Patent Application
20140206221
The subject matter herein relates generally to electrical connector systems using daughtercard and backplane connectors.
Due to their favorable electrical characteristics, coaxial cables and connectors have grown in popularity for interconnecting electronic devices and peripheral systems. The connectors include an inner conductor coaxially disposed within an outer conductor, with a dielectric material separating the inner and outer conductors. A typical application utilizing coaxial cable connectors is a radio-frequency (RF) application having RF connectors designed to work at radio frequencies in the VLF through SHF range. RF connectors are typically used with coaxial cables and are designed to maintain the shielding that the coaxial design offers.
In a daughtercard/backplane application, known RF connectors typically use multiple RF contact assemblies in a single housing. The contact assemblies on the daughtercard side are float mounted and attached to free cables while the backplane contact assemblies are fixed coaxial cable assemblies. One drawback to such conventional arrangement is that both sets of the contact assemblies are cable mounted, which restricts the design density on the removable daughtercard.
A need remains for an electrical connector system that uses a configuration of daughtercard and backplane connectors that afford greater packaging flexibility for system designers.
In one embodiment, an electrical connector system is provided having a backplane connector and a daughtercard connector coupled to the backplane connector. The backplane connector includes a housing holding a plurality of backplane contact assemblies that are movable relative to the housing and each have a center contact and an outer shell surrounding the center contact configured to be terminated to coaxial cables. The daughtercard connector includes a housing holding a plurality of daughtercard contact assemblies coupled to corresponding backplane contact assemblies. The daughtercard contact assemblies are configured to be directly terminated to a daughtercard circuit board.
Optionally, the backplane contact assemblies may be spring loaded within the housing of the backplane connector to allow relative movement between the backplane contact assemblies and the housing of the backplane connector. The backplane contact assemblies may each have a spring surrounding the outer shell with a first end of the spring engaging the housing of the backplane connector and a second end of the spring engaging a retaining washer coupled to the shell. The spring may be captured between the housing of the backplane connector and the retaining washer and may be compressible to allow relative movement between the backplane contact assemblies and the housing of the backplane connector. Optionally, the backplane contact assemblies may be spring biased against corresponding daughtercard contact assemblies to maintain electrical connection therewith.
Optionally, the backplane contact assemblies may each have mating interfaces internal of the housing of the backplane connector. The housing of the backplane connector may include bores receiving corresponding backplane contact assemblies and portions of corresponding daughtercard contact assemblies such that mating interfaces of the backplane contact assemblies and mating interfaces of the daughtercard contact assemblies are positioned within corresponding bores. Optionally, the daughtercard contact assemblies may be directly mated with corresponding backplane contact assemblies within the housing of the backplane connector. The backplane contact assemblies float within the housing of the backplane connector to align with and maintain electrical connection with the daughtercard contact assemblies.
Optionally, the electrical connector system may include interconnects between corresponding backplane contact assemblies and daughtercard contact assemblies that create direct electrical paths between the backplane contact assemblies and the daughtercard contact assemblies. A conductive gasket that provides EMI/EMP shielding may be positioned between and directly engages both the housing of the backplane connector and the housing of the daughtercard connector.
Optionally, the daughtercard contact assemblies may include contacts configured to be terminated to the daughtercard circuit board. The contacts may be held within the housing of the daughtercard connector and fixed in place relative to the housing of the daughtercard connector. The daughtercard contact assemblies may each include a mating contact and a board contact. The mating contact may be provided at a mating end of the housing of the daughtercard connector and the board contact may be provided at a mounting end of the housing of the daughtercard connector and mounted to the daughtercard circuit board. The board contact may be coupled to the mating contact within corresponding bores of the housing of the daughtercard connector. The board contact may extend from the housing of the daughtercard connector and may be terminated to the daughtercard circuit board.
