Mixed-metal system conductors for LTCC (low-temperature co-fired ceramic)

A composition for forming transition vias and transition line conductors is disclosed for minimizing interface effects at electrical connections between dissimilar metal compositions. The composition has (a) inorganic components selected from the group consisting of (i) 20-45 wt % gold and 80-55 wt % silver and (ii) 100 wt % silver-gold solid solution alloys, and (b) an organic medium. The composition may also contain (c) 1-5 wt %, based upon the weight of the composition, of oxides or mixed oxides of metals selected from the group consisting of Cu, Co, Mg and Al and/or high viscosity glasses mainly containing refractory oxides. The composition may be used as a multi-layer composition in a via fill. Multi-layer circuits such as LTCC circuits and devices may also be formed using the composition for forming transition vias and transition line conductors.