[0001] The invention relates to an electrical connector having grounding features to improve
electrical performance.
[0002] To meet digital communication demands, higher data throughput in smaller spaces is
often desired for communication systems and equipment. Electrical connectors that
interconnect circuit boards and other electrical components should therefore handle
high signal speeds at large contact densities. One application environment that uses
such electrical connectors is in high speed, differential electrical connectors, such
as those common in the telecommunications or computing environments. In a traditional
approach, two circuit boards are interconnected to each other in a backplane and a
daughter card configuration using electrical connectors mounted to each circuit board.
[0003] At least one problem area is the interface between electrical components, such as
between two electrical connectors. In some cases, the electrical connectors include
conductive housings that function as shields for the electrical connectors. When the
electrical connectors are mated together, the housings are also electrically coupled
thereby establishing a return path between the electrical connectors. However, gaps
along the interface can occur due to, for example, manufacturing tolerances of the
electrical connectors or unwanted particles (e.g., dirt or dust) between the electrical
connectors. These gaps can negatively affect the electrical performance of the connector
assembly. The interface between an electrical connector and a circuit board may also
have gaps that negatively affect the electrical performance of the assembly.
[0004] There is a need for an electrical connector that can create a reliable interconnection
between two electrical components along an interface.
[0005] This problem is solved by an electrical connector according to claim 1.
[0006] According to the invention, an electrical connector comprises a connector body having
a mounting side and an array of signal contacts disposed along the mounting side.
The array of signal contacts has gaps formed between adjacent signal contacts of the
array. A grounding matrix extends along the mounting side. The grounding matrix includes
a plurality of ground contacts that are interconnected in a web-like manner to define
a plurality of openings. The signal contacts of the electrical connector extend through
the openings, and the ground contacts are electrically coupled to the electrical connector.
The grounding matrix includes attachment features that directly engage and couple
to the electrical connector to hold the grounding matrix in a designated position
along the mounting side.
[0007] According to another aspect, a circuit board assembly comprises an electrical connector
comprising a connector body having a mounting side and an array of signal contacts
disposed along the mounting side. The array of signal contacts has gaps formed between
adjacent signal contacts of the array. A circuit board having an engagement side includes
signal vias and ground vias. A grounding matrix is positioned between the engagement
side and the mounting side. The grounding matrix includes a plurality of ground contacts
that are interconnected in a web-like manner to define a plurality of openings. The
signal contacts of the electrical connector extend through the openings to engage
the signal vias, and the ground contacts electrically couple the ground vias of the
circuit board to a ground pathway through the electrical connector.
[0008] The invention will now be described by way of example with reference to the accompanying
drawings wherein:
Figure 1 illustrates a circuit board assembly formed in accordance with one embodiment
that includes grounding features.
Figure 2 is a perspective view of an electrical connector formed in accordance with
one embodiment and a grounding matrix.
Figure 3 is a representative view that illustrates an arrangement of terminals that
may be used with the electrical connector of Figure 2 and contact points that may
occur in the connector assembly of Figure 1.
Figure 4 is an enlarged perspective view of a portion of the grounding matrix that
may be used with the electrical connector of Figure 2.
Figure 5 is an isolated view of an exemplary embodiment of a ground contact that may
be used with the grounding matrix.
Figure 6 is a side view of the electrical connector having the grounding matrix positioned
within an interwoven reception region.
Figure 7 is an enlarged perspective view showing the grounding matrix in greater detail.
Figure 8 is a perspective view of a communication system in accordance with an embodiment.
Figure 9 illustrates a perspective view of a grounding matrix formed in accordance
with one embodiment.
Figure 10 is a bottom perspective view of a receptacle connector having the grounding
matrix of Figure 9 positioned along a mounting side of the receptacle connector.
Figure 11 is a top perspective view of a circuit board assembly that may be used with
the communication system of Figure 8.
Figure 12 is an enlarged view of a circuit board that may be used with the circuit
board assembly of Figure 11.
Figure 13 is a side cross-section of the receptacle connector of Figure 10 mounted
to the circuit board of Figure 11.
Figure 14 is a bottom perspective view of a header connector having a grounding matrix
positioned along a mounting side of the header connector.
Figure 15 is a plan view of a circuit board that illustrates an arrangement of signal
vias, ground vias, and contact areas in greater detail.
[0009] Figure 1 illustrates an electrical connector assembly 100 formed in accordance with
an exemplary embodiment. The connector assembly 100 includes first and second electrical
connectors 102, 104 and a grounding matrix 106 held by the electrical connector 102.
In other embodiments, the electrical connector 104 may hold the grounding matrix 106.
The electrical connectors 102, 104 are configured to engage each other and establish
an electrical connection therebetween during a mating operation. The first electrical
connector 102 may be referred to as a header connector of a backplane system, and
the second electrical connector 104 may be referred to as a receptacle connector of
the backplane system. However, it is understood that embodiments described herein
may be used in various applications and are not limited to backplane systems. As shown,
the connector assembly 100 is oriented with respect to mutually perpendicular axes
191-193 including a mating axis 191 and lateral axes 192, 193.
[0010] The electrical connector 102 has a mounting side 110 and an engagement side 112,
and the electrical connector 104 also has a mounting side 114 and an engagement side
116. In the illustrated embodiment, the mounting and engagement sides 110, 112 face
in opposite directions along the mating axis 191, and the mounting and engagement
sides 114, 116 also face in opposite directions. As such, the electrical connectors
102, 104 may be characterized as vertical connectors. However, in alternative embodiments,
the electrical connectors 102 and 104 may be right-angle connectors in which the respective
mounting and engagement sides face in perpendicular directions with respect to each
other. The mounting sides 110, 114 are configured to engage respective electrical
components, such as circuit boards (not shown).
