Camera module with a folded flexible interconnect tape package

A camera module includes an image sensor die, high-density interconnect (HDI) tape, and a number of passive electronic components. The image sensor die has a first side and a second side. The first side includes a pixel array, and the second side is opposite the first side. The HDI tape is a flexible substrate coupled to the image sensor. The HDI tape is at least partially folded or bent around the image sensor to couple to the HDI tape to the first and second sides of the image sensor die. The passive electronic components are coupled to the second side of the HDI tape and provide rigidity to the camera module.

TECHNICAL FIELD

This disclosure relates generally to camera modules and in particular to camera module fabrication.

BACKGROUND INFORMATION

Various wearable products include cameras. As smaller and lighter-weight product designs emerge, product manufacturers are requesting increasingly smaller camera sizes.

DETAILED DESCRIPTION

Embodiments of a system and fabrication method for a camera module with flexible interconnect tape folded around an image sensor die are described herein. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.

Next generation products will be designed for camera modules that have smaller dimensions. Camera module dimensions may include stack height, length, and width. Examples of products that may benefit from smaller camera modules may include augmented reality (AR) glasses and virtual reality (VR) glasses.

A camera module's physical package dimensions may be reduced from those of existing cameras, by fabricating the camera module using high-density interconnect (HDI) tape folded around an image sensor die that is configured for wire bonding. The camera module includes an image sensor die, a segment of HDI tape folded around the image sensor die, and passive electronic components coupled together to form the camera module, according to an embodiment.

The HDI tape may be coupled to multiple sides of the image sensor die. The HDI tape may be folded or bent around a portion of the image sensor die to couple the HDI tape to a first and second side of the image sensor die. The HDI tape may include an opening that functions as a window for the pixel array to receive light through the HDI tape. The HDI tape may be a flexible interconnect tape having an image sensor end, a connector end, and a flexible interconnect section. The HDI tape may include traces that extend from the image sensor end to the connector end through the flexible interconnect section. The traces electrically couple the image sensor to a connector to enable external circuitry to access or communicate with the image sensor die. The HDI tape may include flexible insulator layers (e.g., 2 layers, 4 layers, 6 layers, etc.) that enclose the traces. The flexible insulator layers may include flexible polymer films. The connector may be coupled to the HDI tape and may include a number of connection pads.

The image sensor die may be electrically coupled to a first surface (e.g., a top surface or inside surface) of the HDI tape with bonding bumps. The bonding bumps may be gold stud bumps or gold plated stud bumps. The bonding bumps may be used to couple bonding pads of the image sensor die to exposed portions of traces of the HDI tape. The image sensor die may be a wire bond die having bonding pads on the same side (or surface) as a pixel array of the image sensor die. The image sensor die may be bonded to the HDI tape using flip chip die bonding techniques. For example, by wrapping a portion of the HDI tape over the bonding pads of the image sensor die, thermo-sonic (TS) bonding or thermo-compression (TC) bonding may be applied to electrically couple the image sensor die to traces within the HDI tape. Molding may be applied around a periphery of at least part of the image sensor die to protect the image sensor die. The molding and HDI tape may be sized to approximately the same footprint (e.g., length and width) of the image sensor die to maintain reduced dimensions of the overall camera module package.

The passive electronic components may be coupled to a second surface (e.g., a bottom surface) of the HDI tape. The location of the passive electronic components may be just opposite to the image sensor die on the HDI tape, so that the image sensor die and the passive electronic components are on the image sensor end of the HDI tape. The passive electronic components may include resistors, capacitors, inductors, and diodes, for example. The passive electronic components may be electrically coupled to the HDI tape using, for example, a solder paste. The passive electronic components may be covered with a layer of molding. The layer of molding may physically couple the electronic components to the HDI tape and may provide protection to the components. The layer of molding may add rigidity to the image sensor end of the camera module and may thermally conduct and dissipate heat from the image sensor die and the passive electronic components.

The apparatus, system, and method of fabrication for a camera module with folded flexible interconnect tape are described in this disclosure and enable manufacture of a low profile camera module to support operations of, for example, AR and VR glasses. These and other embodiments are described in more detail in connection withFIGS.1A-5.

