Patent Application
20250070519
The subject matter herein relates generally to electrical connectors.
Electrical connectors are typically used to electrically couple various types of electrical devices to transmit signals between the devices. At least some known cable assemblies have cables between electrical connectors, which are coupled to corresponding electrical devices. The cables each have a signal conductor, or a differential pair of signal conductors surrounded by a shield layer that, in turn, is surrounded by a cable jacket. The shield layer includes a conductive foil, which functions to shield the signal conductor(s) from electromagnetic interference (EMI) and generally improve performance. A drain wire may be provided within the cable, electrically connected to the conductive foil. At an end of the communication cable, the cable jacket, the shield layer, and insulation that covers the signal conductor(s) may be removed (e.g., stripped) to expose the signal conductor(s) and the drain wire. The exposed portions of the signal conductor(s) are then mechanically and electrically coupled (e.g., soldered) to corresponding conductors, such as signal pads of a circuit card. The exposed portions are bent and manipulated between the insulator and the signal pads on the circuit card.
However, signal integrity and electrical performance of the electrical connectors are negatively impacted at the interface between the cables and the circuit card. For example, as the signal conductors transition to the circuit card, the cable shield no longer shields the exposed portions of the signal conductors, which affects signal integrity and detrimentally affects performance. Shields may be provided to cover the ends of the cables. However, shielding effectiveness may be poor based on the shape of the shield and gaps or openings in the shield. Assembly of multiple shields to the circuit card may be time consuming and add to the overall assembly cost.
Accordingly, there is a need for an electrical connector having an improved shielded interface with a circuit card that may be manufactured in a cost effective and reliable manner.
In one embodiment, a cable card assembly for an electrical connector is provided and includes a circuit card that has an array of signal pads on a surface of the circuit card. The circuit card has a ground plane. The cable card assembly includes cables terminated to the circuit card. The cables include signal conductors and cable shields surrounding the corresponding signal conductors to provide electrical shielding for the signal conductors. The signal conductors are electrically connected to corresponding signal pads of the circuit card. The cable card assembly includes a ground bus coupled to the circuit card. The ground bus is electrically connected to the cable shields of the cables. The ground bus is electrically connected to the ground plane of the circuit card. The ground bus includes a shell to form pockets that receive the corresponding cables. The shell is mounted to the circuit card. The shell includes solder standoff posts extending from an inner end of the shell. The solder standoff post holds the inner end elevated from the surface of the circuit card. The solder standoff posts are terminated to the circuit card.
In another embodiment, a cable card assembly for an electrical connector is provided and includes a circuit card that has an array of signal pads on a surface of the circuit card. The signal pads are arranged in pairs. The array of signal pads are arranged in multiple rows. The circuit card has a ground plane. The cable card assembly includes cables having ends terminated to the circuit card. The cables are arranged in rows. Each cable includes a pair of signal conductors and a cable shield surrounding the corresponding signal conductors to provide electrical shielding for the signal conductors. The signal conductors are electrically connected to corresponding signal pads of the circuit card. The cable card assembly includes a ground bus coupled to the circuit card. The ground bus extends between a front and a rear. The ground bus is electrically connected to the cable shields of the cables. The ground bus is electrically connected to the ground plane of the circuit card. The ground bus includes a shell to form pockets that receive the corresponding cables. The pockets are arranged in a plurality of rows between the front and the rear of the ground bus. The shell has an inner bus member and a plurality of outer bus member coupled to the inner bus member. The inner bus member is mounted to the circuit card. Each outer bus member covers the ends of a different row of the cables.
