Process Considerations for Defluxing Ultra-Fine Pitch Die on CoWs

Heterogeneous integration has become one of the most important approaches in the semiconductor technology world. The process nodes are constantly shrinking from 16nm to 5nm and lower, with CMOS component speeds continuously increasing.  This is equivalent to integrating twice the number of components in the same amount of space every 18-24 months.

CoW (Chip on Wafer) is the next generation of CoS (Chip on Substrate) that first combines the chips to the interposer, adds wafer-level molding, and finally, they are connected to the flip chip (FC) substrate. This technology makes a better physical structure for accommodating very large die and larger overall interposer dimensions.