Submicron Cu@glass core-shell powders for the preparation of conductive thick films on ceramic substrates

Abstract

Coating Cu powders with glasses to form a core-shell structure provides an important route to achieve uniform distribution of glass components in Cu pastes for the fabrication of various electronic devices. In this study, submicron Cu powders are synthesized via a chemical solution method at first, and then coated with Bi-Si-B-Zn-Al glass by a sol-gel method to form submicron Cu@glass core-shell powders which are then prepared into Cu pastes with different glass contents. The Cu@glass pastes are printed on alumina ceramic substrates and sintered at temperatures ranging from 600 to 800 °C to form conductive thick films. Enhanced anti-oxidation properties are observed for the Cu@glass core-shell powders. The Cu pastes can be sintered into conductive films with a good electric conductivity and adhesion strength on alumina substrate at a relatively low temperature of 600 °C. A low resistivity of 3.0 µΩ cm is achieved for the sintered Cu film with a glass content of 6 wt%. The glass shells are observed to transform into uniformly distributed glass phases which provide advantages for the formation of Cu-grain conductive pathway at a low sintering temperature.