Abstract: There is disclosed a hybrid circuit embodying a crossover formed on a low expansion substrate of aluminum nitride, mullite or a cordierite-type glass-ceramic. The crossover is a thick film dielectric composed of a glass-ceramic having a primary crystal phase of willemite and a secondary phase of cordierite.

Abstract: Metallizing pastes, for forming thick film circuitry on low expansion substrates in electronic devices, are disclosed. The paste contains a glass powder that crystallizes on firing to a glass-ceramic in which lead titanate is the primary crystal phase.

Abstract: This invention relates to the production of glass-ceramic materials particularly suitable for use as substrates in integrated circuit packaging. The inventive glass-ceramics can be prepared from thermally crystallizable glass capable of being concurrently sintered and crystallized in situ at temperatures between about 850.degree.-1000.degree. C. to bodies exhibiting dielectric constants less than about 6, linear coefficients of thermal expansion between about 12-60.times.10.sup.-7 /.degree.C. and containing cordierite solid solution as essentially the sole crystal phase. The glass-ceramics are essentially free from Li.sub.2 O and Na.sub.2 O and consist essentially, expressed in terms of weight percent on the oxide basis of 10-25% MgO+ZnO consisting of 2-18% MgO+0-21% ZnO, 20-38% Al.sub.2 O.sub.3, 40-52% SiO.sub.2, and 2-15% total of at least one oxide in the indicated proportion selected from the group consisting of up to 8% of an alkali metal oxide selected from the group consisting of K.sub.2 O, Rb.sub.

Abstract: This invention is directed to the preparation of two groups of glass-ceramic materials exhibiting properties rendering them especially suitable as substrates for integrated circuit packaging. The first group of materials contains gehlenite, anorthite, and akermanite as the predominant crystal phases and consists essentially, in weight percent of 1-7.25% MgO, 22-40% CaO, 18-36% Al.sub.2 O.sub.3, and 29-42% SiO.sub.2. The second group of materials contains gehlenite, anorthite, and hardystoneite as the predominant crystal phases and consists essentially, in weight percent, of 2-13% ZnO, 22-37.5% CaO, 18-34% Al.sub.2 O.sub.3, and 28-42% SiO.sub.2.

Abstract: This invention is directed to the production of glass-ceramic materials especially designed for substrates in integrated circuit packaging. The glass-ceramics can be prepared from thermally crystallizable glasses that can be sintered into an integral glass-ceramic having a dielectric constant less than 6 and containing willemite as the predominant crystal phase. The overall composition of the glass-ceramic consists essentially, in weight percent of 15-45% ZnO, 10-30% Al.sub.2 O.sub.3, and 30-55% SiO.sub.2. Where desired, a nucleating agent selected from the group consisting of 8-12% ZrO.sub.2 and 0.001-0.05% of a noble metal selected from the group consisting of Au, Pd, and Pt may be included.

Abstract: This invention is directed to the production of glass-ceramic bodies exhibiting high strength and capable of being used at temperatures of 1300.degree. C. and higher. Barium osumilite constitutes the predominant crystal phase and the inventive bodies have overall compositions consisting essentially, in weight percent, of:______________________________________ SiO.sub.2 51-68 Al.sub.2 O.sub.3 17.5-30 MgO 5-12 BaO 3.5-15 Si 0-1 Nb.sub.2 O.sub.5 0-20 Ta.sub.2 O.sub.5 0-10 TiO.sub.2 0-12 ZrO.sub.2 0-6 ______________________________________The bodies can be utilized in monolith form and are very useful as matrices for fiber reinforced structures suitable for high temperature applications.

Abstract: This invention is drawn to thermally devitrifiable sealing glasses capable of forming sound seals with glasses, glass-ceramics, and ceramics having coefficients of thermal expansion (0.degree.-300.degree. C.) between about 0.5-5.times.10.sup.-7 /.degree. C. In finely fritted form, the glasses can be sintered and crystallized in situ at about 900.degree.-1000.degree. C. The glasses consist essentially, expressed in weight percent on the oxide basis, of about 1-2% Li.sub.2 O, 0.7-1.5% MgO, 9-13% ZnO, 19-23% Al.sub.2 O.sub.3, 62-68% SiO.sub.2, and at least 1% K.sub.2 O+Rb.sub.2 O+Cs.sub.2 O in the indicated proportions of 0-3% K.sub.2 O, 0-4% Rb.sub.2 O, and 0-6% Cs.sub.2 O.

Abstract: The subject invention is related to the preparation of ceramic bodies wherein the crystal phase consists essentially of cesium-stuffed, hexagonal cordierite. The bodies are capable of use temperatures up to 1600.degree. C., exhibit nearly isotropic axial thermal expansions, and consist essentially, expressed in weight percent on the oxide basis, of about 11-13% MgO, 34-36% Al.sub.2 O.sub.3, 33-42% SiO.sub.2, and 10-22% Cs.sub.2 O.

Abstract: Small semiconductive devices such as diodes are encapsulated in glass sleeving composed of a PbO--K.sub.2 O--Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --SiO.sub.2 glass exhibiting good alkali durability and specified thermal expansion characteristics in combination with a reduced softening temperature.

Abstract: Sinterable powdered glasses comprising MgO, Al.sub.2 O.sub.3, SiO.sub.2 and at least one modifying oxide selected from the group consisting of BaO, PbO, SrO and CaO, which are thermally-crystallizable at sintering temperatures to yield highly crystalline, low expansion, thermally stable glass-ceramic coatings comprising crystals of a structure corresponding to hexagonal cordierite as the crystal phase, are described. The use of the glasses to provide crystallized electrical barrier layers on glass-ceramic articles is also described.

Abstract: An electrical heating unit of the integral element type, comprising an electrical heating element indirectly bonded to a supporting lithium aluminosilicate glass-ceramic plate, is described. The glass-ceramic plate is provided with a semicrystalline zinc aluminosilicate coating which protects it from the harmful effects of interaction with subsequently applied ceramic and metallic compositions making up the heating element and associated components.

Abstract: This invention relates to sealing mixtures consisting essentially of a sealing glass having a low sealing temperature and a high coefficient of thermal expansion, and a glass-ceramic additive that imparts a lower effective coefficient of expansion to the sealing mixture with a minimum effect on glass flow at the sealing temperature. It further concerns the use of this mixture to produce fusion seals between elements, particularly elements in electrical and electronic components.