Six Steps to Design Your Own Heat Sink

1. Determine the maximum allowed thermal resistance (θ_max); 2. Determine the maximum space (width, length, height) available for the heat sink, and the airflow speed in your system (0 if there is only natural convection); 3. Calculate the thermal resistance (θ_SA) a heat sink can achieve within that size; 4. If θ_SA>θ_max, you need to either increase the heat sink size or the airflow speed, or change the power and temperature parameters so that θ_max is higher. You may also try to use a more conductive mateiral such as pure aluminum and copper. 5. If θ_SA<θ_max, congratulations, you got a solution. But you may want to make it smaller. You can repeat steps 3-5 to find a smaller size that still satisfies θ_SA<θ_max, but make sure you build in some margins to improve the robustness of your design; 6. Optimize the heat sink, add a thermal interface material, add mounting hardware, and you are done! You may also want a heat sink manufacturer (such as MyHeatSinks) to review it.