Stefan Mileschin

With transistor shrinks slowing and demand for HPC gear growing, as of late there has been an increased interest in chip solutions larger than the reticle size of a lithography machine – that is, chips bigger than the maximum size that a single chip can be produced. We've already seen efforts such as Cerebras' truly massive 1.2 trillion transistor wafer scale engine, and they aren't alone. As it turns out, TSMC and Broadcom have also been playing with the idea of oversized chips, and this week they've announced their plans to develop a supersized interposer to be used in Chip-on-Wafer-on-Substrate (CoWoS) packaging.

Overall, the proposed 1,700 mm² interposer is twice the size of TSMC's 858 mm² reticle limit. Of course, TSMC can't actually produce a single interposer this large all in one shot – that's what the reticle limit is all about – so instead the company is essentially stitching together multiple interposers, building them next to each other on a single wafer and then connecting them. The net result is that an oversized interposer can be made to function without violating reticle limits.

https://www.anandtech.com/show/15582...-than-reticles