1. What is PCB Trace Clearance?

PCB trace clearance refers to the minimum distance required between conductive elements on a printed circuit board to prevent electrical breakdown or arcing between conductors. Proper clearance is critical for safety and reliability of electronic circuits.

2. How Does the Calculator Work?

The calculator uses the basic clearance formula:

Where:

• \( Voltage \) — Potential difference between conductors (V)
• \( Dielectric\ Strength \) — Material's breakdown voltage per unit thickness (V/mm)

Explanation: The formula calculates the minimum distance needed between conductors to prevent dielectric breakdown at a given voltage.

3. Importance of Proper Clearance

Details: Adequate clearance prevents electrical arcing, short circuits, and potential fire hazards. It's particularly important in high-voltage applications and safety-critical designs.

4. Using the Calculator

Tips: Enter the maximum working voltage and the dielectric strength of your PCB material. Typical FR4 dielectric strength is about 20kV/mm, but consult your material specifications for exact values.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect trace clearance requirements?
A: Voltage level, altitude (air pressure), pollution degree, material properties, and safety standards all influence clearance requirements.

Q2: Is this calculation sufficient for safety certifications?
A: For certified products, always follow applicable standards (IPC, UL, IEC) which may require larger clearances than the basic calculation.

Q3: How does altitude affect clearance?
A: At higher altitudes, reduced air density lowers breakdown voltage, requiring increased clearances (typically +100% per 5000m altitude).

Q4: What about creepage distance?
A: Creepage (distance along surfaces) often requires greater spacing than clearance (straight-line distance through air).

Q5: Typical dielectric strength values?
A: FR4: ~20kV/mm, Air: ~3kV/mm, Polyimide: ~25kV/mm. Always verify with your specific material data sheet.