Acoustic emission testing of electrical stressed copper trace

Copper becomes more and more important in the electronic industry. This metal is more resilient than conventional materials (like aluminium) due to the higher electrical and thermal conductivity. During several electrical stress pulses the copper changes. The surface can melt up and cracks and voids can develop inside the copper specimen.

In this paper we use acoustic emission testing to analyse copper degradation especially of copper and copper traces. It is evaluated if an acoustic wave excited by a thermo-electrical stress pulse can be detected by a simple measurement setup and if a correlation between the acoustic signal and the degradation exists. The idea is that during the degradation, the behaviour of the material changes which in turn influences the emitted acoustic signal.