The present invention is related to electrical connector assemblies. In particular, the present invention is related to high-speed, high-density electrical connector assemblies for interconnecting two or more circuit boards.
To simplify manufacturing and reduce overall costs, an electronic system is generally manufactured on separate printed circuit boards. These separate printed circuit boards are then connected to one another by electrical connectors. Typically, one printed circuit board serves as a backplane. Then other printed circuit boards, which are often called daughter boards or daughter cards, are connected to the backplane by electrical connectors to form the electronic system.
To meet demands for electronic systems that are more compact, faster, and more complex, progressively more circuits are placed within a given area of each printed circuit board, and those additional circuits operate at increasingly higher frequencies. Therefore, the electrical connectors between the printed circuit boards have to pass data at increasingly higher rates and higher signal frequencies. For faster data processing, current electronic systems require faster data transmission between printed circuit boards.
Because of the increasing signal frequencies, electrical connectors encounter more electrical noise. The electrical noise often manifests itself as signal reflections, crosstalk, electromagnetic radiation, or other similar forms of electrical noise. Signal reflection occurs when a portion of a signal being transmitted is reflected back to the signal source instead of being transmitted to the signal destination. Signal reflections are caused by signal path imperfections that give rise to impedance mismatching. Also, changes in the signal path characteristics, particularly abrupt changes, can cause signals to be reflected.
Crosstalk is electromagnetic coupling of one signal path with another signal path. The coupling results in one signal affecting another nearby signal. To reduce electrical noise in the form of crosstalk, signal paths are arranged so that the signal paths are spaced farther apart from each other and nearer to a shield plate which is generally the ground plate or a conductor connected to ground, such as described in U.S. Patent Application Pub. No. 2004/0264153 to Payne et al., entitled “Printed Circuit Board for High Speed, High Density Electrical Connector with Improved Cross-Talk Minimization, Attenuation and Impedance Mismatch Characteristics,” which is incorporated by reference herein in its entirety. Therefore, the signal paths tend to couple electromagnetically more with the shield plate or ground conductor and less with each other. For a particular level of crosstalk, the signal paths can be placed closer to each other as long as sufficient electromagnetic coupling to the shield plate or a ground conductor is maintained.
Also, in a region where the signal path electrically connects to another circuit, manufacturing costs are relatively higher since the signal path must be formed and shaped to provide an acceptable electrical connection that is mechanically durable. Such connections are typically more difficult to manufacture because a more complicated shape is required and complicated shapes are more costly to form. The connections also need electromagnetic coupling to the shield plate or to ground conductors to minimize crosstalk.
An electrical connector is described in U.S. Pat. No. 6,409,543 Astbury, Jr. et al., entitled “Connector Molding Method and Shielded Waferized Connector Made Therefrom,” the entire disclosure of which is incorporated herein by reference. The electrical connector is assembled from wafers, and each wafer is formed by molding a dielectric housing over a shield plate. Signal conductors are inserted into the dielectric housing. A mating contact region is provided near an edge of the wafer where the signal conductors mate with a backplane connector. In the mating contact region, the signal conductors mate with the signal contacts of the backplane connector. Provided near the edge of the wafer are shield beam contacts. The shield beam contacts are connected to the shield plate and engage an upper edge of the shield plate in the backplane connector that forms a current path to reduce crosstalk. However, the shield beam contact provides only a single current path to reduce electromagnetic coupling and crosstalk, and a substantial amount of the shield plate is not utilized, thereby diminishing the effectiveness of the shield plate.
Another approach to provide shielding between adjacent connections and to reduce costs is to use plastic containing conductive materials, such as the connector described in U.S. Patent Application Pub. No. 2007/0042639 to Manter et al., entitled “Connector with Inproved Shielding in Mating Contact Region,” which is incorporated by reference herein in its entirety. However, the use of plastic containing conductive materials between signal paths does not provide the stiffness, the shielding, and the lower relative manufacturing cost of using a metal shield.
Therefore, there is a need in the art for a high speed, high density electrical connector design that minimizes crosstalk, provides increased conductive metal content around the contact region, and lowers manufacturing costs.
