Patent Description:
Next generation server high speed communication protocols are expected to rely heavily on optical interconnect architectures. As such, high-density interconnect substrate packages need to accommodate multiple photonic devices. Currently, bridge architectures (e.g., embedded multi-die interconnect bridge (EMIB) architectures) are used to support multi-chip packaging with photonic devices connected to the silicon logic die through the bridge die. In this configuration, fiber bundles are attached to the photonic IC from the side (e.g., with a V-groove connection or a multi-lens array).

Assembly of these fiber bundles is non-trivial due to the stringent alignment requirement which is exacerbated by the undulation and warpage of standard organic substrate packages. One proposal is to use glass cored substrates to provide a flatter, more rigid starting material. However, the addition of organic layers and plating steps can increase the final undulation and warpage that the photonic components see. <CIT> relates to an optical fiber array and its fabrication method which aims to increase endurance by increasing adhesive force between an adhesive agent and a V-groove block and a glass cover. <NPL>, relates to waveguides for low-cost interconnection use. <CIT> relates to techniques for forming fiber devices that engage fibers to a substrate with similar material properties. <CIT> relates to an optical printed circuit board which includes an insulation layer, an optical waveguide filled in the insulation layer and an optical device buried in the insulation layer and disposed on the same plane as the optical waveguide.

Described herein are electronic packages with glass substrates with embedded waveguides for photonics connections, in accordance with various embodiments. In the following description, various aspects of the illustrative implementations will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the illustrative implementations. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative implementations.

Various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present invention, however, the order of description should not be construed to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.

As noted above, optical interconnect architectures are needed for high speed communication protocols for next generation server products. Existing architectures for enabling optical interconnects are limited. Particularly, the warpage and deformation present in organic packaging architectures makes the alignment and attachment of optical interconnects in the package difficult and low yielding.

Accordingly, embodiments disclosed herein include package substrates that are glass. The glass substrates may improve planarity and reduce warpage. In some embodiments, the optical interconnects are made before any organic layers are provided over the glass substrate. In some embodiments, optical components (e.g., photonics integrated circuits (PICs), optics modules (e.g., lenses, etc.) may be placed in recesses into the glass substrate. Optical connections between the optical components may be made by embedded optical waveguides. In some embodiments, the optical waveguides are formed with a direct write process. In a direct write process a laser is scanned over portions of the glass substrate where an optical waveguide is needed. The laser can produce a change in the microstructure of the glass that provides an increase in the refractive index. In other embodiments, the optical waveguides are formed with a lithographic patterning process. A second glass substrate may then be adhered to the underlying glass substrate so that the optical waveguides are between the pair of glass substrates.

Referring now to <FIG>, a cross-sectional illustration of an electronic package <NUM> is shown. The electronic package <NUM> comprises a glass substrate <NUM>. The glass substrate <NUM> may have any glass formulation. The use of a glass substrate <NUM> improves the rigidity and planarity of the electronic package <NUM>. As such, it is easier to integrate optical components with proper alignment. The glass substrate <NUM> may have a thickness between approximately <NUM> and approximately <NUM>,<NUM>. Though, it is to be appreciated that thinner or thicker glass substrates <NUM> may also be used.

In an embodiment, recesses may be formed into the top surface of the glass substrate <NUM>. In <FIG>, a first recess <NUM> and a second recess <NUM> are provided into the glass substrate <NUM>. In the illustrated embodiment, the depths of the first recess <NUM> and the second recess <NUM> are substantially equal. However, in other embodiments, the first recess <NUM> and the second recess <NUM> may have different depths. In an embodiment, the first recess <NUM> is towards a middle of the glass substrate <NUM>, and the second recess <NUM> is at an edge of the glass substrate <NUM>. In an embodiment, through glass vias <NUM> may be provided below the first recess <NUM>. Through glass vias (not shown) may also be provided from the top surface of the glass substrate <NUM> to the bottom surface of the glass substrate <NUM>.