FIG.1Aillustrates a perspective view of a camera module100that is fabricated with flexible interconnect tape102, in accordance with aspects of the disclosure. Flexible interconnect tape102is folded or bent around a portion of an image sensor die124to at least partially enclose image sensor die124, according to an embodiment. Flexible interconnect tape102is folded around a portion of image sensor die124to enable bonding to a wire bond image sensor die using flip chip die bonding techniques, such as thermo-sonic (TS) bonding or thermo-compression (TC) bonding. Camera module100is configured to provide a small footprint that is approximately the same as the footprint of an image sensor die to support, for example, head mounted display (HMD) applications, according to an embodiment. Camera module100includes a sensor end104, a connector end106, and a flexible interconnect section108that couples sensor end104to connector end106, according to an embodiment. Implementations of camera module100provide a small-sized, lightweight, and low-profile package that can be fabricated from existing wire bond image sensor dice. Flexible interconnect tape102extends from an image sensor end104to a connector end106, and flexible interconnect section108couples image sensor end104to connector end106, using flexible interconnect tape102, according to an embodiment.

Flexible interconnect tape102is configured to electrically couple, one or more electronic components to one or more other electronic components, according to an embodiment. Flexible interconnect tape102may be implemented as a segment of high-density interconnect (HDI) tape, according to an embodiment. Flexible interconnect tape102includes a thickness T, a width W, and a length L. Length L may refer to a length of camera module100, or length L may refer to the length of flexible interconnect tape102, which includes a portion that is folded back over image sensor die124. Thickness T may be approximately 0.07 mm to 0.18 mm. Thickness T of flexible interconnect tape102may vary based on a number of layers (e.g., 2 layers, 4 layers, 6 layers, etc.) from which it is fabricated. For example, flexible interconnect tape102may include a top layer and a bottom layer that enclose a number of traces110. The layers may be flexible insulator layers of that include, for example, flexible polymer films. Flexible interconnect tape102may include 2 layers, 4 layers, 6 layers, or more layers to enclose and sandwich one or more of layers of traces110. Traces110couple image sensor end104to connector end106, according to various embodiments. Width W of flexible interconnect tape102may vary from one end to another. Width W of flexible interconnect tape102may be a width of a connector112on connector end106, may be a width of flexible interconnect section108, and may be a width of image sensor die124on image sensor end104, according to various embodiments. Length L may include a length of image sensor end104(e.g., a length or width of an image sensor die), plus a length of connector112, plus a length of flexible interconnect section108.

Camera module100includes a partially enclosed image sensor die124coupled to flexible interconnect tape102on sensor end104, according to an embodiment. Image sensor die124includes a pixel array114that may be exposed by an opening116. Opening116may be an aperture in flexible interconnect tape102. Opening116may be formed in a portion of flexible interconnect tape102that is wrapped over a pixel array side (e.g., top side) of image sensor die124. Partially enclosing image sensor die124by wrapping flexible interconnect tape102over image sensor die124may be performed to enable bonding between bonding pads on the pixel array side image sensor die124(shown inFIGS.1B and1C), according to an embodiment. Bonding the bonding pads directly to a substrate (e.g., flexible substrate) may be referred to as flip chip bonding. Hence, wrapping flexible interconnect tape102over image sensor die124to bond to bonding pads enables a flip chip type of bonding to a wire bond die while providing a window through which pixel array114may receive light, according to an embodiment. Additionally, the stack height of passive electronic components, flexible interconnect tape102, and image sensor die124is reduced over traditional camera modules.

Molding118may be disposed on flexible interconnect tape102and at least partially around image sensor die124. Molding118is disposed around, for example, at least part of the periphery of image sensor die124to protect and immobilize image sensor die124, according to an embodiment. Molding118may be applied using transfer molding processes, and molding118may include molding materials such as: acrylic, acrylonitrile butadiene styrene (ABS), nylon polyamide (PA), polycarbonate (PC), polyethyelene (PE), polyoxymethylene (POM), polypropylene (PP), polystyrene (PS), thermoplastic elastomer (TPE), and thermoplastic polyurethane (TPU), according to various embodiments. Molding118is disposed between folded over portions of flexible interconnect tape102, according to an embodiment.

