Low temperature sealing glasses

摘要

Lead borate and lead zinc borate glasses containing from 0.1 to 10% by weight cuprous oxide (Cu2O) 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, up to 5% by weight bismuth oxide and from 0.1 to 5.0% alumina are disclosed. These glasses are mixed with particulate lead titanate in amounts up to about 56% by volume. These mixtures have very low coefficients of thermal expansion and are useful for bonding ceramic, glass and metal parts together at low temperatures. They are especially useful as semiconductor package sealants.