RELATED APPLICATIONS

[0001 j This application claims priority to United States Provisional Patent Application having Serial No. 62/518,984 filed on June 13, 2017, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] This disclosure relates to the field of input/output (IO) connectors, more specifically to IO connectors suitable for use in high data rate applications.

DESCRIPTION OF RELATED ART

[0003] Input/output (IO) connectors are designed to support high data rates and a number of improvements have been developed to help provide data rates that reach 25 Gbps and even higher. In order to support consumer needs and desires, however, many companies are looking at ways to support higher data rates. As a result, development work into supporting 50 Gbps using NRZ encoding and 100 Gbps using PAM 4 encoding are underway. These increases will pose significant problems for existing manufacturing techniques, however, as conventional circuit boards cannot readily support 25 GHz signals. Thus, new architectures and methods will be required.

[0004] Another method to support increased data rates has been to try to increase the number of ports. One way to increase the number of ports is to shrink the size of the connector. For example, it is common for many standard connectors to be designed to work on a 0.8 mm or 0.75 mm pitch and recently a connector standard that support 0.5 mm has been approved (the OCULIN connector). While shrinking the connector size works well for clean sheet designs and is effect at supporting very high density at the front of rack, smaller connectors are more challenging to use for optical connector designs as the very small size makes it challenging to dissipate sufficient thermal energy. They also tend to use smaller sized conductors, which makes it difficult to support more than 2 or 3 meter length cables. In addition, for people that wish to have some level of backward compatibility, the new smaller connector size poses potential issues. As a result, certain individuals would appreciate further improvements in connector technology.

SUMMARY

[0005] A connector is disclosed that includes a set of wafers formed of terminals supported by an insulative frame. The set of wafers can be positioned in a cage without a housing. Card slot members are aligned with contacts of the terminals. In an embodiment a connector can include a wafer that supports two rows of terminals on both sides of a card slot. At least some of the terminals include a contact at one end which is over molded with an insulative material. These contacts are over molded except for the end of the terminal which is left exposed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:

[0007] Fig. 1 illustrates a perspective view of an embodiment of connector system.

[0008] Fig. 2 illustrates a perspective sectional view of the embodiment depicted in Fig. 1, taken along line 1-1 .

[0009] Fig. 3 illustrates another perspective view of the embodiment depicted in Fig. 1.

[0010] Fig. 4 illustrates a simplified perspective view of the embodiment depicted in Fig. 3.

[0011] Fig. 5 illustrates a perspective view of an embodiment of a plug module prior to insertion into a receptacle.

[0012] Fig. 6 illustrates a perspective view of an embodiment of a receptacle.

[0013] Fig. 7A illustrates a perspective sectional view of the embodiment depicted in Fig. 6, taken along line 7-7.

[0014] Fig. 7B illustrates an enlarged simplified perspective view of the embodiment depicted in Fig. 7A. 15] Fig. 7C illustrates a enlarged perspective view of an embodiment depicted in Fig. 7A.

[0016] Fig. 8 illustrates a perspective view of the embodiment depicted in Fig. 6 with the cage partially removed.

L7] Fig. 9 illustrates a simplified perspective vi ew of the embodiment depicted in Fig. 6 with the top wall and front portion of the cage removed.

1.8] Fig. 10 illustrates a perspective cross-sectional view of the embodiment depicted in Fig. 7 with a modified top wall.

[0019] Fig. 1 1 A illustrates a perspective view of an embodiment of a connector.

[0020] Fig. 1 IB illustrates an enlarged perspective view of the embodiment depicted in Fig. 1 A.

] Fig. 12 illustrates another perspecti ve view of the embodiment depicted in Fi g. 1 1 A.

12] Fig. 13 illustrates a partially exploded perspective view of the embodiment depicted in Fig. 1 1A.

13] Fig. 14 illustrates an enlarged perspective view of the embodiment depicted in Fig. 13.