Camera module100includes a molding120that is applied to a second surface (e.g., a bottom surface) of flexible interconnect tape102on image sensor end104, according to an embodiment. Molding120at least partially encapsulates a number of electronic components that are coupled to the second surface of flexible interconnect tape102. Molding120provides rigidity to image sensor end104, protects image sensor die124from being bent or broken, and provides thermal dissipation away from the electronic components, in an embodiment. The electronic components may be passive electronic components and may include resistors, capacitors, inductors, and diodes, for example.

Connector end106includes a portion of flexible interconnect tape102, connector112, and a number of pads122. Pads122are electrically conductive pads that are coupled to traces110. Pads122are electrically coupled to image sensor die124and provide an external interface to various connections of image sensor die124(e.g., power, ground, data, communications, configuration, diagnostics, etc.), according to an embodiment.

FIG.1Billustrates a cross-sectional side view of camera module100, in accordance with aspects of the disclosure. InFIG.1B, the electronic components of camera module100are illustrated as electronic components128, according to an embodiment. Image sensor die124is coupled to a first side (or surface)126of flexible interconnect tape102, and electronic components128are coupled to a second side (or surface)130of flexible interconnect tape102, according to an embodiment.

Image sensor die124is a wire bond die that is coupled to flexible interconnect tape102using flip chip die bonding techniques, according to an embodiment. Flip chip bonding may refer to coupling bonding pads to a substrate (e.g., flexible interconnect tape102) with a number of bonding bumps (e.g., gold stud bumps, solder balls, gold plated stud bumps, etc.), for example. Typically, a wire bond die would need bonding wires coupled from the top surface bonding pads (with a small loop) to a substrate (e.g., a printed circuit board). However, wire bonding increases the stack height of a camera module because bonding wires typically require a small loop near the bonding pad to maintain space/isolation between the bonding wire and traces of the die surface. The flip chip die bonding technique of the disclosure uses a folded flexible interconnect tape102to bond to the bonding pads, which may reduce wasted space that may be caused through wire bonding techniques.

Flexible interconnect tape102includes flexible interconnect tape102A,102B, and102C. Flexible interconnect tape102A represents the portion of flexible interconnect tape102that runs along a bottom side150(e.g., opposite side of the pixel array side) of image sensor die124. Flexible interconnect tape102B represents the portion of flexible interconnect tape102that runs along a top side152(e.g., pixel array side) of image sensor die124. Flexible interconnect tape102C represents the portion of flexible interconnect tape102that is folded or bent around a peripheral side146of image sensor die124. Traces110include traces110A,110B, and110C that correspond with portions of the traces110that also extend along the bottom, top, and peripheral side146of image sensor die124, according to an embodiment. For bonding to image sensor die124, traces110B may be exposed on first side126of flexible interconnect tape102B at the locations of bonding pads134.

Image sensor die124may have multiple sides coupled to interconnect tape102, according to an embodiment. Image sensor die124may be adhered to interconnect tape102A with thin adhesive layer148to immobilize image sensor die124. Adhesive layer148may be dispensed by thermo-set/thermo-plastic adhesive. Bottom side150is the non-pixel array side of image sensor die124, and bottom side150may be adhered to flexible interconnect tape102A with adhesive layer148, according to an embodiment. Top side152is the pixel array side of image sensor die124, and top side152may be bonded to flexible interconnect tape102B using a number of bonding bumps136coupled to bonding pads134, according to an embodiment. Bonding bumps136may be aligned with exposed portions of traces110B to electrically couple traces110B to bonding pads134. Bonding bumps136may include gold stud bumps, gold plated stud bumps, or other bumps that are compatible with TS bonding or TC bonding, according to an embodiment. Image sensor die124is TS bonded or TC bonded to flexible interconnect tape102(e.g., flexible interconnect tape102B) by applying heat and ultrasonic waves (e.g., TS bonding) or by applying heat and compressive force (e.g., TC bonding).

