低g值MEMS惯性开关的设计与工艺优化

摘要

The available low-g silicon-based MEMS inertial switch has such disadvantages as complicated fabrication process, long fabrication period, low rate of qualified products, etc. To solve this problem, new structure design and fabrication process were proposed, which include: using cylinder shaped proof mass with circular shaped spiral spring as sensing structure; developing a new anodic boding process to realize glass-SOI-glass direct bonding; and modifying the fixed electrodes position to solve the isolating problem. Based on these considerations, an optimized fabrication process was proposed and implemented, and its experiment results show that the fabrication yield reaches 4 times as high as that of the previous design. The centrifugal experiment results show that the threshold value of the MEMS switch is around 5.6g, which meets is the designed requirement of 5.5g±1g.%针对既有硅基低g值MEMS惯性开关的加工工艺复杂、加工周期长以及成品率低的问题，提出改进的结构设计和工艺方案。设计以圆形质量块+圆形螺旋梁为基础的敏感结构，以避免原结构因应力集中导致的螺旋梁断裂现象；提出玻璃-SOI-玻璃三层直接键合工艺技术，改变金属电极间绝缘设计方法，调整开关行程的加工方式，从而减少大量加工工序，降低了工艺难度。形成了一种可靠、简单的低g值开关的统一化加工方案。流片结果表明，新研制的MEMS开关的加工周期缩短为原来的1/3，加工成品率提高为原来的4倍。测试结果表明，开关阈值为5.6g，符合设计要求的5.5g±1g。