有效减小大细长比微结构电铸层残余应力的兆声辅助微电铸方法  

Megasonic-Assisted Microelectroforming Method to Effectively Reduce the Residual Stress of Large Slender Ratio Microstructure Electroforming Layer

作　　者：杜立群[1,2] 蔡小可 郭柄江 王帅 聂伟荣[3] Du Liqun;Cai Xiaoke;Guo Bingjiang;Wang Shuai;Nie Weirong(State Key Laboratory of High-Performance Precision Manufacturing,School of Mechanical Engineering,Dalian University of Technology,Dalian 116024,China;Key Laboratory for Micro/Nano Technology and System of Liaoning Province,School of Mechanical Engineering,Dalian University of Technology,Dalian 116024,China;School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]大连理工大学机械工程学院高性能精密制造全国重点实验室,辽宁大连116024 [2]大连理工大学机械工程学院辽宁省微纳米技术及系统重点实验室,辽宁大连116024 [3]南京理工大学机械工程学院,南京210094

出　　处：《微纳电子技术》2024年第11期138-146,共9页Micronanoelectronic Technology

基　　金：国家自然科学基金(52375561)。

摘　　要：在利用微电铸工艺制作微机电系统(MEMS)开关的过程中,针对离心保险锁结构因电铸层残余应力大而出现翘曲、扭转等变形问题,采用兆声辅助微电铸方法减小电铸层残余应力。为探究兆声波对电铸层残余应力的影响,基于等效参考温度(ERT)法,建立兆声作用下离心保险锁微结构电铸层残余应力的仿真模型以优选兆声辅助微电铸的工艺参数——兆声功率密度。仿真结果表明,随着兆声功率密度的增大,离心保险锁的残余应力呈现先减小后增大的趋势,当兆声功率密度为2.54 W/cm^(2)时,离心保险锁的最大残余应力为52.58 MPa,相较于无兆声作用时减小了85.4%。在数值模拟的基础上进行微电铸实验验证研究。实验结果表明:兆声功率密度为2.54 W/cm^(2)时,大细长比微结构的变形量减小了88.6%,实验结果与仿真结果一致。在上述仿真结果和实验研究的基础上,制作出了高800μm、细长比高达1∶70的离心保险锁结构,并完成MEMS开关的制作与装配。In the process of fabricating metal microelectromechanical system(MEMS)switches using the microelectroforming process,the residual stress of the electroforming layer was reduced by megatonic assisted microelectroforming method,aiming at the deformation problems(such as warping and torsion)of the centrifugal safety lock structure caused by the large residual stress of the electroforming layer.In order to explore the influence of megasonic on the residual stress of electroforming layer,based on the equivalent reference temperature(ERT)method,the simulation model of the residual stress in the electroforming layer of centrifugal safety lock microstructure under megasonic action was established to optimize the process parameter of megasonic assisted microelectroforming-megasonic power density.Simulation results indicate that with the increase of megasonic power density,the residual stress in the centrifugal safety lock initially decreases first and then increases.When the megasonic power density is 2.54 W/cm^(2),the maximum residual stress of the centrifugal safety lock is 52.57 MPa,reducing by 85.4%compared without megasonic action.The experimental verification of microelectroforming was carried out based on the numerical simulation.Experimental results show that the deformation of large slender ratio microstructure is reduced by 88.6%with the megasonic power density of 2.54 W/cm^(2),which are consistent with the simulation results.Based on the above simulation results and experiment researches,the centrifugal safety lock structure with the height of 800μm and the slender ratio of 1∶70 was fabricated,and the fabrication and assembly of MEMS switch were completed.

关 键 词：兆声 微电铸 残余应力 大细长比微结构 等效参考温度(ERT)法 

分 类 号：TN305[电子电信—物理电子学] TQ153[化学工程—电化学工业]