基于鼓膜法的薄膜力学性能测试研究

Research on mechanical properties of thin films based on bulge test

采用自行研制的鼓膜实验装置,结合迈克尔逊激光干涉位移测量技术,获取薄膜的变形值与压力值之间的关系曲线,以实现薄膜试样力学性能的测试。对鼓膜法测试薄膜力学性能的现状做了评述;对实验原理以及装置设计进行论述;进行实验测量,并对实验结果进行有限元分析与仿真。对纯铝薄膜(纯度99.9%,厚为210μm)进行鼓膜实验,测得其弹性模量E为68.3 GPa,与资料结果基本一致,说明研制的鼓膜实验装置测量薄膜力学性能方法切实可行。实验装置对于在微/纳机电系统(MEMS/NEMS)中广泛应用的薄膜材料的力学性能表征具有十分重要的意义。

To determine the mechanical properties of thin films by obtaining the relation curve of continuous bugling deformation and corresponding load,bulge test experiment equipment in conjunction with Michelson interferometry displacement measuring system is made. Firstly,the current status of bulge test methods for measuring mechanical properties of thin films is reviewed. Then the principle of the testing method,the design of blister experiment in the test is introduced. Lastly,finite element method is used to simulate the bulge test of the samples. In order to validate the method,Al thin films（ purity is 99. 9 %; thickness is 210 μm） are tested by the developed method. The elastic modulus E of the Al film is measured to be 68. 3 GPa,which is in an agreement with the given material reference values. It can thus be concluded that it is feasible to measure mechanical properties of thin films by our devised bulge testing setup. It is vitally significant for the application of our developed experiment setup to characterize thin films widely used in the field of the micro/nano-electro-mechanical system（ MEMS/NEMS）.