Micro-LED Precision Fabrication

High-resolution micro LED display for augmented reality, virtual reality, and mixed reality headsets that uses micro LEDs to provide full-color display without the need for color conversion elements. The display has a main board with micro LED chips arranged in pixels. Each micro LED has separate positive and negative electrodes. Wiring connects the electrodes internally and externally. A protective layer surrounds the micro LEDs and connections. The micro LEDs are transferred to the main board with lenses added. This allows full-color display without color conversion elements and prevents damage to the micro LEDs and driver during transfer.

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Micro-LED full-color display with monolithic integration of red, green, and blue LEDs on a single substrate to eliminate the need for mass transfer and simplify display manufacturing. The display is prepared by growing red, green, and blue LED epitaxial layers on a substrate, selectively etching to isolate the layers, and forming ohmic contacts and passivation layers. This allows precise control of each color's quantum well layers and contact points. The monolithic integration reduces complexity compared to transferring individual microLEDs.

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Full-color LED display unit with ultra-small pixel size and improved reliability by stacking RGB LED chips in layers separated by transparent dielectric layers. The LED chips are transferred from the wafer using chip transfer technology. This allows stacking and shrinking of the LED structure compared to side-by-side RGB chips. The stacked LEDs are driven by a single IC chip. The transparent dielectric layers protect the stacked LEDs and provide isolation between colors.

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Display module with improved bonding accuracy for micro LEDs. The module has a substrate with a region around the pixel area having higher surface energy. When bonding micro LEDs to the substrate electrodes, an adhesive layer is temporarily cured to move the excess adhesive from the pixel area to the higher surface energy region. This reduces thickness variation and misalignment of the micro LEDs compared to uniform adhesive. The higher surface energy area helps hold the micro LEDs in place during curing. The thinner adhesive between the electrodes reduces voids and gaps.

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Micro LED display device with simplified manufacturing by using a transparent substrate with pre-transferred micro LEDs, and forming the TFT electrodes on top using an organic TFT layer instead of transferring the micro LEDs onto TFT electrodes. This allows easier micro LED transfer and simplifies the manufacturing process compared to conventional micro LED displays. The device has a transparent substrate with exposed micro LED anode and cathode electrodes, a signal supply line layer on top, and an organic TFT layer with driving transistors on the supply lines.

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A method to manufacture microLED displays with higher yield and lower cost by selectively transferring microLEDs from a source wafer to a display substrate instead of transferring individually picked microLEDs. The method involves growing microLEDs on a source wafer, covering them with an adhesive layer, adding a backplane on the adhesive, and then removing the selected microLEDs and backplane to the display substrate. This avoids time-consuming and error-prone individual microLED transfer. It allows testing and selecting functional microLEDs on the source wafer before final assembly.

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Heterogeneous integrated full-color Micro-LED display panel with improved transfer and alignment method. The method involves growing blue-green dual-wavelength Micro-LED chips on one carrier and red Micro-LED chips on another carrier. Then, the carriers with the arrays of chips are aligned and bonded to a target substrate with electronics. This allows transferring and aligning a large number of Micro-LED chips in arrays without individual chip pick-and-place. The chips are bonded to the substrate through electrode holes filled with conductive material.

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Microdisplay chip with precise alignment and reduced volume when transferring LED chips to a PCB. The microdisplay chip has a transfer substrate with grooves for each LED chip. The LED chips are placed in the matching grooves on the transfer substrate. This prevents chip shifting during transfer and ensures accurate alignment when bonded to the PCB. The grooves also limit the LED chip thickness to prevent protrusion from the PCB. The LED epitaxy, current spreading layer, and bonding layers are all contained within the grooves. This reduces the overall display chip size.

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A method to improve the efficiency and yield of transferring micro LEDs from growth substrates to display substrates in order to fabricate micro LED displays. The method involves transferring micro LEDs of multiple colors from growth substrates to temporary substrates first. Then, micro LEDs of the same colors from the temporary substrates are simultaneously transferred to the display substrate. This reduces the number of transfers and improves yield compared to transferring individually from growth substrates. The temporary substrates have packed color arrangement for easier pickup and alignment.

