Package with optical waveguide in a glass core

Abstract

The embodiments disclosed herein include an electronic package having a core including an optical waveguide, and a method of forming such an electronic package. In one embodiment, a package substrate includes a core and a photonic die embedded in the core. In another embodiment, the electronic package further includes an optical waveguide embedded in the core. In yet another embodiment, the optical waveguide optically couples the photonic die to an edge of the core.

Description

Technical field

[0001] Embodiments of the present disclosure relate to electronic packages, and more particularly, to package substrates with glass cores with embedded optical waveguides.

Prior technology

[0002] With the surge in demand for high-speed communication services, low-latency solutions with high data rates and bandwidth densities have emerged as key product differentiators. One high bandwidth communication architecture is optical communication. Optical communication is usually used for long distances. However, the high bandwidth and communications associated with optical interconnects are attracting more and more attention for implementing shorter distances, such as socket-to-socket, socket-to-board / memory, or board-to-board. Integrating optical components onto packages (eg, die, package substrate, socket, etc.) in a seamless manner to maximize bandwidth with a minimum loss and high density is very challenging.

[0003] Current methods for optical communication on packages rely on edge-firing lasers. This limits the beam bandwidth per cm2 because a single column of lasers is provided instead of an array (Vertical Cavity Surface Emitting Lasers (VCSELs) can do this). In addition, existing integration schemes rely on direct waveguide alignment with edge-firing lasers with very high precision. This places significant demands on assembly. Alternatively, the integration scheme includes laser die placed on the surface of the package. This is the only way the laser or photodiode die can be brought close to the edge, minimizing the need for fiber routing above the package. This leads to additional assembly accuracy and connectivity issues.

Content of invention

[0004] According to an embodiment of the present invention, a packaging substrate is specially proposed, which includes: a core; a photonic die embedded in the core; and an optical waveguide embedded in the core , wherein the optical waveguide optically couples the photonic grain to an edge of the core.

Implementation

[0029] According to various embodiments, described herein are package substrates with a glass core with embedded optical waveguides. In the following description, various aspects of the illustrative implementations will use terms commonly used by those of ordinary skill in the art to convey the content of their work to others of ordinary knowledge in the art. However, it will be apparent to those skilled in the art that the invention may be practiced using only some of the described aspects. For purposes of explanation, specific numbers, materials and configurations are set forth for a thorough understanding of such illustrative implementations. It will be apparent, however, to one having ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known features are omitted or simplified in order not to obscure such illustrative implementations.

[0030] Further, various operations will be described as multiple discrete acts or operations in a manner that is most helpful in understanding the invention, however, the order of description should not be construed to imply that these operations are necessarily sequentially dependent. In particular, these operations do not need to be performed in the order presented.

[0031] As noted above, the integration of optical interconnects within electronic packages is challenging due to architectural and assembly issues. Accordingly, embodiments disclosed herein include an optical waveguide embedded in a core of a packaging substrate. In particular, optical waveguides are fabricated in-core by a laser-assisted process. In one embodiment, a glass core is used. Glass can be exposed to a laser to produce a morphological change in the glass. For example, the exposed glass can be converted from an amorphous crystal structure to a crystalline crystal structure. A change in crystal structure results in a change in the index of refraction (making it higher) and allows total internal reflection. The depth, shape and form of the optical waveguide can be controlled by adjusting the focus of the laser and the guidance of the laser across the core. The enhanced routing architecture may be particularly beneficial in allowing VCSEL integration, as opposed to edge-firing only lasers.

[0032] A laser assisted etching process is also used to fabricate structures for routing optical signals in the core. For example, beveled features, such as beveled mirrors, can be fabricated in the core to reflect and direct optical signals to an optical transceiver (TRX) die. Additional embodiments may include the fabrication of channels along the edges of the core. The slots can optically couple the external fibers to the optical waveguides in the core.

[0033] Referring now to FIGS. 1A-1D , a series of cross-sectional views illustrating a laser-assisted etching process for forming features in a package core are shown, according to one embodiment. Laser assisted etching processes can be used to form the various features described herein (eg, conductive vias and mirrors). In addition, the initial stages of the laser-assisted etching process can be used to fabricate embedded optical waveguides. As shown in FIG. 1A , package core 105 is exposed by laser 170 . The laser 170 can be irradiated on a first surface 106 and a second surface 107 . However, in other embodiments, the laser 170 may only irradiate a single surface of the package core 105 .

[0034] In one embodiment, package core 105 may include a material capable of forming a shape change due to exposure to laser 170. For example, in the case of a glass encapsulated core 105, the morphological change may result in a transition from an amorphous crystal structure to a crystalline crystal structure. In one embodiment, package core 105 may have a thickness between 100 μm and 1,000 μm between first surface 106 and second surface 107 . However, it is to be understood that in other embodiments, greater or lesser thicknesses may also be used for package core 105 .

[0035] Referring now to FIG. 1B, a cross-sectional view of package core 105 after a morphological change has occurred is shown according to one embodiment. As shown, an exposed region 111 is provided through a thickness of the package core 105 . In one embodiment, the exposed region 111 may have an inclined sidewall 112 . That is to say, the sidewall 112 may not be substantially vertical (perpendicular to the first surface 106 and the second surface 107 ). In a particular embodiment, exposed region 111 may have an hourglass-shaped cross-section resulting from exposure on both first surface 106 and second surface 107 . An hourglass cross-section as used herein may mean a shape that begins with a first width at a first end and moves away from the first end to touch between the first end and a second end The width decreases before a minimum width in the middle, and increases in width when moving from the minimum width in the middle towards the second end. That is, the shape may have a central region of narrower width than the width of the opposite ends. In one embodiment, sidewall 112 may have a slope that is about 10° or less from vertical. Although shown with sloped sidewalls 112 , it is also understood that embodiments may include substantially vertical sidewalls, depending on the laser parameters and the material of the package core 105 .

