate from the central member 1110, are shown. For clarity, covers 1112 and 1114 are not shown. In this view, the transition region 1312A between the contact tail 1330A and the intermediate portion 1314A is visible. Similarly, the transition region 1316A between the intermediate portion 1314A and the mating contact portion 1318A is also visible. Similar transition regions 1312B and 1316B are visible for conductive element 1310B, thereby allowing edge coupling at the contact tail 1330B and the mating contact portion 1318B, and wide-side coupling at the intermediate portion 1314B.

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

[0157] In the illustrated embodiment, the mating contact portion is tubular. This shape can be formed by stamping conductive elements from a metal sheet and then rolling the mating contact portion into a tubular shape. The outer perimeter of the tube can be large enough to accommodate the pins of the mating pin module, but can only conform to the pins. The tube can be divided into two or more segments to form a flexible beam. Figure 12 Two such beams are shown. Raised portions or other protrusions can be formed in the distal portions of the beams to create contact surfaces. These contact surfaces can be coated with gold or other conductive, malleable materials to improve the reliability of the electrical contact.

[0158] When conductive elements 1310A and 1310B are mounted in the central member 1110, mating contacts 1318A and 1318B are fitted into openings 1220A and 1220B. The mating contacts are separated by a wall 1230. The distal ends 1320A and 1320B of the mating contacts 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 protrusions 1042A and 1042B can be formed as part of portion 1110, for example, in a molding process. However, any suitable technique can be used to form these components.

[0159] Figure 12Other techniques, as alternatives to or supplements to the above-described techniques, are shown 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 may be incorporated into each module to reduce the excitation or suppression of undesired modes. Figure 12 For example, a loss region 1215 is shown. Loss region 1215 can be configured to descend along a centerline between signal conductors 1310A and 1310B in some or all of regions 1150. Since signal conductors 1310A and 1310B bend through this region in different directions to perform an edge-to-wide-side transition, loss region 1215 may not be defined by a surface parallel or perpendicular to the walls of the waveguide formed by the reference conductor. Instead, the loss region can be formed as a surface 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 suspended.

[0160] Although shown as loss region 1215, similarly positioned conductive regions can also reduce the energy coupled into undesirable waveguide modes that reduce signal integrity. In some embodiments, such a conductive region having a torsion through region 1150 can be connected to a reference conductor. While not limited to any particular operating theory, a conductor used to separate the signal conductor and thus torsion to follow the torsion of the signal conductor in the transition region can couple ground current 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 signal conductor coupled via the wide side, rather than exciting common modes.

[0161] Figure 13The positioning of conductive members 1310A and 1310B forming a pair of signal conductors 1300 is shown in more detail. In the illustrated embodiment, each of conductive members 1310A and 1310B has an edge and a wide side located between these edges. Contact tails 1330A and 1330B are aligned in 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 sheet will similarly have contact tails aligned along column 1340. Contact tails of adjacent sheets will be aligned in parallel columns. The space between parallel columns creates a routing channel on the printed circuit board to which the connector is attached. Mating contacts 1318A and 1318B are aligned along column 1344. Although the mating contacts are tubular, a portion of the conductive elements 1310A and 1310B to which mating contacts 1318A and 1318B are attached is edge-coupled. Therefore, the mating contacts 1318A and 1318B can be similarly referred to as edge coupling.

[0162] Conversely, the middle portions 1314A and 1314B are aligned with the wide edges of the middle portions facing each other. The middle portions are aligned in the direction of row 1342. Figure 13 In the example, the conductive element for the right-angle connector is shown as a right angle between columns 1340 and 1344 folded back, where column 1340 represents the point attached to the daughter card and column 1344 represents the position of the mating pin for attachment to the baseplate connector.

[0163] In conventional right-angle connectors used in edge-coupled pairs within a thin sheet, the conductive element in the outer row at the daughter card is longer in each pair. Figure 13 In the middle section, conductive element 1310B is attached to the outer row of the daughter card. However, since the middle section is coupled via a wide edge, the middle sections 1314A and 1314B are parallel in the right-angled portion of the entire connector, resulting in no conductive element in the outer row. Therefore, the different electrical path lengths do not introduce offset.

[0164] In addition, Figure 13In this paper, other techniques for avoiding offset are introduced. Although the contact tail 1330B of conductive element 1310B is located in the outer row along column 1340, the mating contact portion (matting contact portion 1318B) of conductive element 1310B is located in the shorter inner row along column 1344. Conversely, the contact tail 1330A of conductive element 1310A is located in the inner row along column 1340, but the mating contact portion 1318A of conductive element 1310A is located in the outer row along column 1344. Therefore, the longer path length for a signal that moves relative to 1330A closer to contact tail 1330B can deviate from the shorter path length for a signal that moves relative to mating contact portion 1318A closer to mating contact portion 1318B. Therefore, the techniques shown can further reduce offset.