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Active full-color MicroLED display device with improved yield and manufacturing efficiency by integrating the MicroLED array and driver circuitry on a single silicon substrate instead of transferring pre-made MicroLEDs. The device has a silicon substrate with an epitaxial layer of LED material on one side. MicroLEDs are formed on the epitaxial layer by etching. A pixel driving circuit is prepared on the other side of the substrate. This avoids the complex and low yield microtransfer method of attaching pre-made MicroLEDs to a display backplane.

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Micro LED display with transferable micro LEDs that have improved structural stability during transfer and reduced risk of damage. The micro LED structure has a support structure with a protrusion that contacts the support structure itself. This provides localized support to prevent bending and breaking during transfer. The support structure also has a suspended portion that avoids contact with the substrate during imprinting. The thickness and width of the protrusion and bridge arms are optimized for strength and stress regulation.

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Efficiently transferring arrays of micro LEDs using a stamping technique to improve the speed and yield of transferring large numbers of micro LEDs compared to pick-and-place methods. The method involves: 1. Preparing a source wafer with micro LEDs and a temporary carrier substrate with a stamping array. 2. Aligning the source wafer with the temporary carrier substrate. 3. Pressing the stamping array onto the source wafer to transfer the micro LEDs onto the temporary carrier substrate. 4. Removing the source wafer and preparing the temporary carrier substrate as the new source for the next transfer cycle. This allows transferring multiple micro LEDs at once using a stamping array instead of pick-and-place transfer of individual micro LEDs.

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Full-color micro-LED (µLED) display without electrical contact. It achieves a full-color display using a blue µLED grain emitting light through a down-conversion layer. The display uses upper and lower driving electrodes that do not directly interact with the µLED grain. A driving electric field recombines electrons and holes in the µLED to emit blue light. A down-conversion layer converts the blue light to yellow, which mixes with the blue light. The mixed light passes through a reflector and diffuser to form uniform white light. Color filters then convert the white light to red, green, and blue for full-color display.

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Efficiently forming micro LED displays by transferring micro LED wafers to a large transfer substrate with gaps between wafers. The gaps are larger than the initial micro LED spacing. This allows populating the display backplane in fewer steps compared to traditional methods. The micro LEDs are transferred in stages using the gaps: initial transfer for each color, gap fill rows, gap fill columns, and cross gap fill for each color. This reduces the number of transfer steps from hundreds to less than 20.

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Method for manufacturing a full-color micro LED display chip module that improves light intensity, eliminates crosstalk, and enhances yield compared to existing methods. The method involves preparing a monochrome micro LED chip on a substrate, grinding and cutting the chip, then flip-bonding it onto a driving substrate. The original substrate is peeled off to isolate the micro LED chip. A separate transparent substrate has quantum dot hole sites aligned with the micro LED subpixels. Quantum dots are filled in the holes and covered with a protective layer. A metal reflective layer is added outside the hole to enhance light and isolate crosstalk. The converted substrate is connected to the micro LED chip using transparent insulation. This allows independent fabrication of the quantum dot conversion device and micro LED module, improving yield.

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Display panel with improved bonding strength between LED chips and driving substrate, reducing damage and improving yield. The panel has separated island-shaped areas for each LED chip with hinge regions between them. This allows flexible deformation without damaging the bonds. The hinge regions have vias and connecting wiring to bridge between the islands. The panel is prepared by transferring a large number of LED chips to one side of the base substrate, then forming the thin film transistor array, driving function layer, and optionally a stretchable plate on the other side.

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MicroLED display screen design to improve yield, efficiency and reduce crosstalk between pixels. It uses vertical microLED chips with electrodes on opposite sides. The anode is connected to the circuit substrate and the cathode to a transparent conductive layer. This reduces bonding pad count and shielding compared to flip chips. A metal grid connects the cathodes in parallel. An opaque grid outside the emitting surface reduces inter-pixel crosstalk.

