1. What is a PCB Track Width Calculator?

Definition: This calculator determines the minimum width of a PCB trace needed to safely carry a specified current without exceeding a given temperature rise.

Purpose: It helps PCB designers ensure proper current carrying capacity while preventing excessive heating of traces.

2. How Does the Calculator Work?

The calculator uses the IPC-2221 formula:

Where:

• \( Width \) — Trace width (mils)
• \( I \) — Current (amps)
• \( \Delta T \) — Temperature rise (°C)
• \( thickness \) — Copper thickness (oz/ft²)
• \( k \) — Constant (0.048 for external, 0.024 for internal layers)

Explanation: The formula accounts for current, acceptable temperature rise, copper thickness, and whether the trace is on an external or internal layer.

3. Importance of Proper Trace Width

Details: Correct trace width prevents overheating, voltage drops, and potential PCB failure while optimizing board space usage.

4. Using the Calculator

Tips: Enter the current in amps, desired temperature rise (default 10°C), copper thickness (default 1 oz/ft²), and select layer type. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a safe temperature rise for PCB traces?
A: Typically 10-20°C is safe for most applications, but this depends on your specific design requirements.

Q2: Why different constants for internal/external layers?
A: External layers have better heat dissipation than internal layers, allowing them to carry more current for the same width.

Q3: What copper thickness should I use?
A: Standard PCBs use 1 oz/ft² (35 µm), but high-current designs may use 2 oz/ft² or more.

Q4: How accurate is this calculator?
A: It provides estimates based on IPC standards. For critical applications, consult detailed thermal analysis.

Q5: Does this account for high-frequency effects?
A: No, this is for DC/low-frequency current. High-frequency designs require additional considerations.