[0165] Figure 14A and Figure 14B Edge coupling and wide-side coupling within the same pair of signal conductors are shown. Figure 14A This is a side view shown along the direction of line 1342. Figure 14B This is the end view shown along the direction of column 1344. Figure 14A and Figure 14B The transition between the edge-coupled mating contact portion and the contact tail and the middle portion coupled via the wide side is shown.

[0166] Other details of the mating contacts, such as 1318A and 1318B, are also visible. The tubular portion of the mating contact 1318A... Figure 14A The tubular portion that mates with contact portion 1318B is visible in the view shown. Figure 14B The beams (of which beams 1420 and 1422 in mating contact 1318B are numbered) are also visible in the view shown.

[0167] The inventor has recognized and understood Figure 6 Component 630 is suitable for many applications, but when used over large areas, small gaps are likely to occur between the conductive shielding portions. For example, small gaps may appear at different locations between the conductive portion of component 630 and the surface ground pad on the PCB, and / or between the conductive portion of component 630 and the reference conductor 1010 on the wafer module 810. Small gaps can undesirably affect signal integrity and introduce signal crosstalk, especially when used in ultra-high density interconnect systems carrying UHF signals. Small gaps can cause energy from differential modes supported by differential conductors to leak outside the waveguide formed by the reference conductor, resulting in signal loss. Small gaps may also lead to unwanted mode conversions at the connector interface with the PCB. Figure 15 pass Figure 17B and Figures 22A to 22BDescribes a flexible shielding component that can reduce signal loss and mode switching.

[0168] Figure 15 An embodiment of a two-piece flexible shield 1500 that can be used with multiple sheet modules is shown. For simplicity of the figures, the flexible shield is shown as being used with six differential conductor pairs, but the 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 of a rigid or robust polymer, and the flexible conductive member may be formed of a conductive elastomer. The insulating portion 1504 may be configured to receive a contact tail of the sheet module 1310. The flexible conductive member may be configured to abut against the insulating portion and provide an electrical connection between a reference conductor 1010 on the sheet module 1310 and a reference pad (not shown) on the PCB. In some cases, the insulating portion 1504 may be omitted, and the flexible conductive member 1506 may abut against an end of the sheet module.

[0170] The insulating portion 1504 may be a molded or cast part, and in some embodiments may be planar. In some implementations, the insulating portion may include, for example... Figure 15 The surface structure depicted in the text, and having a first-order 1508 that can be approximately planar. In some cases, such as... Figure 16 As shown, the first stage may have an opening 1512 for receiving the end of the sheet module 130. The opening 1512 may be sized and shaped to receive a protrusion 1502 extending from and connected to a reference conductor 1010 of the sheet module. As shown, the protrusion 1502 extends over the reference conductor 1010. The protrusion may be electrically connected to a surface pad 1910 on a printed circuit board via a flexible shield 1500. In some embodiments, the protrusion may be adjacent to the contact tail of a signal conductor that also extends from the connector. In the illustrated embodiment, two protrusions are aligned parallel to column 1340 at one edge of the contact tail region 820, and two protrusions are aligned parallel to column 1340 at opposite edges of the contact tail region 820. One or more protrusions may be formed and arranged in any suitable manner.

[0171] The insulating portion may include a plurality of raised islands 1510 extending a distance d1 from the first stage. These islands may have walls 1516 extending from the first stage 1508 and supporting the islands above the first stage. Channels or recesses 1518 may be formed on the edges of the islands 1510, sized and shaped to receive protrusions 1502 of the sheet module. The island edges at the recesses 1518 may provide backing for the ends of the protrusions 1502, thereby allowing lateral forces to be applied to the protrusions. When the insulating portion is mounted above the ends of the sheet module, the ends of the protrusions 1502 may 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 and allow the contact tails 610 to pass through. In some embodiments, the multiple contact slots may have two closed ends. In some embodiments, the multiple contact slots may have one closed end and one open end. For example, each island 1510 has four contact slots with one open end for receiving four contact tails of the sheet module. In some embodiments, the aspect ratio of the contact slots may be between 1.5:1 and 4:1. The contact slots 1514A and 1514B may be arranged as repeating patterns of sub-patterns. 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 may be formed of a material having a dielectric constant of the desired impedance of the signal conductor in the mounting interface of the connector. In some embodiments, the relative permittivity may be in the range of 3.0 to 4.5. In some embodiments, the relative permittivity may be higher, for example, in the range of 3.4 to 4.5. In some embodiments, the relative permittivity of the island may 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 permittivity can be achieved by selecting adhesive materials and fillers. For example, known materials can be selected to provide a relative permittivity of up to 4.5. Relative permittivity in these ranges can result in the island having a higher dielectric constant than the insulating housing of the connector. In some embodiments, the island may have a relative permittivity that is at least 0.1, 0.2, 0.3, 0.4, 0.5, or 0.6 higher than the connector housing. In some implementations, the difference in relative permittivity 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 may include a plurality of openings 1520, which are sized and shaped to receive the island 1510 when mounted onto the insulating portion 1504. In some embodiments, the openings 1520 are sized and shaped such that when mounted over the insulating portion 1504, the inner wall of the flexible conductive member 1506 contacts and extends through the reference protrusion 1502 and the reference contact tail of the island 1510.