In an embodiment, photonics components may be placed into the first recess <NUM> and the second recess <NUM>. For example, an optics module <NUM> may be placed in the second recess <NUM>. The optics module <NUM> may include optics features to couple the electronic package to external optical fibers (not shown). For example, the optics module <NUM> may comprise lenses, optical fibers, mechanical features for aligning fibers, and the like. In an embodiment, a PIC <NUM> may be placed in the first recess <NUM>. The PIC <NUM> has circuitry and functionality to convert signals between an optical regime and an electrical regime. The electrical side of the PIC <NUM> may be connected to a die <NUM> by interconnects <NUM>. The die <NUM> may be a logic die, an FPGA, an SoC, or the like. The die <NUM> may be provided over a top surface of the glass substrate <NUM>.

In an embodiment, the optics module <NUM> is optically coupled to the PIC <NUM> by an embedded optical waveguide <NUM>. The optical waveguide <NUM> may be entirely embedded in the glass substrate <NUM>. That is, the glass substrate <NUM> surrounds and entire perimeter of the optical waveguide <NUM>. The optical waveguide <NUM> may be substantially the same material as the glass substrate <NUM>. However, the optical waveguide <NUM> has been treated in order to change the refractive index to be higher than the surrounding glass substrate <NUM>. For example, a laser treatment of portions of the glass substrate <NUM> may result in the microstructure of the optical waveguide <NUM> being different than a microstructure of the glass substrate <NUM>. In some embodiments, the optical waveguide <NUM> may have a substantially crystalline microstructure or partially crystalline microstructure, and the glass substrate <NUM> may have a substantially amorphous microstructure. In an embodiment, the optical waveguide <NUM> may extend from a sidewall of the first recess <NUM> to a sidewall of the second recess <NUM>.

Additionally, while a single optical waveguide <NUM> is shown, it is to be appreciated that a plurality of optical waveguides <NUM> may optically couple the optics module <NUM> to the PIC <NUM>. In some embodiments, each of the plurality of optical waveguides <NUM> are at the same z-height in the glass substrate <NUM>. In other embodiments, the optical waveguides <NUM> may be a different z-heights in the glass substrate <NUM>.

Referring now to <FIG>, a cross-sectional illustration of an electronic package <NUM> is shown. The electronic package <NUM> in <FIG> may be substantially similar to the electronic package <NUM> in <FIG>, with the exception of there being a pair of first recesses <NUM>A and <NUM>B, and a pair of PICs <NUM>A and <NUM>B. The first PIC <NUM>A may be placed in the first recess <NUM>A and the second PIC <NUM>B may be placed in the first recess <NUM>B. Additionally, a through glass via <NUM> from the top surface of the glass substrate <NUM> to a bottom surface of the glass substrate <NUM> is shown.

In an embodiment, the first PIC <NUM>A may be optically coupled to the second PIC <NUM>B by a second optical waveguide <NUM>B. In an embodiment, the second optical waveguide <NUM>B may be at the same z-height within the glass substrate <NUM> as the first optical waveguide <NUM>A between the first PIC <NUM>A and the optics module <NUM>. In other embodiments, the second optical waveguide <NUM>B and the first optical waveguide <NUM>A may be different z-heights. The second optical waveguide <NUM>B may be substantially similar to the first optical waveguide <NUM>A. For example, the second optical waveguide <NUM>B may have a crystalline or partially crystalline microstructure that provides a higher refractive index than the surrounding glass substrate <NUM>.

Referring now to <FIG>, a series of cross-sectional illustrations depicting a process for forming an electronic package with a glass substrate with embedded optical waveguides is shown.

Referring now to <FIG>, a cross-sectional illustration of the glass substrate <NUM> is shown, in accordance with an embodiment. In an embodiment, the glass substrate <NUM> may have any suitable glass formulation. The glass substrate <NUM> may have a thickness between approximately <NUM> and approximately <NUM>,<NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass substrate <NUM> after a first recess <NUM> and a second recess <NUM> are formed into the glass substrate <NUM> is shown. The first recess <NUM> and the second recess <NUM> may be formed with any suitable material removal process, such as an etching process. In a particular embodiment, a laser assisted etching process may be used to form the first recess <NUM> and the second recess <NUM>.

In an embodiment, the first recess <NUM> is entirely within a perimeter of the glass substrate <NUM>. As such, the first recess <NUM> may have four sidewalls. The second recess <NUM> may be at an edge of the glass substrate <NUM>. As such, the second recess <NUM> may have fewer than four sidewalls (e.g., three sidewalls). In the illustrated embodiment, the first recess <NUM> and the second recess <NUM> are shown as having the same depth into the glass substrate <NUM>. However, in other embodiments, the depths of the first recess <NUM> and the second recess <NUM> may be non-uniform. In the illustrated embodiment, the sidewalls of the first recess <NUM> and the second recess <NUM> are substantially vertical. In other embodiments, the sidewalls may be sloped so that the recesses have a taper.