In a further embodiment, a cable card assembly for an electrical connector is provided and includes a circuit card that has an array of signal pads on a surface of the circuit card. The signal pads are arranged in pairs. The array of signal pads are arranged in multiple rows. The circuit card has a ground plane. The cable card assembly includes cables that have ends terminated to the circuit card. The cables are arranged in rows. Each cable includes a pair of signal conductors and a cable shield surrounding the corresponding signal conductors to provide electrical shielding for the signal conductors. The signal conductors are electrically connected to corresponding signal pads of the circuit card. The cable card assembly includes a ground bus coupled to the circuit card. The ground bus extends between a front and a rear. The ground bus is electrically connected to the cable shields of the cables. The ground bus is electrically connected to the ground plane of the circuit card. The ground bus includes a shell forming pockets receiving the corresponding cables. The pockets are arranged in a plurality of rows between the front and the rear of the ground bus. The shell is mounted to the circuit card. The shell covers the ends of the cables. The shell includes solder standoff posts that extend from an inner end of the shell. The solder standoff post holds the inner end elevated from the surface of the circuit card. The solder standoff posts are terminated to the circuit card.
In an exemplary embodiment, the second electrical connector 106 is a receptacle connector. The second electrical connector 106 may be a socket connector, such as a header connector. In other embodiments, the second electrical connector 106 may be a card edge connector having a card slot. The first electrical connector 102 is mated to the second electrical connector 106 at a separable interface. In an exemplary embodiment, the first electrical connector 102 is a plug connector configured to be pluggably coupled to the second electrical connector 106. For example, a portion of the first electrical connector 102 may be plugged into a receptacle or opening or slot of the second electrical connector 106. In an exemplary embodiment, the first electrical connector 102 is coupled to the second electrical connector 106 at a separable interface. For example, the first electrical connector 102 is latchably coupled to the second electrical connector 106 using a clip or latching elements. The latch may be releasable to allow removal of the first electrical connector 102 from the second electrical connector 106. The connectors 102, 106 may be input-output (I/O) connectors.
With additional reference to
With additional reference to
The ground bus 300 provides electrical shielding for the signal conductors of the cables 104 and the circuit conductors of the circuit card 132. The ground bus 300 is electrically connected to the shield structures of the cables 104, such as to cable shields of the cables 104 and/or drain wires of the cables 104. In an exemplary embodiment, the ground bus 300 is connected to the cable shields and/or the drain wires using a conductive gasket, conductive adhesive, conductive epoxy, a conductive tape or braid, conductive foam, soldering, and the like. In an exemplary embodiment, the ground bus 300 is soldered to the circuit card 132. For example, solder posts or solder tabs are provided at the bottom of the ground bus 300 for soldering to the circuit card 132 at termination areas. In various embodiments, multiple ground busses 300 may be provided.
In an exemplary embodiment, the cable card assembly 130 includes multiple rows and multiple columns of cables 104. The cables 104 may be grouped together, such as in 3×4 arrangements. In the illustrated embodiment, the cables 104 are terminated to one side of the circuit card 132, such as the top side of the circuit card 132. However, the cables 104 may additionally or alternatively be terminated to the bottom side of the circuit card 132. Each row of cables 104 includes the corresponding ground bus 300. The ground busses 300 may be similar for each of the rows. However, the ground busses 300 may be sized and shaped differently to accommodate a stacking/overlapping situation.
The circuit card 132 extends between a cable end 134 (for example, top portion) and a mating end 136 (for example, bottom portion). Other arrangements are possible in alternative embodiments, such as having the mating end 136 at a front edge of the circuit card 132 to plug into a card slot. The cable end 134 may additionally or alternatively be provided at the bottom portion in other alternative embodiments. The cables 104 are configured to be coupled to the circuit card 132 at the cable end 134. The cables 104 extend rearward from the circuit card 132 in the illustrated embodiment. The circuit card 132 includes an upper surface 140 and a lower surface 142. The cables 104 are connected to the circuit card 132 at the upper surface 140 in the illustrated embodiment. The lower surface 142 is configured to be mated to the second electrical connector 106 in the illustrated embodiment.
