Electrical connector with plated ground shield and connector system

Abstract

An electrical connector (14) includes a housing (54), signal contacts (30), and a ground shield (36). A signal contact (30) is coupled to the housing and positioned to mate with a mating signal contact (28) of a mating connector (12). A ground shield is coupled to the housing and at least partially surrounds the signal contacts to shield the signal contacts. The ground shield is plated with a ground material component (202) along one or more contact segments (39) of the ground shield that are in compression engagement with one or more other conductive members. The grounding material composition includes a tin-nickel (Sn / Ni) alloy coating (206). The signal contact is plated with a signal material component (302) different from the ground material component.

Description

[0001] This application is a divisional application of an invention patent application with an application date of September 27, 2019, application number 201910922294.6, and invention name “Electrical connector and connector system with plated ground shield”. Technical Field

[0002] The subject matter herein generally relates to electrical connectors having plated ground shields that shield signal contacts. Background Art

[0003] The electrical contacts of many known electrical connectors are often plated to improve the electrical performance and mechanical reliability of the connector. For example, the substrates of the signal contacts and ground contacts of a high-speed connector are often plated with one or more other materials, such as precious metals and their alloys, that can provide the contacts with lower contact resistance. However, plating the signal contacts and ground contacts of an electrical connector can be expensive, thereby increasing the cost of manufacturing the connector, especially when the plating includes expensive precious metals.

[0004] There is a need to reduce the cost of contacts for electrical connectors without sacrificing the electrical performance or durability of the electrical connectors. Summary of the invention

[0005] According to the present invention, an electrical connector is provided, which includes a housing, a signal contact and a ground shield. The signal contact is coupled to the housing and positioned to mate with a mating signal contact of a mating connector. The ground shield is coupled to the housing and at least partially surrounds the signal contact to shield the signal contact. The ground shield is plated with a grounding material component along one or more contact segments of the ground shield, and the one or more contact segments are compressed and engaged with one or more other conductive members. The grounding material component includes a tin-nickel (Sn / Ni) alloy plating. The signal contact is plated with a signal material component that is different from the grounding material component. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a perspective view of an embodiment of a connector system.

[0007] Figure 2 is a partially exploded perspective view of an embodiment of a receptacle connector of the connector system.

[0008] Figure 3 is a partially exploded perspective view of an embodiment of a plug connector of the connector system.

[0009] Figure 4 is an elevation view of a portion of a receptacle connector and a portion of a plug connector showing the connectors mated together.

[0010] Figure 5is a cross-sectional view of a ground shield of a plug connector according to an embodiment.

[0011] Figure 6 is a cross-sectional view of a signal contact of a plug connector according to an embodiment.

[0012] Figure 7 is an enlarged perspective view of one of the ground shields of the plug connector according to an embodiment.

[0013] Figure 8 is a perspective view of a plurality of ground shields of a header connector according to an alternative embodiment. DETAILED DESCRIPTION

[0014] At least some embodiments described herein include a signal contact configured to have a specified low level of contact resistance during operation and a ground shield (or ground contact) that is allowed to have a low level of contact resistance greater than the specified low level of contact resistance of the signal contact during operation. The total resistance experienced by the communication system includes the inherent (or body) resistance provided by the interface between the two conductors and the low level contact resistance (hereinafter referred to as "LLCR"). For example, the electrical contacts of the plug connector engage with the electrical contacts of the socket connector at the interface. The interface has an electrical contact resistance at the interface. The low level contact resistance or LLCR test method for measuring the resistance uses a low level of current and voltage to ensure that any insulating film that may exist is not broken or that the contact asperities are not melted by the resistance measurement process. The voltage and current used to measure or determine the LLCR can be, for example, 20mV (maximum) open circuit at 100mA.

[0015] The electrical contacts described herein may include a variety of different materials. For example, the electrical contacts may include a substrate, such as copper or a copper alloy (e.g., beryllium copper), which is plated or coated with one or more other materials. As used herein, when another material is "plated" or "coated" on a substrate, the other material may be directly in contact with or bonded to the outer surface of the substrate, or may be directly in contact with or bonded to the outer surface of an intermediate material. More specifically, the other material need not be directly adjacent to the substrate and may be separated by an intermediate layer.

[0016] Among other factors, LLCR may be related to the thickness of the coating. At least some embodiments described herein also include a ground shield having a coating and a signal contact having a coating. The coating of the ground shield and the coating of the signal contact may have different thicknesses. For example, the coating of the signal contact may have a thickness greater than the coating of the ground shield. After manufacturing, the LLCR of a ground shield having a thinner coating is more likely to increase.

[0017] LLCR corresponds to the interface between two surfaces that engage with each other. For example, a signal contact engages with a mating signal contact at a signal interface, and a ground shield engages with a mating ground shield at a ground interface. The LLCR of each interface can be measured by determining the current and / or voltage at two different points on opposite sides of the interface. LLCR generally increases over time and usage due to degradation processes. Degradation may occur, for example, through corrosion and wear, and by a reduction in the contact force that presses the two mating contacts against each other. These degradation processes reduce the total area of ​​the interface along which the two mating conductors directly engage with each other and effectively conduct current between them. Unlike signal contacts and ground shields in known systems, the signal contacts and ground contacts described herein may have substantially different LLCRs. For example, after a period of operation, the LLCR of the ground shield may be ten times (10X) the LLCR of the signal contact.

[0018] The electrical contact may include multiple layers. For example, the electrical contact may include a base layer (or substrate), one or more optional intermediate layers plated on the base layer, and an outer layer plated on the intermediate layer. The one or more intermediate layers may also be referred to as one or more inner layers.

[0019] The base layer of the electrical conductor may include copper or copper alloys or other metals or alloys, all of which are susceptible to corrosion. Such corrosion can be eliminated by plating the base material with one or more other materials. For example, a passive metal such as tin or nickel can be plated on the base layer. The passive metal can form an intermediate layer or barrier layer. A passive film (e.g., a thin oxide film) may form along the surface of the barrier layer. The passive film can provide corrosion resistance and act as a protective barrier between the barrier layer and the surrounding environment.

[0020] In some cases, a precious metal material (e.g., gold, gold alloys, palladium, palladium alloys, platinum, platinum alloys, silver, and / or silver alloys) is plated onto the substrate or onto the intermediate barrier layer. If the plating has a relatively small thickness (e.g., between 2 and 30 microinches (or 50.8 nm to 762 nm), depending on the material), the plating may be referred to as a "flash layer." With or without a flash layer, a pore blocking substance may be applied to the outer surface of the electrical contact. The pore blocking substance is configured to reduce corrosion along the outer surface and may have a nominal effect on LLCR.

