Sealing glass composition
AssigneeTechnology Glass Corporation
InventorsMaurice E. Dumesnil, Ulrich Schreier
Life of this patent
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Abstract
Lead borate and lead zinc borate glasses containing from 0.1 to 10% by weight cuprous oxide (Cu.sub.2 O) and fluoride, the molar ratio of cuprous oxide to fluoride being in the range 1:0.25 to 1:10, preferably in the range 1:1 to 1:5, and up to 5% by weight bismuth oxide. These glasses may be mixed with particulate refractory fillers in amounts up to about 56% by volume. The sealing glasses are useful for bonding ceramic, glass and metal parts together at low temperatures. They are especially useful as semiconductor package sealants.
Claims9
A sealing glass comprising a homogeneous mixture of lead oxide, zinc oxide, boron oxide, bismuth oxide, silicon dioxide, cuprous oxide and a minor proportion of at least one solid non-volatile metal fluoride, the proportions being lead oxide about 75 to 85 wt %, boron oxide about 8 to 15 wt %, zinc oxide up to 10 wt %, silicon dioxide 0.75 to 2.5 wt %, bismuth oxide to 5 wt %, cuprous oxide 0.5 to 5.5 wt % and non-volatile metal fluoride in amount such that the mol ratio of cuprous oxide to the fluoride content of the metal fluoride is in the range 1:0.25 to 1:10, said sealing glass being non-devitrifiable in that essentially no crystallization occurs when the glass is exposed to a temperature of 430.degree. C. for a period of 15 minutes.
Dependencies are inferred from the claim text.