Modern HFE co-solvent cleaning processes are available options if a short process, drying time and/or water-free cleaning is required. This is often utilized in the military and aerospace industries. HFEs (hydrofluoroethers) were developed as a replacement for CFCs or similar solvents exhibiting the following properties: nonflammable, non-conductive, dries quickly and residue-free.
With a co-solvent, HFE is used in a cleaning bath with spray-under-immersion or ultrasonic agitation in order to dissolve persistent residues. The rinsing step takes place in a bath with HFE only and subsequently with steam rinsing. The substrates are then dried by intensive cooling. This process must be carried out in a cleaning machine with efficient cooling technology, preventing the evaporation of HFE.