多梁结构压阻式测振加速度传感器

Multi-Flexure Piezoresistive Accelerometer for Vibration Detection

为满足制造装备智能化发展对测振传感器的需求,针对常见加速度传感器在性能、成本和微型化上的不足,研制了一种基于微机电系统技术的多梁结构压阻式加速度传感器。通过将2根短小敏感梁引入传统双桥结构的方式,在提升固有频率的同时,保证了传感器仍具有较高的测量灵敏度。利用敏感梁上的最大应力和结构固有频率相乘的结果作为性能评价标准,结合梁变形理论和实际工艺条件确定了传感器的结构尺寸。采用硅材料刻蚀、硼离子注入、溅射金属铝及阳极键合等工艺,制作了传感器芯片。实验结果表明,所研制的加速度传感器能够准确测量不同频率下的加速度信号,在每g下的灵敏度达到了0.544mV,满量程精度达到了1.76%,固有频率达到了13.61kHz,相对于双桥结构传感器,其综合性能提升了近85%。

To meet the requirements for vibration detection sensor in intelligent manufacturing and overcome shortcomings in the existing accelerometers including unsatisfactory performances, higher cost and bulky volume, a multiflexure piezoresistive accelerometer is developed based on microelectromechanical system （MEMS） technology. The proposed accelerometer introduces two tiny beams into the conventional quadbeam structure, which enhances the accelerometer’s natural frequency without decreasing the sensitivity. The product of natural frequency and sensitivity is regarded as the evaluation factor to determine the sensor structural dimensions, considering the constraints form analytical optimization and manufacturing process. The sensor chip is fabricated by silicon etching, boron implantation, Al sputtering and anodic bonding. The experimental results show that the developed accelerometer possesses a sensitivity of 0.544 mV per gravity acceleration, a full scale accuracy of 1.76% and natural frequency of 13.61 kHz, and can accurately acquire the acceleration signal with different frequencies. Compared with the conventional quadbeam sensor, the comprehensive property of the proposed multiflexure accelerometer is improved by 85%.