Molecular Crystals and Liquid Crystals, Vol.551, 198-205, 2011
Influence of Oil Absorption on Lead-Free Transparent Dielectric Frit for Green Sheets
During the grinding of frit powder for the storage of raw materials, foreign substances such as oil can become attached to the surface of frit powder, adversely affecting the dispersion behavior and final properties of fired dielectric thin layers. This study reports the effect of the dispersion of artificially crushed frit powder containing oil. Green sheets of lead-free Bi2O3-ZnO-BaO-Al2O3 dielectric frit containing oil of 0 similar to 0.1 wt% were prepared by a tape casting method, which is an alternative to screen printing method. The frit powder was easily aggregated by contamination of oil, affecting its dispersion stability. However, the dispersion stability of the suspension liquid could be controlled by adjusting the amount of oil, and polymeric dispersant steric stabilization was effective to optimize the dispersion, resulting in enhanced physical properties. As the amount of oil contamination was increased, the number of pores and defects in the fired thin layer also increased. However, the optimized condition of the transparent dielectric thin layer at 500 degrees C at a low firing temperature was obtained through the use of polyethylene glycol (PEG).