Hot gas soldering is a process that is commonly used in applications where the workpiece thermal mass is small and the melting temperature of the solder is relatively low. This article describes the characteristics of hot gas heating that are critical to its effectiveness in soldering. These characteristics include the focus of gas flow, gas flow rates (velocity and volume), gas temperature, and typical gas media. The article explains the thermal profile of a component being soldered and the temperature across adjacent components, which helps to understand time-temperature relationship. It concludes with a discussion on reliability concerns and processing concerns when using hot gas soldering in electronics assembly.