PCF Thin Film Resistors Welwyn / TT Electronics PCF Thin Film SMT Resistors are constructed from a thin-film material selectively deposited on a 96% alumina substrate with metallic contacts at each end and supplied with 100% Sn matte plated wrap-around terminations suitable for soldering. The wrap-around terminations supplied to the PCF Series Thin Film Resistor chips from Welwyn / TT Electronics have an electroplated nickel barrier and tin coating that ensures excellent 'leach' resistance properties and reliable contact to the PCB. These robust resistors can operate at a maximum temperature of 125ºC, and up to 155ºC for higher power grades. PCF Series Thin Film Resistors offer an extended ohmic range from 1R-3M and superior humidity performance at a passivated range.