Mass transfer, detection and repair technologies in micro-LED displays

Micro-light emitting diode (micro-LED) is an emerging display technology with excellent performance of high contrast, low power consumption, long lifetime, and fast response time compared the current (e.g., liquid crystal organic LED (OLED)). With technological advantages, micro-LED holds promise to be widely applied in augmented reality (AR), flexible screens, etc. thus regarded as next generation technology. In process flow micro-LED, step known mass transfer that requires transferring millions micro-LEDs from a growth substrate plane, one key challenges limiting commercialization laboratory. Worldwide academic industrial efforts have been devoted developing strategies purposes improving yield reducing cost. Herein we review three main categories technologies for (pick-and-place, fluid self-assembly laser-enabled advanced placement) coupled detection repair after transfer. Discussions comparisons provided about underlying general principle, history, representative parties, disadvantages (yield/efficiency/cost) these technologies. We further envision application prospect future micro-LED.