The subject matter herein relates generally to electrical connectors that have signal contacts and ground shields that electrically shield the signal contacts from one another.
Communication systems exist today that utilize electrical connectors to transmit large amounts of data at high speeds. For example, in a backplane communication system, a backplane circuit board interconnects a plurality of daughter card assemblies. The backplane circuit board includes an array of header connectors that mate with corresponding receptacle connectors of the daughter card assemblies. The receptacle connectors are mounted to a daughter card of the corresponding daughter card assembly. The header and receptacle connectors include complementary arrays of electrical contacts. In some systems, the header connector includes signal contacts and ground shields that are positioned between, for example, pairs of the signal contacts. The receptacle connector includes signal contacts and corresponding ground contacts. During the mating operation, the signals contacts of the header and receptacle connectors engage one another to form signal pathways between the header and receptacle connectors. The ground contacts of the receptacle connector engage the ground shields of the header connector.
There has been a general demand to increase the density of signal contacts and increase the speeds at which data is transmitted through the communication systems. Consequently, it has been more challenging to maintain a baseline level of signal quality. For example, in some cases, the electrical energy that flows through each ground shield of the header connector may be reflected and resonate within the respective ground shield. The electrical energy may radiate from one ground shield and couple with nearby ground shields thereby causing electrical noise. Depending on the frequency of the crosstalk noise, the crosstalk noise can reduce signal quality.
Accordingly, there is a need for electrical connectors that reduce the electrical noise caused by separate ground shields.
In an embodiment, an electrical connector is provided that includes a connector housing having a front side that faces along a mating axis and contact passages that open to the front side. The contact passages are configured to receive corresponding ground shields of a system connector during a mating operation. The electrical connector also includes signal contacts that are coupled to the connector housing and configured to engage corresponding contacts of the system connector. The electrical connector also includes a grounding lattice that is held by the connector housing. The grounding lattice includes a support frame and lattice springs that are interconnected by the support frame. The support frame extends generally transverse to the mating axis. The lattice springs are positioned to engage the ground shields of the system connector as the ground shields are inserted into the corresponding contact passages of the connector housing.
In some embodiments, the connector housing has a loading side that is generally opposite the front side. The grounding lattice may be located within the connector housing between the front and loading sides. Optionally, the connector housing includes a cover portion and a base portion that are separable from each other. The cover portion may include the front side, wherein the grounding lattice is positioned between the cover and base portions.
In some embodiments, the contact passages form a two-dimensional passage array. The grounding lattice is configured to electrically ground a two-dimensional shield array of the ground shields when the electrical connector and the system connector are mated.
In an embodiment, a communication system is provided that includes a first electrical connector having a contact array including first signal contacts and ground shields that are positioned between the first signal contacts. The communication system also includes a second electrical connector having a connector housing with a front side that faces along a mating axis and contact passages that open to the front side. The second electrical connector also includes second signal contacts and a grounding lattice that is held by the connector housing. The grounding lattice extends generally transverse to the mating axis. The first signal contacts and the second signal contacts engage one another when the first and second electrical connectors are mated to establish signal pathways. The ground shields are received within the contact passages and shield the signal pathways from one another. The grounding lattice engages the ground shields to electrically common the ground shields. Optionally, the ground shields may be electrically commoned along two perpendicular axes.
In some embodiments, the ground shields include shield bodies that have respective body lengths measured along the mating axis. Each of the body lengths is measured between a leading edge and a trailing edge of the corresponding shield body. As one example, the grounding lattice may engage the shield bodies within a middle one-half (½) of the body length. However, the grounding lattice may engage the shield bodies at other locations.
In an embodiment, an electrical connector is provided that includes a connector housing having a front side and contact passages that open to the front side. The contact passages configured to receive corresponding ground shields of a system connector during a mating operation. The electrical connector also includes contact sub-assemblies having signal contacts and ground contacts. The signal contacts are configured to engage corresponding contacts of the system connector. The ground contacts are positioned within corresponding contact passages and configured to engage the corresponding ground shields during the mating operation. Each of the contact sub-assemblies includes a pair of the signal contacts and at least one of the ground contacts that is positioned adjacent to the pair of the signal contacts. The electrical connector also includes a grounding lattice held by the connector housing and extending generally parallel to the front side. The grounding lattice engages the corresponding ground shields within the corresponding contact passages when the system connector and the electrical connector are mated to electrically common the ground shields.
