alt Hacker NewsGenerally, multi-chip-modules are for multiple die attached to (advanced) PCB backplanes, while CoWoS (Chip-on-Wafer-on-Substrate) and Foveros are using (passive) silicon backplanes. It radically increases bump and interconnect density.
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monocasa • today at 1:08 AM
I don't think chiplets require or even are even generally seen with silicon backplanes yet, otherwise you'd be leaving out stuff like AMD's CPUs.
And from there, stuff like the Vac 9000's packaging were very advanced for the time designs that I'd hesitate to call PCBs unless we're calling all organic packaging PCBs now.
The silicon backplanes are also soldered on (advanced) PCB backplanes, so they are just interposers.
I do not think that using various kinds of silicon bridges warrants a change in name. It should be fine to call any such product that uses multiple chips as a MCM (multi-chip module). Even for consumer CPUs, MCMs have already a long history, e.g. with AMD Bulldozer variants, or with the earlier Pentium and Athlon that had the L2 cache memory on a separate chip.
The word "chiplet" is relatively new and its appearance is justified for naming a chip whose purpose is to be a part of a MCM, instead of being packaged separately. A modern chiplet should be designed specifically for this purpose, because its I/O buffers need very different characteristics for driving the internal interfaces of the MCM, in comparison with driving interfaces on a normal PCB, i.e. they can be smaller and faster.