Process integration of 3D Si interposer with double-sided active chip attachments

A double-sided Si passive interposer connecting active dies on both sides for a 3D IC integration is investigated. This interposer is 100μm-thick with 10μm-diameter TSVs (through silicon vias), 3 RDLs (redistribution layer) on its front-side, 2 RDLs on its backside. It supports 2 active dies on its frontside and 1 active die at its backside. The present study focuses on the process integration of the passive interposer, double-sided chip assembly process, and passive electrical characterization.