Abstract: A sealing glass composition containing refractory filler of lower coefficient of thermal expansion for use in sealing alumina package for electronic components is disclosed. The composition consists essentially of low melting glass powder and cordierite powder in proportion of 2-30% by weight of the total composition, and optionally, .beta.-eucryptite, .beta.-spodumen, lead titanate or zircon in a proportion, respectively, not exceeding 15% by weight of the total composition. The low melting glass has a composition of 77.0-86.0 wt. % of PbO, 6.0-15.0 wt. % of B.sub.2 O.sub.3, 0.5-6.9 wt. % of ZnO, 0.1-3.0 wt. % of SiO.sub.2, 0-3.0% of Al.sub.2 O.sub.3 0-2.0% of alkali earth metal oxide, 0-1.5% of SnO.sub.2 and 0-1.0% of alkali metal oxide.

Abstract: A silver metallizing paste for attachment of silicon semi-conductive devices in lead-frame packages, specifically ceramic packages, which is less expensive than a gold preform but useable in hermetic packages, and provides better electrical and thermal conductivity, and higher bond strength, than silver polyimides. From 25 to 95% of silver is blended with a low-melting glass, preferably one having 95-96% PbO, and a paste or ink is formed with a suitable vehicle at 75-85% solids. Use of the paste follows conventional practice. Selection of Ag:glass ratio depends on the type of die bonding to be used. The paste is particularly useful in MOS technology, where low contact resistance is required, and also finds applications as a solder substitute and bonding chip capacitors. It is most advantageous in attachment of larger-area integrated circuits in that stress cracking associated with the gold-silicon eutectic is avoided.

Abstract: Acid and alkali oxides are smelted for an extended period of time at a first elevated temperature above their melting temperatures. The smelted mixture is then quenched in water and fritted. The fritted mixture is then disposed between a pair of members which are to be hermetically sealed relative to each other. The fritted mixture is then at least partially fused in an oxygen atmosphere at a second temperature below the first temperature for a relatively short period of time. The at least partially fused mixture is then rapidly cooled in air. In this way, the mixture is provided with a partially amorphous state and a partially crystalline state. The crystals in the mixture are disposed primarily at the borders of at least a particular one of the members to be sealed.The mixture hermetically seals the two members, is resistant to acids and alkalis and inhibits the propagation of cracks.

Abstract: An improved optical glass having an index of refraction of .gtoreq.1.69, an Abbe number of .gtoreq.38, and a density of .ltoreq.3.25 g/cm.sup.3, represents a further development of another optical glass recently provided by the same inventors. The new glass has improved suitability for continuous-tank manufacture and increased acidproofness and differs from the other glass in its content of 0.5-4.0% by weight of P.sub.2 O.sub.5 ; its sum total of SiO.sub.2 +B.sub.2 O.sub.3 +Al.sub.2 O.sub.3 +P.sub.2 O.sub.5 being 38.5-41.5% by weight; and its sum total of MgO+CaO being 13-17.5% by weight. The full glass composition, e.g. is in % by weight:______________________________________ SiO.sub.2 26.0-32.5 B.sub.2 O.sub.3 6.0-12.0 Al.sub.2 O.sub.3 0-3.0 P.sub.2 O.sub.5 0.5-4.0 SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 + P.sub.2 O.sub.5 = 38.5-41.5 Li.sub.2 O 0-5 Na.sub.2 O 0-6 K.sub.2 O 0-8 Li.sub.2 O + Na.sub.2 O + K.sub.2 O = 4.5-12.0 MgO 0-8 CaO 9-16 MgO + CaO = 13-17.

Abstract: Optical components can be pressed with such a precision that grinding and polishing of the formed components is not necessary, from glasses containing 45-55 wt. % P.sub.2 O.sub.5, 3.5-9 wt. % Al.sub.2 O.sub.3, 5-20 wt. % K.sub.2 O, 0-3 wt. % Li.sub.2 O, 8-15% BaO, 4.5-9 wt. % ZnO, 0-6 wt. % MgO, 0-18 wt. % PbO, 0-1 wt. % SiO.sub.2, 0-3 wt. % B.sub.2 O.sub.3, 0-2 wt. % TiO.sub.2.

Abstract: An optical and ophthalmic glass having an index of refraction of .gtoreq.1.69, an Abbe number of .gtoreq.37, and a density of .ltoreq.3.30 g/cm.sup.3, consists essentially of (in % by weight):______________________________________ SiO.sub.2 18-36 B.sub.2 O.sub.3 3-18 GeO.sub.2 0-8 Al.sub.2 O.sub.3 0-6, wherein SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 + GeO.sub.2 25-39 P.sub.2 O.sub.5 0-14, wherein SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 + GeO.sub.2 + P.sub.2 O.sub.5 = 30-44 Li.sub.2 O 0-12 Na.sub.2 O 0-14 K.sub.2 O 0-18 Li.sub.2 O + Na.sub.2 O + K.sub.2 O = 2-18 MgO 0-15 CaO 7-25 MgO + CaO 15-32 SrO 0-13 BaO 0-17 ZnO 0-15 PbO 0-10 SrO + BaO + ZnO + PbO 0-20 TiO.sub.2 3-14 Nb.sub.2 O.sub.5 0-13 WO.sub.3 0-10 TiO.sub.2 + Nb.sub.2 O.sub.5 + WO.sub.3 = 10-21 ZrO.sub.2 0-15, La.sub.2 O.sub.3 0-20 Y.sub.2 O.sub.3 0-16 Gd.sub.2 O.sub.3 0-16 Yb.sub.2 O.sub.3 0-10 La.sub.2 O.sub.3 + Y.sub.2 O.sub.3 + Gd.sub.2 O.sub.3 + Yb.sub.2 O.sub.3 = 0-20 Ta.sub.2 O.sub.5 0-13 HfO.sub.2 0-5 SnO.sub.2 0-6.

Abstract: A powder having a negative coefficient of linear thermal expansion and sealing compositions containing the same are disclosed wherein the powder is a .beta.-eucryptite particle having on the surface thereof a layer of tin oxide, titanium oxide, and/or zirconium oxide.

Abstract: A low temperature sealing glass composition consisting of 60-80% by weight of vitreous solder glass of PbO-B.sub.2 O.sub.3 system having a deformation point of 350.degree. C. or less, and 20-40% by weight of willemite. The vitreous PbO-B.sub.2 O.sub.3 system glass comprises 70-90% by weight of PbO, 10-15% by weight of B.sub.2 O.sub.3, 0.5-5% by weight of SiO.sub.2, 0-5% by weight of Al.sub.2 O.sub.3, 0-5% by weight of ZnO, 0-15% by weight of PbF.sub.2 and 0-5% by weight of Bi.sub.2 O.sub.3.