[0036] Although shown as providing an exposed region 111 through an entire thickness of the package core 105, it will be appreciated that the laser parameters may be modified to provide different structures. For example, a blind structure can be formed. A blind structure extends into but not through package core 105 . Furthermore, although shown as being oriented substantially vertically, exposed region 111 may still be at an angle relative to a surface of package core 105 . For example, a 45° angle may be used to form beveled mirror features, as described in more detail below.

[0037] Alternatively, buried structures can also be provided by laser exposure. A buried structure is surrounded on all sides by an unexposed package core 105 to an exposed region 111 . For example, adjustments to the focus of a laser can be used to create buried features. In one embodiment, buried features can be used as optical waveguides, as described in more detail below. When used as an optical waveguide, processing can be terminated after laser exposure. To protect the optical waveguide from subsequent etching and plating processes, the optical waveguide may be covered by a mask layer or the like.

[0038] Referring now to FIG. 1C, a cross-sectional view of package core 105 is shown after removing exposed region 111 to form a hole 115 through package core 105, according to one embodiment. In one embodiment, the holes 115 may be formed by means of an etch process that is selective to the exposed region 111 over the remainder of the package core 105 . The etch selectivity of the exposed area 111 to the rest of the package core 105 may be 10:1 or greater, or 50:1 or greater. That is, some portions of the package core 105 may be etched despite being selective to the exposed area 111 , resulting in a slight reduction in the thickness of the package core 105 . In one embodiment, the etchant may be a wet etch chemical.

[0039] Referring now to FIG. 1D, a cross-sectional view of the core substrate 105 after a through hole 117 is formed in the hole 115 is shown, according to one embodiment. In one embodiment, vias 117 may be deposited by a plating process or any other suitable deposition process. In one embodiment, the holes 115 may have a maximum diameter of one of about 100 μm or less, about 50 μm or less, or about 10 μm or less. In some embodiments, the spacing between individual holes 115 in package core 105 may be between about 10 μm and about 100 μm. The small diameter and pitch (compared to traditional plated through hole (PTH) vias, which typically have a diameter of 100 μm or more and a pitch of 100 μm or more), allows for high density integration of vias.

[0040] In FIGS. 1A-1D, only a single cross-section of package core 105 is shown for simplicity. However, it is to be understood that the shape of the via 117 may take virtually any form. This is because the laser providing the shape change in package core 105 can be moved in a controllable manner. Examples of various plan views of a via 217 in a package core 205 are shown in FIGS. 2A and 2B .

[0041] Referring now to FIG. 2A, a plan view of a package core 205 with a plurality of circular vias 217 is shown, according to one embodiment. Although three vias 217 are shown, it is understood that any number of vias 217 may be provided in any configuration.

[0042] Referring now to FIG. 2B, a plan view of a package core 205 with a via 217 extending along one direction is shown, according to one embodiment. Such a via 217 may be referred to as a "via plane" or simply a "plane" herein. Via plane 217 may have a substantially uniform thickness through package core 205 while also extending in a direction as distinct from having substantially uniform width and length. As shown in FIG. 2B , the end of the via structure 217 may be a rounded surface 218 . The rounded surface can be the result of the shape of the laser exposure. That is, in some embodiments, the focal point of the laser may be substantially circular. The via plane can be used to form features such as an embedded mirror, as described in more detail below.

[0043] Referring now to FIG. 3A, a cross-sectional view of an electronic package 300 is shown according to one embodiment. In one embodiment, the electronic package includes a board 301 such as a printed circuit board (PCB). The board 301 can be coupled to a packaging base 302 via interconnects 311 . Interconnect 311 may include solder balls, sockets, or the like. A die 350 may be coupled to package body 302 by first level interconnect (FLI) 353 . Die 350 may be a compute die, a system on chip (SOC), an interposer with compute die bricks, or any other suitable die.

[0044] In one embodiment, package body 302 includes a core 305. Core 305 may be a glass core, or other optically clear material that can be processed with a laser assisted etching process, such as the one described above. In one embodiment, the via 317 may pass through a thickness of the core 305 . Vias 317 shown in FIG. 3A are shown with substantially vertical sidewalls. However, it is to be appreciated that vias 317 may have sloped sidewalls. For example, via 317 may have an hourglass cross-sectional characteristic of a laser assisted etching process.

[0045] In one embodiment, one or more optical waveguides 320 may be embedded in the core 305. Optical waveguide 320 may be a region of buried exposed glass. That is, laser exposure of the glass can result in a morphological change to provide the optical waveguide 320 . For example, core 305 may comprise amorphous glass and optical waveguide 320 may comprise crystalline glass. In one embodiment, the optical waveguide 320 may have a higher index of refraction than the core 305 . As such, total internal reflection may occur within optical waveguide 320 in order to route optical signals through core 305 .

