Demonstration of a Heterogeneously Integrated System-on-Wafer (SoW) Assembly

This paper describes the integration of a System-onWafer (SoW) assembly using test dielets mounted on a Silicon Interconnect Fabric (Si-IF) with an inter-dielet spacing of 100 μm and using 10 μm interconnect pitch. The continuity within and across the dielet assembly is shown using daisy chains of Au-capped Cu-Cu thermal compression bonds. The daisy chains run not only through every dielet but also across all the adjacently mounted dielets on the Si-IF. The interconnections exhibited an effective contact resistivity of 0.8-0.9 Ω-μm
²
and an average shear strength of 125 MPa. Our investigations showed that Argon plasma pre-treatment improves the shear strength of the metal bonds by a factor of 5X. Thermal simulation of the SoW assembly showed superior heat spreading across the assembly in a checkerboard configuration of alternate hot (0.5 W/mm
²
) and cold (0.1 W/mm2) dielets with an average temperature of 82 °C & 78 °C respectively.