A study of chip-last embedded flip-chip package

Flip-chip chip-scale packaging (FCCSP) has recently emerged as a package solution achieving superior performance over traditional wire-bonding technology. There are also further possible advances for the assembly process such as under-fill and molding to be more cost effective. We propose an innovative process of a heterogeneous integration of the organic substrate and the standard FCCSP assembly process. This is achieved with technical and material improvements; the result is a new type of molding and under-fill technology that has higher process efficiency than conventional molding and under-fill and demonstrates good thermal dissipation and warpage control. The new process and the resulting package reliability are validated by test vehicle engineering verifications. This 'laminated' FCCSP platform is a type of 'chip-last embedded die' structure that is extendable to support stackable packages for use in advanced package-on-package applications.