CoWoS is an integrated process technology that attaches device silicon chips to a wafer through a chip on wafer (CoW) bonding process. The CoW chip is attached to the substrate (CoW-On-Substrate) to form the final component. By attaching the device silicon to the original thick wafer silicon before it finishes the fabrication process, manufacturing-induced warping is avoided. TSMC plans to offer CoWoS as a turnkey manufacturing service.
“Heterogeneous 3D ICs are one of the innovations enabling the industry’s move beyond Moore’s Law by stacking various technologies within a single device, including analog, logic and memory.”
Another point is that this test vehicle should really only be
classed as a 2.5D IC, because it involves a number of die being attached to a silicon interposer, which is in turn attached to the package substrate using Thru Silicon Via (TSV) technology. A true 3D IC involves die being stacked on top of other die (see also The challenges of 2.5D versus 3D).