Grounding structures for header and receptacle assemblies

A receptacle assembly includes a front housing configured for mating with a header assembly and a contact module coupled to the front housing. The contact module includes a conductive holder that has a first side and an opposite second side. The conductive holder has a front coupled to the front housing. The conductive holder holds a frame assembly. The frame assembly includes a plurality of contacts and a dielectric frame that supports the contacts. The dielectric frame is received in the conductive holder. The contacts extend from the conductive holder for electrical termination. A first ground shield is coupled to the first side, is electrically connected to the conductive holder and has grounding beams and grounding fingers that extend forward of the front of the conductive holder for electrical connection to a corresponding header shield of the header assembly. A second ground shield is coupled to the second side, is electrically connected to the conductive holder and has grounding beams and grounding fingers that extend forward of the front of the conductive holder for electrical connection to a corresponding header shield of the header assembly.

BACKGROUND OF THE INVENTION

The subject matter herein relates generally to grounding connector assemblies.

Some electrical systems utilize electrical connectors to interconnect two circuit boards, such as a motherboard and daughtercard. In some systems, to electrically connect the electrical connectors, a midplane circuit board is provided with front and rear header connectors on opposed front and rear sides of the midplane circuit board. Other systems electrically connect the circuit boards without the use of a midplane circuit board by directly connecting electrical connectors on the circuit boards.

However, as speed and performance demands increase, known electrical connectors are proving to be insufficient. Signal loss and/or signal degradation is a problem in known electrical systems. Additionally, there is a desire to increase the density of electrical connectors to increase throughput of the electrical system, without an appreciable increase in size of the electrical connectors, and in some cases, a decrease in size of the electrical connectors. Such increase in density and/or reduction in size causes further strains on performance.

In order to address performance, some known systems utilize shielding to reduce interference between the contacts of the electrical connectors. However, the shielding utilized in known systems is not without disadvantages. For instance, electrically connecting the grounded components of the two electrical connectors at the mating interface of the electrical connectors is difficult and defines an area where signal degradation occurs due to improper shielding at the interface. For example, some known systems include ground contacts on both electrical connectors that are connected together to electrically connect the ground circuits of the electrical connectors. Typically, the connection between the ground contacts is located at a single point of contact.

A need remains for an electrical system that provides efficient shielding to meet particular performance demands. A need remains for an electrical system that provides redundant grounding connections.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a receptacle assembly is provided having a front housing configured for mating with a header assembly. A contact module is coupled to the front housing. The contact module includes a conductive holder that has a first side and an opposite second side. The conductive holder has a front coupled to the front housing. The conductive holder holds a frame assembly. The frame assembly includes a plurality of contacts and a dielectric frame that supports the contacts. The dielectric frame is received in the conductive holder. The contacts extend from the conductive holder for electrical termination. A first ground shield is coupled to the first side. The first ground shield is electrically connected to the conductive holder. The first ground shield has grounding beams that extend therefrom. The first ground shield has grounding fingers that extend therefrom. The grounding beams and grounding fingers extend forward of the front of the conductive holder for electrical connection to a corresponding header shield of the header assembly. A second ground shield is coupled to the second side. The second ground shield is electrically connected to the conductive holder. The second ground shield has grounding beams that extend therefrom. The second ground shield has grounding fingers that extend therefrom. The grounding beams and grounding fingers extend forward of the front of the conductive holder for electrical connection to a corresponding header shield of the header assembly.

In another embodiment, a receptacle assembly is provided having a front housing configured for mating with a header assembly. The front housing has contact openings therethrough. A contact module is coupled to the front housing. The contact module includes a conductive holder that has a first side and an opposite second side. The conductive holder has a front coupled to the front housing. The conductive holder holds a frame assembly. The frame assembly includes a plurality of contacts and a dielectric frame that support the contacts. The dielectric frame is received in the conductive holder. The contacts extend from the conductive holder into corresponding contact openings for electrical termination to header contacts of the header assembly. A first ground shield is coupled to the first side. The first ground shield is electrically connected to the conductive holder. The first ground shield has grounding beams that extend therefrom. The first ground shield has grounding fingers that extend therefrom. The grounding beams and grounding fingers extend forward of the front of the conductive holder into corresponding contact openings for electrical connection to a wall and an edge, respectively, of a corresponding C-shaped header shield of the header assembly. A second ground shield coupled to the second side. The second ground shield is electrically connected to the conductive holder. The second ground shield has grounding beams that extend therefrom. The second ground shield has grounding fingers that extend therefrom. The grounding beams and grounding fingers extend forward of the front of the conductive holder into corresponding contact openings for electrical connection to a wall and an edge, respectively, of a corresponding C-shaped header shield of the header assembly.

