Detailed analysis of contact resistance of fretting corrosion track for the tin plated contacts

Tin plated terminals are widely used for automotive connectors due to low cost and higher reliability. But it is observed that contact resistance of tin plated terminal increased due to fretting corrosion, which is originated from heat cycle or vibration. In order to clarify the degradation of terminal, it is necessary to obtain the contact resistance distribution on fretting corrosion wear of tin plated contact in detail, because the terminal has more than two point of conduction point at least. Thus, the detail measurement of resistance distribution in fretting corrosion wear is performed to estimate contact resistance at mating terminal. As the result, in the region of higher concentration of oxygen measured by EDX analysis, the resistance is tended to be measured higher. And the contact resistance of whole contact wear is estimated by static electric field analysis based on film resistance distribution at contact wear. These analysis results are approximately agreement with the contact resistance on fretting corrosion experimentally. That means the degraded resistance of terminal mating would be estimated using by this technique.