[0011] The electrical connector 102 includes a connector body or housing 118, and the electrical
connector 104 includes a connector body 120. The connector bodies 118, 120 comprise
conductive material (e.g., metal, a mold with conductive particles, and the like).
The connector bodies 118, 120 may form a return path when the electrical connectors
102, 104 are mated. The electrical connector 102 includes electrical terminals 122
that are held by the connector body 118 in an array. The electrical connector 104
also includes electrical terminals (not shown). The electrical terminals of the electrical
connector 104 may also be referred to as mating terminals. In an exemplary embodiment,
the electrical connector 102 has a body-receiving cavity 126 that opens to the engagement
side 112. The receiving cavity 126 is sized and shaped to receive the connector body
120.
[0012] During the mating operation, the receiving cavity 126 receives the engagement side
116. The electrical terminals 122 and the electrical terminals of the electrical connector
104 engage each other and establish the electrical connection. When the electrical
connectors 102 and the electrical terminals of the electrical connector 104 are engaged,
the grounding matrix 106 operates to electrically couple the connector bodies 118,
120 along a mating interface. In alternative embodiments, the engagement side 116
includes a receiving cavity and the engagement side 112 is configured to be received
by the receiving cavity of the engagement side 116.
[0013] When the electrical connectors 102, 104 are mated, the electrical connectors 102,
104 are moved relatively toward each other along a mating direction M
1 that extends substantially parallel to the mating axis 191. The mating direction
M
1 is indicated as being bi-directional because the electrical connector 102 may be
moved toward the electrical connector 104 or vice versa. Furthermore, both of the
electrical connectors 102, 104 can be moved toward each other at the same time. In
an exemplary embodiment, the electrical terminals 122 and the electrical terminals
of the electrical connector 104 slidably engage each other during the mating operation.
[0014] In an exemplary embodiment, the electrical connector 102 is a backplane connector
and the electrical connector 104 is a daughter card connector. However, in alternative
embodiments, the electrical connector 102 may be a daughter card connector and the
electrical connector 104 may be a backplane connector. While the connector assembly
100 is described herein with reference to a backplane connector and a daughter card
connector, it is realized that the subject matter herein may be utilized with different
types of electrical connectors other than a backplane connector or a daughter card
connector. The backplane connector and the daughter card connector are merely illustrative
of an exemplary embodiment of the connector assembly 100. In particular embodiments,
the connector assembly 100 transmits high-speed data signals. For example, the data
signals may be transmitted at speeds greater than or equal to 15 Gbps. In more particular
embodiments, the data signals may be transmitted at speeds greater than or equal to
20 Gbps or greater than or equal to 25 Gbps. However, in other embodiments, the connector
assembly 100 may transmit data signals at slower speeds.
[0015] Figure 2 is a perspective view of the electrical connector 102 and the grounding
matrix 106. In an exemplary embodiment, the connector body 118 includes housing walls
128-131 and a conductive surface 132 that define the receiving cavity 126. The housing
walls 128-131 project from the conductive surface 132 along the mating axis 191. The
conductive surface 132 defines a depth D
1 of the receiving cavity 126 measured from edges of the housing walls 128-131. As
shown, the receiving cavity 126 not only opens to the engagement side 112 in a direction
along the mating axis 191 but also opens to the exterior of the electrical connector
102 in directions along the lateral axes 192, 193. More specifically, the housing
walls 128-131 may have openings 138-141 therebetween that provide access to the receiving
cavity 126 from the exterior. In some embodiments, one or more of the openings 138-141
complement features of the electrical connector 104 such that the features slide through
the openings 138-141.
[0016] In an exemplary embodiment, the electrical terminals 122 constitute contact towers
that project away from the conductive surface 132 along the mating axis. The electrical
terminals 122 may also constitute socket contacts that have respective contact cavities
134 that are configured to receive the electrical terminals of the electrical connector
104. The electrical terminals 122 extend a height H from the conductive surface 132.
The height H may be substantially equal to the depth D
1. As shown, the electrical terminals 122 have substantially equal heights H with respect
to one another. In alternative embodiments, the heights H may be different.
[0017] Figure 3 shows an arrangement of the electrical terminals 122 located on the conductive
surface 132 (Figure 2) according to an exemplary embodiment. As shown, the electrical
terminals 122 are spaced apart from one another and positioned in an array along the
conductive surface 132. In the illustrated embodiment, the electrical terminals 122
are arranged in rows and columns in the array. However, the array is not required
to have linear rows or columns. Instead, the electrical terminals 122 can be located
in any predetermined arrangement that is desired.
[0018] In the illustrated embodiment, adjacent terminals 122 may be separated by gaps 142
and by gaps 144. The gaps 142 extend generally along the lateral axis 192 (Figure
1), and the gaps 144 extend generally along the lateral axis 193 (Figure 1). Two terminals
can be adjacent if no other terminal is located therebetween. As such, adjacent terminals
122 may also be separated by gaps 143 that extend diagonally with respect to the lateral
axes 192, 193. The gaps 142-144 may collectively form an interwoven reception region
146 that extends along the conductive surface 132 between the electrical terminals
122.
[0019] The reception region 146 may include first and second paths 148, 150 in which each
of the first and second paths 148, 150 extends through a plurality of the gaps that
separate the electrical terminals 122. The paths 148, 150 may extend continuously
therethrough without being interrupted by walls or other projections extending from
the conductive surface 132. As used herein, a reception region is interwoven when
at least two of the paths extend along a plurality of corresponding terminals and
intersect each other. For example, the reception region 146 includes the first path
148 that extends along corresponding terminals 122 through the gaps 142, 143 and also
includes the second path 150 that extends along corresponding terminals 122 through
the gaps 144, 143. Each of the first and second paths 148, 150 extends along a series
of terminals 122.