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RGB three-color integrated Mini-LED chip, manufacturing method, and display panel that simplify production and packaging of Mini-LED displays. The integrated chip contains all three RGB colors in a single mini LED instead of having separate red, green, and blue mini LEDs for each pixel. This reduces the number of transfer steps and improves yield compared to assembling discrete RGB mini LEDs. The manufacturing method involves growing an epitaxial layer with the three color LED layers stacked vertically. The chip is then diced to separate individual RGB integrated mini LEDs. This allows full-color displays using mini LEDs with simpler and more efficient transfer and assembly compared to discrete RGB mini LEDs.

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Full-color Micro LED display that reduces cost and improves yield compared to quantum dot conversion by directly emitting white light from a substrate with multiple color chips. The display is prepared by synchronously transferring multiple single-color chips from a wafer to a substrate with bonding pads. A white light fluorescent layer is then added on the chip side of the substrate. This converts the emitted light from each chip into white. A filter layer on top selectively reflects and filters non-target colors, leaving only the chip's original color. This way, red chips emit blue light when combined with the white fluorescence.

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A stable and reliable method for transferring microLED chips to a display substrate. The method involves transferring the microLED chips to the substrate while they are still attached to supporting pillars. This prevents poor electrical connections caused by solder overflow. The pillars provide space for the molten solder to surround the microLED without bridging to adjacent devices. The pillars are later removed to leave the microLEDs firmly connected to the substrate. This improves transfer stability and reliability compared to directly transferring bare microLEDs.

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Efficient and accurate transfer of micro LED chips onto a driving substrate for displays using a wafer-level preprocessing and packaging technique. The method involves extracting micro LED crystals from a wafer, placing them into square tubes, arranging the tubes in a pixelated array, cutting the array into sheets, and attaching the sheets to a driving substrate. This allows large numbers of tiny LEDs to be precisely transferred and assembled into displays using a wafer-level packaging process instead of pick-and-place.

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Micro LED display module with improved transfer precision, reduced defects, higher throughput, and better contrast. The module has a substrate with positioned recesses to match the micro LED chips. This avoids offset during transfer and improves yield. The recesses also prevent crosstalk between pixels. The module uses quantum dot materials for full color micro LEDs with better purity. It has a transparent black matrix to improve contrast. The micro LEDs are matched to the recesses with beveled edges to improve brightness. The display uses only blue micro LEDs for consistent brightness. The black matrix is applied first then transparent encapsulation avoids brightness loss.

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MicroLED display device with improved pixel geometry for reducing image distortion in enlarged projections. The microLED device has a mesa structure with multiple bosses, each with light emitting units forming square pixels. This shape reduces pixel distortion compared to rectangular pixels when projected at larger sizes. The mesa structure is formed by etching the microLED epitaxial layers. Contact holes are opened in an insulating layer above each boss to access metal layers below. This allows electrodes to connect to the light emitting units. The square pixels are formed by multiple light emitting units in each boss. The boss shape makes etching easier and enables uniform pixel geometry. The microLED chip array can be flip-chip bonded to a driving substrate.

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MicroLED display device with improved yield and simplified fabrication compared to conventional microLED displays. The device uses separate monochrome microLEDs for each color instead of integrating color conversion layers. The display is prepared by sequentially bonding and etching layers. A driving substrate, bonding layer, and monochrome microLED array are provided. A separate microLED epitaxial layer with avoidance holes is bonded over the monochrome LEDs. Etching exposes the monochrome LEDs and forms the separate color microLEDs. This reduces fabrication complexity compared to integrating color conversion layers on monochrome LEDs.

