CN113835166A - Optical pluggable module for communication system - Google Patents

Abstract

A communication system (500) includes a host circuit board (502) and an interposer assembly (508) coupled to the host circuit board, the interposer assembly having an interposer substrate (600) including host circuit board contacts (606) at a lower surface (604) and module contacts (608) at an upper surface (602). The communication system includes an optical pluggable module (506) having a mating interface (538) along a bottom portion of the optical pluggable module that faces the interposer assembly. The optical pluggable module includes a module substrate (540) and an optical engine (550) coupled to the module substrate, with a fiber optic cable (542) extending from the optical engine to a cable end (534). The module substrate has module substrate contacts (564) at a lower surface (562) of the module substrate that are electrically connected to corresponding module contacts of the interposer package at an upper surface of the interposer substrate.

Description

Optical pluggable module for communication system

Technical Field

The subject matter herein relates generally to communication systems having pluggable modules.

Background

At least some known communication systems include a receptacle assembly, such as an input/output (I/O) connector assembly, configured to receive a pluggable module and establish a communication connection between the pluggable module and a host circuit board. As one example, known receptacle assemblies include a cage member mounted to a circuit board and configured to receive a pluggable transceiver in an elongated cavity of the cage member. The receptacle assembly includes an electrical communication connector that includes contacts that are terminated to a host circuit board, such as by a soldered or press-fit connection. The contacts of the electrical communication connector have mating ends in the card slots for mating with the pluggable module. The pluggable module has a circuit card therein that is received in the card slot for electrical connection with the electrical communication connector. The cable of the pluggable module is terminated to the circuit card, such as by soldering the conductors of the cable to the circuit card.

Conventional communication systems are not without their drawbacks. For example, a communication system has multiple interfaces between conductors of a cable and a host circuit board. For example, interfaces are defined between the conductors and the circuit card of the pluggable module, between the circuit card and contacts of an electrical communication connector of the receptacle assembly, and between the contacts of the electrical communication connector and the host circuit board. Electrical communication connectors mounted to a receptacle assembly of a host circuit board add cost to the system and cause problems in reflection, noise and attenuation and electrical performance, particularly at high data rates. Similarly, circuit cards in pluggable modules add cost to the system and cause problems in reflection, noise and attenuation and electrical performance, especially at high data rates.

Accordingly, there is a need for a communication system having a robust and efficient signal path between a pluggable module and a host circuit board.

Disclosure of Invention

In accordance with the present invention, a communication system is provided that includes a host circuit board having a mounting area extending between a front and a rear and having contact pads within the mounting area. The interposer assembly is coupled to a host circuit board at a mounting area. The interposer assembly has an interposer substrate including an upper surface and a lower surface. The interposer assembly has host circuit board contacts on a lower surface that are electrically connected to corresponding contact pads of a host circuit board and module contacts on an upper surface. The communication system includes an optically pluggable module that extends longitudinally between a mating end and a cable end. The optical pluggable module includes a mating interface along a bottom portion of the optical pluggable module that faces the interposer assembly. An optical pluggable module includes a module substrate and an optical engine coupled to the module substrate. The optical pluggable module has a fiber optic cable extending from the optical engine to a cable end. The module substrate has module substrate contacts at a lower surface of the module substrate that are electrically connected to corresponding module contacts of the interposer assembly at an upper surface of the interposer substrate.

Drawings

Fig. 1 is a front perspective view of a communication system according to an embodiment.

Figure 2 is a perspective view of a portion of a communication system showing a pluggable module 106 and an interposer assembly, according to an example embodiment.

Figure 3 is a perspective view of a portion of a communication system showing a portion of a pluggable module relative to a host circuit board.

Figure 4 is a side view of a portion of a pluggable module according to an exemplary embodiment, showing a cable assembly and a corresponding interposer assembly.

Fig. 5 is a bottom perspective view of a portion of a pluggable module according to an exemplary embodiment, illustrating a portion of a cable assembly.

Fig. 6 is a side perspective view of a portion of a pluggable module showing a cable assembly coupled to an interposer assembly.

Fig. 7 is a top perspective view of a portion of a pluggable module showing a portion of a cable assembly.

Figure 8 is a front perspective view of a communication system showing a pluggable module in a partially loaded position, under an embodiment.

Figure 9 is a front perspective view of a communication system showing pluggable modules in a fully loaded position, according to an exemplary embodiment.

Figure 10 is a side view of a portion of a communication system showing a portion of a pluggable module with respect to a host circuit board in accordance with an exemplary embodiment.

Figure 11 is a top perspective view of a portion of a pluggable module in accordance with an exemplary embodiment.

Fig. 12 is a cross-sectional view of a communication system according to an example embodiment.

Fig. 13 is an enlarged cross-sectional view of a portion of the communication system shown in fig. 12 according to an example embodiment.

Fig. 14 is a side perspective view of a portion of a communication system showing an optical pluggable module in an unmated state with respect to an interposer assembly in accordance with an exemplary embodiment.

Figure 15 is a side partial cut-away view of a portion of a communication system showing an optical pluggable module, according to an example embodiment.

Fig. 16 is a side perspective view of a portion of a communication system showing a portion of an optical pluggable module in accordance with an example embodiment.