In a further embodiment, an electrical connector assembly is provided having a header assembly that includes a header housing. A plurality of header contacts are held by the header housing, and a plurality of C-shaped header shields surround corresponding header contacts on three sides. The header shields have walls defining the C-shaped header shields and two edges at the ends of the C-shaped header shields. A receptacle assembly is matable to the header assembly. The receptacle assembly includes a front housing that is matable to the header housing. A contact module is coupled to the front housing. The contact module includes a conductive holder that has a first side and an opposite second side. The conductive holder has a front coupled to the front housing. The conductive holder holds a frame assembly. The frame assembly includes a plurality of contacts and a dielectric frame supporting the contacts. The dielectric frame is received in the conductive holder. The contacts extend from the conductive holder for electrical termination to corresponding header contacts. A first ground shield is coupled to the first side. The first ground shield is electrically connected to the conductive holder. The first ground shield has grounding beams that extend therefrom. The first ground shield has grounding fingers extending therefrom, the grounding beams extending forward of the front of the conductive holder for electrical connection to a corresponding wall of a corresponding header shield. The grounding fingers extend forward of the front of the conductive holder for electrical connection to corresponding edges of the header shield. A second ground shield is coupled to the second side. The second ground shield is electrically connected to the conductive holder. The second ground shield has grounding beams that extend therefrom. The second ground shield has grounding fingers that extend therefrom. The grounding beams extend forward of the front of the conductive holder for electrical connection to a corresponding wall of a corresponding header shield. The grounding fingers extend forward of the front of the conductive holder for electrical connection to corresponding edges of the header shield.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a perspective view of an exemplary embodiment of an electrical connector system100illustrating a receptacle assembly102and a header assembly104that may be directly mated together. The receptacle assembly102and/or the header assembly104may be referred to hereinafter individually as a “connector assembly” or collectively as “connector assemblies”. The receptacle and header assemblies102,104are each electrically connected to respective circuit boards106,108. The receptacle and header assemblies102,104are utilized to electrically connect the circuit boards106,108to one another at a separable mating interface. In an exemplary embodiment, the circuit boards106,108are oriented perpendicular to one another when the receptacle and header assemblies102,104are mated. Alternative orientations of the circuit boards106,108are possible in alternative embodiments.

A mating axis110extends through the receptacle and header assemblies102,104. The receptacle and header assemblies102,104are mated together in a direction parallel to and along the mating axis110.

The receptacle assembly102includes a front housing120that holds a plurality of contact modules122. Any number of contact modules122may be provided to increase the density of the receptacle assembly102. The contact modules122each include a plurality of receptacle signal contacts124(shown inFIG. 2) that are received in the front housing120for mating with the header assembly104. In an exemplary embodiment, each contact module122has a shield structure126for providing electrical shielding for the receptacle signal contacts124. In an exemplary embodiment, the shield structure126is electrically connected to the header assembly104and/or the circuit board106. For example, the shield structure126may be electrically connected to the header assembly104by extensions (e.g. beams or fingers) extending from the contact modules122that engage the header assembly104. The shield structure126may be electrically connected to the circuit board106by features, such as ground pins.

The receptacle assembly102includes a mating end128and a mounting end130. The receptacle signal contacts124are received in the front housing120and held therein at the mating end128for mating to the header assembly104. The receptacle signal contacts124are arranged in a matrix of rows and columns. In the illustrated embodiment, at the mating end128, the rows are oriented horizontally and the columns are oriented vertically. Other orientations are possible in alternative embodiments. Any number of receptacle signal contacts124may be provided in the rows and columns. The receptacle signal contacts124also extend to the mounting end130for mounting to the circuit board106. Optionally, the mounting end130may be substantially perpendicular to the mating end128.

The front housing120includes a plurality of signal contact openings132and a plurality of ground contact openings134at the mating end128. The receptacle signal contacts124are received in corresponding signal contact openings132. Optionally, a single receptacle signal contact124is received in each signal contact opening132. The signal contact openings132may also receive corresponding header signal contacts144therein when the receptacle and header assemblies102,104are mated. The ground contact openings134receive header shields146therein when the receptacle and header assemblies102,104are mated. The ground contact openings134receive grounding beams302,332(shown inFIG. 2) and grounding fingers303,340(shown inFIG. 2) of the contact modules122that mate with the header shields146to electrically common the receptacle and header assemblies102,104.

