Analytical Quantification and Effect of Microstructure Development in Thick Film Resistor Processing

Microstructure developments of RuO₂ based thick film resistors during firing as a function of glass viscosity were analytically quantified and its effect on the electrical property was investigated. The microstructure development was retarded as the viscosity of glass was increased. It was found that the viscosity range for each stage of microstructure development are as follows ; 7500-10⁵ Pa·s for the glass sintering, 2000-7500 Pa·s for the glass island formation, 700-2000 Pa·s for the glass spreading, and 50-700 Pa·s for the infiltration. The sheet resistivity decreased as the viscosity of glass in the resistor film increased due to the higher chance of sintering for the conductive particles with the higher viscosity of the glass.