Die metallization for densely packaged arrays

Abstract

A lighting device is provided in which a plurality of light emitting diode (LED) dies are connected in series by an intermediate metallization layer. The cathode under bump metallization (nUBM) has an L shape, and the anode UBM (pUBM) has a rectangle. The combined nUBM and pUBM shapes are square and arranged to maintain a constant distance therebetween. The L-shaped leg of the nUBM of one die is connected to a metallization layer, which is connected to the pUBM of an adjacent die. The metallization layer maintains a constant distance from the pUBM of the one die. A connection between the metallization layer and the nUBM is positioned to the one die.

Description

[0001] Priority claim This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 433,095, filed December 16, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to die and tile metallization. In particular, embodiments are directed to die and tile metallization in dense light emitting diode (LED) structures. Background Art

[0003] Efforts are currently underway to improve multi-die lamp architectures. In particular, it is desirable to improve die thermal resistance and the sharpness of brightness cutoff while maintaining brightness uniformity across the LED array in a multi-die lamp architecture. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 A lighting device according to some examples is shown.

[0005] Figure 2A A top view of a single die package architecture is shown, according to some examples.

[0006] Figure 2B Shown according to some examples Figure 2A Cross-sectional view of the single-die package architecture.

[0007] Figure 3A A top view of a single die package architecture is shown, according to some examples.

[0008] Figure 3B Shown according to some examples Figure 3A Cross-sectional view of the single-die package architecture.

[0009] Figure 4A A top view of a multi-die package architecture is shown, according to some examples.

[0010] Figure 4B Shown according to some examples Figure 4A Top view of the metallization of the multi-die package architecture.

[0011] Figure 4C Shown according to some examples Figure 4A Cross-sectional view of a multi-die package architecture.

[0012] Figure 5A A top view of a multi-die package architecture is shown, according to some examples.

[0013] Figure 5B Shown according to some examples Figure 5A Top view of the metallization of the multi-die package architecture.

[0014] Figure 5C Shown according to some examples Figure 5A Cross-sectional view of a multi-die package architecture.

[0015] Figure 6 An example of an electronic device in accordance with some embodiments is shown.

[0016] Figure 7 An example lighting system is shown in accordance with some embodiments.

[0017] Figure 8 An example hardware arrangement for implementing the above-disclosed subject matter is shown, according to some embodiments.

[0018] Figure 9 An example hardware arrangement for implementing the above-disclosed subject matter is shown, according to some embodiments.

[0019] Figure 10 An example method of fabricating an LED device according to some embodiments is shown. DETAILED DESCRIPTION

[0020] Die and tile metallization in dense LED structures and methods of manufacturing the LED structures are provided. The LED structures can be used in various applications such as flashes for camera applications, display applications, and automotive applications.

[0021] Figure 1 A lighting device 100 is shown according to some examples. Lighting device 100 may be, for example, a smartphone or a standalone camera that includes an adaptive LED light source. Lighting device 100 may include both a light source 110 and a camera 120. Regardless of whether scene 104 is illuminated by light source 110, camera 120 may capture an image of scene 104 during an exposure duration of camera 120. A processor 130 may be used to control various functions of light source 110 and camera 120, including whether a shutter in opening 108 of a housing of lighting device 100 is open.

[0022] The opening 108 may be Figure 1 Similarly, the shutter may be a single shutter covering both the light source 110 and the camera 120, or may include multiple separate shutters that cover only one of the light source 110 or the camera 120 and that can be individually controlled by the processor 130.

[0023] The lighting device 100 may include one or more LED arrays 112. Each of the one or more LED arrays 112 may include a plurality of LEDs 114 that can generate light during at least a portion of an exposure duration of the camera 120. Each of the one or more LED arrays 112 may include segmented LEDs 114, where the LEDs 114 are divided into a grid of light-emitting regions (LEDs 114) and non-light-emitting regions (between LEDs 114). In some embodiments, the effect of the non-light-emitting regions on an image captured using the one or more LED arrays 112 can be compensated for by moving the one or more LED arrays 112 and / or at least one lens 116 during the exposure duration of the scene 104 using one or more actuators to slightly move the LEDs 114 to illuminate areas of the scene 104 that would be affected by the non-light-emitting regions.

[0024] Each LED 114 can be formed using one or more inorganic semiconductor materials (e.g., binary compounds such as gallium arsenide (GaAs) or gallium nitride (GaN), ternary compounds such as aluminum gallium arsenide (AlGaAs), or quaternary compounds such as indium gallium arsenide phosphide (InGaAsP)), or other suitable materials. LEDs 114 are typically Group III-V materials (defined by the columns of the periodic table) or Group II-VI materials. Each LED 114 can emit light in the visible spectrum (approximately 400 nm to approximately 780 nm) or in the infrared spectrum (above approximately 780 nm). In some embodiments, one or more additional layers (such as a phosphor layer) can be provided over each of the one or more LED arrays 112 to convert the light from the LEDs 114 into white light (or light of another color). In a particular LED array 112, LEDs 114 emitting light in the infrared spectrum can be interspersed with LEDs 114 emitting light in the visible spectrum, for example, or each type of LED (visible light emitter / infrared emitter) can be provided in different portions of a particular LED array 112. Alternatively, each LED array 112 may emit light only in the visible spectrum or the infrared spectrum; separate LED array(s) may be used to emit light in the infrared spectrum, and each of the separate LED arrays 112 , LEDs 114 , and / or LED segments may be controlled by the processor 130 .

[0025] Each of the one or more LED arrays 112 can be, for example, a micro-LED array, which includes thousands to millions of micro-LEDs 114 that can emit light and can be controlled individually or in groups of pixels (e.g., 5×5 pixel groups). Compared to typical LEDs, micro-LEDs are relatively small (e.g., side length <0.01 mm) and can use inorganic semiconductor materials (such as those indicated above) to provide monochromatic or multi-color light, typically red, green, or blue.

[0026] Light source 110 may include at least one lens 116 and / or other optical elements (such as a reflector) that may direct light emitted by one or more LED arrays 112 toward scene 104 as illumination 102 .

[0027] Camera 120 can sense at least one or more wavelengths of light emitted by one or more LED arrays 112. Similar to light source 110, camera 120 can include optics (e.g., at least one camera lens 122) capable of collecting light 106 reflected from scene 104 and / or reflected from illumination 102 emitted by scene 104. Camera lens 122 can direct reflected light 106 onto a multi-pixel sensor 124 (also referred to as a light sensor) to form an image of scene 104 on multi-pixel sensor 124.

[0028] The processor 130 may receive a data signal representing an image of the scene 104. The processor 130 may additionally control and drive the LEDs 114 in the one or more LED arrays 112 via one or more drivers 132. For example, the processor 130 may optionally control one or more LEDs 114 in the one or more LED arrays 112 independently of one or more LEDs 114 in the one or more LED arrays 112 to illuminate the scene in a specified manner.

[0029] Furthermore, one or more detectors 126 may be incorporated into camera 120. In other embodiments, one or more detectors 126 may be incorporated into one or more different areas, such as light source 110 or elsewhere near camera 120, rather than being incorporated into camera 120. One or more detectors 126 may include multiple different sensors to sense visible light and / or infrared light (e.g., from scene 104) and, in addition to receiving reflected light from LED 114, further sense ambient light and / or changes / flickering in ambient light. The multi-pixel sensor 124 of camera 120 may have a higher resolution than the sensors of one or more detectors 126 to obtain an image of the scene with a desired resolution. Similar to LED array 112, the sensors of one or more detectors 126 may have one or more segments (capable of sensing the same wavelength / wavelength range or different wavelengths / wavelength ranges). In some embodiments, if multiple detectors are used, one or more detectors may detect visible light wavelengths and one or more detectors may detect infrared wavelengths. Like one or more LED arrays 112, one or more detectors 126 may be individually controllable by processor 130.