The front housing120is manufactured from a dielectric material, such as a plastic material, and provides isolation between the signal contact openings132and the ground contact openings134. The front housing120isolates the receptacle signal contacts124and the header signal contacts144from the header shields146. The front housing120isolates each set of receptacle and header signal contacts124,144from other sets of receptacle and header signal contacts124,144.

The header assembly104includes a header housing138having walls140defining a chamber142. The header assembly104has a mating end150and a mounting end152that is mounted to the circuit board108. Optionally, the mounting end152may be substantially parallel to the mating end150. The receptacle assembly102is received in the chamber142through the mating end150. The front housing120engages the walls140to hold the receptacle assembly102in the chamber142. The header signal contacts144and the header shields146extend from a base wall148into the chamber142. The header signal contacts144and the header shields146extend through the base wall148and are mounted to the circuit board108.

In an exemplary embodiment, the header signal contacts144are arranged as differential pairs. The header signal contacts144are arranged in rows along row axes153. The header shields146are positioned between the differential pairs to provide electrical shielding between adjacent differential pairs. In the illustrated embodiment, the header shields146are C-shaped and provide shielding on three sides of the pair of header signal contacts144. The header shields146have a plurality of walls, such as three planar walls154,156,158. The walls154,156,158may be integrally formed or alternatively, may be separate pieces. The wall156defines a center wall or top wall of the header shields146. The walls154,158define side walls that extend from the center wall156. The header shields146have edges160,162at opposite ends of the header shields146. The edges160,162are downward facing. The edges160,162are provided at the distal ends of the walls154,158, respectively. The bottom is open between the edges160,162. The header shield146associated with another pair of header signal contacts144provides the shielding along the open, fourth side thereof such that each of the pairs of signal contacts144is shielded from each adjacent pair in the same column and the same row. For example, the top wall156of a first header shield146which is below a second header shield146provides shielding across the open bottom of the C-shaped second header shield146. Other configurations or shapes for the header shields146are possible in alternative embodiments. More or less walls may be provided in alternative embodiments. The walls may be bent or angled rather than being planar. In other alternative embodiments, the header shields146may provide shielding for individual signal contacts144or sets of contacts having more than two signal contacts144.

FIG. 2is an exploded view of one of the contact modules122and part of the shield structure126. The shield structure126includes a first ground shield200and a second ground shield202. The first and second ground shields200,202electrically connect the contact module122to the header shields146(shown inFIG. 1). The first and second ground shields200,202provide multiple, redundant points of contact to the header shield146. The first and second ground shields200,202provide shielding on all sides of the receptacle signal contacts124.

The contact module122includes a holder214having a first holder member216and a second holder member218that are coupled together to form the holder214. The holder members216,218are fabricated from a conductive material. For example, the holder members216,218may be die-cast from a metal material. Alternatively, the holder members216,218may be stamped and formed or may be fabricated from a plastic material that has been metalized or coated with a metallic layer. By having the holder members216,218fabricated from a conductive material, the holder members216,218may provide electrical shielding for the receptacle assembly102. When the holder members216,218are coupled together, the holder members216,218define at least a portion of the shield structure126of the receptacle assembly102.

The holder members216,218include tabs220,221extending inward from side walls222,223thereof. The tabs220define channels224therebetween. The tabs221define channels225therebetween. The tabs220,221define at least a portion of the shield structure126of the receptacle assembly102. When assembled, the holder members216,218are coupled together and define a front226and a bottom228of the holder214.

The contact module122includes a frame assembly230held by the holder214. The frame assembly230includes the receptacle signal contacts124. The frame assembly230includes a pair of dielectric frames240,242surrounding the receptacle signal contacts124. In an exemplary embodiment, the receptacle signal contacts124are initially held together as lead frames (not shown), which are overmolded with dielectric material to form the dielectric frames240,242. Other manufacturing processes may be utilized to form the contact modules122other than overmolding a lead frame, such as loading receptacle signal contacts124into a formed dielectric body.

The dielectric frame240includes a front wall244and a bottom wall246. The dielectric frame240includes a plurality of frame members248. The frame members248hold the receptacle signal contacts124. For example, a different receptacle signal contact124extends along, and inside of, a corresponding frame member248. The frame members248encase the receptacle signal contacts124.

