Workability and reliability assessment of various high bandwidth PoP structures

Package-on-package has become the mainstream solution for the high bandwidth package which is used between application processor and memory of a smartphone. In order to get bandwidth increased, one way is to increase the number of data I/O, consequently the size and pitch of interconnects have to be reduced. Therefore, an improvement of current PoP structure to increase the number of interconnects and to reduce the pitch become very important and imperative. In this work, three High Bandwidth PoP (HB PoP) structures are proposed and investigated in workability, reliability, and high/room temperature warpage performance through fabricating. Compared with conventional PoP, the study shows that the proposed HB PoPs have superior reliability and warpage performance, and is comparable workability with conventional PoP.