Soldering without using liquid fluxes is common for the assembly of electronic, optical and mechanical components. After all, these chemicals and their residues can adversely affect the performance. Chemical fluxing includes removing oxide films from metal surfaces, which otherwise impede spreading and humidification. This is essential for successful soldering and joint formation. Fluxless soldering processes use alternative strategies to achieve the same goal. In fluxless soldering oxide films are removed by a reduction, displacement or dissolution.