[0024] Fig. 15 illustrates a perspective view of the embodiment depicted in Fig. 13 with the card slot plug removed.

[0025] Fig. 16 i llustrates a perspective view of an embodiment of a retaining bar securing a wafer set.

[0026] Fig. 17 illustrates an exploded partial perspective view of an embodiment of a connector.

[0027] Fig. 18 illustrates a partially exploded perspective view of an embodiment of a signal wafer pair surrounded by ground wafers. [0028] Fig. 19 illustrates a simplified perspective view of the embodiment depicted in Fig. 18 with an insulative frame removed for illustrative purposes.

[0029] Fig. 20 illustrates a perspective view of an embodiment of a signal wafer pair. [0030] Fig. 21 illustrates a perspective view of the embodiment with the insulative frame removed.

[0031] Fig. 22 illustrates a perspective view of an embodiment of terminals that provide the contact rows in the bottom port.

[0032] Fig. 23 illustrates another perspective view of the embodiment depicted in Fig. 22.

[0033] Fig. 24 illustrates an elevated side view of the embodiment depicted in Fig, 22.

[0034] Fig. 25 A illustrates a plan view of the embodiment depicted in Fig. 21 ,

[0035] Fig. 25B illustrates an enlarged plan view of the embodiment depicted in Fig. 25 A.

[0036] Fig. 26 illustrates a schematic depiction of an embodiment of a connector with an insert.

[0037] Fig. 27 illustrates a simplified perspective view of an embodiment of a connector.

[0038] Fig. 28 illustrates a simplified perspective view of an embodiment of a set of wafers.

[0039] Fig. 29 illustrates a simplified perspective view of an embodiment of a single wafer.

[0040] Fig. 30 illustrates a simplified perspective view of an embodiment of a single wafer showing hidden features.

[0041] Fig. 31 illustrates a simplifi ed perspective view of an embodiment of a single wafer.

[0042] Fig. 32 illustrates a simplified perspective view of an embodiment of a single wafer with an insulative frame removed for illustrative purposes.

[0043] Fig. 33 illustrates an enlarged perspective view of an embodiment of terminals as part of a wafer with hidden features shown. DETAILED DESCRIPTION

[0044] The detailed description that follows describes exemplary embodiments and is not intended to be limited to the expressly disclosed combination(s). Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity.

[0045] As can be appreciated from Figs, 1-5, a receptacle 100 is mounted on a circuit board and provides a right-angled construction that is configured to receive plug module 20. The depicted receptacle 100 design is beneficial to use with plug modules that include cooling slots 115. While the use of cooling slots 115 in a module is not required the cooling slots 115 can provide additional cooling and make it easier, when used with other features disclosed herein, to cool a module that uses 8 or more watts of power.

[0046] The receptacle 100 includes a cage 120 and can support light pipes 105 if desired. The cage includes a top wall 122, a first side wall 123, a second side wall 124, a rear wall 124 and a front edge 126. The receptacle 100 defines a top port 121a and a bottom port 121 b. The first and second side wails 123, 124 can include vent apertures 135.

[0047] As can be appreciated, the depicted designs are intended to facilitate cooling of an inserted plug module 20. Thus, the design has been tailored to improve air flow in a number of ways that will be discussed herein. In certain embodiments the receptacle 100 can include an internal riding heat sink 134 that is in communication with a front grill 130 and a rear aperture set 132. The top wall 122 can include a cooling aperture 122a and an external riding heat sink 133 can be positioned therein. Riding heat sinks are typically designed so that the extend into the port and engage an inserted plug module, helping to provide a conductive path to direct heat away from the plug module. It should be noted that in certain circumstances it may not be desirable to have the additional cooling (for example, in applications where there is no intention to use active modules) and in such situations many of the optional thermal features can be omitted. Thus, the depicted internal riding heat sink and the various venting features can be omitted if not desired.

