Patent Application
20180026400
The subject matter herein relates generally to an electrical connector having signal contacts and associated ground shields.
Some electrical connector systems utilize receptacle and header connectors to interconnect two circuit boards, such as a motherboard and daughtercard. When the connectors are mated, the circuit boards may be arranged parallel to one another. Such connector systems can be complex and difficult to manufacture. The connectors can have ground shields that are designed to shield signal contacts from other signal contacts within the connectors. The ground shields may be electrically commoned at the circuit boards, but a lack of commoning of the ground shields in a region between the circuit boards reduces the shielding effectiveness and therefore inhibits electrical performance of the connector system. For example, gaps between adjacent ground shields within the connectors may allow electrical resonance that interferes with signal transmission, thus reducing signal integrity. Such electrical interference is typically exacerbated by increasing signal transmission speeds through the connector assembly.
A need remains for an electrical connector having enhanced ground shielding that improves electrical performance.
In one embodiment, an electrical connector is provided that includes a housing and contact assemblies. The housing extends between a mating end and a mounting end. The housing includes shroud walls and a base having a front side and a rear side. The rear side of the base defines the mounting end. The shroud walls extend from the base to the mating end. The front side of the base and the shroud walls define a cavity configured to receive a mating connector therein. The base is electrically conductive. The base has chambers extending therethrough. The chambers are defined by chamber walls that extend from the front side to the rear side of the base. The contact assemblies are received in the chambers of the base. Each contact assembly has a signal pod surrounded on at least two sides by a ground shield having interior sides and exterior sides. The signal pod includes a dielectric body holding a pair of signal contacts. The dielectric body engages the interior sides of the ground shield to electrically insulate the signal contacts from the ground shield. The exterior sides of the ground shield engage the chamber walls of the base to electrically connect the ground shield to the base.
In another embodiment, an electrical connector is provided that includes a housing and contact assemblies. The housing has a base extending between a front side and a rear side. The base is electrically conductive. The base has chambers extending therethrough. The chambers are defined by chamber walls that extend from the front side to the rear side of the base. The contact assemblies are received in the chambers of the base. Each contact assembly has a signal pod surrounded on at least two sides by a ground shield having interior sides and exterior sides. The signal pod includes a dielectric body holding a pair of signal contacts. The dielectric body engages the interior sides of the ground shield to electrically insulate the signal contacts from the ground shield. The exterior sides of the ground shield engage the chamber walls of the base to electrically connect the ground shield to the base. The exterior sides of the ground shield engage the chamber walls at multiple contact locations along a height of the base between the front side and the rear side to electrically connect the ground shield to the base at the multiple contact locations.
In an exemplary embodiment, the circuit boards 106, 108 are oriented parallel to one another and spaced apart from one another with the connectors 102, 104 therebetween. The circuit boards 106, 108 and connectors 102, 104 define a mezzanine arrangement where the circuit boards 106, 108 and connectors 102, 104 are stacked. The circuit boards 106, 108 may be oriented horizontally with the connectors 102, 104 defining vertical connectors between the horizontal circuit boards 106, 108. The signal contacts of the connectors 102, 104 pass in-line or linearly therethrough in a vertical direction. Other orientations of the circuit boards 106, 108 are possible in alternative embodiments. For example, one or both of the connectors 102, 104 may be a right angle connector instead of an in-line connector. In another embodiment, one or both of the connectors 102, 104 may be cable-mounted to an electrical cable instead of mounted to a circuit board.
The receptacle connector 102 includes a receptacle housing 120 that holds a plurality of receptacle signal contacts (not shown). The receptacle signal contacts are electrically shielded by receptacle ground contacts (not shown). The receptacle housing 120 extends between a mating end 128 and a mounting end 130. In the illustrated embodiment, the mounting end 130 is substantially parallel to the mating end 128. The receptacle housing 120 includes a plurality of signal contact openings 132 and a plurality of ground contact openings 134 at the mating end 128. The receptacle signal contacts are disposed in the corresponding signal contact openings 132, and the receptacle ground contacts are disposed in the ground contact openings 134. The signal contact openings 132 receive corresponding header signal contacts 144 therein when the receptacle and header connectors 102, 104 are mated to allow the header signal contacts 144 to mate with the receptacle signal contacts. The ground contact openings 134 receive header ground shields 146 therein when the receptacle and header connectors 102, 104 are mated to allow the header ground shields 146 to mate with the receptacle ground contacts.
