Low Cost Si-Less RDL Interposer Package for High Performance Computing Applications

A new concept of Si-less redistribution layer (RDL) platform was proposed for server/HPC application with advantages of packaging cost reduction, warpage control, and enhanced reliability. In this paper, RDL interposer package with size larger than 3000mm2 was fabricated. Warpage behavior, electrical performance and reliability of the RDL interposer package were evaluated. In order to predict warpage behavior of RDL interposer, the critical factors were defined. The electrical performance between Si interposer and RDL interposer was analyzed using electrical simulation and finally joint reliability was also compared in terms of predicted joint stress.