Accordingly, one object of the invention is to provide additional current paths between two or more shields. Another object of the invention is to provide an electrical connector assembly. Yet another object of the invention is to minimize crosstalk. A further object of the invention is to maximize the use of the shield.
One embodiment of the invention provides an electrical connector. The electrical connector includes a shield plate, a first finger that extends from an edge of the shield plate, and a second finger that extends from the edged of the shield and that is adjacent to the first finger. A channel is formed between the first finger and the second finger. A coupling is placed within the channel adjacent the first finger. The coupling includes a contact, a first connecting arm extending from a first end of the contact to a first portion of the first finger, and a second connecting arm extending from a second end of the contact to a second portion of the first finger. The first connecting arm and the second connecting arm provide at least two current paths from the contact to the first finger.
Another embodiment of the invention provides an electrical connector. The electrical connector includes a first wafer and a second wafer placed adjacent the first wafer. The first wafer has a first shield plate, first shield couplings in pairs along an edge of the first shield plate to form a first column of first shield couplings, and first signal conductors adjacent the first shield plate between respective pairs of first shield couplings. The second wafer has a second shield plate, second shield couplings along an edge of the second shield plate to form a second column of second shield couplings parallel to the first column of first shield couplings, and second signal conductors in pairs adjacent the second shield plate. At least one of the pair of first shield couplings is adjacent to one of the first signal conductors and at least one of the second signal conductors. Also, at least one of the second shield couplings is adjacent to one of the second signal conductors and at least one of the first signal conductors.
Yet another embodiment of the invention provides an electrical connector assembly. The electrical connector assembly includes a first wafer and a second wafer adjacent the first wafer. The first wafer has a first shield plate, a first finger extending from an edge of the first shield plate, a second finger adjacent to the first finger and extending from the edge of the first shield plate. A first channel is formed between the first finger and the second finger, and a first coupling is within the first channel adjacent the first finger. The first coupling includes a first contact, a first connecting arm extending from a first end of the first contact to a first portion of the first finger, and a second connecting arm extending from a second end of the first contact to a second portion of the first finger. The first connecting arm and the second connecting arm provide at least two current paths from the first contact to the first finger. The second wafer has a second shield plate, a third finger extending from an edge of the second shield plate, and a fourth finger adjacent to the third finger and extending from the edge of the second shield plate. A second channel is formed between the third finger and the fourth finger, and a second coupling is within the second channel adjacent the third finger. The second coupling includes a second contact, a third connecting arm extending from a first end of the second contact to a first portion of the third finger, and a fourth connecting arm extending from a second end of the second contact to a second portion of the third finger. The third connecting arm and the fourth connecting arm provide at least two current paths from the second contact to the third finger. The electrical connector assembly also has a third shield received in the first channel and the second channel where the third shield engages the first contact and the second contact. The electrical connector assembly further includes a fourth shield disposed substantially transverse to the third shield.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the invention.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
As shown in
Referring back to
The first circuit board 500 provides a surface 502 for electrical components and their interconnections. The surface 502 is preferably made of a dielectric material, and the first circuit board 500 can have more than one surface 502. If the first circuit board 500 has several surfaces 502, the electrical components on different surfaces 502 can be interconnected by vias, as described in co-pending U.S. patent application Ser. No. 11/717,634 by Chan et al., entitled “Adjacent Plated Through Holes with Staggered Couplings for Crosstalk Reduction in High Speed Printed Circuit Boards,” filed Mar. 14, 2007, the entire disclosure of which is incorporated herein by reference. The first circuit board 500 also includes a first circuit board coupling 504. The first circuit board coupling 504 provides electrical, mechanical, or electromechanical coupling between the first circuit board 500 and another electrical component. The first circuit board coupling 504 can be a plated through hole or via. The first circuit board coupling 504 can be electrically connected to a pathway for a signal or to a reference voltage, such as ground. The number of first circuit board couplings 504 illustrated is exemplary only and is not intended to be limiting.
The second circuit board 600 provides another surface 602 for electrical components and their interconnections. The second circuit board 600 includes a second circuit board coupling 604. The second circuit board 600, the surface 602, and the second circuit board coupling 604 are substantially similar to the first circuit board 500, the surface 502 of the first circuit board 500, and the first circuit board coupling 504, respectively.
