Integrated Process of a Micro-LED Panel for Full-Color Panoramic Head-Up Displays Based on Laser-Assisted Transfer and Laser Bonding Technology

To address the urgent demand for high reliability, high brightness, and high-resolution displays in automotive panoramic head-up display (PHUD) applications, this study proposes a high-reliability micro-LED panel-level integration technology tailored for PHUDs. The research focuses on resolving the challenges of high-precision transfer and interconnection of micrometer-scale chips encountered during the large-scale manufacturing of micro-LEDs. An electroless nickel/immersion gold (ENIG) process was employed to fabricate the electrodes of the thin-film transistor (TFT) backplane. Combining laser-assisted transfer and laser-assisted bonding (LAB) technologies, a 6.2 in. full-color micro-LED display panel with a resolution of 624 × 360 and 116 PPI was successfully fabricated, achieving a high color gamut (121.3% NTSC). The formation mechanism of intermetallic compounds (IMCs) at the bonding interface and the brightness spectrum of the micro-LED array were analyzed in detail. By optimizing the encapsulation materials and processes, the ghosting effect of the display module was significantly reduced, thereby enhancing driving safety. Experimental results demonstrate that this technology provides a scalable manufacturing framework for safety-critical display applications. The module yield exceeded 99.99%, which meets the requirements of automotive applications for brightness uniformity and operational stability.