The circuit card 132 includes circuit conductors 144 (shown in
The ground bus 300 surrounds the ends of the cables 104. For example, the ends of the cables 104 are located in corresponding pockets 301 in the ground bus 300. The ground bus 300 is three-dimensional. The ground bus 300 is configured to surround all sides of the ends of the cables 104 (for example, the cable top, the cable bottom, the cable right side and the cable left side). The ground bus 300 is electrically connected to the cables 104 (for example, the cable shield and/or drain wires). In an exemplary embodiment, the ground bus 300 is configured to engage and electrically connect to the cable shield of the cable on all sides (for example, the top, the bottom, the right side and the left side). The ground bus 300 is terminated to the circuit card 132. The ground bus 300 electrically commons the cables 104 with the circuit card 132. The ground bus 300 electrically commons the cables 104 with each other. The ground bus 300 provides electrical shielding for signals transmitted between the circuit card 132 and the cables 104. The ground bus 300 enhances electrical performance of the cable card assembly 130, such as by reducing cross talk.
The ground bus 300 includes a shell 302 manufactured from a conductive material, such as a metal material to provide electrical shielding. In various embodiments, the ground bus 300 may be a diecast component. In other various embodiments, the ground bus 300 may be a plated plastic or conductive polymer structure. In other various embodiments, the ground bus 300 may be a stamped and formed component. In an exemplary embodiment, the ground bus 300 is a multipiece structure. For example, the ground bus 300 includes one or more inner bus members 304 and one or more outer bus members 306 coupled to the inner bus member(s) 304. Optionally, one or more conductive gaskets may be provided at the interface(s) between the inner bus member(s) 304 and the outer bus member(s) 306. The inner bus member 304 is located between the outer bus members 306 and the circuit card 132. The ground bus 300 may be oriented such that the inner bus member 304 is a bottom bus member and the outer bus member 306 is a top bus member. However, other orientations are possible in alternative embodiments. The cables 104 are received between the inner bus member 304 and the outer bus member 306. For example, the pockets 301 may be formed by the inner and outer bus members 304, 306 and the cables 104 are received in the pockets 301 between the inner and outer bus members 304, 306.
The ground bus 300 extends between a front 312 and a rear 314. The rear 314 is configured to face the cables 104. The ground bus 300 extends between an inner end 316 and an outer end 318. The inner bus member 304 is at the inner end 316 and the outer bus member 306 is at the outer end 318. The cables 104 may extend from the outer end 318, such as toward the rear 314. The ground bus 300 may be oriented such that the inner end 316 is a bottom end and the outer end 318 is a top end. However, other orientations are possible in alternative embodiments. In various embodiments, the inner end 316 is at the bottom and is configured to face the circuit card 132. The inner end 316 may be mounted to the circuit card 132 to mechanically and electrically connect the ground bus 300 to the circuit card 132. In an exemplary embodiment, the inner end 316 is configured to be soldered to the circuit card 132.
The inner bus member 304 is manufactured from a conductive material, such as a metal material. In various embodiments, the inner bus member 304 is a diecast member. In other various embodiments, the inner bus member 304 may be a plated plastic member. In the illustrated embodiment, the inner bus member 304 is shown as a single unit between the front 312 and the rear 314 configured to accommodate multiple rows of the cables 104. However, in alternative embodiments, the inner bus member 304 may be a multi-piece structure, such as including a stack of bus elements arranged front to rear to accommodate corresponding rows of the cables 104.
