Sealing glass compositions

Abstract From the Canadian patent

Fluid, stable glasses useful for low-temperature sealing applications are made by adding jointly bismuth oxide zinc oxide, phosphorus pentoxide, titania and/or zirconium oxide to the lead oxide vanadium oxide binary. The phosphorus pentoxide may be replaced partially or entirely with niobium pentoxide and/or tantalum oxide. Sealing glass compositions comprising these low-melting lead-vanadia glasses in powder form and refractory fillers of lower thermal expansion for use in hermetically sealing semiconductor devices in ceramic packages are disclosed. Group V metal oxides particularly niobium-containing oxides are preferred fillers. Silver , metal is a preferred filler for making die-attach …