Detailed Description

Fig. 1 is a front perspective view of a communication system 100 according to an embodiment. The communication system 100 includes a host circuit board 102, a receptacle assembly 104 mounted to the host circuit board 102, a pluggable module 106 configured to be received in the receptacle assembly 104, and an interposer assembly 108 (shown in fig. 2) configured to be received in the receptacle assembly 104. The interposer assembly 108 electrically connects the pluggable module 106 and the host circuit board 102. The interposer assembly 108 is positioned between the pluggable module 106 and the host circuit board 102. For example, the interposer assembly 108 and pluggable module are vertically stacked on the host circuit board 102.

The communication system 100 may be part of or used with a remote communication system or device. For example, communication system 100 may be part of or include a switch, router, server, hub, network interface card, or storage system. Host circuit board 102 may be a daughter card or a motherboard and includes conductive traces (not shown) extending therethrough. In the illustrated embodiment, the pluggable module 106 is an input/output (I/O) module configured to be inserted into and removed from the receptacle assembly 104. The pluggable module 106 is configured to transmit data signals in the form of electrical signals. In various embodiments, the interposer assembly 108 is secured to the host circuit board 102, e.g., soldered to the host circuit board 102, and the pluggable module 106 is connected to the interposer assembly 108 at a separable mating interface, whereby the pluggable module 106 can be easily and repeatedly mated and unmated with the interposer assembly 108. In other various embodiments, the interposer assembly 108 may form a portion of the pluggable module 106, with the pluggable module 106 being loaded into the receptacle assembly 104 and removed from the receptacle assembly 104 to repeatedly mate and unmate with the host circuit board 102.

In the illustrated embodiment, the receptacle assembly 104 is shown as a single port receptacle assembly configured to receive a single pluggable module 106; however, in other embodiments, the receptacle assembly 104 may be a multi-port receptacle assembly configured to receive the pluggable module 106 in multiple ports. For example, the plurality of ports of the receptacle assembly 104 may be grouped side-by-side along a top surface of the host circuit board 102.

The receptacle assembly 104 includes a cage member 110 mounted to the host circuit board 102. The cage member 110 may be disposed at a frame or panel (not shown) of a rack of a system or device, for example, through an opening in the panel. Thus, the cage member 110 is internal to the device and corresponding panel, and the pluggable module(s) 106 are loaded into the cage member 110 from outside or exterior of the device and corresponding panel. Optionally, the panel may include a plurality of openings, each configured to receive a corresponding pluggable module 106.

Cage member 110 includes a front end 112 and an opposite rear end 114. The front end 112 is disposed at the panel and extends through an opening in the panel. Relative or spatial terms such as "front," "back," "top," "bottom," and the like are used solely to distinguish between the referenced elements and do not necessarily require a particular position or orientation in the communication system 100 or in the surrounding environment of the communication system 100. For example, the front end 112 may be located in or facing the rear of a larger telecommunications system. In many applications, the front end 112 is visible to a user when the user inserts the pluggable module 106 into the receptacle assembly 104. When the pluggable module 106 is inserted into the receptacle assembly 104, the pluggable module 106 is accessible and visible to the user.

The cage member 110 is configured to suppress or block interference, such as electromagnetic interference (EMI), and to guide the pluggable module(s) 106 during mating operations. To this end, the cage member 110 includes multiple pieces that are assembled together to enclose the pluggable module 106 and the interposer assembly 108. For example, the parts may be snapped together and/or welded together. When cage member 110 is mounted to host circuit board 102, cage member 110 is electrically coupled to host circuit board 102, and in particular is electrically coupled to a ground plane (not shown) within host circuit board 102 to electrically ground cage member 110. As such, the receptacle assembly 104 may reduce EMI that may adversely affect the electrical performance of the communication system 100. The pluggable module 106 and/or the interposer assembly 108 may be co-potential or grounded with the cage member 110, such as for EMI suppression and/or shielding. For example, the pluggable module 106 and/or the interposer assembly 108 may directly engage a portion of the cage member 110, such as an EMI gasket at an opening of the cage member 110.

In an exemplary embodiment, cage member 110 includes a plurality of shell panels or walls 116, which may be formed from one or more pieces. The various walls 116 provide shielding for vulnerable areas of other components, such as by covering or shielding openings in the walls of the other components. Cage member 110 extends between a front end 112 and a rear end 114. The wall 116 is formed of a conductive material, such as a metal sheet and/or a polymer with conductive particles. In the illustrated embodiment, the parts are stamped and formed from sheet metal. In some embodiments, the cage member 110 is configured to facilitate airflow through the cage member 110 to transfer heat (or thermal energy) away from the receptacle assembly 104 and the pluggable module(s) 106 and/or the interposer assembly 108. Air may flow from the interior of cage member 110 (e.g., behind the panels) to the external environment (e.g., in front of the panels) or from the exterior of cage member 110 into the interior of cage member 110. A fan or other air moving device may be used to increase the airflow through the cage member 110 and over the pluggable module(s) 106.

The cage member 110 defines a module cavity 120 extending between the front end 112 and the rear end 114. The front end 112 of the cage member 110 has a port 122 that opens into the module cavity 120. The module cavity 120 receives the pluggable module 106 through the port 122. The module cavity 120 extends lengthwise in a direction parallel to the loading axis 128 of the pluggable module 106. With the multi-port receptacle assembly 104, a plurality of module cavities 120 or ports are defined for receiving the plurality of pluggable modules 106. In such an embodiment, the module cavities may be horizontally grouped. A divider plate may be provided between the module chambers 120 to provide shielding between the module chambers 120.

