An electrical interface between chips and the package. Silicon interposers are also used to stack 3D chips using through-silicon vias (TSVs). They are widely used to combine new functions with old ones; for example, AI accelerators are increasingly being added to CPUs. See
via.
Integrating Chiplets
Silicon interposers (bottom) are widely used to combine multiple chiplets onto a single package (see
MCM).
(Image courtesy of Arteris.)