硅微谐振式加速度计器件级封装应力辨识  

Chip-Level Packaging Stress Identification for Micromechanical Silicon Resonant Accelerometer

作　　者：贡旭超 裘安萍[1] 黄锦阳 施芹[1] Gong Xuchao;Qiu Anping;Huang Jinyang;Shi Qin(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学机械工程学院,南京210094

出　　处：《半导体技术》2022年第5期410-415,共6页Semiconductor Technology

基　　金：国家自然科学基金资助项目(62074078)。

摘　　要：器件级封装应力是影响微电子机械系统(MEMS)器件性能的主要因素之一。基于硅微谐振式加速度计(SRA)的力频特性,结合SRA芯片表面翘曲变化的有限元分析,实现SRA器件级封装应力的辨识。分析封装应力的辨识机理和误差,建立SRA器件级封装应力仿真模型,通过谐振器频率变化与基于芯片翘曲变化的有限元仿真进行相互验证,完成两种封装应力表征的统一辨识。以此为基础,对不同封装参数的SRA进行应力辨识。采用谐振器频率变化表征封装应力的测试结果与仿真结果相吻合。结果表明随着金锡焊层直径的增大,封装应力随之增大,金锡焊层直径为1.5、3.0和4.0 mm对应封装应力分别为1.45、2.31和3.42 MPa。提出的SRA器件级封装应力的实时应力辨识方法可满足快速批量化应力辨识的要求。Chip-level packaging stress is one of the main factors affecting the performances of micro-electro-mechanical system(MEMS)devices.Based on the force-frequency characteristics of the micromechanical silicon resonant accelerometer(SRA),combined with the finite element analysis of the surface warpage change of the SRA chip,the purpose of chip-level packaging stress identification for the SRA was achieved.The identification mechanism and error of packaging stress were analyzed and the simulation model of the SRA chip-level packaging stress was established,which leads to the unification of two kinds of stress characterization in packaging stress identification by the mutual verification between the frequency change of the resonator and the finite element simulation based on the warpage change of the chip.According to the identification method,the chip-level packaging stresses in SRAs with different packaging parameters were identified.The packaging stresss characterized using the resonator frequency variation is in good agreement with the simulation results.The results demonstrate that the packaging stress increases with the diameter of AuSn solder layer.The AuSn solder layers with the diameters of 1.5,3.0 and 4.0 mm correspond to packaging stresses of 1.45,2.31 and 3.42 MPa,respectively.The proposed real-time stress identification method for chip-level packaging stress of SRAs can meet the requirement for rapid batch stress identification.

关 键 词：微电子机械系统(MEMS) 硅微谐振式加速度计(SRA) 器件级封装应力 封装应力辨识 有限元仿真 

分 类 号：TN305.94[电子电信—物理电子学] TH824.4[机械工程—仪器科学与技术]