[0021] Thus, embodiments may include a mating array having a plurality of signal contacts and a plurality of ground shields. The signal contacts and ground shields are positioned to mate with mating signal contacts and mating ground shields of a mating connector, respectively. The ground shields and signal contacts may be plated with different material compositions and / or layers having different thicknesses. Each material composition may have one or more layers.

[0022] For example, the ground shield may be plated with a ground material composition configured to produce a first low level contact resistance (LLCR) across the ground contact interface when mated with the mating ground shield during operation. The signal contact may be plated with a signal material composition configured to produce a second LLCR across the signal contact interface when mated with the mating signal contact during operation. During operation, the second LLCR may be less than the first LLCR, such that the resistance across the signal contact interface is less than the resistance across the ground contact interface.

[0023] As used herein, when different material components are "configured to produce" different LLCRs, then the different material components have different properties or qualities that result in differences between the LLCRs. In other words, the differences between the LLCRs are not caused solely by the contacts of another connector. The differences between the LLCRs may be primarily caused by the material components of the conductors. For example, the materials constituting the material components and / or the thickness of one or more plating layers of the material components may be selected so that differences in LLCR may occur. In some embodiments, the material components of the ground shield may be more cost-effective than the material components of the signal contacts. Furthermore, it should be understood that the phrase "configured to produce" does not mean merely a hypothetical or theoretical capability, but rather means the likelihood that the material components will produce LLCRs if the electrical connector is used as intended.

[0024] Because LLCR may increase over time, LLCR may be determined when the contact has a predetermined condition. For example, an accelerated-aging protocol may be used to determine LLCR occurring at end-of-life (EOL). LLCR at EOL may represent an approximate maximum value for LLCR.

[0025] For example, the grounding material component of the ground shield may be configured to produce a first LLCR between 100 milliohms and 25 ohms when mating with a mating ground shield during operation after applying an accelerated aging scheme. In at least one embodiment, the first LLCR at the ground interface between the grounding material component of the ground shield and the mating ground shield is always maintained within a specified resistance range between 0 and 10 ohms throughout the service life of the ground shield. The signal material component may be configured to produce a second LLCR of up to 10 milliohms when mating with a mating signal contact during operation after applying an accelerated aging scheme. In some embodiments, the first LLCR may be at least 10 times greater than the second LLCR after applying the accelerated aging scheme. In certain embodiments, the first LLCR may be at least 25 times greater than the second LLCR after applying the accelerated aging scheme. In a specific embodiment, the first LLCR may be at least 50 times greater than the second LLCR after applying the accelerated aging scheme.

[0026] Accelerated aging protocols may be provided by industry standard test methods. For example, one standard that may be used is Telcordia GR-1217-Core "Generic Requirements for Separable Electrical Connectors Used in Telecommunications Hardware". Such accelerated aging protocols may be designed to address one or more degradation mechanisms that may exist for electrical connectors. Accelerated aging protocols typically consist of tests or test sequences designed to address specific degradation mechanisms. When considering the outermost metal layer, degradation mechanisms specific to the outermost metal layer should be considered. Tests or test sequences targeting the outermost metal layer typically focus on wear and corrosion mechanisms.

[0027] The accelerated aging protocol may, for example, include at least one of: (a) repeatedly mating and unmating electrical contacts (see, e.g., EIA-364-TP09), thereby producing wear along the interface; (b) applying mechanical shock conditions (see, e.g., EIA-364-TP27); (c) applying random vibration conditions (see, e.g., EIA-364-TP28); (d) applying thermal shock cycles with significant changes in temperature (e.g., about 150 degrees Celsius) (see, e.g., EIA-364-TP29); (e) applying thermal shock cycles with significant changes in temperature (e.g., about 150 degrees Celsius) (see, e.g., EIA-364-TP30); (f) applying thermal shock cycles with significant changes in temperature (e.g., about 150 degrees Celsius) (see, e.g., EIA-364-TP40); (g) applying thermal shock cycles with significant changes in temperature (e.g., about 150 degrees Celsius) (see, e.g., EIA-364-TP50); (g) applying thermal shock cycles with significant changes in temperature (e.g., about 150 degrees Celsius) (see, e.g., EIA-364-TP6 ... -TP32); (e) applying cycles of repeated changes in ambient humidity (see, for example, EIA-364-TP31); (f) exposing electrical connectors or contacts to dust (see, for example, EIA-364-TP91); (g) exposing electrical contacts to sustained high temperatures (see, for example, EIA-364-TP17); and (h) applying mixed flowing gases (see, for example, EIA-364-TP17, EIA-364-TP09, EIA-364-TP65 Class IIA).

[0028] In some embodiments, immediately after manufacturing and before use or storage, the signal contacts may have an LLCR of at most 10 milliohms, or more specifically at most 5 milliohms. In some embodiments, at EOL, the signal contacts may be at most 10 milliohms. At EOL, the ground shield may have at most 10 ohms.

[0029] Although it is desirable for the plating to have a uniform thickness along the respective electrical contacts, this may be difficult to achieve. Therefore, the thickness of the layer refers to the average thickness of the area along which the two contacts are joined to each other. The average thickness can be determined using, for example, a scanning electron microscope (SEM).

[0030] LLCR can be measured using various test standards. For example, one standard that can be used to measure LLCR includes Telcordia GR-1217-Core "General Requirements for Separable Electrical Connectors Used in Telecommunications Hardware". Unless otherwise specified in the claims, LLCR at EOL is measured or determined in a manner consistent with Telcordia GR-1217-Core. Other standards may include EIA 364-23, MIL-STD-202, MIL-J-641, MIL-E-2036, MIL-STD-3885, or MIL-H-83511.

[0031] In certain embodiments, the electrical contacts provide a signal path for transmitting data signals. Embodiments may be particularly suitable for communication systems, such as network systems, servers, data centers, etc., where the data rate may be greater than ten (10) gigabits per second (Gbps) or greater than five (5) gigahertz (GHz). One or more embodiments may be configured to transmit data at a rate of at least 20 Gbps, at least 40 Gbps, at least 56 Gbps, or higher. One or more embodiments may be configured to transmit data at a frequency of at least 10 GHz, at least 20 GHz, at least 28 GHz, or higher. As used herein with respect to data transmission, the term "configured to" does not mean that it has only a hypothetical or theoretical sense of capability, but means that the embodiment is designed to transmit data at a specified rate or frequency over an extended period of time (e.g., an expected period of time for commercial use) and with a signal quality sufficient for its intended commercial use. However, it is contemplated that other embodiments may be configured to operate at a data rate less than 10 Gbps or at a frequency less than 5 GHz.

