High Consistency Techniques for Micro-LED Manufacturing
5 patents in this list
Updated:
Manufacturing micro-LED displays requires precise control across multiple process steps, with current techniques achieving yields below 99.99% at the individual LED level. When scaled to a 4K display containing over 24 million pixels, even small defect rates become significant manufacturing challenges, particularly for maintaining consistent optical and electrical properties across the array.
The fundamental challenge lies in balancing transfer speed and precision while maintaining uniformity in both the physical placement and performance characteristics of each micro-LED.
This page brings together solutions from recent research—including laser-assisted selective transfer methods, segmented substrate approaches, redundant LED architectures, and specialized bonding pad designs. These and other approaches focus on improving manufacturing consistency while maintaining the high throughput needed for commercial production.
1. Segmented Micro LED Transfer Method with Simultaneous Substrate Allocation
POINT ENGINEERING CO., LTD., 2023
Manufacturing method for micro LED displays that reduces time for transferring the micro LEDs from the growth substrate to the final display substrate while preventing non-uniformity of luminous properties. The method involves segmenting the micro LED regions on the growth substrate and simultaneously transferring the segmented regions to separate display substrates. This allows efficient transfer of all the micro LEDs without waiting for simultaneous transfers from the growth substrate. The segmented arrangements on the display substrates also prevent luminance and color uniformity issues.
2. Laser-Assisted Micro-LED Transfer with Anisotropic Conductive Layer
Goertek, Inc., 2019
Method for transferring micro-LEDs to a receiving substrate to enable micro-LED manufacturing of high-quality displays. It involves using a laser to lift off micro-LEDs from the original substrate and transfer them to a receiving substrate. An anisotropic conductive layer makes electrical contact with the receiving substrate pads. This avoids complications of pick-up tools and multiple transfers. The laser lift-off enables easy transfer without damaging the micro-LEDs.
3. Laser-Assisted Solder Bump Heating for MicroLED Flip-Bonding to Mitigate Thermal Expansion Misalignment
LUMENS CO., LTD., 2019
Method of fabricating microLED displays with improved alignment and yield when flip-bonding microLEDs onto submounts. The method overcomes misalignment caused by different thermal expansion coefficients between the microLED's sapphire substrate and the silicon submount. Instead of standard flip-bonding that heats solder bumps to melt and connect the microLED electrodes to the submount contacts, the improved method uses lasers to selectively heat the solder bumps without heating the substrates. This prevents misalignment due to different thermal expansion.
4. Micro LED Lighting Device with Redundant LED Activation and Bypass Mechanism
ACER INCORPORATED, 2019
Micro LED lighting device with a repair mechanism to improve manufacturing yield and enable in-situ repair. The device has a redundant micro LED that can be activated if the main micro LED fails. The redundant LED has separate electrical connections that can be switched on to bypass the main LED. The repair mechanism allows the redundant LED to be activated and connected when the main LED fails, providing a backup lighting source. This allows failed micro LEDs to be repaired by switching to the redundant LED. The repair mechanism improves yield and product reliability.
5. Micro-LED Light-Emitting Unit with Strip-Shaped Element and Bonding Pins for Enhanced Alignment Tolerance
Shanghai Tianma Micro-Electronics Co., Ltd., 2019
A light-emitting unit for displays that uses micro-LEDs and bonding pads with specially shaped pins for improved yield and uniformity. The micro-LED has a strip-like element pin with length>width and nonzero angle to the strip-like bonding pin. This allows easier alignment and welding between the pins with lower precision. The strip shape gives a larger tolerance for pin misalignment compared to point-like pins.
Because of their complex production process, micro-LED components were previously difficult to produce consistently. This barrier has been removed by advances in transfer printing and laser-assisted processes. As a result of these trustworthy and efficient techniques, the manufacturing of micro-LED displays has expanded significantly.
