VR2-0375
① SA Source
- Source: 開啟完整 SA 文章
- Section:
PCB Materials Upgrade and Area Growth - Line hint:
471
Context Before
For the power layers, the additional layers in Strata compared to Blackwell are mostly power layers to accommodate more power going into the GPU. By adding more dedicated power layers, cross talk is reduced as power layers and signal layers are separated. Power layer copper foils are much thicker to insulate the current travelling through it.
The glass fiber cloth upgrade aims to reduce the dielectric constant of CCL. Beside glass fiber cloth, resin is also a key factor contributing to dielectric constant. To achieve a desirable dielectric constant, the CCL makers have their unique recipes to their formulation of the two dielectric materials in the CCL. Currently, debate around the CCL spec is around the adoption of Quartz cloth (Q glass).
Evidence
On the other hand, the cost is multiples higher than that of the highest-grade glass fiber cloth and is much harder to process at the PCB manufacturing level, leading to worse yield
Context After
Within VR NVL72, Quartz is initially adopted for the Orchid board and the midplane to allow the longest distance PCIe Gen 6 signal traveling through these two boards with as little insertion loss as possible. However, given the cost of the Quartz cloth and the difficulty in Q cloth processing, Nvidia is currently exploring the option of downgrading back to glass fiber cloth. The final decision is pending on the signal performance with the downgraded glass fiber cloth.
② Atomic Claim
Quartz cloth 在 PCB 製造端也更難加工，因此良率較差。
- Epistemic Mode:
ASSERTED - Mapping Status:
COMPLETE
③ Semantic Frame
{
"attribute": "YIELD",
"context_nodes": [
{
"id": "04_knowledge_base/PCB",
"label": "PCB"
}
],
"entity": {
"id": "04_knowledge_base/Quartz cloth",
"label": "Quartz cloth"
},
"frame_type": "ATTRIBUTE",
"qualifiers": {
"condition_text": null,
"numeric_mentions": [],
"temporal_mentions": []
},
"value": {
"numeric_mentions": [],
"value_text": "Quartz cloth 在 PCB 製造端也更難加工，因此良率較差。"
}
}④ Canonical Entity Mapping
| Role | Surface Label | Canonical Target |
|---|---|---|
| entity | Quartz cloth | 04_knowledge_base/Quartz cloth |
| context_0 | PCB | PCB |
⑤ Human Review
請在 Properties 逐項確認：
- 原文 → Atomic Claim 是否忠實
- Atomic Claim → Semantic Frame 是否忠實
- Canonical Entity mapping 是否正確
- Epistemic mode 是否保留原文語氣
- 最後選擇
review_action
Review state
Markdown 內文不是正式 approval。只有 Apply bridge 寫入的 Decision Ledger event 才是正式決策。