1. What is PCB Trace Clearance?

Definition: Trace clearance is the minimum distance required between conductive elements on a PCB to prevent arcing and ensure proper insulation.

Purpose: Proper clearance prevents electrical breakdown, reduces crosstalk, and ensures safety compliance in high-voltage applications.

2. How Does the Calculator Work?

The calculator uses the standard IPC-2221 formula:

Where:

• Spacing — Minimum clearance between traces (mm)
• Vpeak — Peak voltage difference between conductors (volts)

Explanation: The formula accounts for both a base clearance (0.6mm) and additional spacing proportional to the voltage.

3. Importance of Proper Trace Clearance

Details: Adequate clearance prevents:

• Electrical arcing between conductors
• Dielectric breakdown
• Safety hazards in high-voltage circuits
• Manufacturing defects

4. Using the Calculator

Tips: Enter the peak voltage between adjacent traces. The calculator will determine the minimum recommended spacing.

5. Frequently Asked Questions (FAQ)

Q1: Is this formula valid for all PCB materials?
A: This is a general formula for standard FR4 material. Special materials may require different calculations.

Q2: How does altitude affect clearance requirements?
A: Higher altitudes may require greater clearances due to reduced air density. Consult IPC standards for altitude adjustments.

Q3: What about creepage vs clearance?
A: This calculator determines electrical clearance. Creepage (distance along surfaces) often requires greater spacing.

Q4: When should I use greater than calculated clearance?
A: Consider increased spacing for:

• High-reliability applications
• High-altitude operation
• Polluted environments

Q5: Are there regulatory standards for clearance?
A: Yes, refer to IPC-2221, IEC 60950, or UL standards for specific application requirements.