CPO connector and receptacle with one-piece molded receptacle and hinged cover

Abstract

An assembly for co-packaged optics includes a receptacle and a cover configured to receive and retain an FAU assembly / connector on a board. The cover has a lower cover portion with arms that engage the receptacle through coupling portions with apertures, and a main cover portion with upper and lower cover surfaces and prongs extending from cover sides. Each prong includes two prong portions separated by a prong slot, and at least one prong portion includes a notch that cooperates with the receptacle for alignment. The receptacle includes a front receptacle body, a rear receptacle body with outwardly extending knobs, a receptacle base, and sidewalls having steps, protrusions, chamfers, recesses, and upwardly extending alignment sections with grooves of different cross-sectional shapes.

Description

Attorney Docket No.: HI24-074PCTCPO CONNECTOR AND RECEPTACLE WITH O E-PIECE MOLDED RECEPTACLE D HINGED COVER BACKGROUND

[0001] This application claims the benefit of priority of U. S. Provisional Application Serial No. 63 / 725,026 filed on November 26, 2025, the content of which is relied upon and incorporated herein by reference in its entirety.BACKGROUND

[0002] The present disclosure generally relates to connectors and receptacles for co-packaged optics and related products, elements, methods and systems.

[0003] The field of Silicon Photonics (SiP) has been in development for several years and some products have been commercialized and more are under active development. In SiP, silicon is used as the optical medium, primarily in the near infrared (NIR) wavelength band around wavelengths of 1.31 μm and 1.55 μm, which are used in telecommunications.

[0004] Some advantages of SiP are the possibilities to use existing semiconductor fabrication methods and infrastructure and the integration of electronics and photonics into a single chip such as photonic integrated circuits (PICs) or at least into components that work closely together.

[0005] One of the problems that has not yet been finally solved is a method of injecting or extracting light into / out of the SiP chips. In telecommunications, light is usually transported in fibers, which now have to be coupled to the SiP PICs. Here, three methods can be distinguished. The first, edge coupling, during which waveguides of the SiP chip end are interfaced with at the edge (side) of the SiP chip. The second grating coupling, during which the PICs use grating couplers as an interface, where the light path is close to perpendicular to the surface of the chip. Grating couplers can be located anywhere on the chip’s surface.?\nd the third is evanescent coupling. For evanescent coupling, the waveguide in the silicon is brought into close proximity with a glass waveguide so that the light can couple evanescently from the silicon to the glass and vice versa.Attorney Docket No.: HI24-074PCT

[0006] One of the difficulties with coupling light to SiP PICs is the difference in mode field diameters. Single mode fibers have a mode field diameter of about 10 pm, while modes in silicon waveguides may be of submicron dimensions because of the large refractive index of silicon (about 3.5), which leads to high losses if the fibers are coupled directly to the SiP waveguides. To reduce these losses, mode converters are required to scale the modes of the SiP to the size of the fiber modes.

[0007] While grating couplers can be designed such that they easily couple to single mode fibers, they have a limited bandwidth, so that they cannot support different wavelengths (e.g., for WDM applications). Also, the fiber orientation perpendicular to the surface of the chip poses limits on the geometry / arrangements, in which these chips may be used.

[0008] Edge couplers require separate mode field converters to be able to couple to fibers. These may be realized in the silicon, as an additional interposer chip, where the conversion is realized through changing the waveguide size along the length, or through imaging optics.

[0009] With the evanescent coupling, the mode field conversion can already be built into the geometry of the glass waveguides, to which fibers may then directly be coupled.

