Sealing glass compositions

Abstract

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 compositions.

Dependencies are inferred from the claim text.