1. What is a PCB Max Current Calculator?

Definition: This calculator estimates the maximum current a PCB trace can handle based on temperature rise, copper area, and a material constant.

Purpose: It helps electrical engineers and PCB designers ensure safe current carrying capacity in their designs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I_{max} \) — Maximum current (amps)
• \( \Delta T \) — Temperature rise (°C)
• \( A \) — Copper area (m²)
• \( k \) — Material constant (typically 0.048 for external layers)

Explanation: The formula accounts for how much current can flow before causing a specified temperature rise in the PCB trace.

3. Importance of PCB Current Calculation

Details: Proper current estimation prevents overheating, ensures reliability, and maintains signal integrity in electronic circuits.

4. Using the Calculator

Tips: Enter the desired temperature rise, copper area (width × thickness), and material constant (default 0.048). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical temperature rise limit?
A: Common limits are 10-20°C for general designs, up to 30°C for high-reliability applications.

Q2: How do I calculate copper area?
A: Multiply trace width (in meters) by thickness (typically 35µm or 1oz/ft² = 0.000035m).

Q3: When would I change the constant value?
A: Use 0.024 for internal layers or different values based on specific PCB material properties.

Q4: Does this account for ambient temperature?
A: No, ΔT is the temperature rise above ambient. Consider your operating environment.

Q5: What about multiple parallel traces?
A: For parallel traces, sum their areas but consider current crowding effects at connections.