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High-resolution microLED display with improved color gamut and efficiency by using quantum dots as color conversion layers. The display has a monolithic microLED array on a silicon wafer with CMOS driving circuitry. The microLEDs have an inverted tapered structure with narrow top and wide bottom layers. Quantum dot layers convert the blue microLED emission to green and red. Color filters complete the display stack. The tapered microLED structure improves efficiency, and the quantum dots expand the color gamut compared to direct microLED colors.

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Micro LED display device that can meet the requirements of high resolution and has a high manufacturing yield. The device has a circuit substrate with micro LED units on one side and a metal conductive layer on the other side. The conductive layer contacts the epitaxial layer of the micro LEDs and has light conversion regions. A light conversion layer in some regions converts emitted light. Light-shielding structures on the epitaxial layer cover some areas. The metal layer is thicker than the epitaxial layer.

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A method to mass transfer microLEDs from their growth substrate to a display substrate with circuitry and pads for attaching the microLEDs. The method involves flipping the microLED-containing substrate, bonding the microLEDs to the display substrate using heat, then separating the flipped substrate. This allows transferring many microLEDs at once without individually picking them up. The display substrate has driving circuitry and pads for attaching the microLEDs. The separated microLED substrate is reflowed to fix the microLEDs in place. This avoids the mass transfer problem of picking up and placing many tiny microLEDs.

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Display device using microLED technology with improved luminous efficiency and production yield compared to conventional microLED displays. The device has microLED elements directly manufactured on the display circuit substrate. An insulating layer covers the lower sidewalls of the microLEDs. A common electrode layer covers the insulating layer and exposed top surfaces of the microLEDs. The common electrode layer contacts the upper sidewalls of the microLEDs. This configuration allows electrical connection to the microLEDs while leaving the top surface exposed for light emission. It provides efficient, compact, and direct microLED integration on the display substrate without transfer processes.

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Efficient manufacturing method for multicolor micro LED displays that avoids the challenges of transferring and interconnecting large numbers of micro LEDs. The method involves bonding the micro LED epitaxial layers directly onto the driving circuit chips during fabrication. This is done by sequentially bonding and removing the LED epitaxial wafers from the driving chip wafer to form a multilayer structure with the LED layers bonded to the circuit chips. This enables efficient fabrication of multicolor micro LED displays by eliminating the need for separate LED and driver wafers and subsequent transfer steps.

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A manufacturing method for high-precision, high-yield Micro-LED displays with improved transfer efficiency and light control. The method involves transferring multiple epitaxial wafers onto a temporary substrate, forming metal columns between adjacent LEDs, encapsulating each LED and column with a pixel limiting material, and adding a nanowire mesh layer between the limiting material and substrate. This prevents warping of the LED stack during transfer and improves bonding strength. The assembled Micro-LEDs are then transferred to the final display substrate.

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Micro light-emitting diode display panel that can be used for high reliability, high yield, high scalability, high selectivity and high success rate. The panel includes a backplane having a plurality of bonding structures, and a plurality of light-emitting diode dies disposed on the backplane and bonded with at least some bonding structures in the backplane.

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Display module with improved micro LED display technology that prevents ink from bleeding into the micro LED chips during color conversion printing. The display has a unique design with containment features to prevent ink overflow and improve display quality. The micro LED chips have recesses on their surfaces to hold the color conversion ink. A light absorption layer is filled between the recess walls and the color conversion layer to prevent lateral light crosstalk. A light reflection layer surrounds the recess to prevent uneven light emission. This containment and light management improves display contrast and uniformity compared to conventional micro LED displays.

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Flexible micro-LED display panel and manufacturing method that enables flexible displays with high yield and reduced wire disconnection. The panel uses materials like CPI substrates, aluminum-neodymium alloys for electronics, and TG-41 polymer for encapsulation. This allows the panel to bend without cracking and provides better electrical connections compared to traditional rigid materials. The thickness of the second base substrate is 8-12 um.