[0030] In some embodiments, instead of being provided in the camera 120 or in addition to being provided in the camera 120, one or more sensors of the one or more detectors 126 can be provided in the light source 110. In some embodiments, the light source 110 and the camera 120 can be integrated into a single module, while in other embodiments, the light source 110 and the camera 120 can be separate modules provided on a PCB. In other embodiments, the light source 110 and the camera 120 can be attached to different PCBs - for example, because the camera 120 can be thicker than the light source 110, which can cause design problems if the light source 110 and the camera 120 are attached to the same PCB. In the latter embodiment, there can be multiple openings in the housing, at least one of which can be eliminated by using an integrated light source 110 and camera 120.

[0031] LEDs 114 can be driven using either a direct current (DC) driver or pulse-width modulation (PWM). If segmented LED arrays 112 are driven at different current densities, DC drive may result in color shading, while PWM drive may generate artifacts due to ambient lighting conditions. If a flicker sensor is present, it can sense changes in artificial lighting at the wall current frequency or electronic ballast frequency (e.g., 50 Hz or 60 Hz, or integer multiples thereof) in addition to the phase of the flicker. The camera sensor is then tuned to an integration time that is an integer multiple of the time period (1 / f) or is triggered at the phase where the lighting changes most slowly (either minimum or maximum intensity, with maximum intensity being preferred for signal-to-noise ratio considerations). PWM can be used to drive LEDs 114, with the phase shift varying between LEDs 114 to reduce potential current surge issues. As shown, one or more drivers 132 can be used to drive the LEDs 114 in one or more LED arrays 112, as well as other components such as actuators.

[0032] The lighting device 100 may also include an input device 134, for example a user-activated input device such as a button that is pressed to take a picture. The light source 110 and the camera 120 may be provided in a single housing.

[0033] LEDs can be used for Figure 1 The lighting device 100 shown in FIG. 1 can be used to form various types of displays, LED matrices, and light engines, including adaptive automotive headlights, augmented reality (AR), virtual reality (VR), or mixed reality (MR) headsets, smart glasses, and displays for mobile phones, smartwatches, monitors, and TVs. Depending on the size of the matrix or display and the pixel-per-inch requirements, the individual LED pixels in these architectures can have an area ranging from a few square millimeters to several square microns.

[0034] It may be desirable to improve the overall system optical efficiency for each different type of application. In particular, the optical efficiency of multi-die package applications that provide illumination for sustained periods of time may be relatively low unless carefully designed. Figure 2A A top view of a single die package architecture is shown, according to some examples. Figure 2B Shown according to some examples Figure 2A For clarity, Figure 2A and Figure 2BThe package architecture 200 shown in FIG. shows only a single LED die 210. LED die 210 may include a semiconductor stack 206, which may be fabricated by combining n-type and p-type semiconductors (e.g., the aforementioned III-V semiconductors) on a substrate (wafer), such as sapphire or silicon carbide (SiC). During LED fabrication, various layers may be deposited and processed on the substrate. Prior to depositing the various layers, the substrate surface may be pre-treated to include annealing, etching, polishing, and the like.

[0035] Generally speaking, the various layers of an LED can be fabricated using epitaxial semiconductor deposition (e.g., metal-organic chemical vapor deposition) to deposit one or more semiconductor layers, metal deposition (e.g., by sputtering, plating, or evaporation), oxide growth, and other operations such as etching, stripping, and cleaning. Semiconductor deposition can be used to create an LED with an active region where electron-hole recombination occurs and light from the LED is generated. The active region can be, for example, one or more quantum wells. Metal contacts can be used to provide drive current to the n-type and p-type semiconductors from an integrated circuit (IC) (such as a driver) on the backplane on which the LED is mounted.

[0036] End contacts 208 and center contacts 212 can be fabricated to make electrical contact with different layers of semiconductor stack 206. The LED anode can be electrically coupled to anode under-bump metallization (UBM) (pUBM) 204, and the cathode can be electrically coupled to cathode UBM (nUBM) 202. Note that in different embodiments, the positions of nUBM 202 and pUBM 204 can be interchanged. nUBM 202 and pUBM 204 can be patterned and formed of a metal, such as, for example, copper (Cu), nickel (Ni), gold (Au), silver (Ag), and / or titanium (Ti), which can be deposited on LED die 210.

[0037] like Figure 2B As shown in FIG, the pUBM 204 and nUBM 202 can be electrically connected to a patterned tile metallization layer 214 disposed on a tile 222 (also referred to as a substrate). The electrical connection can be formed by direct contact (e.g., thermocompression bonding) or by a soldering and reflow process, whereby the solder wets the two metal interfaces and forms a strong joint upon cooling. The tile metallization layer 214 can be formed of a metal (such as Cu), which can be the same as or different from the material(s) used to form the nUBM 202 and pUBM 204. The tile metallization layer 214 can completely cover the pUBM 204 and nUBM 202 to ensure electrical contact between them.

[0038] Tiles 222 can be made of, for example, FR4, ceramic, or aluminum nitride (AlN). They can be placed on a thermal interface material (TIM) / electrode layer 224, which can include a metal (such as those mentioned above) and, for example, thermal epoxy or grease. The TIM / electrode layer 224 can serve as an electrode layer connecting the tiles 222 to a heat sink 226, for example, formed of Al.

[0039] like Figure 2A and Figure 2B As shown in FIG, nUBMs 202 and pUBMs 204 are positioned on adjacent sides of LED die 210, alternating from left to right along the linear array of LED die 210. With this die orientation, significant current may flow into the gap between nUBMs 202 and pUBMs 204, generating heat in this gap. This may cause heat generated in LED die 210 to radiate laterally along LED die 210 before being transferred to heat sink 226. However, the lateral conduction distance (e.g., several hundred μm) may be one or more orders of magnitude greater than the vertical conduction distance (e.g., several μm). That is, for heat to flow out of LED die 210 and into the submount, the heat may travel laterally a considerable distance (e.g., greater than approximately 100 μm) through a relatively thin metal sheet (e.g., approximately 1 μm thick x approximately 1000 μm) to reach nUBMs 202 and pUBMs 204. Heat generated in such an area can be considered to experience high thermal resistance and may result in excessive heat generation in a localized region, thereby reducing optical efficiency.

[0040] To improve the optical efficiency of, for example, low-beam and high-beam lamps (in which one or more LED light sources are present), the brightness of the LED light source can be concentrated in one area (e.g., along the top edge of the LED package). Figure 2A The layout can rotate the die orientation so that the nUBM and pUBM areas of the die are located at the top of the array, where the brightness and current density are highest in this application. Figure 3A A top view of a single die package architecture is shown, according to some examples. Figure 3B Shown according to some examples Figure 3A As mentioned above, for the sake of clarity, Figure 3A and Figure 3BThe package architecture 300 shown in FIG shows only a single LED die 310. The LED die 310 can include a semiconductor stack 306. End contacts 308 and center contacts 312 can be fabricated to electrically contact different layers of the semiconductor stack 306. The nUBM 302 and pUBM 304 can be electrically connected to a patterned tile metallization layer 314 disposed on a tile 322. The tile metallization layer 314 can completely cover the pUBM 304 and nUBM 302 to ensure electrical contact therebetween. The tile 322 can be disposed on a TIM 324 that connects the tile 322 to a heat sink 326. Figure 3A and Figure 3B The materials of each layer in can be similar to Figure 2A and Figure 2B As shown, the brightness of the LED die 310 can be concentrated along the top edge of the LED die 310, which is electrically contacted by the nUBM 302. In various embodiments, the positions of the nUBM 302 and the pUBM 304 can be swapped.