[0048] One common design of existing receptacles is the use of a housing positioned inside of a cage, the housing helping to define a connector. The cage helps support the mating plug module, can help support the connector and can also provide EMI protection. The connector positioned in the cage supports terminals that include tails and contacts that allow the mating plug module to he electrically connected to a circuit board (or to cables if a Bipass design is desired). The receptacle, which is typically press-fit onto a circuit board to ease assembly, thus must have the terminals of the connector aligned with terminals on the cage. As can be appreciated, the cage can be formed of metal and is expected to have a fairly repeatable arrangement of tails that have the desired dimensional control with respect to each other. The tails of the connector can also be carefully manufactured so that they are aligned with each other. It is somewhat more difficult, however, to align the tails of the connector with the tails of the cage as there are multiple points of dimensional stack-up. This dimensional issue is made more difficult by the fact that in a typical press fit design the housing supports wafers that support the terminals. Thus, the terminals are dimensional controlled with respect to each other within a wafer but have dimensional stack-up with respect to both the housing and other wafers while the housing has dimensional stack-up with the cage. Prior designs attempted to have a datum that acts as a stop to carefully control insertion of the housing into the cage to control the tolerances between the datum point and the tails of both the cage and the connector.

[0049] While such control is possible, it turns out to be more challenging and difficult, particularly as the tails are reduced in si ze. Applicants have determined that instead of having a stop that limits and controls the position of the housing with respect to the cage it is more desirable to have a system where the cage 120 and connector 129 are mated together in a manner that allows for infinite adjustment over a small range so that mating of the cage 120 and the connector 129 can be done in a controlled manner and dimensional control can be assured. As depicted, the cage 120 includes bottom walls 140, 141 that each have a tongue 142 that is inserted into the respective card slot plug 150, 160. More specifically, the tongues 142 from the cage 120 are inserted into tongue slots 153, .163 in mating portions 152, 162, respectively, of card slot plugs 150, 160. As can be appreciated, the card slot plugs 1 50, 160 engage a wafer set 220 and would provide some additional dimensional stack up therebetween. In an embodiment, the insertion can be done based on alignment between the wafer set 220 and the cage 120, thus eliminating some of the dimensional stack up that would otherwise exist. In an embodiment the tongues 142 have an interference fit with the tongue slots 153, 163 so that the cage and connector 129 are appropriately joined and stay at the appropriate location relative to each other. Such a manufacturing process allows a position of the cage 120 and the wafer set 220 to be better controlled with respect to each other and improves the yield of receptacles 100 while ensuring the receptacle 00 can properly be mounted on a circuit board.

[0050] As can be appreciated from the Figures, the depicted connector 129 omits a housing. Applicants have surprisingly discovered that the use of a housing is unnecessary to support a wafer set 220 so long as the wafers are securely fastened together, preferably on at least two sides. In a depicted embodiment retaining bars 171 are positioned on opposing sides and one of the sides has two retaining bars 171. The retaining bars 171 are connected to wafers 221 via wafer nubs 229 that can be heat staked onto the retaining bars 171. The depicted connector 129 illustrates an embodiment where a triangular arrangement is provided with two retaining bars 171 positioned on one side and one retaining bar 171 positioned on a second side of the wafer set. While it is desirable to have at least two retaining bars 171 (each positioned on a different- side of the connector) a triangular arrangement of retaining bars 171 has been determined to be beneficial as it provides improved control and support for wafers 221 that make up the wafer set 220. It has been determined that removing the housing provides certain unexpected benefits. One issue is that no housing is perfectly square and straight, thus the tolerance in the housing adds to the tolerance in the wafers and thus increases the tolerance of the location of the tails. By removing the housing Applicants can better control the position of the tails of the wafer set with respect to the cage. The removal of the housing also allows for the size of the receptacle to be decreased, thus allowing for increased density.

