| 摘要 |
PURPOSE:To provide a composition for a low-temperature baked substrate capable of conducting simultaneous baking with a low-resistance conductor, similar in thermal expansion coefficient to highly thermally conductive materials and intended to improve the mechanical strength of the baked products thereof, comprising glass powder of specific composition and an inorganic filler. CONSTITUTION:The composition comprising (A) 80.0-99.9wt.% of glass powder 2-5mum in mean particle diameter, depositing mullite as the main crystal phase on heat treatment, composed of (1) 45-58wt.% of Al2O3, (2) 20-35wt.% of SiO2, (3) 5-15wt.% of B2O3, (4) 5-20wt.% of MgO and (5) 0-4wt.% of an alkali metal oxide and (B) 0.1-20.0wt.% of an inorganic filler >=1.4m<2>/g in specific surface area on average, acting as an external nucleating agent for depositing cordierite, consisting of at least one kind selected from oxides like Al2O3, SiO2 and MgO and oxides of niobium, tantalum and rare earth metals, etc., and/or compounds giving such oxides on heat treatment. The other objective substrate can be obtained by molding and baking this composition. This substrate has the following characteristics: (1) having both mullite and cordierite crystal phases; (2) thermal expansion coefficient: 30-55X10<-7>/ deg.C; and (3) breaking strength: >=23kgf/mm<2>. |
