{
 "id": "4.05",
 "slug": "high-layer-count-pcbs-hdi-backdrilled",
 "url": "/parts/servers-racks-and-integration/high-layer-count-pcbs-hdi-backdrilled",
 "name": "High-layer-count PCBs",
 "qualifiers": "HDI, backdrilled, 20–40 layers",
 "layer": {
  "id": 4,
  "name": "Servers, racks & integration"
 },
 "parent_id": null,
 "children": [],
 "summary": "The bare printed circuit boards themselves — high-density interconnect, backdrilled, 20 to 40 copper layers — that GPU and switch trays are built on.",
 "description_md": "This is the physical board substrate beneath the baseboards and switch trays (4.03, 4.04): a laminate stack of 20 to 40 signal and power layers, built with HDI microvias and backdrilling to keep high-speed signal integrity across the board. It sits downstream of the laminate and copper-foil suppliers (4.06) and upstream of everything that gets populated onto it. AI boards push layer count and manufacturing precision well past a standard server motherboard because scale-up interconnect, high pin-count sockets and dense power delivery all need more routing layers and tighter tolerances than a general-purpose board. That raises both the capital intensity of the fabrication step and the qualification burden, since a board with dozens of layers has far more opportunities for a manufacturing defect to show up only under load. For investors, this is a capacity-constrained, capital-heavy tier of the supply chain: the fabricators that can reliably hit the highest layer counts at volume are a shorter list than the board designers who spec them, and that gap tends to widen, not narrow, with each new rack generation.",
 "ai_delta": "AI boards need far more routing layers and tighter fabrication tolerances than a standard server motherboard, because dense scale-up interconnect and high-pin-count sockets have to be routed across the same board.",
 "bottleneck_status": null,
 "scale_tiers": [
  "enterprise",
  "hyperscale_building",
  "ai_campus",
  "gw_class"
 ],
 "density_modes": [
  "any"
 ],
 "scale_notes": "layer count and fabrication precision scale with board complexity rather than data center size, so the highest-layer-count boards appear wherever the highest-end GPU trays are built, at any deployment scale.",
 "flow": [
  "compute",
  "power"
 ],
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   "name": "AT&S",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "ATS.VI",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "compeq",
   "name": "Compeq",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
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   "product_note": null,
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   "source_url": null
  },
  {
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   "name": "Dongshan",
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   "confidence": "inferred",
   "ownership_type": "public",
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   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "gold-circuit-gce",
   "name": "Gold Circuit GCE",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
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   "product_note": null,
   "note": null,
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  },
  {
   "company_id": "ibiden",
   "name": "Ibiden",
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   "ticker": "4062.T",
   "product_note": null,
   "note": null,
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   "company_id": "isu-petasys",
   "name": "ISU Petasys",
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   "product_note": null,
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  },
  {
   "company_id": "kingboard",
   "name": "Kingboard",
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   "note": null,
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  },
  {
   "company_id": "nan-ya-pcb",
   "name": "Nan Ya PCB",
   "role": "manufacturer",
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   "note": null,
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  },
  {
   "company_id": "shennan",
   "name": "Shennan",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "002916.SZ",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "tripod",
   "name": "Tripod",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
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   "product_note": null,
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  },
  {
   "company_id": "ttm",
   "name": "TTM",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "TTMI",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "unimicron",
   "name": "Unimicron",
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   "ticker": "3037.TW",
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   "note": null,
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  },
  {
   "company_id": "victory-giant",
   "name": "Victory Giant",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
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   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "wus",
   "name": "WUS",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "002463.SZ",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "zhen-ding",
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   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
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}