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

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

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

[0178] A suitable flexible conductive member 1506 may have a volume resistivity between 0.001 and 0.020 ohm-cm. Such a material may have a hardness on the Shore A scale in the range of 35 to 90. Such a material may be a conductive elastomer, such as a silicone elastomer filled with conductive particles such as silver, gold, copper, nickel, aluminum, nickel-coated graphite, or combinations thereof or alloys thereof. Non-conductive fillers, such as glass fibers, may also be present. Alternatively or additionally, the conductive flexible material may be partially conductive or exhibit resistive loss, such that it would be considered a detrimental material as described above. This result can be achieved by filling all or part of the elastomer or other adhesive with different types or amounts of conductive particles to provide the volume resistivity associated with the material described above as "detrimental". In some embodiments, the conductive flexible member may have an adhesive backing so that it can be bonded to the insulation portion 1504. In some embodiments, the flexible conductive member 1506 may be a core cut from a sheet of conductive elastomer having suitable thickness, electrical properties, 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 of a conductive elastomer and include a single layer of material.

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

[0180] Figure 17A and Figure 17BA conductive flexible member 1506, according to some embodiments, is shown mounted around island 1510. When the connector is pressed onto the PCB, the protrusion 1502 can be electrically connected to surface pads 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 extends laterally toward the island wall 1516, abutting against the protrusion 1502 and the reference contact tail. Figure 17B The view shows the circuit board-facing surface of the flexible shield 1500, and also shows four reference contact tails and differential contact tails extending through contact slots 1514A and 1514B of the two sheet modules. The area between 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 a line and at least two additional contact slots 1515. The longer dimension of the contact slots 1515 is disposed in a line parallel to the line perpendicular to the pair of contact slots 1514A, 1514B. In some embodiments, the contact tails 610 of each module are arranged such that the contact tail of the signal conductor is located at the center and the contact tail of the shield is located at the outer periphery. In some embodiments, contact slots 1514A, 1514B are positioned to receive the contact tail 610 carrying the signal conductor, and contact slot 1515 is positioned to receive the contact tail carrying the reference conductor.

[0182] Figure 18 A connector footprint 1800 on a printed circuit board 1802 according to some embodiments is shown, to which a connector as described herein may be mounted. Figure 18 The pattern of vias 1805 and 1815 in a printed circuit board is shown. As described above, the contact tail of connector 600 can be mounted to vias 1805 and 1815. Figure 18 The via pattern shown can correspond to, for example... Figure 15 The pattern of the contact tail of the sheet module 1310 shown. A module footprint 1820 of a sheet module may include a repeating via pattern on the surface of PCB 1802 to form a connector footprint. Figure 15 The situation is similar to that of the connectors shown; for larger connectors, there may be more than six module footprints.

[0183] Module footprint 1820 may 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 may be arranged around the pair of signal vias. In the illustrated embodiment, the pair of reference vias are located at opposite ends of the pair of signal vias. The illustrated pattern arranges the reference vias in columns aligned with the column orientation of the connector, with routing path areas 1830 between each column. This configuration also provides a relatively wide routing path area within the printed circuit board that is easily accessible by differential signal pairs, enabling high-density interconnects with desired high-frequency performance.

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

[0185] The inventors have recognized and understood that, in embodiments where the printed circuit board includes a conductive surface layer such as surface pad 1910 that contacts a grounded conductive structure within a connector or other component to a grounded conductive structure within the printed circuit board, shadow vias can be positioned to shape the current flowing through the conductive surface layer. Conductive shadow vias can be placed near a contact point on the conductive surface layer of a component connected to the grounded structure of the connector. This positioning of the shadow via limits the length of the primary conductive path from that contact point to the via that couples the current flowing into the inner ground layer of the printed circuit board. Limiting the flow of current in the ground conductor in a direction parallel to the surface of the circuit board, 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 20Implementation methods and Figure 19 The implementation differs in that a pair of shadow vias 2010 are incorporated into the module footprint 2020 adjacent to vias for differential signal conductors 1805A, 1805B. The shadow vias 2010 can be electrically connected to surface pads 1910. The shadow vias can also be electrically connected to one or more internal reference layers (e.g., ground planes) of the printed circuit board, such that the surface pads are also electrically connected to the ground plane via the shadow vias. When the connector is mounted, the conductive flexible material 1506 can press against the reference protrusion 1502 and the surface pads 1910 above the shadow vias 2010, thereby creating a substantially direct conductive path from the reference protrusion through the flexible shield to the surface pads, the shadow vias, and then to one or more reference layers of the printed circuit board.