In the exemplary embodiment, cage member 110 has a top 124 and a bottom 126. Cage member 110 includes one of walls 116 at top 124. The base 126 is mounted to the host circuit board 102. In an exemplary embodiment, the bottom 126 is open to allow the pluggable module 106 and the interposer assembly 108 to mate with the host circuit board 102 at the bottom 126.

In an exemplary embodiment, the receptacle assembly 104 may include an EMI gasket (not shown) at the front end 112 of the cage member 110. The EMI gasket may interface with a panel, such as within an opening in the panel that receives the receptacle assembly 104. The EMI gasket may extend into the module cavity 120 to engage the pluggable module 106.

Figure 2 is a perspective view of a portion of the communication system 100 showing the pluggable module 106 and the interposer assembly 108, according to an example embodiment. The cage member 110 (fig. 1) has been removed to show the pluggable module 106 and the interposer assembly 108 stacked on the host circuit board 102. The interposer assembly 108 is configured to mate directly with the host circuit board 102 along the length of the host circuit board 102, such as directly beneath the pluggable module 106. The pluggable module 106 is configured to directly mate with the interposer assembly 108.

The pluggable module 106 has a pluggable body 130, which may be defined by one or more housings. The pluggable module 106 has one or more cable assemblies 140 that are retained by the pluggable body 130. Optionally, the pluggable body 130 may provide heat transfer for the cable assembly 140. The pluggable body 130 includes a rear or mating end 132 and an opposite front or cable end 134. The mating end 132 is configured to be inserted into the module cavity 120 (shown in fig. 1). Each cable assembly 140 has one or more cables 142 extending from cable end 134, which cables 142 may be routed to other components within the system.

The pluggable body 130 has a top 135 and a bottom 136. The bottom portion 136 faces the interposer assembly 108 and the host circuit board 102. The base 136 defines an interface 138 configured to mate to the interposer assembly 108. The top 135 and bottom 136 extend longitudinally between the mating end 132 and the cable end 134. In an exemplary embodiment, the pluggable module 106 is loaded into the cage member 110 in the first mating direction along a loading axis 128, which loading axis 128 may be substantially parallel to the host circuit board 102. The pluggable module 106 may mate with the interposer assembly 108 in a second mating direction, which may be substantially perpendicular to the first mating direction. For example, the pluggable body 130 may be pressed downward toward the interposer assembly 108 and the host circuit board 102 to mate the pluggable module 106 directly with the interposer assembly 108. Optionally, the cage member 110 may include features that engage the pluggable body 130 and urge the pluggable body 130 in a downward mating direction toward the host circuit board 102. For example, the cage member 110 may include guide rails or tracks that define the path of movement of the pluggable body 130 during loading and mating. In the illustrated embodiment, the pluggable body 130 includes guide features 143 extending from the sides, the guide features 143 configured to be received in guide tracks of the cage member 110 to guide movement of the pluggable body 130 during loading and mating.

In an exemplary embodiment, the pluggable module 106 includes a latch 144 for latchably securing the pluggable module 106 to the cage member 110 and/or the host circuit board 102. The latch 144 may include a latching feature (not shown) configured to engage the cage member 110 and/or the host circuit board 102. The latching feature may be released to release the pluggable module 106 to allow the pluggable module 106 to be removed from the cage member 110. In the exemplary embodiment, latch 144 includes an actuator 148, such as a clip and pull tab, for actuating latch 144. The actuator 148 may be used to press or force the pluggable module 106 into the cage member 110 and/or may be used to pull the pluggable module 106 out of the cage member 110.

Fig. 3 is a perspective view of a portion of the communication system 100 illustrating a portion of the pluggable module 106 with respect to the host circuit board 102. The cage member 110 (shown in fig. 1) and the pluggable body 130 (shown in fig. 2) are removed to illustrate the cable assembly 140 according to an exemplary embodiment. Any number of cable assemblies 140 may be provided, including a single cable assembly 140, depending on the particular application and the number of signal lines being transmitted by the pluggable module 106.

Each cable assembly 140 includes a cable 142. Cable assembly 140 includes a cable connector 150 at an end of cable 142. In an exemplary embodiment, the cable connector 150 includes a ground shield 152 that surrounds portions of the cable 142 and other components of the cable connector 150, such as components configured to mate directly with the interposer package 108, as described in further detail below. The ground shield 152 provides electrical shielding for the cable 142 and other components of the cable connector 150.

The cable 142 and the cable connector 150 are configured to be received within the pluggable body 130. The cable connectors 150 are loaded into and removed from the cage member 110 with the pluggable body 130, and the cable connectors 150 are configured to mate to the interposer assembly 108 during loading of the pluggable body 130 into the cage member 110. Optionally, the pluggable module 106 may include multiple cable connectors 150 within the pluggable body 130 that each individually mate with the interposer assembly 108 or a corresponding plurality of interposer assemblies 108, such as when multiple interposer assemblies 108 are used rather than a single interposer assembly 108. For example, a plurality of cable connectors 150 may be longitudinally spaced between the mating end 132 and the cable end 134 of the pluggable body 130.

The interposer assembly 108 is configured to mate directly with the host circuit board 102 at the mounting area 154 of the host circuit board 102. For example, the interposer assembly 108 may be soldered or otherwise electrically connected to signal contact pads (e.g., traces or circuits) and ground contact pads (e.g., traces, circuits or ground layers) within the mounting area 154. The receptacle assembly 104 (shown in fig. 1) is configured to be mounted to the host circuit board 102 at a mounting area 154. For example, cage member 110 may terminate at mounting region 154 to host circuit board 102, such as to a ground via in host circuit board 102.