[0041] Although Figure 3A and Figure 3B The configuration shown in may allow the anode (or cathode) to be aligned to improve heat conduction away from the area of ​​the LED where the most heat is generated, but Figure 3A and Figure 3B The package architecture 300 shown in FIG. 3 may present other challenges. In particular, the die layout in a multi-die package architecture may be configured such that the LED dies are electrically arranged in series. Figure 4A A top view of a multi-die package architecture according to some examples is shown. In the package architecture 400 , LED dies 410a , 410b are adjacent and relatively close together (eg, separated by only a few microns) to increase the brightness of the package architecture 400 . Figure 4B Shown according to some examples Figure 4A Top view of the metallization of the multi-die package architecture. Figure 4C Shown according to some examples Figure 4A A cross-sectional view of the multi-die package architecture. Figure 4B As can be seen in FIG, each of the LED dies 410a, 410b in the package architecture 400 is associated with a different nUBM 402a, 402b and pUBM 404a, 404b. Each of the nUBMs 402a, 402b and pUBMs 404a, 404b is electrically coupled to a patterned tile metallization layer 414a, 414b that overlaps the associated nUBM 402a, 402b and pUBM 404a, 404b. As described above, the positions of the nUBMs 402a, 402b and pUBMs 404a, 404b of each LED die 410a, 410b can be interchanged.

[0042] exist Figure 4B and Figure 4C In the rotated configuration shown in , the spacing between the LED dies 410a, 410b may be limited by the substrate trace width and the spacing between traces in the metallization layers 414a, 414b on top of the tile 416, and may not be able to be spaced as closely together as in prior art configurations without risking electrical shorting along the diagonal trace 414c that connects the tile metallization layer 414a associated with the pUBM 404a of one LED die 410a and the tile metallization layer 414b associated with the nUBM 402b of the adjacent LED die 410b. As can be seen, Figure 4A and Figure 4B The arrangement in FIG. 4 may result in a tradeoff between improved thermal performance and acceptable brightness uniformity for the multi-die array along the package architecture 400. Because the LED dies 410a, 410b may not be able to be placed so closely together, the brightness along the package architecture 400 may decrease between the LED dies 410a, 410b and, therefore, may be undesirable.

[0043] The tradeoff can be mitigated by co-designing the UBM (both nUBM and pUBM) and tile metallization so that current density and heat generation are highest above the die area with the lowest thermal resistance, highest brightness at the top of the package for best contrast, and maintaining minimized die spacing without compromising uniformity of inter-die contrast. The UBM and tile layout can be modified to allow the dies to be spaced apart at the same spacing as the configuration of the above figures.

[0044] In the package architecture 500 , the LED dies 510 a , 510 b are adjacent and relatively close together (eg, separated by only a few microns) to increase the light output of the package architecture 500 . Figure 5B Shown according to some examples Figure 5A Top view of the metallization of the multi-die package architecture. Figure 5C Shown according to some examples Figure 5A A cross-sectional view of the multi-die package architecture. Figure 5BAs can be seen in FIG, each of the LED dies 510a, 510b in the package architecture 500 is associated with a different nUBM 502a, 502b and pUBM 504a, 504b. Each of the nUBMs 502a, 502b and pUBMs 504a, 504b is electrically coupled to a patterned tile metallization layer 514a, 514b that overlaps the associated nUBM 502a, 502b and pUBM 504a, 504b. As described above, the positions of the nUBMs 502a, 502b and pUBMs 504a, 504b of each LED die 510a, 510b can be interchanged. Tile metallization layers 514a, 514b can be provided on tile 516, on which TIM 518 is used to connect tile 516 to heat sink 520, which dissipates heat from LED dies 510a, 510b. In some embodiments, solder paste can be used at any electrical interface, such as between nUBM 502a, 502b / pUBM 504a, 504b and tile metallization layers 514a, 514b.

[0045] exist Figure 5B and Figure 5C In the configuration shown in , the spacing between the LED dies 510a, 510b is no longer limited by the substrate trace width and the spacing between traces in the metallization layers 514a, 514b on top of the tile 516 because there are no diagonal traces used to connect the tile metallization layer 514a associated with the pUBM 504a of one LED die 510a to the tile metallization layer 514b associated with the nUBM 502b of the adjacent LED die 510b. Instead, as shown in FIG. Figures 5A-5C As shown in FIG, one of the UBMs (nUBM 502a, 502b or pUBM 504a, 504b) can be formed into a substantially L-shape (within manufacturing tolerances). That is, as shown, at least one of the nUBM 502a, 502b or pUBM 504a, 504b can have a relatively large (rectangular) area 502aa, 502ba and a relatively small (rectangular) area 502ab, 502bb that extends at or near one end of the larger area 502aa, 502ba in a direction substantially perpendicular to the larger area 502aa, 502ba. This can move the gap between the tile metallization 514a, 514b below the LED dies 510a, 510b, rather than between the LED dies 510a, 510b. Furthermore, the tile metallization 514a, 514b connector 514c may extend in a direction perpendicular to the separation d between the LED dies 510a, 510b, rather than extending diagonally, as in Figure 4B-4CIn other embodiments, shapes other than an L-shape may be used.

[0046] The package architecture 500 can separate the minimum inter-die spacing from the tile metallization trace gap and width tolerances. As shown, the lateral distance between the tile metallizations in adjacent LED dies 510b can remain substantially constant, and the lateral distance between the nUBMs 502b and pUBMs 504b in adjacent LED dies 510b can also remain substantially constant. Furthermore, the areas of the nUBMs 502a, 502b and pUBMs 504a, 504b can remain substantially the same as in other embodiments described herein. Although Figures 5A-5C The overall shape of the nUBM 502a, 502b or pUBM 504a, 504b within each LED die 510a, 510b forms substantially a square (or rectangle), although other overall shapes may result depending on the individual shapes of the nUBM 502a, 502b or pUBM 504a, 504b.

[0047] Note that in Figures 5A-5C Only two LED dies are shown in FIG. However, any number of LED dies connected in series may be used. For example, in automotive applications, up to six LED dies connected in series may be used for low beam lighting. Thus, Figures 5A-5C arrangement.

[0048] While the UBM dimensions are shown as being substantially the same in the above embodiments, in other embodiments, the UBM dimensions may vary depending on the application. For example, a surface brightness map or thermal map may be used to determine the size of the UBM. In some embodiments, the UBM may be sized to cover an area of ​​the LED die where the brightness is greater than approximately 60% of the LED die's maximum brightness, greater than approximately 75% of the LED die's maximum brightness, or at least less than an area between approximately 60% and approximately 80% of the LED die's maximum brightness. Alternatively, the smaller solder pad (UBM) may be approximately 150 μm, approximately 100 μm, approximately 50 μm, or even approximately 25 μm, while the gap between the UBM and the LED die may be approximately 200 μm, approximately 100 μm, or approximately 25 μm. This may allow for other shapes for the UBM.

[0049] Figure 6An example of an electronic device according to some embodiments is shown. Electronic device 600 may be: a mobile device such as a laptop computer (PC), tablet PC, or smartphone, for example, an automotive device; or a dedicated electronic device such as a camera. Various components may be provided on the aforementioned PCB. As described herein, examples may include logic or a number of components, modules, or mechanisms, or may operate across a number of components, modules, or mechanisms. Modules and components are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In one example, circuits may be arranged in a specified manner as modules (e.g., internally or relative to external entities such as other circuits). In one example, all or part of one or more computer systems (e.g., standalone, client, or server computer systems) or one or more hardware processors may be configured as modules to perform specified operations using firmware or software (e.g., instructions, application components, or applications). In one example, the software may reside on a machine-readable medium. In one example, when executed by the module's underlying hardware, the software causes the hardware to perform the specified operations.

[0050] Therefore, the term "module" (and "component") should be understood to encompass a tangible entity, i.e., a physically constructed, specially configured (e.g., hardwired), or temporarily (e.g., temporarily) configured (e.g., programmed) entity that operates in a specified manner or performs some or all of any of the operations described herein. Considering examples where modules are temporarily configured, each module need not be instantiated at any one time. For example, where a module comprises a general-purpose hardware processor configured using software, the general-purpose hardware processor can be configured as corresponding different modules at different times. The software can accordingly configure the hardware processor, for example, to configure a particular module at one time and to configure different modules at different times.

