FIW is an alternative wire to build switching transformers typically using TIW (Triple Insulated Wires). Due to the big choice of overall diameters it allows to produce smaller transformers at lower costs. At the same time FIW has better windability and solderability compared to TIW.
FIW is produced in a multiple coating process, which guarantees insulation without any defects.
It has been sold successfully for several years for the automotive industry and for applications which do not require UL-Approval acc. to UL 60950.