MANUFACTURING METHOD OF BARIUM TYPE CONDUCTING POWDER FOR PB FREE THIN FILM RESISTANCE PASTE

摘要

A manufacturing method of barium-based conducting powder for Pb free thin film resistance paste is provided to perform mass production and use inexpensive raw materials, compared with the existing dry process using a ruthenium compound and barium compound, and to ensure excellent the rheological property of a paste and excellent electrical characteristic including a resistance temperature coefficient of a resistor, pressure- resistance characteristic and noise by obtaining barium ruthenate having minute particle size and uniform particle size. A manufacturing method of the barium system conductive powder for the free lead thick film resistance paste comprises (A) a step for dissolving a ruthenium metal powder in a strong acid or strong base or alkali- fusing; (B) a step for mixing a barium compound aqueous solution containing a dispersant capable of controlling particles in a ruthenium salt aqueous solution manufactured in the (A) step to obtain hydrate barium ruthenate; (c) carrying out heat-treatment of the hydrate barium ruthenate manufactured in the (B) step at 320deg.C or 1000deg.C to obtain the barium ruthenate (BaRuO3) powder; and (D) a step for using an inorganic acid to remove the impurity of the barium ruthenate powder manufactured in the (C) step.