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 while keeping the temperature rise within acceptable limits.

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 width needed to dissipate heat effectively based on current, temperature rise, and copper thickness.

3. Importance of Trace Width Calculation

Details: Proper trace width ensures reliable PCB operation, prevents overheating, and maintains signal integrity in electronic circuits.

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 can dissipate heat better (k=0.048) while internal traces (k=0.024) require more width for the same current.

Q2: What's a typical temperature rise value?
A: 10°C is common, but higher values (20-30°C) may be acceptable for some applications.

Q3: How does copper thickness affect the result?
A: Thicker copper (2 oz/ft²) allows narrower traces for the same current, while thinner copper requires wider traces.

Q4: What if my trace needs to carry high current?
A: Consider using multiple layers, thicker copper, or adding solder to increase current capacity.

Q5: Does this include safety margins?
A: No, consider adding 10-20% to the calculated width for design margin.