[0046] In the illustrated embodiment, the optical waveguide 320 is oriented horizontally. That is, the optical waveguide 320 extends in a direction substantially parallel to a top surface of the core 305 . Optical waveguide 320 can optically couple a connector 340 to a TRX die 352 . As shown in FIG. 3A , the optical waveguide 320 appears to intersect the via 317 . This is done so that both features are depicted in the same cross-sectional view. However, it is to be understood that the optical waveguide 320 is interposed between the vias 317 . That is, the via 317 and the optical waveguide 320 do not intersect each other. In one embodiment, a cross-section of the optical waveguide (transverse to the plane shown) may be substantially circular or elliptical. It is to be understood, however, that other cross-sectional shapes may also be achieved depending on the laser settings.

[0047] In one embodiment, a connector 340 may be attached to one side of the package body 302. As shown in FIG. For example, an adhesive may attach the connector 340 to one or both of the core 305 and the buildup layer 331 . In one embodiment, the connector 340 may include a lens 341 for optical coupling to an external optical cable (not shown).

[0048] In one embodiment, TRX die 352 may be placed in a hole formed into core 305. The holes can be formed using a laser assisted etching process. The TRX die 352 can be embedded in a transparent filling material 351 . A transparent fill material 351 allows optical signals to pass between the TRX die 352 and the optical waveguide 320 . In one embodiment, the TRX die 352 may be an edge firing laser device. TRX die 352 can communicate with die 350 by electrical signals passing over vias and traces passing through buildup layer 331 . Power and ground can be provided to the TRX die 352 through solder balls connected to vias 317 under the TRX die 352 .

[0049] Referring now to FIG. 3B, a cross-sectional view of an electronic package 300 is shown according to an additional embodiment. The embodiment shown in FIG. 3B includes vertically oriented optical waveguides 320 instead of having horizontally oriented optical waveguides 320 . In one embodiment, the optical waveguide 320 may pass through an entire thickness of the core 305 . In one embodiment, the optical path (indicated by the dashed line) is from a bottom surface of the die 350, through the top buildup layer 331, through the optical waveguide 320 in the core, and through the bottom buildup layer 331 to connector 340 . A hole 303 may be formed through the board 301 in order to allow optical connections to be located under the package body 302 .

[0050] In one embodiment, transparent filling material 354 may be formed in the hole along the optical path through buildup layer 331. In some embodiments, there are no waveguides within transparent fill material 354 . In such examples, the distance the light path travels through transparent fill material 354 is minimal (eg, about 100 μm or less) and losses are insignificant. In other embodiments, optical waveguides may be provided through buildup layer 331 to further reduce losses.

[0051] In the illustrated embodiment, there are no dedicated TRX dies. Instead, transceiver functions may be implemented on die 350 . For optical coupling to the underlying optical waveguide 320, the die 350 may have a VCSEL architecture. In this way, a 2D array of lasers or photodiodes (PDs) can be arranged to provide a much greater bandwidth density.

[0052] Referring now to FIG. 3C, a cross-sectional view of an electronic package 300 is shown according to one embodiment. The electronic package 300 may be substantially similar to the electronic package 300 in FIG. 3B , except that there is a dedicated TRX die 352 . As shown, TRX die 352 may be embedded in top buildup layer 331 . A transparent fill material 355 may surround the TRX die 352 . TRX die 352 can be electrically coupled to die 350 through traces and vias in buildup layer 331 . In other embodiments, the TRX die 352 may be disposed in a recess of the core 305 similar to the TRX die 352 in FIG. 3A . By providing TRX die 352 between optical waveguide 320 and die 350, losses are reduced compared to the embodiment in FIG. 3B. This is because the optical signal does not have to pass through the top buildup layer 331 .

[0053] The bottom end of TRX die 352 may be optically coupled to optical waveguide 320 through core 305. Similar to the embodiment in FIG. 3B , a transparent fill material 354 may fill a hole through bottom buildup layer 331 to allow optical signals to pass from optical waveguide 320 to connector 340 . Similar to the embodiment in FIG. 3B , the connector 340 may be seated in a hole 303 through the sheet 301 .

[0054] Referring now to FIG. 3D, a cross-sectional view of an electronic package 300 is shown according to an additional embodiment. The electronic package 300 in FIG. 3D may be substantially similar to the electronic package 300 in FIG. 3C except for the location of the TRX die 352 . As shown in FIG. 3D , the TRX die 352 may be embedded in the bottom buildup layer 331 . As such, only electrical signals need pass through the core 305 . Vias 317 through core 305 electrically coupling TRX die 352 to die 350 may be formed by means of a laser assisted etching process. In one embodiment, the through hole 317 may have sloped sidewalls. For example, the through hole 317 may have an hourglass-shaped cross section.

[0055] In one embodiment, the optical path from the TRX die 352 may pass through a transparent fill material 354 in the bottom buildup layer 331 and continue to the connector 340 on the bottom of the package body 300. In one embodiment, a hole 303 in the board 301 is provided for receiving the connector 340 .

[0056] Referring now to FIG. 3E, a cross-sectional view of an electronic package 300 is shown according to another embodiment. The electronic package 300 in FIG. 3E may be substantially similar to the electronic package 300 in FIG. 3D except for the placement of the TRX die 352 . TRX die 352 may be integrated into connector 340 instead of being part of package body 302 . Such an embodiment can ease the alignment of some of the TRX die 352 to the connector 340 and reduce assembly complexity. The bill of materials for the package body 302 can also be reduced by shifting the TRX die 352 to the connector 340 .