The first and second connectors 100 and 400 are configured so that the first and second circuit boards 500 and 600 are connected when they are substantially orthogonal to each other, as shown in
The first connector 100 includes a first wafer 200 and a second wafer 300. The first and second wafers 200 and 300 couple to the first circuit board 500 and the second connector 400. The first and second wafers 200 and 300 each provide shielded, conductive pathways between the first circuit board 500 and the second connector 400. In the embodiment shown, the wafers 200 and 300 have a planar structure so that the wafers 200 and 300 can be placed adjacent to each other to form the first connector 100. The planes of the wafers 200 and 300 are parallel to each other. Also, the first and second wafers 200 and 300 are alternately disposed with one another to form a repeating pattern of first and second wafers 200, 300, 200, 300, etc., so that adjacent wafers 200 and 300 can provide shielding to each other's shielded, conductive pathways. Although only two wafers 200 and 300 are shown for clarity, the first connector 100 may have more than two wafers 200 and 300. The optimal number of wafers 200 and 300 depends on the configuration of the first and second circuit boards 500 and 600, for instance, the number of shielded, conductive pathways required between the first and second circuit boards 500 and 600. The first and second wafers 200 and 300 couple to the second connector 400, and the second connector 400 provides shielded, conductive pathways from the wafers 200 and 300 of the first connector 100 to the second circuit board 600.
The first and second wafers 200 and 300 can be supported by a stiffener (not shown), such as the one described in U.S. Pat. No. 5,672,064 to Provencher et al, entitled “Stiffener for Electrical Connector,” the entire disclosure of which is incorporated herein by reference. Each wafer 200 and 300 has one or more inserts 102 which are inserted into corresponding apertures in the stiffener to locate each wafer 200 and 300 with respect to one another and to prevent undesired movement or rotation of the wafers 200 and 300.
Referring to
The third shield 410 couples with a second shield coupling 214 of the first wafer 200 and a fourth shield coupling 314 of the second wafer 300. The third shield 410 also couples with the fourth shield 420. The third shield 410 and the fourth shield 420 couple with each other substantially perpendicularly. In the embodiment shown, a multitude of third shields 410 is provided substantially parallel to one another, and a multitude of fourth shields 420 is provided substantially parallel to one another, thus when the third and fourth shields 410 and 420 are provided substantially perpendicular to each other, the third and fourth shields 410 and 420 surround a pair of third and fourth signal conductors 430 and 440.
At one of their respective ends, the third and fourth signal conductors 430 and 440 couple with a second signal contact 234 of the first wafer 200 and a fourth signal contact 334 of the second wafer 300. Preferably, the third and fourth signal conductors 430 and 440 are provided in pairs to form differential pairs. Thus, the third signal conductor 430 couples with the second signal contact 234 or the fourth signal contact 334, while the fourth signal conductor 440 couples with the remaining fourth or second signal contact 334 or 234. At their respective opposite ends, the third and fourth signal conductors 430 and 440 couple with their respective second circuit board coupling 604 (shown in
The second connector 400 also includes a bottom surface 402 and sidewalls 404. Preferably, the second connector 400 has two sidewalls 404 opposite each other and extending substantially the length of two opposing edges of the bottom surface 402. The bottom surface 402 is adapted to receive the fourth shield 420, the third signal conductor 430, and the fourth signal conductor 440. In the embodiment depicted, the bottom surface 402 receives and holds in place the fourth shields 420, the third signal conductors 430, and the fourth signal conductors 440. At least one of the sidewalls 404 of the second connector 400 is adapted to receive the first and second wafers 200 and 300. The sidewalls 404 preferably have grooves 405 adapted to slidably receive, guide, and hold the first and second wafers 200 and 300 in the second connector 400. The grooves 405 run vertically along an inner surface of the sidewalls 404.
In the embodiment shown, the second connector 400 includes an alignment pin 406 and an alignment pin receptacle 408. The alignment pin 406 is received by an end block, as shown and described in U.S. Patent Application Pub. No. 2004/0264153 to Payne et al. Similarly, the guide pin receptacle 408 receives a corresponding guide pin from the end block. In Payne et al., the end blocks have a guide pin which is received by the guide pin receptacle 408 and an alignment pin receptacle that receives the alignment pin 406. The first and second wafers 200 and 300 are also attached to the end blocks by the stiffener and can be connected to the second connector 400 as one single unit.
