Segment
Advanced packaging: the step that became the bottleneck
Packaging used to be the cheap step at the end: put the die in a plastic body, attach some leads, ship it. For high-performance parts it is now a set of precision processes that determine whether a product can exist at all, and it has been the binding constraint on AI accelerator supply more often than wafer capacity has.
In one sentence
Advanced packaging is the set of techniques that connect multiple dies, and stacks of memory, within a single package at densities far beyond conventional wire-bonded or flip-chip assembly.
Two pressures produced it. The first is that a die large enough to hold a whole design yields badly, so designs are split into smaller pieces that must then be reconnected with something close to on-chip bandwidth. The second is that memory has to sit within millimetres of the processor to deliver the bandwidth modern workloads need, which means it has to be inside the package.
The techniques differ in how the connection is made. A silicon interposer routes thousands of wires between dies mounted side by side. A hybrid bond joins two dies face to face with direct copper contact and no solder at all. Substrates carry the whole assembly out to the board. Each is a distinct capability with its own capacity limits and its own supplier base.
This is where the AI hardware queue actually forms. Wafer capacity for accelerators has generally been available; interposer and assembly capacity has not, and it takes years to add because it is specialised equipment operated by a small number of firms.
How this breaks down
Split by how the dies are connected to each other and to the outside world.
- Bonding equipmentDie bonders, flip-chip attach and hybrid bonders — the tools whose throughput sets packaging capacity.Definition page
- ChipletsSplitting a design into smaller dies to escape the yield penalty, and the interfaces that make it work.Definition page
- Interposers and 2.5DThe silicon slab that carries thousands of wires between a processor and its memory stacks.Definition pageChokepoint
- Hybrid bondingDirect copper-to-copper contact at micron pitch, and why it is the enabler for true 3D stacking.Definition pageChokepoint
- Package substratesThe build-up laminate every chip sits on, and the single-source film it is made from.Breaks down into: Build-up film · Copper foil and laminate2 pages belowChokepoint
What this depends on
1 of these is marked as a chokepoint: a handful of qualified suppliers, a multi-year lead time, or a single geography.
- Supply chainChokepoint
Assembly and test capacity
Most of this work is performed by contract providers rather than by the companies whose names are on the parts. When their advanced lines are full, products with wafers still do not ship.
OSAT - Technology
Known-good-die test
One untested die ruins every good die assembled around it, and the value destroyed rises with each part already attached.
Metrology and test
What depends on this
Other pages in this map that name Advanced packaging as something they cannot do without.
- Artificial intelligence · AI computeAI acceleratorsThe accelerator die and its memory stacks have to be joined on an interposer before the part exists at all. Packaging capacity, not wafer capacity, has repeatedly been the binding constraint.
- Semiconductors · Foundry and capacityFoundry vs IDMFor high-end products the foundry relationship now extends through packaging, which is separately constrained.
- Artificial intelligence · AI networkingOptical interconnectMoving the optical engines next to the switch die turns a module into a packaging problem, sharing substrates and assembly lines with the rest of the advanced-packaging queue.
- Electric vehicles · PowertrainSilicon carbide electronicsFast switching creates electrical noise and thermal stress; the module packaging and gate drive are as important as the die.
- Artificial intelligence · AI networkingSwitch siliconLarge switch dies with very high input-output counts increasingly need 2.5D packaging of their own.
Companies across Advanced packaging
Every company named on a step below this page, ordered by how many of those steps it appears at. Compiled from the pages themselves rather than written separately, so the two cannot disagree. Not a ranking and not a recommendation.
- Shinko Electric IndustriesPrivate3 steps
- BesiNetherlands2 steps
- EV GroupPrivate2 steps
- SUSS MicroTecGermany2 steps
25 more companies appear at a single step each; they are named on the pages for those steps.
How these pages are written
Each page explains one technology in plain language, states what it depends on, and names companies by what they supply at that step. Company roles are described qualitatively and deliberately carry no market shares, revenue figures or rankings — those change faster than an explainer can, and a stale number is worse than none. Ticker links point at company pages on this site and are provided for reference only.
Nothing here is investment advice, a recommendation, or a forecast. A company named on a page about a technology is not thereby a good investment, and the chokepoints described are structural facts about supply chains rather than predictions about prices. Technology moves; where a page describes something as unresolved or in development, that was true when it was written.