Infiltration is a process in which the pores inside a sintered contact are filled with either molten silver or copper, often referred to as the infiltrant. Infiltrating is performed through high temperature heating of the sintered contact and the infiltrant in furnaces which have a reducing atmosphere. Aside from the furnace atmosphere, temperature and process times are critical elements of the infiltration process. As such, these parameters are closely monitored throughout the infiltration process. Depending on the final application, infiltrated contacts are supplied with or without serrated backs. The serrations provide a surface that captures the excess infiltrant and is also well suited to the resistance brazing process. Where high currents are involved, the surfaces to be brazed are typically machined flat prior to solder flushing.