[0010] For these reasons, among others, there is a need for improved connectors and receptacles for co-packaged optics and related products, elements, methods and systems.SUMMARY

[0011] Disclosed herein are various embodiments of connectors and receptacles for co-packaged optics and related products, elements, methods and systems. These embodiments include an assembly, particularly for co-packaged optics applications, having a receptacle that holds a fiber array unit (hereinafter “FAU”) assembly / connector. The assembly includes hinged cover coupled to the receptacle that latches in place and locates the FAU assembly / connector, using various alignment elements and features such as grooves, notches, slots, etc. The receptacle is preferably configured to adhesively attach to one or more photonic integrated circuits, either individually or in groups. The receptacle is preferably manufactured as a one-piece molded component included in a receptacle. The assembly also can include a prism attached to the receptacle, and a cover moveably attached to the receptacle. In preferredAttorney Docket No.: HI24-074PCTembodiments, the cover provides a downward force to the FAU by means of its flexibility and a soft pad (e.g. Kapton tape) attached to the FAU assembly / connector to facilitate the distribution of applied loads.

[0012] Aspects of the present disclosure also relate to mechanical attachment assemblies that allow removable attachment of a multi -fiber FAU to a surface emitting silicon PIC. Such assemblies can include a receptacle which is permanently attached to the PIC and a hinged carrier or cover which accepts the FAU assembly / connector, provides coarse alignment, and secures the FAU in place to prevent discontinuity of the optical signal path in use. Some advantages of this type of assembly structure are molding the receptacle as one component, with precision alignment features, e.g. v-grooves, integrated to the receptacle. Including these features can add robustness by eliminating fragile glass structures, reducing complexity, and potentially reducing cost.

[0013] One aspect of the disclosure relates to an assembly for co-packaged optics including a cover and a receptacle configured to receive and retain an FAU assembly / connector on a board. The receptacle has a front receptacle body, a rear receptacle body, a receptacle base, and sidewalls that together define multiple alignment elements and features for positioning the FAU assembly / connector and associated optical elements such as a prism. The receptacle base includes upwardly extending alignment sections having grooves with different cross-sectional shapes, and the base is recessed relative to surrounding walls so that the FAU assembly / connector is supported in a controlled position.

[0014] According to another aspect, a cover includes a lower cover portion with arms that couple to the receptacle and a main cover portion that extends over the receptacle. The arms have curved arm sections and coupling portions with apertures that receive outwardly extending knobs on the receptacle to secure the cover to the receptacle. The main cover portion has upper and lower cover surfaces separated by a cover thickness, along with front and rear cover surfaces and cover sides. Prongs extend from the cover sides, each prong having two prong portions separated by a prong slot, and at least one prong portion includes a notch. These features cooperate with the receptacle to facilitate coupling, positioning, and alignment of the cover relative to the receptacle.

[0015] According to another aspect, the front receptacle body includes a rear body wall with an elongated slot configured for positioning or insertion of a prism, receptacle body sidewalls withAttorney Docket No.: HI24-074PCTsteps, upwardly and outwardly extending protrusions, chamfers, and recesses, and a front body wall forming additional steps and a recess with the receptacle base. Together, these alignment elements and features provide mechanical guidance and seating for the FAU assembly / connector. In preferred embodiments, the receptacle is molded from liquid crystal polymers or polyetheretherketone, optionally with glass filler, so that the expansion behavior in the molding flow direction can be configured to match the coefficients of thermal expansion of silicon photonic integrated circuits and boro-silicate glass FAUs. The receptacle can be attached with adhesive only on the v-groove side to minimize disturbance of the FAU due to thermal expansion.

[0016] According to yet another aspect, a system for co-packaged optics includes the assembly, the FAU assembly / connector, a platform coupled between the receptacle and the board, and a prism positioned in the elongated slot. The cover is movable between open and closed positions, and the overall system provides open areas in which a tool such as a pincer or tweezer can be positioned for lifting the cover. Coarse alignment features on the receptacle interact with the cover to help keep the FAU in position while the cover is closed.