As shown in
Referring to
The first shield plate 210 has a first shield coupling 212 and a second shield coupling 214. In the embodiment shown, the first shield plate 210 has a multitude of first shield couplings 212a-212j that are disposed along one side edge of the first shield plate 210. The first shield couplings 212a-212j couple with respective first circuit board couplings 504 that are connected to a reference voltage, such as ground. As shown, the first shield couplings 212a-212j are disposed in differential pairs and extend out from a leading side edge of the first shield plate 210. The first shield couplings 212a-212j are preferably press-fit contacts that are received by the first circuit board couplings 504, but can also be any other suitable mechanical, electrical, or electromechanical coupling. The first shield couplings 212a-212j are also not in the same plane as the first shield extensions 213. The first shield couplings 212a-212j are bent in a general S-shape so that the first shield couplings 212a-212j are substantially parallel to and above (in the embodiment of
As shown in
Disposed along the bottom edge of the first shield plate 210 are a multitude of fingers 201 with receiving channels 203 between the fingers 201. Since the connector assembly 10 couples the first circuit board 500 to a second circuit board 600 that is substantially perpendicular to the first circuit board 500, the fingers 201 are on an edge that is substantially perpendicular to the first shield couplings 212a-212j. The fingers 201 are substantially planar structures that extend from the first shield plate 210 parallel to the plane of the first shield plate 210. The fingers 201 have at least one recess 239 on the side adjacent the receiving channel 203. The recess 239 has at least one second shield coupling 214 that has a shield contact 216 with connection arms 218a, b that connect the shield contact 216 to the rest of the finger 201. The second shield coupling 214 also includes current paths 215, 217, a shield contact 216, a deflecting portion 220, a protrusion 222, and a tab 223. The second shield coupling 214 couples the first shield plate 210 with the third shield 410. In the embodiment shown, the second shield coupling 214 has two shield contacts 216 that receive the fifth shield coupling 412 of the third shield 410 (
A stiffening member 219 is provided on each finger 201. The stiffening member 219 provides structural support to the fingers 201. Because the fingers 201 are cut out of and formed from the first shield plate 210, areas near the fingers 201 require extra structural support to prevent buckling during manufacturing, coupling, and assembly. The stiffening member 219 is made during the stamping process that forms the first shield plate 210 and has a substantially semi-circular cross-section. The stiffening member 219 extends substantially the length of the finger 201. The substantially semi-circular cross-section and length of the stiffening member 219 increases the rigidity and deflection resistance of the finger 201. A hole 243 may be stamped into the stiffening member 219 to provide an anchor for the insulative body 202.
Referring to
In the embodiment shown, the shield contact 216 has a deflecting portion 220. The deflecting portion 220 prevents stubbing when the third shield coupling 412 slidably enters the receiving channel 203 to engage the shield contact 216 of the second shield coupling 214. The leading end of the shield contact 216 is turned back toward the connecting arm member 218a or 218b to form the deflecting portion 220. The deflecting portion 220 is disposed on the shield contact 216 where it first engages the third shield 410. In one embodiment, the shield contact 216 is formed by stamping. After stamping, the first shield plate 210 is shaped, folded, deformed, or otherwise manipulated to form the shield contacts 216. In particular, metal in the region of the first shield plate 210 where the shield contacts 216 are formed is stamped and then the stamped shape is folded twice to form the shield contacts 216. In the embodiment shown, the shield contacts 216 are folded once substantially perpendicular to the plane of the first shield plate 210 (out of the page in the embodiment of
The shield contact 216 also has a protrusion 222 that provides a point of contact between the first shield plate 210 and the third shield 410. The protrusion 222 has a substantially hemispherical shape to provide a better connection point between the first shield plate 210 and the third shield 410. When the shield contact 216 engages the third shield 410, the protrusion 222 causes the shield contact 216 to elastically flex away from the third shield 410. The shield contact 216 is thus biased toward the third shield 410 by the connecting arm members 218a and 218b to maintain contact between the shield contact 216 and the third shield 410. The protrusion 222 concentrates forces so that higher contact pressure between the shield contact 216 and the third shield 410 ensures a good connection. The shape of the protrusion 222 cuts through the dust, oil, debris, and other obstructions that can prevent an electrical connection between the shield contact 216 and the third shield 410. In one embodiment, the protrusion 222 formed by stamping. The shield contacts 216, the connecting arm members 218a and 218b, the deflecting portion 220, and the protrusion 222 are preferably made of the same material as the first shield plate 210.
