Microscale material characterization and viscoelastic modeling of organic dielectic thin film in eWLB package

This paper is supposed to discuss the suitability to identify material parameters via nanoindentation of a viscoelastic dielectric thin film attached to a rigid substrate. In microelectronic components, polymer thin films used as packaging materials are gaining more and more importance, thus the full thermo-mechanical characterization of these materials is highly desired. Therefore, in this paper the problem of indentation into a geometrically confined thin film is indicated. With the help of FEM simulations, a function which accounts for the substrate influence in spherical nanoindentation is developed and integrated in the viscoelastic analysis of material parameters. By using a precise laser heat option as add on to the standard nanoindenter equipment (Agilent G200), time and temperature dependencies could be identified in micro scale and compared to conventional thermo-mechanical macroscopic thin film characterization. In both size scales, material models were established and verified in FEM simulation of sphere indentation. Transfering viscoelastic material characterization via nanoindentation onto thin polymer films over a wide range of temperatures and comparing microscopic and macroscopic results, as shown in this paper, is still not a well explored research field.