[0017] Additional aspects of the disclosure describe: one-piece molded receptacle (replacing glass / plastic or glass / metal hybrid) allowing for smaller size and reduced complexity, and increased robustness by eliminating fragile glass components. This approach also allows a lower overall height than other designs. Kapton tape (about 0.075 thick) may also be incorporated into the overall system to provide compliance in the system, reducing the overall stack height of the device. Clearance for pick and place device pincers to grab the FAU assembly / connector and position it and hold it in place while the cover is closed to secure it. Coarse alignment features in the receptacle to help keep the FAU assembly / connector positioned until the cover is closed. Although the device is shown with 20 fibers in one row, it is anticipated it can be scaled to higher single or multiple row fiber counts. A 1x36 version of fibers and other configurations are also options.

[0018] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.Attorney Docket No.: HI24-074PCT

[0019] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments, and together with the description serve to explain principles and operation of the various embodiments.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 illustrates an assembly for co-packaged optics, including a receptacle, in accordance with embodiments disclosed herein;

[0021] FIGs. 2A and 2B illustrate an assembly for co-packaged optics, including a receptacle, a cover, and an FAU assembly / connector in accordance with embodiments disclosed herein;

[0022] FIG. 3 is a cross-sectional view of the assembly shown in FIG. 2B with the cover in a closed position;

[0023] FIG. 4 illustrates a receptacle element of an assembly in accordance with embodiments disclosed herein;

[0024] FIGs. 5A and 5B illustrate an assembly an assembly for co-packaged optics, including a receptacle, a cover, and an FAU assembly / connector in accordance with embodiments disclosed herein;

[0025] FIG. 6 is a detail view of a portion of a fiber array unit in accordance with embodiments disclosed herein; and

[0026] FIG. 7 is a top view of a portion of an assembly for co-packaged optics, including a receptacle, a cover, and an FAU assembly / connector in accordance with embodiments disclosed herein.

[0027] The figures are not necessarily to scale. Like numbers used in the figures may be used to refer to like components. However, it will be understood that the use of a number to refer to aAttorney Docket No.: HI24-074PCTcomponent in a given figure is not intended to limit the component in another figure labeled with the same number.DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the disclosure will now be described with particular reference to the drawings. Exemplary embodiments of the present disclosure may take on various modifications and alterations without departing from the spirit and scope of the disclosure. Accordingly, it is to be understood that the embodiments of the present disclosure are not to be limited to the following described exemplary embodiments, but are to be controlled by the features and limitations set forth in the claims and any equivalents thereof.

[0029] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

[0030] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0031] Spatially related terms, including but not limited to, “lower,” “upper,” “beneath,” “below,” “above,” and “on top,” if used herein, are utilized for ease of description to describe spatial relationships of an element(s) to another. Such spatially related terms encompass different orientations of the device in use or operation in addition to the particular orientations depicted in the figures and described herein. For example, if an object depicted in the figures is turned over or flipped over, portions previously described as below, or beneath other elements would then be above those other elements.Attorney Docket No.: HI24-074PCT

[0032] Cartesian coordinates are used in some of the Figures for reference and are not intended to be limiting as to direction or orientation.

[0033] For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” “top,” “bottom,” “side,” and derivatives thereof, shall relate to the disclosure as oriented with respect to the Cartesian coordinates in the corresponding Figure, unless stated otherwise. However, it is to be understood that the disclosure may assume various alternative orientations, except where expressly specified to the contrary.

[0034] For the purposes of describing and defining the subject matter of the disclosure it is noted that the terms “substantially” and “generally” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation.

[0035] FIGs. 1, 2 A, 2B, and 3 illustrate an embodiment of an assembly 200 for co-packaged optics, including a cover 210 and a receptacle 240 coupled to a board B. FIG. 1 is an isometric view of the connector-receptacle assembly 200 before positioning of an FAU assembly / connector 100. FIG. 2A is an isometric view of the connector-receptacle assembly 200 with the FAU assembly / connector 100 positioned, but before full assembly. FIG. 2B is an isometric view of the connector-receptacle assembly 200 with the FAU assembly / connector 100 positioned, but after full assembly. FIG. 3 is a cross-sectional view of the connector-receptacle assembly 200 with the FAU assembly / connector 100 positioned on a platform 400, which is coupled to a prism P and the board B, after full assembly. The assembly 200 is shown positioned on a board B for use in co-packaged optics applications. The assembly 200 is configured to include a plurality of alignment features that facilitate coupling to an FAU / FAU connector as will be further described. Alignment features can include grooves, planar surfaces, notches, or any other mechanical features that could be configured to facilitate alignment with one or more components of an FAU or FAU assembly. Accordingly, the embodiments disclosed herein should not be construed as limiting.

