Abstract: A reflow soldering system includes a reflow station with one or more soldering containers. Each container includes a base and a cover reciprocable to either open or close the container. When open, the container receives a printed circuit board/electrical circuit component assembly for reflow soldering, or permits the exit of such assembly after soldering. When closed, the container provides a fluid-tight seal between the chamber inside and the immediate outside environment. Container opening and closure are synchronized with an input conveyor providing assemblies to the container and an output conveyor removing the soldered assemblies, both of which are operated by a control system at a controlled rate of speed. When the container is closed, its internal environment is precisely controlled through heating elements in the container and several conduits for supplying air (heated if desired), for supplying an inert gas, and for drawing a vacuum.