1. What is a PCB Trace Width Calculator?

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

Purpose: It helps PCB designers ensure proper current carrying capacity and prevent overheating in electronic circuits.

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 traces)

Explanation: The formula calculates the minimum trace width needed to dissipate heat effectively for a given current.

3. Importance of Proper Trace Width

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

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between external and internal traces?
A: External traces (on outer layers) dissipate heat better than internal traces, hence the different k constants.

Q2: What temperature rise should I use?
A: 10°C is common, but higher values (20-30°C) may be used for high-current applications.

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

Q4: Does this account for high-frequency effects?
A: No, this is for DC/low-frequency currents. High-frequency designs need additional considerations.

Q5: How accurate is this calculator?
A: It follows IPC standards but consult your PCB manufacturer for specific requirements.