The receptacle signal contacts124have mating portions250extending from the front wall244and contact tails252extending from the bottom wall246. Other configurations are possible in alternative embodiments. The mating portions250and contact tails252are the portions of the receptacle signal contacts124that extend from the dielectric frame240. In an exemplary embodiment, the mating portions250extend generally perpendicular with respect to the contact tails252. Inner portions or encased portions of the receptacle signal contacts124transition between the mating portions250and the contact tails252within the dielectric frame240. When the contact module122is assembled, the mating portions250extend forward from the front226of the holder214and the contact tails252extend downward from the bottom228of the holder214.

The dielectric frame240includes a plurality of windows254extending through the dielectric frame240between the frame members248. The windows254separate the frame members248from one another. In an exemplary embodiment, the windows254extend entirely through the dielectric frame240. The windows254are internal of the dielectric frame240and located between adjacent receptacle signal contacts124, which are held in the frame members248. The windows254extend along lengths of the receptacle signal contacts124between the contact tails252and the mating portions250. Optionally, the windows254may extend along a majority of the length of each receptacle signal contact124measured between the corresponding contact tail252and mating portion250.

During assembly, the dielectric frame240and corresponding receptacle signal contacts124are coupled to the holder member216. The frame members248are received in corresponding channels224. The tabs220are received in corresponding windows254such that the tabs220are positioned between adjacent receptacle signal contacts124. The dielectric frame242and corresponding receptacle signal contacts124are coupled to the holder member218in a similar manner with the tabs221extending through the dielectric frame242.

The holder members216,218, which are part of the shield structure126, provide electrical shielding between and around respective receptacle signal contacts124. The holder members216,218provide shielding from electromagnetic interference (EMI) and/or radio frequency interference (RFI). The holder members216,218may provide shielding from other types of interference as well. The holder members216,218provide shielding around the outside of the frames240, and thus around the outside of all of the receptacle signal contacts124, such as between pairs of receptacle signal contacts124, as well as between the receptacle signal contacts124using the tabs220,221to control electrical characteristics, such as impedance control, cross-talk control, and the like, of the receptacle signal contacts124.

The first ground shield200includes a main body300. In the illustrated embodiment, the main body300is generally planar. The ground shield200includes grounding beams302and grounding fingers303extending forward from a front304of the main body300. In an exemplary embodiment, the grounding beams302are bent inward out of plane with respect to the main body300such that the grounding beams302are oriented perpendicular with respect to the plane defined by the main body300. The grounding beams302are bent inward toward the holder214. In an exemplary embodiment, the grounding fingers303are arranged in the plane defined by the main body300, however the grounding fingers303may be bent out of plane in alternative embodiments. In an exemplary embodiment, the main body300includes a jogged section305that jogs a front section of the main body300with respect to a rear section of the main body300. The front and rear sections extend parallel to one another and, while not exactly coplanar, together generally define a plane of the main body300. The jogged section305allows the front section to be positioned with respect to the rear section, such as to position the grounding fingers303and/or ground pins316in particular locations.

In an exemplary embodiment, the first ground shield200is manufactured from a metal material. The ground shield200is a stamped and formed part with the grounding fingers303being stamped and the grounding beams302being stamped and then bent during the forming process out of plane with respect to the main body300. Optionally, the main body300may extend vertically while the grounding beams302may extend horizontally, however other orientations are possible in alternative embodiments.

Each grounding beam302has a mating interface306at a distal end thereof. The mating interface306is configured to engage the corresponding header shield146. The grounding beam302includes one or more projections308extending therefrom. The projections308are configured to engage the conductive holder214when the ground shield200is coupled thereto. The grounding beams302are configured to extend forward from the front226of the holder214such that the grounding beams302may be loaded into the front housing120(shown inFIG. 1).

Each grounding finger303has a mating interface310at a distal end thereof. In an exemplary embodiment, the grounding fingers303have bumps312proximate to the distal ends that are upward facing and that define the mating interfaces310. The mating interfaces310are configured to engage the edges160(shown inFIG. 1) of corresponding header shields146. The grounding fingers303are configured to extend forward from the front226of the holder214such that the grounding fingers303may be loaded into the front housing120.

The grounding fingers303are offset horizontally and vertically with respect to the grounding beams302. The grounding fingers303may extend along the sides of the receptacle signal contacts124. The grounding fingers303may provide shielding between the receptacle signal contacts124and receptacle signal contacts124of an adjacent contact module122held in the receptacle assembly102. The grounding fingers303may be generally vertically aligned with receptacle signal contacts124in a corresponding row of the receptacle signal contacts124. The grounding fingers303may be vertically offset, such as below, the receptacle signal contacts124.

