Micro motion at the failed contact interfaces

On inspection of failed connector's contacts, various wear tracks of micro motion are found. The tracks appear as straight line, curve and twisting. The effect of micro motion not only produces wear debris of contact metals and their oxidation products, but also grabbles and accumulates contaminants which cause high and fluctuated contact resistance. Analysis on the cause of micro motion that related to external vibration and shocks are carried out. Supporting experimental results are also discussed.