[0187] Shadow vias 2010 may 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, which passes through signal vias 1805A and 1805B in the direction of column 1340. The first line 2022 may be located between signal vias 1805A and 1805B, such that the pair of shadow vias are equidistant from signal vias 1805A and 1805B. In embodiments where each module footprint 2020 includes more shadow vias, the shadow vias may be aligned with the signal vias in a direction perpendicular to the first line 2022.

[0188] The shadow via 2022 may at least partially overlap with the via 1912. In another embodiment, 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 slotted shadow vias.

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

[0190] In some embodiments, shadow vias can be positioned such 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% smaller than the circuit board thickness.

[0191] In some embodiments, shadow vias can be positioned to provide a conductive path through the surface layer that is shorter than the average length of the conductive path for a signal between a connector, other components mounted on the circuit board, and the inner layers of the circuit board connecting the signal via to the conductive trace. In some embodiments, shadow vias can be positioned such that the conductive path through the surface layer can be 50%, 40%, 30%, 20%, or 10% shorter than the average length of the signal path.

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

[0193] Figure 21A A plan view of connector footprints 2100 on a printed circuit board 2102 according to some implementations is shown. For the illustrated embodiment, the outline of the flexible conductive member 1506 is shown by dashed lines. In the illustrated embodiment, conductive surface pads 2110 are patterned to have additional structures surrounding each module footprint 2120. For example, multiple repeating module sub-patterns connected by bridges 2106 may be present. Gaps 2104 may exist between the bridges, in which the flexible conductive member may deform. The bridges can be arranged to create short conductive paths between the flexible conductive member and reference vias and shadow vias connected to an internal reference or ground plane of the printed circuit board. For example, bridges 2106 can be patterned to conductively connect adjacent reference vias and adjacent shadow vias. By having raised bridges near the reference vias 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 vias and shadow vias can be enhanced near the vias. In some embodiments, the thickness d3 of the surface pads can be between 1 mil and 4 mils. In some implementations, the thickness of the surface pads 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 reference via 1815 of the module 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 reference via 1815 of the module can be completely covered by the flexible conductive member. In some embodiments, the shadow via 1805 of the module 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 shadow via of the module can be completely covered by the flexible conductive member.

[0195] Figure 21B It shows along Figure 21A The diagram shows a cross-sectional view taken by a cut line. Bridge 2106 and gap 2104 can alternate across the surface of printed circuit board 2102. During mounting, flexible conductive element 1506 can extend into the gap and press against the surface of the bridge near reference protrusion 1502 and reference contact tail. For reliable contact, the flexible conductive element can be compressed to an amount sufficient to account for any changes in the surface height of the circuit board when the connector is inserted and any changes in separation between the connector and the circuit board. In some embodiments, the deformation of the flexible conductive element can range from 1 mil to 10 mils. The gap provides a volume in which the flexible conductive element can deform, thereby allowing proper compression of the flexible conductive element and thus providing a more uniform amount of contact force between the flexible conductive element and the reference protrusion and pad on the printed circuit board. It should be understood that the gap can be created in any suitable manner to enable sufficient compression of the flexible conductive element. In another embodiment, for example, the gap can be created by removing a portion of the connector housing, such as the first stage 1508 of the insulation 1504.

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

[0197] Figure 22B It shows along Figure 22A The cross-sectional view is shown by the cut line. The contact tail 1330A of the differential signal conductor can be isolated from the protrusion 1502 by the insulating housing 1100. During installation, the flexible conductive member 2206 can press against the retainer 2210 (or member 900) and laterally deform 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 such that it can provide a backing for the end of the protrusion. In some embodiments, the retainer may have a portion that fills the area shown as opening 2204 and has a designed height to provide a backing for the end of the protrusion.

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

[0199] Furthermore, in the illustrated embodiment, the contact tail of the conductive element is press-fitted and has a neck 2302 occupying a space smaller than that of the opening 2306. The inventors have recognized and understand that air-filled spaces remaining in the opening can cause impedance spikes at the connector-to-PCB (not shown) mounting interface. To compensate for impedance spikes, a material with a dielectric constant higher than that of the insulating housing 1100 can be used to form the organizer. For example, the insulating housing can be formed of a material with a relative dielectric constant less than 3.5. The organizer can be formed of a material having a relative dielectric constant higher than 4.0, for example, in the range of 4.5 to 5.5. In some embodiments, the organizer can be formed by adding filler to a polymeric adhesive. For example, the filler can be sufficient titanium dioxide to obtain a relative dielectric constant within the desired range.

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

[0201] In some embodiments, protrusions 2402A and 2402B may be elastic and deformable when the connector mates with the board to accommodate manufacturing variations in separation between the board and the connector. The protrusions may be made of any suitable flexible conductive material, such as hyperelastic and shape memory materials. Reference conductor 1010 may 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 conductors in those portions, can control the impedance in those portions so that it approximates the nominal impedance of the connector or does not change abruptly in a manner that could cause signal reflection.