[0020] In an exemplary embodiment, the first path 148 extends parallel to the lateral axis
193, and the second path 150 extends parallel to the lateral axis 192 such that the
paths 148, 150 intersect each other in a perpendicular manner. Also in an exemplary
embodiment, the reception region 146 may include a plurality of first paths 148 and
a plurality of second paths 150 that intersect one another. In the embodiment shown
in Figure 3, the paths 148, 150 are substantially linear and perpendicular to each
other. However, in alternative paths, the paths 148, 150 may be non-linear and/or
may not extend perpendicular to each other.
[0021] As will be described in greater detail below, the solid dots 184 and the hollow dots
186 shown in Figure 3 represent contact points where the grounding matrix 106 engages
the electrical connectors 102, 104 (Figure 1), respectively.
[0022] Returning to Figure 2, in some embodiments, the grounding matrix 106 may be positioned
within the receiving cavity 126 along the conductive surface 132. As shown, the grounding
matrix 106 can have a substantially planar body or frame 136 that includes ground
contacts 152 and linkages 154, 155 that interconnect the ground contacts 152 in a
web-like manner. The ground contacts 152 and the linkages 154, 155 may form openings
156. When the grounding matrix 106 is positioned within the reception region 146,
the ground contacts 152 and linkages 154 may be located in at least some of the gaps
142, 144 (Figure 3) and paths 148, 150 (Figure 3). The electrical terminals 122 may
advance or extend through the openings 156.
[0023] In an exemplary embodiment, the grounding matrix 106 is stamped-and-formed from a
layer of sheet material. The grounding matrix 106 may be conductive throughout. However,
the grounding matrix 106 can be formed in different manners in other embodiments.
For example, in one alternative embodiment, the grounding matrix may include an organizer
that holds separate ground contacts. The organizer may include the linkages.
[0024] As shown, the grounding matrix 106 may include edge members 160 along an outer perimeter
of the grounding matrix 106. In one embodiment, the edge members 160 can be outwardly
projecting tabs as shown in Figure 2. The housing walls 128-131 may include interior
slots or grooves 158 that are configured to receive the edge members 160. When the
grounding matrix 106 is deposited into the reception region 146, the edge members
160 frictionally engage the slots 158. In some embodiments, the grounding matrix 106
is floatably coupled to the electrical connector 102 such that the grounding matrix
106 is movable with respect to the connector body 118. For example, the grounding
matrix 106 can be at least floatable along the mating axis 191 toward and away from
the conductive surface 132.
[0025] Figure 4 is an enlarged perspective view of a portion of the grounding matrix 106
showing the ground contacts 152 and the linkages 154, 155 in greater detail. The linkages
include inner linkages 154, end linkages 155A, and side linkages 155B. The end and
side linkages 155A, 155B define a perimeter of the grounding matrix 106. As shown,
the inner linkages 154 join adjacent ground contacts 152A and 152B. Thus, the inner
linkages 154 may be characterized as inter-contact linkages. The inner linkages 154
have a linkage body 162 with contoured edges 164. The body 162 is sized and shaped
to be positioned within a corresponding gap 144 (Figure 3) between adjacent terminals
122 (Figure 1). The edges 164 may be shaped to extend along an exterior surface of
the corresponding terminal 122. In some embodiments, the inner linkages 154 may prevent
movement of the grounding matrix 106 in a direction along a plane defined by the lateral
axes 192, 193 (Figure 1). In some embodiments, the inner linkages 154 may also improve
the shielding abilities of the connector assembly 100 (Figure 1).
[0026] As shown in Figure 4, the end linkage 155A joins adjacent ground contacts 152C and
152D. The side linkages 155B also include the edge members 160 extending outward therefrom.
In an exemplary embodiment, the end and side linkages 155A, 155B surround the ground
contacts 152. The end linkages 155A may also have contoured edges 166 that are configured
to extend along an exterior surface of the corresponding terminal 122.
[0027] Figure 5 is an isolated view of an exemplary embodiment of the ground contact 152.
Optionally, ground contacts described herein may include one or more flex portions
that extend away from or toward the conductive surface 132 (Figure 2). For example,
the ground contact 152 shown in Figure 5 has first and second flex portions 170, 172
and a contact base 175 that joins the flex portions 170, 172. The contact base 175
may be located within and extend along a contact plane P. The contact plane P may
extend parallel to a plane defined by the lateral axes 192, 193 (Figure 1). The flex
portions 170, 172 extend from the contact base 175 in opposite directions away from
each other to respective distal ends 171, 173. The flex portions 170, 172 also extend
away from the contact plane P. In the illustrated embodiment, the flex portions 170,
172 curve or curl in the same direction away from the contact plane P. As such, the
ground contact 152 may be substantially C-shaped or cup-shaped.
[0028] However, in other embodiments, the flex portions 170, 172 may have different shapes.
For example, the ground contact 152 may have an overall V-shape or the ground contact
152 may have no curve and extend in a linear manner. One of the flex portions may
extend in one direction away from the contact plane P, and the other flex portion
may extend in an opposite direction away from the contact plane P. Also, in alternative
embodiments, the grounding matrix 106 may not include the flex portions 170, 172.
In such embodiments, the grounding matrix 106 may include only linkages, such as the
inner linkages 154 and the end and side linkages 155A, 155B.
