For example B, the task is to find a space saving heat sink to keep a TO-220 device below the maximum 150°C junction temperature in forced convection at 400’/min. The device will be mounted with a labor saving clip. The information given is as follows: the power dissipated equals 12 W, the thermal resistance from the junction to the case of the semiconductor device is 2.5°C/W, maximum junction temperature is 140°C, and the maximum ambient air temperature is 50°C. In solving the equation to find RθSA, the end result is a thermal resistance of 5°C/W.