Fabrication of High-Resolution Active Matrix Micro-LED Display Based on Direct Laser Mass Transfer

Mass transfer technology represents a critical bottleneck limiting the mass production of large-sized micro-LED displays. This study proposes a high-resolution direct laser mass transfer process utilizing a receiving tape, successfully fabricating a 3.8 in. 1280 × 1024 green active matrix micro-LED display with 431 PPI and 58.88 μm pixel pitch. The receiving tape with excellent adhesion, high-temperature fluidity, and chip-catching capability was prepared via anionic polymerization and a comma scraping roller process. The micro-LED chips were directly transferred from the chips on the wafer (CoW) to the thin-film transistor (TFT) backplane using a 248 nm KrF excimer laser, significantly simplifying the transfer process. Combined with a flexible laminated bonding structure, high-precision transfer and high-yield thermocompression bonding of the micro-LED array to the TFT backplane were achieved, achieving an illumination yield of 99.39%. Comprehensive analyses were conducted on the morphology of the transferred chips, the bonding interface of the bonded chips, and the key optical performance parameters. The process developed herein provides a scalable solution for the large-scale manufacturing of micro-LED displays, holding significant potential to accelerate the commercialization of micro-LED technology.