微机电系统传感器深孔封装结构分析

Analysis of Deep Hole Packaging Structure for Microelectromechanical System Sensors

为解决MEMS传感器在封装或使用过程中材料之间热匹配不良、应力集中问题,基于提出的微机电系统传感器阶梯深孔封装工艺对芯片进行封装,并运用数值模拟手段,对模块的可靠性进行分析,研究模块的温度应力和温度位移的变化规律。研究结果表明,提出的微机电系统传感器阶梯深孔封装工艺是在石英基板的内部设置阶梯状的孔洞,并与芯片内部的孔洞对齐后,采用金丝键合工艺连接将石英基板与芯片连接,并运用双组份加成型灌封胶填充固化和释放压力的目的;两种封装方式的位移曲线、应力曲线均随着温度荷载的周期性波动而波动,且应力极值不断放大,传统LCC封装工艺的芯片位移、应力明显大于阶梯深孔封装的芯片位移、应力,后者位移约为前者位移的19%~27%,后者应力约为前者应力的18%~57%,表明阶梯深孔封装结构有效改善了模块内部组件的翘曲和应力集中现象。

In order to solve the problems of poor thermal matching and stress concentration between materials during the packaging or use of MEMS sensors,the chip was packaged based on the proposed step deep hole packaging process for MEMS sensors.Numerical simulation methods were used to analyze the reliability of the module and study the changes in temperature stress and temperature displacement of the module.The research results indicate that the proposed step deep hole packaging process for MEMS sensors involves setting step shaped holes inside the quartz substrate and aligning them with the holes inside the chip.The quartz substrate is connected to the chip using a gold wire bonding process,and a dual component addition molding potting adhesive is used to fill,cure,and release pressure;The displacement and stress curves of both packaging methods fluctuate with the periodic fluctuations of temperature load,and the extreme stress values continue to amplify.The displacement and stress of chips in traditional LCC packaging process are significantly greater than those in stepped deep hole packaging,with the latter displacement being about 19%~27%of the former displacement and the latter stress being about 18%~57%of the former stress,This indicates that the stepped deep hole packaging structure effectively improves the warping and stress concentration of internal components in the module.