[0036] The cover 210 includes a lower cover portion 212 and a main cover portion 220. The lower cover portion 212 includes two arms 214a, 214b. Each arm includes a curved arm section 216a, 216b and coupling portions 215a, 215b, substantially perpendicular to each curvedAttorney Docket No.: HI24-074PCTarm section. Each coupling portion 215a, 215b is configured to mate with a portion of the receptacle 240, as shown particularly in FIG. 1. Specifically, each coupling portion 215a, 215b includes an aperture 217a, 217b configured such that a portion of the receptacle 240 can be inserted therein, as will be further described.

[0037] The main cover portion 220 includes an upper cover surface 222 with a ridge 223 disposed therein, and a lower cover surface 224 positioned a distance away from the upper cover surface 222 by a cover thickness Ct2. The cover 210 further includes a front cover surface 226, a rear cover surface 228 positioned a distance away by the overall length of the cover. Extending from cover sides 231a, 231b is a plurality of prongs 230a, 230b that further facilitates coupling of the cover 210 with the receptacle 240, Each prong preferably comprises two prong portions 232a, 232b, 234a, 234b, having a prong slot 236a, 236b therebetween. The prong portions 232a, 232b, 234a, 234b have substantially the same overall length. Each second prong portion 234a, 234b preferably includes a notch 235a, 235b, which is configured to further facilitate coupling and / or alignment of the cover 210 with the receptacle 240.

[0038] Referring particularly to FIGs. 1 and 4, the receptacle 240 includes a front receptacle body 241 and a rear receptacle body 243, which are preferably integral and molded in a one- piece configuration. The rear receptacle body 243 includes outwardly extending knobs 245a, 245b configured for insertion into apertures 217a, 217b of the lower cover portion 212. The rear receptacle body 243 further includes a front section 246 configured to integrally engage with the front receptacle body 241.

[0039] As shown in FIG. 4, the front receptacle body 241 includes a plurality of alignment elements and features. The front receptacle body 214 comprises a rear body wall 250, receptacle body sidewalls 260, 270, a receptacle base 280, and a front body wall 290. The rear body wall 250 includes an elongated slot 252, which can be used for positioning and / or insertion of optical elements such as a prism P (FIG. 4). Receptacle body sidewall 260 includes various alignment elements and features such as steps 262, 264, upwardly extending protrusion 266, outwardly extending protrusion 267, chamfer 268, and recess 269. Receptacle body sidewall 270 also includes various alignment elements and features, such as steps 272, 274, upwardly extending protrusion 276, outwardly extending protrusion 277, chamfer 278, and recess 279.Attorney Docket No.: HI24-074PCT

[0040] The receptacle base 280 also includes various alignment elements and features such as an upwardly extending alignment section 281, having a groove 282 with a substantially v-shaped cross-section and an upwardly extending alignment section 283, having an alignment groove 284 with a substantially u-shaped cross-section. The receptacle base 280 is also recessed such that its uppermost surface 286 is positioned below the uppermost surfaces of the rear body wall 250, receptacle body sidewalls 260, 270, and the front body wall 290. The front body wall 290 integrally engages with the receptacle base 280 to form steps 292, 294, and a recess 296.Together all the aforementioned of alignment elements and features provide for engagement with an FAU assembly / connection, as particularly shown in FIGs. 2A, 2B, and 4.

