Change in Contact Resistance and Interfacial Microstructure at Press–Fit Connection Under Large Current Loading

Abstract

Press–fit connections are expected to replace soldering in the mounting of power modules. In the present study, the effect of contact resistance on temperature and microstructural development at the press–fit contact interface under high current loading were investigated. The larger the diameter of the through–hole into which the press–fit terminal is inserted, the lower the contact pressure and the higher the resistance of the press–fit connection. When a current of 100 A was applied, the temperature of the press–fit connection reached approximately 100°C, although it depended on the contact resistance. The intermetallic compounds were formed at the contact interface by loading high current, which decreased the contact resistance.