Abstract: A layer of aluminum is formed on a surface of a thermal expansion buffer which is used in a semiconductor package. A semiconductor die is attached to the aluminum using a die attach material. An electrical connection for the die is created by attaching a wire from the semiconductor die to the aluminum surface of the buffer. This provides a reliable semiconductor package useful in a high temperature environment.

Abstract: An insulating or passivation glass consisting of 36 to 40 volume percent zircon and the balance is a base glass consisting essentially of 2 to 6 percent-SiO.sub.2, 70 to 75 percent-PbO 5 to 9 percent-ZnO, 0 to 4 percent-BaO, 2 to 5 percent-CdO, 0 to 2 percent-TiO.sub.2 and 10 to 14 percent-B.sub.2 O.sub.3, all of said percentages being weight percent.

Abstract: A method for sealing two ceramic pieces, a lead frame and a semiconductor chip together involving the application of pressure to a layer of sealing glass composition which remains vitreous throughout the sealing process is disclosed. The sealing glass composition comprises a mixture of sealing glass and zirconium silicate in the volume percentage amounts of 50-62 percent of glass and 50-38 percent of zirconium silicate. The glass components comprise, as a percentage weight of the glass alone, SiO.sub.2 about 0-2 percent, PbO about 65-72 percent, ZnO about 5-10 percent, PbF.sub.2 about 2-10 percent, CdO about 1-5 percent, TiO.sub.2 about 0.5-3 percent and B.sub.2 O.sub.3 about 10-14 percent.