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Micro LED display screen with improved yield and reliability compared to conventional micro LED displays. The screen is made by stacking multiple substrates with through holes to expose the micro LED chips. This allows multiple micro LED chips to be bonded to each substrate instead of just one. The stacked substrates are electrically connected. This provides redundancy and improves yield by spreading defects across multiple chips. The through holes also allow better cooling and light extraction compared to a single substrate. The stacked structure can be manufactured by bonding and etching multiple substrates.

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A simplified manufacturing method for microLED display substrates that reduces complexity and cost compared to existing techniques. The method involves transferring all the red, green, and blue microLED chips in a single step instead of separate transfers for each color. This is achieved by adjusting the thickness of the microLED chips during growth so they are all equal. This allows transferring the microLEDs in a single process using a common technique, rather than three separate transfers for each color. This simplifies the manufacturing process, reduces cost, and improves yield compared to transferring microLEDs with different thicknesses separately.

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Flip-chip GaN-based Micro-LED display module with improved reliability and efficiency for display applications. The module uses individual small GaN-based Micro-LED chips without a common cathode layer. The Micro-LEDs have a flip-chip structure with the LEDs directly bonded to the circuit substrate. This avoids the issues of common cathode reliability, electrode crossing, and light crosstalk. The small size of the Micro-LEDs reduces the risk of breakage during manufacturing. The substrate-free design eliminates the need for substrate removal steps that can damage the common cathode.

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A pixel unit for displays with a micro LED emitter and integrated driver IC to reduce wiring complexity and improve yield. The pixel unit has a micro LED with electrodes, a photoresist layer around it, and a transparent shell encapsulating the components. The driver IC has solder pads on its backside. Electrical connection sheets and pads connect the IC pads to the micro LED electrodes. The shell exposes the top surfaces of the components. A transparent conductive film on the shell electrically connects them. This allows electrical connection to the micro LED and IC without wires inside the shell.

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Micro LED display chip with improved luminous efficiency and preparation method. The chip has micro LED units with a reflective layer on the sidewall instead of the top surface. This avoids light crosstalk between pixels and improves extraction. The reflective layer is formed by etching from the sidewall of the stepped micro LED structure. The etching is done without a mask since the stepped shape provides positioning. This saves process steps compared to etching from the top.

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Micro-LED display manufacturing method and micro-LED display that enables mass production of micro-LED displays by integrating the micro-LEDs and active matrix TFTs on the same substrate. The method involves forming the micro-LEDs with multiple subpixels and wavelengths on the substrate, then integrating TFTs and other display elements without transferring the micro-LEDs. This allows fabricating the micro-LED display in a monolithic process.

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Method for manufacturing displays using self-assembly of micro LEDs to increase yield and enable large-scale production. The method involves transferring micro LEDs grown on a source substrate to a temporary board with sacrificial layer. Then, cells on an acceptor board are filled with fluid and aligned with the temporary board. An electric field is applied to move the micro LEDs from the temporary to the acceptor board while maintaining interval. This allows precise placement of micro LEDs in cells without alignment errors. The temporary board is removed and the micro LEDs are fixed in place on the acceptor board. This enables high-yield transfer of micro LEDs from the growth substrate to the display board using self-assembly.

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Micro LED display device with reduced crosstalk and improved brightness. The device has a reflecting layer on the side walls of the LED units to prevent light leakage and crosstalk between adjacent pixels. This is achieved by a fabrication process where a sacrificial layer is deposited first, then the reflecting layer, and finally the sacrificial layer is removed. This allows forming the reflecting layer only on the side walls without etching. The reflecting layer blocks spontaneous emission from the side walls and reflects light back into the LED, improving brightness. The reflecting layer is discontinuous due to the sacrificial layer thickness, allowing stripping of both together.

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An efficient and reliable encapsulation and transfer method for LEDs with small chip sizes like Mini and Micro LEDs. The method involves pre-applying black liquid resin adhesive around the edges of the LED die on the wafer before transfer. This prevents light interference from side surfaces when the LEDs are transferred and assembled into displays. The black resin fills the gaps between dies and covers bumps. After transfer, the black resin cures and seals the LEDs. This prevents light leakage from the sides. The method avoids building dams between chips or using complex processes to prevent side light interference.

