| In recent years, with progress of study and application of the thick-film integrated circuit and correlation materials based on stainless steel, the thick-film elements base on stainless steel have been developed. The thick-film elements have a series of outstanding performance including high power density, small volume, cellular installation and aseismatic effect. Jn the paper, braking-resistance for numerical-control machine tool is made, a series of its service performance is studied including over loading, insulation and braking. This paper also make research on the influence of heat treatment technology on the resistance and TCR of different thick film elements including Ag-Pd, bismuth ruthenate and copper ruthenate, and influence of heat deposition technology on the consistency of resistance of the elements.The performance index of braking-resistance for numerical-control machine tool shows that over loading capability is five or seven times than rated power . The variation in the resistance( A R/R) is less than 1%. Insoluting resistance is larger than 1500 volt .The leaking current is less than 0.5 mA. Temperature coefficient of resistance (TCR) are always 1500 ppm/℃ and coefficient of voltage are -1300 ppm/V. The above performance could meet the requirement of braking.The result showed that heat treatment technology could preferably improve the electric characteristics of the thick-film elements. The best heat treatment technology of Ag-Pd resistance elements kept at 210℃for 130h, bismuth ruthenate resistance elements kept at 150℃ for 50h and copper ruthenate resistance elements kept at 180℃ for 50h.The result showed that the resistance value of resistance elements with low resistance value showed little variation by means of heat deposition, the variation in the resistance of elements decreased with increase of resistance value of elements. The variation in the resistance of elements deposited at 300℃ for 1000h was much than that of deposited at 70℃ for 1000h.
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