Electromigration failure in inkjet-printed Ag conductive lines

Abstract

Electromigration (EM) is crucial to the reliability of most conductive lines used in electronics. In the present study, the EM characteristics of inkjet-printed Ag conductive lines were analyzed under various EM acceleration conditions to comprehend the EM failure behaviors associated with inkjet-printed Ag lines with nanoparticle inks. The evolution of the porosity level in the microstructure of the inkjet-printed Ag lines during the EM test was investigated to locate the EM failure positions in the line and identify the main driving force for EM mass transport. Two theoretical models (resistometric and Black’s) were employed to analyze the activation energy and expected lifetime of inkjet-printed Ag lines. This study indicates that the EM of Ag cations is directed toward the cathode by the direct force resulting from the electric field–ion interaction, resulting in EM failure near the anode and hillock formation near the cathode of the inkjet-printed Ag lines. The activation energy computed from the theoretical models suggests that the surface diffusion of Ag through the inkjet-printed line plays an important part in the EM failure mechanism. This research was a pioneering attempt to experimentally investigate the EM performance of inkjet-printed Ag lines.