Figure 4 is a side view of a portion of the pluggable module 106 illustrating one of the cable assemblies 140 and the corresponding interposer assembly 108 according to an example embodiment. Figure 5 is a bottom perspective view of a portion of the pluggable module 106 illustrating a portion of the cable assembly 140 according to an exemplary embodiment.

The cable connector 150 includes a contact assembly 160 configured to be terminated to a cable 142 of the cable assembly 140. The contact assembly 160 is configured to mate directly with the interposer assembly 108 (fig. 5). The contact assembly 160 includes a plurality of signal contacts 162 and one or more ground contacts 164. In the illustrated embodiment, the ground contacts 164 are defined by ground plates 165. The ground shield 152 is terminated to a ground plate 165. For example, the ground shield 152 may include press-fit pins that press into the ground plate 165 to form an electrical connection between the ground shield 152 and the ground plate 165. The ground plate 165 has a plurality of mating interfaces for mating with the interposer package 108. The contact assembly 160 includes a contact holder 166 that holds the signal contacts 162 and/or the ground contacts 164. In an exemplary embodiment, the contact holder 166 may be overmolded onto the signal contact 162. The ground plate 165 includes openings 168 that receive the ends of the signal contacts 162. The ends of the signal contacts 162 may be coplanar with the ground plate 165.

In an exemplary embodiment, the contact assembly 160 is an overmolded lead frame. The signal contacts 162 are formed from stamped and formed leadframes that are overmolded by an overmolded body that forms the contact holder 166. For example, the signal contacts 162 may be stamped from a common piece of metal and held together by a carrier strip prior to being overmolded by the overmolded body. Once overmolded, the carrier strip may be removed, thereby electrically isolating the signal contacts 162 from one another.

In the exemplary embodiment, the signal contacts 162 are arranged in pairs configured to carry differential signals. The ground contacts 164 may separate pairs of the signal contacts 162 to provide electrical shielding between the pairs of signal contacts 162. For example, the ground plate 165 may be located between the pair of signal contacts 162 and the ground shield 152 may be located between the pair of signal contacts 162. Optionally, the ground plate 165 and the ground shield 152 may form a shield recess around each pair of signal contacts 162 to shield the pairs of signal contacts 162 from each other. In alternative embodiments, other arrangements are possible.

Referring to fig. 4, in an exemplary embodiment, the interposer assembly 108 includes an interposer substrate 200 including an upper surface 202 and a lower surface 204. In various embodiments, the interposer substrate 200 may be an interposer circuit board. In other various embodiments, the interposer substrate 200 may be a structure other than a circuit board, such as an overmolded lead frame. The interposer assembly 108 includes host circuit board contacts 206 on the lower surface 204 that are configured to electrically connect to corresponding contact pads on the host circuit board 102. The interposer assembly 108 includes cable assembly contacts 208 on the upper surface 202 that are configured to be electrically connected to corresponding signal contacts 162 and ground contacts 164 of the contact assembly 160.

In the illustrated embodiment, the host circuit board contacts 206 are defined by solder balls. For example, the host circuit board contacts 206 are ball grid arrays at the lower surface 204 of the interposer substrate 200. The solder balls are configured to be reflow soldered to the host circuit board 102. In alternative embodiments, other types of contacts may be used for the host circuit board contacts 206, such as spring contacts, land grid arrays, or other types of contacts. Once the host circuit board contacts 206 are soldered to the host circuit board 102, the interposer assembly 108 is non-removably coupled to the host circuit board 102. The pluggable module 106 may be mated and unmated with the interposer assembly 108 without removing the interposer assembly 108 from the host circuit board 102.

In the illustrated embodiment, the cable assembly contacts 208 are spring contacts that are configured to mate with the pluggable module 106. Each cable assembly contact 208 includes a terminating end 210 and a mating end 212. Each cable assembly contact 208 includes a deflectable spring beam 214 between the termination end 210 and the mating end 212. The termination end 210 is configured to be terminated to the interposer substrate 200. For example, the termination end 210 may include a solder pad configured to be soldered to the upper surface 202 of the interposer substrate 200, or the termination end 210 may include a press-fit pin configured to be press-fit into a plated through-hole of the interposer substrate 200. The mating end 212 defines a separable mating interface 216 with the contact assembly 160. The contact assembly 160 may be reliably and repeatably mated and unmated with the separable mating interface 216 without adversely damaging the cable assembly contacts 208 or the contacts 162, 164 of the contact assembly 160. The deflectable spring beams 214 are configured to elastically deform when mated with the contact assembly 160. The deflectable spring beams 214 form a reliable electrical connection between the cable assembly contact 208 and the contacts 162, 164 of the contact assembly 160.

Fig. 6 is a side perspective view of a portion of the pluggable module 106, showing one of the cable assemblies 140 coupled to the interposer assembly 108. In an exemplary embodiment, the cable assembly contacts 208 may be arranged in a plurality of rows for engaging the signal contacts 162 and the ground contacts 164 (both shown in fig. 4). The cable assembly contacts 208 electrically connected to the ground contacts 164 provide electrical shielding for the cable assembly contacts 208 electrically connected to the signal contacts 162. Alternatively, the signal contacts of the cable assembly contacts 208 may be arranged in pairs and surrounded by respective ground contacts of the cable assembly contacts 208, e.g., on all four sides.

