NICKEL-TUNGSTEN ALLOY PLATING SOLUTION AND PLATING METHOD

摘要

PURPOSE: To prepare a nickel-tungsten alloy plated film small in plating stress and free from the generation of crack not only at the time of plating film forming but due to heat cycle. ;CONSTITUTION: A plating solution containing nickel sulfamate, a tungsten compound and citric acid, with a total concentration of nickel molar concentration (Ni) and tungsten molar concentration (W) of 0.1-0.4mol/l (not including 0.4mol/l), a tungsten mol ratio (W/(W+Ni)) of 0.35-0.8 and having citric acid molar concentration higher than the total molar concentration of nickel and tungsten and adjusted to pH 6-7 is used. A material to be plated is plated with the plating solution heated to 60-80°C at 3-30A/dm² current density.;COPYRIGHT: (C)1995,JPO