Evaluation of directed self-assembly process for LED assembly on flexible substrates

This paper reports on a directed self-assembly process for LED assembly on a large area flexible substrate. The presented approach involves fluidic handling of small semiconductor dies and their directed self-assembly on the flexible substrate using a magnetic force. A thick lightweight layer created on the die surface is used as a buoyant layer. Techniques and yields for introduction of dies into liquid with correct top/down orientation are presented. Influence of process parameters and carrier liquid on die pickup using magnetic force is evaluated.