1. What is PCB Voltage Clearance?

PCB voltage clearance refers to the minimum distance required between two conductive elements on a printed circuit board to prevent electrical breakdown or arcing at a given voltage. The IPC-2221 standard provides guidelines for calculating these clearances based on voltage and environmental factors.

2. How Does the Calculator Work?

The calculator uses the IPC-2221 formula:

Where:

• \( Voltage \) — Potential difference between conductors (V)
• \( Factor \) — Multiplier based on environment and coating (mm/V)

Standard Factors:

• Internal, uncoated: 0.001 mm/V
• Internal, coated: 0.0005 mm/V
• External, uncoated: 0.005 mm/V
• External, coated: 0.0025 mm/V

3. Importance of Proper Clearance

Details: Adequate clearance prevents electrical arcing, short circuits, and potential fire hazards. It's critical for reliability and safety in both low and high voltage applications.

4. Using the Calculator

Tips: Enter the maximum working voltage between conductors, select the environment (internal/external) and whether the board has conformal coating. The calculator will determine the minimum required clearance.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between internal and external environments?
A: Internal refers to enclosed, protected environments with controlled humidity. External means exposed to atmospheric pressure, pollution, or condensation.

Q2: How does conformal coating affect clearance?
A: Proper conformal coating can reduce required clearances by 50% as it provides additional insulation.

Q3: Are there additional considerations for high voltage?
A: For voltages above 500V, additional derating factors may apply. Consult IPC-2221 for complete guidelines.

Q4: What about creepage distance?
A: Creepage (along surfaces) often requires greater distances than clearance (through air). This calculator provides clearance only.

Q5: Do these values meet safety standards?
A: These are general design guidelines. For safety-critical applications, consult relevant safety standards (UL, IEC, etc.).