Whisker formation behavior on tin film plated in high magnetic field

High magnetic field was applied during Sn plating treatment for brass to change crystal orientation in the plating film. After prolonged heat treatment at 323 K, its effect on the formation of Sn whisker was investigated by scanning electron microscopic observations and X-ray diffraction (XRD). The XRD pattern of the film varied with the angle between the substrate and the direction of the magnetic field. When the specimen showed the XRD pattern similar to the film formed without the applied magnetic field, the whiskers were observed after the heat treatment. However, the generation of the whisker could not be confirmed in the case of the film with different XRD pattern. Therefore, it is expected that the plating treatment with the high magnetic field serves for inhibition of the whisker. The cases of Fe-42 mass% Ni alloy substrate were also discussed.