| With the development of science and technology, accelerometers are more and more applied in industrial applications such as the vibration monitoring of machines. The vital MEMS accelerometers made by the micrcelectronics and micromachining technology have many advantages over the conventional ones and have been a hot choice for research and application. This paper will address two piezoresistive accelerometers with different ranges, in which design, fabrication, packaging and testing are also included.The effects of natural frequency and damping on dynamic performances are taken into account, followed by the damping models, which lay a good basis for the design of accelerometers. Based on the past design, new twin-mass and plate structure accelerometers are optimally designed concerning sensitivity, frequency and damping. The possibility of accelerometers with different ranges has been demonstrated by experiments.The two accelerometers with different ranges are successfully fabricated, which demonstrate a high ability to control the process. The 1# accelerometer is with a full range of3000g and the 2 # has a range of 100000g.Dynamic testing of the two kinds accelerometers are conducted relatively. Under5V excitation, the 1# sensors show a sensitivity of 48V/g and resonance frequency of 33kHz, and the 2# with a sensitivity 1.4V/g and resonance frequency 220KHz The static and stability testing of 1# sensors are also performed Base on the experiments results, special analysis on the stability of the accelerometers are given from the views of packaging stress and the temperature coefficient. Then, the factors that detennines the pulse width are also presented from the view of stress wave, while the effects of the mounting on the performances of response are analyzed based on the vibration theory. It is easily concluded that the sensors can accurately reproduce the input signal only if the mounting frequency and the resonance frequency is much higher than the input frequency... |
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