[0057] In Figures 3B through 3E, TRX die 352 with VCSEL configuration can be used to create a 2D array for optical routing. However, the vertical configuration requires providing a hole 303 in the board 301 to accommodate the connector 340 . Embodiments therefore also include a framework that allows VCSEL TRX die 352 with connector 340 to be attached to the side of package body 302 . As such, no modifications to the sheet 301 are required. An example of such an embodiment is shown in Figures 4A-4E.

[0058] Referring now to FIG. 4A, a cross-sectional view of an electronic package 400 is shown, according to one embodiment. In one embodiment, the electronic package 400 includes a board 401 connected to a package base 402 via interconnects 411 . A die 450 is connected to package body 402 by FLI 453 . In one embodiment, the packaging substrate 402 may include a glass core 405 and buildup layers 431 above and below the glass core 405 . Through-core vias 417 may be provided through a thickness of core 405 . Vias 417 may have sloped sidewalls characteristic of a laser assisted etching process. For example, the via 417 may have an hourglass-shaped cross-section.

[0059] In one embodiment, an optical waveguide 420 may be embedded in core 405. Optical waveguide 420 may be the same material as core 405, but with a different crystal structure. For example, a laser exposure process may provide optical waveguide 420 with a crystalline structure, as compared to the amorphous structure used for core 405 . Optical waveguide 420 may have a refractive index greater than that of core 405 . This provides the ability to have total internal reflection. The optical waveguide 420 can optically couple a mirror 460 to a connector 440 . Connector 440 may include a lens array 441, such as a 2D lens array.

[0060] In one embodiment, the optical waveguide 420 extends in a substantially horizontal direction substantially parallel to a surface of the core 405. In an embodiment, optical waveguides 420 may be disposed at various z-heights in core 405 . As such, a 2D array of optical waveguides 420 may be provided in some embodiments.

[0061] In one embodiment, the optical waveguide 420 may terminate proximate to an embedded mirror 460. The mirrors may be at an angle of approximately 45° relative to the horizontal surface of the core 405 . The 45° angle allows the optical signal to turn 90° to be vertically oriented so that the optical path (indicated by the dashed line) can be routed to a bottom end of the TRX die 452, which can accommodate a 2D array using a VCSEL architecture. In one embodiment, the mirror 460 can be fabricated by a laser-assisted etching process. For example, mirror 460 may be a blind hole plane formed at an angle into the core. Mirror 460 may comprise copper, although other reflective materials may also be used in some embodiments.

[0062] As shown, the end of the optical waveguide 420 stops not touching the surface of the mirror 460. If the optical waveguide 420 terminates at the mirror 460, it can complicate the manufacturability of the device. This is because the etching process used to etch the trenches for the mirror 460 also etches the connected optical waveguide 420 . Keeping the optical waveguide 420 separate from the mirror 460 ensures that the optical waveguide 420 is protected from the etching process. In one embodiment, the unexposed portion of the core 405 separates the end of the optical waveguide 420 from the mirror 460 . For example, the space between the optical waveguide 420 and the mirror 460 may be between about 5 μm and about 25 μm.

[0063] Similar to the above-described embodiments, the via 417 and the optical waveguide 420 are shown as intersecting in the figures for convenience. However, it is to be understood that the waveguide 420 is interposed between the vias 417 and that in an actual arrangement there is no intersection between the waveguide 420 and the vias 417 .

[0064] Referring now to FIG. 4B, a cross-sectional view of an electronic package 400 is shown according to an additional embodiment. Electronic package 400 in FIG. 4B may be substantially similar to electronic package 400 in FIG. 4A except that there are two mirrors 460A and 460B. This may allow a vertical separation between different sets of signals, or otherwise allow spatial separation. For example, a first set of signals can be reflected off the first mirror 460A, and a second set of signals can be reflected off the second mirror 460B. The first set of signals may be outgoing signals (eg, from one of the vertically emitted lasers), and the second set of signals may be incoming signals (eg, received by the PD). In other embodiments, the different sets of signals may be different channels or any other segmentation of the signals. Although two mirrors 460A and 460B are shown, it is understood that more than two mirrors 460 may be included in the core 405 to accommodate any number of signals.

[0065] In FIG. 4B, mirrors 460A and 460B are vertically oriented for ease of illustration. A plan view in FIG. 4C shows mirrors 460A and 460B adjacent to each other. Mirrors 460A and 460B may be at the same depth in core 405, or may be at different depths. TRX die 452 is shown unshaded so as not to obscure the mirror 460 below. As indicated by the circles on each mirror 460, the optical signals can be arranged in a 2D array in order to increase the bandwidth density. The optical signal (indicated by the dashed arrow) can exit the device when reflected by the first mirror 460A, and the optical signal can enter the TRX die 452 when reflected by the second mirror 460B.

[0066] Referring now to FIG. 4D, a cross-sectional view of an electronic package 400 is shown according to an additional embodiment. Electronic package 400 in FIG. 4D may be substantially similar to electronic package 400 in FIG. 4B except that mirrors 460A and 460B have reflective surfaces that are at a 90 degree angle to each other (ie, orthogonal to each other). As such, a first connector 440A may be located on a first edge of the core 405 and a second connector 440B may be located on a second edge of the core 405 opposite the first edge. That is, mirrors 460A and 460B reflect light in opposite directions.

