Abstract: A thermal processing chamber configured to enclose and heat treat a single electronic substrate at an exposed surface, such as a wafer or electronic circuit board being re-melted, includes an enclosed gas tight and particle free heat insulated chamber. An electronic substrate support is placed within the enclosed gas tight and particle free heat insulated chamber. A convection gas inlet distribution manifold adjustable in spatial relation towards and away from the surface to be treated provides a flow of heated gas over and onto the exposed surface of the electronic substrate to be treated. A heated convection gas outlet is placed below the electronic substrate for the collection of heated gas after flowing over, around and below the exposed surface of the electronic substrate to be treated. A door is movable between and open and closed position. The door opens a path to move the electronic substrate into and out of the chamber to and from the electronic substrate support in an open position.