| 摘要 |
PURPOSE:To provide the composition having excellent flexural strength, low permittivity, and the thermal expansion coefficient approximating that of an Si chip by forming the composition from the specified amts. of Al2O3, SiO2, PbO, B2O3, an alkaline-earth metal oxide, and the oxide of (Ti+Zr+Hf). CONSTITUTION:The composition and substrate contain, by weight expressed in terms of oxides, 60-91% Al2O3, 5-30% SiO2, 3-20% PbO, 0.5-15% B2O3, 0.5-15% alkaline-earth metal oxide, and 0-0.008% oxide of (Ti+Zr+Hf). Since the reactivity between the substrate and the surface conductor is increased at less than the lower limit of Al2O3 in the composition, the solder wettability of the conductor is deteriorated, and the flexural strength is increased as the Al2O3 content increases. The permittivity is increased at more than the upper limit. At less than the lower limit of SiO2, the composition is hardly sintered, and the flexural strength is lowered at more than the upper limit. At less than the lower limit of PbO, the composition imperfectly sintered, and the permittivity is increased at more than the upper limit. At less than the lower limit of B2O3, the fluxing effect is eliminated, and the water resistance is deteriorated at more than the upper limit. The alkaline-eaeth metal oxide behaves in the same way as PbO. |
