PCBs are sent to a modern soldering unit by ATF. Then, the tin-plating of printed circuit boards and soldering through-hole components (through-hole technology – THT) on the bottom of PCBs, is performed. This leads to lead-free soldering in a nitrogen atmosphere. The use of nitrogen reduces oxidation and improves the quality of soldering. 90% of the soldering process is performed automatically, the remaining 10% is additional manual soldering.