VR2-0376
① SA Source
- Source: 開啟完整 SA 文章
- Section:
PCB Materials Upgrade and Area Growth - Line hint:
473
Context Before
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).
Quartz cloth is the next generation material that replaces the glass fiber cloth materials as the reinforcing layer, pushing dielectric constant even lower. Besides lower dielectric constant, quartz cloth also has the benefits of being stronger, more temperature resistance, and having a lower CTE. 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.
Evidence
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
Context After
Source: Nvidia VR NVL72 Component BoM and Power Budget Model ↗
② Atomic Claim
在 VR NVL72 中，Quartz 最初用於 Orchid board 與 midplane，以讓最長距離的 PCIe Gen 6 signal 通過這兩塊 boards 時，insertion loss 盡可能低。
- Epistemic Mode:
ASSERTED - Mapping Status:
PARTIAL
③ Semantic Frame
{
"attribute": "UNSPECIFIED_ATTRIBUTE",
"context_nodes": [
{
"id": "04_knowledge_base/NVIDIA Orchid Board",
"label": "Orchid board"
},
{
"id": "04_knowledge_base/Midplane",
"label": "midplane"
},
{
"id": "04_knowledge_base/PCIe",
"label": "PCIe Gen 6"
},
{
"id": "04_knowledge_base/Insertion loss",
"label": "insertion loss"
}
],
"entity": {
"id": "04_knowledge_base/VR NVL72",
"label": "VR NVL72"
},
"frame_type": "ATTRIBUTE",
"qualifiers": {
"condition_text": null,
"numeric_mentions": [
"6 s"
],
"temporal_mentions": []
},
"value": {
"numeric_mentions": [
"6 s"
],
"value_text": "在 VR NVL72 中，Quartz 最初用於 Orchid board 與 midplane，以讓最長距離的 PCIe Gen 6 signal 通過這兩塊 boards 時，insertion loss 盡可能低。"
}
}④ Canonical Entity Mapping
| Role | Surface Label | Canonical Target |
|---|---|---|
| entity | VR NVL72 | 04_knowledge_base/VR NVL72 |
| context_0 | Orchid board | 04_knowledge_base/NVIDIA Orchid Board |
| context_1 | midplane | Midplane |
| context_2 | PCIe Gen 6 | PCIe |
| context_3 | insertion loss | 04_knowledge_base/Insertion loss |
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。