Environment-Friendly Fluxless Soldering Process for High Sealing Ability on Pressure Sensors

In a conventional soldering process, solvents, such as chlorofluorocarbons (CFCs), have been necessary to remove the flux-residue after soldering.

A new CFC-free fluxless soldering process has been developed to obtain high sealing ability even in a small soldering area. This new process utilizes a reducing atmosphere with an appropriate load and assembly orientation to solder the parts. Under this fluxless condition, it is found that appropriate loading and good solder-wettability of the upper part increase the wettability of the lower part.