BGA cutter improvement utilizing nano-TiAlN coating layers synthesized by cathodic arc ion plating process

Ti/Al targets with various concentration ratios, Ti0.75Al0.25, Ti0.66Al0.33, Ti0.5Al0.5 and Ti0.33Al0.66 were used in a filtered cathodic arc ion plating system (FCAIP) to deposit the multilayer TiAlN films on Si wafer substrates and WC cermet ball grid array (BGA) cutters at various modulation wavelengths. Transmission electron microscopy (TEM), nanoindentation and BGA router were used to evaluate the characteristics of TiAlN layers and the performance of BGA cutters. TEM analysis revealed that the modulation wavelengths of deposited layers are less than 10 nm at various rotation speeds in FCAIP chamber and the crystal structure of TiAlN layer with the maximum hardness is NaCl-B1 structure using the Ti0.5Al0.5 target. The maximum hardness of multiple TiAlN layers measured by nanoindentation was 43 GPa, while the TiAlN monolayer exhibited the maximum hardness of 30 GPa in the same chamber. The TiAlN-coated BGA cutter deposited at the optimized condition exhibited a twice longer life and a higher machining speed in comparison with the conventional cutter.