Lead free glasses for new generation of thick-film resistors: an explorative investigation

Pastes prepared with seven lead-free glass particles were screen-printed and fired on 96%-Al2O3 substrates. The fired films were studied in terms of sintering, devitrification, crack propagation and bleeding. The most promising glass compositions were selected for the preparation of RuO2-based tghick-film resistors (TFRs), on pre-fired PtAu - or PdAg based terminations; electrical properties of resistors (Rsvs:RuO2 volume fraction, temperature coefficient of resistanceand size effects) were investigated. The study eviced a myriad of complex phenomena occuring in the films, and emphasized the criticality in the choice of glass composition.