Dielectrophoretic Assembly, Repair, and Transfer Technology for Micro‐LED Display Boosted by Injection‐Suction Printing

ABSTRACT Micro‐LED displays offer high brightness, high efficiency, and fast response, but large‐area manufacturing still faces challenges. However, reducing chip‐solution waste and repairing poor sub‐pixels are critical challenges that should be addressed for the commercial production of micro‐LED displays. Here, we present a dielectrophoretic injection‐suction printing (DEP‐ISP) process for fluid assembly of micro‐LED chips. This method reduces chip‐solution consumption, controls chip orientation using the DEP field, positions chips through subpixel grooves, and enables repair of misaligned chips. Using this approach, micro‐LED chips were assembled in a metal‐down, face‐selective manner at 390 subpixel sites per test cell, achieving an assembly yield of 99.8% and an orientation yield of 100% across six test cells. The assembled chips were then transferred to a PDMS/glass substrate under DEP conditions, producing a micro‐LED array device with an average displacement error of 1.62 µm and a transfer yield of 100%. SiO 2 shell engineering further improved assembly selectivity, while repair processing increased the yield of misassembled chips. Although electrical performance still requires optimization, the successful turn‐on of some emitters confirms the feasibility of DEP‐ISP for micro‐LED integration. This study demonstrates a scalable route for micro‐LED assembly, repair, and transfer toward large‐area display fabrication.