Corning Glass Works

John F MacDowell

George Halsey Beall

Mark P Taylor

Hermann L Rittler

Robert John Paisley

This invention is directed to the preparation of glass-ceramic materials especially suitable for use in multilayer substrates for integrated circuit packages. The inventive glass-ceramics are derived from thermally crystallizable glass which, in the form of frit, are capable of being sintered into an integral body at temperatures below 1000.degree. C. and essentially concurrently crystallized in situ to yield BPO.sub.4 as the predominant crystal phase. The inventive glass-ceramics exhibit a linear coefficient of thermal expansion between about 30-45.times.10.sup.-7 /.degree.C., a dielectric constant less than 5, and consist essentially, in weight percent, of 10-25% B.sub.2 O.sub.3, 20-40% P.sub.2 O.sub.5, and &gt;50-65% SiO.sub.2.

Glass-ceramic substrates for electronic packaging

The present invention is concerned with the preparation of glass microfoams and gas-ceramics having compositions selected from the systems of SiO.sub.2 --Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --RO--R.sub.2 O, SiO.sub.2 --Al.sub.2 O.sub.3 (B.sub.2 O.sub.3)--P.sub.2 O.sub.5 --Li.sub.2 O--[ZrO.sub.2 (TiO.sub.2)], and SiO.sub.2 --P.sub.2 O.sub.5 --B.sub.2 O.sub.3 --[RO], wherein RO is selected from the group of MgO, CaO, SrO, BaO, and ZnO, and R.sub.2 O is selected from the group of alkali metal oxides. The foams comprise hydrogen-containing cells produced through the inclusion in the batch of a hydrogen-generating agent selected from the group of ammonium salts and/or a combination of amines and/or carbohydrates and/or hydrocarbons with phosphates.

Hydrogen-containing glass microfoams and gas-ceramics

This invention relates to the preparation of hydraulic cements consisting essentially of glasses having compositions within area ABCDEA of FIG. 1 which, when contacted with water, hydrate to form strong, low porosity cements having crystals composed predominantly of hydrogarnet solid solution and/or hydrogehlenite.

CaO-Al.sub.2 O.sub.3 -SiO.sub.2 glass hydraulic cements

This invention is directed to the production of transparent, translucent, or opaque glass-ceramic articles containing BPO.sub.4 as the predominant crystal phase by heat treating precursor glass articles consisting essentially, expressed in terms of weight percent on the oxide basis, of about:

B.sub.2 O.sub.3 --P.sub.2 O.sub.5 --SiO.sub.2 glass-ceramics

This invention is concerned with the production of substantially transparent glass-ceramic articles containing mullite as the predominant crystal phase which can be prepared by crystallizing in situ precursor glasses capable of being melted at temperatures no higher than 1650.degree. C. The inventive articles consist essentially, in weight percent, of 10-70% SiO.sub.2, 7-40% B.sub.2 O.sub.3, 14-50% Al.sub.2 O.sub.3, 0-35% RO, wherein RO consists of at least one member of the group in the indicated proportions of 0-15% MgO, 0-20% CaO, 0-30% SrO, 0-30% BaO, and 0-30% PbO, and 0-30% R.sub.2 O, wherein R.sub.2 O consists of at least one member of the group in the indicated proportions of 0-10% Li.sub.2 O, 0-15% Na.sub.2 O, 0-25% K.sub.2 O, 0-25% Rb.sub.2 O, and 0-25% Cs.sub.2 O, the mole ratio Al.sub.2 O.sub.3 :RO+R.sub.2 O&gt;1.3. Where 0.01-1% Cr.sub.2 O.sub.3 is included in the composition, the glass-ceramic will exhibit broad absorption over the visible region of the radiation spectrum, strong fluorescence in the red and near infrared portions of the spectrum where exposed to ultraviolet and/or visible radiation, and relatively little overlap of the absorption and fluorescent spectra.

Transparent glass-ceramics containing mullite

This invention is concerned with the production of substantially transparent glass-ceramic articles containing mullite as the predominant crystal phase which can be prepared by crystallizing in situ precursor glasses capable of being melted at temperatures no higher than 1650.degree. C. The inventive articles consist essentially, in weight percent, of 1070% SiO.sub.2, 7-40% B.sub.2 O.sub.3, 14-50% Al.sub.2 O.sub.3, 0-35% RO, wherein RO consists of at least one member of the group in the indicated proportions of 015% MgO, 0-20% CaO, 0-30% SrO, 0-30% BaO, and 0-30% PbO, and 0-30% R.sub.2 O, wherein R.sub.2 O consists of at least one member of the group in the indicated proportions of 0-10% Li.sub.2 O, 0-15% Na.sub.2 O, 0-25% K.sub.2 O, 0-25% Rb.sub.2 O, and 0-25% Cs.sub.2 O, the mole ratio Al.sub.2 O.sub.3 :RO+R.sub.2 O&gt;1.3. Where 0.01-1% Cr.sub.2 O.sub.3 is included in the composition, the glass-ceramic will exhibit broad absorption over the visible region of the radiation spectrum, strong fluorescence in the red and near infrared portions of the spectrum where exposed to ultraviolet and/or visible radiation, and relatively little overlap of the absorption and fluorescent spectra.

Composite materials consisting of a matrix incorporating high-aspect-ratio reinforcement members, wherein the reinforcement members consist of relatively large, prestressed glass or glass-ceramic members, such as macrofilaments or rods having diameters in excess of about 0.010 inches, are described.

Macrofilament-reinforced composites

There are disclosed glass-ceramic materials characterized by a nepheline crystal phase and optionally having a secondary celsian or hexacelsian crystal phase. In addition to the SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O, and TiO.sub.2 as a nucleating agent, the materials contain K.sub.2 O and/or Li.sub.2 O in limited amount, and preferably also contain BaO. These additives provide microwave compatibility, a thermal coefficient of expansion below 95.times.10.sup.-7 /.degree.C., and suitability for application as glazed table or ovenware.

Microwave-compatible nepheline glass-ceramics

The instant invention is concerned with a unique method for crystallizing glass bodies into glass-ceramic articles. More particularly, this invention is drawn to a method whereby glass-ceramic articles can be formed without cooling the precursor glass below the transformation range thereof. Thus, the glass melt is cooled and formed into a vitreous body. This vitreous body is cooled to a temperature no lower than about 25.degree.-250.degree. C. above the transformation range where nucleation is developed therewithin. Essentially immediately thereafter, the nucleated body is exposed to a temperature between about 100.degree.-500.degree. C. higher than that of the nucleation step to cause the growth of crystals on the nuclei. The process significantly expedites the production of glass-ceramic articles and substantially reduces energy consumption from the forming stage to the finished product.

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Painted Post, NY, United States of America

John F MacDowell