---
title: "Circuit Board"
industry: "Computer, Electronic and Optical Product Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:CIRCUIT_BOARD"
  data_integrity_hash: "36c99bcee8af41aa44b072316b6ffb81"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:CIRCUIT_BOARD"
  data_source_uri: "https://cnfx.com/llms/industry/computer-electronic-and-optical-product-manufacturing/product/circuit-board.md"
  official_resource_url: "https://cnfx.com/industry/computer-electronic-and-optical-product-manufacturing/product/circuit-board"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "0-125°C ambient temperature, 0-100% relative humidity (non-condensing), 0-3000 m altitude"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 4
    unit: "substrate"
    consequence: "Thermal expansion coefficient mismatch between copper (17 ppm/°C) and FR-4 substrate (13-16 ppm/°C) causing mechanical stress, electrochemical migration at &gt;85% RH with &gt;5V bias, glass transition phase change at Tg"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Electrochemical migration due to ionic contamination (Na+, K+, Cl- ions) &gt;10 μg/cm² with &gt;85% RH and &gt;5V potential difference"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Conformal coating application (25-75 μm acrylic/polyurethane), cleanliness control to &lt;1.56 μg/cm² NaCl equivalence per IPC-5701"
  - node_2:
      trigger: "Thermal cycling stress (-40°C to +125°C, 1000 cycles) with ΔT=165°C"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Adoption of high-Tg materials (Tg&gt;170°C), use of curved trace routing (135° angles), implementation of strain relief cutouts in board outline"
bom_nodes:
  copper-traces:
    type: "component"
    urn: "URN:CNFX:ME:COPPER_TRACES"
    interface_type: "physical-logic-coupled"
  solder-mask:
    type: "component"
    urn: "URN:CNFX:ME:SOLDER_MASK"
    interface_type: "physical-logic-coupled"
  silkscreen:
    type: "component"
    urn: "URN:CNFX:ME:SILKSCREEN"
    interface_type: "physical-logic-coupled"
  vias:
    type: "component"
    urn: "URN:CNFX:ME:VIAS"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
url: "https://cnfx.com/llms/industry/computer-electronic-and-optical-product-manufacturing/product/circuit-board.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "51ad93420ce21f6bf793765c08232bcec5b4f10c1f6d5a44a6e35f87b6e78e3c"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Circuit Board

## 1. Technical Definition
A physical platform that mechanically supports and electrically connects electronic components using conductive tracks, pads, and other features etched from copper sheets laminated onto a non-conductive substrate.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **0-125°C ambient temperature, 0-100% relative humidity (non-condensing), 0-3000 m altitude**. Failure boundary: **Glass transition temperature (Tg) of FR-4 substrate at 130-140°C, copper trace delamination at 288°C (lead-free solder reflow temperature), dielectric breakdown at 500 V/mil (19.7 kV/mm) for FR-4**, Mechanism: **Thermal expansion coefficient mismatch between copper (17 ppm/°C) and FR-4 substrate (13-16 ppm/°C) causing mechanical stress, electrochemical migration at &gt;85% RH with &gt;5V bias, glass transition phase change at Tg**.

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Electrochemical migration due to ionic contamination (Na+, K+, Cl- ions) &gt;10 μg/cm² with &gt;85% RH and &gt;5V potential difference | 8 | Conductive anodic filament growth between adjacent traces causing short circuit | Conformal coating application (25-75 μm acrylic/polyurethane), cleanliness control to &lt;1.56 μg/cm² NaCl equivalence per IPC-5701 |
| Thermal cycling stress (-40°C to +125°C, 1000 cycles) with ΔT=165°C | 8 | Copper trace fatigue fracture at 90° bend radius due to accumulated plastic strain exceeding 0.3% | Adoption of high-Tg materials (Tg&gt;170°C), use of curved trace routing (135° angles), implementation of strain relief cutouts in board outline |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| spec | Config-dependent | mm | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Pick-and-Place Machine**, **Reflow Oven**, **Automated Optical Inspection System**  
**Downstream Applications**: Desktop Computers, Smartphones, Medical Imaging Devices  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What are the advantages of using FR-4 material in circuit boards?
**A**: FR-4 epoxy laminate offers excellent flame retardancy, mechanical strength, and electrical insulation, making it ideal for reliable and durable circuit boards in electronic applications.

### Q: How do vias improve circuit board performance?
**A**: Vias create electrical connections between different layers of a multi-layer PCB, enabling compact designs, reduced signal interference, and enhanced routing flexibility for complex electronic circuits.

### Q: What is the purpose of solder mask on a circuit board?
**A**: Solder mask protects copper traces from oxidation, prevents solder bridges during assembly, and provides insulation, ensuring long-term reliability and preventing short circuits in electronic devices.

## 6. Manufacturing Compliance

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### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Circuit Board](https://cnfx.com/industry/computer-electronic-and-optical-product-manufacturing/product/circuit-board)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **4** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: CIRCUIT_BOARD | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 3ac73729
