Ultra-Thin QFN-Like 3D Package with 3D Integrated Passive Devices

Abstract

In this work, a new wafer-level 3D packaging technology is developed to enable integration of an ultra-thin QFN-like (quad-flat no-leads) 3D package that targets both effective electrical and thermal properties and a thickness smaller than 200 µm. The proposed architecture allows 3D interconnection of stacked staggered dies and integration of compact, high-performance 3D integrated passive devices inside the package for added functionality and electrical performance. The developed technology consists of using debonding from a temporary carrier, Cu 2D-RDL (Redistribution Layer), accurate thin die pick & place, 3D-RDL and overmolding processes to integrate a QFN-like 3D package. Interconnection between die and package I/O is achieved using conformal 3D-RDL, thus without wire-bond, flip-chip or TSV.