Inert atmospheres reflow soldering

The physical plant costs are generally similar for both a Pb-free assembly process and a Sn-Pb line. The two possible differences would be electricity usage, which may be greater with the Pb-free line due to the higher soldering temperatures, particularly with respect to a reflow process, and the need for an inert atmosphere capability for the soldering machine. 

When electronic products are constructed, individual components such as chips, condensers, or conductor boards must be connected to fully functional electronic devices. This crucial step is usually performed using reflow or wave soldering processes. Both processes can be performed either in air or in controlled and inert atmospheres (see Fig. 2.24). Using a controlled atmosphere, however, provides the following substantial benefits ... 

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