Glasgemenge,insbesondere als Material fuer Passivierungs- und Schutzschichten fuer Festkoerperbauelemente

A glass consists essentially, in moles per cent of: PbO, 23-50; Al2O3, 0-19; B2O3, 6-18 SiO2, 33-65; 0.1-1.0 mole per cent of one of Nb2O5, ZrO2, TiO2 and Ta2O5. The glass may have coefficient of linear expansion of (50-70) x 10-7/ DEG C. The glass may be applied to a semi-conductor device 10 comprising Si wafer with PN junctions 14 and 15, to the surface of which is applied an optional continuous oxide layer 16, e.g. of silicon oxide and a layer of the glass 17 chemically bonded to layer 16. Layer 16 may be formed: by heating the body to 900-1400 DEG C. in an atmosphere of air saturated with water vapour or in an atmosphere of steam; by electrochemical treatment; or by thermal decomposition of a siloxane compound. Glass layer 17 may be applied by spraying, settling on silk-screening finely divided glass particles, followed by firing. One method of application of the glass particles comprises centrifuging the body in a colloidal suspension of glass particles of mean size, e.g. 0.1-0.7 m in an organic fluid of dielectric constant 3.4-20.7. The glass may be fused at 500-950 DEG C. Holes may subsequently be etched, e.g. by HF, through layers 17 and 16 to expose portions of the semi-conductor regions 11, 12 and 13, to which ohmic contacts 18, 19 and 20 may be applied by evaporation of a metal. Specifications 992,044 and 994,814 are referred to.