Referring now to <FIG>, a cross-sectional illustration of the glass substrate after the placement of the optics module <NUM> and the PIC <NUM> in the recesses <NUM> and <NUM> is shown. The PIC <NUM> and the optics module <NUM> may be placed with a pick-and-place operation. In some embodiments, through glass vias <NUM> may be formed through the glass substrate <NUM> below the first recess <NUM>. The PIC <NUM> may be bonded to the through glass vias <NUM>. For example, a solder (not shown) may bond the PIC <NUM> to the through glass vias <NUM>. However, it is to be appreciated that the through glass vias <NUM> may be omitted in some embodiments. In such embodiments, the PIC <NUM> may be secured to the glass substrate <NUM> by an adhesive or the like. Pads <NUM> may be provide over a top surface of the PIC <NUM>. The pads <NUM> may be suitable for attaching to a die in a subsequent processing operation. In an embodiment, the optics module <NUM> may be secured to the glass substrate <NUM> by an adhesive (not shown) or the like.

Referring now to <FIG>, a cross-sectional illustration of the glass substrate <NUM> after formation of an optical waveguide <NUM> is shown. The optical waveguide <NUM> is formed with a direct write operation. For example, a laser is scanned across the glass substrate <NUM> in order to change the structure of the glass at a desired depth within the glass substrate <NUM>. For example, the optical waveguide <NUM> may have a crystalline or partially crystalline microstructure while the surrounding glass substrate <NUM> has a substantially amorphous microstructure. The change in the microstructure may result in a change in the refractive index of the optical waveguide <NUM>. Particularly, the refractive index of the optical waveguide <NUM> may be higher than the refractive index of the glass substrate <NUM>.

The use of a direct write process to form the optical waveguides <NUM> is particularly beneficial. This is because the direct write process can account for any misalignment between the PIC <NUM> and the optics module <NUM>. That is, if one or both of the PIC <NUM> and the optics module <NUM> are misaligned, the laser scan pattern can be easily modified to accommodate the misalignment.

Referring now to <FIG>, a cross-sectional illustration of the glass substrate <NUM> after a die <NUM> is attached to the PIC <NUM> is shown. The die <NUM> may be any suitable die, such as a logic die, an FPGA, an SoC, or the like.

Referring now to <FIG>, illustrations of an electronic package <NUM> are shown, in accordance with an additional embodiment. Instead of an optical waveguide that is embedded in a glass substrate, the optical waveguides are provided between a pair of glass substrates.

Referring now to <FIG>, a cross-sectional illustration of an electronic package <NUM> is shown, in accordance with an embodiment. In an embodiment, the electronic package <NUM> comprises a first glass substrate <NUM>. An optical waveguide <NUM> may be provided over the first glass substrate <NUM>. The optical waveguide <NUM> may be a material that has a higher refractive index than the first glass substrate <NUM>. For example, the optical waveguide <NUM> may comprise silicon and nitrogen (e.g., SiNx). An adhesive <NUM> may be provided over the optical waveguide <NUM>. A second glass substrate <NUM> may be attached to the structure by the adhesive <NUM>. In an embodiment, a first recess <NUM> and a second recess <NUM> are provided into the stack. The first recess <NUM> and the second recess <NUM> may extend entirely through the second glass substrate <NUM>. In some embodiments the first recess <NUM> and the second recess <NUM> may also extend into the first glass substrate <NUM>. In an embodiment, a PIC <NUM> may be provided in the first recess <NUM> and an optics module <NUM> may be provided in the second recess <NUM>. The PIC <NUM> may be optically coupled to the optics module <NUM> by the optical waveguide <NUM>.

Referring now to <FIG>, a plan view illustration of the electronic package <NUM> is shown, in accordance with an embodiment. In <FIG> the second glass substrate <NUM> and the adhesive <NUM> are omitted for clarity. As shown, a plurality of optical waveguides <NUM> may be provided between the first recess <NUM> and the second recess <NUM>. For example five optical waveguides <NUM> are shown. However, it is to be appreciated that any number of optical waveguides <NUM> may be used.

