Effects of package on the performance of MEMS piezoresistive accelerometers

Package is one of the key technologies for MEMS accelerometers. This paper investigated the influence of package on performances of custom-designed MEMS piezoresistive accelerometer. Based on the designed package process, the effect of die adhesive and potting materials on the sensor sensitivity and residual stress were studied by theory analysis and experimental test. The results showed that: with more quantity of die adhesive when the thickness was fixed, the sensitivity of MEMS piezoresistive accelerometer was much smaller; in addition, with thicker die adhesive, the accelerometer had much bigger sensitivity and much smaller residual stress increment after the die attach process. Meanwhile, the sensitivity was proportional to the density of potting material, and it varied with the elastic modulus.