# Who does AT&S pay? Who are its key suppliers?
Canonical: https://valuechain.wiki/at-s · Facet: suppliers · Updated: 2026-07-12T08:22:44.684+00:00 · Source: ValueChain.wiki (cited money-flow graph)

**Citable summary**: AT&S's confirmed suppliers/cost counterparties include Ajinomoto, Resonac plus 1 undisclosed/aggregate relationship. Per the valuechain.wiki graph: 3 cost edges, backed by 3 dated sources, 0 of them primary filings (as of 2026-07-12).

### Ajinomoto (mid)  → /ajinomoto.md
- note: Sources interlayer dielectric (ABF) near-exclusively from Ajinomoto — Ajinomoto Build-up Film is an essential, effectively monopolized material for high-end substrates, so this single-material dependence is the biggest supply-chain bottleneck and a structural risk.
- [confirms] TradingKey (EN, research, published 2026-01-01) https://www.tradingkey.com/analysis/stocks/us-stocks/261783966-abf-ajinomoto-nvidia-ai-supply-chain-tradingkey: "Sources interlayer dielectric (ABF) from Ajinomoto (near sole source)."

### Resonac (mid)  → /resonac.md
- note: Buys ABF and substrate materials from Resonac — a key advanced-packaging material source, where securing supply is the precondition for running the new capacity.
- [confirms] AT&S (EN, ir, published 2025-05-01) https://ams.at-s.com/: "Buys ABF and substrate materials from Resonac."
- [confirms] IMR (EN, analysis, published 2025-01-01) https://www.intelmarketresearch.com/global-package-substrates-forecast-market-27111: "Buys ABF and substrate materials from Resonac."

### 동박·빌드업 소재 (비공개) (low)
- note: Sources and invests in materials and R&D for substrate manufacture (undisclosed) — material purity and fine-line technology anchor high-end substrate competitiveness.
- [confirms] AT&S (EN, ir, published 2025-05-01) https://ams.at-s.com/: "Materials and R&D (undisclosed)."

Reverse side: https://valuechain.wiki/at-s/customers.md · Ripple: https://valuechain.wiki/at-s/ripple.md

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Full node: https://valuechain.wiki/at-s.md · JSON: https://valuechain.wiki/at-s.json