The receptacle housing 120 may be manufactured from a dielectric material, such as a plastic material, that provides electrical insulation between the signal contact openings 132 and the ground contact openings 134. Therefore, the receptacle housing 120 may electrically insulate the receptacle signal contacts and the header signal contacts 144 in the signal contact openings 132 from the receptacle ground contacts and the header ground shields 146 in the ground contact openings 134. The receptacle signal contacts protrude beyond the mounting end 130 of the receptacle housing 120 for electrically terminating (for example, electrically connecting in direct mechanical engagement) to the first circuit board 106.
The header connector 104 includes a header housing 138 extending between a mating end 150 and an opposite mounting end 152 that is mounted to the second circuit board 108. Optionally, the mounting end 152 may be substantially parallel to the mating end 150. The header housing 138 includes a base wall or housing base 148, referred to herein as a base 148, that has a front side 112 and an opposite rear side 114. The rear side 114 of the base 148 may define the mounting end 152 of the header housing 138. The rear side 114 faces the circuit board 108. The header signal contacts 144 and the header ground shields 146 are held by the base 148. The signal contacts 144 and ground shields 146 extend from the base 148 to be received in the respective signal contact openings 132 and ground contact openings 134 of the receptacle housing 120 when the connectors 102, 104 are mated. The header signal contacts 144 and the header ground shields 146 have terminating ends that extend through the base wall 148 and are mounted to the circuit board 108.
In one or more embodiments described herein, the header housing 138 is fully or at least partially electrically conductive. For example, the base 148 is electrically conductive due to being composed entirely of one or more metals, being composed of a non-conductive core material that is coated in a layer of metal, being composed of a lossy material having metal particles embedded in a non-conductive material, being composed of a conductive polymer material, being composed of a carbon-filled polymer, or the like. The electrically conductive base 148 engages the header ground shields 146 held in the base 148 to electrically common the header ground shields 146 with one another. The header signal contacts 144 are electrically insulated from the electrically conductive base 148 to avoid potential short-circuits. Electrically commoning the ground shields with one another along the base 148 of the housing 138 may improve the shielding effectiveness and, as a result, may provide enhanced signal performance relative to known connector systems.
In an embodiment, the header housing 138 also includes shroud walls 140 that extend from the base 148 and define the mating end 150 of the housing 138. The shroud walls 140 and the front side 112 of the base 148 define a cavity 142. For example, the shroud walls 140 define sides of the cavity 142 and the base 148 defines an end or bottom of the cavity 142. The header signal contacts 144 and ground shields 146 extend from the base 148 into the cavity 142. The receptacle connector 102 is received in the cavity 142 through the mating end 150. The receptacle housing 120 may engage the shroud walls 140 to guide the receptacle connector 102 into the cavity 142.
The pair 158 of signal contacts 144 may be used to convey differential signals. The signal contacts 144 may extend generally parallel to each other. The signal contacts 144 are composed of a conductive material, such as one or more metals like copper, aluminum, silver, or the like. The signal contacts 144 may be stamped and formed.
