MEMS陀螺芯片的晶圆级真空封装  

Wafer-level vacuum packaging for MEMS gyroscope chips

作　　者：刘福民[1] 张乐民 张树伟 刘宇[1] 王学锋[1] LIU Fumin;ZHANG Lemin;ZHANG Shuwei;LIU Yu;WANG Xuefeng(Beijing Institute of Aerospace Control Devices,Beijing 100039,China)

机构地区：[1]北京航天控制仪器研究所,北京100039

出　　处：《传感器与微系统》2022年第1期15-18,23,共5页Transducer and Microsystem Technologies

摘　　要：微机电系统(MEMS)陀螺需要真空封装以确保其检测精度,晶圆级真空封装可以使MEMS微结构避免芯片切割过程中的粘连以及颗粒污染,提高芯片的成品率。为实现MEMS陀螺芯片的晶圆级真空封装,提出了一种全硅MEMS陀螺芯片的晶圆级真空封装结构方案,并突破了Si-SiO_(2)直接键合、吸气剂制备、金-硅(Au-Si)键合等关键技术,实现了MEMS芯片的晶圆级真空封装。Si-SiO_(2)直接键合和Au-Si共晶键合的剪切强度分别达到了56.5 MPa和35.5 MPa,表明晶圆级封装中晶圆键合强度满足晶圆级真空封装的需要。晶圆级真空封装实现陀螺仪谐振最大Q值为103879,对应的真空压力为2 Pa左右,陀螺仪芯片已达到MEMS陀螺工程化的需要。Vacuum encapsulation is needed for micro-electro-mechanical system(MEMS)gyroscopes to ensure their detecting precision,wafer-level vacuum packaging can avoid adhesion and particle contamination during chip dicing and improve the yield.In order to realize MEMS gyroscope packaging in wafer level,a wafer-level vacuum packaging scheme is proposed.Key technologies such as Si-SiO_(2) direct bonding,getter preparation and Au-Si bonding are broken through,and MEMS gyroscope chips packaging in wafer-level are realized.The shear strengths for Si-SiO_(2) bonding and Au-Si eutectic bonding are measured to be as high as 56.5 MPa and 35.5 MPa,respectively,indicating wafer bonding strength meet the need for wafer-level packaging.The maximum Q value of 103879 of the gyroscope resonance structure is achieved,corresponding to a vacuum pressure of 2 Pa by wafer-level vacuum packaging.The chips have met the needs for engineering applications of MEMS gyroscopes.

关 键 词：晶圆级真空封装 微机电系统陀螺仪 硅-二氧化硅直接键合 金-硅键合 吸气剂 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TN305.94[自动化与计算机技术—控制科学与工程]