Preparation And Study Of Fe₃Si-based Thick Film Resistance Paste

According to the development direction of thick film resistive paste,Fe3 Si is used as the conductive phase with the advantages of low cost,high temperature resistance,corrosion resistance and low conductivity,Fe₃Si-based thick film resistive paste was prepared by orthogonal test method,Fe₃Si-based thick film resistors were prepared by screen printing in this paper.The effects of the solid content of the paste,the content of the glass powder,the sintering temperature and the particle size of the conductive phase on the resistivity of the thick film were investigated by XRD and SEM.The effect of solid content on the resistivity of Fe₃Si-based thick film resistive paste was studied.The result shows that the square resistance of the thick film resistive sample decreases as the solid content in the Fe₃Si-based thick film resistive paste increase.The resistance value is the smallest,and the resistance temperature coefficient is negative maximum when the solid content of the Fe₃Si-based thick film resistive paste reaches 75 wt.%.The electrical properties of the thick film resistors under different glass powder contents were analyzed.The research indicates that with the increase of the content of glass powder,the resistance value of the thick film resistive increases at first,then decreases,and increases finally,the temperature coefficient decreases firstly in the forward direction,increases in the negative direction,and then reduce the positive.The resistance of the thick film resistor is the smallest and the temperature coefficient is negative maximum when the glass powder content reaches 45%.The electrical properties of the thick film were analyzed at different peak sintering temperatures.The results show that the square resistance of the sample increases and the resistance temperature coefficient decreases with the increase of the peak sintering temperature,may be due to the rate of breakage of the conductive strand is greater than its connection.The square resistance of the sample decreases,and the resistance temperature coefficient is negative maximum when the peak sintering temperature reaches 740 ?.The electrical properties of the conductive phase size in the Fe₃Si-based thick film resistors were studied.It is concluded that the Fe3 Si alloy is oxidized to produce Fe2O3 as the average particle size of the conductive phase decreases,the resistivity of Fe2O3 is smaller than Fe3 Si,the temperature coefficient of Fe2O3 is positive,Therefore,while the sample side resistance decreases and its temperature coefficient decreases positively.The uniformity of the conductive phase particles is reduced when its average particle size decreases,the temperature coefficient of the thick film resistive sample exhibits a negative increase owing to the effect of the increase of the barrier resistance on the temperature coefficient is greater than that of Fe2O3.