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Method for encapsulation and transfer of Mini LED or Micro LED that improves efficiency, precision, yield, and display quality compared to conventional methods. The method involves filling a cutting groove around each chip on the wafer with black liquid resin before transfer. This prevents light interference between adjacent chips when they are transferred and encapsulated in groups. The black resin glue also prevents chip displacement during encapsulation. The steps are: 1) Cutting the wafer with grooves around each chip, 2) Filling the grooves with black liquid resin, 3) Transferring multiple chips together with the resin, 4) Encapsulating the chips with resin, avoiding light mixing and misalignment issues.

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A simplified method for manufacturing microLED displays that reduces the complexity and cost of transferring large numbers of microLED chips from a source substrate to a destination substrate. Instead of direct or indirect transfer methods, the microLEDs are first transferred to an intermediate substrate using a technique like electrostatic adsorption. The intermediate substrate with the microLEDs is then bonded to the destination substrate. After bonding, the intermediate substrate is removed, leaving the microLEDs on the destination substrate. This eliminates the need for complex and expensive direct or indirect transfer methods involving bonding and peeling steps.

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Manufacturing a micro LED display substrate that can be used for digital cameras and other mobile devices. The substrate includes forming an array of micro LEDs on an epitaxial wafer, transferring the array of micro LEDs on the epitaxial wafer to an adhesive layer on a surface of a transfer substrate assembly, and transferring the array of micro LEDs on the surface of the transfer substrate assembly onto corresponding pads on a driving substrate respectively.

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Micro-LED display structure with high-yield manufacturing. The LED structure includes an LED driving circuit with conductive pads that contact some LED units. This allows selective bonding of LED units to the circuit through the conductive pads. The remaining LED units without pads are dummy units. This prevents the need for precise alignment of every LED unit during bonding. It enables high-yield micro-LED fabrication of high-resolution displays with micro/nano-sized LEDs.

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A method for manufacturing micro LED displays with improved yield and reduced cost compared to conventional methods. The method involves transferring micro LED chips directly from their growth substrate to a separate substrate with drive circuits and bonding pads. This allows mass transfer of the active LED chips without the complexity and yield issues of epitaxially growing and processing the entire display on a single substrate. The transferred micro LED chips are fixed in place and connected to the drive circuits. This allows using optimized growth substrates for each color of LED and simplifying display substrate processing.

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A Micro-LED display substrate with improved color accuracy and reduced crosstalk compared to conventional stacked Micro-LED displays. The substrate has three layers, each containing a primary-colored Micro-LED array. The layers are stacked but not overlapped vertically, allowing independent control of the LEDs in each layer. This avoids chromatic aberration and crosstalk issues when stacking red, green, and blue LEDs in vertical alignment.

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A manufacturing method for micro LED displays that solves the mass transfer problem of transferring large numbers of microscopic LED chips from a growth substrate to a display substrate. The method involves directly transferring the micro LED chips from their growth substrate onto the display substrate without intermediary steps. This is achieved by using specialized equipment to pick up and place the micro LED chips onto the display substrate with precision alignment. This allows transferring thousands or millions of micro LED chips from the growth substrate to the display substrate in a single step, avoiding the time-consuming and low-yield process of transferring individually. The method involves using a platform with XY and Z stages to move the growth substrate with micro LED chips over the display substrate. The micro LED chips are picked up from the growth substrate and placed onto the display substrate using a specialized tool. This allows accurate alignment and transfer of the micro LED chips

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A method to improve the alignment precision and yield of micro LED displays by reducing the number of transfer steps. The method involves preparing the micro LED on a temporary substrate instead of the final display substrate. Then the temporary and display substrates are aligned and the micro LED is transferred in one step. This avoids separate transfers from sapphire growth substrate and temporary carrier, reducing misalignment risks.

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