The first ground shield200includes a plurality of mounting tabs314extending inward from the main body300. The mounting tabs314are configured to be coupled to the holder member216. The mounting tabs314secure the first ground shield200to the first side wall222. The mounting tabs314engage the holder member216to electrically connect the first ground shield200to the holder member216. Any number of mounting tabs314may be provided. The location of the mounting tabs314may be selected to secure various portions of the first ground shield200, such as the top, the back, the front, the bottom, and the like of the first ground shield200to the holder member216. The engagement of the projections308with the holder214help to secure the ground shield200to the holder214.

The first ground shield200includes a plurality of ground pins316extending from a bottom318of the first ground shield200. The ground pins316are configured to be terminated to the circuit board106(shown inFIG. 1). The ground pins316may be compliant pins, such as eye-of-the-needle pins, that are through-hole mounted to plated vias in the circuit board106. Other types of termination means or features may be provided in alternative embodiments to couple the first ground shield200to the circuit board106.

In an exemplary embodiment, the ground pins316include internal ground pins320and external ground pins322. The internal ground pins320are configured to extend into the holder member216. The external ground pins322remain outside and along the first side wall222of the holder member216. The internal ground pins320are configured to be positioned between, and generally aligned with, the contact tails252. The internal ground pins320are generally located in the column of receptacle signal contacts124to provide shielding between the receptacle signal contacts held by the dielectric frame240. Optionally, the internal ground pins320may be stamped and then bent inward during the forming process out of plane with respect to the main body300. The internal ground pins320may include one or more projections (not shown) extending therefrom. The projections are configured to engage the conductive holder214when the ground shield200is coupled thereto.

The external ground pins322are offset with respect to the receptacle signal contacts outside of the envelope of the holder214. The external ground pins322are located to provide shielding between the receptacle signal contacts124of the contact module122and receptacle signal contacts124of an adjacent contact module122within the receptacle assembly102. For example, the external ground pins322are generally aligned with the interface between two adjacent contact modules122. The external ground pins322may be generally aligned with the plane of the main body300of the first ground shield200. Optionally, the external ground pins322may include a jogged section326that slightly shifts the external ground pins322out of the plane of the main body300, such as to align the external ground pins322with external ground pins of the adjacent contact module122.

The second ground shield202includes a main body330. In the illustrated embodiment, the main body330is generally planar. The second ground shield202includes grounding beams332and grounding fingers333extending forward from a front334of the main body330. In an exemplary embodiment, the grounding beams332are bent inward out of plane with respect to the main body330such that the grounding beams332are oriented perpendicular with respect to the plane defined by the main body330. The grounding beams332are bent inward toward the holder214. In an exemplary embodiment, the grounding fingers333are arranged in the plane defined by the main body330, however the grounding fingers333may be bent out of plane in alternative embodiments. In an exemplary embodiment, the main body330includes a jogged section335that jogs a front section of the main body330with respect to a rear section of the main body330. The front and rear sections extend parallel to one another and, while not exactly coplanar, together generally define a plane of the main body330. The jogged section335allows the front section to be positioned with respect to the rear section, such as to position the grounding fingers333and/or ground pins346in particular locations.

In an exemplary embodiment, the second ground shield202is manufactured from a metal material. The ground shield202is a stamped and formed part with the grounding fingers333being stamped and the grounding beams332being stamped and then bent during the forming process out of plane with respect to the main body330. Optionally, the main body330may extend vertically while the grounding beams332may extend horizontally, however other orientations are possible in alternative embodiments.

Each grounding beam332has a mating interface336at a distal end thereof. The mating interface336is configured to engage the corresponding header shield146. The grounding beam332includes one or more projections338extending therefrom. The projections338are configured to engage the conductive holder214when the ground shield202is coupled thereto. The grounding beams332are configured to extend forward from the front226of the holder214such that the grounding beams332may be loaded into the front housing120(shown inFIG. 1).

Each grounding finger333has a mating interface336at a distal end thereof. In an exemplary embodiment, the grounding fingers333have bumps342proximate to the distal ends that are upward facing and that define the mating interfaces340. The mating interfaces340are configured to engage the edges162(shown inFIG. 1) of corresponding header shields146. The grounding fingers333are configured to extend forward from the front226of the holder214such that the grounding beams332may be loaded into the front housing120.

