ALUMINA FOR TAPE CAST, ALUMINA COMPOSITION, ALUMINA GREEN SHEET, ALUMINA SINTERED PLATE AND ITS PRODUCTION

摘要

PURPOSE: To obtain the subject material homogeneous and high in compact body density and to reduce the camber at the time of sintering and the anisotropy of shrink by using the α-alumina having grain size, shape and grain size distribution in a specific range. ;CONSTITUTION: The α-alumina which has 0.1-5μm number average grain size of primary particles, 23.95g/cm³ true specific gravity of particles, ≥99.90wt.% alumina purity and a short diameter/long diameter ratio of 0.3-1 when shortest diameter of the particles is expressed in terms of short diameter and longest diameter is expressed in terms of long diameter, which is the aggregate of particles having D/H ratio of 0.5-3.0 in the case where the particles has a polyhedron shape, and when the largest grain size parallel to the hexagonal lattice face of the α-alumina being a hexagonal close-packed lattice is expressed in terms of D and grain size perpendicular to the hexagonal lattice face is expressed in terms of H, and which has the relation of D₉₀/D₁₀5 and D₅₀/D₁₀2.5 when the grain size of cumulative 10, 50 and 90% from the particulate side of a grain size distribution are expressed in terms of D₁₀, D₅₀ and D₉₀ is used. A dispersing medium and a binder are added to this alumina to form an alumina green sheet, and this sheet is heated and sintered to form an alumina sintered plate.;COPYRIGHT: (C)1995,JPO