In the illustrated embodiment, the ground plate 165 defines the ground contacts 164. The ground shield 152 is electrically connected to the ground plate 165 by ground pins 220 (e.g., press-fit pins). The ground shields 152 and ground plates 165 define shield recesses 222 for the signal contacts 162. The contact holder 166 is received in the shield recess 222.

Fig. 7 is a top perspective view of a portion of the pluggable module 106, showing a portion of one of the cable assemblies 140. In an exemplary embodiment, the contact assembly 160 includes a ground plate 165, the ground plate 165 defining a lower ground plate, and an upper ground plate 167 that is elevationally spaced from the lower ground plate 165. The upper ground plate 167 may form a portion of the ground shield 152. The ground shield 152 includes a sidewall 169 extending between the upper ground plate 167 and the lower ground plate 165. The ground plates 165, 167 and the side wall 169 define the shield recess 222.

In an exemplary embodiment, each cable 142 may be a twinaxial cable having a pair of signal conductors 224, as well as insulator(s) 230 surrounding the signal conductors 224 and a cable shield 232 providing electrical shielding for the pair of signal conductors 224. Optionally, each cable 142 may include a drain wire (not shown). Each cable 142 includes a cable jacket 236 (shown in fig. 6) that protects cable 142. Other types of cables 142 may be used in alternative embodiments. The cables 142 are received in corresponding shield recesses 222. In an exemplary embodiment, the lower and/or upper ground plates 165, 167 and/or the sidewalls 169 can be electrically connected to the exposed cable shield 232 in the shield recess 222 to electrically connect the cable 142 to the cable connector 150.

Each of the signal contacts 162 includes a terminating end 180, a mating end 182 opposite the terminating end 180, and an intermediate portion 184 between the terminating end 180 and the mating end 182. In the exemplary embodiment, intermediate portion 184 is retained by contact retainer 166 (fig. 6). For example, the middle portion 184 may be overmolded. Optionally, the intermediate portion 184 may be necked or narrower than the other portions, for example, to allow for more dielectric material between the signal contacts 162 and the sidewall 169 and/or for signal integrity through the contact holder 166.

The terminating end 180 is terminated to a corresponding signal conductor 224 of the cable 142. For example, the end of the cable 142 may be stripped to expose a length of the signal conductors 224. The signal conductors 224 may be soldered to the termination end 180. In alternative embodiments, the signal conductors 224 may be terminated to the termination end 180 by other means, such as by crimping, insulation displacement connections, or other types of termination. The contact retainers 166 may be used to space the signal conductors 224 at a predetermined pitch that matches the pitch of the signal conductors 224 for termination therewith.

The mating end 182 is configured to mate directly to the cable assembly contact 208 (shown in fig. 6). In an exemplary embodiment, the signal contacts 162 include pads 186 at the mating end 182 that define separable mating interfaces 188 at the distal end for repeated mating and unmating with the cable assembly contacts 208. Other types of mating ends 182 may be provided in alternative embodiments, such as mating ends having deflectable spring beams. The pads 186 may mate with the cable assembly contacts 208 in a horizontal loading direction and/or a vertical mating direction. For example, the pluggable module 106 is loaded in the loading direction and may move downward to contact the cable assembly contacts 208 at the final stage of loading to create downward pressure on the cable assembly contacts 208 when mated with the cable assembly contacts 208. The downward pressure compresses the deflectable spring beams of the cable assembly contact 208 such that the deflectable spring beams spring bias against the mating end 182 of the signal contact 162.

Figure 8 is a front perspective view of the communication system 100 illustrating the pluggable module 106 in a partially loaded position, under an embodiment. Figure 9 is a front perspective view of the communication system 100 showing the pluggable module 106 in a fully loaded position, according to an example embodiment. The cage member 110 of the receptacle assembly 104 includes guide features 250 along the wall 116. In the illustrated embodiment, the guide features 250 are guide tracks 252 that are configured to receive the guide features 143 of the pluggable module 106.

In an exemplary embodiment, the guide track 252 includes a seating portion 254 for seating the pluggable module 106 to the interposer assembly 108. For example, at the distal end of the guide rail 252, the guide rail 252 is stepped downward to define a seating portion 254. When the pluggable module 106 is loaded into the receptacle assembly 104, the guide features 143 ride in the guide tracks 252 to the seating portions 254. In the seating portion 254, as the pluggable module 106 continues to be loaded into the receptacle assembly 104, the pluggable module 106 is pushed downward toward the host circuit board 102. In the illustrated embodiment, the seating portion 254 is angled such that the pluggable module 106 has horizontal and vertical movement within the seating portion 254. When the pluggable module 106 is pushed downward toward the host circuit board 102, the pluggable module 106 is electrically connected to the interposer assembly 108. The signal contacts 162 and the ground contacts 164 are mated to the cable assembly contacts 208 of the interposer assembly 108. The cable assembly contacts 208 are compressed when mated with the pluggable module 106.

In an exemplary embodiment, the actuator 148 of the latch 144 may be used to push the pluggable module 106 in the loading direction. For example, the operator may press the actuator 148 to push the pluggable module 106 in the loading direction. During removal, an operator may pull in the actuator 148 to remove the pluggable module 106 from the receptacle assembly 104. During removal, the guide tracks 252 may guide the removal of the pluggable module 106. During removal, the guide feature 143 rides in the guide track 252. Other types of latching and guiding features may be used in alternative embodiments.