The grounding fingers333are offset horizontally and vertically with respect to the grounding beams332. The grounding fingers333may extend along the sides of the receptacle signal contacts124. The grounding fingers333may provide shielding between the receptacle signal contacts124and receptacle signal contacts124of an adjacent contact module122held in the receptacle assembly102. The grounding fingers333may be generally vertically aligned with receptacle signal contacts124in a corresponding row of the receptacle signal contacts124. The grounding fingers333may be vertically offset, such as below, the receptacle signal contacts124.

The second ground shield202includes a plurality of mounting tabs344extending inward from the main body330. The mounting tabs344are configured to be coupled to the holder member218. The mounting tabs344secure the second ground shield202to the second side wall223. The mounting tabs344engage the holder member218to electrically connect the second ground shield202to the holder member218. Any number of mounting tabs344may be provided. The location of the mounting tabs344may be selected to secure various portions of the second ground shield202, such as the top, the back, the front, the bottom, and the like of the second ground shield202to the holder member218. The engagement of the projections338with the holder214help to secure the ground shield202to the holder214.

The second ground shield202includes a plurality of ground pins346extending from a bottom348of the second ground shield202. The ground pins346are configured to be terminated to the circuit board106(shown inFIG. 1). The ground pins346may be compliant pins, such as eye-of-the-needle pins, that are through-hole mounted to plated vias in the circuit board106. Other types of termination means or features may be provided in alternative embodiments to couple the second ground shield202to the circuit board106.

In an exemplary embodiment, the ground pins346include internal ground pins350and external ground pins352. The internal ground pins350are configured to extend into the holder member218. The external ground pins352remain outside and along the second side wall223of the holder member218. The internal ground pins350are configured to be positioned between, and generally aligned with, the contact tails252. The internal ground pins350are located in the column of receptacle signal contacts124to provide shielding between the receptacle signal contacts held by the dielectric frame242. Optionally, the internal ground pins350may be stamped and then bent inward during the forming process out of plane with respect to the main body300. The internal ground pins350include one or more projections354extending therefrom. The projections354are configured to engage the conductive holder214when the ground shield202is coupled thereto.

The external ground pins352are offset with respect to the receptacle signal contacts outside of the envelope of the holder214. The external ground pins352are located to provide shielding between the receptacle signal contacts124of the contact module122and receptacle signal contacts124of an adjacent contact module122within the receptacle assembly102. For example, the external ground pins352are generally aligned with the interface between two adjacent contact modules122. The external ground pins352may be generally aligned with the plane of the main body330of the second ground shield202. Optionally, the external ground pins352may include a jogged section (not shown) that slightly shifts the external ground pins352out of the plane of the main body330, such as to align the external ground pins352with external ground pins of the adjacent contact module122.

In an exemplary embodiment, the holder members216,218include slots360,362, respectively, in the fronts thereof that receive the grounding beams302,332, respectively, therein when the ground shields200,202are coupled thereto. The projections308,338are received in the slots360,362and engage the holder members216,218to create an electrical connection with the holder members216,218. In an exemplary embodiment, the slots360,362are vertically offset with respect to the receptacle signal contacts124. When the grounding beams302,332are received in the slots360,362, the grounding beams302,332are vertically offset with respect to the receptacle signal contacts124. For example, the grounding beams302,332may be positioned above and/or below corresponding receptacle signal contacts124. In an exemplary embodiment, the grounding beams302are generally vertically aligned with the receptacle signal contacts124of the dielectric frame240and the grounding beams332are generally vertically aligned with the receptacle signal contacts124of the dielectric frame242. The grounding beams302,332provide electrical shielding between the receptacle signal contacts124in different rows.

In an exemplary embodiment, the holder members216,218include slots364,366(shown inFIG. 4), respectively, in the bottoms thereof that receive the internal ground pins320,350, respectively, therein when the ground shields200,202are coupled thereto. The projections354are received in the slots366and engage the holder member218to create an electrical connection with the holder member218. In an exemplary embodiment, the slots364,366are offset with respect to the receptacle signal contacts124. When the internal ground pins320,350are received in the slots364,366, the internal ground pins320,350are positioned between the receptacle signal contacts124. For example, the internal ground pins320,350may be positioned forward and/or rearward of corresponding receptacle signal contacts124. In an exemplary embodiment, the internal ground pins320are generally aligned (e.g. front-to-back) with the receptacle signal contacts124of the dielectric frame240and the internal ground pins350are generally aligned (e.g. front-to-back) with the receptacle signal contacts124of the dielectric frame242.

