基于自停止腐蚀技术的H型谐振式微机械压力传感器

摘要

为了提高压力传感器的精度并抑制温漂,提出了一种基于自停止腐蚀技术的“H”型双端固支梁、电磁激励、差分检测的微机械(MEMS)谐振式压力传感器.首先,通过有限元分析仿真优化了传感器的机械参数,得到了较高的灵敏度和分辨率.然后,基于浓硼扩散自停止腐蚀原理,采用MEMS体硅标准工艺加工出一致性较好的传感器样品.最后,采用非光敏BCB,在真空高温高压条件下将硅片与谐振器黏和键合完成了传感器的真空封装,并设计了应力隔离的后封装方法以降低温漂.实验结果表明:传感器的检测范围为0～120 kPa,满量程非线性度低于0.02 ％,准确度达到0.05％ FS,加入应力隔离后在-40～70℃的温度漂移不高于0.05％/℃.该传感器能够实现大量程高精度的压力测量,有效地抑制了温漂,具有较高的性能指标.%In order to increase accuracy and reduce temperature drifts of pressure sensors, a micro-machined resonant pressure sensor with H-type doubly-clamped lateral beams was proposed based on electromagnetically driving and differential detection. First, Finite Element Method(FEM) analysis was performed to guarantee the sensitivity and the resolution of the sensor. Then, based on the boron-diffusion self-stopped etch technique, a sensor sample with good uniformity was achieved by a standard bulk Micro-electro-mechanical System(MEMS) process. Finally, the vacuum package of the sensor was accomplished by adhesive bonding using non-photosensitive BCB(Benzocy-clobutene,DVS-BCB-3022-46) and stress isolation. Experimental results show that the nonlinearity is lower than 0. 02% in 0 to 120 kPa with a accuracy of 0. 05% FS, and the temperature drift is less than 0. 05%/℃ in -40 ℃ to 70 ℃. The sensor can suppress temperature drifts and realize pressure measurement in wide measuring range and higher precision.