The Study Of Stress Test For MEMS

At present, the industrial degree of MEMS (Micro Electro Mechanical System) technology is low; this is because of inaccuracy material parameter, bad process control and unobvious failure mechanics. All of these problems have lead to unstable performance, low rate of finished products and bad reliability. The basic reason making above problems could not be solved for a long time is due to the weakness of measurement theory and technology foundation, so as to the problems appearing in the course of design, fabrication, package and application of microstructure and micro devices could not be found.This paper is based on the measurement on the mechanical characteristics of MEMS material, to solve the based theory and measurement technology of MEMS stress test, and to research the process residual stress on different structure parameters of surface-micromachining standardized structure, and also to research the dynamic stress test method on application and load of MEMS device. The purpose of this paper is just to supply theory and data for the structure design and process of MEMS devices, furthermore, to improve the performance, the rate of finished products and the reliability of MEMS device.This paper mainly researches the based theories and experiments methods for the stress of MEMS from two aspects. One hand, the work of this paper is based on the residual stress test of the micro-structure, based on Raman, testing the residual stress of surface-micromachining standardized structures in different structure parameters, and the corresponding stress distribution character is also studied. The other hand, dynamic stress test on driving micro-device also has been done, researching the dynamic character test of electrostatic driving micro-device based on the microsystem analyzer, then the dynamic stress test based on Raman is carried out; In addition, the preliminary measurement of the dynamic stress for electromagnetic loading micro-structure is also implemented.The chief studied results are as follows:1. The residual stress distribution character of surface-micromachining standardized structures is obtained by using stress measurement system based on Raman.2. Micro-system analyzer and Raman are used to test the dynamic stress on micro-structure for the first time. The dynamic stress deduced from the dynamic test result of micro-structure are associated with that is stimulated in ANSYS, The result indicates that this method can also be used to test the distribution character of a line in micro-structure.3. Bending the electromagnetism and Raman spectroscopy for stress measurement is present for the first time. The curve between the stress of the tested point and the voltage pressed on magnet is obtained, and the rupture margin is also got from the test result.