[0051] Each wafer 221 includes an insulative frame 221a. The depicted insulative frames 221a includes top projections 224 and supports terminal sets 252, 262, 272 (as is expected in embodiments where there is a three wafer system that includes a ground wafer and two signal wafers). It should be noted that the configuration of the depicted terminals, while beneficial for the depicted receptacle, is not intended to be limiting as the features of providing a connector without a housing has broad applicability. Thus, the design elements that provide for the removal of the housing could be used with a wide range of wafer configurations.

[0052] The terminal set 252 includes terminals 253 that each include a contact 253a, a tail 253b and a body 253c that extends therebetween. Similarly, the terminal set 262 includes terminals 263 that include a contact 263a, a tail 263b and a body 263c that extends therebetween. As the depicted tails 253b, 263b are intended to press-fit into a circuit board it is helpful to provide a receptacle where force can be readily applied to the tails to press them into vias on a circuit board. As depicted, the insulative frame 121a includes top projections that extend to a top wall 122 of the cage 120. As a result of the depicted design, a force exerted on the cage 120 is transferred through the insulative frame 121a to the tails 253b, 263b and thus a reliable press-fit operation is possible.

[0053] The depicted top projections 124 have a number of cutouts 124a so that the wafer engages the top wall in several places but also leaves gaps. The cutouts 124a can be arranged in a pattern that allows air to flow along the top wall 122 of the cage in a desirable manner. As can be appreciated, the number and size of the cutouts 124a, as well as the location, can vary as appropriate to provide the desired air flow.

[0054] It should be noted that the cutouts 124a, while providing a tortuous path for air to flow through, do not provide a straight path for the air to flow between the wafers and the top wall and thus may increase the pressure drop of air flow through the receptacle. While the depicted path could be considered a zig-zag or undulating path, other paths could also be provided, depending on the configuration of the top wall. In an alternative embodiment the projection 124 can be shortened and an insert 129a (shown in schematic representation in Fig. 26) can positioned between the wafer set 220 and the top wall 122. The insert 129a can transfer force from the top wall 122 to the wafers 221 while providing a more optimized air flow path between the top wall 122 and the wafer set 220 (thus reducing air resistance). In another alternative embodiment the insert 129a can be removeabie and just used to mount the connector on the circuit board 10 before being removed. In such a design the back wall 125 of the cage 120 can be attached after the cage 120 (or at least most of it) and connector 129 are both pressed into the circuit board and the opening can provide reduced air resistance. Thus, a number of variations are possible, depending on the need for air flow and the desire to manage costs.

[0055] The depicted design provides wafers 221 that have a front contact row 245 and a rear contact row 246 that are spaced apart in a plug module insertion direction and the contact rows are configured to engage two rows of pads on a mating connector. While not required, the benefit of such a design is a substantial increase in density. If such density is not desired then the wafers can be made to support a lesser number of terminals. It should be noted that depicted wafers are arranged in pattern that provides a ground, signal, signal pattern that can be repeated. Other patterns are also possible if desired. If desired, the ground wafers could include terminals that are commoned together and in an embodiment the ground wafers could have contacts that engage the top wall to provide electrical grounding to the cage.

[0056] Because the connector 129 does not need a housing (although it is possible to use a housing if desired in certain embodiments), the depicted connector 129 supports card slots plugs with the wafer set 220. As depicted, the card slot plugs 150, 160 each have shoulders that are similar to the shoulders 156a, 156b that latch onto retaining features on at least some of the wafers in the wafer set 220 to provide desirable location and stability control . In an embodiment just the ground wafers can include retention features. As depicted, the shoulders 156a, 156b can have grooves 154 that engage projections 226 but other retention configurations would also be suitable. The card slot plugs 150, 160 are positioned in ports 121a, 121b defined by the cage 120 and provide card slots 151 that have contacts positioned on both sides of the card slots 151. The card slots 151 preferably include terminal grooves 155 for the front contact row 245 so that the most vulnerable contacts are protected during the initial mating with a mating plug connector. As the front portion of the card slot plugs 50, 60 helps align and control the mating paddle card, the rear contact row 246 can beneficially omit the terminal slots. If desired a card slot plug 160 can include a peg 166 that is intended to be inserted into a circuit board but such a feature is optional and is not expected to be as helpful for a design that includes two vertically arranged ports in a 2XN configuration.

