Effect of Dispersion on Tape Casted Green Sheet Prepared from Bimodal-Type AlN Powders

Dispersion behavior of the slurries consisted of bimodal-type AlN powders was examined in non-aqueous solvent system.Azotropic solvent system and copolymer acidic dispersant were applied to the slurries.Measurements of the sedimentation height and the viscosity of the each slurry, and the test of particle size distribution of the each powder sample were conducted as examinations for the dispersion behavior at the various dispersant contents.The bimodal-type particle size distribution was continued after addition of the dispersant and small particle portions were increased as the dispersant content increases.The density of the green sheet was also increased as the dispersant content increases and a green density of 2.114 g/cm 3 was obtained at the sample prepared from 2.4 wt% dispersant content.The increase of large particle portions resulted in the surface defects of the green sheets.