Tin whisker-free tin or tin alloy plated article and coating technique thereof
AssigneeNippon Mining Co., Ltd.
InventorsHidenori Shimauchi, Keijiro Suzuki
Life of this patent
Estimating the term…
Abstract
A tin or tin alloy plated article, particularly a film carrier which is protected against the generation of tin whiskers characterized in having an indium plated layer on the substrate thereof and a tin or tin alloy plated layer on said indium plated layer. There are also disclosed a coating process therefor as well as a novel and unique electroless indium plating bath therefor, said indium plating bath is an acidic, electroless plating bath characterized by including an indium salt and thiourea or a derivative thereof.
Claims82
A tin or tin alloy plated article protected against the generation of tin whiskers characterized in having an indium plated layer on the substrate thereof and a tin or tin alloy plated layer on said indium plated layer.
A process for producing a tin or tin alloy plated article protected against the generation of tin whiskers characterized in that indium is plated on the substrate thereof by electroplating or electroless plating and then a tin or a tin alloy is plated on said indium plated layer by electroplating or electroless plating.
A process as in clam 37 wherein the thickness of said tin or tin alloy plated layer is in the range of 0.5 to 0.7 .mu.m.
A method for plating tin or a tin alloy on a substrate while protecting against the generation of tin whiskers characterized in that indium is plated as an undercoat on the substrate by electroplating or electroless plating before said tin or tin alloy plating.
A method as in claim 65 wherein said indium plating is conducted using an acidic, electroless plating bath including an indium salt and thiourea or a derivative thereof.
Dependencies are inferred from the claim text.