High reliability underfill encapsulated fine pitch system on flex packages


In system on flex (SOF) packages with high density I/O's, larger die size, and fine pitch, the mismatch of material properties between the silicon die, underfill (encapsulant) and flexible substrate induces concentrated stress field around the bonded areas (Bumps & traces) during assembly process. The concentrated stresses result in delamination on various… (More)


15 Figures and Tables