Hybrid bonding is becoming the preferred approach to making heterogeneous integration work, as the semiconductor industry shifts its focus from 2D scaling to 3D scaling. By stacking chiplets vertically in direct wafer-to-wafer bonds, chipmakers can leapfrog attainable interconnection pitch from 35µm in copper micro-bumps to 10µm or less. That reduces signal delay to negligible levels and enables smaller, thinner packages