LOW MELTING PHOSPHATE GLASSES TO TRICK-FILM RESISTORS

抄録

Low melting zinc metaphosphate glasses (ZnO:P₂O₅=1:1, SiO₂ 8-12, Al₂O₃ 2-8 mol.%) for thick-film resistors (TFR) have been investigated.
A polymeric chain of investigated glasses is made up of PO₄ adjacent tetrahedra connected at two corners upon bridging oxygens, so that there are two non-bridging oxygen atoms on each tetrahedron. With modifier ion Zn silica-like network is realised.
Following properties of glasses were studied: thermal expansion coefficient, transformation and softening temperatures, chemical durability, density, electrical resistivity depending on temperature and presence of crystalline phases. Viscosity as a function of the temperature (740÷1120°C) of the glass melts depends on the content of Al₂O₃.
Values of viscosity of glasses containing Al₂O₃ 5≤6mol.%, at the firing temperature (about 850°C) for TFR on alumina substrate (96% Al₂O₃) are 10 ^2,1÷10 ^2,6 Pa. s; Eη-152÷163 kJ/mol.
Owing to the suitable thermal, electrical properties and viscosity, the zinc metaphosphate glasses could be applied in production of TFR on RuO₂ basis.