1994 年 45 巻 7 号 p. 691-694
To prevent the corrosion of palladium-plated ferro-alloy bases for lead frams, the effect of pulse plating on nickel deposits used as the underlayer for palladium-plated layers was investigated.
The following results were obtained.
(1) For nickel deposition at a current density of 4A/dm2 and a pulse cycle time of 10ms, fine crystal grains and a smooth surface were obtained at a duty cycle of 9%.
(2) The nickel underlayers deposited using pulse current at a duty cycle of 9% improved the corrosion resistance of the palladium-plated ferro-alloy bases more than those deposited using smooth DC. These results suggest the feasibility of applying palladium plating to ferro-alloy lead frames.