The signal contacts 144 each have a mating segment 160, a contact tail 162, and an intermediate segment 161 between the mating segment 160 and the tail 162. The mating segment 160 extends to a distal end 164 of the signal contact 144 and is configured to engage a corresponding receptacle signal contact (not shown) of the receptacle connector 102 (shown in
The contact tails 162 of the signal contacts 144 are configured to terminate to the circuit board 108 (shown in
The dielectric body 156 is composed of a dielectric material, such as one or more plastics. The dielectric body 156 surrounds and encases the intermediate segments 161 of the signal contacts 144 to define the signal pod 154. The dielectric body 156 holds the signal contacts 144 in fixed positions relative to each other and the dielectric body 156. The dielectric body 156 holds the signal contacts 144 in the pair 158 apart from each other such that the signal contacts 144 do not engage one another. In an embodiment, the dielectric body 156 may be formed prior to engaging the signal contacts 144, such as via a molding process. For example, the dielectric body 156 defines two apertures 157 that extend through the dielectric body 156 between a front end 163 and a rear end 170 of the dielectric body 156. Each signal contact 144 is loaded into one of the apertures 157 during an assembly process. In an alternative embodiment, the dielectric body 156 may be formed in situ on the signal contacts 144 via overmolding. The shape of the dielectric body 156 is optionally a rectangular prism or parallelepiped, with four sides 172 extending between the front and rear ends 163, 170, but the dielectric body 156 may have other shapes in alternative embodiments. In an embodiment, the dielectric body 156 includes one or more crush ribs 174 along the sides 172. The crush ribs 174 are configured to provide an interference fit with the ground shield 146 of the corresponding contact assembly 153. In an embodiment, the dielectric body 156 includes a ledge 159 that protrudes from at least one of the sides 172. In the illustrated embodiment, the dielectric body 156 includes one ledge 159 that extends the length of the dielectric body 156 between the front end 163 and the rear end 170. The ledge 159 is located generally centrally along a width of a side 172A that is not covered by the ground shield 146. The ledge 159 may be used for aligning and retaining the contact assembly 153 relative to the base 148 of the housing 138 during assembly of the header connector 104.
When the signal pod 154 is complete (for example, assembled or formed), the mating segments 160 of the signal contacts 144 extend from the front end 163 of the dielectric body 156, the contact tails 162 extend from the rear end 170 of the dielectric body 156, and the intermediate segments 161 are disposed within the dielectric body 156. The signal contacts 144 within the dielectric body 156 are broadside-coupled in an embodiment, such that one of the broad sides 166 of one signal contact 144 faces an opposing one of the broad sides 166 of the other signal contact 144 in the pair 158. Alternatively, the signal contacts 144 may be edgeside-coupled or may have another orientation in the signal pod 154.
The ground shield 146 extends between a mating end 176 and a terminating end 178. In the illustrated embodiment, the ground shield 146 has a center wall 180 and two side walls 182 that extend from respective edges 184 of the center wall 180. The center wall 180 and the side walls 182 are generally planar. The side walls 182 may extend generally parallel to each other in a common direction from the center wall 180. Thus, the ground shield 146 has a C-shaped cross-section defined by a plane perpendicular to the center wall 180 and the two side walls 182. Optionally, the side walls 182 may be oriented at approximately right angles relative to a plane of the center wall 180. The ground shield 146 may be stamped and formed from a sheet of metal. For example, the center wall 180 may be formed integral to the side walls 182, such that the side walls 182 are bent out of plane from the center wall 180. In an alternative embodiment, the ground shield 146 may have an L-shaped cross-section defined by the center wall 180 and one side wall 182. In another alternative embodiment, the ground shield 146 may have a rectangular or box-shaped cross-section defined by two center walls 180 and the two side walls 182.
The ground shield 146 includes contact tails 186 extending from rear edges 188 of the center wall 180 and side walls 182 to the terminating end 178. The contact tails 186 in the illustrated embodiment are compliant pins configured to be through-hole mounted to the circuit board 108 (shown in
The center wall 180 and the side walls 182 of the ground shield 146 have interior sides 190 and exterior sides 192. The interior sides 190 of the walls 180, 182 define a channel 194 configured to receive a corresponding signal pod 154 therein. The exterior sides 192 face away from the channel 194. The ground shield 146 in the illustrated embodiment includes multiple protrusions 195 along the center wall 180 and the side walls 182. The protrusions 195 may be bumps, bulges, or the like that extend out from the plane of the respective walls 180, 182. Some protrusions 195 are disposed along the interior side 190 of a respective wall 180, 182, and other protrusions 195 are disposed along the exterior side 192. The protrusions 195 are located at different heights (or lengths) along the ground shield 146 between the mating and terminating ends 176, 178. In an embodiment, the protrusions 195 are clustered in a region of the ground shield 146 that is more proximate to the rear edges 188 of the walls 180, 182 than to the mating end 176.