The inner bus member 304 includes a base 340 extending between the front 312 and the rear 314. The base 340 includes sides 315 that extend between the front 312 and the rear 314. In an exemplary embodiment, the base 340 includes a plurality of openings 342 therethrough. The openings 342 form portions of the pockets 301. The base 340 includes separating walls 344 between the openings 342/pockets 301. The separating walls 344 surround the pockets 301. For example, the separating walls 344 extend along both sides of the pockets 301, extend along the fronts of the pockets 301 and extend along the rears of the pockets 301. The separating walls 344 provide shielding between the pockets 301. The separating walls 344 of the inner bus member 304 extend between a bottom or a lower surface 346 and a top or an upper surface 348. The bottom 346 is configured to face the circuit card 132. The outer bus members 306 (
In an exemplary embodiment, the base 340 includes cable cradles 350 configured to receive corresponding cables 104. The cable cradles 350 form portions of the pockets 301. The cable cradles 350 support the cables 104 for termination to the circuit card 132. The cable cradles 350 define a cable exit and control the cable exit direction for the cables 104. For example, the cable exit direction may be upward and rearward from the base 340, such as to elevate the cables 104 over the rearward rows of cables. In various embodiments, the cable exit direction may be approximately 45°. The cable cradles 350 provide support for the cables 104, such as to provide strain relief for the cables 104. The cable cradles 350 may form an area for electrical connection to the cable shield of the cable 104, such as along the bottom and sides of the cable shield.
In an exemplary embodiment, the inner bus member 304 includes shielding elements 352 extending along the upper surfaces 348 of the separating walls 344. The shielding elements 352 are used for positioning and/or shielding between the outer bus members 306. The shielding elements 352 are located between the pockets 301. The shielding elements 352 may be protrusions, such as lips or walls extending from the separating walls 344. In alternative embodiments, the shielding elements 352 may be grooves or slots formed in the separating walls 344. Other types of shielding elements may be used in alternative embodiments. The shielding elements 352 are sized and shaped to interact with complimentary elements of the outer bus members 306.
In an exemplary embodiment, the inner bus member 304 includes locating pins 354 extending from the separating walls 344. The locating pins 354 may extend upward from the upper surfaces 346 of the separating walls 344. The locating pins 354 are configured to interface with the outer bus members 306 to locate the outer bus members 306 relative to the inner bus member 304. For example, the locating pins 354 may be received in openings in the outer bus members 306 to align the outer bus members 306 with the inner bus member 304. The locating pins 354 may be press-fit into the outer bus members 306 to mechanically and electrically connect the outer bus member 306 to the inner bus member 304.
In an exemplary embodiment, the inner bus member 304 includes solder standoff posts 360 extending from the inner end 316. For example, the solder standoff posts 360 extend from the lower surface 364 to terminating ends 362 at distal ends of the solder standoff posts 360. The solder standoff posts 360 are configured to be terminated to the circuit card 132. In an exemplary embodiment, the solder standoff posts 360 are soldered to the circuit card 132. Solder balls may be provided at the terminating ends 362. In an exemplary embodiment, the solder standoff posts 360 are configured to hold the inner end 316 elevated from the surface of the circuit card. The solder standoff posts 360 may hold the inner end 316 off the circuit card 132 to ensure solder fillets up the solder standoff posts 360 and does not wick away from one post to another post to ensure good electrical connections at each of the solder standoff posts 360.
In an exemplary embodiment, the solder standoff posts 360 surround each pocket 301. For example, the solder standoff posts 360 extend from the inner end 316 along each of the pocket front, the pocket rear, the first pocket side, and the second pocket side of each pocket 301. The solder standoff posts 360 extend from each of the separating walls 344. In an exemplary embodiment, each separating wall 344 includes a plurality of the solder standoff posts 360. For example, a plurality of the solder standoff posts 360 are provided forward of each opening 342; a plurality of the solder standoff posts 360 are provided rearward of each opening 342; a plurality of the solder standoff posts 360 are provided along the right side of each opening 342; and a plurality of the solder standoff posts 360 are provided along the left side of each opening 342. The solder standoff posts 360 form a picket fence type of shielding structure surrounding each pocket 301.
