1. What is PCB Trace Resistance?

PCB trace resistance is the electrical resistance of a copper trace on a printed circuit board. It depends on the resistivity of copper, trace dimensions (length, width, and thickness), and temperature.

2. How Does the Calculator Work?

The calculator uses the PCB trace resistance formula:

Where:

• \( \rho \) — Resistivity of the material (Ω·m)
• \( Length \) — Length of the trace (m)
• \( Width \) — Width of the trace (m)
• \( Thickness \) — Thickness of the trace (m)

Explanation: The resistance increases with longer traces and decreases with wider or thicker traces. Copper's resistivity is typically 1.68×10⁻⁸ Ω·m at 20°C.

3. Importance of Trace Resistance Calculation

Details: Calculating trace resistance is essential for proper PCB design, ensuring signal integrity, power delivery, and preventing excessive voltage drops or heating.

4. Using the Calculator

Tips: Enter resistivity in Ω·m (1.68×10⁻⁸ for copper), dimensions in meters. Default values are provided for standard 1 oz copper (35µm thickness).

5. Frequently Asked Questions (FAQ)

Q1: What's the resistivity of copper?
A: Pure copper at 20°C has ρ ≈ 1.68×10⁻⁸ Ω·m. This increases with temperature (about 0.4% per °C).

Q2: How does copper weight affect thickness?
A: 1 oz copper = 35µm (0.035mm), 2 oz = 70µm, etc. This refers to weight per square foot.

Q3: Why does resistance matter in PCB design?
A: High resistance traces can cause voltage drops, power loss, heating, and signal integrity issues.

Q4: How does temperature affect resistance?
A: Resistance increases with temperature. For precise calculations, adjust ρ for operating temperature.

Q5: What about skin effect at high frequencies?
A: At high frequencies, current flows near the surface, effectively reducing the conductive area. This calculator provides DC resistance.