WO3对零膨胀锂铝硅封接玻璃流动性的影响与作用机理

密封连接石英玻璃被广泛应用于航空航天、半导体加工以及微机电系统真空连接等领域。改进的低膨胀Li₂O-Al₂O₃-SiO₂(LAS)系微晶玻璃可以用于封接石英玻璃,但存在流动性不佳的难题。本文通过掺入WO₃对LAS系微晶玻璃进行改性,利用线膨胀系数分析仪、差示扫描量热仪、X射线衍射仪、高温烧结影像仪、扫描电镜,研究了掺入WO₃后LAS玻璃封接石英玻璃的机理。结果表明:WO₃对LAS玻璃的析晶产生先增强后削弱的影响; WO₃掺量越大,热膨胀系数越大,当掺量达到5.0%(质量分数)时,热膨胀系数提升至5.69×10^-7 ℃^-1;流动性与润湿性随着掺量增加而提升,铺展面积随掺量增加而增大,润湿角随掺量增加而减小,有效改善了LAS玻璃本身流动性不足的问题;LAS玻璃与石英玻璃之间主要是通过化学元素迁移实现封接。

Effect and Mechanism of WO3 on Fluidity of Zero Expansion Lithium Aluminum Silicon Sealing Glass

Sealing connection quartz glass is widely used in aerospace, semiconductor processing and micro-electro-mechanical system vacuum connection, etc. The improved low-expansion Li₂O-Al₂O₃-SiO₂ (LAS) glass-ceramics can be used to seal quartz glass, but there is a problem of poor fluidity.LAS glass-ceramics were modified by incorporating WO₃. The mechanism of LAS glass sealing quartz glass after incorporating WO₃ was investigated by using linear expansion coefficient analyzer, differential scanning calorimeter, X-ray diffractometer, high temperature sintering imager and scanning electron microscope. The results show that the effect of WO₃ on the crystallization of LAS glass is strengthening first and then weakening. The more WO₃ is added, the greater the thermal expansion coefficient is. When the amount of WO₃ reaches 5.0% (mass fraction), the thermal expansion coefficient increases to 5.69×10^-7 ℃^-1.The fluidity and wettability develop with the enlarge of the external doping amount. The spreading area extends with the increase of the external doping amount. The wetting angle decreases with the expand of the external doping amount, which effectively improves the problem of insufficient fluidity of LAS glass itself. The sealing between LAS glass and quartz glass is mainly achieved by the migration of chemical elements.