Figure 10 is a side view of a portion of the communication system 100 showing a portion of the pluggable module 106 with respect to the host circuit board 102, according to an example embodiment. Figure 11 is a top perspective view of a portion of a pluggable module 106 in accordance with an exemplary embodiment. The embodiment shown in figures 10-11 utilizes an interposer assembly 108 as part of the pluggable module 106. The interposer assembly 108 defines a connector assembly 350 that is terminated to the end of the cable 142 of the cable assembly 140. The interposer assembly 108 is configured to be loaded into and unloaded from the receptacle assembly 104 (shown in figure 1) using the pluggable module 106.

The interposer assembly 108 includes an interposer substrate 300 including an upper surface 302 and a lower surface 304. In various embodiments, interposer substrate 300 may be an interposer circuit board. In other various embodiments, interposer substrate 300 may be a structure other than a circuit board, such as an overmolded lead frame. The interposer assembly 108 includes host circuit board contacts 306 on the lower surface 304 that are configured to electrically connect to corresponding contact pads on the host circuit board 102. The interposer assembly 108 includes cable assembly contacts 308 on the upper surface 302 that are configured to electrically connect to the cables 142.

In the illustrated embodiment, the cable assembly contacts 308 are defined by circuitry 310 of the interposer substrate 300. For example, the circuitry 310 may include traces, vias, pads, and the like. In the exemplary embodiment, signal conductors 224 of cable 142 are terminated directly to circuitry 310. For example, the signal conductors 224 may be soldered to the circuit 310. In the exemplary embodiment, ground bus 312 is electrically coupled to cable shield 232 of cable 142, and ground contacts 314 of ground bus 312 are directly terminated to circuitry 310. For example, the ground contact 314 may be soldered to the circuit 310. In alternative embodiments, other types of contacts may be used for the host circuit board contacts 306, such as spring contacts, insulation displacement contacts, crimp contacts, and the like. Once the cable assembly contacts 308 are terminated to the cable 142, the interposer assembly 108 is non-removably coupled to the cable assembly 140. Alternatively, the ends of cable 142 may be overmolded to interposer substrate 300 to form strain relief between cable 142 and interposer substrate 300. The interposer assembly 108 and the pluggable module 106 may be mated and unmated to the host circuit board 102 without removing the interposer assembly 108 from the cable assembly 140 of the pluggable module 106.

In the illustrated embodiment, the host circuit board contacts 306 are spring contacts configured to mate with the host circuit board 102. Each host circuit board contact 306 includes a terminating end 320 and a mating end 322. Each host circuit board contact 306 includes a deflectable spring beam 324 between the end contact end 320 and the mating end 322. The termination terminals 320 are configured to be terminated to the interposer substrate 300. For example, the termination end 320 may include a solder pad configured to be soldered to the lower surface 304 of the interposer substrate 300, or the termination end 320 may include a press-fit pin configured to be press-fit into a plated through-hole of the interposer substrate 300. The mating end 322 defines a mating interface 326 that is separable from the host circuit board 102. The interposer assembly 108 can be reliably and repeatably mated and unmated from the host circuit board 102 at the separable mating interface 326 without adversely damaging the host circuit board contacts 306 or the host circuit board 102. The deflectable spring beams 324 are configured to elastically deform when mated with the host circuit board 102. The deflectable spring beams 324 form a reliable electrical connection between the host circuit board contacts 306 and the host circuit board 102.

Fig. 12 is a cross-sectional view of a communication system 500 according to an example embodiment. Fig. 13 is an enlarged cross-sectional view of a portion of communication system 100 according to an example embodiment. Communication system 500 is similar to communication system 100 and includes similar components and features. The communication system 500 includes an optical pluggable module 506 instead of the electrical pluggable module 106 of the communication system 100.

The communication system 500 includes a host circuit board 502, a socket assembly 504 mounted to the host circuit board 502, and an interposer assembly 508 received in the socket assembly 504. The interposer assembly 508 is coupled to the host circuit board 502. The optical pluggable module 506 is configured to be received in the receptacle assembly 504 to couple to the interposer assembly 508. The interposer assembly 508 electrically connects the optical pluggable module 506 and the host circuit board 502. The interposer assembly 508 is positioned between the optically pluggable module 506 and the host circuit board 502. For example, the interposer assembly 508 and pluggable module are vertically stacked on the host circuit board 502.

The communication system 500 may be part of or used with a remote communication system or device. For example, communication system 500 may be part of or include a switch, router, server, hub, network interface card, or storage system. Host circuit board 502 may be a daughter card or a motherboard and include conductive traces (not shown) extending therethrough. The optical pluggable module 506 is configured to transmit data signals in the form of optical signals. In various embodiments, the interposer assembly 508 is secured to the host circuit board 502, e.g., soldered to the host circuit board 502, and the optical pluggable module 506 is connected to the interposer assembly 508 at a separable mating interface, whereby the optical pluggable module 506 can be easily and repeatedly mated and unmated with the interposer assembly 508. In other various embodiments, the interposer assembly 508 may form part of an optical pluggable module 506 that is loaded into and removed from the receptacle assembly 504 to repeatedly mate and unmate with the host circuit board 502.

