无引线封装的SOI高温压力传感器设计

Design of SOI high temperature pressure sensor with leadless packaging

为解决高温环境下的压力监测问题,对无引线封装压力传感器进行了研究。首先,对高温压力敏感芯片进行设计,使用绝缘体上硅(SOI)材料提高了敏感芯片的高温稳定性;使用Ti⁃Pt⁃Au复合电极提高了金属电极与硅引线之间欧姆接触的可靠性。使用导电银浆实现敏感芯片电极和基座引脚的电连接,使用玻璃浆料实现芯片与基座的耐高温封装。利用同步热分析仪对导电银浆和玻璃浆料进行了DSC⁃TG同步分析,并借助扫描电镜对其微观形貌进行对比观察,确定其最佳烧结工艺曲线。对封装后的压力传感器进行测试,结果表明:传感器在25~300℃范围内具备优异的性能,综合精度可达0.25%FS。

In order to solve the problem of pressure monitoring in high⁃temperature environments,pressure sensor with leadless packaging is studied.Firstly,high⁃temperature pressure sensitive chip is designed,and the high⁃temperature stability of the sensitive chip is improved by using silicon on insulator(SOI)material;the reliability of the ohmic contact between the metal electrode and the silicon lead is improved by using Ti⁃Pt⁃Au composite electrode.Conductive silver paste is used to realize the electrical connection between the electrodes of the sensitive chip and the base pins,and glass paste is used to realize the high⁃temperature⁃resistant packaging between the chip and the base.Simultaneous DSC⁃TG analysis of the conductive silver paste and glass paste is carried out using a simultaneous thermal analyzer,and the optimal sintering process curves are determined with the help of scanning electron microscope for comparative observation of their microscopic morphology.The packaged pressure sensors are tested,and the results show that the sensors have excellent performance in the range of 25~300℃,with an integrated precision of up to 0.25%FS.