Richard Robert Tetschlag

US Patent:

50133608, May 7, 1991

Filed:

Sep 15, 1989

Appl. No.:

7/407470

Inventors:

Leo Finkelstein - San Francisco CA
Maurice E. Dumesnil - Los Altos Hills CA
Richard R. Tetschlag - San Jose CA

Assignee:

VLSI Packaging Materials, Inc. - Sunnyvale CA

International Classification:

C03C 312
C03C 321
C03C 824
C03C 1400

US Classification:

106 123

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.