Conductive glass sealants with Ag nanoparticles prepared by a heat reduction process

• Conductive Ag-precipitated glass powder was prepared by a heat reduction process.
• Microstructures and electrical properties were investigated.
• Ag-precipitated glass powder showed a uniform dispersion of Ag nanoparticles.
• Electrical conduction was due to a tunneling effect between Ag nanoparticles.

Conductive Ag-precipitated glass powder was prepared by a heat reduction process of the glass/AgCl composite powder and its electrical conductivity was compared to conventional Ag-particle mixed glass powder. The Ag-precipitated glass powder with 30 wt.% dispersed Ag particles of diameter of 20 to 300 nm and the baked film made of the powder showed a good electrical conduction from 400 °C to 700 °C. On the other hand, the baked films made of the Ag-particle mixed glass powders of Ag particle size of 300 nm with 35 wt.% Ag content and that of size of 20 nm with 30 wt.% Ag content showed a poor electrical conduction. The electrical conduction of the film of Ag-precipitated glass powder resulted from a uniform dispersion of Ag particles. Since no continuous network of Ag particles was found in the microstructure observation of the glass powders, or films, the origin of the electrical conduction was considered to be due to a tunneling effect between the well-dispersed Ag particles.