Flexible Fan-Out Wafer Level Packaging of Ultra-Thin Dies

Recent developments in the integration of ultra-thin silicon dies within a flexible film have led to a new paradigm. Indeed, thanks to the thinness and flexibility of devices, it is conceivable that functions can be added around any object without changing its aspect. A new technology, presented in this paper, proposes the integration and fan-out of ultra-thin silicon dies within a flexible label. The process is performed on a wafer carrier in a microelectronic manufacturing line. Working with silicon wafers helps achieve high resolution of integration. The process includes flip-chip bonding and collective die thinning. Flexible labels were fully tested at the wafer level and after separation from the carrier. Electricals results on test vehicle are presented in this paper and reliability was addressed. This study is a first step towards a complete electronic system in a flexible label.