The characterisation of lead-free thick-film resistors on different low temperature Co-fired ceramics substrates

[Display omitted] ► Lead free thick film resistors based on ruthenium oxide were developed. ► The compatibility of resistors with different LTCC substrates was evaluated. ► The interactions between resistors and glassy LTCC substrates were not detected. ► Electrical characteristics were comparable with commercial thick film resistors. Lead-free thick-film resistors were synthesised and investigated. The thick-film resistor materials with nominal sheet resistivities from 50ohm/sq. to 50kohm/sq. were prepared using combinations of two lead-free glasses with reflow temperatures at 940°C and 1240°C, respectively, and two RuO2 powders (fine-grained and coarse-grained RuO2). The thick-film resistors were printed and fired on alumina and on low temperature co-fired ceramics substrates and fired at 850°C and 950°C. The fired resistors were investigated by X-ray powder diffraction, by scanning electron microscopy and by energy dispersive X-ray analysis. The sheet resistivities, temperature coefficients of resistivity, gauge factors and noise indices were measured.