A deformation and a breakdown after buckling of metal films plated on silicon whisker were studied. The tensile stress of deformed column with one end fixed and the other pinned at maximum curvature, F(α)max, was derived, and each F(α)max of silicon whisker and plated metal films was calculated. When F(α)max exceeds tensile strength of constituent metal film, a breakdown is occurred. Critical load for buckling and overdrive at breakdown can be estimated with elastic constant, distance from neutral plane, and thickness of metal film, and length of silicon whisker.
The polarization resistance of nickel subjected to NaCl solution during wet/dry cycling conditions was monitored using an EIS impedance technique. The influence of relative humidity (RH), temperature, surface orientation and length of wetting period on the corrosion process of nickel is described. The average mass loss per wet-dry cycle (AML) was calculated during the exposure. The nickel plates corroded more substantially on the upward direction than those on the downward direction. The corrosion mass loss of nickel increases with increasing RH, temperature and length of wetting period. The corrosion process of nickel is anodically controlled by nickel dissolution during a full immersion in NaCl solution and cathodically controlled by a reduction of oxygen under thin electrolyte layers during the drying period. The corrosion rate of nickel decreases rapidly during the initial stages of exposure. It then decreases slowly and eventually attains the steady state during the last stages of exposure.