[0051] Mobile device 600 may include a hardware processor (or equivalent processing circuitry) 602 (e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), main memory 604, and static memory 606, some or all of which may communicate with each other via an interconnect (e.g., a bus) 608. Main memory 604 may include any or all of removable and non-removable storage, volatile memory, or non-volatile memory. Mobile device 600 may also include a display 610 (such as a video display), an alphanumeric input device 612 (e.g., a keyboard), and a user interface (UI) navigation device 614 (e.g., a mouse). In one example, display 610, input device 612, and UI navigation device 614 may be touchscreen displays. Mobile device 600 may additionally include a storage device (e.g., a drive unit) 616, a signal generating device 618 (e.g., a speaker), a network interface device 620, one or more cameras 628, and one or more sensors 630 (such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensors such as those described herein). The mobile device 600 may also include an output controller, such as a serial connection (e.g., Universal Serial Bus (USB)), a parallel connection, or other wired or wireless connection (e.g., infrared (IR), near field communication (NFC), etc.) to communicate with or control one or more peripheral devices (e.g., a printer, a card reader, etc.).

[0052] Storage device 616 may include a non-transitory machine-readable medium 622 (hereinafter referred to as a machine-readable medium) on which one or more sets of data structures or instructions 624 (e.g., software) are stored. These sets of data structures or instructions 624 embody or are used by any one or more of the techniques or functionality described herein. Non-transitory machine-readable medium 622 is a tangible medium. The inclusion of a non-transitory machine-readable medium in storage device 616 should not be interpreted as meaning that the device or machine-readable medium itself cannot be physically moved. During execution of its instructions 624 by mobile device 600, the instructions 624 may also reside, completely or at least partially, within main memory 604, within static memory 606, and / or within hardware processor 602. While machine-readable medium 622 is illustrated as a single medium, the term "machine-readable medium" may encompass a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store one or more instructions 624.

[0053] The term "machine-readable medium" may include any medium capable of storing, encoding, or carrying instructions for execution by the mobile device 600 and causing the mobile device 600 to perform any one or more of the techniques disclosed herein; or any medium capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting examples of machine-readable media may include solid-state memory, as well as optical and magnetic media. Specific examples of machine-readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; random access memory (RAM); and CD-ROM and DVD-ROM disks.

[0054] The instructions 624 may also be transmitted or received via the network interface device 620 using a transmission medium 626 over a communication network using any of a number of wireless local area network (WLAN) transmission protocols (e.g., frame relay, Internet Protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), a mobile phone network (e.g., a cellular network), a plain old telephone (POTS) network, and a wireless data network. Communications over the network may include one or more different protocols, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi, the IEEE 802.16 family of standards known as WiMax, the IEEE 802.15.4 family of standards, the Long Term Evolution (LTE) family of standards, the Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, next generation (NG) / fifth generation (5G) standards, and the like. In one example, the network interface device 620 may include one or more physical jacks (eg, Ethernet jacks, coaxial jacks, or telephone jacks) or one or more antennas to connect to the transmission medium 626 .

[0055] Note that the term "circuit," as used herein, refers to, is part of, or includes a hardware component, such as an electronic circuit, a logic circuit, a processor (shared, dedicated, or grouped) and / or memory (shared, dedicated, or grouped), an application-specific integrated circuit (ASIC), a field-programmable device (FPD) (e.g., a field-programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high-capacity PLD (HCPLD), a structured ASIC, or a programmable SoC), a digital signal processor (DSP), or the like, that is configured to provide the described functionality. In some embodiments, the circuit may execute one or more software or firmware programs to provide at least some of the described functionality. The term "circuit" may also refer to a combination of one or more hardware elements (or a combination of circuits used in an electrical or electronic system) and program code for performing the functions of the program code. In these embodiments, the combination of hardware elements and program code may be referred to as a specific type of circuit.

[0056] As used herein, the term "processor circuit" or "processor" therefore refers to, is part of, or includes a circuit that is capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, and / or transmitting digital data. The term "processor circuit" or "processor" may refer to one or more application processors, one or more baseband processors, a physical central processing unit (CPU), a single-core or multi-core processor, and / or any other device capable of executing or otherwise operating computer-executable instructions (such as program code, software modules, and / or functional processes).

[0057] Figure 7 700. As described above, some of the elements shown in lighting system 700 may not be present, while other additional elements may be provided in lighting system 700. Lighting system 700 may be based on Figure 1 The lighting system 700 may provide illumination based on the captured image described in , or may independently generate illumination based on stored information. For example, the lighting system 700 may include a controller 702 that controls the display of an image using a pixel array 710 comprising a plurality of individual pixels 712 .

[0058] In some embodiments, some or all of the components described as controller 702 may be provided on a backplane (such as, for example, a composite metal oxide semiconductor (CMOS) backplane). Controller 702 may be coupled to or include one or more processors 704. Controller 702 may receive image data and queries from one or more processors 704 (if external to controller 702). In this case, controller 702 may further provide feedback to one or more processors 704. One or more processors 704 may receive image data via a digital interface and may process the image data to control PWM generator 706a, for example, to control the PWM duty cycle and / or on-time, so that lighting system 700 produces an image indicated by the image data.

[0059] The controller 702 may further include a frame buffer 708. The frame buffer 708 may store one or more images before the one or more processors 704 and store instructions for implementation by the one or more processors 704.

[0060] The PWM generator 706a can be controlled by one or more processors 704 and can generate a PWM signal according to instructions. The PWM generator 706a can be connected to the driver 706b to drive the pixel array 710 so that the pixels 712 provide a desired light intensity.

[0061] Each pixel 712 can include one or more LEDs 714. The LEDs 714 can be of different colors and can be controlled individually or in groups. As shown, for each pixel 712 or LED 714, the pixel 712 can include a PWM switch and a current source. The pixel 712 can be driven by a driver 706b. The PWM signal from the PWM generator 706a can cause the PWM switch to open and close according to the value of the PWM signal. The signal corresponding to the light intensity can cause the current source to generate a current, thereby causing the pixel 712 to produce the corresponding light intensity.

[0062] The lighting system 700 can further include a power supply 720. In some embodiments, the power supply 720 can generate power for the controller 702.

[0063] Figure 8A block diagram illustrates an example of a system according to some embodiments. System 800 can use LEDs to provide augmented reality (AR) / virtual reality (VR) functionality. System 800 can include a wearable housing 812, such as a headset or goggles. Housing 812 can mechanically support and house the components described in detail below. In some examples, one or more of the components described in detail below can be included in one or more additional housings that can be separate from wearable housing 812 and can be coupled to wearable housing 812 wirelessly and / or via a wired connection. For example, a separate housing can reduce the weight of wearable goggles, such as by including batteries, radios, and other components. Housing 812 can include one or more batteries 814 that can power any or all of the components described in detail below. Housing 812 can include circuitry that can be electrically coupled to an external power source (such as a wall outlet) to charge batteries 814. Housing 812 can also include one or more radios 816 for wireless communication with a server or network via a suitable protocol (such as WiFi).

[0064] The system 800 may include one or more sensors 818, such as optical sensors, audio sensors, tactile sensors, thermal sensors, gyroscope sensors, time-of-flight sensors, triangulation-based sensors, and the like. In some examples, one or more of these sensors may sense the location, position, and / or orientation of the user. In some examples, one or more sensors 818 may generate sensor signals in response to the sensed location, position, and / or orientation. The sensor signals may include sensor data corresponding to the sensed location, position, and / or orientation. For example, the sensor data may include a depth map of the surrounding environment. In some examples, such as for an AR system, one or more sensors 818 may capture real-time video images of the surrounding environment near the user.

[0065] System 800 may include one or more video generation processors 820. The one or more video generation processors 820 may receive scene data representing a three-dimensional scene, such as a set of position coordinates of objects in the scene or a depth map of the scene. This data may be received from a server and / or a storage medium. The one or more video generation processors 820 may receive one or more sensor signals from one or more sensors 818. In response to the scene data representing the surrounding environment and at least one sensor signal representing the location and / or orientation of a user relative to the surrounding environment, the one or more video generation processors 820 may generate at least one video signal corresponding to a view of the scene. In some examples, the one or more video generation processors 820 may generate two video signals, one for each eye of the user, the two video signals representing views of the scene from the perspective of the user's left eye and right eye, respectively. In some examples, the one or more video generation processors 820 may generate more than two video signals and combine the video signals to provide one video signal for both eyes, two video signals for both eyes, or other combinations.

