1. What is the PCB Trace Width Calculation?

The PCB trace width calculation determines the minimum width needed for a copper trace to carry a specified current without exceeding a given temperature rise, based on IPC-2221 standards.

2. How Does the Calculator Work?

The calculator uses the IPC-2221 approximation:

Where:

• \( I \) — Current in amps
• \( k \) — 0.024 (external traces) or 0.048 (internal traces)
• \( \Delta T \) — Temperature rise in °C
• thickness factor — Copper weight (1 oz/ft² = 1.37 mil thickness)

Explanation: The equation accounts for the relationship between current carrying capacity, temperature rise, and copper cross-sectional area.

3. Importance of Proper Trace Width

Details: Correct trace width is essential for preventing overheating, ensuring reliability, and meeting safety standards in PCB design.

4. Using the Calculator

Tips: Enter current in amps, desired temperature rise in °C, select trace location (internal/external), and copper thickness. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between internal and external traces?
A: External traces have better heat dissipation (k=0.024) while internal traces (k=0.048) require wider widths for the same current.

Q2: What's a typical temperature rise limit?
A: Common limits are 10°C for general use, 20°C for power circuits, but depends on application requirements.

Q3: How does copper thickness affect the calculation?
A: Thicker copper (2 oz vs 1 oz) allows narrower traces for the same current, as it increases cross-sectional area.

Q4: Are there limitations to this calculation?
A: This is an approximation. For high-current or high-frequency applications, more detailed analysis may be needed.

Q5: How does ambient temperature affect this?
A: The ΔT is temperature rise above ambient. Higher ambient temperatures may require more conservative calculations.