[0202] In some implementations, the 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 section that ensures a reliable connection between the flexible shield and the grounding structure in the connector and / or the printed circuit board over substantially all areas of the connector.

[0203] Figure 25AThis is an isometric view of a flexible shield 2500 that can be used with multiple sheet modules according to some embodiments. For simplicity, the flexible shield is shown as being used with an 8×4 array of sheet modules, but the invention is not limited to this array size.

[0204] Figure 25B yes Figure 25A An enlarged plan view of the area marked 25B, which may correspond to one of a plurality of sheet 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 first-sized openings 2506 through which the contact tails of a pair of differential signal conductors 1310A and 1310B pass and a second-sized opening 2508 through which the contact tail of a reference conductor passes. Flexible fingers 2516 may be resilient in a direction 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, openings 2506 and 2508 may be arranged as repeating patterns of sub-patterns. Each sub-pattern may correspond to a corresponding sheet module. Each sub-pattern may include at least one opening 2506 through which a signal conductor passes without contacting the conductive body portion, such that the signal conductor can be electrically isolated from the flexible shield. Each sub-pattern may include at least one opening 2508 through which a reference conductor passes. The opening 2508 may be positioned and sized such that the reference conductor can be electrically connected to the conductive body portion and thus electrically connected to the flexible shield. In the illustrated example, opening 2506 is an ellipse having a major axis 2512 and a minor axis 2514. 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, the longer dimension of which is set in a parallel line perpendicular to the longer axis of the opening 2506.

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

[0208] Other openings or components may be present in the body portion 2504. In some embodiments, the openings may be sized and positioned to allow protrusions 2402A and 2402B to pass through, such that the conductive body portion can be electrically connected to a reference conductor of the sheet module. Alternatively or additionally, the opening 2508 may have at least one dimension smaller than the corresponding dimension of the reference conductor inserted into the opening. The body portion 2504 adjacent to the opening may be shaped such that it bends or deforms when the reference conductor is inserted into the opening, allowing the reference conductor to be inserted, but once inserted, it provides a contact force on the reference conductor, resulting in 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. This contact can be formed by cutting through the body portion 2504, which is adjacent to the opening of the cantilever beam or torsion beam fixed to the body portion 2504 at both ends. Alternatively, the body portion can be shaped to have an opening defined by a segment that is compressed when the reference conductor is inserted.

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

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

[0211] When the connector mounting surface is positioned on the surface of the printed circuit board, the beam can bend from the plane of the conductive body portion 2504 by an amount exceeding the tolerance. For this beam shape, the free distal end of the beam will contact the surface of the printed circuit board as long as the connector is mounted on it, provided the connector is within the tolerance range. Furthermore, the beam will be at least partially compressed to ensure that it 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 It corresponds to Figure 25B The cross-sectional view of cut line 26 shows a flexible shield mounted to a connector (e.g., connector 600) according to some embodiments. In the uncompressed state, the conductive body portion 2504 of the flexible shield 2500 can be located a distance d1 away from the surface 2606 of the 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 pressed against the surface of the printed circuit board on which the connector will be mounted.

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

[0214] Figure 26B Another implementation is shown. Figure 26BIn this embodiment, the flexible shielding member has a damaged material layer 2604 in addition to a body portion 2504 that can be formed of metal. The damaged material can be 0.1 mm to 2 mm thick, or it can 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 Implementation methods and Figure 19 The implementation differs in that the shadow via 2710 is incorporated into the module footprint 2720 adjacent to the vias used for differential signal conductors 1805A and 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 of the printed circuit board (e.g., ground planes), such that the surface pads are also electrically connected to the ground plane via the shadow via. When the connector is mounted, the conductive body 2504 can press against the surface pad 1910 above the shadow via 2710, thereby creating a substantially direct conductive path from the reference protrusion through the flexible shield to the surface pad, the shadow via, and then to one or more reference layers of the printed circuit board.

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

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

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

[0219] In some embodiments, shadow vias can be positioned such 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% smaller than the circuit board thickness. Short conductive paths can be achieved by positioning the shadow vias at or near contact points, for example, between the conductive body portion 2504 and the conductive surface pad 1910.

[0220] In some embodiments, shadow vias can be positioned to provide a conductive path through the surface layer that is shorter than the average length of the conductive path for a signal between a connector, other components mounted on the circuit board, and the inner layers of the circuit board connecting the signal via to the conductive trace. In some embodiments, shadow vias can be positioned such that the conductive path through the surface layer can be 50%, 40%, 30%, 20%, or 10% shorter than the average length of the signal path.

