Hybrid Integration Techniques for Micro-LED Displays

An augmented LED array assembly for high-lumen lighting applications, such as automotive headlights, improves the integration of the LED array with electrical connections and heat dissipation. The LED array assembly includes a micro-LED array mounted on a driver IC bonded to contact pads on a flexible PCB. This eliminates wire bonding and allows accurate connection of the LED array to the PCB. The PCB can be flexed to accommodate different form factors. The PCB is attached to a heat spreader for thermal management.

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Hybrid integration in micro-LED with backplanes reduces cost and improves performance. The LED array is fabricated separately from the control circuitry. A thin-film circuit layer is deposited on the LED array to control the LEDs. The backplane with drive circuitry is then bonded to the circuit layer using a reduced number of metal bonds. This allows the LEDs to act as the support structure for the circuitry, reducing bump count. The thin-film circuits can be interconnected to further reduce bonds. The bonding uses low-temperature bumps to avoid mismatches.

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A method and device structure for fabricating high-performance microLED displays with improved pixel density, efficiency and integration compared to conventional approaches. The method involves hybrid bonding of the microLED array wafer to a CMOS driver circuit wafer without using through-silicon vias. The microLEDs are individually connected to CMOS circuitry using contacts on the bottom side of the microLED wafer and matching contacts on the CMOS wafer. This allows dense microLED arrays to be seamlessly integrated with CMOS circuits without sacrificing pixel fill factor or performance.

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A manufacturing method for LED-based display chips with improved electrical connections. The method involves forming trenches that cross through the LED stack and substrate to isolate the LED area. This allows separate electrical connections to the LED and circuit areas on the chip surface. The trenches are filled with insulating material except at the bottom where they expose the LED layer. This allows electrical access to the LED without shorting it through the control circuit. The method involves depositing metal layers on the substrate and LED stack, bonding the LED stack to the substrate, then forming the trenches.

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Light emitting diode (LED) assembly which improves light efficiency, a light quantity, and an integration degree through optimized alignment of vertical type micro LEDs each having a nano size or micro size. The assembly includes a substrate provided with a plurality of through holes formed in a thickness direction, micro LEDs each formed in a vertical type in which a vertical width is greater than a lateral width, and aligned in an upright state by being at least partially inserted into the through holes of the substrate.

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A monolithically and heterogeneously integrated micro-LED display chip with high resolution, large driving current, high brightness, and low voltage. The chip is prepared by integrating a monolayer transition metal dichalcogenide (TMD) transistor matrix with micro-LEDs using back-end-of-the-line (BEOL) processing steps. The TMD transistor matrix provides high resolution and current driving capability.

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Display panel that is capable of independent pixel control, independent light emission control, high luminance, low power consumption, ultra-high resolution and high colorfulness. The panel includes a substrate, a driving circuit layer, where the driving circuit layer is disposed on a side of the substrate, and includes a plurality of driving circuits; and an LED element layer, where the LED element layer is disposed on a side of the driving circuit layer facing away from the substrate, and includes a plurality of micro-LED elements which are electrically connected to the plurality of driving circuits in a one-to-one correspondence through via holes in the plurality of driving circuits.

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Micro LED display structure and fabrication method to improve yield and processing. The structure involves a removable connecting layer between the micro LED and substrate, covered by a layer on the LED surface. This allows easier removal of the connecting layer compared to sputtered coatings. The covering layer contacts an isolation layer, preventing micro LEDs from touching during removal. The display has circuit substrate pads, covered micro LEDs, and isolation between them.

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A compact, flip-chip based LED lighting solution that enables higher packing density and improved thermal management compared to wire bonded LED chips. The solution uses flip-chip integrated circuits (ICs) and flip-chip LEDs that are directly soldered onto a substrate without wires. This allows the LED flip-chips to be closely packed around the IC flip-chip on the substrate. The IC flip-chip has customized flip-chip pads with specific layout conditions to accommodate this dense packing. The pads are arranged within a boundary with at least one pad outside the boundary. This allows the LED flip-chips to be electrically connected to the IC flip-chip without wire bonds. The LED flip-chips are then covered with a light-permeable package to create a compact LED assembly.

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Micro light emitting diode module which reduces light leakage and enhances color contrast and chroma. The module includes multiple flip-chip LEDs and a dielectric layer. The dielectric layer is formed on the electrical connecting side of each flip-chip LED. The dielectric layer has multiple electric channels in which multiple electrical circuits are formed and corresponded to the p-contact pads and the n-contact pads of the flip-chip LEDs respectively.

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Self-aligning assembly of microelectronic components like driver circuits and pixel circuits in displays, using solder bumps. The components are temporarily placed on carrier plates and then joined with the substrate. When the solder is reflowed, the components self-align due to their flip-chip interconnections. This allows precise placement of densely packed micro components without precise alignment during assembly. It enables high yield, low cost, and fast assembly of displays with millions of micro components like LED pixels and driver circuits.

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