Laser-Based Micro/Nano-Processing Techniques for Microscale LEDs and Full-Color Displays

Micro light-emitting diode (Micro-LED) display is an emerging display technology thanks to its high brightness, fast switching speed, and low power consumption. The commercialization of this technique is being explored by developing advanced processing techniques on an industrial scale. Recent ground-breaking advances in the manufacture of Micro-LEDs are mainly based on powerful laser micro/nano-processing techniques with the unique ability to fabricate materials, structures and devices with the advantages of non-contacting processing, high efficiency, adjustable coverage from micro- to macroscale and the compatibility with organic and inorganic materials. This paper categorizes, reviews and analyzes the main challenges and technical solutions in the Micro-LED displays by various laser manufacturing processes, covering chip dicing, geometry shaping, laser annealing, laser lift-off (LLO), laser-based Micro-LED transfer, laser-assist bonding (LAB) and laser repair. The fundamental principles of these techniques are discussed along with their basic mechanisms, followed by an exploration of the latest progress in the field. Finally, a detailed analysis of the advantages and disadvantages of these techniques is given, and the future research directions of laser techniques in Micro-LED display are discussed.