Microscopic Observations of the Fatigue Crack Initiation Behavior in Film Material

Abstract

In recent years, films have been widely used as small-sized and light-weight materials for electronic parts. For reliability of these parts, it is important to know fatigue properties of the film. In this study, the crack initiation behavior from the notch in cold rolled copper films was observed by scanning electron microscope in relation to the crack propagation behavior to the film thickness direction. And an effect of rolling direction on the crack initiation behavior was studied using two types of specimen that rolling direction was parallel and perpendicular to the loading direction.