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

[0222] The frequency range of interest can depend on the operating parameters of the system using this connector, but typically has an upper limit between approximately 15 GHz and 50 GHz, such as 25 GHz, 30 GHz, or 40 GHz. However, in some applications, higher or lower frequencies are of interest. Some connector designs may have a frequency range of interest that only spans a portion of this 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 shielding at the mounting interface will be more pronounced.

[0223] The operating frequency range of an interconnect system can be determined based on the range of frequencies at which the interconnect can be used while maintaining acceptable signal integrity. Signal integrity can be measured against several standards depending on the application the interconnect system is designed for. Some of these standards 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 standards are signal attenuation along a signal path or signal reflection from a signal path.

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

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

[0226] This document describes the design of an electrical connector that improves signal integrity for high-frequency signals, such as those in the GHz range, including up to approximately 25 GHz or up to approximately 40 GHz, up to approximately 50 GHz or up to approximately 60 GHz or up to approximately 75 GHz or higher, while maintaining high density, such as a spacing of 3 mm or less between adjacent mating contacts, for example, a center-to-center spacing between adjacent contacts in a row of contacts on the order of 1 mm to 2.5 mm, or 2 mm to 2.5 mm. The spacing between mating contacts in each row may be similar; however, it is not required that the spacing between all mating contacts in the connector be equal.

[0227] Flexible shielding can be used with connectors of any suitable configuration. In some implementations, connectors with a wide-side coupling configuration can be used to reduce offset. The wide-side coupling configuration can be used for at least the non-straight middle portion of the signal conductor, such as the middle portion of a right-angle connector that creates a 90-degree path.

[0228] While a wide-edge coupling configuration may be necessary for the middle portion of conductive components, a full or predominantly edge-coupled configuration can be used at the mating interface with another connector or at the attachment interface with the printed circuit board. Such a configuration, for example, facilitates the routing of signal traces from vias connecting to the contact tails of receiving connectors within the printed circuit board.

[0229] Therefore, the conductive elements within the connector can have transition regions at either end or both ends. In these transition regions, the conductive elements can be bent out of plane parallel to the width dimension of the conductive element. In some embodiments, each transition region can have a bend towards the transition region of another conductive element. In some embodiments, each conductive element is bent towards the plane of the other conductive element such that the ends of the transition regions are aligned in the same plane parallel to but between the planes of the respective conductive elements. To avoid contact in the transition regions, the conductive elements can also be bent away from each other in the transition regions. Thus, the conductive elements in the transition regions can be aligned edge-to-edge in a plane parallel to but offset from the planes of the respective conductive elements. Such a configuration can provide a balanced pair within the frequency range of interest, while simultaneously providing routing channels within the printed circuit board supporting high-density connectors or providing mating contacts at a certain spacing to facilitate the manufacture of mating contacts.

[0230] Although details of the specific configurations of the conductive elements, housing, and shielding members have been 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 this disclosure are not limited to the specific combinations shown in the accompanying drawings.

[0231] Therefore, given these embodiments, it should be understood that various modifications, alterations, and improvements can 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 invention. Thus, the foregoing description and figures are merely exemplary.

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

[0233] Manufacturing techniques can also vary. For example, an embodiment of the daughter card connector 600 is described, which is formed by arranging multiple sheets onto a reinforcing member. It is possible to form an equivalent structure by inserting multiple shielding members and signal jacks into a molded housing.

[0234] As another example, a connector formed by modules is described, each module containing a pair of signal conductors. It is not required that each module contains exactly one pair of signal conductors or that the number of signal pairs is the same in all modules of the connector. For example, modules with two or three pairs can be formed. Furthermore, in some embodiments, core modules with two, three, four, five, six, or more rows in a single-ended or differential pair configuration can be formed. Each connector, or each wafer in an embodiment where the connector is wafered, may include such a core module. To create a core module with more rows than the base module includes, additional modules may be coupled to it (e.g., each additional module has a smaller number of pairs, such as a single pair per module).

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

[0236] In some embodiments, the contact tail is shown as a press-fit "eyelet" type flexible section designed to fit within a via of a printed circuit board. However, other configurations, such as surface mount elements, spring-loaded contacts, solderable pins, etc., may also be used, as various aspects of the invention are not limited to the use of any particular mechanism for attaching the connector to a printed circuit board.

[0237] This disclosure is not limited to the details of the construction or arrangement of the components described above and / or 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. Furthermore, the terms and terminology used herein are for descriptive purposes and should not be considered limiting. The use of “comprising,” “including,” “having,” “containing,” or “involving” and variations thereof herein is intended to encompass the items listed below (or their equivalents) and / or to supplement them.

[0238] This disclosure includes, but is not limited to, the following technical solutions.

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

[0240] A conductive body portion including a plurality of openings sized and positioned for the contact tail of the electrical connector to pass through, wherein the conductive body portion provides a current flow path between a shield inside the electrical connector and a grounding structure of the printed circuit board.

