FOWLP-based Flexible Hybrid Electronics I: Photobiomodulation Device Fabrication on Hydrogel Substrate Using RDL-first Approach

This paper focuses on the fabrication of a PhotoBioModulation (PBM) device as a kind of flexible hybrid electronics (FHE) with a hydrogel substrate. PBM is a type of phototherapy using visible or near-infrared (NIR) light from LEDs or lasers. We propose an integrated PBM patch using RDL (redistribution layer)-first fan-out wafer-level packaging (FOWLP) with an array of embedded NIR mini-LEDs in the hydrogel as a substrate for chronic wound or bedsore healing. This paper characterizes the fan-out wirings formed on the hydrogel and describes multichip-to-wafer bonding with the mini-LEDs.