3D Stacking Process with Thermo-Sonic Bonding Using Non-conductive Film

In this research, a combination of thermo-sonic bonding (TSB) process and non-conductive film (NCF) material was used to fabricate vertically stacked through silicon via (TSV) assemblies. TSB is particularly attractive TSV assembly process because it offers up to 10x throughput improvement when compared to conventional processes. By adjusting the properties (e.g. viscosity, and reaction time) of NCF, a 4-layer stacked assembly was fabricated without voids or delamination. Moreover, these parts exhibited no failures after 2,000 times thermal cycles test (-40ºC to 125ºC).