Embodiments set forth herein may include electrical connectors and communication systems having the electrical connectors. Although the illustrated embodiment includes electrical connectors that are used in high-speed communication systems, such as backplane or midplane communication systems, it should be understood that embodiments may be used in other communication systems or in other systems/devices that utilize electrical contacts. In the illustrated embodiment, the electrical connectors are referred to as header connectors and receptacle connectors. Embodiments, however, may include other types of electrical connectors. Accordingly, the inventive subject matter is not limited to the illustrated embodiment.
The circuit board assembly 102 includes a circuit board 110 having a first board side 112 and second board side 114. In some embodiments, the circuit board 110 may be a backplane circuit board, a midplane circuit board, or a motherboard. The circuit board assembly 102 includes a first header connector 116 mounted to and extending from the first board side 112 of the circuit board 110. The circuit board assembly 102 may also include a second header connector 118 mounted to and extending from the second board side 114 of the circuit board 110. The first and second header connectors 116, 118 include connector housings 117, 119, respectively. The first and second header connectors 116, 118 include contact arrays 123, 125, respectively, that each include electrical contacts 120, 122. The electrical contacts 120, 122 include signal contacts 120 and ground shields (or contacts) 122. In the illustrated embodiment, the contact arrays 123, 125 are two-dimensional arrays that extend along the first and second lateral axes 192, 193. The contact arrays 123, 125 form multiple columns (or rows).
The circuit board assembly 102 includes a plurality of signal paths (not shown) therethrough defined by the signal contacts 120 and conductive vias 170 (shown in
The ground shields 122 provide electrical shielding around corresponding signal contacts 120. In an exemplary embodiment, the signal contacts 120 are arranged in signal pairs 121 and are configured to convey differential signals. Each of the ground shields 122 may peripherally surround a corresponding signal pair 121. As shown, the ground shields 122 are C-shaped or U-shaped and cover the corresponding signal pair 121 along three sides. The ground shields 122 may be electrically coupled to one or more ground planes 127 of the circuit board 110. The ground planes 127 may be conductive layers that electrically common (or couple) the ground shields 122 to one another.
The connector housings 117, 119 couple to and hold the signal contacts 120 and the ground shields 122 in designated positions relative to each other. The connector housings 117, 119 may be manufactured from a dielectric material, such as a plastic material. Each of the connector housings 117, 119 includes a mounting wall 126 that is configured to be mounted to the circuit board 110 and shroud walls 128 that extend from the mounting wall 126.
The first connector system 104 includes a first circuit board 130 and a first receptacle connector 132 that is mounted to the first circuit board 130. The first receptacle connector 132 is configured to be coupled to the first header connector 116 of the circuit board assembly 102 during a mating operation. The first receptacle connector 132 has a front side 134 that is configured to be mated with the first header connector 116. The first receptacle connector 132 has a board interface 136 configured to be mated with the first circuit board 130. In an exemplary embodiment, the board interface 136 is oriented perpendicular to the front side 134. When the first receptacle connector 132 is coupled to the first header connector 116, the first circuit board 130 is oriented perpendicular to the circuit board 110.
The first receptacle connector 132 includes a connector housing or shroud 138. The connector housing 138 is configured to hold a plurality of contact modules 140 side-by-side. As shown, the contact modules 140 are held in a stacked configuration generally parallel to one another. In some embodiments, the contact modules 140 hold a plurality of signal conductors (not shown) that are electrically connected to the first circuit board 130. The signal conductors are configured to engage the signal contacts 120 of the first header connector 116 when the first header connector 116 and the first receptacle connector 132 are mated.
