For the first example, the goal is to find a space saving heat sink to keep a TO-220 device below the maximum 150°C junction temperature, in natural convection. The device will be screw mounted. The information given is as follows: the power dissipated equals 6 W, the thermal resistance from the junction to the case of the semiconductor device is 3°C/W, maximum junction temperature is 150°C, and the maximum ambient air temperature is 65°C. In solving the equation to find RθSA, the end result is a thermal resistance of 11.2°C/W.