Reflow soldering with long industrial convection ovens is the preferred method of soldering surface mount technology components or SMT to a printed circuit board or PCB. Each segment of the oven has a regulated temperature, according to the specific thermal requirements of each assembly. Reflow ovens meant specifically for the soldering of surface mount components may also be used for through-hole components by filling the holes with solder paste and inserting the component leads through the paste. Wave soldering however, has been the common method of soldering multi-leaded through-hole components onto a circuit board designed for surface-mount components.