The second connector system 106 includes a second circuit board 150 and a second receptacle connector 152 coupled to the second circuit board 150. The second receptacle connector 152 is configured to be coupled to the second header connector 118 during a mating operation. The second receptacle connector 152 has a front side 154 configured to be mated with the second header connector 118. The second receptacle connector 152 has a board interface 156 configured to be mated with the second circuit board 150. In an exemplary embodiment, the board interface 156 is oriented perpendicular to the front side 154. When the second receptacle connector 152 is coupled to the second header connector 118, the second circuit board 150 is oriented perpendicular to the circuit board 110.
Similar to the first receptacle connector 132, the second receptacle connector 152 includes a connector housing or shroud 158 used to hold a plurality of contact modules 160. The contact modules 160 are held in a stacked configuration generally parallel to one another. The contact modules 160 hold a plurality of signal conductors 162 (shown in
In the illustrated embodiment, the first circuit board 130 is oriented generally horizontally. The contact modules 140 of the first receptacle connector 132 are oriented generally vertically. The second circuit board 150 is oriented generally vertically. The contact modules 160 of the second receptacle connector 152 are oriented generally horizontally. In such configurations, the first connector system 104 and the second connector system 106 may have an orthogonal orientation with respect to one another.
The first and second receptacle connectors 132, 152 may include grounding lattices 135, 155, respectively, held by the connector housings 138, 158, respectively. The grounding lattices 135, 155 are indicated by dashed lines in
The grounding lattices 135, 155 may be similar or identical to the grounding lattice 302 (shown in
The conductive vias 170 extend into the circuit board 110. In an exemplary embodiment, the conductive vias 170 extend entirely through the circuit board 110 between the first and second board sides 112, 114. In other embodiments, the conductive vias 170 extend only partially through the circuit board 110. The conductive vias 170 are configured to receive the signal contacts 120 of the first and second header connectors 116, 118. For example, the signal contacts 120 include compliant pins 172 that are configured to be loaded into corresponding conductive vias 170. The compliant pins 172 mechanically engage and electrically couple to the conductive vias 170. Likewise, at least some of the conductive vias 170 are configured to receive compliant pins 174 of the ground shields 122. The compliant pins 174 mechanically and electrically couple to the conductive vias 170. The conductive vias 170 that receive the compliant pins 174 may be electrically coupled to the ground planes 127.
The ground shields 122 are C-shaped and provide shielding on three sides of the signal pair 121. The ground shields 122 have a plurality of shield walls, such as three shield walls 176, 178, 180. The shield walls 176, 178, 180 may be integrally formed or alternatively, may be separate pieces. The compliant pins 174 extend from each of the shield walls 176, 178, 180 to electrically connect the shield walls 176, 178, 180 to the circuit board 110. The shield wall 178 defines a center wall or top wall of the ground shield 122. The shield walls 176, 180 define side walls that extend from the shield wall 178. The shield walls 176, 180 may be generally perpendicular to the shield wall 178. The grounding lattice 155 (
When the second receptacle connector 152 is fully assembled, the signal conductors 162 and ground contacts 206 of the contact modules 160 are coupled to the connector housing 158. The coupling may be direct, such that the connector housing 158 directly engages the ground contacts 206 and/or the signal conductors 162. Alternatively, the connector housing 158 may indirectly couple to the ground contacts 206 and/or the signal conductors 162. For example, the ground contacts 206 and/or the signal conductors 162 may be held by the contact modules 160, which are secured to the connector housing 158.
