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The Reliability Analysis Of Surface-Micromachined Microcantilever Subjected To Vibration Environment

Posted on:2007-05-05Degree:MasterType:Thesis
Country:ChinaCandidate:X L XuFull Text:PDF
GTID:2178360212965462Subject:Microelectronics and Solid State Electronics
Abstract/Summary:PDF Full Text Request
For many MEMS applications that putting them into large-scale products is more challenging than expected and that the time to marked takes often too long. One of the reasons is that reliability related issues are often only the very last step that is considered in the development of new MEMS. Reliability may cause major delays in the product development going together with high costs. So people have put more and more attention to the reliability design of MEMS. So far, people mainly analyze MEMS reliability by experiments and theoretical researches of reliability, which are more efficient and more cost-saving, are very scarce. Therefore, it is quite necessary to perform reliability analysis theoretically, which will be a good guide for MEMS design.Theoretical research on the reliability of MEMS in vibration environment is one of the most important aspects of MEMS Reliability, for exposure of MEMS to vibrating environment can occur during transportation and operation and it often makes MEMS not able to work properly. MEMS under vibrating load can fail in several different modes including fracture, stiction, delamination, wear and so on. So this paper will focus on the study of MEMS reliability under vibration.In this paper, as the first step we analyze the mechanical response, including displacement and stress, of a vibrating-loaded cantilever, which is the fundamental element of MEMS and is widely used in microstructures. For their micro dimensions, the forces micro-cantilevers received are quite different from the macroscopical counterparts, so the damping forces and some forces between surfaces are analyzed and used in the bending equation of beams. Based on the stress distribution and the fracture intensity theory of the structure, the fracture characteristics are studied and the trend between the dimensions of the beam and displacement as well as stress is acquired, which will benefit the intensity design of MEMS. From the view that the system is the most stable when the system energy is the lowest, the criteria for judging whether stiction between surfaces of the beam would happen during vibration is deduced. Based on the displacement distribution and the stiction criterion, the adhesion failure is predicted. Finally, the research and methodology on fatigue failure by other researchers are reviewed and based on the dynamic response of the beam and the S-N curve of poly-silicon, fatigue characteristics of the cantilever are analyzed by ANSYS software and the reasons for the possible deviation between the simulation and the experiments are offered.
Keywords/Search Tags:MEMS, reliability, cantilever, vibration, dynamical response
PDF Full Text Request
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