Referring now to <FIG>, a series of cross-sectional illustrations depicting a process for forming an electronic package with embedded optical waveguides is shown, in accordance with an embodiment.

Referring now to <FIG>, a cross-sectional illustration of a glass layer <NUM> is shown, in accordance with an embodiment. The glass layer <NUM> may have any suitable glass formulation. Additionally, the glass layer <NUM> may have a thickness between approximately <NUM> and approximately <NUM>,<NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a waveguide layer <NUM> is deposited over the glass layer <NUM> is shown, in accordance with an embodiment. In an embodiment, the waveguide layer <NUM> may be a material that has a higher index of refraction than the glass layer <NUM>. For example, the waveguide layer <NUM> may comprise silicon and nitrogen (e.g., SiNx). The waveguide layer <NUM> may be deposited with any suitable deposition process, (e.g., sputtering, chemical vapor deposition (CVD), physical vapor deposition (PVD), or the like).

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a mask <NUM> is disposed over the waveguide layer <NUM> is shown, in accordance with an embodiment. In an embodiment, the mask <NUM> may have a pattern of the desired optical waveguides that are to be formed from the waveguide layer <NUM>. In an embodiment, the mask may be a hard mask or a soft mask. For example, a hard mask may include a copper mask, and a soft mask may include a resist or the like.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after the waveguide layer <NUM> is patterned is shown, in accordance with an embodiment. As shown, the mask <NUM> protects portions of the waveguide layer <NUM> during an etching process to form optical waveguides <NUM>. In an embodiment, the etching process may be a plasma etching process.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after the mask <NUM> is removed is shown, in accordance with an embodiment. The mask <NUM> may be removed with an ashing process or other process selective to the mask <NUM> over the optical waveguides <NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a capping layer <NUM> is disposed over the glass layer <NUM> and the optical waveguides <NUM> is shown, in accordance with an embodiment. In an embodiment, the capping layer <NUM> may have an index of refraction that is lower than the index of refraction of the optical waveguides <NUM>. In some embodiments, the capping layer <NUM> may be an adhesive. When the capping layer <NUM> is an adhesive, a second glass layer (not shown) may be attached over the capping layer <NUM>. When a second glass layer is attached, the process of forming the optical waveguides may be complete. However, in other embodiments, additional layers may be provided over the capping layer <NUM> in order to provide optical waveguides at multiple Z-heights, as shown in <FIG>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a second waveguide layer <NUM> is deposited over the capping layer <NUM> is shown, in accordance with an embodiment. The second waveguide layer <NUM> may be the same material as the optical waveguides <NUM>. For example, the second waveguide layer <NUM> may comprise silicon and nitrogen. The second waveguide layer <NUM> may be deposited with any suitable deposition process, such as sputtering.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a second mask <NUM> is formed over the second waveguide layer <NUM> is shown, in accordance with an embodiment. The second mask <NUM> may be a hardmask material or a soft mask material. The second mask <NUM> may be substantially similar to the mask <NUM> described in greater detail above.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after the second waveguide layer <NUM> is patterned to form second optical waveguides <NUM> is shown, in accordance with an embodiment. As shown, the second optical waveguides <NUM> may be directly over the optical waveguides <NUM>. Accordingly, it is to be appreciated that optical waveguides <NUM> and <NUM> may be provided at multiple Z-heights within a package substrate.

After formation of the second optical waveguides <NUM>, an additional capping layer (not shown) may be provided over the second optical waveguides <NUM>. A second glass layer (not shown) may then be provided over the second capping layer. In other embodiments, additional layers of optical waveguides may be provided by repeating the process any number of times.

Referring now to <FIG>, a series of illustrations depicting a process for forming an electronic package is shown, in accordance with an embodiment.