FIG. 3is an exploded view of the receptacle assembly102showing one of the contact modules122poised for loading into the front housing120.FIG. 3also illustrates a contact spacer370used to organize and/or hold the contact tails252and ground pins316,346(shown inFIG. 2). Only one contact module122is illustrated inFIG. 3, and it is realized that any number of contact modules122may be loaded into the front housing120during assembly of the receptacle assembly102.

During assembly of the contact module122, the dielectric frames240,242(shown inFIG. 2) are received in the corresponding holder members216,218. The holder members216,218are coupled together and generally surround the dielectric frames240,242. The dielectric frames240,242are aligned adjacent one another such that the receptacle signal contacts124are aligned with one another and define contact pairs390. Each contact pair390is configured to transmit differential signals through the contact module122. The receptacle signal contacts124within each contact pair390are arranged in rows that extend along row axes392. The receptacle signal contacts124within the dielectric frame240are arranged within a column along a column axis394. Similarly, the receptacle signal contacts124of the dielectric frame242are arranged in a column along a column axis396. In the illustrated embodiment, at the mating end128, the rows are oriented horizontally and the columns are oriented vertically, however it is noted that at the contact tails252, the columns, and thus the column axes394,396, as shown inFIG. 4, are oriented horizontally. Other orientations are possible in alternative embodiments.

The first and second ground shields200,202are coupled to the holder214to provide shielding for the receptacle signal contacts124. When assembled, the first ground shield200is positioned exterior of, and along, the first side wall222. The grounding beams302extend into the slots360and are generally aligned with the mating portions250along the column axis394. The grounding fingers303extend forward from the front226and are positioned outside of the receptacle signal contacts124. The grounding fingers303are generally aligned with the mating portions250along the row axes392. Optionally, the grounding fingers303may be offset (e.g. positioned below) with respect to the centerline of the mating portions250, however the grounding fingers303may still be horizontally aligned with a portion of the mating portions250(e.g. a bottom edge of the mating portions250). The first and second ground shields200,202are configured to be electrically connected to the header shields146when the receptacle assembly102is coupled to the header assembly104(both shown inFIG. 1).

The grounding beams302,332provide shielding for the receptacle signal contacts124in the dielectric frame240and the dielectric frame242, respectively. The grounding beams302,332are aligned with the contact pairs390along the column axis394and the column axis396. In an exemplary embodiment, one set of grounding beams302,332is provided below the lowermost contact pair390, another set of grounding beams302,332is provided above the uppermost contact pair390, and other sets of grounding beams302are provided between each of the contact pairs390. Each of the contact pairs390is thereby shielded both above and below its respective row axis392.

The grounding fingers303,333extend forward from the front226along the sides of the contact pairs390. The grounding fingers303,333are generally aligned with the contact pairs390along the row axes392. The grounding fingers303,333are vertically offset with respect to the grounding beams302,332. During use, the grounding fingers303,333are generally aligned horizontally with the contact pairs390while the grounding beams302,332are positioned vertically between the contact pairs390. The grounding fingers303,333are horizontally offset with respect to the grounding beams302,332. For example, the grounding beams302,332are generally aligned with the column axes394,396, while the grounding fingers303,333are offset horizontally outside of the column axes394,396.

The contact spacer370includes a base372having a plurality of openings374,375therethrough. The base372is manufactured from a dielectric material. The openings374are configured to receive corresponding contact tails252and the openings375are configured to receive ground pins316,346. The openings374,375are arranged in rows and columns that correspond to the positioning of the contact tails252and ground pins316,346. Openings375for the ground pins316,346tend to surround (e.g. forward, rearward, and both sides) the openings374for the contact tails252. The ground pins316,346are positioned all around the pairs of contact tails252. In an exemplary embodiment, a column of openings375for the ground pins316,346is arranged between each pair of columns of openings374for the contact tails252that receive the pair390of contacts associated with each contact module122. Openings375for the ground pins316,346are arranged between each pair of openings374for the contact tails252of a corresponding pair390of contacts. Other configurations of openings374,375are possible in alternative embodiments.

The contact spacer370holds the contact tails252and ground pins316,346at predetermined positions for mating with the circuit board106. The contact spacer370is coupled to all of the contact modules122after all of the contact modules122are received in the front housing120. The receptacle assembly102may then be mounted to the circuit board106as a unit.