[0067] Referring now to FIG. 4E, a plan view of mirrors 460A and 460B in FIG. 4D is shown, according to one embodiment. As shown, oppositely sloped mirrors 460A and 460B may be adjacent to each other. In some embodiments, mirrors 460A and 460B are at the same z-height, while in other embodiments, mirrors 460A and 460B are at different z-heights. In an embodiment, outgoing signals may be reflected off the first mirror 460A, and incoming signals may be reflected off the second mirror 460B. It is to be understood, however, that the grouping of signals between mirrors may be of any suitable configuration.

[0068] The use of laser processes to form optical waveguides allows non-traditional methods to compete for optical routing on substrates. For example, an optical waveguide may include bends or turns (ie, left and right), and / or may pass through multiple z-heights in the core (ie, up and down). 5A-5C provide examples of how optical waveguides 520 may be routed.

[0069] Referring now to FIG. 5A, a plan view of a core 505 is shown, according to one embodiment. The core 505 may include a plurality of vias 517 and a mirror 560 . Vias 517 and mirrors 560 can be fabricated by a laser assisted etching process. A plurality of optical waveguides 520 may extend from an edge of the core 505 to a mirror 560 . The optical waveguides 520 may have a first pitch P1 at the edge of the core 505 and the optical waveguides 520 may have a second pitch P2 at the mirrors 560 . The second pitch P2 may be smaller than the first pitch P1. That is, the optical waveguides 520 may fan out towards the edge of the core 505 . The larger first pitch P1 allows for easier assembly of external optical cables while still allowing a high density of optical waveguides 520 at mirror 560 .

[0070] Referring now to FIG. 5B, a cross-sectional view of a core 505 is shown, according to an additional embodiment. In the illustrated embodiment, the optical waveguide 520 is shown flexed in the vertical direction (z-direction). Similar to the fan-out in the horizontal plane shown in FIG. 5A, the optical waveguide 520 can also fan-out in the z-direction.

[0071] Referring now to FIG. 5C, a cross-sectional view of a core 505 is shown, according to an additional embodiment. As shown, the optical waveguide 520 is capable of making a 90° turn 528 . As such, mirror 560 may be omitted in some embodiments. Additionally, while making a single 90° turn, a more gradual turn or multiple turns may be made in order to maintain total internal reflection along the optical waveguide 520 .

[0072] Referring now to FIG. 6A, a cross-sectional view of a core 605 is shown, according to an additional embodiment. The core 605 may include vias 617 and a mirror 660 . Vias 617 and mirrors 660 can be formed by a laser assisted etching process. A laser assisted etching process may further be used to form trenches 671 at the edge of the core 605 . The tank 671 can accommodate the outer fibers 672 of a fiber bundle 673 . Grooves 671 align fibers 672 with optical waveguides 620 in the core. The fiber 672 can be attached to the tank by a transparent filler material 674 .

[0073] Referring now to FIG. 6B, an enlarged cross-sectional view illustrating more clearly the core 605 of the tank body 671 is shown, according to one embodiment. As shown, the ends of the slot 671 are spaced from the ends of the optical waveguide 620 . That is, a part of the core 605 is between the end of the groove 671 and the end of the optical waveguide 605 . This spacing may be between about 5 μm and about 25 μm. Maintaining this spacing allows the trenches to be etched during the etch process without simultaneously removing the morphology-altered structure of the optical waveguide 605 .

[0074] Referring now to FIGS. 7A to 7F, a series of cross-sectional views are shown illustrating a process for forming a core with a tank, according to one embodiment.

[0075] Referring now to FIG. 7A, a cross-sectional view of core 705 is shown, according to one embodiment. In one embodiment, a laser is used to expose regions 781 and 716 of core 705 . The exposed regions undergo a morphological change that makes exposed regions 781 and 716 more susceptible to an etching process. The exposed area 716 can be used for a via, and the exposed area 781 is provided to form the trench.

[0076] Referring now to FIG. 7B, there is shown a cross-sectional view of core 705 after an etching process removes exposed regions 781 and 716 to form openings 782 and 715, according to one embodiment. In one embodiment, the vertical portion of opening 782 allows for complete removal of the buried portion of exposed region 781 .

[0077] Referring now to FIG. 7C, a cross-sectional view of core 705 after via 717 is disposed in opening 715 is shown, according to one embodiment. In one embodiment, opening 782 is protected from metal deposition by a mask 783 . Mask 783 allows opening 782 to remain clear to form the trough.

[0078] Referring now to FIG. 7D, a cross-sectional view of core 705 after formation of optical waveguide 720 is shown, according to one embodiment. In one embodiment, the optical waveguide 720 may be formed by a laser exposure process similar to the laser exposure shown in FIG. 7A. As shown, the end of the optical waveguide 720 may terminate before reaching the opening 782 . Although shown as intersecting via 717, it is to be understood that via 717 does not actually intersect waveguide 720 yet.

[0079] Referring now to FIG. 7E, a cross-sectional view of core 705 is shown after buildup layer 731 is disposed over core 705, according to one embodiment. In one embodiment, the buildup layer 731 is disposed over a top surface and a bottom surface of the core 705 . The buildup layer 731 can also cover the vertical portion of the opening 782 .

[0080] Referring now to FIG. 7F, a cross-sectional view of core 705 after singulation is shown, according to one embodiment. As shown, the opening 782 is now transformed into a slot 771 that extends to the edge of the singulated core 705 . Trough 771 is sized to receive an external fiber (eg, fiber from a fiber bundle).

