POWDERY RAW MATERIAL FOR CERAMIC MULTILAYERED CIRCUIT BOARD AND CRYSTALLITE CERAMIC MULTILAYERED CIRCUIT BOARD

摘要

PURPOSE:To make shrinkage in firing isotropic and improve dimensional accuracy by incorporating an aluminum component, a silicon component and an alkaline earth metal component. CONSTITUTION:The powdery ceramic raw material containing 50-60wt.% aluminum component, 50-40wt.% silicon component (expressed in terms of silica) and 0.3-1.5wt.% mullite crystal (expressed in terms of alkaline earth metal oxide) is obtained by mixing a mullite sol mixture obtained by mixing at least an alumina sol with a silica sol with the alkaline earth metal, spraying them into an atmosphere of 1300-1500 deg.C and drying them, A green sheet is obtained by molding a slurry obtained by mixing the powdery raw material with the ceramic powder containing alumina and an additive containing a binder. After a conductive wiring is formed on the green sheet, a ceramic sintered compact is obtained by sintering the green sheet at 1500-1700 deg.C.