An underfill layer154may be applied between flexible interconnect tape102B and top side152. For TS bonding, underfill layer154may be an underfill material that provides support around bonding bump136. For TC bonding, underfill layer154may be an adhesive such as non-conductive paste (NCP). In some implementations, anisotropic conductive paste (ACP) or a conductive epoxy may be used to bond traces110B to bonding bumps136and bonding pads134.

Image sensor die124includes pixel array114, and pixel array114may include a number of components. Pixel array114may include a number of pixels137that are each individually configured to convert light into electrical signals that can be transferred to traces110. Pixels137in pixel array114may be covered by a color filter array (CFA)138(e.g., red, green, blue) and microlenses140, according to an embodiment. CFA138may be configured to filter/pass particular wavelengths of light, and microlenses140may be configured to focus incident light upon individual ones of pixels137in pixel array114.

Electronic components128and molding120are configured to support operation of image sensor die124and are configured to provide rigidity to camera module100, according to an embodiment. Electronic components128and molding120are configured to support operation and reduce the likelihood of damage (e.g., bending, breaking) to image sensor die124, according to an embodiment. Electronic components128are coupled to traces110A that are accessible and exposed on second side130of flexible interconnect tape102A, according to an embodiment. Electronic components128may be passive components and may include, but are not limited to, capacitors, resistors, inductors, and diodes, according to an embodiment. Molding120may thermally conduct heat away from electronic components128, away from flexible interconnective tape102, and away from image sensor die124, according to an embodiment. Molding120may be configured to dissipate heat transferred from electronic components128, flexible interconnective tape102, and image sensor die124, according to an embodiment.

Camera module100may include cover glass142that is configured to at least partially cover image sensor die124, according to an embodiment. Cover glass142may be coupled or adhered to flexible interconnect tape102to cover and protect pixel array114, according to an embodiment. Cover glass142may be configured to create an air gap144between pixel array114and cover glass142. Air gap144defined by cover glass142may protect pixel array114from dirt, dust, or other obstacles.

FIG.1Cillustrates an example plan view of camera module100, in accordance with aspects of the disclosure. As illustrated, bonding pads134and bonding bumps136may be distributed around a periphery of pixel array114. Bonding pads134may be coupled to various components146(individually, component146A,146B, and146C) of image sensor die124. Examples of components146may include pixel array readout circuitry, processing circuitry, volatile memory, non-volatile memory, driver circuitry, etc. Bonding pads134may be coupled to components146with on-chip traces147, for example. On-chip traces147may be conductive channels that are on and within image sensor die124. On-chip traces147, bonding pads134, bonding bumps136, and traces110provide electrical coupling between pads122and components146to enable external access to features (e.g., data lines, clock signals, communication channels, etc.) of image sensor die124, according to an embodiment.

FIGS.2A-2Hillustrate a process of fabricating camera module100using flexible interconnect tape102folded around image sensor die124, in accordance with aspects of the disclosure.

FIG.2Aillustrates mounting electronic components128to flexible interconnect tape102, according to an embodiment. An advantage of using flexible interconnect tape102(e.g., HDI tape) is the ability to control tight tolerances, perform micro-vias and fine line spacing in substrate routing, which may reduce the footprint and possibly reduce the total number of layers of camera module100. Reducing the thickness of the substrate can reduce the overall height of the module. Electronic components128are passive electronic components that are coupled to exposed portions of traces110on image sensor end104of flexible interconnect tape102, according to an embodiment. Electronic components128may be soldered onto flexible interconnect tape102using, for example, a gold (Au) and tin (Sn) alloy solder paste. Electronic components128may include capacitors, resistors, inductors, and diodes, for example. Electronic components128may have a height of 0.2 mm to 0.3 mm, for example. Coupling electronic components128to traces110electrically couples electronic components128to connector112that is positioned on connector end106through traces110, according to an embodiment. Electronic components128may be coupled to traces110using solder paste have a thickness of, for example, 0.05 mm. When implemented with 2 layers (and traces110) flexible interconnect tape102may have a thickness of 0.07 mm. The thickness of the electronic components128, solder paste, and flexible interconnect tape102may be the sum of 0.2 mm, 0.05 mm, and 0.07 mm, which is 0.32 mm, for example.

