Study on low temperature Cu bonding and temporary bond/de-bond for RDL-first fan-out panel level package

Abstract

In this study, Cu-Cu bonding with pillar-concave structure on a polymer layer was investigated to realize better bonding quality at lower temperature, while a low-stress release layer for temporary bond and de-bond by laser ablation was demonstrated to handle a glass panel for re-distribution layer (RDL) process. The low temperature technology can be potentially applied for RDL-first fan-out panel level package (FOPLP).