The housing 138 is oriented in the illustrated embodiment such that the mating end 150 faces upward. The base 148 extends a length between opposite first and second ends 202, 204. The base 148 extends a width between opposite first and second edge sides 206, 208. In the illustrated embodiment, the housing 138 includes two shroud walls 140 that extend from the edge sides 206, 208. The shroud walls 140 define sides of the cavity 142. The cavity 142 is open along the first and second ends 202, 204 of the base 148. In an alternative embodiment, the housing 138 may include additional shroud walls extending along the ends 202, 204 to fully-enclose a perimeter of the cavity 142. In another alternative embodiment, the housing 138 may include only one or no shroud walls 140.
The base 148 defines chambers 210 extending through the base 148. The chambers 210 are sized and shaped to each receive a contact assembly 153 therein. Thus, the signal pod 154 and the ground shield 146 of each contact assembly 153 are commonly received in the same chamber 210. The chambers 210 are defined by chamber walls 212. The chamber walls 212 and the chambers 210 extend fully through the base 148 between the front and rear sides 112, 114.
The base 148 of the housing 138 is electrically conductive. In an embodiment, the base 148 may be composed entirely of one or more metals. For example, the base 148 may be a solid (or hollow) metal that is formed via die-casting or a different molding process. In another embodiment, the base 148 may be composed of a non-conductive core material, such as one or more plastics, that is coated in a layer of one or more metals. For example, the metal layer that coats the non-conductive core material may be applied via electro-plating, physical vapor deposition (PVD), dipping, spraying, painting, or the like. In yet another embodiment, the base 148 may be composed of an electrically lossy material that includes metal particles (for example, flakes, powder, shavings, or the like) embedded and dispersed in a non-conductive material, such as one or more plastics. The base 148 may be molded into shape using the lossy material to provide the electrical conductivity. In another embodiment, the base 148 may be composed of a conductive polymer, which is an organic polymer that conducts electricity.
The portion of the base 148 that includes chambers 210 is electrically conductive. Thus, the chamber walls 212 are electrically conductive. The entire structure of the base 148 may be electrically conductive, or alternatively one or more end portions of the base 148 are not electrically conductive. The shroud walls 140 of the housing 138 may be electrically conductive. For example, the housing 138 may have a unitary, one-piece structure that is entirely electrically conductive. Alternatively, the shroud walls 140 are not electrically conductive.
In an embodiment, some of the chamber walls 212 are divider walls or septums that define portions of multiple chambers 210. For example, at least some of the frame walls 262 extend between and define portions of two adjacent chambers 210 in one row 220. Thus, a left surface 266 of one of the frame walls 262 defines a right side of a left chamber 210A, and a right surface 268 of the same frame wall 262 defines a left side of a right chamber 210B. The frame walls 262 that define the first and second ends 202, 204 of the base 148 do not extend between and define portions of multiple chambers 210 in the same row 220. Furthermore, at least some of the cross walls 264 extend between and define portions of two adjacent chambers 210 in one column 218. Thus, a top surface 270 of one of the cross walls 264 defines a bottom side of a top chamber 210C, and a bottom surface 272 of the same cross wall 264 defines a top side of a bottom chamber 210D. The cross walls 264 that define the first and second edge sides 206, 208 of the base 148 do not extend between and define portions of multiple chambers 210 in the same column 218. As used herein, relative or spatial terms such as “front,” “rear,” “top,” “bottom,” “first,” “second,” “left,” and “right” are only used to distinguish the referenced elements and do not necessarily require particular positions or orientations relative to the surrounding environment of the header connector 104 (shown in
In an embodiment, at least one of the chamber walls 212 defining each of the chambers 210 includes a groove-shaped recess 274 that is open to the chamber 210. In the illustrated embodiment, the recesses 274 are defined along the top surfaces 270 of the cross walls 264 that extend between two chambers 210 in the same column 218. The recesses 274 are configured to receive the ledges 159 (shown in
The base 148 further defines a row 232 of orphan slots 234 between the first edge side 206 of the base 148 and a first row 220A of chambers 210 that is most proximate to the first edge side 206. The orphan slots 234 are aligned with the columns 218 of chambers 210. Each of the orphan slots 234 is generally linear and oriented parallel to the first edge side 206. The orphan slots 234 are configured to receive orphan shields 240 (shown in
The contact assembly 153 is inserted into a corresponding chamber 210 by moving the contact assembly 153 relative to the housing 138 in a loading direction 280. The signal pod 154 and the ground shield 146 of each contact assembly 153 are inserted as a single package into a same chamber 210. In the illustrated embodiment, the contact assembly 153 is loaded into the base 148 from the rear side 114 towards the front side 112, but the contact assemblies 153 may be configured to be loaded in the reverse direction in other embodiments.
