Influence of moisture contamination of lead-free transparent dielectric slurry for tape casting

During the process of milling glass powders of lead-free transparent dielectric materials, moisture contamination from the air affects the properties of the slurry of the green sheet and of the fired films. Several solvents used to gain suitable dispersion stability of the slurry and dispersants, such as ionic and polymeric agents, are studied for optimization of the slurry composition of the green sheet when the raw material is contaminated with moisture. Methyl alcohol as a solvent shows the best dispersion stability in all moistening conditions. Polyethylene glycol, a polymeric dispersant, produces excellent dispersion in all moistening conditions. Moisture in the starting materials does not greatly affect slurry stability, but it has a negative effect on the transparency of the fired dielectric thin films.