一种汽车碰撞试验用低阻尼宽频响加速度传感器

A Low Damping Wide Frequency Response Range Accelerometer for Automobile Crash Testing

基于硅的压阻效应,利用微电子机械系统(MEMS)技术研制了一种汽车碰撞试验用低阻尼、宽频响的加速度传感器。为了满足小体积和高性能的要求,传感器采用了L型梁-质量块结构;并设计了一种全方位抗过载的新颖限位结构,保证了低阻尼传感器高过载、高可靠性。传感器芯片采用绝缘体上硅(SOI)片加工,并利用硅硅键合与共晶键合工艺相结合实现了圆片级气密封装,具有易于批量生产的优势,可以广泛应用于汽车碰撞试验。封装后的传感器采用振动法和冲击法进行性能测试,测试结果表明,传感器的量程范围大于2 000g,阻尼比为0.023,谐振频率约27.6 kHz,带内平坦度在±4%范围内带宽大于5 kHz,传感器在多次承受20 000g的冲击下没有失效。

Based on the silicon piezoresistive effect,a kind of accelerometer with low damping and wide frequency response range was developed for automobile crash testing by the micro-electromechanical system（MEMS）technology.For meeting the requirements of small volume and high performance,an L-shaped beam-mass block structure was adopted in the accelerometer.To ensure high overload and high reliability of the accelerometer with low damping,a new all-dimensional anti-overload limit structure was designed.The accelerometer chip was fabricated by using the silicon-on-insulator（SOI）wafer,and the wafer level hermetic packaging was achieved by the combined technology of Si-Si bonding and eutectic bonding.The accelerometer has the advantage of the mass production,thus can be widely applied in the automobile crash test.The performance test of the packaged accelerometer was carried out by the vibration method and shocking method.The test results show that the full measure range of the accelerometer is more than 2 000 g,the damping ratio is 0.023,the resonance frequency is about 27.6 kHz,and the bandwidth is greater than 5 kHz with the in-band flatness of±4%.No failure of the accelerometer occurs after the repeated shocks under 20 000 g.