Alumina陶瓷，造成很冷敷

Item test condition Unit and Symbolic corundum-mullitep orcelain A3S2-2 A-75 A-95 A-96 A-99 volume density G/cm3 ≥2.80≥3.20≥3.60≥3.70≥3.70Air tightness ——passpasspassLiquid permeability passpasspasspasspassFlexural strength Mpa≥100≥200≥280≥280≥300linear expansion coefficient 20 100°C×10-6/°C≤8≤6———20 500°C×10-6/°C——6.5 7.56.5 7.56.5 7.520 800°C×10-6/°C——6.5 86.5 86.5 8Flexural strength 1MHz 20°C≤≤9 109 109 10.5500°C——9 109 10—10GHz20°C——9 109 109 10.5the tangent of its dielectric loss angle 1MHz 20°C×10-4≤20≤10≤4≤4≤2.5500°C×10-4——30 4030 40—10GHz20°C×10-4——≤10≤10≤6Volume resistivity 100°CΩ.cm≥1012≥1012≥1013≥1013≥1013300°CΩ.cm——≥1010≥1010≥1010500°CΩ.cm——≥108≥108≥109Thermal shock resistance ——passpasspassBreakdown Strength kV/mm≥15≥20≥18≥15≥15Chemical stability 1:9HCImg/cm2——≤7.0≤7.0≤0.710%NaOHmg/cm2——≤0.2≤0.2≤0.1grain Size μm——15 30——application Mainly used for large device porcelain usedfor High mechanical strength device or part shell and electronic substrate Causing coldness substrate shell and electronic substrate Properties of alumina ceramics