The present invention relates, generally, to a printed circuit board (PCB)-based, backplane connector assemblies, and, more specifically, to a PCB-based backplane connector system having a blind-mate optical interface.
Printed circuit board (PCB)-based backplane connectors are well known. For example, the MULTIGIG RT interconnect family from TE Connectivity (TE) are employed in a variety of computer, communications, medical, industrial control, and military applications. These connector systems use a printed circuit board (PCB) card or “wafer” instead of a traditional pin and socket contact system, thereby eliminating the open pin field on the plug-in module portion of the backplane connectors and reducing the end user's exposure to field failure in card cage systems. A typical PCB backplane daughter card connector assembly comprises a housing defining a plurality of slots, in which each slot is configured to receive an individual PCB wafer.
Applicant recognized that the PCB wafer may be improved by adding functionality to the wafer to convert between electrical signals and optical signals. To that end, Applicant, discloses a high-density optical daughter-card connector assembly, described, for example, in U.S. Pat. No. 10,852,489. This optical daughter-card connector assembly fulfilled many needs, especially with respect to its configurable free-end optical fibers. Yet, Applicant recognizes an additional need for an optical daughter-card connector assembly that is blind mateable. The present invention fulfills these needs, among others.
The following presents a simplified summary of the invention to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
Accordingly, in one embodiment, the present invention relates to a daughter-card connector assembly comprising: (a) a housing defining a first plane configured for mounting parallel to a backplane, and a second plane for mounting parallel to a daughter card, and a plurality of parallel slots perpendicular to the first plane; and (b) one or more opto-electric cards, each of the one or more opto-electric cards disposed in one of the plurality of slots, and comprising at least, (i) a printed circuit board (PCB) defining at least a first edge and a second edge, wherein, when the opto-electric card is mounted in the slot, the first edge is parallel to the first plane and the second edge is parallel to the second plane; (ii) a blind-mate optical connector along the first edge; (iii) an electrical interface along the second edge; (iv) at least one optical component mounted on the PCB for converting between electrical and optical signals, the PCB being electrically connected to at least a portion of the electrical interface; and (v) one or more waveguides connecting the optical component with the optical connector
In another embodiment, the present invention relates to an opto-electric card for mounting in a slot of a housing of a daughter-card connector assembly, the housing defining a first plane configured for mounting parallel to a backplane, and a second plane for mounting parallel to a daughter card, and a plurality of parallel slots perpendicular to the first plane, the card comprising: (a) a printed circuit board (PCB) configured to be received within the slot, and defining at least a first edge and a second edge, wherein, when the opto-electric card is mounted in the slot, the first edge is parallel to the first plane and the second edge is parallel to the second plane; (b) a blind-mate optical connector along the first edge; (c) an electrical interface along the second edge; (d) at least one optical component mounted on the PCB for converting between electrical and optical signals, the PCB being electrically connected to at least a portion of the electrical interface; and (e) one or more waveguides connecting the optical component with the optical connector.
Referring to
Each of these elements/features are described in detail below in connection with selected, alternative embodiments.
In one embodiment, the daughter-card connector assembly comprises discrete/modular opto-electric cards 104. In one embodiment, each discrete opto-electric card is releasably engageable with the housing 101. In one embodiment, the housing 101 comprises a plurality of slots 102 and each opto-electric card 104 is slidably engageable with one of the slots. Generally, each opto-electric card comprises one or more optical components for transmitting/receiving electrical/optical signals, although it should be understood that an opto-electric card may be a dedicated optical receiver, or a dedicated optical transmitter. In this respect, the modular configuration of the opto-electric card allows for a given daughter-card connector assembly to be configured in different ways. For example, a daughter-card connector assembly may comprise a portion of opto-electric cards configured for transceiving, and another portion of opto-electric cards dedicated to receiving and/or transmitting, depending on the application.
Not only does the modularity of the opto-electric card provide flexibility in configuring the daughter-card connector assembly with transceiving/transmitting/receiving opto-electric cards, but also provides scalability. That is, rather than purchasing and installing a daughter-card connector assembly with its full complement of channels, in one embodiment, the daughter-card connector assembly of the present invention may be scaled up to meet the demands of the application. For example, initially, a backplane connector housing with relatively few opto-electric cards may be installed, and, later, additional opto-electric cards may the added to the housing as the demand for additional channels grows. Thus, in one embodiment, the daughter-card connector assembly of the present invention provides for a pay-as-you-grow solution.
Another benefit of the modular configuration of the opto-electric card is the ability to replace defective opto-electric cards or to upgrade opto-electric cards periodically without having to replace the entire daughter-card connector assembly. In other words, unlike a conventional transceiver in which the entire transceiver must be replaced if one or more channels become inoperable, just the inoperable or out-of-date opto-electric card needs to be replaced in one embodiment of the backplane connector assembly. Thus, the modular configuration of the opto-electric cards eliminates single-point failures of the entire daughter-card connector assembly. Moreover, the discrete opto-electric card solution of the present invention enables a configurable ratio of channel protection. More specifically, the scalable configuration of the present invention enables the user to configure precisely the level of channel protection desired—e.g., from 1:1 redundancy to 1:N redundancy—rather than having to provide an entire, singular redundant multichannel transceiver (e.g., 12 channel device) at a greater initial and replacement cost.
