Glass Composition for the Thick-film Resistors

摘要

The considerable part of thick-film inks (TFI) for the production of hybrid circuits using screen-printing technology is glass. Phosphate glasses for production of thick-film resistors (TFR), which can substitute now currently used lead borosilicate glasses, have been investigated. The TFI were produced from glass and RuO_2 by the addition of the screening agent and vehicle and deposited on an alumina substrate Rubalit®708. Phosphate glasses have suitable thermal and chemical properties for the formation of high-quality coating on alumina with a high electrical resistivity, sufficient chemical durability and viscosity-temperature relationship suitable for TFI. A complete saturation of RuO_2-film with the glass phase without chemical interaction between glass-RuO_2 and glass-alumina substrate was found at sintering temperature 850°C. The film near the substrate has a low content of Ru and a high content of Al owing to diffusion of Al from the substrate. Owing to suitable properties the investigated phosphate glasses are convenient to be applied in the production of RuO_2 based TFR by printing on alumina.