[0029] Returning to Figure 4, the ground contacts 152 may have different features or characteristics
with respect to one another. For example, the grounding matrix 106 may include different
ground contacts 152A-D. The ground contacts 152A include flex portions 170A, 172A
that extend toward the conductive surface 132 when the grounding matrix 106 is properly
positioned. The ground contacts 152B include flex portions 170B, 172B that extend
away from the conductive surface 132. The ground contacts 152C and 152D each include
a single flex portion 174, 176, respectively. The flex portions 174, 176 extend toward
and away from the conductive surface 132, respectively.
[0030] Figure 6 is a side view of the electrical connector 102 having the grounding matrix
106 positioned within the reception region 146, and Figure 7 is an enlarged perspective
view showing the grounding matrix 106 and the conductive surface 132 in greater detail.
As shown in Figure 6, the connector body 118 has a pair of channels 180, 182 that
extend through the connector body 118. The channels 180, 182 may be defined between
the conductive surface 132 and the housing walls 128-131. The channels 180, 182 are
configured to receive corresponding edge members 160 when the grounding matrix 106
is positioned within the reception region 146. During insertion of the grounding matrix
106 into the reception region 146, the edge members 160 may be partially deflected
by the housing walls 128-131. The edge members 160 may resile back into a non-deflected
position after entering the channels 180, 182, and clearing the housing walls 128-131.
[0031] With respect to Figures 6 and 7, the ground contacts 152A (Figure 7), 152C (Figure
6) engage the conductive surface 132 and the ground contacts 15213 (Figure 7), 152D
(Figure 6) extend away from the conductive surface 132. A plurality of the ground
contacts 152 are located adjacent to one or more of the electrical terminals 122,
and a plurality of the ground contacts 152 are located between two terminals 122.
During the mating operation, the ground contacts 152A, 152C are configured to initially
engage the conductive surface 132 and the ground contacts 152B, 152D are configured
to initially engage a corresponding conductive surface (not shown) of the mating connector
104 (Figure 1). Accordingly, the grounding matrix 106 engages each of the conductive
surfaces thereby establishing an electrical connection between the connector bodies
118, 120 (Figure 1).
[0032] In an exemplary embodiment, the grounding matrix 106 engages the connector body 120
at a plurality of contact points 184 (shown as solid dots in Figure 3) where the flex
portions 170B, 172B (Figure 7) contact the conductive surface (not shown) of the electrical
connector 104 (Figure 1). The grounding matrix 106 also engages the connector body
118 at a plurality of contact points 186 (shown as hollow dots in Figure 3) where
the flex portions 170A, 172A (Figure 7) contact the conductive surface 132. In particular
embodiments, the ground contacts 152A and 152B alternate in the array such that for
each ground contact 152A that engages the conductive surface 132, the adjacent ground
contacts 152B engage the conductive surface (not shown) of the electrical connector
104 and for each ground contact 152B that engages the conductive surface of the electrical
connector 104, the adjacent ground contacts 152A engage the conductive surface 132.
[0033] The inner linkages 154, the end linkages 155A, the side linkages 155B, and the ground
contacts 152 are part of the same stamped-and-formed sheet material. However, in alternative
embodiments, the ground contacts 152 may be indirectly coupled to each other through,
e.g., an organizer or interposer. For instance, the organizer could include a planar
dielectric body having holes configured to receive one or more ground contacts 152
and openings configured to receive the electrical terminals 122. In other embodiments,
the ground contacts 152 may be entirely independent from each other such that each
ground contact 152 is separately positioned within the reception region 146.
[0034] Figure 8 illustrates a communication system 300 that includes a circuit board assembly
302 and a circuit board assembly 304 that are configured to engage each other during
a mating operation. The communication system 300 is oriented with respect to mutually
perpendicular axes 391-393, including a mating axis 391 and lateral axes 392, 393.
As shown, the circuit board assembly 302 includes an electrical connector 306 (hereinafter
referred to as a receptacle connector 306), a circuit board 308, and a grounding matrix
310. The circuit board 308 includes a leading edge 312 and opposite first and second
sides 314, 315. The first side 314 is hereinafter referred to as the engagement side
314. The receptacle connector 306 is mounted to the engagement side 314 along the
leading edge 312.
[0035] Also shown, the circuit board assembly 304 includes a header connector 316, a circuit
board 318, and a grounding matrix 320. The circuit board 318 has opposite first and
second sides 322, 323. The first side 322 is hereinafter referred to as the engagement
side 322. Although not shown in Figure 8, the circuit board assembly 304 also includes
a grounding matrix 321 (shown in Figure 14) between the header connector 316 and the
circuit board 318.
[0036] The grounding matrix 310 is located along a mounting interface 327 between the circuit
board 308 and the receptacle connector 306. Likewise, the grounding matrix 321 is
located along a mounting interface 326 between the circuit board 318 and the header
connector 316. When the receptacle and header connectors 306, 316 are engaged, the
grounding matrix 320 may be located along a mating interface (not shown) between the
receptacle and header connectors 306, 316.
[0037] As set forth herein, the grounding matrices 310, 320, and 321 are configured to establish
multiple contact points between two components along a corresponding interface so
that a ground or return path is maintained during operation. For example, the grounding
matrix 310 is configured to provide multiple contact points along the mounting interface
327. The grounding matrix 321 is configured to provide multiple contact points along
the mounting interface 326. Similar to the grounding matrix 106 (Figure 1), the grounding
matrix 320 is configured to provide multiple contact points along the interface between
the receptacle and header connectors 306, 316. The grounding matrices 310, 320, and
321 may improve the electrical performance (e.g., improve the communication of data
signals) between the corresponding mated components.
