摘要
环境温度变化造成的热应力是影响MEMS加速度计性能的关键因素。为了提升MEMS加速度计温度稳定性,以蝶翼式MEMS加速度计为研究对象,分别在敏感芯片上设计应力释放结构和敏感芯片与陶瓷基底之间设计应力隔离结构。利用有限元分析工具COMSOL对有无应力释放和隔离结构的情况进行了对比仿真,结果表明敏感单元上的敏感梁应用应力释放结构只有原结构最大应力水平的0.3%,封装时采用应力隔离结构间接连接比原直接连接方式最大应力下降一个数量级。采用微机械加工技术和微电子工艺技术结合的MEMS加工工艺实现含应力隔离结构的加速度计原理样机制作。对样机进行温度测试,试验结果表明有应力释放与隔离结构在-40°C~60°C区间的漂移量比无应力释放与隔离结构提升约3.5倍,验证了应力释放与隔离结构对温度稳定性提升的有效性,研究结果可以为加速度计在高性能、恶劣环境下的应用提供参考。
Thermal stress caused by changes in ambient temperature is a key factor affecting the performance of MEMS accelerometers.In order to improve the temperature stability of MEMS accelerometers,the stress release structure on sensitive chips and stress isolation structure between sensitive chips and ceramic substrates are designed with butterfly MEMS accelerometers as the research objects.Using the finite element analysis tool COMSOL,the situation of stress release and isolation structure is compared and simulated,and the results show that the stress release structure of the sensitive beam application on the sensitive unit is only 0.3%of the maximum stress level of the original structure,and the maximum stress of indirect connection with stress isolation structure decreases by an order of magnitude compared with that of original direct connection when encapsulating.The MEMS fabrication process combining micromachining technology and microelectronic process technology is used to produce the principle prototype of the accelerometer with stress isolation structure.The temperature test of the prototype is carried out,and the test results show that the drift of the stress release and isolation structure in the range of-40°C~60°C is about 3.5 times higher than that of the stress-free release and isolation structure,which verified the effectiveness of the stress release and isolation structure on the improvement of temperature stability,and the research results could provide a reference for the application of accelerometers in high-performance and harsh environments.
作者
蒲金飞
侯占强
虢晓双
曾承志
肖定邦
吴学忠
PU Jinfei;HOU Zhanqiang;GUO Xiaoshuang;ZENG Chengzhi;XIAO Dingbang;WU Xuezhong(College of Intelligence Science and Engineering,National University of Defense Technology,Changsha 410073,China;Hunan eNavigate Technology Co Ltd,Changsha 410100,China;Tangzhi Science&Technology Hunan Development Co Ltd,Changsha 410007,China)
出处
《中国惯性技术学报》
EI
CSCD
北大核心
2022年第2期235-239,共5页
Journal of Chinese Inertial Technology
基金
国家自然科学基金项目(62104258)。
