1. What is PCB Thermal Resistance?

Thermal resistance (θ) is a measure of a material's ability to resist heat flow. For PCBs, it's crucial for thermal management, determining how effectively heat can be conducted away from components.

2. How Does the Calculator Work?

The calculator uses the thermal resistance equation:

Where:

• \( \theta \) — Thermal resistance (K/W)
• \( L \) — Length of the material (m)
• \( k \) — Thermal conductivity (W/mK)
• \( A \) — Cross-sectional area (m²)

Explanation: The equation shows that thermal resistance increases with length and decreases with higher conductivity or larger cross-sectional area.

3. Importance of Thermal Resistance Calculation

Details: Accurate thermal resistance calculation is essential for proper heat dissipation in electronic designs, preventing component overheating and ensuring reliability.

4. Using the Calculator

Tips: Enter length in meters, thermal conductivity in W/mK, and cross-sectional area in m². All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's typical thermal conductivity for PCB materials?
A: FR4 is about 0.3 W/mK, while metal-core PCBs can be much higher (e.g., aluminum ~200 W/mK).

Q2: How does via count affect thermal resistance?
A: Additional vias can significantly reduce thermal resistance by providing parallel heat paths.

Q3: What's a good thermal resistance value?
A: Lower is better, but depends on application. Power electronics might need <1 K/W, while consumer devices can tolerate higher.

Q4: Does this account for convection/radiation?
A: No, this calculates conduction resistance only. Full thermal analysis requires additional calculations.

Q5: How accurate is this for multilayer PCBs?
A: For complex multilayer boards, more sophisticated thermal modeling is recommended.