[0032] Various embodiments may be configured for certain applications. One or more embodiments may be configured for use in a backplane or midplane communication system. For example, one or more electrical connectors described herein may be similar to electrical connectors of the STRADA Whisper or Z-PACK TinMan product lines developed by TE Connectivity. The electrical connector may include a high-density array of electrical contacts. The high-density array may have, for example, 100 mm per 100 mm along a mating side or mounting side of the electrical connector. 2 At least 12 signal contacts. In a more specific embodiment, the high-density array may have a signal contact area per 100 mm. 2 At least 20 signal contacts. Non-limiting examples of some applications in which the embodiments described herein may be used include a host bus adapter (HBA), a redundant array of inexpensive disks (RAID), a workstation, a server, a storage rack, a high-performance computer, or a switch. Embodiments may also include an electrical connector that is a small connector. For example, the electrical connector may be configured to comply with a specific standard, such as, but not limited to, a small form-factor pluggable (SFP) standard, an enhanced SFP (SFP+) standard, a quad SFP (QSFP) standard, a C-type pluggable (CFP) standard, and a 10 Gigabit SFP standard commonly referred to as an XFP standard.

[0033] In order to distinguish similar elements in the specific embodiments and claims, various labels may be used. For example, an electrical connector may be referred to as a plug connector, a socket connector, or a mating connector. An electrical contact may be referred to as a plug contact, a socket contact, a mating contact, a signal contact, or a ground shield. As used herein, a signal contact generally refers to a conductor that transmits a signal (e.g., a control signal or data) via an electric current. As used herein, a ground shield generally refers to a conductor that transmits an electric current for a ground and / or return signal path. The term ground shield is not intended to represent a specific shape or size, and a ground shield may also be referred to as a ground conductor and a ground contact. When similar elements are marked with different labels, the different labels do not necessarily require structural differences.

[0034] Figure 1is a perspective view of an embodiment of a connector system 10. The connector system 10 includes a first electrical connector 12 and a second electrical connector 14, which are configured to mate together to establish an electrical connection between two circuit boards (not shown). The first electrical connector 12 and the second electrical connector 14 include corresponding mating interfaces 16 and 18, at which the connectors 12 and 14 are configured to mate together. The "electrical connector" mentioned herein may refer to either the first electrical connector 12 or the second electrical connector 14. In the illustrated embodiment, the first electrical connector 12 may be a socket connector, and the second electrical connector 14 may be a plug connector. The first electrical connector 12 is also referred to herein as a socket connector 12, and the second electrical connector 14 is also referred to herein as a plug connector 14.

[0035] The socket connector 12 is configured to be mounted to one of the circuit boards along a mounting interface 20 of the socket connector 12. Similarly, the plug connector 14 is configured to be mounted to the other circuit board along a mounting interface 22 of the plug connector 14. In the illustrated embodiment, the mounting interface 20 of the socket connector 12 is oriented generally perpendicular to the mating interface 16 of the socket connector 12, and the mounting interface 22 of the plug connector 14 is oriented generally parallel to the mating interface 18 of the plug connector 14. Thus, when the socket connector 12 is mated with the plug connector 14, the circuit boards are oriented generally perpendicular to each other. However, in other embodiments, other orientations are possible.

[0036] Figure 2 1 is a partially exploded perspective view of an embodiment of a socket connector 12. The socket connector 12 includes a housing 24 that holds a plurality of contact modules 26. The contact modules 26 are held in a stacked configuration that is generally parallel to one another. The contact modules 26 hold a plurality of signal contacts 28 that extend along the mating interface 16 to engage with the plug connector 14 (e.g., Figure 1 The corresponding mating signal contact 30 (as shown) Figure 3 ) mate. Optionally, as shown in the illustrated embodiment, the signal contacts 28 are arranged in pairs carrying differential signals. In the illustrated embodiment, the contact modules 26 are oriented generally along a vertical plane. However, in other embodiments, other orientations are possible. For example, in some embodiments, the contact modules 26 are oriented generally along a horizontal plane.

[0037] The housing 24 is made of a dielectric material, such as, but not limited to, a plastic material and / or the like. The housing 24 includes a plurality of signal contact openings (not shown) and a plurality of ground contact openings (not shown) extending along the mating interface 16. The contact module 26 is mounted to the housing 24 so that the signal contacts 28 are received in corresponding signal contact openings. When received in corresponding signal contact openings, the signal contacts 28 define a portion of the mating interface 16 of the socket connector 12. Optionally, a single signal contact 28 is received in each signal contact opening. When the socket connector 12 is mated with the plug connector 14, the signal contact openings also receive corresponding mating signal contacts of the plug connector 14.

[0038] The signal contact openings and thus the signal contacts 28 can be arranged in any pattern. In the illustrated embodiment, the signal contact openings are arranged in an array of rows and columns. The columns are generally oriented vertically and the rows are generally oriented horizontally; however, in other embodiments, other orientations are possible. In the illustrated embodiment, the signal contacts 28 within each differential pair are arranged in the same column, so that the socket connector 12 defines a pair-in-column socket connector. In other embodiments, the signal contacts 28 within each differential pair are arranged in the same row, so that the socket connector 12 defines a pair-in-row socket connector.

[0039] Each contact module 26 includes a dielectric carrier 38 that holds an array of signal conductors. The carrier 38 may be overmolded over the array of signal conductors, although other manufacturing processes may additionally or alternatively be used to form the carrier 38. Optionally, the signal conductors are stamped and formed as an integral lead frame prior to overmolding the carrier 38. After overmolding, portions of the lead frame connecting the conductors are removed to provide individual conductors in an array held by the carrier 38. Additionally or alternatively, other manufacturing processes may be used to form the signal conductors.

[0040] The signal conductors include signal contacts 28, a plurality of mounting contacts 40, and intermediate segments or leads (not shown) connecting the signal contacts 28 to corresponding mounting contacts 40. The signal contacts 28, leads, and mounting contacts 40 define a signal path through the contact module 26. In the illustrated embodiment, the signal contacts 28 include a socket-type mating end having a socket configured to receive the pin-type contact 30 of the plug connector 14. Other types, structures, and / or the like of signal contacts 28 may be provided in other embodiments.