[0057] In an embodiment the retaining bar 171 can be configured to engage the cage 120. The retaining bar 171 can be made wider than the wafer set 220 so that the retaining bar 171 slides along the side walls of the cage220. If such a construction (which helps ensure proper alignment of the cage 120 to the wafer set 220) is desired then the retaining bar 171 can include vent apertures 172 to allow air to flow more readily through the receptacle.

[0058] It has been determined that for a full double row design it is desirable that the contacts ail be blanked and formed (it has been determined that this provides mechanical and signal integrity benefits). Thus, the depicted embodiment features two rows of stamped and formed contacts on both sides 151a, 151 b of the card slot ! 51.

[0059] To support the front contact row 245, the wafers 221 include an arm 228 that extends past the rear contact row 246. The arm 228 helps ensure the impedance is more consistently managed through the body of the wafer. To provide for suitable flexibility the arm 228 can include a notch 228a that allows that arm 228 to flex slightly.

[0060] As noted above, each of the terminals includes the contact, tail and body extending therebetween. The depicted configuration includes a ground wafer 271 and a signal wafer set 250 that includes a first signal wafer 251 and a second signal wafer 261. The signal wafer set 250 thus provides for the top port a first different pair 254a, a second differential pair 254b, a third differential pair 254c and a fourth differential pair 254d, The signal wafer set 250 also provides for the bottom port a fifth differential pair 255a, a sixth differential pair 255b, a seventh differential pair 255c and an eighth differential pair 255d, From the depicted terminal configuration it can be appreciated that for both the top and bottom ports the terminals that form the two back differential pairs have tails that are positioned between tails of the two differential pairs that form the front contacts. For example, differential tail sets 257b and 257c are associated with contact pairs 258b and 258c, respectively and the contact pairs 258b, 258c are in the rear contact row. Differential tail sets 257a and 257d are on both sides of the differential tail sets 257b, 257c and are associated with contact pairs 258a, 258d that are in the front contact row. It has been determined that this configuration is beneficial as it allows for the three rows of terminals to have similar lengths while having one significantly longer terminal . Thus, the depicted embodiment helps provide more consistent terminal lengths.

[0061] As can be appreciated, a top row of contacts opposes a bottom row of contacts. In an embodiment the contacts of the terminals that form that the top row of contact can have a form 256b that is folded in a first direction and the terminals that form the bottom row of contacts can have a form 256a that is also folded in the first direction. For example, when looking straight at the contacts in a plug module insertion direction all the sets of contacts can have forms that are folded to one side (e.g., they can all be folded to the left or to the right). While such a construction is beneficial, it turns out that for certain applications it is desirable to have the top row of contacts offset from the bottom row of contacts. To provide this functionality the contact can taper down from a beam portion 302a, 302b to a pad touching portion 301 a, 301b, where the pad touching portion 301a, 301b is less than half the width of the beam portion 302a, 302b. If desired, the pad touching portion of the top row can be on opposite sides of the beam portion as the pad touching portions on the bottom row so as to provide an offset alignment. If such an alignment is not needed then the contacts can be configured symmetrically or in some other desired configuration.

[0062] The pitch can vary depending on the intended interface. As depicted the terminals are on a x pitch, which could be 0,8 mm and the top and bottom terminals can have a y offset, which can be 0.4 mm. If the connector provides a double row of contacts on the top and bottom and the front contacts are intended to be compatible with existing designs then it will be beneficial to have the pitch of the contacts match existing designs. If a clean sheet design is preferred then the pitch can be varied as desired, keeping in mind that signal integrity performance can be more challenging as the pitch decreases below 0,8 mm and that a pitch below 0.65 typically requires additional features such as biased paddle cards and/or contact interface (such as is used in the OCULINK connector).

