Fluidic Self-Assembly Transfer Technology for Micro-Led Display

In this paper, we present a demonstration of high yield Fluidic Self-Assembly (FSA) technology to transfer gallium nitride (GaN) microchips which can be used for Micro-LED display. The low melting point alloy on the substrate and the metal electrode of the chip were assembled in heated solution by a simple shaking motion. More than 19,000 blue GaN microchips with 45um in diameter were precisely assembled at 99.90% yield within 1 min. At the chip sizes below 50um, this dramatic improvement in assembly yield was achieved by using a new assembly solution and chip designs. This low cost and fast demonstration has proven that FSA is a suitable mass transfer technology which is applicable to Micro-LED display after some further development.