[0041] The mounting contacts 40 are configured to be mounted to a corresponding circuit board in an electrical contact manner to electrically connect the signal contacts 28 to the circuit board. When the contact module 26 is mounted to the housing 24 of the socket connector 12, the mounting contacts 40 extend along (and define a portion of) the mounting interface 20 of the socket connector 12 for mounting the socket connector 12 to the circuit board. In the illustrated embodiment, the mounting contacts 40 are compliant eye-of-needle (EON) pins, but any other type, structure, and / or the like of contacts may be used to mount the socket connector 12 to the circuit board, such as, but not limited to, other types of compliant pins, solder tails, surface mounting structures, and / or the like.

[0042] The socket connector 12 includes a ground shield 32 within the contact module 26. The ground shield 32 provides impedance control along the signal path and / or provides electrical shielding for the signal contacts 28 to prevent electromagnetic interference (EMI) and / or radio frequency interference (RFI). The ground shield 32 includes one or more contact segments 33, which are compressed and engaged with one or more other conductive members. For example, each contact segment 33 is close to another conductive member and is continuously engaged with the conductive member by pressure without being permanently bonded (e.g., soldered, welded, etc.) to the conductive member or fixed to the conductive member via fasteners, etc. Some non-limiting examples of compression engagement include press fit, mating via a deflectable spring beam, interference fit, etc.

[0043] Each ground shield 32 includes a body 42 that extends from a front end 44 to a rear end 46. The body 42 also extends from a mounting end 48 to an opposite end 50. The body 42 of the ground shield 32 is conductive and configured to provide impedance control and / or shield the signal contacts 28 from electromagnetic interference (EMI) and / or radio frequency interference (RFI). Specifically, when the ground shield 32 is mounted to the corresponding dielectric carrier 38, the body 42 extends over and around at least a portion of the corresponding signal conductor of the contact module 26.

[0044] The ground shield 32 includes a mating segment (or mating contact segment) 34 representing one of the contact segments 33. The mating segment 34 is configured to mate with a corresponding mating ground shield 36 (eg, mating contact segment) of the plug connector 14 at a separable mating interface. Figure 3 The mating segments 34 are spring beams that are deflectable. The contact modules 26 are mounted to the housing 24 so that the mating segments 34 of the ground shields 32 are received in corresponding ground contact openings. Optionally, a single mating segment 34 is received in each ground contact opening. When the receptacle connector 12 is mated with the plug connector 14, the ground contact openings also receive corresponding mating ground shields 36 of the plug connector 14 therein.

[0045] The mating segment 34 extends along a front end 44 of the body 42 of the ground shield 32. Figure 2 As should be apparent from the description herein, in the illustrated embodiment, the mating segments 34 are electrically connected together by the body 42 of the ground shield 32. However, alternatively, the mating segments 34 are not electrically connected together. When the ground shield 32 is mounted to a corresponding carrier 38 of a corresponding contact module 26, the mating segments 34 define a portion of the mating interface 16 of the socket connector 12. In the illustrated embodiment, the mating segments 34 include spring beams. Other types, structures, and / or the like of the mating segments 34 may be provided in other embodiments.

[0046] The ground shield 32 may include a mounting segment (or mounting contact segment) 52 representing one of the contact segments 33 of the ground shield 32. The mounting segment 52 extends along the mounting end 48 and is configured to be mounted to a corresponding circuit board in electrical contact therewith to electrically connect the ground shield 32 to a ground plane (not shown) of the circuit board. When the contact module 26 including the ground shield 32 is mounted to the housing 24 of the socket connector 12, the mounting segment 52 extends along (and defines a portion of) the mounting interface 20 of the socket connector 12 for mounting the socket connector 12 to the circuit board. In the illustrated embodiment, the mounting segment 52 is a compliant eye-of-needle (EON) pin that is press-fit inserted into a conductive hole (e.g., a plated through hole or through-hole) of the circuit board. However, alternatively or additionally, any other type, structure, and / or the like of contact may be used to mount the socket connector 12 to the circuit board, such as, but not limited to, other types of compliant pins, solder tails, surface mounting structures, and / or the like.

[0047] Although not in Figure 2, but the ground shield 32 may also include a coupling segment (or coupling contact segment) representing one contact segment 33 of the ground shield 32. The coupling segment of the ground shield 32 engages with an adjacent ground shield 32 of the socket connector 12. For example, the coupling segment may include a tab, a bridge, a skewer, etc. that extends from the body 42 of the ground shield 32 through the contact module 26 and engages an adjacent ground shield 32. The adjacent ground shields 32 may be mounted on the same contact module 26 along opposite sides of the contact module 26, or may be mounted on different contact modules 26. The coupling segment engages with the adjacent ground shield 32 by compression engagement, for example due to a biasing spring force that maintains contact between the coupling segment and the adjacent ground shield 32. The coupling segment of one ground shield 32 may engage the body 42 of the adjacent ground shield 32 or the coupling segment of the adjacent ground shield 32. The coupling segment electrically connects at least two adjacent ground shields 32 together, which makes the ground shields 32 common potential. Optionally, the coupling segments may extend across multiple contact modules 26 of the connector 12 , thereby engaging and electrically connecting more than two ground shields 32 .

[0048] Figure 3 1 is a partially exploded perspective view of an embodiment of the plug connector 14. The plug connector 14 includes a housing 54 that holds the signal contacts 30 and the ground shields 36 of the plug connector 14. The housing 54 is made of a dielectric material, such as, but not limited to, a plastic material and / or the like. In the illustrated embodiment, the housing 54 of the plug connector 14 includes a receptacle 56 that receives the receptacle connector 12 ( Figure 2 ) of the housing 24 (such as Figure 2 shown).

[0049] like Figure 3 As shown, the signal contacts 30 extend along the mating interface 18 of the plug connector 14 to mate with corresponding mating signal contacts 28 (eg, Figure 2 ) as shown. Optionally, as shown in the illustrated embodiment, the signal contacts 30 are arranged in pairs that carry differential signals. The signal contacts 30 may be arranged in any pattern. In the illustrated embodiment, the signal contacts 30 are arranged in an array of rows and columns; however, in other embodiments, other orientations are possible. In the illustrated embodiment, the signal contacts 30 include pins; however, other types, structures, and / or the like of signal contacts 30 may be provided in other embodiments.

