Processing of barium titanate tapes with different binders for MLCC applications - Part I: Optimization using design of experiments

Twenty-four kinds of BaTiO3 slips for MLCC application were investigated using three different binder systems: one solvent-based, and two water-based with water-soluble acrylic binder and aqueous emulsion binder systems. The half-fractional factorial design method was used for each system with four input factors with two levels for each factor. Tape casting, K-square preparation, sintering and characterization were conducted. Slip viscosity, mechanical properties of the green tapes, green and sintered density of K-squares, and dielectric permittivity were analyzed as output responses using statistical analysis methods. Most of the green body properties from solvent-based system such as tensile strength, tape morphology and bulk density depended on the ceramic powder. While, dispersant was the most significant factor for the two water-based systems. The sintered properties such as microstructure and dielectric permittivity for the three systems depended significantly on the type of ceramic powder. Finally, an optimization was performed for each system by means of a scorecard which was used to prioritize all samples to important output responses through the numerical ranking method. (C) 2003 Elsevier Ltd. All rights reserved.