Referring now to <FIG>, a cross-sectional illustration of a glass layer <NUM> with optical waveguides <NUM> on a surface of the glass layer <NUM> is shown, in accordance with an embodiment. In an embodiment, the optical waveguides <NUM> may be formed with a process similar to the process described above with respect to <FIG>, and will not be repeated here.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after an adhesive <NUM> is provided over the optical waveguides <NUM> and the glass layer <NUM> is shown, in accordance with an embodiment. In an embodiment, the adhesive <NUM> has an index of refraction that is lower than the index of refraction of the optical waveguides <NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a second glass layer <NUM> is disposed over the adhesive <NUM> is shown, in accordance with an embodiment. In an embodiment, the second glass layer <NUM> may have a thickness that is substantially equal to a thickness of the glass layer <NUM>. In other embodiment, the second glass layer <NUM> may have a thickness that is different than that of the glass layer <NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after the formation of a first recess <NUM> and a second recess <NUM> is shown, in accordance with an embodiment. The cross-section in <FIG> is along the line <NUM>-<NUM>' in <FIG>. That is, the cross-section in <FIG> is along the length of one of the optical waveguides <NUM>. As shown, the first recess <NUM> and the second recess <NUM> extend through the second glass layer <NUM>. The first recess <NUM> and the second recess <NUM> may also extend into the glass layer <NUM>. In the illustrated embodiment, the first recess <NUM> and the second recess <NUM> are substantially the same depth. In other embodiments, the first recess <NUM> and the second recess <NUM> may have different depths.

Referring now to <FIG>, a cross-sectional illustration of the device after a PIC <NUM> and an optics module <NUM> are inserted in the recesses <NUM> and <NUM> is shown, in accordance with an embodiment. In an embodiment, the PIC <NUM> is optically coupled to the optics module <NUM> by the optical waveguide <NUM>.

Referring now to <FIG>, a series of illustrations depicting a process for forming an electronic package is shown, in accordance with an embodiment. In the embodiment shown in <FIG>, improved control of the z-height alignment of the optical waveguide is provided compared to embodiments where the recess depth sets the z-height of the optical waveguide relative to optical components. Instead, the bottom glass layer is used as an etchstop for the recesses and a first layer is used to set the height of the optical waveguides. This provides improved control since thickness control of material deposition is more precise than depth control of an etching process.

Referring now to <FIG>, a cross-sectional illustration of a glass layer <NUM> is shown, in accordance with an embodiment. The glass layer <NUM> may be any suitable glass formulation. The glass layer <NUM> may have a thickness between approximately <NUM> and approximately <NUM>,<NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a first layer <NUM> is disposed over the glass layer <NUM> is shown, in accordance with an embodiment. The first layer <NUM> may be a material with a low index of refraction. In a particular embodiment, the first layer <NUM> may comprise silicon and oxygen (e.g., SiOx). The thickness of the first layer <NUM> may be precisely controlled in order to set the height of the optical waveguides above the glass layer <NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a waveguide layer <NUM> is disposed over the first layer <NUM> is shown, in accordance with an embodiment. The waveguide layer <NUM> may be a material with an index of refraction that is greater than the index of refraction of the first layer <NUM>. For example, the waveguide layer <NUM> may comprise silicon and nitrogen (e.g., SiNx). The waveguide layer <NUM> may be deposited with any suitable deposition process, such as sputtering.

Referring no to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a mask layer <NUM> is provided over the waveguide layer <NUM> is shown, in accordance with an embodiment. In an embodiment, the mask layer <NUM> may be a hardmask material or a soft mask material. The mask layer <NUM> may have the pattern desired for the optical waveguides.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after the waveguide layer <NUM> is patterned to form optical waveguides <NUM> is shown, in accordance with an embodiment. In an embodiment, the optical waveguides <NUM> may be patterned with a plasma etching process or the like.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after the mask layer <NUM> is removed is shown, in accordance with an embodiment. The mask layer <NUM> may be removed with an ashing process or other suitable material removal process that is selective to the material of the mask layer <NUM>.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a second layer <NUM> is provided over the first layer <NUM> and the optical waveguides <NUM> is shown, in accordance with an embodiment. In an embodiment, the second layer <NUM> comprises an index of refraction that is lower than the index of refraction of the optical waveguides <NUM>. In some embodiments, the second layer <NUM> may be the same material as the first layer <NUM>. Accordingly, the high index of refraction optical waveguides <NUM> are entirely surrounded by low index of refraction materials.

Referring now to <FIG>, a cross-sectional illustration of the glass layer <NUM> after a second glass layer <NUM> is provided over the second layer <NUM> is shown, in accordance with an embodiment. In an embodiment, the second glass layer <NUM> may be any glass formulation. In an embodiment, the second glass layer <NUM> may be substantially similar to the glass layer <NUM>.