[0038] The header connector 316 has a mating side 324 that includes electrical terminals
325 disposed therealong. Each of the electrical terminals 325 includes a contact housing
328 that surrounds a corresponding pair of electrical contacts (not shown). The receptacle
connector 306 also has a mating side 330 that includes socket cavities (not shown)
that each include a pair of electrical contacts (not shown) therein. During the mating
operation, the mating side 330 of the receptacle connector 306 is advanced toward
the mating side 324 of the header connector 316. The electrical terminals 325 are
received by corresponding socket cavities of the receptacle connector 306 and advanced
into the socket cavities until the contacts of the electrical terminals and the contacts
in the socket cavities engage each other. During the mating operation, the grounding
matrix 320 may be compressed by and between the receptacle and header connectors 306,
316 thereby establishing a ground path.
[0039] The communication system 300 may be used in various applications. By way of example,
the communication system 300 may be used in telecom and computer applications, routers,
servers, supercomputers, and uninterruptible power supply (UPS) systems. In such embodiments,
the circuit board assembly 302 may be described as a daughter card assembly and the
circuit board assembly 304 may be described a backplane connector assembly. The receptacle
and header connectors 306, 316 may be similar to electrical connectors of the STRADA
Whisper or Z-PACK TinMan product lines developed by TE Connectivity. In some embodiments,
the receptacle and header connectors 306, 316 are capable of transmitting data signals
at high speeds, such as 10 Gbps, 20 Gbps, or more. Although the communication system
300 is illustrated as a backplane system, embodiments are not limited to such systems
and may be used in other types of communication systems. As such, the receptacle and
header connectors 306, 316 may be referred to more generally as electrical connectors.
[0040] Figure 9 illustrates an isolated perspective view of the grounding matrix 310 as
well as an enlarged portion of the grounding matrix 310. Although the following description
is with respect to the grounding matrix 310, the grounding matrix 320 (Figure 8) and
the grounding matrix 321 (Figure 14) may have similar or identical features as the
grounding matrix 310. The grounding matrix 310 may be similar to the grounding matrix
106 (Figure 1). For example, as shown in Figure 9, the grounding matrix 310 can have
a substantially planar body or frame 336 that includes ground contacts 340-343 and
linkages 346, 348 that interconnect the ground contacts 340-343 in a web-like manner.
The ground contacts 340-343 and the linkages 346, 348 faun openings 350.
[0041] The grounding matrix 310 is formed from conductive material. Non-limiting examples
of materials that may be used to form the grounding matrix 310 include metal, a conductive
elastomer, an elastomer coated with a conductive material, conductive tape, and the
like. In the illustrated embodiment, the grounding matrix 310 is stamped-and-formed
from sheet metal and is conductive throughout. However, the grounding matrix 310 can
be formed in different manners in other embodiments. For example, in one alternative
embodiment, the grounding matrix may include an organizer comprising a dielectric
frame that holds the ground contacts. In some cases, at least some of these ground
contacts may be electrically isolated from others.
[0042] As shown, the grounding matrix 310 may include attachment features 352 along an outer
perimeter of the grounding matrix 310. In some embodiments, the attachment features
352 can be projections or tabs that extend in a direction that is orthogonal to a
plane defined by the grounding matrix 310. For example, the frame 336, portions of
the ground contacts 340-343, and the linkages 346, 348 may coincide within a ground
plane that is parallel to the mating and lateral axes 391, 393 in Figure 9. The attachment
features 352 may extend in a direction that is parallel to the lateral axis 392. The
attachment features 352 are configured to directly engage and couple to the receptacle
connector 306 (Figure 8) to secure the grounding matrix 310 to the receptacle connector
306.
[0043] In some embodiments, the grounding matrix 310 is floatably coupled to the receptacle
connector 306 such that the grounding matrix 310 is permitted to move relative to
the receptacle connector 306 within a restricted space. In other embodiments, the
grounding matrix 310 may directly engage and couple to the circuit board 308 (Figure
8) or, alternatively, may not couple to either the circuit board 308 or the receptacle
connector 306.
[0044] The enlarged portion of Figure 9 illustrates the ground contacts 340-343 and the
linkages 346, 348 in greater detail. The linkages 346 are configured to directly connect
the ground contacts 340, 342 to one another. For example, the linkages 346 join adjacent
ground contacts 340, 342 in Figure 9. The linkages 348 extend along a perimeter of
the grounding matrix 310 and join adjacent ground contacts, such as the ground contacts
341, 343.
[0045] Similar to the ground contacts 152 (Figure 2), the ground contacts described herein
may include one or more flex portions that extend out of a ground plane defined by
the grounding matrix 310. For example, the ground contact 342 has first and second
flex portions 354, 356 and a contact base 358 that joins the flex portions 354, 356.
The flex portions 354, 356 extend from the contact base 358 in opposite directions
away from each other to respective distal ends 355, 357 disposed at a distance from
one side of the ground plane. The ground contact 340 also has flex portions 354, 356.
However, the flex portions 354, 356 of the ground contact 340 extend in an opposite
direction from the ground plane as compared to the flex portions 354, 356 of the ground
contact 342.
[0046] In the illustrated embodiment, the flex portions 354, 356 may have a curved or curled
contour such that the flex portions 354, 356 from a single ground contact extend in
the same direction away from the ground plane. As such, the ground contacts 340, 342
may be substantially C-shaped. Also shown in Figure 9, the ground contacts 341, 343
may have only a single flex portion 361 that is similarly shaped as the flex portions
354, 356. The flex portions 361 of the ground contacts 341, 343 may extend in generally
opposite directions from the ground plane.
