A study on the conductive behavior of copper filled pastes for microelectronic packaging substrates

The objective of this study is to investigate the conductive behavior of copper conductive pastes and compressed Cu powders and the dependence on powder shape and oxidization of Cu powders at various temperatures. The applied compression pressures and the contact areas between Cu powders are also investigated with respect to how this affects their conductive behavior. The conductive behavior of conductive paste and compressed Cu powders were monitored by the measurement of the resistance of cured conductive paste via a four-points probe and the resistivity of samples was calculated for comparison. The results of this study indicate the conductive behavior of cured conductive pastes and compressed Cu powders are strongly dependent on the oxidation of Cu powders and slightly dependent on the powder shape. The conductive behavior of compressed Cu powders is strongly dependent on the compressed pressures and slightly dependent on the contact areas between Cu powders. The uncoated-Cu powders are easily oxidized and a Ag coating can improve the oxidation-resistance for Cu powders.