# NVLink copper spine / backplane cartridges

Part ID: 3.10 · Layer 3 (Networking & interconnect)

The copper cable assemblies and backplane cartridges that physically wire the scale-up fabric together inside a rack, most visible in Nvidia's NVL72 architecture.

NVLink copper spine and backplane cartridges are the physical layer under the scale-up fabric of 3.01, wiring GPU compute trays to NVLink switch trays inside a rack — the taxonomy notes roughly 5,000 copper cables in an NVL72-class rack. That cable count is itself the reason the industry is evaluating co-packaged optics (3.08) as a replacement at the next speed generation: as per-GPU bandwidth rises, all-copper backplanes start running into reach and density limits that pushing more copper doesn't solve. Several connector and cable assembly makers supply this content, generally under reference-design partner arrangements with the rack architect rather than as a fully open market. An investor should watch this layer as a bellwether for the copper-to-optical transition inside the rack: continued growth in cable count per rack favors incumbent copper suppliers, while an early shift to CPO would cap that growth sooner than volume trends alone would suggest.

**AI delta:** Larger scale-up domains push cable count per rack higher, up to the point where copper's reach and density limits at the highest speeds make an optical alternative necessary.

## Companies

| Company | Role | Confidence | Ownership | Ticker | Note |
|---|---|---|---|---|---|
| Amphenol | manufacturer | reported | public | APH |  |
| Bizlink | manufacturer | reported | public | 3665.TW |  |
| Foxconn Interconnect | manufacturer | reported | public | 6088.HK |  |
| Luxshare | manufacturer | reported | public | 002475.SZ |  |
| TE Connectivity | manufacturer | reported | public | TEL |  |

Confidence tags: disclosed = company/filing statement; reported = trade press or partner list; inferred = taxonomy lead.