Optionally, the housing of the daughtercard connector may include bores therein extending between mating and mounting ends of the housing of the daughtercard connector. The mating and mounting ends may be generally perpendicular to one another. The bores may include first and second segments oriented generally perpendicular to one another. The first segments may extend between the mating end and the second segment, while the second segment may extend between the mounting end and the first segment. The daughtercard contact assemblies may each include a mating contact received in the corresponding first segment and a board contact received in the corresponding second segment. The board contact may be coupled to the mating contact within corresponding bores generally at the intersection between the first and second segments.
Optionally, the electrical connector system may further include a second backplane connector, a backplane with the first and second backplane connectors coupled to the backplane, and a second daughtercard connector configured to be coupled to a second daughtercard circuit board. The first daughtercard connector and corresponding daughtercard circuit board may be mated with the first backplane connector, and the second daughtercard connector and corresponding second daughtercard circuit board may be mated with the second backplane connector.
In another embodiment, an electrical connector system is provided having a backplane connector including a housing having first and second faces and a bore extending between the first and second faces. The backplane connector includes a backplane contact assembly positioned in the bore of the housing and having a mating end being positioned internal to the bore and a cable end extending from the second face of the bore. The backplane contact assembly floats within the bore such that the mating end is movably positionable relative to the first and second faces. The electrical connector system includes a daughtercard connector including a housing having a mating end and a mounting end. The mating end is mated with the first face of the housing of the backplane connector. The mounting end is configured to be mounted to a daughtercard circuit board. The mounting end is generally perpendicular to the mating end. The housing has bores extending between the mating and mounting ends, and the daughtercard connector includes a daughtercard contact assembly positioned in the bores and having a mating contact provided at the mating end and a board contact provided at the mounting end. The board contact is coupled to the mating contact within at least one of the bores. The board contact extends from the housing and is configured to be terminated to the daughtercard circuit board.
In an exemplary embodiment, a plurality of the backplane connectors 12 may be mounted to the backplane 16 for interfacing with different daughtercards 18 and corresponding daughtercard connectors 14. For example, in a server/blade system, the backplane 16 may be mated with a plurality of blades defined by the daughtercards 18 and corresponding daughtercard connectors 14.
In an exemplary embodiment, the backplane and daughtercard connectors 12, 14 define radio frequency (RF) modules configured to convey multiple RF signals. In the illustrated embodiment, the daughtercard connector 14 is direct mounted to the daughtercard circuit board 18 (e.g. the conductor of the daughtercard connector 14 is directly connected to the daughtercard circuit board 18, such as by through-hole mounting, surface mounting, soldering and the like). In the illustrated embodiment, the backplane connector 12 includes a plurality of backplane contact assemblies 20 that are each cable mounted to corresponding coaxial cables 22 extending from the back end of the backplane connector 12.
Guides 24, 26 are used to guide mating of the daughtercard connector 14 with the backplane connector 12. For example, the guide 24 may be a pin received in a receptacle defined by the guide 26. The guides 24, 26 may allow blind mating of the daughtercard connector 14 with the backplane connector 12, such as by aligning the daughtercard connector 14 with the backplane connector 12 prior to mating.
The housing 100 includes a mating end 110 at a front of the housing 100 and a mounting end 112 at a bottom or side of the housing 100. The mating and mounting ends 110, 112 are generally perpendicular and allow the daughtercard circuit board 18 to be oriented perpendicular to the backplane 16 (shown in
The daughtercard contact assemblies 102 define shielded RF contacts and generally include a center conductor 130 (shown in
The daughtercard connector 14 includes a plurality of ground pins 116 extending from the mounting end 112. The ground pins 116 are configured to be terminated to the daughtercard circuit board 18, such as by through hole mounting to corresponding ground vias in the daughtercard circuit board 18. The ground pins 116 electrically connect the housing 100 to a ground plane of the daughtercard circuit board 18. Other types of features may be used to electrically connect the housing 100 to the daughtercard circuit board 18 in alternative embodiments. Multiple ground pins 116 surround each of the center conductors 130 to enhance electrical shielding around the center conductors 130. Any number of ground pins 116 may be used. Optionally, some of the ground pins 116 may be shared by adjacent center conductors 130.