In an exemplary embodiment, the solder standoff posts 360 are cylindrical. However, the solder standoff posts 360 may have other shapes. In an exemplary embodiment, each solder standoff posts 360 has a post width (for example, a diameter). The solder standoff posts 360 are separated by gaps 364. In an exemplary embodiment, the solder standoff posts 360 are closely spaced. For example, the gaps 364 have gap widths less than three times the post width. Optionally, the gap widths may be approximately equal to the post widths. The gap widths may be sufficiently small to reduce or minimize cross talk and return loss for efficient operation at a target frequency. In various embodiments, the solder standoff posts 360 may be spaced apart at distances to prevent crosstalk at a target frequency, such as approximately 67 GHz. In various embodiments, the gap widths may be approximately 0.5 mm. The gap widths may be approximately 1.0 mm. The gap widths may be narrower or wider in alternative embodiments for other target frequencies.
The outer bus member 306 includes a cap 320 having a base wall 322 and cable covers or hoods 324. The cable covers 324 cover the ends of the cables 104. The cable covers 324 may be angled to accommodate the cables 104 extending outward from the circuit card 132, such as at an angle between 30° and 60°. The base wall 322 is provided at the bottom or inner end of the outer bus member 306. The base wall 322 is configured to be coupled to the inner bus member 304 (shown in
In an exemplary embodiment, the outer bus member 306 includes shielding elements 326 extending from the base wall 322 of the cap 320. The shielding elements 326 are used for positioning and/or shielding between the outer bus member 306 and the inner bus member 304. The shielding elements 326 may interact with the shielding elements 352 of the inner bus member 304 to locate the outer bus member 306 relative to the inner bus member 304. The shielding elements 352 cause the base wall 322 to be non-planar, which provides surfaces for making connections to improve EMI shielding at the interface. In an exemplary embodiment, the cap 320 includes openings 328 in the base wall 322. The openings 328 receive the locating pins 354 (
In an exemplary embodiment, the circuit card 132 includes cable termination areas 145 at the upper surface 140. The cable termination areas 145 are configured to receive the corresponding cables 104. In an exemplary embodiment, the cable termination areas 145 are arranged in rows and columns. The circuit conductors 144 are arranged in the cable termination areas 145. For example, the circuit conductors 144 includes signal pads 146 and ground pads 148 in the cable termination areas 145. The signal pads 146 and the ground pads 148 are provided at the upper surface 140. The ground pads 148 are connected to the one or more ground planes 143 of the circuit card 132. The ground pads 148 are configured to be electrically connected to the corresponding solder standoff posts 360. For example, the solder standoff posts 360 may be soldered to the corresponding ground pads 148.
In an exemplary embodiment, the signal pads 146 are arranged in pairs. For example, each cable termination area 145 includes one pair of the signal pads 146. A solder mask 147 surrounds the signal pads 146 and/or the ground pads 148 to separate the circuit conductors 144 from each other. The individual ground pads 148 are isolated from each other and separated by barriers defined by the solder mask 147. In an exemplary embodiment, the ground pads 148 surround the pair of the signal pads 146. For example, the ground pads 148 form shield fences 149 around each pair of the signal pads 146. Each cable termination area 145 includes a corresponding shield fence 149. In an exemplary embodiment, the ground pads 148 completely surround the signal pads 146. For example, the ground pads 148 are located forward of the pair, rearward of the pair, along the right side of the pair, and along the left side of the pair. In an exemplary embodiment, multiple ground pads 148 are arranged along the front of the pair; multiple ground pads 148 are arranged along the rear of the pair; multiple ground pads 148 are arranged along the right side of the pair; and multiple ground pads 148 are arranged along the left side of the pair.
Each cable 104 includes at least one signal conductor and a shield structure providing electrical shielding for the at least one signal conductor. In an exemplary embodiment, the cables 104 are twin-axial cables. For example, each cable 104 includes a first signal conductor 150 and a second signal conductor 152. The signal conductors 150, 152 carry differential signals. The signal conductors 150, 152 are configured to be electrically connected to corresponding circuit conductors 144 of the circuit card 132. However, the cables 104 may include greater or fewer signal conductors in alternative embodiments, such as being a coaxial cable.