[0241] 2. The flexible shielding component according to Scheme 1 includes:

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

[0243] Multiple openings, the multiple openings being sized and positioned to allow the contact tail of the electrical connector to pass through;

[0244] Part One; and

[0245] Multiple islands extending from the first part;

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

[0247] 3. The flexible shielding component according to Scheme 2, wherein:

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

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

[0250] 4. The flexible shielding component according to Scheme 3, wherein:

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

[0252] 5. The flexible shielding component according to Scheme 2, wherein:

[0253] The flexible conductive component is filled with conductive particles at the load point where a loss conductor is provided.

[0254] 6. The flexible shielding component according to Scheme 2, wherein:

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

[0256] 7. The flexible shielding component according to Scheme 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 the longer dimension of the line and at least two additional slots.

[0258] 8. The flexible shielding component according to Scheme 7, wherein:

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

[0260] 9. The flexible shielding component according to Scheme 1, comprising:

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

[0262] 10. The flexible shielding component according to Scheme 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 shielding component according to Scheme 9, wherein:

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

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

[0267] 12. The flexible shielding component according to Scheme 9, wherein:

[0268] The plurality of flexible fingers are elastic in one direction, wherein the contact tail of the connector is inserted into the plurality of openings in the conductive body portion of the flexible shield in that direction.

[0269] 13. The flexible shielding component according to Scheme 11, wherein:

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

[0271] 14. The flexible shielding component according to Scheme 9, wherein:

[0272] The flexible shielding component is made of a superelastic material.

[0273] 15. The flexible shielding component according to Scheme 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 shielding component according to Scheme 15, wherein:

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

[0277] 17. An electrical connector, comprising:

[0278] A plate mounting surface, the plate mounting surface including a plurality of contact tails extending from the plate mounting surface;

[0279] Multiple internal shielding components; and

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

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

[0282] The flexible shielding component includes

[0283] An insulating part with a wall; and

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

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

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

[0287] The wall includes multiple 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 shielding elements.

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

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

[0294] The plurality of internal shielding elements are arranged to separate adjacent pairs among the plurality of pairs.

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

[0296] The plurality of internal shielding components include the corresponding contact tails of the 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 separated from the contact tail of the second part.

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

[0300] The flexible shielding member includes a plurality of flexible fingers that are attached to and extend from the conductive body portion.

[0301] 25. An electronic device comprising:

[0302] Including the printed circuit board on the surface;

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

[0304] A surface parallel to the surface described above;

[0305] Multiple conductive elements extending through the surface;

[0306] Multiple internal shielding components; and

[0307] A flexible shielding element provides a current flow path between the plurality of internal shielding elements and the grounding structure of the printed circuit board.

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

[0309] The flexible shielding includes 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 among 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 component presses against the grounding pad.

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

[0314] The printed circuit board also includes:

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

[0316] The grounding pad is connected to a plurality of shadow vias on the grounding plane.

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

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

[0319] The shadow via is located in a repeating pattern at a second position, each of which has the same positioning relative to a corresponding first position.

[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 multiple modules;

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

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

[0325] The contact tails of each module are positioned in a certain pattern, wherein the contact tails of the signal conductors are in the center and the contact tails of the inner shield are on the periphery.

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

[0327] The printed circuit board includes a plurality of signal vias receiving the contact tail of the signal conductor and a plurality of ground vias receiving the contact tail of the internal shield; and

[0328] The plurality of shadow vias are configured such that at least one shadow via is positioned between the grounding vias of the contact tails of the internal shields that receive each of the plurality of modules.

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

[0330] Each module also includes at least one conductive structure extending from the respective internal shield and separated from the contact tail of the internal shield; and

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

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

[0333] Each module also includes at least one conductive structure extending from the respective internal shield and separated from the contact tail of the internal shield; and

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

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

[0336] The flexible shielding member 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 also 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 shielding component presses against the grounding pad.

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

[0345] The printed circuit board also includes:

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

[0347] The grounding pad is connected to a plurality of shadow vias on the grounding plane.

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

[0349] The conductive body portion of the flexible shield includes a plurality of openings in a repeating pattern at a first position, the plurality of openings being sized and positioned to allow the contact tails of the plurality of conductive elements to pass through.

[0350] The shadow via is located in a repeating pattern at a second position, wherein each of the second positions has the same positioning relative to the corresponding first position.

Claims

1. An assembly for a mounting interface of an electrical connector, configured for a plurality of signal contact elements and a plurality of reference conductors within the electrical connector to pass through the assembly for connection to a printed circuit board, the assembly comprising: Insulating portion, said insulating portion comprising: A plurality of first openings, the plurality of first openings being sized and positioned to allow passage of the plurality of signal contact elements from the electrical connector; and A plurality of second openings, the plurality of second openings being sized and positioned to allow the plurality of reference conductors from the electrical connector to pass through, wherein The plurality of first openings and the plurality of second openings are arranged in a repeating pattern of sub-patterns. Each sub-pattern includes a pair of first openings and one or more second openings surrounding the pair of first openings. Each of the plurality of first openings and the plurality of second openings is a slot having a ratio between the longer dimension and the shorter dimension of at least 2:1, and For each sub-pattern, the pair of first openings are a pair of slots aligned along a longer dimension of a first line.