FIG. 4is an enlarged view of a portion of the bottom of the receptacle assembly102with the contact spacer370(shown inFIG. 3) removed for clarity. Portions of two contact modules122are shown inFIG. 4. The ground shields200,202are coupled to the holders214. The ground pins316,346extend from the ground shields200,202into shielding positions around the contact pairs390. The internal ground pins320extend into the slots364. When positioned next to another contact module122, the external ground pins322are provided along the first side wall222generally aligned along the interface between the contact modules122. When positioned next to another contact module122, the external ground pins322are interspersed with the external ground pins352of the other contact module122. The internal ground pins350extend into the slots366. When positioned next to another contact module122, the external ground pins352are provided along the second side wall223generally aligned along the interface between the contact modules122. When positioned next to another contact module122, the external ground pins352are interspersed with the external ground pins322of the other contact module122.

The internal ground pins320,350are generally aligned with the contact tails252along the column axes394,396, respectively. The internal ground pins320,350are interspersed between each pair of contact tails252. The internal ground pins320,350are provided at distal ends376,378of tabs380,382that are bent or folded in from the main bodies300,330.

The external ground pins322,352are positioned between the columns of contact tails252. Optionally, the external ground pins322,352may be offset rearward and forward, respectively, of the row axes392such that the external ground pins322,352are not directly in line with the contact tails252, but rather are staggered slightly forward and rearward of the contact tails252. Having external ground pins322,352from both ground shields200,202between the contact modules122in essence doubles the number of ground pins between the contact tails252, thereby providing additional shielding for the receptacle signal contacts124. The positioning of the ground pins322,352may be selected to allow room for traces to be routed in the circuit board. In an exemplary embodiment, jogged sections326on the external ground pins322and corresponding jogged sections356on the external ground pins352position the external ground pins322,352in a single column by jogging the external ground pins322toward the adjacent contact module122and by jogging the external ground pins352toward the adjacent contact module122. The amount of jog may be selected to align the external ground pins322,352. Alternatively, the external ground pins352may not be jogged and may be arranged in two columns that are slightly offset.

FIG. 5is a partial sectional view of a portion of the electrical connector system100showing the receptacle assembly102mated to the header assembly104. The grounding electrical connection between the shield structure126and the header shields146is illustrated inFIG. 5. The first and second ground shields200,202(shown inFIG. 2) are electrically connected to corresponding header shields146.

The front housing120of the receptacle assembly102includes the signal contact openings132and the ground contact openings134. When the header assembly104and receptacle assembly102are mated, the header signal contacts144are mated to the receptacle signal contacts124within the signal contact openings132. The header shields146are received in the ground contact openings134. The grounding beams302,332engage and are electrically connected to corresponding header shields146within the ground contact openings134. The grounding beams302,332engage the center wall156of the C-shaped header shields146to make electrical connection therewith.

The grounding fingers303,333engage and are electrically connected to corresponding header shields146within the ground contact openings134. Optionally, the grounding fingers303,333and header shields146have approximately equal thicknesses such that the grounding fingers303,333and header shields146can both be received in the ground contact openings134. Optionally, the width of the ground contact openings134may be substantially equal to the thicknesses of the grounding fingers303,333and header shields146such that the grounding fingers303,333do not slip off of the edges160,162. The grounding fingers303,333engage the edges160,162of the C-shaped header shields146to make electrical connection therewith.

In an exemplary embodiment, the grounding beams302,332and the grounding fingers303,333are deflectable and are configured to be spring biased against the header shields146to ensure electrical connection with the header shields146. The bumps312,342on the grounding fingers303,333are upward facing and engage the bottom edges160,162, respectively, to ensure electrical connection between the ground shields200,202and the header shield146.

In an exemplary embodiment, the header shields146and the shield structure126provide 360° shielding for the receptacle signal contacts124. For example, the side wall154and the grounding fingers303both extend along first sides of the receptacle signal contacts124to provide shielding along such sides of the receptacle signal contacts124. The side wall158and the grounding fingers333both extend along second sides of the receptacle signal contacts124to provide shielding along such sides of the receptacle signal contacts124. The header shields146and grounding fingers303,333thus provide shielding between corresponding columns of the receptacle signal contacts124, such as between receptacle signal contacts124held within different contact modules122. The grounding beams302,332and the center wall156both extend along the receptacle signal contacts124. The center wall156and grounding beams302,332provide shielding between receptacle signal contacts124in different rows.

The shield structure126has multiple, redundant points of contact with each of the C-shaped header shields146. For example, four points of contact are defined by the grounding fingers303,333and the grounding beams302,332. The electrical performance of the electrical connector system100is enhanced with multiple ground contact points to the C-shaped header shield146, as compared to systems that have a single ground contact point.