[0066] The system 800 may include one or more light sources 822 that can provide light for the display of the system 800. For example, suitable light sources 822 may include the LEDs described above. The one or more light sources 822 may include light emitting elements having different colors or wavelengths. For example, the light sources may include a red light emitting diode that can emit red light, a green light emitting diode that can emit green light, and a blue light emitting diode that can emit blue light. The red, green, and blue light may be combined in a specific ratio to produce any suitable color that is visually perceptible in the visible portion of the electromagnetic spectrum.

[0067] The system 800 may include one or more modulators 824. The modulator 824 may be implemented in one of at least two configurations. In a first configuration, the modulator 824 may include a circuit that can directly modulate the light source 822. For example, the light source 822 may include an array of light-emitting diodes, and the modulator 824 may directly modulate the electrical power, voltage, and / or current directed to each light-emitting diode in the array to form modulated light. The modulation may be performed in an analog manner and / or digitally. In some examples, the light source 822 may include an array of red light-emitting diodes, an array of green light-emitting diodes, and an array of blue light-emitting diodes, and the modulator 824 may directly modulate the red light-emitting diodes, the green light-emitting diodes, and the blue light-emitting diodes to form modulated light to produce a particular image.

[0068] In a second configuration, the modulator 824 may include a modulation panel, such as a liquid crystal panel. The light source 822 may generate uniform or nearly uniform illumination to illuminate the modulation panel. The modulation panel may include pixels. Each pixel may selectively attenuate a corresponding portion of the modulation panel area in response to an electrical modulation signal to form modulated light. In some examples, the modulator 824 may include multiple modulation panels capable of modulating light of different colors. For example, the modulator 824 may include a red modulation panel capable of attenuating red light from a red light source (such as a red light-emitting diode), a green modulation panel capable of attenuating green light from a green light source (such as a green light-emitting diode), and a blue modulation panel capable of attenuating blue light from a blue light source (such as a blue light-emitting diode).

[0069] In some examples of the second configuration, the modulator 824 can receive uniform white light, or nearly uniform white light, from a white light source, such as a white light emitting diode. The modulation panel can include a wavelength selective filter on each pixel of the modulation panel. The panel pixels can be arranged in groups, such as three or four groups, where each group can form a pixel of a color image. For example, each group can include a panel pixel with a red filter, a panel pixel with a green filter, and a panel pixel with a blue filter. Other suitable configurations can also be used.

[0070] The system 800 can include one or more modulation processors 826 that can receive a video signal (such as from one or more video generation processors 820) and, in response, can generate an electrical modulation signal. For configurations in which the modulator 824 directly modulates the light source 822, the electrical modulation signal can drive the light source 822. For configurations in which the modulator 824 includes a modulation panel, the electrical modulation signal can drive the modulation panel.

[0071] The system 800 may include one or more beam splitters 828 (and / or beam combiners) that can combine light beams of different colors to form a single polychromatic light beam. For configurations in which the light source 822 may include multiple light emitting diodes of different colors, the system 800 may include one or more wavelength-sensitive (e.g., dichroic) beam splitters 828 that can combine the different colors of light to form a single polychromatic light beam.

[0072] System 800 can direct modulated light toward an observer's eyes in one of at least two configurations. In a first configuration, system 800 can function as a projector and can include suitable projection optics 830 that can project the modulated light onto one or more screens 832. Screens 832 can be positioned at a suitable distance from the user's eyes. System 800 can optionally include one or more lenses 834 that can position a virtual image of screen 832 at a suitable distance from the eyes, such as a close-focus distance of 500 mm, 750 mm, or another suitable distance. In some examples, system 800 can include a single screen 832 so that the modulated light can be directed toward both eyes of the user. In some examples, system 800 can include two screens 832 so that the modulated light from each screen 832 can be directed toward a respective eye of the user. In some examples, system 800 can include more than two screens 832. In a second configuration, system 800 can direct the modulated light directly into one or both eyes of the observer. For example, projection optics 830 may form an image on the retina of one eye of a user, or on the retina of each of both eyes of a user.

[0073] For some configurations of the AR system, system 800 may include a display that is at least partially transparent so that the user can view the user's surroundings through the display. For such configurations, the AR system can generate modulated light corresponding to an enhancement of the surrounding environment rather than the surrounding environment itself. For example, in the example of a retailer displaying chairs, the AR system can direct modulated light corresponding to the chairs rather than the rest of the room toward the screen or toward the user's eyes.

[0074] Figure 9 An example hardware arrangement for implementing the disclosed subject matter described above is shown, according to some embodiments. Specifically, hardware arrangement 900 can include an integrated LED 908. Integrated LED 908 can include an LED die 902, which includes an LED array(s) and a backplane, such as a CMOS backplane 904. LED die 902 can be coupled to CMOS backplane 904 via one or more interconnects 910, which can provide signal transmission between LED die 902 and CMOS backplane 904. Interconnect 910 can include one or more solder bump joints, one or more copper pillar bump joints, other types of interconnects known in the art, or some combination thereof.

[0075] In some embodiments, the LED die 902 may further include a switch and a current source to drive the micro LED array. In other embodiments, the PWM switch and current source may be included in the CMOS backplane 904.

[0076] The CMOS backplane 904 may include circuitry for implementing a control module and / or an LED power supply. The CMOS backplane 904 may utilize interconnects 910 to provide a PWM signal and an intensity signal to the micro-LED array, causing the micro-LED array to generate light in accordance with the PWM signal and intensity. Because the number and density of connections required to drive a micro-LED array are relatively large compared to a standard LED array, different embodiments may be used to electrically connect the CMOS backplane 904 and the LED die 902. Alternatively, the bonding pads of the CMOS backplane 904 may be spaced the same as the bonding pads of the micro-LED array, or the bonding pads of the CMOS backplane 904 may be spaced greater than the bonding pads of the micro-LED array.

[0077] Hardware arrangement 900 may further include a PCB 906. PCB 906 may include circuitry for implementing the various functions described herein. PCB 906 may be coupled to CMOS backplane 904. For example, PCB 906 may be coupled to CMOS backplane 904 via one or more wire bonds 912. PCB 906 and CMOS backplane 904 may exchange image data, power, and / or feedback, among other signals, via the coupling.

[0078] As shown, the microLEDs and the circuitry supporting the microLED array can be packaged and include a substrate or printed circuit board for powering the microLEDs and controlling the light produced by the microLEDs. The PCB supporting the microLED array can include electrical vias, a heat sink, a ground plane, electrical traces, and a flip chip or other mounting system. The substrate or PCB can be formed from any suitable material, such as ceramic, silicon, aluminum, etc. If the substrate material is conductive, an insulating layer can be formed over the substrate material, and a metal electrode pattern can be formed over the insulating layer to contact the microLED array. The substrate can act as a mechanical support, providing an electrical interface between the electrodes on the microLED array and the power supply, and also provide a heat sink function.

[0079] As described above, microLED arrays can support a variety of applications. These applications can include providing general illumination (for example, within a room or vehicle) or standalone applications that provide specialized images. In addition to devices such as lamps, projectors, and mobile devices, this system can also be used to provide applications based on augmented reality (AR) and virtual reality (VR). Visualization systems (such as VR and AR systems) are becoming increasingly common in a wide range of fields, including entertainment, education, medicine, and business. Various types of devices can be used to provide AR / VR to users, including headsets, glasses, and projectors. Such AR / VR systems may include components similar to those described above: a microLED array, a display or screen (which may include a touchscreen element), a microLED array controller, sensors, and a controller. The AR / VR components may be arranged in a single structure, or one or more of the components shown may be mounted separately and connected via wired or wireless communication. The controller can be provided with power and user data. User data input may include audio commands, haptic feedback, eye or pupil positioning, or information provided by a connected keyboard, mouse, or game controller. Sensors may include cameras, depth sensors, audio sensors, accelerometers, two-axis or three-axis gyroscopes, and other types of motion and / or environmental / wearer sensors that provide user input data. Other sensors may include, but are not limited to, air pressure, strain sensors, temperature sensors, or any other suitable sensor for local or remote environmental monitoring. In some embodiments, control inputs may include detected touches or taps, gesture inputs, or controls based on the position of the headset or display. As another example, an estimated position of the AR / VR system relative to an initial position may be determined based on one or more measurement signals from one or more gyroscopes or position sensors that measure translational or rotational movement.