In the illustrated embodiment, the receptacle assembly 504 is shown as a single port receptacle assembly configured to receive a single optical pluggable module 506; however, in other embodiments, the receptacle assembly 504 may be a multi-port receptacle assembly configured to receive a plurality of optical pluggable modules 506 in a plurality of ports. For example, the plurality of ports of the receptacle assembly 504 may be grouped side-by-side along the top surface of the host circuit board 502.

Receptacle assembly 504 includes a cage member 510 mounted to host circuit board 502. Cage member 510 may be similar to cage member 110. Cage member 510 includes a front end 512 and an opposite rear end 514. In an exemplary embodiment, cage member 510 includes a plurality of shell panels or walls 516, which may be formed of one or more pieces. The walls 516 are formed of a conductive material, such as sheet metal and/or polymer with conductive particles, to provide electrical shielding. Cage member 510 defines a module cavity 520 extending between front end 512 and rear end 514. The front end 512 of the cage member 510 has a port 522 that opens into the module cavity 520. The module cavity 520 receives the optical pluggable module 506 through the port 522. The module cavity 520 extends lengthwise in a direction parallel to a loading axis 528 of the optical pluggable module 506. In the exemplary embodiment, cage member 510 has a top portion 524 and a bottom portion 526. Bottom 526 is mounted to host circuit board 502. In an exemplary embodiment, the bottom 526 is open to allow the optical pluggable module 506 and the interposer assembly 508 to mate with the host circuit board 502 at the bottom 526. The interposer assembly 508 is configured to mate directly with the host circuit board 502 along the length of the host circuit board 502, e.g., directly under the optical pluggable module 506. The optical pluggable module 506 is configured to directly mate with the interposer assembly 508.

The optical pluggable module 506 has a pluggable body 530, which may be defined by one or more housings. The optical pluggable module 506 includes a module substrate 540 and one or more optical engines 550 coupled to the module substrate 540. The module substrate 540 is retained by the pluggable body 530. The pluggable body 530 includes a rear or mating end 532 and an opposite front or cable end 534. The mating end 532 is configured to be inserted into the module cavity 520. Fiber optic cable 542 extends from optical engine 550 to cable end 534 and may be routed to another component within the system.

The pluggable body 530 has a top 535 and a bottom 536. The bottom 536 faces the interposer package 508 and the host circuit board 502. The bottom portion 536 defines an interface 538 configured to mate to the interposer package 508. The top 535 and bottom 536 extend longitudinally between the mating end 532 and the cable end 534. In an exemplary embodiment, the optical pluggable module 506 is loaded into the cage member 510 in a first mating direction along a loading axis 528, which may be substantially parallel to the host circuit board 502. The optical pluggable module 506 may mate with the interposer assembly 508 in a second mating direction, which may be substantially perpendicular to the loading direction. For example, the pluggable body 530 may be pressed downward toward the interposer assembly 508 and the host circuit board 502 to mate the optical pluggable module 506 directly with the interposer assembly 508. Optionally, the cage member 510 may include features that engage the pluggable body 530 and push the pluggable body 530 in a downward mating direction toward the host circuit board 502. For example, the cage member 510 may include guide rails or tracks that define the path of movement of the pluggable body 530 during loading and mating. In the illustrated embodiment, the pluggable body 530 includes guide features extending from the sides that are configured to be received in guide tracks of the cage member 510 to guide movement of the pluggable body 530 during loading and mating.

In an exemplary embodiment, the optical pluggable module 506 includes latches 544 for latchably securing the optical pluggable module 506 to the cage member 510 and/or the host circuit board 502. Latch 544 may include a latching feature (not shown) configured to engage cage member 510 and/or host circuit board 502. The latching feature may be released to release the optically pluggable module 506 to allow the optically pluggable module 506 to be removed from the cage member 510. In an exemplary embodiment, the latch 544 includes an actuator, such as a clip and pull tab, for actuating the latch 544. The actuator may be used to press or force the optical pluggable module 506 into the cage member 510 and/or may be used to optically pull the pluggable module 506 out of the cage member 510.

The module substrate 540 includes an upper surface 560 and a lower surface 562. The module substrate 540 has module substrate contacts 564 on the lower surface 562. The module substrate contacts 564 are configured to be electrically connected to the interposer assembly 508. The module substrate contacts 564 may be contact pads, circuit traces, vias, or other types of conductors. Optical engine 550 is mounted to upper surface 560. Optical engine 550 can be electrically connected to module substrate 540, such as soldered to contacts of module substrate 540 or press-fit into through-holes of module substrate 540. The optical engine 550 includes an electrical-to-optical converter to convert between electrical and optical signals. The fiber optic cable 542 is optically coupled to the electrical-to-optical converter.

The interposer assembly 508 is configured to mate directly with the host circuit board 502 at a mounting area 554 of the host circuit board 502. For example, the interposer assembly 508 may be soldered or otherwise electrically connected to signal contact pads (e.g., traces or circuits) and ground contact pads (e.g., traces, circuits, or ground layers) within the mounting region 554. The receptacle assembly 504 (shown in fig. 12) is configured to be mounted to the host circuit board 502 at a mounting area 554. For example, cage member 510 may be terminated to host circuit board 502 at mounting region 554, such as to a ground via in host circuit board 502.

In an exemplary embodiment, the interposer assembly 508 includes an interposer substrate 600 that includes an upper surface 602 and a lower surface 604. In various embodiments, interposer substrate 600 may be an interposer circuit board. In other various embodiments, interposer substrate 600 may be a structure other than a circuit board, such as an overmolded lead frame. The interposer assembly 508 includes host circuit board contacts 606 on the lower surface 604 that are configured to electrically connect to corresponding contact pads on the host circuit board 502. In the illustrated embodiment, the host circuit board contacts 606 are defined by solder balls. The optical pluggable module 506 may be mated and unmated with the interposer assembly 508 without removing the interposer assembly 508 from the host circuit board 502.

