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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source

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.

Source