[0080] In some embodiments, a controller can control individual microLEDs or one or more microLED pixels (microLED groups) to display content (AR / VR and / or non-AR / VR) to the user, while simultaneously controlling other microLEDs and sensors used in eye tracking to adjust the displayed content. The content-displaying microLEDs can be designed to emit light in the visible wavelength band (approximately 400 nm to 780 nm), while the microLEDs used for tracking can be designed to emit light in the IR band (approximately 780 nm to 2200 nm). In some embodiments, the tracking microLEDs and content microLEDs can be activated simultaneously. In some embodiments, the tracking microLEDs can be controlled to emit tracking light during periods when the content microLEDs are deactivated and therefore not displaying content to the user. The AR / VR system can incorporate optics (such as those described above) and / or an AR / VR display, for example, to couple light emitted by the microLED array to the AR / VR display.

[0081] In some embodiments, the AR / VR controller can use data from the sensor to time-integrate the measurement signal received from the accelerometer to estimate a velocity vector, and time-integrate the velocity vector to determine the estimated position of a reference point for the AR / VR system. In other embodiments, the reference point used to describe the position of the AR / VR system can be based on a depth sensor, a camera positioning view, or a light field flow. Based on changes in the position, orientation, or movement of the AR / VR system, the system controller can send an image or instruction to the light array controller. Changes or modifications to the image or instruction can also be made through user data input or automatic data input.

[0082] Generally speaking, in a VR system, a display can present a view of a scene (such as a three-dimensional scene) to a user. The user can move within the scene, such as by repositioning the user's head or by walking. The VR system can detect the user's movement and change the view of the scene to account for the movement. For example, when the user rotates the user's head, the system can present a view of the scene that changes in view direction to match the user's gaze. In this way, the VR system can simulate the user's presence in the three-dimensional scene. In addition, the VR system can receive tactile sensory input, such as from a wearable position sensor, and can optionally provide tactile feedback to the user.

[0083] On the other hand, in an AR system, the display can incorporate elements from the user's surroundings into the view of the scene. For example, an AR system can add text subtitles and / or visual elements to the view of the user's surroundings. For example, a retailer can use an AR system to show a user what a piece of furniture would look like in a room in the user's home by combining a visualization of the furniture on top of a captured image of the user's surroundings. As the user walks around the user's room, the visualization interprets the user's movements and changes the visualization of the furniture in a manner consistent with the movement. For example, an AR system can place a virtual chair in a room. The user can stand in front of the virtual chair's location in the room to view the front of the chair. The user can move to an area behind the virtual chair's location in the room to view the back of the chair. In this way, the AR system can add elements to the dynamic view of the user's surroundings.

[0084] Figure 10 An example method of manufacturing a lighting device according to some embodiments is shown. Not all operations may be performed in method 1000, and / or there may be additional operations. These operations may be performed in different ways. Figure 10 The order in which the sequence is indicated occurs.

[0085] At operation 1002, a semiconductor stack of an LED structure may be formed via an epitaxial process. The semiconductor stack includes n-type and p-type semiconductor layers, and an active region therebetween that generates light through electron-hole recombination. In some embodiments, fabrication of the semiconductor stack may include etching the n-type semiconductor layer to form fins. The semiconductor stack may be formed into any of several geometric shapes, such as a rectangle, to provide polarized light emission from one or more sidewalls of the semiconductor stack based on waveguides within the epitaxial semiconductor layers. The semiconductor stack may be formed on sapphire or other substrates.

[0086] After the semiconductor stack is fabricated, a UBM may be deposited in operation 1004. The UBM includes both nUBM and pUBM. At least one of the nUBM or the pUBM may be deposited in an L-like shape.

[0087] At operation 1006, the LED structure can be attached to a substrate. The substrate can be a PCB or other wafer that contains, for example, control and / or driver circuitry for controlling light emission from the LED structure. The substrate can include tile metallization that overlaps the nUBM and pUBM and connects the LED dies together in series by electrically connecting the nUBM of one of the LED dies to the pUBM of an adjacent LED die. The connection on the tile metallization between the nUBM of one of the LED dies and the pUBM of an adjacent LED die is disposed completely underneath (or only underneath) one of the LED dies. That is, the connection on the tile metallization between the nUBM of one of the LED dies and the pUBM of an adjacent LED die is positioned to one of the LED dies. The electrical and thermal interfaces between the LED UBM and the tile top metallization can be made by a direct contact process (e.g., via thermocompression bonding or another direct bonding method), or facilitated by a soldering and reflow process.

[0088] While the arrangement in some embodiments is designed for electrical series connection between the dies, in other embodiments, a parallel connection may be used. In a parallel connection, all anodes may be electrically connected together, and all cathodes may be electrically connected together.

[0089] Furthermore, while brightness cutoff is a feature of vehicle low beams, the multi-package LED arrays described herein can also be used in high beams where cutoff does not exist.

[0090] This embodiment can be applied to large-area LED dies that are not segmented, and therefore it is not possible to control the current flow in each pixel / segment of the die. Therefore, there are no sharp discontinuities in brightness between different areas of the die, but rather a smooth variation. In some embodiments, similar techniques can be applied to microLEDs comprising thousands to millions of microLEDs, which can emit light and can be controlled individually or in groups of pixels (e.g., 5×5 pixel groups). MicroLEDs are small (e.g., <0.01 mm on a side) and can use inorganic semiconductor materials (such as those indicated above) to provide monochromatic or multi-color light, typically red, green, or yellow. In camera embodiments in which the LED array comprises segmented LEDs, where the LEDs are divided into a grid of emissive and non-emissive regions, the effect of the non-emissive regions on images captured using one or more LED arrays can be compensated for by using one or more actuators to move the one or more LED arrays and / or at least one lens during the exposure duration of the scene to slightly shift the LEDs to illuminate areas of the scene that would be affected by the non-emissive regions. For array sizes larger than a 3×3 matrix, LED segments can be combined with integrated drivers to allow individually addressable functionality and achieve the small form factors desired for mobile devices without creating issues in the layout of the semiconductor layers used to create the integrated device.

[0091] Example Example 1 is a lighting device comprising: a light emitting diode (LED) die including a semiconductor stack, the semiconductor stack including an n-type semiconductor, a p-type semiconductor, and an active region sandwiched between the n-type semiconductor and the p-type semiconductor; and an anode under bump metallization (pUBM) electrically coupled to the p-type semiconductor and a cathode UBM (nUBM) electrically coupled to the n-type semiconductor, at least one of the pUBM or the nUBM having a substantially L-shape.

[0092] In Example 2, the subject matter of Example 1 includes wherein the substantially L-shape includes a relatively smaller rectangular area that extends in a direction substantially perpendicular to the relatively larger rectangular area at or near one end of the relatively larger rectangular area.

[0093] In Example 3, the subject matter of Example 2 includes, wherein one of the pUBM or nUBM has a substantially L-shape, and the other of the pUBM or nUBM has a substantially rectangular shape, and a distance between one of the pUBM or nUBM and the other of the pUBM or nUBM is substantially constant.

[0094] In Example 4, the subject matter of Example 3 includes, wherein an overall shape of one of the pUBM or the nUBM and the other of the pUBM or the nUBM substantially forms a square.

[0095] In Example 5, the subject matter of Examples 2-4 includes a tile having tile metallization formed thereon, at least one of the pUBM or the nUBM being electrically coupled to the tile metallization through a relatively small rectangular area via one of direct contact or soldering.

