硅-蓝宝石绝压传感器陶瓷密封结构设计与分析

Design and analysis of ceramic sealed structure of silicon-on-sapphire absolute pressure sensor

介绍了硅-蓝宝石绝压传感器中氧化铝陶瓷-钛合金的真空密封参考腔小型化结构设计,探讨了异质材料不匹配引起的陶瓷断裂问题,对陶瓷-钛合金封装结构的应力情况进行了计算和分析,通过中间缓冲层设计、减小陶瓷承受的结构残余应力,消除了由陶瓷断裂导致的密封失效;选择热胀系数相近的可伐中间层材料,对比不同厚度缓冲层产生的残余应力,优化中间层结构,采用LTCC加工技术与真空钎焊工艺结合制作了陶瓷-可伐-钛合金密封组件,并通过了高、低温度试验考核:组件密封漏率小于1×10^(-10)Pa·m^3/s,密封可靠,满足绝压传感器使用寿命的要求。

The minimized structure design of alumina ceramic-titanium alloy vacuum sealed reference cavity in silicon-on sapphire（ SOS） absolute pressure sensor is introduced. The problem of ceramic fracture caused by mismatch of heterogeneous material is discussed. The stress situation of ceramic-titanium alloy packaging structure is calculated and analyzed. The residual stress of ceramic structure is reduced through the design of intermediate buffer layer,the ceramic seal failure caused by ceramic breakage is removed. Kovar material with the similar thermal expansion coefficient is selected as the middle layer. The middle layer structure is optimized by comparing the residual stress generated by the different thickness buffer layer. LTCC processing technology and vacuum brazing process are used to make the ceramic-kovar-titanium alloy sealing components. The component passes the high and low temperature test,and the leaking rate is less than 1 × 10^（-10）Pa· m^3/s,it is sealed and reliable,which meets the life requirement of working life of the absolute pressure sensor.