One important feature of the daughter-card connector assembly is the blind mate optical connector 107 on the first edge 105 of the opto-electric card 103. Such a connector facilitates the blind mating of the connector to the backplane. As shown, the optical connector is an MT style optical connector having alignment pins/alignment pin holes 150 on its ends and fiber end faces 151 presented in the center. In this particular embodiment, the distance between the alignment pinholes is relatively large compared to the relatively few fibers presented in the center of the ferrule. Such a configuration is generally preferred (although not necessary) because the longer distance between the fiber end faces and the alignment pinholes tends to improve the alignment fiber end faces with the fiber end faces of the mating con106nector on the backplane. Although an MT style connector is shown in the embodiment of
As shown in
In one embodiment, the first edge of the card 104 also comprises an electrical interface 130 for connection to a mating connector on the backplane. In one embodiment, the electrical interface on the first edge is a blind mate electrical connector.
In one embodiment, the electrical interface on the 2nd edge of the card is similar to that disclosed in U.S. Pat. No. 9,196,985, incorporated herein by reference. Likewise, in one embodiment, the second plane of the housing has a daughter card interface similar to the daughter card interface defined in the '985 patent. Specifically, in one embodiment, the daughter card interface comprises eye-of-the-needle connectors 120 along the second plane. (Such connectors are well known and will not be described herein in detail.)
In one embodiment, the optical component 110 comprises an interposer 110a and a chip 110b. The interposer 110a comprises an innovative interposer that minimizes hysteresis and simplifies optical alignments. One embodiment of the interposer of the present invention is disclosed, for example, in U.S. patent application Ser. No. 16/450,189, hereby incorporated by reference in its entirety. In one embodiment, the interposer 110a is perpendicular to the opto-electric card as shown in
In one embodiment, the interposer integrates both the optical device and the chip. As used herein, the optical device may be any known or later-developed component that can be optically coupled to an optical conduit as described below. The optical device may be for example: (a) an opto-electric device (OED), which is an electrical device that sources, detects and/or controls light (e.g., lasers, such as vertical cavity surface emitting laser (VCSEL), double channel, planar buried heterostructure (DC-PBH), buried crescent (BC), distributed feedback (DFB), distributed Bragg reflector (DBR); light-emitting diodes (LEDs), such as surface emitting LED (SLED), edge emitting LED (ELED), super luminescent diode (SLD); photodiodes, such as P Intrinsic N (PIN) and avalanche photodiode (APD); photonics processor, such as, a CMOS photonic processor, for receiving optical signals, processing the signals and transmitting responsive signals, electro-optical memory, electro-optical random-access memory (EO-RAM) or electro-optical dynamic random-access memory (EO-DRAM), and electro-optical logic chips for managing optical memory (EO-logic chips)); or (b) a hybrid device which does not convert optical energy to another form but which changes state in response to a control signal (e.g., switches, modulators, attenuators, and tunable filters). It should also be understood that the optical device may be a single discrete device, or it may be assembled or integrated as an array of devices. It should also be understood that the optical device may be a single mode or multimode device. In one embodiment, the optical device is a surface emitting light source. In one embodiment, the surface emitting light source is a VCSEL. In one embodiment, the optical component is photo sensitive. In one embodiment, the photo sensitive optical component is a photodiode.
In one embodiment, the optical component works in conjunction with one or more electronic chips 110b. A chip as used herein refers to any electronic/semiconductor chip needed to facilitate the function of the optical component. For example, if the optical component is a transmitter, then the chip may be a driver, or, if the optical component is a receiver, then the chip may be a transimpedance amplifier (TIA). The required chip for a given optical component is well known in the art and will not be described here in detail.
Although the chip is disposed on the opto-electric card as shown in
Now referring to
Retainer block 301 functions to secure the connector 300 to the backplane 303 and hold the ferrules in proper register with respect to the opto-electric cards of the daughter-card connector assembly. This can be achieved in different ways. For example, in the embodiment of
Although the retainer block shown in
In one embodiment, the retainer block (or at least a portion thereof) comprises metal or other heat conducting material to draw heat away from the opto-electric cards of the daughter-card connector assembly. For example, in one embodiment, the opto-electric cards comprise one or more thermal conductive pads 130, as shown in
The ferrule spring retainer functions to retain the springs that urge the ferrules forward. Applicant found that the relatively small pitch between the opto-electric cards makes the conventional approach of using a spring retainer for each ferrule difficult. Consequently, in one embodiment of the present invention, a single ferrule retainer retains springs for multiple ferrules. For example, referring to
In the embodiment shown in
Referring to
As shown in
Referring to
In one embodiment, the wafer is thermally coupled to backplane connector and/or the daughter card to communicate heat away from the wafer. For example, in one embodiment, the card edge connector of the PCB wafer comprises one or more thermal pads to conduct heat from the opto-electric card through the connector and into the backplane connector. In another embodiment, thermal connectors among the connectors 120 are configured to conduct heat from the opto-electric card to the daughter card. Alternatively, the heat sink 1001 may also be thermally coupled to the thermal pads or thermal conductors mentioned above. In one embodiment, the robustness of the heatsink 1001 may be used to dissipate heat from the daughter cards. In such an embodiment, the thermal conductors would be configured to conduct heat away from the daughter cards and into the heatsink 1001 for dissipation into the environment. Still other embodiments for dissipating heat will be obvious to one of skill in the art in light of this disclosure.
These and other advantages may be realized in accordance with the specific embodiments described as well as other variations. It is to be understood that the above description is intended to be illustrative, and not restrictive. 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.
This application is based on U.S. Provisional Application No. 63/452,385, filed Mar. 15, 2023, and U.S. Provisional Application No. 63/538,205 filed, Sep. 13, 2023, both of which are incorporated by reference in their entirety.
Number | Date | Country | |
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63452385 | Mar 2023 | US | |
63538205 | Sep 2023 | US |