Patent attributes
A first member has a plated layer. A second member is pressed against the plated layer and causes a tensile stress in the first member. A breakage probability is a probability of breakage of the plated layer caused by the tensile stress. A characteristic line represents a relationship between an elastic modulus of the plated layer and the breakage probability. A characteristic slope of the characteristic line is a ratio of an increase in the breakage probability to a decrease in the elastic modulus. A characteristic change point appears on the characteristic line at which the elastic slope increases to exceed a predetermined slope as the elastic modulus gradually decreases. A characteristic change elastic modulus is the elastic modulus at the characteristic change point. The plated layer contains at least a chromium component and has the elastic modulus larger than the characteristic change elastic modulus.