[0096] In Example 6, the subject matter of Examples 1-5 includes another LED die laterally adjacent to the LED die, the other LED die comprising another semiconductor stack including another n-type semiconductor, another p-type semiconductor, and another active region sandwiched between the other n-type semiconductor and the other p-type semiconductor; and another pUBM electrically coupled to the other p-type semiconductor and another nUBM electrically coupled to the other n-type semiconductor, at least one of the another pUBM or the another nUBM having a substantially L-shape and arranged to replicate the arrangement of the LED die.

[0097] In Example 7, the subject matter of Example 6 includes a tile having tile metallization formed thereon, wherein: a first of the pUBM or nUBM has a substantially L-shape and a second of the pUBM or nUBM has a substantially rectangular shape, a first of the other pUBM or another nUBM has a substantially L-shape and a second of the other pUBM or another nUBM has a substantially rectangular shape, and the tile metallization electrically couples the LED die and the other LED die together.

[0098] In Example 8, the subject matter of Example 7 includes, wherein a first one of the pUBM or the nUBM is electrically coupled to a second one of the other pUBM or the other nUBM.

[0099] In Example 9, the subject matter of Examples 7-8 includes, wherein: the substantially L-shape of the first of the pUBM or nUBM includes a relatively small rectangular area, wherein the relatively small rectangular area extends in a direction substantially perpendicular to the relatively larger rectangular area at or near one end of the relatively larger rectangular area, and the first of the pUBM or nUBM is electrically coupled to the tile metallization through the relatively small rectangular area of ​​the first of the pUBM or nUBM.

[0100] In Example 10, the subject matter of Example 9 includes wherein a second of the other pUBM or the other nUBM is electrically coupled to the tile metallization and to the first of the pUBM or nUBM via electrical connections between the tile metallization and the relatively small rectangular area of ​​the first of the pUBM or nUBM.

[0101] In Example 11, the subject matter of Examples 9-10 includes, wherein the electrical connection between the tile metallization and the relatively small rectangular area of ​​the first one of the pUBM or the nUBM is located to the LED die.

[0102] In Example 12, the subject matter of Examples 1-11 includes one of a printed circuit board (PCB) or a ceramic tile having tile metallization formed thereon, at least one of the pUBM or the nUBM being electrically coupled to the tile metallization; and a heat sink coupled to one of the PCB or the ceramic tile via a thermal interface material (TIM), the heat sink being configured to dissipate heat from the LED die.

[0103] Example 13 is a light emitting diode (LED) die comprising: a semiconductor stack including an n-type semiconductor, a p-type semiconductor, and an active region sandwiched between the n-type semiconductor and the p-type semiconductor; and an anode under bump metallization (pUBM) electrically coupled to the p-type semiconductor and a cathode UBM (nUBM) electrically coupled to the n-type semiconductor, at least one of the pUBM or the nUBM having a substantially L-shape.

[0104] In Example 14, the subject matter of Example 13 includes wherein the substantially L-shape includes a relatively smaller rectangular area that extends in a direction substantially perpendicular to the relatively larger rectangular area at or near one end of the relatively larger rectangular area.

[0105] In Example 15, the subject matter of Example 14 includes, wherein one of the pUBM or nUBM has a substantially L-shape, and the other of the pUBM or nUBM has a substantially rectangular shape, and a distance between one of the pUBM or nUBM and the other of the pUBM or nUBM is substantially constant.

[0106] In Example 16, the subject matter of Example 15 includes, wherein an overall shape of one of the pUBM or the nUBM and the other of the pUBM or the nUBM substantially forms a square.

[0107] In Example 17, the subject matter of Examples 14-16 includes one of a printed circuit board (PCB) or a ceramic tile having tile metallization formed thereon, at least one of the pUBM or the nUBM being electrically coupled to the tile metallization via a relatively small rectangular area.

[0108] In Example 18, the subject matter of Example 17 includes a heat sink coupled to one of a PCB or a ceramic tile via a thermal interface material (TIM), the heat sink configured to dissipate heat from the LED die.

[0109] Example 19 is a method of manufacturing a lighting device, the method comprising: epitaxially growing a semiconductor stack on a substrate of a light emitting diode (LED) die, the semiconductor stack comprising an n-type semiconductor, a p-type semiconductor, and an active region sandwiched between the n-type semiconductor and the p-type semiconductor; and forming at least one of an anode under bump metallization (pUBM) electrically coupled to the p-type semiconductor and a cathode UBM (nUBM) electrically coupled to the n-type semiconductor in a substantially L-shape.

[0110] In Example 20, the subject matter of Example 19 includes wherein the substantially L-shape includes a relatively smaller rectangular area that extends in a direction substantially perpendicular to the relatively larger rectangular area at or near one end of the relatively larger rectangular area.

[0111] In Example 21, the subject matter of Example 20 includes, wherein one of the pUBM or nUBM has a substantially L-shape, and the other of the pUBM or nUBM has a substantially rectangular shape, and a distance between one of the pUBM or nUBM and the other of the pUBM or nUBM is substantially constant.

[0112] In Example 22, the subject matter of Example 21 includes, wherein an overall shape of one of the pUBM or the nUBM and the other of the pUBM or the nUBM substantially forms a square.

[0113] In Example 23, the subject matter of Examples 20-22 includes forming tile metallization on the tile, and electrically coupling at least one of the pUBM or the nUBM to the tile metallization through a relatively small rectangular area.

[0114] In Example 24, the subject matter of Examples 19-23 includes disposing another LED die laterally adjacent to the LED die, the another LED die comprising another semiconductor stack including another n-type semiconductor, another p-type semiconductor, and another active region sandwiched between the another n-type semiconductor and the another p-type semiconductor; and electrically coupling another pUBM to the another p-type semiconductor, and electrically coupling another nUBM to the another n-type semiconductor, at least one of the another pUBM or the another nUBM having a substantially L-shape and arranged to replicate the arrangement of the LED die.

[0115] In Example 25, the subject matter of Example 24 includes forming tile metallization on the tile, a first of the pUBM or nUBM having a substantially L-shape and a second of the pUBM or nUBM having a substantially rectangular shape, a first of the other pUBM or another nUBM having a substantially L-shape and a second of the other pUBM or another nUBM having a substantially rectangular shape, and electrically coupling the LED die and the other LED die together using the tile metallization.

[0116] In Example 26, the subject matter of Example 25 includes, wherein a first one of the pUBM or the nUBM is electrically coupled to a second one of the other pUBM or the other nUBM.

[0117] In Example 27, the subject matter of Examples 25-26 includes, wherein: the substantially L-shape of the first of the pUBM or nUBM includes a relatively small rectangular area, wherein the relatively small rectangular area extends in a direction substantially perpendicular to the relatively larger rectangular area at or near one end of the relatively larger rectangular area, and the first of the pUBM or nUBM is electrically coupled to the tile metallization through the relatively small rectangular area of ​​the first of the pUBM or nUBM.

[0118] In Example 28, the subject matter of Example 27 includes, wherein a second of the other pUBM or the other nUBM is electrically coupled to the tile metallization and to the first of the pUBM or nUBM via an electrical connection between the tile metallization and a relatively small rectangular area of ​​the first of the pUBM or nUBM.

[0119] In Example 29, the subject matter of Examples 27-28 includes, wherein the electrical connection between the tile metallization and the relatively small rectangular area of ​​the first one of the pUBM or the nUBM is located to the LED die.

[0120] In Example 30, the subject matter of Examples 19-29 includes forming tile metallization on one of a printed circuit board (PCB) or a ceramic tile; electrically coupling at least one of the pUBM or the nUBM to the tile metallization; and coupling a heat sink to one of the PCB or the ceramic tile via a thermal interface material (TIM) to dissipate heat from the LED die.

[0121] Example 31 is at least one machine-readable medium comprising instructions that, when executed by a processing circuit, cause the processing circuit to perform operations to implement any of Examples 1-30.

[0122] Example 32 is an apparatus comprising means for implementing any of Examples 1-30.

