Integrated thick-film hybrid microelectronics applied on different material substrates
In this work, we have modified a low-temperature thick-film system previously developed for aluminium and aluminium alloy substrates in order to adapt it to ferritic and austenitic stainless steel, and glass substrates, which, unlike the common alumina substrate material, cannot usually be exposed to the standard high-temperature 850 °C thick-film firing cycle. Such substrate materials are useful for several important applications: high-response piezoresistive thick-film sensors (steel), displays (glass), high power electronics (aluminium-based materials) and heaters (steel and aluminium). We have developed several thick-film systems (dielectrics, resistors and conductors) chemically compatible and suitable for a wide range of thermal coefficient of expansion (TCE) values. This paper reports preliminary results on the electrical properties of these systems: sheet resistance and its thermal coefficient (TCR), compared with those of commercial thick-film materials.