[0081] Referring now to FIG. 8, a cross-sectional view of an electronic package 800 is shown according to an additional embodiment. The electronic package 800 may include a board 801 and a packaging base 802 coupled to the board 801 by interconnects 811 . A die 850 can be coupled to package body 802 via FLI 853 . In one embodiment, the package base 802 includes a core 805 and buildup layers 831 . In one embodiment, vias 817 and mirrors 860 are disposed in core 805 . Vias 817 and mirrors 860 can be fabricated by means of a laser assisted etching process. The mirrors can electrically couple the optical signal passing along the optical waveguide 820 to the TRX die 852 . Optical waveguide 820 may be substantially similar to any optical waveguide according to embodiments described herein.

[0082] In one embodiment, an external connection to the optical waveguide 820 may be made by a fiber bundle 873. Individual fibers 872 may be inserted into slots 871 formed into one edge of core 805 . Fiber 872 can be secured by a transparent adhesive. Trenches 871 may be formed by a laser assisted etching process, as described above. In one embodiment, an end of the slot 871 may be separated from the optical waveguide 820 by a portion of the core 805 . Although the fiber bundle 873 and trough 871 configuration is shown with a core 805 architecture that includes a mirror 860, it is to be understood that embodiments may include fibers with any core 805 architecture according to the embodiments described herein. The beam 873 and the tank body 871 structure.

[0083] FIG. 9 illustrates a computing device 900 according to an implementation aspect of the present invention. The computing device 900 is placed with a plate 902 . Board 902 may include several components including, but not limited to, a processor 904 and at least one communication chip 906 . Processor 904 is physically and electrically coupled to board 902 . In some implementations, at least one communication chip 906 is also physically and electrically coupled to the board 902 . In a further implementation aspect, the communication chip 906 is part of the processor 904 .

[0084] These other components include, but are not limited to, volatile memory (such as DRAM), non-volatile memory (such as ROM), flash memory, a graphics processor, a digital signal processor, a cryptographic processor, a chipset, an antenna, a display, a touch screen display, a touch screen controller, a battery, an audio codec, a video codec, a power amplifier, a global positioning system ( GPS) device, a compass, an accelerometer, a gyroscope, a speaker, a camera, and a mass storage device (such as a hard disk drive, compact disc (CD), digital versatile disc (DVD), etc.).

[0085] The communication chip 906 enables wireless communication to transfer data to and from the computing device 900. The term "wireless" and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communication channels, etc., which transmit data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, but in some embodiments, the associated devices may not. The communication chip 906 may implement any of a number of wireless standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 series), WiMAX (IEEE 802.16 series), IEEE 802.20, Long Term Evolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, its derivative standards, and any other wireless protocol designated as 3G, 4G, 5G, and beyond. The computing device 900 may include a plurality of communication chips 906 . For example, a first communication chip 906 can be dedicated to shorter range wireless communication such as Wi-Fi and Bluetooth, while a second communication chip 906 can be dedicated to wireless communication such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev -DO, and other agreements and other long-distance wireless communications.

[0086] The processor 904 of the computing system 900 includes an integrated circuit die packaged within the processor 904. In some implementations of the invention, according to the embodiments described herein, the integrated circuit die of the processor may be part of an electronic package comprising embedded A core of the type optical waveguide. The term "processor" may mean any device or part of a device that processes electronic data from temporary registers and / or memory to convert that electronic data into other electronic data that may be stored in temporary in memory and / or memory.

[0087] The communication chip 906 may also include an integrated circuit die packaged within the communication chip 906. According to another aspect of the invention, the integrated circuit die of the communication chip may be part of an electronic package, which according to the embodiments described herein includes a package base with a core with Embedded optical waveguides formed by means of a laser exposure process.

[0088] The above description of illustrated aspects of the invention, including what is stated in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific implementations, and examples, of the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.

[0089] These modifications can be made to the invention in light of the above detailed description. The terms used in the claims below should not be construed as limiting the present invention to the specific implementations disclosed in the specification and claims. Rather, if the scope of the present invention is to be determined as a whole by the following claims, these claims must be interpreted in accordance with established principles of claim interpretation.

[0090] Example 1: A packaging substrate comprising: a core; a photonic die embedded in the core; and an optical waveguide embedded in the core, wherein the optical waveguide converts the photonic A die is optically coupled to one edge of the core.

[0091] Example 2: The package substrate of Example 1, further comprising: electrical vias passing through a thickness of the core, wherein the electrical vias have an hourglass-shaped cross-section.

[0092] Example 3: The package base of Example 1 or Example 2, wherein the optical waveguide has a circular or elliptical cross-section.

[0093] Example 4: The packaging substrate of Examples 1 to 3, further comprising: buildup layers, and the buildup layers are located above a top surface and a bottom surface of the core.

[0094] Example 5: The packaging substrate of Examples 1-4, wherein the optical waveguide is disposed substantially parallel to a top surface of the core along an entire length of the optical waveguide.

[0095] Example 6: The package base of Examples 1 to 5, wherein the optical waveguide and the core are made of the same material, and the crystal structure of the optical waveguide is different from that of the core.

[0096] Example 7: The packaging substrate of Example 6, wherein the core is glass, and wherein the crystal structure of the optical waveguide is crystalline and wherein the crystal structure of the core is amorphous, or wherein the optical waveguide The crystal structure is amorphous and wherein the crystal structure of the core is crystalline.