[0050] The signal contacts 30 of the plug connector 14 include signal mounting ends 58 extending along (and defining a portion of) the mounting interface 22 of the plug connector 14 for mounting the plug connector 14 to a corresponding circuit board. Specifically, the signal mounting ends 58 are configured to be mounted to the corresponding circuit board in an electrical contact manner to electrically connect the signal contacts 30 to the circuit board. In the illustrated embodiment, the signal mounting ends 58 are compliant eye-of-needle (EON) pins, but any other type, structure, and / or the like of contacts may be used to mount the plug connector 14 to the circuit board, such as, but not limited to, other types of compliant pins, solder tails, surface mounting structures, and / or the like.

[0051] The ground shield 36 of the plug connector 14 provides impedance control and / or electrical shielding against EMI and / or RFI for the signal contacts 30. Specifically, the ground shield 36 surrounds at least a portion of the corresponding signal contacts 30 of the plug connector 14. The ground shield 36 has one or more contact segments 39 that are in compressive engagement with one or more other conductive members. For example, the ground shield 36 may include a mating segment 37 (e.g., a mating contact segment) representing one of the contact segments 39. The mating segment 37 extends along (and defines a portion of) the mating interface 18 of the plug connector 14 to mate with a corresponding ground shield 32 (e.g., a mating contact segment) of the receptacle connector 12. Figure 2 In the illustrated embodiment, the ground shield 36 forms a common potential (i.e., electrically connected) ground structure between the connectors 12 and 14. In the illustrated embodiment, the ground shield 36 is electrically connected to at least some adjacent ground shields 36 via the bridge 60. In the illustrated embodiment, the ground shields 36 within the same row R are electrically connected together. However, alternatively, the ground shields 36 are not electrically connected together. In the illustrated embodiment, the ground shield 36 includes a blade structure; however, other types, structures, and / or the like of ground shields 36 may be provided in other embodiments.

[0052] The ground shield 36 of the plug connector 14 may include a mounting segment 62 (e.g., a mounting contact segment) that represents another contact segment 39. The mounting segment 62 extends along (and defines a portion of) the mounting interface 22 of the plug connector 14 and is used to mount the plug connector 14 to a corresponding circuit board. Specifically, the mounting segment 52 is configured to be mounted to a corresponding circuit board in electrical contact therewith to electrically connect the ground shield 36 to a ground plane (not shown) of the circuit board. In the illustrated embodiment, the ground mounting segment 62 is a compliant eye-of-needle (EON) pin, but any other type, structure, and / or the like of contact may be used to mount the plug connector 14 to the circuit board, such as, but not limited to, other types of compliant pins, solder tails, surface mounting structures, and / or the like.

[0053] Although not in Figure 3 , but at least some of the ground shields 36 may include coupling segments that engage with the ground shields 36 in adjacent rows R via compression engagement to electrically common the ground shields 36 of the multiple rows R.

[0054] Figure 4 1 is a front view of a portion of the receptacle connector 12 and a portion of the plug connector 14, showing the connectors 12 and 14 mated together. Figure 4 As shown, the mating segments 34 of the visible ground shield 32 of the receptacle connector 12 mate with the corresponding mating segments 37 of the ground shield 36 of the plug connector 14 at the corresponding ground interface. The mating segments 34 of the ground shield 32 are integrally connected together by the body 42 of the ground shield 32. In addition, the ground shields 36 of the plug connector 14 are electrically connected together by the bridge 60. Therefore, Figure 4 The mating segments 34 of the illustrated ground shield 32 and the mating segments 37 of the illustrated ground shield 36 define four parallel resistive paths P1 - P4 across the ground interface when mated.

[0055] Reference again Figure 2 and 3 The signal contacts 28 of the receptacle connector 12 and the signal contacts 30 of the plug connector 14 are plated with one or more materials to improve the electrical performance and / or mechanical reliability of the signal contacts 28 and 30. For example, the signal contacts 28 and / or 30 may be plated with one or more materials that provide the signal contacts 28 and / or 30 with a lower contact resistance and / or plated with one or more materials that increase the durability of the signal contacts 28 and / or 30, thereby reducing the wear caused by repeated mating and contact mating of the connectors 12 and 14. Providing the signal contacts 28 and / or 30 with a lower contact resistance may include, but are not limited to, plating the signal contacts 28 and 30 with a material having a relatively high electrical conductivity and a relatively low electrical resistance, plating with a material that can resist, inhibit, and / or reduce corrosion, and / or the like. Increasing the durability of the signal contacts 28 and / or 30 may include, but are not limited to, plating the signal contacts 28 and / or 30 with a material having a relatively high hardness, plating with a material that can resist, inhibit, and / or reduce corrosion, and / or the like.

[0056] The signal contacts 28 and 30 can be made of any substrate, such as but not limited to copper, copper alloys, and / or the like. The signal contacts 28 and 30 can include any number of plating layers on the substrate. Each plating layer can have any thickness, and its thickness can be selected to provide one or more electrical and / or mechanical properties (such as but not limited to durability, conductivity, resistance, impedance, elasticity, and / or the like) for a particular signal contact 28 or 30. Examples of materials that can be plated on the signal contacts 28 and 30 include materials that inhibit, resist, and / or reduce corrosion, materials with relatively high electrical conductivity and relatively low resistance, and / or materials with relatively high hardness. These materials may include precious metals, precious metal alloys, nickel (Ni), nickel alloys, and / or the like. For example, precious metals may include gold (Au), silver (Ag), palladium (Pd), platinum (Pt) and alloys thereof.

[0057] The ground shield 32 of the receptacle connector 12 and the ground shield 36 of the plug connector 14 may be plated with one or more materials to improve the electrical performance and / or mechanical reliability of the ground shield 32 and the ground shield 36. In some embodiments, the ground shield 32 and / or the ground shield 36 are not plated with any material (i.e., no plating is deposited on the base material of the ground shield 32 and / or the ground shield 36), as will be briefly discussed below.

[0058] The ground shields 32 and 36 have different platings than the signal contacts 28 and 30. Specifically, the platings of the signal contacts 28 and 30 may include at least one material that is different from any one of the plating materials of the ground shields 32 and 36. In other words, in some embodiments, the platings of the ground shields 32 and 36 lack one or more materials included in the platings of the signal contacts 28 and 30. Conversely, the platings of the signal contacts 28 and 30 may lack one or more materials included in the platings of the ground shields 32 and 36. In addition to or in lieu of lacking one or more materials, the platings of the ground shields 32 and 36 may differ from the platings of the signal contacts 28 and 30 because they contain different amounts of one or more of the same materials. For example, the platings of the ground shields 32 and 36 may include a thinner layer of material than a corresponding layer of the same material in the signal contact platings. The ground shields 32 and 36 may have any number of platings on their substrates, which may be greater than, equal to, or less than the number of platings of the signal contacts 28 and 30.