The cable 104 includes one or more insulators 154 surrounding the signal conductors 150, 152 and a cable shield 160 surrounding the insulators 154. The cable shield 160 provides circumferential shielding around the signal conductors 150, 152. The cable 104 includes a cable jacket 162 surrounding the cable shield 160. In various embodiments, the cable 104 includes one or more drain wires 164 electrically connected to the cable shield 160. In alternative embodiments, the cable 104 is provided without a drain wire.
In an exemplary embodiment, the cable jacket 162, the cable shield 160, and the insulators 154 may be removed (e.g., stripped) to expose portions of the signal conductors 150, 152 for termination to the circuit card 132 (or to the contact assembly). A portion of the cable shield 160 may be exposed and/or portions of the drain wires 164 may be exposed for termination to the ground bus 300. The exposed portions of the signal conductors 150, 152 are configured to be mechanically and electrically coupled (e.g., soldered) to corresponding circuit conductors 144 of the circuit card 132. The cable shield 160 does not extend along the exposed portions. However, the ground bus 300 extends along the exposed portions and provides shielding for the exposed portions. For example, the ground bus 300 may extend along the top, the bottom, and both sides of the cable 104. In an exemplary embodiment, the ground bus 300 physically engages, to electrically connect to, the cable shield 160 at multiple points of contact, such as along the top, the bottom and both sides of the cable shield 160. The ground bus 300 may be shaped and positioned relative to the exposed portions to control impedance along the signal paths. For example, the ground bus 300 may be shaped and positioned relative to the exposed portions to maintain a target impedance along the signal paths (for example, 50 Ohms, 75 Ohms, 100 Ohms, and the like).
During assembly, the inner bus member 304 is mounted to the circuit card 132. The pockets 301 of the ground bus 300 are aligned with the cable termination areas 145. The solder standoff posts 360 are mounted to the ground pads 148 of the circuit card 132. In an exemplary embodiment, each solder standoff post 360 is soldered to the corresponding ground pad 148, such as by a reflow soldering process. The solder standoff posts 360 hold the base 340 with the lower surface 142 elevated off of the upper surface 140 of the circuit card 132, which provides an air space around the cable termination areas 145. Each solder standoff post 360 is directly electrically connected to the circuit card 132, such as being soldered to the corresponding ground pad 148 to ensure a good electrical connection is made between the ground bus 300 and the ground plane of the circuit card 132 at all of the desired locations (for example, at a predetermined spacing).
The inner bus member 304 includes multiple rows of the openings 342, corresponding to the pockets 301, to receive the multiple rows of the cables 104. In an exemplary embodiment, a single inner bus member 304 is provided, which accommodates multiple rows and columns of the cables 104. The single inner bus member 304 is configured to be coupled to the circuit card 132 in a single assembly process (for example, a single reflow solder process), rather than coupling many individual cable shields around each individual cable 104.
During assembly, rows of the cables 104 are coupled to the circuit card 132, followed by coupling the corresponding outer bus member 306 to the inner bus member 304. As such, rows of the cables and outer bus members 306 may be stacked to form the cable card assembly 130. The outer bus members 306 may be connected to the inner bus member 304 by a press fit (interference fit), by soldering, using conductive adhesive, using conductive epoxy, using fasteners, or by other means. The outer bus members 306 shield or cover the tops of the cables 104. Each cable 104
The ground bus 300 is configured to provide shielding for the cables 104. For example, the inner bus member 304 and the outer bus members 306 cooperate to form the pockets 301 that receive the corresponding cables 104. Optionally, each pocket 301 may receive a single (for example, different) cable 104. The ground bus 300 includes multiple rows of the pockets 301 to receive the multiple rows of the cables 104. The cables 104 are received in the cable cradles 350 and the ends of the cables 104 are received in the openings 342 for termination to the circuit card 132. The separating walls 344 provide shielding between the pockets 301 and the cables 104 in the different pockets 301.
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 invention 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 scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 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.