The housing 100 includes a plurality of bores 120 extending therethrough between the mating end 110 and the mounting end 112. The center conductors 130 are configured to be received in and routed through the bores 120. At the mating end 110, the bores 120 are sized and shaped to receive the front shells 114 (shown in
Each daughtercard contact assembly 102 includes the front shell 114, the center conductor 130 and insulators 132 used to support the center conductor 130 in the housing 100 and/or the front shell 114. The insulators 132 are manufactured from a dielectric material, such as a plastic material. The insulators 132 position the center conductor 130 at a predetermined spacing from the housing 100 and/or the front shell 114, such as to control the impedance along the signal path.
In an exemplary embodiment, the center conductor 130 is formed from two contact pieces that are mechanically and electrically coupled together within the housing 100. The center conductor 130 includes a mating contact 134 and a board contact 136. The mating contact 134 is provided at the mating end 110 of the housing 100. The mating contact 134 is configured to be electrically connected to the backplane connector 12 (shown in
In an exemplary embodiment, the board contact 136 is oriented generally perpendicular to the mating contact 134. The board contact 136 is coupled to the mating contact 134 within corresponding bore 120 generally at the intersection between the first and second segments 122, 124. The board contact 136 is coupled to the mating contact 134 using a pin and socket type of connection, however other types of interfaces may be used in alternative embodiments to mechanically and electrically connect the board contact 136 and the mating contact 134.
During assembly, the front shell 114, insulators 132 and contacts 134, 136 may be loaded into the bores 120 and held in the housing 100 once positioned. For example, the front shell 114 may be loaded into the housing 100 through the mating end 110. Some of the insulators 132 are loaded into the front shells 114, some of the insulators 132 are loaded into the first segments 122 of the bores 120 and some of the insulators 132 are loaded into the second segments 124 of the bores 120. The insulators 132 may be preloaded into position prior to loading the contacts 134, 136 into the corresponding insulators 132, or alternatively, the contacts 134, 136 may be loaded into the insulators 132 and then loaded as a unit into the housing 100.
The housing 200 includes a mating end 210 at a front of the housing 200 and a mounting end 212 at a rear of the housing 200. The mating end 210 is configured to be mated to the daughter card connector 14 (shown in
The housing 200 forms part of an outer shield for the backplane contact assemblies 20 by surrounding the center contacts 250 (shown in
The shell 240 is generally cylindrical in shape. A flange 260 extends radially outward from the shell 240. The flange 260 is positioned proximate the cable end 246. In the illustrated embodiment, the flange 260 is positioned a distance from the mating end 244. The flange 260 includes a forward facing surface 264 and a rear facing surface 266. The surfaces 264, 266 are generally perpendicular with respect to the longitudinal axis 242.
The shell 240 is tapered or stepped at the mating end 244 such that a shell diameter at the mating end 244 is smaller than along other portions of the shell 240. The shell 240 includes a tip portion 274 configured to be received within the front shell 114 of the daughtercard contact assembly 102 (both shown in
The washer 256 includes a ring-shaped body 300 having a radially inner surface 302 and a radially outer surface 304. The washer 256 includes a forward facing surface 306 and a rear engagement surface 308.
The spring 254 has a helically wound body 320 extending between a front end 322 and a rear end 324. The rear end 324 faces the forward facing surface 264 of the flange 260. The spring 254 is loaded over the mating end 244 and concentrically surrounds a portion of the shell 240. The spring 254 has a spring diameter that is greater than the shell diameter. The spring 254 is compressible axially.
During assembly, the retaining washer 256 is loaded onto the mating end 244 of the shell 240 and holds the spring 254 in position relative to the shell 240. The rear engagement surface 308 of the washer 256 engages the front end 322 of the spring 254. Optionally, the washer 256 may at least partially compress the spring 254 such that the spring is biased against the washer 256.