[0059] Figure 5 FIG. 1 is a cross-sectional view of one of the ground shields 36 of the plug connector 14 according to an embodiment. Figure 3 The line 5-5 in FIG. 5 is intercepted. The line 5-5 is in the mating section 37 (such as the ground shield 36) of the ground shield 36. Figure 337 . The ground shield 36 is plated with a grounding material component 202 along the mating segment 37. In the illustrated embodiment, the ground shield 36 includes a substrate 204, and the grounding material component 202 is plated on the substrate 204. The grounding material component 202 may include a plurality of layers, such as an outer plating 206 and an intermediate plating 208 disposed between the substrate 204 and the outer plating 206. For example, an inner surface of the intermediate plating 208 may be engaged with the substrate 204, and an outer surface of the intermediate plating 208 may be engaged with the outer plating 206. The outer plating 206 may represent the outermost metal layer of the ground shield 36 along the mating segment 37. For example, the ground shield 36 may optionally have a non-metallic substance, such as a pore blocking lubricant, along the outer plating 206. The pore blocking lubricant may prevent fretting corrosion due to vibration during operation.

[0060] In the illustrated embodiment, the base material 204 of the ground shield 36 may be or include copper, a copper alloy (e.g., beryllium copper), stainless steel, a silver nickel (Ag / Ni) alloy, etc. The middle plating 208 of the ground material component 202 may be or include nickel or a nickel alloy, such as palladium nickel. In at least one embodiment, the middle plating 208 is nickel and may be referred to herein as a nickel plating 208. The nickel plating 208 may serve as a protector for the base material 204, for example, by preventing oxidation of the base material 204. The nickel plating 208 may increase the durability of the ground shield 36.

[0061] The outer plating 206 of the ground material component 202 is a tin-nickel (Sn / Ni) alloy and may be referred to herein as a tin-nickel alloy plating 206. The tin-nickel alloy plating 206 may contain at least half by weight (or mass) of tin. For example, the tin-nickel alloy plating 206 may include between about 55 wt% and about 75 wt% tin and between about 25 wt% and about 45 wt% nickel. For example, excluding any unavoidable impurities, the tin content and the nickel content may represent the balance of the plating 206. Note that the nickel content of the nickel plating 208 is separate and distinct from the nickel content in the tin-nickel alloy plating 206. As used herein, the value mentioned before the term "about" includes the stated value and / or a value greater than and less than the stated value within a specified error or threshold range (e.g., within 0.5% or 1% of the stated value). In a specific embodiment, the tin-nickel alloy plating 206 contains about 65 wt% tin and about 35 wt% nickel. Tin-nickel alloy is a stable alloy that is relatively simple to apply. For example, the LLCR of the tin-nickel alloy plating 206 may be maintained within a specified resistance range throughout the service life of the ground shield 36. The specified resistance range may be between 0 and 10 ohms, such that the resistance of the plating 206 does not exceed 10 ohms even at the end of service life (EOL) of the ground shield 36. The tin-nickel alloy plating 206 may be more stable than some known plating materials, which may have LLCR values ​​that significantly increase to over 10 ohms throughout the service life.

[0062] The plating layers 206, 208 of the ground material composition 202 may have any respective thicknesses, which may be selected to provide one or more electrical and / or mechanical properties (e.g., but not limited to, durability, conductivity, resistance, impedance, elasticity, and / or the like) to the ground shield 36. For example, in an embodiment, the tin-nickel alloy plating layer 206 may have a thickness between about 5 micro-inches and about 100 micro-inches (or about 127 nm to about 2540 nm).

[0063] Although the grounding material component 202 in the illustrated embodiment has two plating layers 206, 208, in alternative embodiments, the grounding material component 202 may have only one layer or at least three plating layers. For example, in an alternative embodiment, the tin-nickel alloy plating layer 206 may be the only layer, such that the plating layer 206 is deposited directly on the substrate 204, or the grounding material component 202 may include a second intermediate plating layer between the outer tin-nickel alloy plating layer 206 and the substrate 204.

[0064] Figure 6 FIG. 1 is a cross-sectional view of one of the signal contacts 30 of the plug connector 14 according to an embodiment. Figure 36-6 in FIG. The signal contact 30 is plated with a signal material component 302. In the illustrated embodiment, the signal contact 30 includes a substrate 304, and the signal material component 302 is plated on the substrate 304. The signal material component 302 may include a plurality of layers, such as an outer plating layer 306 and an intermediate plating layer 308 disposed between the substrate 304 and the outer plating layer 306. The intermediate plating layer 308 may be plated directly on the substrate 304, and the outer plating layer 306 may be plated directly on the intermediate plating layer 308.

[0065] The substrate 304 may be, for example, copper or a copper alloy (e.g., beryllium copper). The intermediate plating 308 may include nickel and / or tin and may serve as a diffusion barrier between the substrate 304 and the outer plating 306. The outer plating 306 may include a noble metal or a noble metal alloy, such as palladium nickel, gold, a gold alloy, silver, a silver alloy, etc. The material of the outer plating 306 may be selected to provide a low contact resistance. For example, the material of the outer plating 306 may reduce or limit rust, corrosion, oxidation, other chemical processes, and / or the like. The outer plating 306 may have a thickness of, for example, more than 30 microinches (i.e., 762nm). In alternative embodiments, the signal material component 302 plated on the substrate 304 may include only one plating layer or at least three plating layers.

