碱金属氧化物对硼硅酸盐系玻璃/Al_2O_3材料性能的影响

Effect of alkalis on properties of borosilicate glass/ Al_2O_3 system material

以硼硅酸盐系玻璃和Al2O3粉料为原料，采用低温烧结法制备了玻璃／Al2O3系LTCC材料。设计玻璃中碱金属氧化物的质量分数为0～6％，研究了碱金属氧化物添加量和烧成温度对玻璃，Al2O3材料的烧结性能、热性能、介电性能和力学性能的影响。随着碱金属氧化物含量增加，玻璃／Al2O3材料的体积密度、相对介电常数、抗弯强度增加，而介电损耗恶化。当碱金属氧化物添加的质量分数为2％，材料于875℃烧结良好，显示出优异的性能：体积密度为2．84g／cm^3，相对介电常数7．71，介电损耗1．15×10^-3（于10MHz下测试），抗弯强度为158MPa，热导率为2．65W／（m·℃），线膨胀系数为7．77×10^-6/℃。

Borosilicate glass/Al2O3 system LTCC materials were prepared with borosilicate glass and Al2O3powder using low-temperature sintering method. The effects of alkalis （Na2O＋K2O＋LiO2） contents and sintering temperature on sintering, thermal, dielectric and strength properties of the glass/Al2O3 materials were investigated through modifying alkalis content in the glass from 0 to 6%（mass fraction）. With the increase of alkalis content in the materials, corresponding increases are found in bulk density, εr and three-point bending strength of the materials, while their dielectric loss get bad. By contrast, the material with 2%（mass fraction） alkalis exhibits better properties of bulk density p=2.84 g/cm3,εr=7.71, dielectric loss tanδ=1.15× 10^-3（at 10 MHz）, bending strength σ= 158 MPa, thermal conductivity 2=2.65 W/（m. ℃）, thermal expansion coefficient at = 7.77 ×10^-6/℃, sintered at 875 ℃.