silicon interposer
Beginner
A thin slice of silicon that works like a tiny circuit board. It wires several chips together side by side.
Novice
A slice of silicon with very fine wiring but no transistors. Several chips and memory stacks sit side by side on top of it, and it connects them to each other and, through vertical holes filled with metal, to the package below. This arrangement is called 2.5D packaging.
Expert
Passive silicon carrying micrometer-scale routing between dies, at far higher density than an organic package substrate, with through-silicon vias down to the substrate. It can itself exceed one reticle, and its yield, cost and warpage become part of the product’s risk.
Explained in AI accelerators and datacenter (Industries).