[0041] Referring particularly to FIGs. 2A, 3, 5A, 5B, and 6, an exemplary embodiment of an FAU assembly / connector 100 is shown positioned within and coupled to the connector-receptacle assembly 200 to form a system 300 for use in co-packaged optics applications. The FAU assembly / connector 100 includes a compliant pad 130, an upper FAU element 110, a lower FAU element 120, and a microlens array 140. The upper FAU element 110 includes a plurality of centrally-located v-grooves 112 disposed therein for positioning or holding one or more fibers F. The upper FAU element additionally includes two end v-grooves 114a, 114b, which may be used for positioning of alignment elements such as rods or pins 150a, 150b, for example. The lower FAU element 120 also includes a plurality of centrally-located v-grooves 122 disposed therein for positioning or holding one or more fibers F. Exemplary FAUs, FAU assemblies / connectors are shown and described, inter alia, in US Patent Nos. 10,942,316, 11,194,107, 11,586,000, 11,567,285, and 11,415,753, which are incorporated herein by reference.

[0042] FIG. 7 illustrates a top view of the system 300, including the FAU assembly / connector 100 and the assembly 200 for co-packaged optics applications. Here, the position of the cover with respect to the receptacle is clearly seen. Specifically, the overall system provides open areas in which a tool, such as a pincer or tweezer, can be positioned for lifting of the covers from a closed position to an open position.

[0043] Preferred materials for the receptacle include liquid crystal polymers (LCPs) and polyetheretherketone (PEEK). Such materials, particularly those with glass filler, areAttorney Docket No.: HI24-074PCTanisotropic and expand less in a molding flow direction and more in the cross-flow direction with temperature. In the flow direction, these types of materials can be configured to match the coefficients of thermal expansion (CTEs) for silicon PICs and boro-silicate glass FAUs. In preferred embodiments, the receptacle could be molded with the flow direction laterally across the receptacle to minimize differential CTE effects between the silicon PIC, glass FAU and plastic receptacle. Potentially, the receptacle could be attached with adhesive only on the v-groove side which would minimize disturbance of the FAU due to CTE. Coarse alignment features which interact with the FAU cover to help keep the FAU in position while the cover is closed.

[0044] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the disclosure. Since modifications, combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the disclosure may occur to persons skilled in the art, the embodiments disclosed herein should be construed to include everything within the scope of the appended claims and their equivalents.

Claims

Attorney Docket No.: HI24-074PCTClaimsWhat is claimed is:

1. An assembly for co-packaged optics, comprising:a receptacle configured to receive an FAU assembly / connector; and a cover secured to the receptacle; wherein the cover includes a lower cover portion having two arms with curved arm sections and coupling portions, each coupling portion including an aperture configured to receive a portion of the receptacle, and a main cover portion having an upper cover surface and a lower cover surface spaced apart by a cover thickness, andwherein the receptacle includes a rear receptacle body and a front receptacle body, a receptacle base, and receptacle body sidewalls, the receptacle base including upwardly extending alignment sections having grooves of different cross-sectional shapes, and the receptacle being configured so that the alignment sections and grooves provide alignment for the FAU assembly / connector.

2. The assembly of claim 1, wherein each coupling portion of the lower cover portion is substantially perpendicular to the corresponding curved arm section and is configured to engage an outwardly extending knob of the rear receptacle body through the aperture.

3. The assembly of claim 1, wherein the main cover portion further includes a front cover surface, a rear cover surface, and cover sides extending between the front and rear cover surfaces, the upper cover surface including a ridge disposed therein.

4. The assembly of claim 1, wherein the cover includes prongs extending from the cover sides, each prong comprising two prong portions with a prong slot therebetween.

5. The assembly of claim 4, wherein at least one of the prong portions includes a notch confi gured to facilitate coupling and ali gnment of the cover with the receptacle.Attorney Docket No.: HI24-074PCT6. The assembly of any of claims 1 to 5, wherein the rear receptacle body includes outwardly extending knobs configured for insertion into the apertures of the coupling portions of the lower cover portion.