FIG.2Billustrates the application of molding120over electronic components128, according to an embodiment. Molding120covers and protects electronic components128, according to an embodiment. Molding120provides rigidity to image sensor end104of flexible interconnect tape102, according to an embodiment. Molding120may also transfer and dissipate heat from flexible interconnect tape102and from electronic components128, which may support maintaining image quality during video mode. A molding thickness MT over electronic components128may be, for example, 0.1 mm thick. In one embodiment, molding thickness MT has a value in the range of 0.05 mm-0.2 mm thick. However, the layer of molding120will include a thickness of the electronic components128in addition to molding thickness MT, so that molding120at least partially fills gaps between electronic components128. Because flexible interconnect tape102may have a thickness or height of 0.07 mm, solder paste may be 0.05 mm thick, electronic components128may be 0.2 mm thick, and molding thickness MT may be 0.1 mm thick, the total thickness of these portions of camera module100may be approximately 0.42 mm thick (e.g., 0.40 mm-0.50 mm).

FIG.2Cillustrates coupling bonding bumps136to bonding pads134of image sensor die124, according to an embodiment. Bonding bumps136may be gold stud bumps, gold plated stud bumps, E-less nickel/gold alloy plated, or another conductive element or alloy. Bonding bumps136may be coupled to bonding pads134using, for example, a conductive adhesive such as ACP. Bonding bumps136may have a non-spherical shape, may be partially conical, or may be spherical (e.g., similar to a solder ball), according to various embodiments. Bonding bumps136may have a stack height of 0.03 mm, for example.

FIG.2Dillustrates coupling image sensor die124to first side126of flexible interconnect tape102, according to an embodiment. Bottom side150of image sensor die124may be coupled to flexible interconnect tape102using adhesive layer148, which may be dispensed by thermo-set or thermo-plastic adhesive, according to an embodiment. Image sensor die124may have a thickness of 0.30 mm.

FIG.2Eillustrates flexible interconnect tape102being folded over or bent around image sensor die124, according to an embodiment. Flexible interconnect tape102is folded over to partially cover top side152of image sensor die124, according to an embodiment. Flexible interconnect tape102may have a bend radius of 1.5 times the thickness of flexible interconnect tape102, so the bend radius may be 1.5 times 0.07 mm, which is approximately 0.105 mm. Flexible interconnect tape102includes opening116, but flexible interconnect tape102does not illustrate opening116inFIG.2Eto more clearly illustrate the manipulation of the tape.

FIG.2Fillustrates the bonding of image sensor die124to flexible interconnect tape102B, according to an embodiment. Image sensor die124may be bonded to flexible interconnect tape102B using thermo-sonic (TS) bonding or thermo-compression (TC) bonding, according to embodiments. TC bonding force can be reduced because bonding on a flexible tape surface can be performed with less force than needed for printed circuit board (PCB) materials. Additionally, a thinner die can be used due to better coefficient of thermal expansion (CTE) between tape and silicon and reduced bonding force. TS and TC bonding may include applying underfill layer154, which may be a conductive epoxy, a non-conductive paste (NCP), or an anisotropic conductive paste (ACP). TS bonding may then include concurrently applying heat with an ultrasonic signal to bond bonding bumps136to flexible interconnect tape102B and to cure the epoxy, NCP, or ACP. TC bonding, however, may include applying heat with compression to bond bonding bumps136to flexible interconnect tape102B, according to an embodiment.

The total height of camera module may include a combined thickness of the various components coupled together and illustrated inFIGS.2A-2F, according to an embodiment. For example, the stack height or thickness of the camera module may be the sum of 0.07 mm for flexible interconnect tape102A, 0.30 mm for image sensor die124, 0.03 mm for bonding bumps136, 0.07 mm for flexible interconnect tape102B, 0.05 mm for solder paste for passive electronic components128, 0.20 mm for passive electronic components128, 0.10 mm mold thickness MT over passive electronic components128. The stack height may have a total thickness of 0.82 mm.

