CONDUCTIVE POWDER PREPARATION AND ELECTRICAL-PROPERTIES OF RUO2 THICK-FILM RESISTORS

RuO2 powders were prepared under different conditions to vary their pr operties. A study was made of the powder properties and electrical cha racteristics of thick film resistors (TFRs) containing an RuO2 powder as a conducting component. Both crystalline size and specific surface area varied with calcination temperature but the change in the washing solution had different effects upon the two relationships. Variations in the total pore volume produce differences in the specific surface area at the same crystalline size. The resistivity of TFRs decreases a nd the temperature coefficient of resistance (TCR) becomes more positi ve with decreasing crystalline size. TFRs having conductive powder of higher specific surface area at the same crystalline size show lower r esistivity and higher TCR values.