7. The assembly of any of claims 1 to 6, wherein the receptacle includes a rear body wall having an elongated slot configured for positioning or insertion of a prism.

8. The assembly of any of claims 1 to 7, wherein the receptacle body sidewalls include steps, upwardly extending protrusions, outwardly extending protrusions, chamfers, and recesses forming alignment elements for the FAU assembly / connector.

9. The assembly of any of claims 1 to 8, wherein the receptacle base is recessed such that an uppermost surface of the receptacle base is positioned below uppermost surfaces of the rear body wall, the receptacle body sidewalls, and a front body wall, and wherein the alignment sections comprise a first alignment section having a groove with a substantially v-shaped cross-section and a second alignment section having an alignment groove with a substantially u-shaped cross-section.

10. A system for co-packaged optics, comprising:a board;a platform coupled to the board;a receptacle positioned on the platform;a cover coupled to the receptacle and movable between an open position and a closed position; andan FAU assembly / connector received in the receptacle;wherein the receptacle includes a rear body wall having an elongated slot, a receptacle base having upwardly extending alignment sections with grooves of different cross- sectional shapes, receptacle body sidewalls with alignment elements including steps, protrusions, chamfers and recesses, and a front body wall forming additional steps and a recess with the receptacle base, andwherein the cover includes a lower cover portion having arms with coupling portions that engage the receptacle and a main cover portion with prongs extending from cover sides,Attorney Docket No.: HI24-074PCTsuch that the receptacle and cover cooperate to align and retain the FAU assembly / connector for co-packaged optics applications.

11. The system of claim 10, further comprising a prism positioned in the elongated slot of the rear body wall, the prism being optically coupled between the board and the FAU assembly / connector.

12. The system of claim 10 or 11, wherein the FAU assembly / connector includes a microlens array, and the upwardly extending alignment sections with the grooves are configured to position the FAU assembly / connector relative to the microlens array.

13. The system of any of claims 10 to 12, wherein the cover in the closed position extends over the FAU assembly / connector and the receptacle to hold the FAU assembly / connector in position, and the system provides open areas adjacent the cover in which a tool can be positioned for lifting the cover from the closed position to the open position.

14. The system of any of claims 10 to 13, wherein the rear receptacle body and the front receptacle body are integral and molded in a one-piece configuration, and the rear receptacle body includes outwardly extending knobs inserted into apertures of the coupling portions of the lower cover portion.

15. The system of any of claims 10 to 14, wherein the receptacle is formed from a material selected from liquid crystal polymers and poly etheretherketone, and the receptacle is molded with a flow direction laterally across the receptacle to configure thermal expansion behavior relative to silicon photonic integrated circuits and boro-silicate glass FAUs.

16. The system of any of claims 10 to 15, wherein the receptacle is attached to the platform or the board with adhesive only on a side associated with a v-groove so as to minimize disturbance of the FAU assembly / connector due to differences in coefficients of thermal expansion.Attorney Docket No.: HI24-074PCT17. The system of any of claims 10 to 16, wherein coarse alignment features of the receptacle interact with the cover when the cover is in the closed position to help keep the FAU assembly / connector in position.

18. The system of any of claims 10 to 17, wherein the prongs extending from the cover sides include prong portions with prong slots and notches that engage portions of the receptacle to provide additional coupling and alignment of the cover relative to the receptacle.

19. The system of any of claims 10 to 18, wherein the FAU assembly / connector is seated against steps and recesses of the front body wall and the receptacle base so that the FAU assembly / connector is at least partially surrounded by the rear body wall, the receptacle body sidewalls, and the front body wall.

20. The system of any of claims 10 to 19, wherein the grooves of the alignment sections having substantially v-shaped and u-shaped cross-sections are configured to receive portions of the FAU assembly / connector so as to establish alignment between the FAU assembly / connector and the receptacle.

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