2. The component according to claim 1, wherein, For each sub-style, One or more second openings surrounding the pair of first openings include a pair of slots aligned along a longer dimension of a second line perpendicular to the first line.

3. The component according to any one of claims 1 to 2, wherein The insulating portion includes one or more thicker sub-portions, and The plurality of first openings extend through the one or more thicker subsections.

4. The component according to any one of claims 1 to 2, wherein, For each sub-style, The one or more second openings surrounding the pair of first openings include at least one opening for at least one reference contact tail of the electrical connector and at least one opening for at least one reference protrusion of the electrical connector.

5. The component according to claim 4, wherein, For each sub-style, The at least one opening of at least one reference contact tail for the electrical connector and the at least one opening of at least one reference protrusion for the electrical connector extend in a direction perpendicular to each other.

6. The component according to any one of claims 1 to 2, comprising: A conductive portion is attached to the insulating portion, and the conductive portion is configured to provide a current flow path between the shield inside the electrical connector and the ground structure of the printed circuit board.

7. The component according to any one of claims 1 to 2, wherein The plurality of first openings and the plurality of second openings extend through the insulation portion.

8. An electrical connector, comprising: Multiple internal shielding components; A board mounting surface, the board mounting surface including a plurality of signal contact elements and a plurality of reference conductors, wherein the plurality of reference contact elements extend from the plurality of internal shielding elements and extend through the board mounting surface; as well as An assembly for the plate mounting surface, the assembly comprising Insulating portion, said insulating portion includes A plurality of first openings, the plurality of first openings being sized and positioned to allow the plurality of signal contact elements to pass through; as well as Multiple second openings, wherein the second openings are sized and positioned to receive the multiple reference conductors, wherein The plurality of signal contact elements and the plurality of reference conductors are arranged in a repeating sub-pattern. Each sub-pattern includes a pair of signal contact elements and one or more reference conductors configured to surround the pair of signal contact elements, and For each sub-style, Each signal contact element includes a wide side connected by edges, and The pair of signal contact elements are edge-coupled when aligned along the first line on the wide side.

9. The electrical connector according to claim 8, wherein, For each sub-style, Each reference contact element includes a wide side connected by edges, and At least two reference contact elements are edge-coupled when the wide edge is aligned with a second line perpendicular to the first line.

10. The electrical connector according to claim 9, wherein, For each sub-style, At least two reference contact elements are edge-coupled with their wide edges aligned parallel to the first line.

11. The electrical connector according to claim 10, wherein, For each sub-style, The wide side of each signal contact element is coupled to the wide side of the reference contact element and aligned with the reference contact element along a line parallel to the second line.

12. The electrical connector according to any one of claims 8 to 11, wherein, The component further includes a flexible shielding element, the flexible shielding element comprising... A conductive portion is attached to the insulating portion and configured to provide a current flow path between the plurality of internal shields and the grounding structure of the printed circuit board.

13. The electrical connector according to claim 12, wherein The insulating portion of the flexible shield includes one or more thicker sub-portions, and The plurality of signal contact elements pass through one or more thicker sub-sections of the insulation portion of the flexible shield.

14. The electrical connector according to claim 13, wherein The one or more thicker sub-sections are made of a material with a dielectric constant higher than that of the housing of the electrical connector, thereby establishing a desired impedance for the signal contact element.

15. An electronic system comprising an electrical connector according to any one of claims 8 to 14, combined with a printed circuit board, wherein, The printed circuit board includes at least one ground pad on a surface, and the electrical connector is mounted on the surface, wherein the component is adjacent to the surface such that a reference conductor within the electrical connector is electrically connected to the at least one ground pad through the plurality of second openings.

16. The electronic system according to claim 15, wherein, The printed circuit board includes: Multiple wiring layers; and Connector footprint, the connector footprint including: Multiple via patterns are configured in rows and columns, each via pattern including a pair of signal vias aligned along a first line and at least four ground vias configured to surround the pair of signal vias, and Multiple routing channel regions are located between perforated arrays, wherein each of the multiple routing channel regions is accessed by more than one signal pair.

17. The electronic system according to claim 16, wherein Each of the plurality of via patterns includes one or more shadow vias.

18. The electronic system according to claim 17, wherein, For each pattern of the zigzag, The one or more shadow vias include two shadow vias aligned in a direction parallel to the row.

19. The electronic system according to any one of claims 17 to 18, wherein, For each pattern of the zigzag, The one or more shadow vias include two shadow vias aligned in a direction parallel to the column.

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