FIG.2Gillustrates applying molding118around a periphery of portions of image sensor die124, according to an embodiment. A mold structure may be positioned around image sensor die124and camera module100, and the mold structure may enable mold compound to be transferred around image sensor die124. As illustrated, molding118may fill portions of the cavity between image sensor die124and flexible interconnect tape102C, for example. While molding118is applied, a number of image sensor dice may be restrained by a framework (e.g., framework400or402shown inFIG.4) that enables automated fabrication of numerous camera modules at the same time. The camera modules may be singulated (e.g., individually separated from the framework) after receiving molding118or after another process, according to various embodiments.

FIG.2Hillustrates the addition of a lens assembly304to camera module100, according to an embodiment. Lens assembly304may be configured to focus incident light onto pixel array114. Lens assembly304may include a lens306and a body308that suspends lens306a pre-determined distance from pixel array114, according to an embodiment. Lens assembly304may be attached using an active alignment (AA) process, which includes use of machine vision, pictures of camera modules, and/or alignment markers on portions of camera module100, in an embodiment. Lens assembly304may be coupled to cover glass142, which may be positioned over pixel array114to protect pixel array114, according to an embodiment. Cover glass142may be adhered to flexible interconnect tape102with an adhesive, according to an embodiment.

FIG.3illustrates process300for fabricating a camera module using flexible interconnect tape folded over a wire bond image sensor die, in accordance with aspects of the disclosure. The order in which some or all of the process blocks appear in process300should not be deemed limiting. Rather, one of ordinary skill in the art having the benefit of the present disclosure will understand that some of the process blocks may be executed in a variety of orders not illustrated, or even in parallel.

At process block302, process300mounts electronic components to a bottom surface of a flexible interconnect tape, according to an embodiment. Process block302proceeds to process block304, according to an embodiment.

At process block304, process300applies molding over the electronic components, according to an embodiment. Process block304proceeds to process block306, according to an embodiment.

At process block306, process300couples bonding bumps (e.g., gold stud bumps) to bonding pads of an image sensor die, according to an embodiment. The bonding pads may be on a surface that includes the pixel array, according to an embodiment. Process block306proceeds to process block308, according to an embodiment.

At process block308, process300couples image sensor die to a top surface of the flexible interconnect tape, according to an embodiment. The bottom side (e.g., non-pixel array side) of the image sensor die may be coupled to the flexible interconnect tape with an adhesive. Process block308proceeds to process block310, according to an embodiment.

At process block310, process300folds flexible interconnect tape over a pixel array side of the image sensor die, according to an embodiment. The flexible interconnect tape may include an opening that operates as a window to pass light onto the pixel array. Process block310proceeds to process block312, according to an embodiment.

At process block312, process300bonds image sensor die to traces of flexible interconnect tape, according to an embodiment. Process300may include TS bonding or TC bonding to electrically couple the bonding pads of the image sensor die to exposed traces of the flexible interconnect tape. Process block312proceeds to process block314, according to an embodiment.

At process block314, process300applies molding around a periphery of the image sensor die, according to an embodiment. Process block314proceeds to process block316, according to an embodiment.

At process block316, process300individually separates camera modules from one another, according to an embodiment. Process block316proceeds to process block318, according to an embodiment.

At process block318, process300attaches a lens assembly to the camera module. Process300may terminate after process block318, according to an embodiment.

FIG.5illustrates a head mounted display (HMD)500that includes a camera module509fabricated with flexible interconnect tape, in accordance with aspects of the disclosure. Camera module509is an example implementation of camera module100(shown inFIGS.1A-2H), according to an embodiment. HMD500includes frame514coupled to arms511A and511B. Lenses521A and521B are mounted to frame514. Lenses521may be prescription lenses matched to a particular wearer of HMD or non-prescription lenses. The illustrated HMD500is configured to be worn on or about a head of a user of the HMD.