In an exemplary embodiment, as shown in
The contact 250 is held within the shell cavity 248 by the dielectric body 252. The contact 250 includes a mating end 350 and a terminating end 352. The mating end 350 is configured to mate with the corresponding mating contact 134 (shown in
The backplane contact assemblies 20 are illustrated within the bores 220 of the housing 200. The spring 254 is positioned between the housing 200 and the retaining washer 256. The rear end 324 of the spring 254 engages the lip 222 extending into the bore 220 at the mounting end 212 of the housing 200. The spring is compressed between the lip 222 and the retaining washer 256. The spring 254 may be compressed to allow the backplane contact assembly 20 to move relative to the housing 200. The backplane contact assembly 20 is able to float within the housing 200, such as during mating with the daughtercard connector 14. Optionally, the backplane contact assembly 20 may be capable of floating in 3-dimensions (e.g. front to back; top to bottom; and/or side to side). The floating may allow proper alignment with the daughtercard connector 14 during mating. The spring 254 maintains spring pressure in a forward direction against the daughtercard connector 14 to ensure mating engagement between the center contact 250 and the mating contact 134.
The housing 200 is illustrated mounted to the backplane 16. In the illustrated embodiment, the rear of the mounting end 212 is mounted to the backplane 16, while a portion of each backplane contact assembly 20 extends through corresponding openings 402 in the backplane 16. The flange 260 is captured at the back side of the backplane 16. The forward facing surface 264 of the flange 260 faces the backplane 16. The spring pressure of the spring 254 may hold the flange 260 against the backplane 16. The flange 260 may be pressed away from the backplane 16 when the spring 254 is compressed, such as during mating with the daughtercard connector 14.
The housing 500 includes a mating end 510 at a front of the housing 500 and a mounting end 512 at a rear of the housing 500. The mounting flange 506 is provided at the mounting end 512. The mounting end 512 is configured to be mounted to the backplane 16. The mating end 510 is configured to be mated to the daughter card connector 14 (shown in
The housing 500 forms part of an outer shield for the backplane contact assemblies 504. The housing 500 includes a plurality of bores 520 extending therethrough between the mating end 510 and the mounting end 512. The backplane contact assemblies 504 are configured to be received in corresponding bores 520. In an exemplary embodiment, the bores 520 are cylindrical and pass straight through the housing 500 with a flange or lip 522 proximate to the mounting end 512 used to hold the backplane contact assemblies 504 in the bores 520.
In an exemplary embodiment, interconnects 530 are positioned in the bores 520 between corresponding backplane contact assemblies 504 and daughtercard contact assemblies 102. The interconnects 530 create direct electrical paths between the backplane contact assemblies 504 and the daughtercard contact assemblies 102. The interconnect 530 includes an interconnect contact 532 having opposed mating ends 534, 536 that interface with the mating contact 134 and a center contact 538 of the backplane contact assembly 504. In the illustrated embodiment, the mating ends 534, 536 are sockets configured to receive pins defined at mating ends of the mating contact 134 and the center contact 538. Alternatively, the center contact 538 may be directly coupled to the mating contact 134 in alternative embodiments.
The backplane contact assembly 504 includes an outer shell 540 and an insulator 542 held within the outer shell 540. The insulator 542 holds the center contact 538. The outer shell 540 provides shielding for the center contact 538. A spring 544 surrounds the outer shell 540 and allows relative movement of the backplane contact assembly 504 with respect to the housing 500. The backplane contact assembly 504 is terminated to an end of a cable 546, which extends from the backplane connector 502 beyond the backplane.
In an exemplary embodiment, a retainer 550 is used to hold the backplane contact assembly 504 within the housing 500. The retainer 550 is secured to the lip 522. The retainer 550 includes an opening 552 through which a portion of the backplane contact assembly 504 extends. The backplane contact assembly 504 is movable within the opening 552. The retainer 550 is used to retain the spring 544 and the spring is compressible against the retainer 550.
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, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
