Pre-applied inter chip fill for 3D-IC joining

Abstract

For the conventional two dimensional (2D) packagmg of mtegrated circuit (IC), reflow and capillary under fill have been used for more than a decade. But for the purpose of low power and high performance of IC, three dimensional IC (3D-IC) have been proposed in recent years. In case of 3D-IC both bump pitches and gaps between stacked thin chips should be fine and narrow, so that pre-applied niter chip fill (ICF) which is applied m thermal compression bonding have been proposed. In tins process, not only low viscosity but also thermal conductivity is simultaneously required. In this study, some of selected epoxy based matrix and filler were simulated and evaluated for pre-applied ICF. we confirmed its process applicability to pre-applied chip bonding. Physical characteristics of cured ICF and void-less jommg were also discussed.