Experimental Research On Buckling Of Thin Films In Nano-scale Under Mechanical-Thermal Coupling Load And Thermal Fatiguein Research

Recently great interest has been paid to the delamination and buckling of thin films deposited on substrates for their wide application, because delamination and buckling are the main damage mechanism. In this paper, the mechanical and thermal properties of thin film materials with 500nm thickness under mechanical and thermal loads are measured and characterized. Investigation of thin film buckling is important for life prediction of MEMS device.The model of film deposited on substrate is widely used in MEMS. The model of film deposited on substrate will endure mechanical loads besides thermal load for its generating quality of heat.This paper focuses on the process of buckling of thin compressed Ti/Ni,Cu,AL films under mechanical and thermal loads which is deposited on an organic glass substrate utilizing an optical microscope. In order to simulate the films at work which endure compound loads and to produce regular buckle mode, external uniaxial compression and thermal load are subjected to the specimen. During the trial,the mechanical load is exerted by the symmetric loading device. The thermal load is exerted by the electrical film.The qualitative analysis of the model of film deposited on substrate which is under mechanical and thermal loading is made for limitation of method of technology and knowledge. The model of film deposited on substrate is always pre-fixed in the MEMS, so it will endure mechanical load in room environment. Then the model of film deposited on substrate will work and generate quality of heat so it will endure effect which is caused by thermal load. In the trials,it is needed to measure the temperatures of the thin film deposited on substrate which is under mechanical-thermal coupling loads by using thermoelectric couple. Inder to control the thermal load that simulate the range of temperature accords with the temperature range of the MEMS,so we designed a circuitry for control the thermal load. So the result of the research has its practical value.The size and number of the delamination and buckling of the film will differentiate with different pre-fixed mechanical load. The author has made research on the thin film with different per-fixed mechanical loads and analyzed the delamination and buckling of the film by using an optical microscope. In the end of the trials,we got the optimized conditions of the film under mechanical and thermal load by using qualitative analysis.In this paper, the author made diathermanous and qualitative analysis about the system of film and substrate with finite element method. Furthermore, the author got distributing of temperature, distributing of heat stress results about the system of the film and substrate. Some compare about the results is included. Eexplaining the phenomenon of experimentation...