Interposer assembly 508 includes module contacts 608 on upper surface 602 that are configured to electrically connect to corresponding module substrate contacts 564 of module substrate 540. In the illustrated embodiment, the module contacts 608 are spring contacts configured to mate to the optical pluggable module 506. Each module contact 608 includes a deflectable spring beam 614 between a terminating end 610 and a mating end 612. The termination end 610 is configured to be terminated to the interposer substrate 600. The mating end 612 defines a separable mating interface with the contact assembly 560. The contact assemblies 560 can reliably and repeatably mate and unmate with the separable mating interfaces 616 without adversely damaging the module contacts 608.

Fig. 14 is a side perspective view of a portion of the communication system 500, showing the optical pluggable module 506 in an unmated state with respect to the interposer assembly 508. Fig. 15 is a side, partial cross-sectional view of a portion of the communication system 500, showing the optical pluggable module 506 in an unmated state with respect to the interposer assembly 508. Fig. 16 is a side perspective view of a portion of the communication system 500, showing a portion of the optical pluggable module 506 in an unmated state with respect to the interposer assembly 508.

During mating, the optical pluggable module 506 is loaded into the cage member 510 in a first mating direction along a loading axis 528 (which is removed to illustrate the optical pluggable module 506 relative to the interposer assembly 508 for clarity), the loading axis 528 being generally parallel with the host circuit board 502. The optical pluggable module 506 may mate with the interposer assembly 508 in a second mating direction, which may be substantially perpendicular to the loading direction. For example, the pluggable body 530 may be pressed downward toward the interposer assembly 508 and the host circuit board 502 to mate the optical pluggable module 506 directly with the interposer assembly 508.

In an exemplary embodiment, the module contacts 608 may be arranged in a plurality of rows to engage the module substrate 540. The module contacts 608 are electrically connected to the module substrate 540 when mated. The module substrate 540 may be pressed down against the module contacts 608 to compress the module contacts 608. An optical engine 550 is provided on the module substrate 540, and a fiber optic cable 542 extends from the optical engine 550. In an exemplary embodiment, the optical engine 550 is longitudinally offset along the length of the module substrate 540. For example, the optical engine 550 may be longitudinally offset between the mating end 532 and the cable end 534. In an exemplary embodiment, the optical engine 550 is laterally offset across the width of the module substrate 540.

Claims (11)

1. A communication system (500), comprising:

a host circuit board (502) having a mounting region (554) extending between a front and a rear, the host circuit board having contact pads within the mounting region;

an interposer assembly (508) coupled to the host circuit board at the mounting region, the interposer assembly having an interposer substrate (600) including an upper surface (602) and a lower surface (604), the interposer assembly having host circuit board contacts (606) at the lower surface that are electrically connected to corresponding contact pads of the host circuit board, the interposer assembly having module contacts (608) at the upper surface; and

an optical pluggable module (506) extending longitudinally between a mating end (532) and a cable end (534), the optical pluggable module including a mating interface (538) facing the interposer assembly along a bottom (536) of the optical pluggable module, the optical pluggable module including a module substrate (540) and an optical engine (550) coupled to the module substrate, the optical pluggable module having fiber optic cables (542) extending from the optical engine to the cable end, the module substrate having module substrate contacts (564) at a lower surface (562) of the module substrate that electrically connect to corresponding module contacts of the interposer assembly at an upper surface of the interposer substrate.

2. The communication system (500) of claim 1, wherein the fiber optic cables (542) are bundled into a multi-fiber cable bundle at the cable end (534).

3. The communication system (500) of claim 1 wherein the optical engine (550) comprises an electrical-to-optical converter coupled to the module substrate (540) and electrically connected to corresponding module substrate contacts (564).

4. The communication system (500) of claim 1, wherein the optical engine (550) comprises a transmitting optical engine and a receiving optical engine.

5. The communication system (500) of claim 1, wherein the optical pluggable module (506) mates with the interposer assembly (508) in a mating direction parallel to a bottom (536) of the optical pluggable module.

6. The communication system (500) of claim 1, wherein the interposer assembly (508) is coupled to the host circuit board (502) and the optical pluggable module (506) is mateable to and unmatable from the interposer assembly.

7. The communication system (500) of claim 1 wherein the module contacts (608) include deflectable spring beams (614) having separable mating interfaces (616).

8. The communication system (500) of claim 1, wherein the optical engine (550) comprises a first optical engine and a second optical engine longitudinally offset relative to the first optical engine such that the second optical engine is disposed closer to the cable end (534) than the first optical engine.

9. The communication system (500) of claim 8 wherein the second optical engine (550) is laterally offset on the module substrate (540) relative to the first optical engine.

10. The communication system (500) of claim 1, wherein the optical pluggable module (506) includes a guide feature configured to guide mating of the optical pluggable module with a cage member (510) of a receptacle assembly (504).

11. The communication system (500) of claim 1, wherein the optically-pluggable module (506) is loaded in place on the mounting area of the host circuit board (502) in a horizontal loading direction to a loading position, the interposer assembly (508) being vertically stacked between the module substrate (540) and the host circuit board.

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