In CFX the interface model that handles contact resistance and thin material heat conduction only calculates conduction heat transfer in the direction normal to the interface. Because of the inability of heat to spread laterally, the calculation at corners will be wrong. The solution is to use a shell conduction model at the thin interface, so that heat can spread parallel as well as perpendicular to the thin material. The shell conduction model is offered only in Fluent, so CFX users will have to mesh the interior of the thin object, of move the analysis to Fluent.