[0047] In some embodiments, the contact bases 358 include a base projection 359. The base
projection 359 is shaped similar to a button in Figure 9, but may have other shapes
in alternative embodiments. The base projection 359 extends from the ground plane
in a direction opposite the direction that the flex portions 354, 356 extend and,
in operation, is configured to engage an electrical component. For example, if the
flex portions 354, 356 extend toward the receptacle connector 306 (Figure 8), the
base projection 359 may extend toward and directly engage the circuit board 308 (Figure
8). If the flex portions 354, 356 extend toward the circuit board 308, the base projection
359 may extend toward and directly engage the receptacle connector 306.
[0048] Figure 10 includes a bottom perspective view of a portion of the circuit board assembly
302 and, in particular, the receptacle connector 306. The receptacle connector 306
includes a connector body 360 having a mounting side 362 and the mating side 330.
The mounting side 362 is configured to be mounted to the circuit board 308 (Figure
8) with the grounding matrix 310 therebetween. The connector body 360 may be constructed
from dielectric and conductive materials. For example, the connector body 360 includes
a conductive (e.g., metallized) housing 370 that is formed from a plurality of module
housings 372 and housing shields 374. In the illustrated embodiment, the conductive
housing 370 includes three of the module housings 372, which are stacked side-by-side
and located between a pair of the housing shields 374. Each of the module housings
372 and the housing shields 374 may include a conductive material for grounding the
circuit board assembly 302. For instance, the housing shields 374 may be stamped-and-formed
from sheet metal and the module housings 372 may include metallized exterior surfaces.
[0049] An enlarged portion of the mounting side 362 is also shown in Figure 10. The receptacle
connector 306 includes signal conductors 366 that are held by the connector body 360.
As shown, the signal conductors 366 have signal contacts (or contact tails) 368 that
project from the mounting side 362. The signal contacts 368 are configured to mechanically
and electrically engage plated thru-holes (not shown) of the circuit board 308 (Figure
8).
[0050] As shown, the signal contacts 368 extend through the openings 350 of the grounding
matrix 310. For example, the signal contacts 368 form signal pairs 376A-376C. Each
signal pair 376A-376C extends through one of the openings 350. As such, adjacent signal
pairs are separated and electrically shielded from each other by portions of the grounding
matrix 310. For example, the adjacent signal pairs 376A and 37613 are separated from
each other by one of the linkages 346, and the adjacent signal pairs 376B and 376C
are separated from each other by the ground contacts 341 and 342.
[0051] Also shown in Figure 10, the attachment features 352 may extend into corresponding
feature cavities or openings 378 of the connector body 360 and directly engage the
connector body 360. In particular embodiments, the attachment features 352 form an
interference fit or frictional engagement with surfaces of the connector body 360
that define the feature cavities 378. As such, the frame 336 may be held at a designated
position that is spaced apart from the mounting side 362 by a separation distance
X
1. In other embodiments, the attachment features 352 may grip exterior sides of the
connector body 360. In various embodiments, the surface(s) of the connector body 360
that directly engage the attachment features 352 may be conductive such that ground
pathways are formed through the attachment features 352.
[0052] In the illustrated embodiment, the attachment features 352 are stamped and formed
with the frame 336 and ground contacts. However, in other embodiments, the attachment
features 352 may be discrete elements that interconnect the frame 336 and the connector
body 360. For example, the attachment features 352 may be separate fasteners (e.g.,
clips, plugs, or other hardware) that attach the frame 336 of the grounding matrix
310 to the connector body 360.
[0053] In some embodiments, the grounding matrix 310 may be permitted to float relative
to the mounting side 362. For example, the grounding matrix 310 may be permitted to
float to and from the mounting side 362 and/or to float laterally such that the frame
336 moves parallel to the mounting side 362. To this end, the attachment features
352 may be sized and shaped relative to the feature cavities 378 such that the attachment
features 352 are permitted to move within the feature cavities 378.
[0054] Figure 11 is a top perspective view of the circuit board assembly 302 before the
receptacle connector 306 is mounted to the circuit board 308. As shown, the grounding
matrix 310 is positioned along the mounting side 362. The circuit board 308 includes
a board substrate 380 that has the engagement side 314 and the opposite side 315.
The board substrate 380 has a thickness T
1 that is measured perpendicular to the sides 314, 315.
[0055] Figure 12 shows an enlarged portion of the circuit board 308 that is outlined in
the box of Figure 11. As shown, the circuit board 308 includes signal vias 382 that
are exposed along the engagement side 314. The signal vias 382 may be arranged to
fonii multiple signal pairs 384. The circuit board 308 also includes ground vias 390
along the engagement side 314. As described below, in certain embodiments, the ground
vias 390 are positioned relative to the signal vias 382 to electrically shield the
signal vias 382 from one another. In embodiments that are configured to transmit differential
signals, the ground vias 390 are positioned relative to the signal pairs 384 to electrically
shield the signal pairs 384 from one another.
[0056] The circuit board 308 includes a conductive layer 388 and, optionally, a mask layer
386 that is located on top of the conductive layer 388. As shown, the signal vias
382 are electrically isolated from the conductive layer 388. For instance, portions
of the conductive layer 388 may be removed (e.g., etched) so that the conductive layer
388 does not connect to the signal vias 382. The conductive layer 388 may electrically
join at least some of the ground vias 390. In addition, the mask layer 386 may be
patterned such that portions of the conductive layer 388 are exposed along the engagement
side 314 and capable of engaging the ground contacts 340, 342 of the grounding matrix
310 (Figure 9) as well as the ground contacts 341, 343 (Figure 9). The exposed portions
may be referred to as contact areas 394 and may be sized and shaped relative to the
corresponding ground contacts that engage the contact areas 394.