[0066] exist Figure 5 and Figure 6 In the illustrated embodiment, the plating of the ground shield 36 (e.g., the ground material component 202) is different from the plating of the signal contacts 30 (e.g., the signal material component 302). For example, in the illustrated embodiment, the ground material component 202 lacks one or more materials of the signal material component 302 that are selected to provide low contact resistance to the signal contacts 30. More specifically, the ground material component 202 lacks precious metals such as gold, silver, palladium, and platinum, while the signal material component 302 includes precious metals in the outer plating 306. Because precious metals are known to provide low contact resistance, the contact resistance (e.g., LLCR) of the signal contacts 30 having precious metals in the outer plating 306 can be lower than that of the ground shield 36 lacking precious metals. The ground material component 202 along the mating segment 37 of the ground shield 36 can be configured to produce a first LLCR when mated with the ground shield 32 of the socket connector 12 during operation, and the signal material component 302 of the signal contact 30 can be configured to produce a second LLCR that is less than the first LLCR when mated with the signal contact 28 of the socket connector 12 during operation. For example, the contact resistance (e.g., LLCR) of the signal contact 30 can be equal to or less than 10 milliohms, while the contact resistance (e.g., LLCR) of the ground shield 36 can be from about 20 milliohms to about 10 ohms.

[0067] Eliminating or reducing the plating materials selected to provide low contact resistance can reduce the cost of plating the ground shield 36, which can reduce the cost of manufacturing the plug connector 14. For example, precious metal plating materials that provide low contact resistance are relatively expensive (e.g., compared to more common metals such as copper and nickel). Eliminating precious metals from the plating of the ground shield 36 can significantly reduce the cost of plating the ground shield 36.

[0068] The higher contact resistance of the ground shield 36 relative to the signal contact 30 may not adversely affect the electrical performance of the plug connector 14 at relatively high frequencies (e.g., frequencies of at least 10 Gb). At relatively high frequencies, the magnitude of the resistance depends on, for example, the interface dimensions, plating materials, dielectric materials, surface roughness, skin effect, and / or the like. It should be understood that the impedance of the electrical interface at higher frequencies depends not only on direct current (DC) contact resistance, but also on capacitive and inductive coupling mechanisms. For example, due to the parallel resistance paths P1-P4 defined by the ground shield 36 (see above for reference), the impedance of the electrical interface at higher frequencies may be greater than the impedance of the ground shield 36. Figure 4 Description), the ground resistance will be reduced according to the parallel resistor equation. Specifically, the parallel ground resistance circuit of the parallel resistance paths P1-P4 will reduce the effect of any single relatively high resistance value at the individual ground contact interface.

[0069] Therefore, the ground shield 36 having a greater contact resistance than the signal contact 30 may not reduce the transmission speed or transmission quality of the plug connector 14. The contact resistance of the ground shield 36 may not inhibit the ability of the connector 14 to reliably transmit signals at a rate of at least 10 Gigabits. It has been recognized that although the contact resistance of the ground material component 202 of the ground shield 36 is greater than the contact resistance of the signal material component 302 of the signal contact 30, the contact resistance 202 of the ground material component is relatively stable throughout the service life of the ground shield 36 and remains within a specified acceptable resistance range. The specified acceptable resistance range may have an upper limit of 5 ohms, 10 ohms, or 15 ohms. In a specific embodiment, the upper limit of the acceptable resistance range is 10 ohms.

[0070] Figure 5 The ground material component 202 of the illustrated ground shield 36 may also include Figure 6 One or more materials not present in the signal material component 302 of the illustrated signal contact 30. For example, unlike the ground material component 202 having a tin alloy as the outer plating 206, the signal material component 302 may lack a tin-nickel alloy plating. For example, the signal contact 30 may lack a tin-nickel alloy material.

[0071] Figure 71 is an enlarged perspective view of one of the ground shields 36 of the plug connector according to an embodiment. The ground shield 36 is plated with a ground material component 202 along at least one of the contact segments 39 of the ground shield 36 (see FIG. 1 ). Figure 5 As described above, the contact segments 39 are areas of the ground shield 36 that compressively engage with one or more other conductive members (e.g., a mating ground shield 32, a printed circuit board, or an adjacent ground shield 36). During mating, installation, or assembly, the contact segments 39 may wipe against the corresponding conductive members. The contact segments 39 may be held in continuous engagement with the conductive members via pressure without the use of bonding (e.g., soldering, welding, etc.) or fasteners.

[0072] In the illustrated embodiment, the ground shield 36 has two contact segments 39 that are compression-engaged, including a mating segment 37 and a mounting segment 62. Both the mating segment 37 and the mounting segment 62 are plated with a grounding material component 202. For example, the base material 204 (eg, Figure 5 ) is plated with a nickel coating 208 ( Figure 5 ), then tin-nickel alloy plating 206 ( Figure 5 ) is plated on the nickel plated layer 208. For the purpose of illustration, Figure 7 The area of ​​the ground shield 36 having the ground material component 202 is marked. The tin-nickel alloy plating 206 can provide durability and stable contact resistance along the contact segment 39. For example, as described above, the contact resistance at the contact segment 39 can be maintained within a tolerable resistance range throughout the service life of the ground shield 36.

[0073] In the illustrated embodiment, the grounding material component 202 is not plated on the entire ground shield 36. For example, the ground shield 36 lacks the grounding material component 202 along a portion 402 of the ground shield 36 outside the contact segment 39. Figure 7 The portions 402 outside the contact segments 39 in the substrate 204 include the intermediate segments between the mating segments 37 and the mounting segments 62 and the bridges 60 that integrally connect the adjacent ground shields 36. The ground shields 36 along these portions 402 may be plated or may not be plated. In at least one embodiment, the substrate 204 is plated with the nickel plating 208 along the portions 402 outside the contact segments 39, but these portions 402 lack the tin-nickel alloy plating 206. For example, the tin-nickel alloy plating 206 may be located only along the contact segments 39, while the nickel plating 208 may surround the entire surface area of ​​the ground shield 36 (e.g., along the contact segments 39 and the portions 402 outside the contact segments 39).

[0074] In alternative embodiments, the grounding material component 202 may be plated only along the mating segment 37 or only along the mounting segment 62, but not both. For example, the grounding material component 202 may be plated along the mating segment 37, while the mounting segment 62 may have the same Figure 5 The ground material composition 202 shown is a different plating composition. In a non-limiting example, the substrate along the mounting segment can be plated with a middle layer of nickel, followed by an outer layer of tin (e.g., not a tin-nickel alloy). In another alternative embodiment, the ground material composition 202 can be plated along the entire ground shield 36, including the portion 402 outside the contact segment 39.