The contact module 160 is coupled to the connector housing 158 such that the signal conductors 162 are received in corresponding signal passages 202. Optionally, a single signal conductor 162 is received in each signal passage 202. The signal passages 202 are also configured to receive corresponding signal contacts 120 (
The connector housing 158 is manufactured from a dielectric material, such as a plastic material, and may provide separation between the signal passages 202 and the ground passages 204. The ground passages 204 are C-shaped in the illustrated embodiment to receive the C-shaped ground shields 122 (
The contact module 160 includes a shield assembly 220 that provides shielding for the signal conductors 162. In an exemplary embodiment, the shield assembly 220 is located between pairs of the signal conductors 162 to provide shielding between each of the pairs of signal conductors 162. The shield assembly 220 includes a side shell 222 and one or more ground clips 224, 225 that are coupled to the side shell 222. The side shell 222 has a main body 226 that is generally planar and extends along a first side 236 of the dielectric frame 212. The side shell 222 includes ground tabs 238 extending (e.g. downward) from the main body 226. The ground tabs 238 are configured to be received in corresponding trenches 250 of the dielectric frame 212 such that the ground tabs 238 are located between adjacent pairs of signal conductors 162. The ground tabs 238 and side shell 222 together define a C-shaped shield structure that surrounds each pair of signal conductors 162 on three sides.
The ground clips 224, 225 are mounted to a front of the side shell 222. The ground clips 224, 225 are similar to one another and only the ground clip 224 is described in detail below. The ground clip 224 includes a base 240 and ground contacts 206 extending from a front edge 244 of the base 240. The ground contacts 206 are configured to extend into the ground passages 204 (
In the illustrated embodiment, the ground clip 224 includes a central ground contact 206A and a pair of side ground contacts 206B, 206C. The central ground contacts 206A are configured to be positioned above the pairs of signal conductors 162. The side ground contacts 206B, 206C are configured to be positioned between pairs of the signal conductors 162 that are held by the same dielectric frame 212. The side ground contacts 206B, 206C provide shielding along sides of the signal contacts 215 of the signal conductors 162. The ground contacts 206A, 206B, 206C provide shielding on three sides of each pair of signal conductors 162.
In an exemplary embodiment, the ground clips 224, 225 are mounted to the side shell 222 with the ground clip 225 stacked on the ground clip 224. The ground contacts 206 of the ground clip 225 are laterally offset from the ground contacts 206 of the ground clip 204 such that the ground contacts 206 of both ground clips are interleaved when the ground clips 224, 225 are stacked. The ground contacts 206 of each ground clip 224, 225 provide shielding around successive, alternating pairs of signal conductors 162. In an exemplary embodiment, the ground clips 224, 225 are stamped and formed.
The shield assembly 220 may include ground pins 246 extending from a bottom 248 of the side shell 222. The ground pins 246 may be compliant pins. The ground pins 246 are configured to be received in corresponding conductive vias in the second circuit board 150. Optionally, the ground pins 246 may be integrally formed with the side shell 222. In an alternative embodiment, a separate clip or bar may be coupled to the bottom 248 of the side shell 222 that includes the ground pins 246.
The first and second links 310, 312 form a grid or web-like pattern that includes a plurality of openings 316 therethrough. Each opening 316 is sized and shaped to permit a ground shield 410 (shown in
The grounding lattice 302 may be stamped and formed from a conductive material, such as sheet metal. Alternatively, the grounding lattice 302 may include a dielectric frame (e.g., plastic body) that is plated with a conductive material. For example, the grounding lattice 302 may be 3D-printed using a conductive material or 3D-printed using a dielectric frame that is subsequently plated with conductive material. The support frame 304 is substantially planar and extends parallel to a plane defined by the first and second lateral axes 392, 393. The support frame 304 extends transverse or orthogonal to the mating axis 391. In alternative embodiments, the support frame 304 is not planar. For example, the first and second links 310, 312 may include segments that extend parallel to the mating axis 391. The first and second links 310, 312 may also have curved contours in other embodiments.
In the illustrated embodiment, the side lattice springs 306 and the wall lattice springs 308 extend away from the support frame 304 in a mating direction 315 that is generally parallel to the mating axis 391. In other embodiments, one or more of the side lattice springs 306 and/or one or more of the wall lattice springs 308 may extend in an opposite direction along the mating axis 391. Each wall lattice spring 308 is approximately located at a midpoint of the corresponding link 310. In alternative embodiments, the wall lattice springs 308 may have different locations. The side lattice springs 306 may also have different locations than those shown in
The side lattice springs 306A, 306B may have similar configurations as the wall lattice springs 308. The side lattice springs 306A, 306B include respective elongated bodies 307 that project in opposite directions from a common first link 310. The common first link 310 includes opposite edges 326, 328. The side lattice springs 306A, 306B extend in opposite directions away from the edges 326, 328, respectively. The side lattice springs 306A, 306B are configured to engage different ground shields 410 that are separated by the common first link 310.
