- Advanced packaging
- The set of manufacturing techniques that integrate several separately fabricated dies, memory, and a substrate into a single finished package that behaves electrically like one component. For high-end accelerators it is a distinct, capacity-constrained step downstream of wafer fabrication.
- Allocation
- The commercial division of fixed, scarce packaging and substrate capacity among competing buyers, decided by long-term commitments, prepayments, and priority relationships made years ahead. When demand exceeds capacity, allocation, rather than aggregate capacity, determines who receives accelerators.
- Heterogeneous integration
- The practice of combining multiple dies, often made on different processes, into one package rather than building a single monolithic die. It exists because a die large enough to hold both the logic and the memory bandwidth a large model needs cannot be manufactured at acceptable yield.
- High-bandwidth memory
- Memory built as a vertical stack of DRAM dies connected by through-silicon vias, exposing an extremely wide interface to deliver very high bandwidth. It is made by a small number of suppliers and must arrive in matched quantities alongside the logic die.
- Side-by-side interposer integration
- An advanced-packaging approach that places the logic die and its memory stacks flat on a shared silicon interposer, connecting them horizontally. It is the most widely deployed method for high-end accelerators and the capacity most often described as sold out.
- Silicon interposer
- A passive slab of chip-grade material that sits beneath the logic die and memory stacks, providing wiring fine and dense enough to carry the very wide, high-bandwidth connections between them, denser than any organic substrate can achieve.
- Substrate
- The laminated organic board beneath the interposer that fans connections out from the interposer's fine pitch to a pitch a circuit board can attach to. High-end accelerators require many-layered, ultra-fine substrates made by a few specialist suppliers.
- Vertical die stacking
- An integration family that bonds dies directly on top of one another, connecting them face to face through short, dense links. It can be done by fusing dies together or by tiling active dies on a base die, and it uses different tools and facilities than interposer integration.