Referring now to <FIG>, a cross-sectional illustration of the structure after recesses <NUM> and <NUM> are formed is shown, in accordance with an embodiment. The cross-section in <FIG> is along the line <NUM>-<NUM>' in <FIG>. That is, the cross-sectional illustration in <FIG> is along the length of a single one of the optical waveguides <NUM>. As shown, the first recess <NUM> and the second recess <NUM> extend through the second glass layer <NUM>, the second layer <NUM>, and the first layer <NUM>. The glass layer <NUM> serves as a bottom etchstop for the recesses <NUM> and <NUM>. Accordingly, the PIC <NUM> and the optics module <NUM> have a flat bottom surface on which they can be mounted. Additionally, the height of the optical waveguides <NUM> relative to the PIC <NUM> and the optics module <NUM> is precisely controlled by the height of the first layer <NUM>.

Referring now to <FIG>, an electronic system <NUM> is shown. The electronic system <NUM> comprises a board <NUM>, such as a printed circuit board (PCB). A glass substrate <NUM> may be coupled to the board <NUM> by interconnects <NUM>. In an embodiment, a PIC <NUM> and an optics module <NUM> may be provided in recesses in the glass substrate <NUM>. In an embodiment, the PIC <NUM> may be optically coupled to the optics module <NUM> by an embedded optical waveguide <NUM>. A die <NUM> may be coupled to the glass substrate <NUM> and PIC <NUM> by interconnects <NUM>. While the glass substrate <NUM> and optical waveguide <NUM> similar to the structure in <FIG> is shown in <FIG>, it is to be appreciated that any of the optical waveguide architectures described herein may be used in the electronic system <NUM>.

<FIG> illustrates a computing device <NUM> in accordance with one implementation of the invention. The computing device <NUM> houses a board <NUM>. The board <NUM> may include a number of components, including but not limited to a processor <NUM> and at least one communication chip <NUM>. The processor <NUM> is physically and electrically coupled to the board <NUM>. In some implementations the at least one communication chip <NUM> is also physically and electrically coupled to the board <NUM>. In further implementations, the communication chip <NUM> is part of the processor <NUM>.

These other components include, but are not limited to, volatile memory (e.g., DRAM), nonvolatile memory (e.g., ROM), flash memory, a graphics processor, a digital signal processor, a crypto processor, a chipset, an antenna, a display, a touchscreen display, a touchscreen 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 hard disk drive, compact disk (CD), digital versatile disk (DVD), and so forth).

The processor <NUM> of the computing device <NUM> includes an integrated circuit die packaged within the processor <NUM>. In some implementations of the invention, the integrated circuit die of the processor may be part of an electronic package that comprises a glass substrate with an optical waveguide embedded in an adhesive as set out in claim <NUM>, in accordance with embodiments described herein. The term "processor" may refer to any device or portion of a device that processes electronic data from registers and/or memory to transform that electronic data into other electronic data that may be stored in registers and/or memory.

The communication chip <NUM> also includes an integrated circuit die packaged within the communication chip <NUM>. In accordance with another implementation of the invention, the integrated circuit die of the communication chip may be part of an electronic package that comprises a glass substrate with an optical waveguide embedded in an adhesive as set out in claim <NUM>, in accordance with embodiments described herein.

Claim 1:
An electronic package (<NUM>), comprising:
a first glass substrate (<NUM>, <NUM>, <NUM>, <NUM>);
an adhesive (<NUM>, <NUM>, <NUM>, <NUM>) over the first glass substrate (<NUM>, <NUM>, <NUM>, <NUM>);
a second glass substrate (<NUM>, <NUM>, <NUM>) over the adhesive (<NUM>, <NUM>, <NUM>, <NUM>);
an optical waveguide (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) embedded in the adhesive (<NUM>, <NUM>, <NUM>, <NUM>); further characterized by
a first recess (<NUM>, <NUM>, <NUM>) through the second glass substrate (<NUM>, <NUM>, <NUM>) and the adhesive (<NUM>, <NUM>, <NUM>, <NUM>); and
a second recess (<NUM>, <NUM>, <NUM>) through the second glass substrate (<NUM>, <NUM>, <NUM>) and the adhesive (<NUM>, <NUM>, <NUM>, <NUM>).