The elongated bodies 307 of the corresponding side lattice springs 306A, 306B may have a similar curved contour as the elongated body 309 of the wall lattice spring 308 and include respective inflections areas 330. The inflection areas 330 of the side lattice springs 306A, 306B generally face in opposite directions. Like the inflection area 324, the inflection areas 330 are configured to be positioned within paths of the corresponding ground shields 410 such that the ground shields 410 engage the respective side lattice springs 306A, 306B. Although the side lattice springs 306A, 306B are shown in
The receptacle connector 340 includes a connector housing 342 having a front side 344 that includes contact passages 346, 348 that open to the front side 344. The front side 344 extends generally parallel to the first and second lateral axes 392, 393 and perpendicular to the mating axis 391. The contact passages 346, 348 are hereinafter referred to as ground passages 346 and signal passages 348. It should be understood that embodiments may include various combinations or groupings of signal and ground passages. For example, in the illustrated embodiment, a single ground passage 346 partially surrounds a pair of the signal passages 348 to form a passage group 350. The signal passages 348 of a passage group 350 are defined within a common dielectric block 362 of the connector housing 342. The ground passage 346 of the passage group 350 is defined between the dielectric block 362 and housing walls 366, 374. The housing walls 366 extend along the first lateral axis 392, and the housing wall 374 extends along the second lateral axis 393. The ground passages 346 and the signal passages 348 (or the passage groups 350) form a two-dimensional passage array 351. In alternative embodiments, each passage group 350 may include more than one ground passage and/or only one signal passage.
It should also be understood that embodiments may have signal and ground passages that have different shapes than those shown in
The receptacle connector 340 includes contact sub-assemblies 352. Each of the contact sub-assemblies 352 may include ground contacts 354A, 354B, 354C and signal contacts 356A, 356B. The ground contact 354A may be termed the central ground contact, and the ground contacts 354B, 354C may be termed the side ground contacts. The ground contacts 354A-354C are positioned within the same ground passage 346, but the signal contacts 356A, 356B are positioned in different signal passages 348. The ground contacts 354A-354C may be similar to the ground contacts 206A-206C shown in
Each of the signal passages 348 is shaped to receive a corresponding signal contact 432 (shown in
The ground passage 346 is shaped to receive a corresponding ground shield 410 (shown in
As shown in
Also shown in
The ground contact 354C of the contact module 370 and the ground contact 354B of the contact module 372 extend into a cavity portion 376 of the contact cavity 364 between the dielectric blocks 362A, 362B. The ground contact 354C of the contact module 370 and the ground contact 354B of the contact module 372 are aligned with the ground passages 346A, 346B, respectively. The ground contacts 354B and 354C may be electrically coupled to shield assemblies (not shown) of the contact modules 372, 370, respectively. Such shield assemblies may be similar to the shield assembly 220 (
When the separate ground shields 410 (
The system connector 402 includes a connector housing 404 having a mounting wall 405 that interfaces with the circuit board 406. The connector housing 404 may be similar or identical to the connector housings 117, 119 (
The system connector 402 also includes a two-dimensional shield array 380 of the ground shields 410. Like the contact array 125 (
The shield body 412 includes the shield walls 421 (
Each of the shield bodies 412 has a body length 430 that is measured between the trailing edge 416 and the leading edge 414 of the corresponding shield body 412 along the mating axis 391. The shield tail 418 has a cross-sectional area taken transverse to the mating axis 391 that is different than a cross-sectional area of the shield body 412. In such embodiments, the change in cross-sectional area may form a reflection or choke region 434 within the ground shield 410.