[0075] Figure 8 is a perspective view of a plurality of ground shields 36 of the header connector 14 according to an alternative embodiment. Figure 8 The ground shields 36 are shown aligned in a row. Figure 3 and Figure 7 The illustrated ground shield 36 is different because Figure 8 The ground shields 36 in a row are not integrally connected by the bridge 60. Instead, the ground shields 36 are discrete components having coupling segments 410 that engage adjacent ground shields 36 via compression engagement. In the illustrated embodiment, the coupling segments 410 are spring beams that extend parallel to the row and engage with outer surfaces of adjacent ground shields 36 in the row. Optionally, all or at least some of the ground shields 36 have a single coupling segment 410 that extends in a common direction to mechanically and electrically connect the ground shields 36 in a row without the need for chemical bonds or fasteners. The coupling segments 410 represent contact segments 39 and may be plated with a grounding material component 202, such as Figure 5 and 7 For example, in addition to or in lieu of plating the mating segment 37 and / or the mounting segment 62 with the grounding material component 202, the entire coupling segment 410 or at least the portion engaging the adjacent ground shield 36 may be plated with the grounding material component 202. In a non-limiting example embodiment, the mating segment 37, the mounting segment 62, and the coupling segment 410 are all plated with the grounding material component 202, such that these segments 37, 62, 410 include the following: Figure 5 A tin-nickel alloy plating layer 206 is shown.

[0076] although Figure 5 , 7 8 shows a grounding material component 202 plated on the grounding shield 36 of the plug connector 14. In addition to the grounding shield 36 of the plug connector 14, the grounding material component 202 may be plated on the grounding shield 32 of the socket connector 12. For example, referring to Figure 5 , 7The description of FIG. 8 can be applied to the ground shield 32 of the socket connector 12. The contact segment 33 (eg, Figure 2 ) can be plated with a grounding material component 202 so that the mating segment 34 ( Figure 2 ) and / or mounting section 52 ( Figure 2 ) is plated with at least one intermediate plating layer and then an outer plating layer, which is a tin-nickel alloy and represents the outermost metal layer. The intermediate plating layer can be a nickel plating layer. In an alternative embodiment, the grounding material composition 202 is plated on the ground shield 32 of the receptacle connector 12 instead of the ground shield 36 of the plug connector 14, so that the ground shield 36 of the plug connector 14 can have a different plating composition than the grounding material composition 202.

[0077] In addition, despite Figure 6 The signal material composition 302 is shown plated on the signal contacts 30 of the plug connector 14, and the signal material composition 302 may be plated on the signal contacts 28 of the receptacle connector 12 in addition to the signal contacts 30 of the plug connector. In an alternative embodiment, the signal material composition 302 is plated on the signal contacts 28 of the receptacle connector 12 instead of on the signal contacts 30 of the plug connector 14.

[0078] Although described and illustrated herein with respect to a socket connector 12 and a plug connector 14, the embodiments described and / or illustrated herein are not limited to a particular electrical connector, but may be used with any other type of electrical connector, such as, but not limited to, a cable connector, other types of circuit board connectors, and / or the like.

[0079] The embodiments described and / or illustrated herein can reduce the cost of plating ground contacts without sacrificing the electrical performance of the electrical connector including the ground contacts. The embodiments described and / or illustrated herein can provide an electrical connector that is cheaper to manufacture for a given electrical performance.

[0080] Embodiments described herein disclose a grounding material component plated on a grounding shield, which is a conductor that carries a ground (or return) current. The grounding material component includes a tin-nickel alloy plating that remains within an acceptable resistance range throughout the expected life of the electrical connector. The tin-nickel alloy plating may contain between about 55wt% and about 75wt% tin and between about 25wt% and 45wt% nickel. In a specific embodiment, the tin-nickel alloy contains 65wt% tin and 35wt% nickel. At the time of initial mating, the grounding material component with the tin-nickel alloy plating may produce a contact resistance of less than 1 ohm and remain relatively stable within an acceptable resistance range of less than 10 ohms throughout the expected life. In addition to reducing the cost of grounding shields with precious metal plating, the grounding material component disclosed herein may maintain performance characteristics even under low normal forces (e.g., 0.1N or less).

Claims

1. An electrical connector (14), comprising: Housing (54); signal contacts (30) coupled to the housing and positioned to mate with mating signal contacts (28) of a mating connector (12); and a ground shield (36) coupled to the housing and at least partially surrounding the signal contacts to shield the signal contacts; The ground shield is plated with a grounding material component (202) along one or more contact segments (39) of the ground shield, the one or more contact segments are compression-engaged with one or more other conductive components, the grounding material component includes a tin-nickel (Sn / Ni) alloy plating (206), and the signal contact is plated with a signal material component (302) different from the grounding material component.

2. An electrical connector (14) as described in claim 1, wherein the grounding material component (202) along the mating contact segment (37) of the ground shield (36) is configured to produce a first low level contact resistance (LLCR) when mating with the mating ground shield (32) of the mating connector (12) during operation, and the signal material component (302) is configured to produce a second LLCR when mating with the mating signal contact (28) of the mating connector during operation, wherein the second LLCR is less than the first LLCR.

3. The electrical connector (14) of claim 1, wherein the tin-nickel alloy plating (206) contains about 55 wt% to about 75 wt% tin and about 25 wt% to about 45 wt% nickel.

4. The electrical connector (14) of claim 1, wherein the tin-nickel alloy plating (206) contains about 65 wt% tin and about 35 wt% nickel.

5. The electrical connector (14) of claim 1, wherein the ground shield (36) lacks the ground material component (202) along a portion (402) of the ground shield outside of the one or more contact segments (39).

6. The electrical connector (14) of claim 1, wherein the tin-nickel alloy plating (206) is an outermost metal layer of the ground shield (36) along the one or more contact segments (39).

7. The electrical connector (14) of claim 1, wherein the grounding material component (202) includes a nickel plating layer (208) between a base material (204) of the grounding shield (36) and the tin-nickel alloy plating layer (206).

8. An electrical connector (14) as described in claim 1, wherein the ground shield (36) includes a substrate (204) and a nickel plating (208) covering the substrate along the entire surface area of ​​the ground shield, and wherein the tin-nickel alloy plating (206) covers the nickel plating only along one or more contact segments (39) of the ground shield.

9. The electrical connector (14) of claim 1, wherein the signal material component (302) of the signal contact (30) lacks a tin-nickel alloy plating.

10. The electrical connector (14) of claim 1, wherein the one or more contact segments (39) of the ground shield (36) include one or more of the following: (i) a mating segment (37) of the ground shield that engages a mating ground shield (32) of the mating connector (12) during mating, (ii) a mounting section (62) of the ground shield that is press-fit into a conductive hole in a circuit board, or (iii) a coupling segment (410) of the ground shield that engages an adjacent ground shield of the electrical connector.

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