Manganese in ruthenium dioxide-based thick film resistors.

The effects of Mn as additive on the microstructure, composition, and electrical properties of RuO2-based thick-film resistors were examined. Samples were prepared with pastes containing either MnO2 or Mn octoate in small amounts. Resistors were screen-printed and fired on 96% alumina and 99.5% beryllia. Dissolution of Mn in glass and phase transformation of oxides were studied, as well as the effect of Mn on interdiffusion phenomena in the resistors. The electrical properties of resistors with and without Mn were measured and compared. Mn is a very effective negative temperature coefficient of resistance driver; moreover, this additive brings a further beneficial effect on the performance properties of the resistors by preventing large inverse size effects in resistors with Ag-bearing terminations. It is shown that organometallic compounds are more suitable than oxides as a Mn source.