| 摘要 |
This low-expansion glass comprises, in mol%, 55 to 75% of SiO2, 5 to 17% of B2O3, 5 to 15% of Al2O3, 0 to 10% of MgO, 0 to 10% of CaO, 0 to 5% of SrO, 0 to 1% of BaO, 0 to 6% of ZnO, 0.6 to 4% of Li2O, 0 to 1% of Na2O, 0 to 1% of K2O, 0 to 1% of SnO2, 0 to 5% of Fe2O3, 0 to 30% of TiO2 and 0 to 10% of CeO2. The total content of alkali metal oxides is up to 5mol%, while the content of Li2O exceeds the total content of alkali metal oxides other than Li2O, each content being expressed in terms of mol%. Further, the low-expansion glass exhibits a dielectric loss tangent of less than 0.0050 as determined under the condition of 25°C and 1GHz. |
