Abstract: Starting mixture for an insulating composition, silk-screening ink comprising such a mixture, and the use of said ink for the manufacture of hybrid microcircuits on colaminated sustrates.The invention relates to the formulation of a starting mixture for an insulating composition, comprising a vitreous phase and several ceramic phases in the respective ratios by volume for the vitreous phase between 85 and 60% and for the ceramic phases between 15 and 40%, the vitreous phase being a silicate of zinc and alkaline earth.According to an embodiment of the invention the starting mixture is remarkable in that the vitreous phase is constituted by the molar ratios of the following oxides:30 to 55% of silicon (SiO.sub.2), 15 to 30% of zinc oxide (ZnO), 0 to 20% of boric anhydride (B.sub.2 O.sub.3), 0 to 10% of alumina (Al.sub.2 O.sub.3), 15 to 40% of barium oxide (BaO), and in that the ceramic phases are constituted by the ratios by volume of the following oxides: 0 to 10% of cobalt oxide (Co.sub.3 O.sub.

Abstract: The invention relates to starting mixtures for an insulating composition comprising (a) a from about 70 to 80% by volume of vitreous phase comprising Al.sub.2 O.sub.3, SiO.sub.2, B.sub.2 O.sub.3, PbO, ZnO, CaO, and CuO and (b) from about 30 to 20% by volume of at least one oxide of lead having an oxidation degree of at least two, in powder form. The starting mixtures are useful in silk-screening inks for hybrid microcircuits.

Abstract: The invention relates to luminescent screen comprising an optical fibre plate formed by the reunion of elementary optical fibres constituted by bars of core glass (10) enveloped by a cladding glass (12), the optical fibre plate being provided with cavities obtained after having hollowed out partially the core glass. The bottom of the cavities is covered by a deposit of a restoring material (30) which is transparent to the luminous flux, improving the surface state and the flatness of the bottom of the cavities and tending to minimize the break (32) at the intersection between the bottom and the wall of each cavity. The restoring material preferably has an optical index near that of the core glass in order to ensure the optical continuity. Said screen of high resolution and high luminous efficiency is used in display tubes such as night-vision tubes, X-ray converter tubes, slid scanning tubes, cathode ray tubes used in oscilloscopy or in television.

Abstract: The invention relates to a silk screen printing paste which is provided according to the thick-layer technique and is to be fired in a non-oxidizing atmosphere and which comprises a mixture of a vitreous passive component and a permanent binder, an active component and a temporary binder, characterized in that it also comprises one or more lead oxide(s) having a degree of oxidation higher than 2 in a quantity below 20% by volume.The invention also relates to hybrid circuits manufactured by means of said paste.Application: hybrid micro-circuits.

Abstract: The invention relates to the formulation of a starting mixture for an insulating composition, comprising a vitreous phase and several ceramic phases in the respective ratios by volume for the vitreous phase between 85 and 60% and for the ceramic phases between 15 and 40%, the vitreous phase being a silicate of zinc and alkaline earth.According to an embodiment of the invention the starting mixture is remarkable in that the vitreous phase is constituted by the molar ratios of the following oxides:30 to 55% of silicon (SiO.sub.2), 15 to 30% of zinc oxide (ZnO), 0 to 20% of boric anhydride (B.sub.2 O.sub.3), 0 to 10% of alumina (Al.sub.2 O.sub.3), 15 to 40% of barium oxide (BaO), and in that the ceramic phases are constituted by the ratios by volume of the following oxides: 0 to 10% of cobalt oxide (Co.sub.3 O.sub.4), 5 to 20% of zinc oxide (ZnO), and 10 to 25% of lead oxide (PbO.sub.2).Application: Manufacture of microcircuits on colaminated metallic substrates.

Abstract: Dielectric composition, screen printing paste having such a composition and products obtained.The invention describes a dielectric composition which may be used in particular as an insulating screen-printing paste, which is compatible with a copper-containing conductive screen-printed layer, the paste containing, dispersed in an organic vehicle, a mixture of ceramic phases, consisting essentially of zinc oxide and cobalt oxide, and a vitreous phase containing at least a glass which can be devitrified by dissolving the zinc oxide.

Abstract: A dielectric composition which may be used as an insulating silk-screening paste and is compatible with a copper-containing conductive silk-screened layer, such as used in multilayer circuit boards. The paste includes an organic carrier, a mixture of aluminum oxide, and one or more types of glass of the "short" type, of which at least one glass can be devitrified by dissolution of the aluminum oxide.