The insulative body 202 has a cap portion 205 formed over the shield plate fingers 201. The cap portion 205 protects the second contacts 234. The cap portion 205 has angled surfaces 221 and separate passageways 237. Angled surfaces 221 are provided at the entrance of the second shield coupling 214, and the angled surfaces 221 guide the third shield 410 to enter the channel 203 between the shield contacts 216. The angled surfaces 221 prevent stubbing of the third shield 410 as it is received by the second shield coupling 214.
The separate passageways 237 have inclined surfaces 235 near the second contacts 234. The inclined surfaces 235 prevent stubbing of the third and fourth signal conductors 430 and 440 as they couple with the second contacts 234. The inclined surfaces 235 are inclined inwardly so that the third and fourth signal conductors 430 and 440 are aligned with the second contacts 234 and mate properly.
Referring to
Each first contact 232a-232j couples with one of the first circuit board couplings 504. Preferably, the first contact 232a-232j is a press-fit “eye of the needle” compliant contact that is pressed into a plated through hole or another structure disposed as the first circuit board coupling 504 on the first circuit board 500. However, other configurations for the first contact 232a-232j are suitable, such as surface mount elements, spring contacts, solderable pins, and other similar mechanical, electrical, or electromechanical couplings. Furthermore, the first signal conductor pairs 230 are formed so as to be disposed between adjacent first shield couplings 212a-212j and adjacent second shield couplings 214a-214j. The second contact 234 can be a dual beam contact, as shown, or any other electrical, mechanical, or electromechanical coupling.
Referring to
Also, the first shield couplings 212a-212j have a bend so as to be offset from the plane of the first shield plate 210 and aligned with the first contacts 232a-232j of the first signal conductor pairs 230. Thus, the couplings 212a-212j and the contacts 232a-232j form a single linear column along the edge of the first wafer 200, as best shown in
As shown in
Referring to
Unlike the first shield plate 210 where the first shield couplings 212a-212j are disposed in pairs along one edge, the second shield plate 310 has at least one unpaired third shield coupling 312a and 312j. The unpaired third shield couplings 312a and 312j are provided to ensure that the first shield couplings 212a-212j are not aligned with the third shield couplings 312a-312j when wafers 200 and 300 are placed adjacent to each other. Thus, the first shield couplings 212a-212j and third shield couplings 312a-312j provide signal shielding to adjacent third and first contacts 332a-332j and 232a-232j. In the embodiment depicted in
The fourth shield coupling 314 includes at least one or more shield contacts 316. The shield contacts 316 are substantially similar to the shield contacts 216 of the first wafer 200. The shield contacts 316 also provide more than one current path 315 and 317. Referring to
The insulative body 302 has a cap portion 305 formed over the shield plate fingers 301. The cap portion 305 is substantially similar to the cap portion 205 of the first wafer 200. The cap portion 305 protects the fourth contacts 334. The cap portion 305 has angled surfaces 321 and separate passageways 337 substantially similar to angled surfaces 221 and separate passageways 237 of the cap portion 205 of the first wafer 200. Angled surfaces 321 are provided at the entrance of the second shield coupling 314, and the angled surfaces 321 guide the third shield 410 to enter the channel 303 between the shield contacts 316. The angled surfaces 321 prevent stubbing of the third shield 410 as it is received by the fourth shield coupling 314.
