Through Silicon Vias and thermocompression bonding using inkjet-printed gold nanoparticles for heterogeneous MEMS integration

We present a novel technique for heterogeneous integration using gold filled Through Silicon Vias (TSV) and thermocompression bond bumps formed in a single fabrication step, using gold nanoparticles dispensed by inkjet printing. Gold-filled TSV arrays (12 × 12, via radius 50μm, pitch 250μm) have been demonstrated using this method. Void free, filled TSVs are reported, and thermocompression bonding yielded seamless interfaces. Die shear tests show good bond strength, and sub-Ω via resistances were measured. The presented integration process exhibits a low temperature budget (≤250°C), allows good alignment, and is compatible with substrates of different sizes and materials, enabling the heterogeneous integration of known-good-dies (KGD) which may have been fabricated in different technologies.