Review on Fan-Out Packaging of Light-Emitting Diodes: Process Route, Manufacturing Reliability and Performance Optimization

With the continuous growth of the demand for high resolution and high contrast in the display field, Light-Emitting Diodes(LED) are evolving towards miniaturization and smaller pitch. Fan-Out Packaging(FOP), represented by Fan-Out Wafer Level Packaging(FOWLP) and being an advanced LED packaging technology, does not require a substrate or wire bonding while featuring a small size, low cost, and the ability to provide efficient electrical interconnection and good heat dissipation for LED chips. It is a promising packaging solution that promotes the miniaturization of LEDs. This article introduces two types of FOPs, FOWLP and FOPLP, and three FOP process routes: Chip-First and Face-Down, Chip-First and Face-Up, and RDL-First, and reviews the research progress on the manufacturing reliability issues of FOPLEDs, including die shift and warpage deformation, as well as the research progress in optimizing the electrical, optical, and flexible performance of FOPLEDs.