VR2-0321
① SA Source
- Source: 開啟完整 SA 文章
- Section:
PCB vs Flyover Cables - Line hint:
431
Context Before
Source: DesignCon, Circuit Foil Luxembourg
Evidence
At higher frequencies, the signal traveling through the copper crowds toward the surface of the trace, which is known as the skin effect
Context After
Dielectric loss is driven by the energy absorption nature of the dielectric materials. Dielectric materials, resins and glass fiber cloth, provide insulation and mechanical reinforcement function for the PCB traces. At high frequency, high-speed signal doesn’t simply travel through the copper traces, the signal traves as an electromagnetic wave with electric field extending into the dielectric materials. As the signal propagates, the dielectric absorbs a portion of the energy and dissipates as heat, contributing to insertion loss. Dielectric loss scales with frequency, hence dielectric loss is a dominant limiter of signal performance of long reach PCB traces.
Geometry loss describes the insertion loss incurred from abrupt structures of the PCB traces. Real PCB channels include many abrupt structures, such as vias and layer swaps. These are like bumps in a highway, and signals could reflect backward and be interrupted increasing insertion loss.
② Atomic Claim
頻率越高，signal 通過 copper 時越集中於 trace 表面，此現象稱為 skin effect。
- Epistemic Mode:
ASSERTED - Mapping Status:
PARTIAL
③ Semantic Frame
{
"attribute": "UNSPECIFIED_ATTRIBUTE",
"context_nodes": [],
"entity": {
"id": "04_knowledge_base/Copper",
"label": "copper"
},
"frame_type": "ATTRIBUTE",
"qualifiers": {
"condition_text": null,
"numeric_mentions": [],
"temporal_mentions": []
},
"value": {
"numeric_mentions": [],
"value_text": "頻率越高，signal 通過 copper 時越集中於 trace 表面，此現象稱為 skin effect。"
}
}④ Canonical Entity Mapping
| Role | Surface Label | Canonical Target |
|---|---|---|
| entity | copper | Copper |
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。