Abstract
Improving the electrical conductivity and reliability is a critical issue for developing copper-filled electrically conductive pastes
that are expected to alternate the conventional silver-filled pastes in the electronics packaging field. This work investigated the effect
of surface treatment through amino ethanol and its derivatives on copper fillers to improve the electrical conductivity and reliability
of copper-filled electrically conductive pastes composed of a resol-phenolic resin binder. The amino ethanol surfactants effectively
accelerated the electrical conductivity development in the pastes during curing, increasing the magnitude of the acceleration effect
with the number of terminal hydroxyl groups. Although using amino ethanol surfactant alone could not improve the electrical
reliability during exposure to a humid environment, co-treatment with oleic acid enhanced the reliability. By contrast, introducing a
terminal amino group to the surfactant improved electrical conductivity and reliability. The chemical behavior of copper complexes
formed by the interfacial reaction during the surface treatment is needed to clarify the mechanisms of enhancing electrical
conductivity and reliability. This means control of the interfacial chemistry will be essential for developing advanced copper-filled
conductive pastes.