[0097] Example 8: The packaging substrate of Examples 1-7, wherein a refractive index of the optical waveguide is higher than a refractive index of the core.

[0098] Example 9: An electronic package comprising: a packaging base, wherein the packaging base comprises: a core; an optical waveguide embedded in the core; and a buildup layer located on the above the core; and a die coupled to the package base, wherein the die has an optical transceiver portion, and wherein the optical transceiver portion is optically coupled to the optical waveguide.

[0099] Example 10: The electronic package of Example 9, further comprising: a transparent filler positioned in a groove passing through the build-up layer, wherein the optical transceiver part optically passes through the transparent filler coupled to the optical waveguide.

[0100] Example 11. The electronic package of Example 10, wherein the optical waveguide is vertically oriented and passes from a first surface of the core to a second surface of the core opposite the first surface.

[0101] Example 12: The electronic package of Example 11, further comprising: a second buildup layer positioned under the core; and a second transparent filler positioned through one of the second buildup layers In the second trench, wherein the second transparent fill is optically coupled to the optical waveguide.

[0102] Example 13: The electronic package of Examples 9 to 12, wherein the die is embedded in the buildup layer.

[0103] Example 14: The electronic package of Examples 9-13, further comprising: a mirror embedded in the core, wherein the optical waveguide is optically coupled to the optical transceiver portion through the mirror.

[0104] Example 15: The electronic package of Example 14, wherein the mirror is oriented about 45° relative to a surface of the core.

[0105] Example 16: An encapsulation substrate comprising: a glass core; and a plurality of optical waveguides embedded in the glass core, wherein the plurality of optical waveguides comprise optical waveguides having a different crystal structure than the glass core glass.

[0106] Example 17: The packaging substrate of Example 16, wherein the plurality of optical waveguides have a first pitch at an edge of the glass core, and a second pitch within the glass core, wherein the second pitch smaller than the first distance.

[0107] Example 18: The package substrate of Example 16 or Example 17, wherein the plurality of optical waveguides are all located at a single depth within the glass core.

[0108] Example 19: The package substrate of Example 16 or Example 17, wherein the plurality of optical waveguides are located at depths within the glass core.

[0109] Example 20: The packaging substrate of Examples 16-19, further comprising: a reflector embedded in the glass core, wherein the ends of the plurality of optical waveguides are connected to the reflector by a portion of the glass core mirror separated.

[0110] Example 21: The packaging substrate of Examples 16 to 20, further comprising: a plurality of grooves entering an edge of the glass core, wherein individual optical waveguides of the plurality of optical waveguides are in contact with the plurality of grooves The individual tanks are aligned.

[0111] Example 22: The package substrate of Example 21, wherein a portion of the glass core separates an end of the plurality of grooves from an end of the optical waveguides.

[0112] Example 23: An electronic system comprising: a board; a packaging substrate coupled to the board, wherein the packaging substrate includes: a glass core; an optical waveguide embedded in the glass core; and a connector optically coupled to the optical waveguides; and a photonic transceiver coupled to the package body, wherein the photonic transceiver is optically coupled to the optical waveguides.

[0113] Example 24: The electronic system of Example 23, wherein the connector passes through a hole in the board.

[0114] Example 25: The electronic system of Example 23, wherein the connector is attached to an edge of the glass core. [Simple description of the diagram]

[0005] FIG. 1A is a cross-sectional view of a glass core with top and bottom surfaces being exposed with a laser, according to one embodiment.

[0006] FIG. 1B is a cross-sectional view of a glass core with regions whose morphology has been altered by a laser, according to one embodiment.

[0007] FIG. 1C is a cross-sectional view of a glass core with a through hole passing through a thickness of the glass core, according to one embodiment.

[0008] FIG. 1D is a cross-sectional view of a glass core with a through hole passing through the thickness of the glass core, according to one embodiment.

[0009] FIG. 2A is a plan view of a glass core with a plurality of circular through holes, according to one embodiment.

[0010] FIG. 2B is a plan view of a glass core with a vertical via plane, according to one embodiment.

[0011] FIG. 3A is a cross-sectional view of an electronic package with a horizontal optical waveguide embedded in a core of a package base, according to one embodiment.

[0012] FIG. 3B is a cross-sectional view of an electronic package with a vertical optical waveguide embedded in a core of the package base, according to one embodiment.

[0013] FIG. 3C is a cross-sectional view of an electronic package with a vertical optical waveguide between a transceiver die and a connector, according to one embodiment.

[0014] FIG. 3D is a cross-sectional view of an electronic package with a transceiver die on a bottom end of a package base and a die above a top end of the package base, according to one embodiment.

[0015] FIG. 3E is a cross-sectional view of an electronic package with a transceiver die integrated with a connector, according to one embodiment.

[0016] FIG. 4A is a cross-sectional view of an electronic package with embedded optical waveguides and an embedded mirror, according to one embodiment.

[0017] FIG. 4B is a cross-sectional view of an electronic package with an embedded optical waveguide and a plurality of embedded mirrors, according to one embodiment.

[0018] FIG. 4C is a plan view of the mirror in FIG. 4B, according to one embodiment.

[0019] FIG. 4D is a cross-sectional view of an electronic package with an embedded optical waveguide and a plurality of embedded mirrors placed diagonally, according to one embodiment.

