JPS5645055A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a stable semiconductor device having high dielectric strength and high reliability by including SiO2, B2O3, ZnO, Al2O3, Sb2O3, As2O3, PbO to compose a glass layer for protection. (However, the oxides of a transition element and a rare earth element having two kinds or more of valence should be 0.03% or less). CONSTITUTION:The following are each composition of glass shown in percent indication by weight: 1; SiO2 of 8% or less - easy to be exfoliated and has inferior chemical durability. 2; SiO2 of 20% or more - hard to be glazed. 3; B2O3 of 17% or less - transparency will be lost. 4; B2O3 of 30% or more - will not equally be glazed. 5; ZnO of 53% or less - transparency will lost. 6; ZnO of 63% or more - crystals will be separated in the glass. 7; Sb2O3, As2O3 of 1% or more as a deforming agent - will induce a deterioration in resisting pressure. 8; PbO of 3% or more - will induce a decrease in resisting pressure. 9; Al2O3 should be 3-10% to give stability and dielectric strength will be equalized and variations in dielectric strength will be prevented by fixing the content of the oxides of a transition element or a rare earth element to a predetermined amount. With a semiconductor protected by a glass film composing of the above composition, a high reliability semiconductor will be obtained.