[0057] Figure 13 is a side cross-section of the receptacle connector 306 mounted to the
circuit board 308. In particular embodiments, the signal vias 382 are plated thru-holes
(PTHs), and the ground vias 390 are microvias. Microvias may be blind vias and have
diameters that are typically smaller than diameters of the signal vias 382. For instance,
the diameters of the microvias may be less than 0.4 mm. Microvias may be manufactured
through various processes, such as those that are used to manufacture blind vias.
For example, microvias may be fabricated in one or more dielectric layers through
mechanical drilling or laser drilling (e.g., using UV or CO2 lasers to provide a bore
through the dielectric layer). Microvias may also be photo-defined or etched (e.g.,
chemical (wet) etching or plasma etching) blind vias. Once the microvias are formed,
the dielectric layers may then be laminated with other dielectric layers that have
(or will have) microvias. In this manner, the microvias from the different dielectric
layers may be effectively stacked together such that the microvias are substantially
end-to-end and form columns.
U.S. Patent Application No. 13/493,632 ("the '632 Application") describes circuit boards having ground columns that may
include microvias. Such circuit boards may include the conductive layer 388 and the
mask layer 386 described herein. The '632 Application is incorporated herein by reference
in its entirety.
[0058] As shown in Figure 13, the grounding matrix 310 extends along the mounting interface
327 that is defined between the receptacle connector 306 and the circuit board 308.
The flex portions 354 of the ground contacts 342 extend toward the mounting side 362
of the receptacle connector 306. Such ground contacts 342 may be described as inward-extending
contacts. The flex portions 354 of the ground contacts 340 extend away from the mounting
side 362 toward the engagement side 314 of the circuit board 308. Such ground contacts
340 may be described as outward-extending contacts.
[0059] The signal contacts 368 form an array 369 that includes gaps 398, which may be similar
to the gaps 142-144 (Figure 3). As shown, each gap 398 extends between adjacent signal
contacts 368. Before or during the mounting operation, the receptacle connector 306
may be coupled to the grounding matrix 310. The signal contacts 368 may be advanced
through the openings 350 and the ground contacts 340, 342 may be positioned within
corresponding gaps 398.
[0060] Figure 13 illustrates a cross-section of one of the module housings 372. As shown,
the module housing 372 includes a conductive body material 402 and dielectric ribs
404. The body material 402 defines channels 406 through which the dielectric ribs
404 extend. For example, the dielectric ribs 404 may extend continuously from the
mounting side 362 to proximate to the mating side 330 (Figure 8). Each of the dielectric
ribs 404 holds one of the signal conductors 366. The dielectric ribs 404 may be applied
to the signal conductors 366 through, for example, an overmolding process. When the
receptacle connector 306 is mounted to the circuit board 308, the ground contacts
340 directly engage the contact areas 394 of the conductive layer 388, and the ground
contacts 342 directly engage the body material 402. As shown, the contact areas 394
may have a width W
1 that is greater than a width W
2 of the ground contact 340 to ensure that the ground contacts 340 will engage the
conductive layer 388 without riding on the mask layer 386.
[0061] The ground contacts 340, 342 resiliently flex with respect to the mounting side 362
or the engagement side 314 when the receptacle connector 306 is mounted to the circuit
board 308. With the ground contacts 340, 342 directly engaging the engagement and
mounting sides, 314, 362, respectively, the grounding matrix 310 establishes at least
one ground pathway through the grounding matrix 310 between the receptacle connector
306 and the circuit board 308. Ground pathways may also be formed through the conductive
body material 402 of the receptacle connector 306 and the ground vias 390 of the circuit
board 308.
[0062] As shown in Figure 13, the signal contacts 368 directly engage the signal vias 382.
More specifically, the signal contacts 368 frictionally engage interior surfaces of
the signal vias 382. Collectively, these frictional engagements provide a retention
force. In some embodiments, the retention force is greater than a separation force
exerted by the ground contacts 340, 342. In other embodiments, additional elements,
such as fasteners, may be used to attach the receptacle connector 306 to the circuit
board 308.
[0063] During the mounting operation, the signal contacts 368 are inserted into corresponding
signal vias 382 of the circuit board 308. As the signal contacts 368 are advanced
into the signal vias 382, the ground contacts 340, 342 are compressed such that the
flex portions 354 and the flex portions 356 (not shown) are moved toward the mounting
side 362. The resilient nature of the flex portions 354, 356 permits the flex portions
354, 356 to independently flex with respect to the mounting side 362. In other words,
each of the flex portions 354, 356 may be deflected more or less than other flex portions
354, 356. As such, multiple contact points between the grounding matrix 310 and the
engagement side 314 and multiple contact points between the grounding matrix 310 and
the mounting side 362 may be formed and sustained throughout operation of the circuit
board assembly 302.
[0064] Figure 14 includes a bottom perspective view of a portion of the circuit board assembly
304 and, in particular, the header connector 316 and the grounding matrix 321. The
header connector 316 includes a connector body 410 having a mounting side 412 and
the mating side 324. The mounting and mating sides 412, 324 face in opposite directions.
The connector body 410 includes a pair of housing walls 418, 420 that project from
the mating side 324 in a direction parallel to the electrical terminals 325. The housing
walls 418, 420 define a connector-receiving region 422 therebetween. The connector-receiving
region 422 is sized and shaped to receive the mating side 330 (Figure 8) of the receptacle
connector 306 (Figure 8). The electrical terminals 325 are disposed within the connector-receiving
region 422.
