The latest developments in electronics packaging materials and processes are discussed. The emerging technologies including the system in package (SiP), system on package (SOP) and system on chip (SOC), are presented. The SiP technology use discrete active and passive components to achieve higher density through chip or package stacking. The developments of three key materials, including package or board materials with high modulus for thin film build-up wiring, package materials with low coefficient of thermal expansion (CTE) and ultra-low loss and thin film low-stress dielectrics for reliable wiring.