During operation of the communication system 400, electrical energy may be reflected within the shield body 412 proximate to the reflection region 434. More specifically, as the ground shield 410 transitions between the trailing edge 416 and the shield tail 418, the reduction in cross-sectional area may cause the electrical energy to reflect within the shield body 412. Without the grounding lattice 302, the electrical energy may resonate at a frequency and magnitude that is based, in part, on the body length 430. Under certain circumstances, such electrical resonance may negatively affect the signal integrity of the signals propagating through the signal contacts 432 (
The electrical performance may be based, in part, on longitudinal locations at which the grounding lattice 302 engages the ground shields 410. For example, the wall lattice springs 308 engage the ground shields 410 at contact points X1. The side lattice lattice springs 306A, 306B (
In some embodiments, the contact points X1, X2 are within a middle one-half (½) of the body length 430 (indicated by Z1). More specifically, if the body length 430 was separated into quarters, the middle one-half Z1 would represent a portion of the body length 430 that includes the second and third quarters of the body length 430. In other words, the middle one-half Z1 begins at an end of a first quarter of the body length 430 and ends at a beginning of the fourth quarter of the body length 430. In particular embodiments, the contact points X1, X2 are within a middle one-third (⅓) of the body length 430 (indicated by Z2). In more particular embodiments, the contact points X1, X2 are located at about the midpoint of the body length 430. However, the grounding lattice 302 may engage the ground shields 410 at other longitudinal locations with respect to the body length 430, such as proximate to the mounting wall 405 or proximate to a loading side 382 of the connector housing 342.
Accordingly, the grounding lattice 302 may electrically common the ground shields 410 of the two-dimensional shield array 380. The grounding lattice 302 may effectively change the frequency at which the electrical energy resonates within the ground shields 410 such that the electrical noise generated by the electrical energy does not significantly degrade signal quality of the communication system 400.
The connector housing 450 is oriented with respect to a mating axis 491 and first and second lateral axes 492, 493. In the illustrated embodiment, the cover portion 452 includes a front side 456 of the connector housing 450 and a back side 458 that face in opposite directions along the mating axis 491. The cover portion 452 includes contact passages 480, 482, which may be termed signal passages 480 and ground passages 482. The signal and ground passages 480, 482 extend between the front side 456 and the back side 458. The signal and ground passages 480, 482 open to the front side 456 and open to the back side 458.
The base portion 454 includes a cover side 460 and a loading side 462 that face in opposite directions along the mating axis 491. The base portion 454 includes contact cavities 464 that extend between the cover and loading sides 460, 462. The contact cavities 464 are configured to align with the signal and ground passages 480, 482 and receive signal contacts (not shown) from contact modules (not shown). For instance, the contact cavities 464 may be configured to receive the signal contacts 215 (
The cover portion 452 and the base portion 454 may be shaped to include complementary features, such as projections and cavities, that engage each other through a frictional engagement (or an interference fit). For example, the base portion 454 includes recesses 476 that open to the cover side 460. The recesses 476 may be sized and shaped to receive corresponding elements of the grounding lattice 302 and/or corresponding elements of the cover portion 452. Alternatively or in addition to the frictional engagement, an adhesive may be applied to the cover side 460 of the base portion 454 and/or the back side 458 of the cover portion 452 to secure the cover portion 452 to the base portion 454. When the cover portion 452 is operably coupled to the base portion 454, each of the signal and ground passages 480, 482 may align with one or more of the contact cavities 464.
Also shown in
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the various embodiments without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The patentable scope should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
As used in the description, the phrase “in an exemplary embodiment” and the like means that the described embodiment is just one example. The phrase is not intended to limit the inventive subject matter to that embodiment. Other embodiments of the inventive subject matter may not include the recited feature or structure. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112(f), unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
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8398431 | Whiteman, Jr. | Mar 2013 | B1 |
8419472 | Swanger | Apr 2013 | B1 |
8465323 | Jeon | Jun 2013 | B2 |
8905786 | Davis | Dec 2014 | B2 |
20130178107 | Costello | Jul 2013 | A1 |
20140080331 | Jeon | Mar 2014 | A1 |
Number | Date | Country | |
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20160072231 A1 | Mar 2016 | US |