In thin film resistor chips and arrays, the main path for the heat, more than 90 %, is conduction through the body of the component, the solder pad, the PCB, and then convection to the ambient. The maximum junction temperature and internal thermal resistance of the surface-mount components are the only inputs from the component supplier in regards to thermal management. All other parameters are in the hands of the equipment designer: ambient temperature, cooling system, thermal behavior of the PCBs, maximum temperature of the solder joints, etc. In this technical note, we give designers some guidance on how to get the best from high-precision thin film chip resistors and arrays.