[0065] As shown in the enlarged portion of Figure 14, the header connector 316 also includes
signal conductors 414 that are held by the connector body 410. The signal conductors
414 extend substantially linearly through the connector body 410 and include signal
contacts (or contact tails) 416 that project from the mounting side 412. The signal
contacts 416 are configured to mechanically and electrically engage plated thru-holes
(not shown) of the circuit board 318 (Figure 8).
[0066] The signal contacts 416 and the grounding matrix 321 may have similar configurations
as the configurations of the signal contacts 368 (Figure 10) and the grounding matrix
310 (Figure 8). For example, as shown in the enlarged portion of Figure 14, the signal
contacts 416 form signal pairs 424A-424C and each signal pair 424A-424C extends through
a corresponding opening 426 of the grounding matrix 321.
[0067] Adjacent signal pairs are separated and electrically shielded from each other by
portions of the grounding matrix 321. More specifically, the adjacent signal pairs
424A and 424B are separated from each other by a linkage 428, and the adjacent signal
pairs 424B and 424C are separated from each other by ground contacts 430, 432.
[0068] The grounding matrix 321 also includes attachment features 434. Like the attachment
features 352 (Figure 9), the attachment features 434 may be projections or tabs that
are configured to directly engage the connector body 410. The attachment features
434 may extend into corresponding feature cavities or openings 436 of the connector
body 410 and directly engage the connector body 410. In particular embodiments, the
attachment features 434 form an interference fit with surfaces of the connector body
410 that define the feature cavities 436. As such, a frame 438 of the grounding matrix
321 may be held at a designated position that is spaced apart from the mounting side
412 by a separation distance X
2. Like the grounding matrix 310, the grounding matrix 321 may be permitted to float
with respect to the mounting side 412. For example, the grounding matrix 321 may be
permitted to float to and from the mounting side 412 and/or to float laterally such
that the frame 438 moves parallel to the mounting side 412.
[0069] Although not shown, the header connector 316 may be mounted to the circuit board
318 in a similar manner as described with respect to the receptacle connector 306
(Figure 8) and the circuit board 308 (Figure 8). When mounted, the ground contacts
(e.g., the ground contacts 430, 432) of the grounding matrix 321 may directly engage
the engagement side 322 (Figure 8) of the circuit board 318 and the mounting side
412 of the header connector 316. As such, multiple contact points between the grounding
matrix 321 and the engagement side 322 and multiple contact points between the grounding
matrix 321 and the mounting side 412 may be formed and sustained throughout operation
of the circuit board assembly 304 (Figure 8). In addition to the grounding matrix
321, ground pathways may be formed through conductive body material (not shown) of
the connector body 410 and ground vias (not shown) of the circuit board 318 in a similar
manner as described above with respect to the circuit board assembly 302 (Figure 8).
[0070] Figure 15 is a plan view of the circuit board 308 and illustrates one arrangement
of the signal vias 382, the ground vias 390, and the contact areas 394 in greater
detail. It should be noted that the circuit board 318 (Figure 8) can be similar or
identical to the circuit board 308. The signal vias 382 are arranged to form a plurality
of signal pairs 384. In the illustrated embodiment, the signal pairs 384 are arranged
in a row and column configuration although other configurations may be used. As shown,
the conductive layer 388, which is shaded in Figure 15, spans across the engagement
side 314 under the mask layer 386 and joins the ground vias 390.
[0071] The contact areas 394 of the conductive layer 388 are exposed along the engagement
side 314. In Figure 15, the contact areas 394 form elongated strips 442 in which each
elongated strip 442 joins a plurality of the ground vias 390. The elongated strips
442 may extend continuously along one dimension of the engagement side 314. In an
exemplary embodiment, the conductive layer 388 extends beneath the mask layer 386
such that each elongated strip 442 is part of a single layer. Alternatively, the conductive
layer 388 may be, for example, etched such that the elongated strips 442 are part
of separate structures along the engagement side 314.
[0072] The contact areas 394 are sized and shaped to be directly engaged by the ground contacts
340-343 (Figure 9) when the receptacle connector 306 (Figure 8) is mounted onto the
circuit board 308 as described herein. For example, contact points 444 are indicated
along the contact areas 394 in Figure 15. The contact points 444 represent areas where
the distal ends 355, 357 (Figure 9) of the ground contacts 340-343 directly engage
the contact areas 394. Due to tolerances in manufacturing of the various components
of the receptacle connector 306 and the grounding matrix 310 (Figure 9), the size
and shape of the contact areas 394 may permit some misalignment between the distal
ends 355, 357 and the conductive layer 388. Furthermore, during a mounting operation,
the size and shape of the contact areas 394 may permit the distal ends 355, 357 of
the ground contacts 340-343 to slide along the conductive layer 388 (also referred
to as "wiping").
[0073] In certain embodiments, the ground vias 390 are positioned to form shield arrays
440 that surround corresponding signal pairs 384. Representative perimeters of the
shield arrays 440A and 440B are indicated by dashed lines that extend between and
connect the corresponding ground vias 390 of the corresponding shield arrays 440A,
440B. The shield arrays 440 may be similar to the shield arrays described in the '632
Application, which is incorporated herein by reference in its entirety.
[0074] The shield arrays 440 are configured to reduce crosstalk experienced by the signal
pairs 384. By way of example, the signal pairs 384A and 384B are adjacent signal pairs.
The shield arrays 440A, 440B surround the signal pairs 384A and 384B, respectively.
In the illustrated embodiment, each of the shield arrays 384A and 384B includes eight
ground vias 390. However, alternative configurations of the shield arrays may include
fewer or more ground vias. In particular embodiments, the shield arrays 440A, 440B
may share common ground vias 390'. For example, the shield arrays 440A, 440B share
two common ground vias 390'. In other embodiments, the shield arrays 341343 may not
share common ground vias.