[0123] Example 33 is a system implementing any of Examples 1-30.

[0124] Example 34 is a method of implementing any of Examples 1-30.

[0125] Although only certain features of the systems and methods have been illustrated and described herein, many modifications and variations will occur to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations. The method operations may be performed substantially simultaneously or in a different order.

[0126] Although the embodiments have been described with reference to specific example embodiments, it will be apparent that various modifications and changes may be made to these embodiments without departing from the broader scope of the present disclosure. Therefore, the description and drawings should be considered in an illustrative sense, and not in a restrictive sense. The drawings forming part of this specification show, by way of illustration and not limitation, specific embodiments in which the present subject matter may be practiced. The illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Therefore, this detailed description should not be interpreted in a restrictive sense, and the scope of the various embodiments is limited only by the appended claims and the full scope of equivalents to which such claims are entitled.

[0127] In this document, the subject matter may be referred to individually and / or collectively as the term "embodiment" for convenience only, and if more than one inventive concept is actually disclosed, there is no intention to actively limit the scope of this application to any single inventive concept. Therefore, although specific embodiments have been shown and described herein, it should be understood that any arrangement intended to achieve the same purpose can replace the specific embodiments shown. This disclosure is intended to cover any and all modifications or variations of the various embodiments. Upon reading the above description, combinations of the above embodiments and other embodiments not specifically described herein will be clear to those skilled in the art.

[0128] In this document, the terms "a" or "an," as commonly used in patent documents, include one or more than one, independent of any other instance or usage of "at least one" or "one or more." In this document, the term "or" is used to refer to a non-exclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein." In addition, in the claims that follow, the terms "including" and "comprising" are open-ended, that is, systems, UEs, articles, compositions, formulas, or processes that include elements in addition to those listed after such terms in the claim are still considered to fall within the scope of the claim. In addition, in the claims that follow, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects. For example, the term "processor" that is configured to perform a specific operation includes both a single processor that is configured to perform all operations and multiple processors that are individually configured to perform some or all operations (which may overlap), such that a combination of the processors performs all operations. In addition, the term "comprising" may be interpreted as meaning "including at least" the following element.

[0129] The Abstract of this disclosure is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as reflected in the following claims, the inventive subject matter has less than all the features of a single disclosed embodiment. Accordingly, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

1. A lighting device, comprising: A light emitting diode (LED) die comprising a semiconductor stack including an n-type semiconductor, a p-type semiconductor, and an active region sandwiched between the n-type semiconductor and the p-type semiconductor; and An anode under bump metallization (pUBM) electrically coupled to the p-type semiconductor and a cathode UBM (nUBM) electrically coupled to the n-type semiconductor, at least one of the pUBM or the nUBM having a substantially L-shape.

2. The lighting device according to claim 1, wherein the substantially L-shape includes a relatively smaller rectangular area that extends in a direction substantially perpendicular to the relatively larger rectangular area at or near one end of the relatively larger rectangular area.

3. The lighting device according to claim 2, wherein: One of the pUBM or nUBM has a substantially L-shape, The other of the pUBM or nUBM has a substantially rectangular shape, and The distance between one of the pUBM or nUBM and the other of the pUBM or nUBM is substantially constant. 4 . The lighting device according to claim 3 , wherein the overall shapes of one of the pUBM or the nUBM and the other of the pUBM or the nUBM substantially form a square. 5 . The lighting device of claim 2 , further comprising a tile having tile metallization formed thereon, at least one of the pUBM or the nUBM being electrically coupled to the tile metallization through a relatively small rectangular area.

6. The lighting device according to claim 1, further comprising: another LED die laterally adjacent to the LED die, the other LED die comprising another semiconductor stack including another n-type semiconductor, another p-type semiconductor, and another active region sandwiched between the another n-type semiconductor and the another p-type semiconductor; and Another pUBM electrically coupled to the another p-type semiconductor and another nUBM electrically coupled to the another n-type semiconductor, at least one of the another pUBM or the another nUBM having a substantially L-shape and arranged to replicate the arrangement of the LED dies.

7. The lighting device of claim 6, further comprising a tile having tile metallization formed thereon, wherein: The first one of the pUBM or nUBM has a substantially L-shape, and the second one of the pUBM or nUBM has a substantially rectangular shape, A first one of the other pUBM or the other nUBM has a substantially L-shape, and a second one of the other pUBM or the other nUBM has a substantially rectangular shape, and The tile metallization electrically couples the LED die and the further LED die together. 8 . The lighting device of claim 7 , wherein a first one of the pUBM or the nUBM is electrically coupled to a second one of the other pUBM or the other nUBM.

9. The lighting device according to claim 7, wherein: The substantially L-shape of the first one of the pUBM or the nUBM includes a relatively small rectangular area extending at or near one end of a relatively large rectangular area in a direction substantially perpendicular to the relatively large rectangular area, and The first one of the pUBM or nUBM is electrically coupled to the tile metallization through a relatively small rectangular area of ​​the first one of the pUBM or nUBM.

10. The lighting device of claim 9, wherein a second one of the further pUBM or the further nUBM is electrically coupled to the tile metallization and to the first one of the pUBM or nUBM via electrical connections between the tile metallization and the relatively small rectangular area of ​​the first one of the pUBM or nUBM.

11. The lighting device of claim 9, wherein the electrical connection between the tile metallization and the relatively small rectangular area of ​​the first one of the pUBM or nUBM is located to the LED die.

12. The lighting device according to claim 1, further comprising: one of a printed circuit board (PCB) or a ceramic tile having tile metallization formed thereon, at least one of the pUBM or the nUBM being electrically coupled to the tile metallization; and A heat sink is coupled to one of the PCB or the ceramic tile through a thermal interface material (TIM), the heat sink being configured to dissipate heat from the LED die.

13. A light emitting diode (LED) die comprising: a semiconductor stack comprising an n-type semiconductor, a p-type semiconductor, and an active region sandwiched between the n-type semiconductor and the p-type semiconductor; and An anode under bump metallization (pUBM) electrically coupled to the p-type semiconductor and a cathode UBM (nUBM) electrically coupled to the n-type semiconductor, at least one of the pUBM or the nUBM having a substantially L-shape.

14. The LED die of claim 13, wherein the substantially L-shape comprises a relatively smaller rectangular area extending at or near one end of a relatively larger rectangular area in a direction substantially perpendicular to the relatively larger rectangular area.

15. The LED die of claim 14, wherein one of the pUBM or nUBM has a substantially L-shape and the other of the pUBM or nUBM has a substantially rectangular shape, and a distance between one of the pUBM or nUBM and the other of the pUBM or nUBM is substantially constant.

16. The LED die of claim 14, further comprising one of a printed circuit board (PCB) or a ceramic tile having tile metallization formed thereon, at least one of the pUBM or nUBM being electrically coupled to the tile metallization through the relatively small rectangular area.

17. The LED die of claim 16, further comprising a heat sink coupled to one of a PCB or a ceramic tile through a thermal interface material (TIM), the heat sink configured to dissipate heat from the LED die.

18. A method of manufacturing a lighting device, the method comprising: epitaxially growing a semiconductor stack on a substrate of a light emitting diode (LED) die, the semiconductor stack comprising an n-type semiconductor, a p-type semiconductor, and an active region sandwiched between the n-type semiconductor and the p-type semiconductor; and At least one of an anode under bump metallization (pUBM) electrically coupled to the p-type semiconductor and a cathode UBM (nUBM) electrically coupled to the n-type semiconductor is formed in a substantially L-shape.

19. The method of claim 18, wherein the substantially L-shape comprises a relatively smaller rectangular area extending at or near one end of a relatively larger rectangular area in a direction substantially perpendicular to the relatively larger rectangular area.

20. The method of claim 19, wherein one of the pUBM or nUBM has a substantially L-shape and the other of the pUBM or nUBM has a substantially rectangular shape, and a distance between one of the pUBM or nUBM and the other of the pUBM or nUBM is substantially constant.

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