In an embodiment, the ground shield 146 of the contact assembly 153 may engage the chamber walls 212 at multiple contact locations along a height of the base 148 between the front side 112 and the rear side 114 to electrically connect the ground shield 146 to the base 148 at the multiple contact locations. The exterior sides 192 of the ground shield 146 and/or the protrusions 195 (shown in
The contact assembly 153 may be secured in the chamber 210 to fix the position of the contact assembly 153 relative to the housing 138. The contact assembly 153 may be held in the chamber 210 via an interference fit. For example, the dielectric body 156 may engage the interior sides 190 of the ground shield 146 and force the ground shield 146 outward against the chamber walls 212 to increase the friction between the ground shield 146 and the chamber walls 212, as well as retain a conductive electrical connection between the ground shield 146 and the chamber walls 212. The dielectric body 156 may be at least partially compressed within the chamber 210. The crush ribs 174 (shown in
In an embodiment, the base 148 further includes grooves 230 defined in the chamber walls 212 along the rear side 114 of the base 148. The grooves 230 are open to the chambers 210 and extend laterally therefrom into or through the chamber walls 212. The grooves 230 receive the tabs 187 of the ground shields 146 therein. The engagement between the tabs 187 and the grooves 230 may also provide a hard stop interface as the contact assembly 153 is being loaded into the chamber 210 that prevents the contact assembly 153 from being loaded beyond a desired loaded position.
The ground shields 146 are positioned between the signal pods 154 of adjacent contact assemblies 153 to provide electrical shielding between adjacent pairs 158 of signal contacts 144. In the illustrated embodiment, the ground shield 146 of each contact assembly 153 has a C-shaped cross-section and surrounds the associated signal pod 154 on three sides thereof. The ground shield 146 of an adjacent contact assembly 153 provides shielding along the open, fourth side of the signal pod 154. Therefore, the pairs 158 of signal contacts 144 are shielded from adjacent pairs 158 in the same column 218 and adjacent pairs 158 in the same row 220. For example, the ground shield 146 of a first contact assembly 153A provides shielding for the signal contacts 144 of the first contact assembly 153A on three sides of the signal pod 154 of the first contact assembly 153A. The ground shield 146 of a second contact assembly 153B adjacent to the first contact assembly 153A in the same column 218 provides shielding for the signal contacts 144 of the first contact assembly 153A along an open, fourth side 260 of the signal pod 154 of the first contact assembly 153A. The ground shield 146 of the second contact assembly 153B provides shielding for the signal contacts 144 of the second contact assembly 153B on three sides thereof. As shown in
The ground shields 302 may be mechanically secured and/or chemically bonded to the corresponding dielectric bodies 156 of the contact assemblies 153 to retain each ground shield 302 in a fixed position relative to the corresponding dielectric body 156. For example, as shown in
In the illustrated embodiment, the housing 138 includes positioning tabs 318 extending into each chamber 210 and engaging the dielectric body 156 of the contact assembly 153 therein. The positioning tabs 318 in the chambers 210 bias the contact assemblies 153 into engagement with the electrically conductive chamber walls 212 of the housing 138 to electrically common the ground shields 302 of the contact assemblies 153.
Although not shown in the portion of the connector 104 illustrated in
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the 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.