[0020] FIG. 4E is a plan view of the mirror in FIG. 4D, according to one embodiment.

[0021] FIG. 5A is a plan view of a core with embedded optical waveguides having a first pitch near an edge of the core and a mirror near a mirror, according to one embodiment. second spacing.

[0022] FIG. 5B is a cross-sectional view of a core with embedded optical waveguides passing through different z-heights in the core, according to one embodiment.

[0023] FIG. 5C is a cross-sectional view of a core with an embedded optical waveguide having a turn, according to one embodiment.

[0024] FIG. 6A is a cross-sectional view of a core with a socket for receiving a connector, according to one embodiment.

[0025] FIG. 6B is an enlarged view of the trough and the connector, according to one embodiment.

[0026] FIGS. 7A-7F are cross-sectional views illustrating a process for forming slots in a core, according to one embodiment.

[0027] FIG. 8 is a cross-sectional view of an electronic package with a core including a socket for receiving a connector, according to one embodiment.

[0028] FIG. 9 is a schematic diagram of a computing device constructed according to one embodiment.

Claims

1. An encapsulation substrate comprising: a core; a transparent filler material therein; a photonic die embedded in the transparent filler material; and an optical waveguide embedded in the core, wherein the optical waveguide is optically coupled to the photonic die through the transparent filler material and extends to one edge of the core.

2. The packaging substrate of claim 1 further includes: electrical vias that pass through a thickness of the core, wherein the electrical vias have an hourglass-shaped cross-section.

3. The packaging substrate of claim 1 or 2, wherein the optical waveguide has a circular or elliptical cross section.

4. The packaging substrate of claim 1 or 2 further comprises: stacked layers located above a top surface and a bottom surface of the core.

5. The package substrate of claim 1 or 2, wherein the optical waveguide is arranged substantially parallel to the top surface of one of the cores along the entire length of one of the optical waveguides.

6. The packaging substrate of claim 1 or 2, wherein the optical waveguide is made of the same material as the core, and wherein one of the crystal structures of the optical waveguide is different from one of the crystal structures of the core.

7. The packaging substrate of claim 6, wherein the core is glass, and wherein the crystal structure of the optical waveguide is crystalline and wherein the crystal structure of the core is amorphous, or wherein the crystal structure of the optical waveguide is amorphous and wherein the crystal structure of the core is crystalline.

8. The package substrate of claim 1 or 2, wherein the refractive index of one of the optical waveguides is higher than the refractive index of one of the cores.

9. An electronic package comprising: a package substrate, wherein the package substrate includes: a core; an optical waveguide embedded therein; a stacked layer located above the core; a transparent filler in a trench through the stacked layer; and a die coupled to the package substrate, wherein the die has an optical transceiver portion, and wherein the optical transceiver portion is optically coupled to the optical waveguide through the transparent filler.

10. The electronic package of claim 9, wherein the optical waveguide system is vertically oriented and extends from a first surface of the core to a second surface of the core opposite to the first surface.

11. The electronic package of claim 10 further comprises: a second stacked layer located beneath the core; and a second transparent filler located in a second trench passing through the second stacked layer, wherein the second transparent filler is optically coupled to the optical waveguide.

12. An electronic package as claimed in 9, 10, or 11, wherein the die is embedded in the stacked layer.

13. The electronic package of claim 9, 10, or 11 further comprises: a mirror embedded in the core, wherein the optical waveguide is optically coupled to the optical transceiver section via the mirror.

14. The electronic package of claim 13, wherein the mirror is oriented at approximately 45° relative to one of the surfaces of the core.

15. An encapsulation substrate comprising: a glass core; a plurality of optical waveguides embedded in the glass core, wherein the plurality of optical waveguides comprise glass having a crystal structure different from that of the glass core; a transparent filler material on the glass core; and a photonic die at least partially surrounded by the transparent filler material, wherein the photonic die is optically coupled to the plurality of optical waveguides through the transparent filler material.

16. The packaging substrate of claim 15, wherein the plurality of optical waveguides have a first spacing at an edge of one of the glass cores and a second spacing within the glass cores, wherein the second spacing is smaller than the first spacing.

17. The packaging substrate of claim 15 or 16, wherein all of the plurality of optical waveguides are located at a single depth within the glass core.

18. The package substrate of claim 15 or 16, wherein the plurality of optical waveguides are located at a plurality of depths within the glass core.

19. The package substrate of claim 15 or 16 further comprises: a mirror embedded in the glass core, wherein the ends of the plurality of optical waveguides are separated from the mirror by a portion of the glass core.

20. The package substrate of claim 15 or 16 further comprises: a plurality of slots entering one edge of the glass core, wherein an individual optical waveguide of the plurality of optical waveguides is aligned with an individual slot of the plurality of slots.

21. The packaging substrate of claim 20, wherein a portion of the glass core separates one end of one of the plurality of slots from the end of the optical waveguides.

22. An electronic system comprising: a substrate; a package substrate coupled to the substrate, wherein the package substrate comprises: a glass core; optical waveguides embedded in the glass core; and a connector optically coupled to the optical waveguides; a transparent filler material coupled to the package substrate; and a photonic transceiver at least partially surrounded by the transparent filler material, wherein the photonic transceiver is optically coupled to the optical waveguides through the transparent filler material.

23. The electronic system of claim 22, wherein the connector passes through one of the holes in the plate.

24. The electronic system of claim 22, wherein the connector is attached to one edge of the glass core.

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