Effects of package materials on performances of a piezoresistive MEMS accelerometer

A series of experiments were carried out to explore the effects of package materials on the performances of a piezoresistive MEMS accelerometer under high-g impact. For the accelerometers packaged with ceramic and stainless steel, respectively, the residual stress and the piezoresistance variation were measured by using a Raman spectrometer before and after package. Their sensitivity and anti-overload capability were tested by applying a Machet hammer and a Hopkinson bar, respectively. And the test precision differences between the two accelerometers were analyzed in the field experiment. The experimental results show that the residual stress increments of the accelerometers with stainless steel package are higher than those of the accelerometers with ceramic package and the piezoresistance variations caused by the residual stresses are higher. But the accelerometers with stainless steel package have higher sensitivities and better anti-overload capabilities compared with the accelerometers with ceramic package.