Referring to
Referring to
Referring to
In addition, the first shield coupling 212a-212j of the first wafer 200 and the third shield coupling 312a-312j of the second wafer 300 are disposed adjacent to the first and third contacts 232a-232j or 332a-332j of the adjacent wafer 200 or 300. The first and third shield couplings 212a-212j and 312a-312j shield a third or first contact 332a-332j or 232a-232j in an adjacent wafer 300 or 200. The first shield couplings 212a-212j of the first wafer 200 are disposed such that they are adjacent to at least one of the third contacts 332a-332j of the second wafer 300. For example, the first shield coupling 212b and 212d are adjacent to and shield the third contact 332a and 332c, respectively. Similarly, for instance, the third shield coupling 312b and 312d of the second wafer 300 are adjacent to and shield the first contacts 232b and 232d of the first wafer 200, respectively. Therefore, the first and third contacts 232a-232j and 332a-332j are shielded by the shield couplings 312a-312j and 212a-212j in adjacent wafers and also by the shield couplings 212a-212j and 312a-312j in their own respective wafer 200 or 300. Thus, for example, the first contacts 232a-232j are shielded by adjacent first shield couplings 212a-212j within its column and by third shield couplings 312a-312j in an adjacent column. Similarly, third contacts 332a-332j are shielded by adjacent third shield couplings 312a-312j within its column and shielded by first shield couplings 212a-212j in an adjacent column.
Referring to
The third shield 410 can also have a mating clasp 416 and/or a strengthening rib 418. The mating clasp 416 couples the third shield 410 to the second connector 400. In the embodiment depicted, the mating clasp 416 are placed between adjacent sixth shield couplings 414 and couples with the bottom surface 402 of the second connector 400, such as through an opening 417 that is smaller in width then the mating clasp 416, as shown in FIG. 24. The strengthening rib 418 provides structural support to the third shield 410 and prevents buckling of the third shield 410 during manufacturing, coupling, and assembly. In the embodiment shown in
Referring to
Referring to
Referring to
Also, the center axis 433 of the fifth contact 432 is not aligned with the center axis 435 of the sixth contact 434. Rather, the sixth contact 434 is offset to one side of the center axis 433 of the fifth contact 432. Referring to
The third signal conductor 430 can also have a supporting member 436. The supporting member 436 provides structural support to the third signal conductor 430 to prevent buckling during manufacturing, coupling, or assembly.
Referring to
Referring to
Referring to
As shown in
As shown in
Referring to
Referring to
As apparent from the above description, the invention provides an electrical connector assembly 10. The electrical connector assembly 10 maximizes the effectiveness of the shields 210 and 310 by providing more paths for shield currents thereby improving the effectiveness of the shields 210 and 310. The shield currents provide more electromagnetic coupling to the shield 210 and 310 thus reducing crosstalk between adjacent signal conductor pairs 230 and 330. The improved effectiveness of the shield 210 and 310 provides better shielding and improves crosstalk reduction.
While a particular embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
3669054 | Desso et al. | Jun 1972 | A |
6247970 | Ueno et al. | Jun 2001 | B1 |
6250942 | Lemke et al. | Jun 2001 | B1 |
6409543 | Astbury, Jr. et al. | Jun 2002 | B1 |
6506076 | Cohen et al. | Jan 2003 | B2 |
6551140 | Billman et al. | Apr 2003 | B2 |
6592381 | Cohen et al. | Jul 2003 | B2 |
6602095 | Astbury, Jr. et al. | Aug 2003 | B2 |
6709294 | Cohen et al. | Mar 2004 | B1 |
6780054 | Yip et al. | Aug 2004 | B2 |
6872085 | Cohen et al. | Mar 2005 | B1 |
7094102 | Cohen et al. | Aug 2006 | B2 |
7108556 | Cohen et al. | Sep 2006 | B2 |
7285018 | Kenny et al. | Oct 2007 | B2 |
7320621 | Laurx et al. | Jan 2008 | B2 |
7621779 | Laurx et al. | Nov 2009 | B2 |
20040264153 | Payne et al. | Dec 2004 | A1 |
20050283974 | Richard et al. | Dec 2005 | A1 |
20070042639 | Manter et al. | Feb 2007 | A1 |
20070054554 | Do et al. | Mar 2007 | A1 |
20070059961 | Cartier et al. | Mar 2007 | A1 |
20070149057 | Cohen et al. | Jun 2007 | A1 |
Number | Date | Country | |
---|---|---|---|
20100093216 A1 | Apr 2010 | US |