InFIG.5, each lens521includes a waveguide550to direct image light generated by a display530to an eyebox region for viewing by a wearer of HMD500. Display530may include an LCD, an organic light emitting diode (OLED) display, micro-LED display, quantum dot display, pico-projector, or liquid crystal on silicon (LCOS) display for directing image light to a wearer of HMD500.

The frame514and arms511of the HMD500may include supporting hardware of HMD500. HMD500may include any of processing logic551, wired and/or wireless data interface for sending and receiving data, graphic processors, and one or more memories for storing data and computer-executable instructions. In one embodiment, HMD500may be configured to receive wired power. In one embodiment, HMD500is configured to be powered by one or more batteries. In one embodiment, HMD500may be configured to receive wired data including video data via a wired communication channel. In one embodiment, HMD500is configured to receive wireless data including video data via a wireless communication channel.

Lenses521may appear transparent to a user to facilitate augmented reality or mixed reality where a user can view scene light from the environment around her while also receiving image light directed to her eye(s) by waveguide(s)550. Consequently, lenses521may be considered (or include) an optical combiner. In some embodiments, image light is only directed into one eye of the wearer of HMD500. In an embodiment, both displays530A and530B are included to direct image light into waveguides550A and550B, respectively.

The example HMD500ofFIG.5includes an array of infrared emitters (e.g. infrared LEDs)560disposed around a periphery of lens521B in frame514. The infrared emitters emit light in an eyeward direction to illuminate an eye of a wearer of HMD500with infrared light. In one embodiment, the infrared light is centered around 850 nm. Infrared light from other sources may illuminate the eye as well. The infrared light may reflect off the eye and be received by a Fresnel reflector599selectively coated with a hot mirror and configured to direct and focus the reflected infrared light to camera547. Fresnel reflector599may have an off-axis Fresnel lensing shape to direct the reflected infrared light to camera547. In this way, camera547is able to image the eye of a wearer of HMID500. Camera547may be mounted on the inside of the temple of HMD500. The images of the eye captured by camera547may be used for eye-tracking purposes. Although camera547, infrared emitters560, and Fresnel reflector599are illustrated on only one side of HMD500, they of course may be duplicated on the other side of HMD500to facilitate infrared imaging of both eyes of a wearer of HMD500.

Camera module509may be outward facing to support HMD500operations. For example, camera module509may be used to provide pass-through imaging that enables a user to temporarily see the surrounding environment prior to, for example, engaging in fully immersive VR experiences. Camera module509may be outward facing to support artificial intelligence (AI) identification of one or more people, places, landmarks, and/or objects in an environment, according to an embodiment. Camera547and camera module509may be example implementations of the embodiments of camera modules disclosed throughout the present disclosure.

The term “processing logic” in this disclosure may include one or more processors, microprocessors, multi-core processors, Application-specific integrated circuits (ASIC), and/or Field Programmable Gate Arrays (FPGAs) to execute operations disclosed herein. In some embodiments, memories (not illustrated) are integrated into the processing logic to store instructions to execute operations and/or store data. Processing logic may also include analog or digital circuitry to perform the operations in accordance with embodiments of the disclosure.

A “memory” or “memories” described in this disclosure may include one or more volatile or non-volatile memory architectures. The “memory” or “memories” may be removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. Example memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile disks (DVD), high-definition multimedia/data storage disks, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by a computing device.

Communication channels may include or be routed through one or more wired or wireless communication utilizing IEEE 802.11 protocols, BlueTooth, SPI (Serial Peripheral Interface), I2C (Inter-Integrated Circuit), USB (Universal Serial Port), CAN (Controller Area Network), cellular data protocols (e.g. 3G, 4G, LTE, 5G), optical communication networks, Internet Service Providers (ISPs), a peer-to-peer network, a Local Area Network (LAN), a Wide Area Network (WAN), a public network (e.g. “the Internet”), a private network, a satellite network, or otherwise.

A computing device may include a desktop computer, a laptop computer, a tablet, a phablet, a smartphone, a feature phone, a server computer, or otherwise. A server computer may be located remotely in a data center or be stored locally.