[0063] Figs. 27-34 depict alternative embodiments of certain aspects of the connector embodiments that were described with reference to Figs. 1-26 above. The embodiments now described with respect to Figs. 27-34 may be combined with certain connector embodiments already described, in whole or in part, depending on the particular aspect being implemented. Thus, some connector embodiment aspects may remain unchanged, some aspects replaced with staictures now described, and some aspects modified to incorporate the structures now described.

[0064] Similar to wafer designs already described, wafers 521 have a front contact row 5 5 and a rear contact row 546 that are spaced apart in a plug module insertion direction and the contact rows are configured to engage two rows of pads on a mating connector. While not required, the benefit of such a design is a substantial increase in density. If such density is not desired then the wafers can be made to support a lesser number of terminals. It should be noted that depicted wafers are arranged in a manner that provides a ground-signal-signal pattern that can be repeated. Other patterns are also possible. If desired, the ground wafers could include terminals that are commoned together and in an embodiment the ground wafers could have contacts that engage the top wall to provide electrical grounding to the cage.

[0065] In contrast to wafer designs already described, rear contact row 546 as depicted is setback (in a rearward direction) from a front edge 547 of the insulative frames of wafers 521. Setting the rear contact row back from this front edge may reduce crosstalk. Also, as best depicted in Fig, 32, several terminals having alternative structures are shown with the wafer insulative frame removed. The terminals each include a contact, a tail, and a body that extends therebetween. The bodies each include a beam portion and the contacts each include a contact portion and an end. For example, terminal 553 includes end 553a, contact portion 553b, beam portion 553c, and tail 553d. In some embodiments, beam portion 553c comprises a flat blanked beam.

[0066] In these embodiments, the flat blanked beam has several advantages, in particular, manufacturabiiity. In previously-described embodiments, the contact portion of the wafer included multiple rows/columns of terminals. The geometry of these terminals includes bends and forms that are normal to the blanking direction of the lead frame. This involves added progressions in the stamping process with increased complexity for the associated tooling. In flat-blanked beam embodiments, the blanking and forming can be performed with minimal progressions and in some instances a single operation. This lends itself to high volume manufacturing, such as reel-to reel processes.

[0067] The contact portion 553b of the terminal is over molded with an insulative material so that only the end 553a of the terminal is exposed for making electrical contact. As best- depicted in Fig. 33, there is substantially no stub portion of the terminal extending beyond the protruding end 553a. By reducing or eliminating the stub portion of the terminals, stub effects are reduced and impedance matching can be improved. The insulative material (such as a plastic material, for example) may be insert molded around the contact portion of the terminal during a reel-to-reel manufacturing process, for example. Also, over molding the contact portions of terminals in adjacent wafers can provide increased side-to-side stability for the terminal contacts and better ensure that electrical contact is made with the intended pad. Moreover, the molded contact portions may be specifically sized to provide accurate terminal pitch control.

[0068] In some embodiments, the contacts of different terminals are over molded with an insulative material to a different extent. See, for example, the differences in the over molded contacts that are depicted in Fig. 27. In this example, the contacts of the terminals in the signal wafers are over molded with an insulative material to a greater extent than the contacts of the terminals in the ground wafers. [0069] In general, terminal contacts have a lead-in to prevent stubbing of a module board when being inserted. One type of lead-in takes the form of a conductive extension of the terminal contact point, a stub. Such stubs can degrade signal integrity (SI), however. Another type of lead-in takes the form of an over molded terminal contact portion. In this example, an insulative material is used as a lead-in for the module board, thereby avoiding the use of a conductive stub for this purpose.

[0070] The disclosure provided herein describes features in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.